WorldWideScience

Sample records for voigt hartmut ritter

  1. Hartmut Lichtenthaler: an authority on chloroplast structure and isoprenoid biochemistry.

    Science.gov (United States)

    Sharkey, Thomas D; Govindjee

    2016-05-01

    We pay tribute to Hartmut Lichtenthaler for making important contributions to the field of photosynthesis research. He was recently recognized for ground-breaking discoveries in chloroplast structure and isoprenoid biochemistry by the Rebeiz Foundation for Basic Research (RFBR; http://vlpbp.org/ ), receiving a 2014 Lifetime Achievement Award for Photosynthesis. The ceremony, held in Champaign, Illinois, was attended by many prominent researchers in the photosynthesis field. We provide below a brief note on his education, and then describe some of the areas in which Hartmut Lichtenthaler has been a pioneer.

  2. Erzählen lyrische Texte? Hartmut Bleumers und Caroline Emmelius’ Sammelband zu lyrischen Narrationen und narrativer Lyrik im Mittelalter [Hartmut Bleumer / Caroline Emmelius (Hg.: Lyrische Narrationen – narrative Lyrik. Gattungsinterferenzen in der mittelalterlichen Literatur. Berlin / New York 2011

    Directory of Open Access Journals (Sweden)

    Frauke Bode

    2015-06-01

    Full Text Available Rezension zu / Review of:Hartmut Bleumer / Caroline Emmelius (Hg.: Lyrische Narrationen – narrative Lyrik. Gattungsinterferenzen in der mittelalterlichen Literatur. Berlin / New York 2011

  3. Voigt-wave propagation in active materials

    CERN Document Server

    Mackay, Tom G

    2015-01-01

    If a dissipative anisotropic dielectric material, characterized by the permittivity matrix $\\underline{\\underline{\\epsilon}}$, supports Voigt-wave propagation, then so too does the analogous active material characterized by the permittivity matrix $\\underline{\\underline{{\\tilde{\\epsilon}}}}$, where $\\underline{\\underline{{\\tilde{\\epsilon}}}}$ is the hermitian conjugate of $\\underline{\\underline{\\epsilon}}$. Consequently, a dissipative material that supports Voigt-wave propagation can give rise to a material that supports the propagation of Voigt waves with attendant linear gain in amplitude with propagation distance, by infiltration with an active dye.

  4. Some Representations of Unified Voigt Functions

    Institute of Scientific and Technical Information of China (English)

    M. KAMARUJJAMA; Dinesh SINGH

    2005-01-01

    The authors derive a set of unified representations of the Voigt functions in terms of familiar special functions of Mathematical Physics. Some deductions from these representations are also considered.

  5. Controlling Voigt waves by the Pockels effect

    CERN Document Server

    Mackay, Tom G

    2014-01-01

    Voigt wave propagation was investigated in a homogenized composite material (HCM) arising from a porous electro--optic host material infiltrated by a fluid of refractive index $n_a$. The constitutive parameters of the HCM were estimated using the extended Bruggeman homogenization formalism. Numerical studies revealed that the directions which support Voigt wave propagation in the HCM could be substantially controlled by means of an applied dc electric field. Furthermore, the extent to which this control could be achieved was found to be sensitive to the porosity of the host material, the shapes, sizes and orientations of the pores, as well as the refractive index $n_a$. These findings may be particularly significant for potential technological applications of Voigt waves, such as in optical sensing.

  6. Generalized Voigt functions and their derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Sampoorna, M. [Indian Institute of Astrophysics, Koramangala, Bangalore 560 034 (India) and Laboratoire Cassiopee (CNRS, UMR 6202), Observatoire de la Cote d' Azur, BP 4229, F-06304 Nice Cedex 4 (France)]. E-mail: sampoorna@iiap.res.in; Nagendra, K.N. [Indian Institute of Astrophysics, Koramangala, Bangalore 560 034 (India); Laboratoire Cassiopee (CNRS, UMR 6202), Observatoire de la Cote d' Azur, BP 4229, F-06304 Nice Cedex 4 (France); Frisch, H. [Laboratoire Cassiopee (CNRS, UMR 6202), Observatoire de la Cote d' Azur, BP 4229, F-06304 Nice Cedex 4 (France)

    2007-03-15

    This paper deals with a special class of functions called generalized Voigt functions H{sup (n)}(x,a) and G{sup (n)}(x,a) and their partial derivatives, which are useful in the theory of polarized spectral line formation in stochastic media. For n=0 they reduce to the usual Voigt and Faraday-Voigt functions H(x,a) and G(x,a). A detailed study is made of these new functions. Simple recurrence relations are established and employed for the calculation of the functions themselves and of their partial derivatives. Asymptotic expansions are given for large values of x and a. They are used to examine the range of applicability of the recurrence relations and to construct a numerical algorithm for the calculation of the generalized Voigt functions and of their derivatives valid in a large (x,a) domain. It is also shown that the partial derivatives of the usual H(x,a) and G(x,a) can be expressed in terms of H{sup (n)}(x,a) and G{sup (n)}(x,a)

  7. Relationship among the Voigt integral and the dispersion function of plasma. Additional methods for estimating the Voigt integral; Relacion entre la integral de Voigt y la funcion de dispersion del plasma. Metodos adicionales para estimar la integral de Voigt

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez D, H.; Flores L, H.; Cabral P, A.; Bravo O, A

    1990-05-15

    A relationship among the Lorentzian-Gaussian profile convolution and the Plasma Dispersion Function is presented; thus, the methods available to calculate the latter serve also to calculate the Voigt profile. (Author)

  8. Voigt's transformations and the beginning of the relativistic revolution

    CERN Document Server

    Heras, Ricardo

    2014-01-01

    In 1887 W. Voigt published a paper on the Doppler effect, which marked the birth of the relativistic revolution. In his paper Voigt derived a set of spacetime transformations by demanding covariance to the homogeneous wave equation in inertial frames, and this was an application of the first postulate of special relativity. Voigt assumed in his derivation the invariance of the speed of light in inertial frames, and this is the second postulate of special relativity. He then applied the postulates of special relativity to the wave equation 18 years before Einstein explicitly enunciated these postulates. Voigt's transformations questioned the Newtonian notion of absolute time for the first time in physics by suggesting that the absolute time should be replaced by the non-absolute time $t'=t-vx/c^2$. Unfortunately, Voigt's 1887 paper was not appreciated by most physicists of that time. Voigt's transformations do not form a group and are an example of the conformal symmetry of spacetime. In the present paper we e...

  9. Computational aspects of speed-dependent Voigt profiles

    Science.gov (United States)

    Schreier, Franz

    2017-01-01

    The increasing quality of atmospheric spectroscopy observations has indicated the limitations of the Voigt profile routinely used for line-by-line modeling, and physical processes beyond pressure and Doppler broadening have to be considered. The speed-dependent Voigt (SDV) profile can be readily computed as the difference of the real part of two complex error functions (i.e. Voigt functions). Using a highly accurate code as a reference, various implementations of the SDV function based on Humlíček's rational approximations are examined for typical speed dependences of pressure broadening and the range of wavenumber distances and Lorentz to Doppler width ratios encountered in infrared applications. Neither of these implementations appears to be optimal, and a new algorithm based on a combination of the Humlíček (1982) and Weideman (1994) rational approximations is suggested.

  10. On the propagation of Voigt waves in energetically active materials

    Science.gov (United States)

    Mackay, Tom G.; Lakhtakia, Akhlesh

    2016-11-01

    If Voigt-wave propagation is possible in a dissipative anisotropic dielectric material characterised by the permittivity dyadic \\mathop{\\varepsilon }\\limits\\raise{2pt=}, then it is also possible in the analogous energetically active material characterised by the permittivity dyadic \\mathop{\\tilde{\\varepsilon }}\\limits\\raise{2pt=}, where \\mathop{\\tilde{\\varepsilon }}\\limits\\raise{2pt=} is the hermitian conjugate of \\mathop{\\varepsilon }\\limits\\raise{2pt=}. This symmetry follows directly from a theoretical analysis of the necessary and sufficient conditions for Voigt-wave propagation in anisotropic materials. As a consequence of this symmetry, a porous dissipative material that exhibits Voigt-wave propagation can be used to construct a material that allows the propagation of Voigt waves with attendant linear gain in amplitude with propagation distance, by means of infiltration with an electrically or optically activated dye, for example. This phenomenon is captured by the Bruggeman formalism for homogenised composite materials based on isotropic dielectric component materials that are randomly distributed as oriented spheroidal particles.

  11. Comparison between classical Kelvin-Voigt and fractional derivative Kelvin-Voigt models in prediction of linear viscoelastic behaviour of waste activated sludge.

    Science.gov (United States)

    Farno, Ehsan; Baudez, Jean-Christophe; Eshtiaghi, Nicky

    2017-09-22

    Appropriate sewage sludge rheological models are essential for computational fluid dynamic simulation of wastewater treatment processes, in particular aerobic and anaerobic digestions. The liquid-like behaviour of sludge is well documented but the solid-like behaviour remains poorly described despite its importance for dead-zone formation. In this study, classical Kelvin-Voigt model, commonly used for sludge in literature, were compared with fractional derivative Kelvin-Voigt model regarding their predictive ability for describing the solid-like behaviour. Results showed that the fractional Kelvin-Voigt model best fitted the experimental data obtained from creep and frequency sweep tests. Whereas, classical Kelvin-Voigt could not fit the frequency sweep data as this model is not a function of angular velocity. Also, the Kelvin-Voigt model was unable to predict the creep data at low stresses. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Humboldt, Cotta, Ritter. Eine Miszelle über die Arbeit an einer Edition

    Directory of Open Access Journals (Sweden)

    Ulrike Leitner

    2008-04-01

    Full Text Available Article in German, Abstracts in English, German and SpanishThrough the work on editing projects sometimes historical and biographical details are discovered. In this paper a letter from A. v. Humboldt to his publisher J. G. v. Cotta serves as an example of how the correct date of a wrongly dated letter could be found. The necessary research to answer this question also brought to light some new facts as to a meeting between Humboldt and geographer C. Ritter in Paris in 1824. We also learn about some topics on which Humboldt was working at the time and about his relationship to the French Court.

  13. Synthesis of amidoalkyl naphthol via Ritter-type reaction catalysed by heteropolyanion-based ionic liquid

    Indian Academy of Sciences (India)

    Fang Dong; Jiang Chenning; Zhu Ting; Yang Jinming

    2013-07-01

    A facile and efficient procedure for the preparation of amidoalkyl naphthols via a Ritter-type reaction of 2-naphthol, aromatic aldehydes and amide in the presence of heteropolyanion-based functionalized ionic liquid has been described. The one-pot solvent-free three-component reaction is accomplished at 110°C for 5-10 min in reasonable to good yield ranging from 73% to 94%. The catalyst could be recovered and reused at least six times without noticeably decreasing the catalytic activity.

  14. Nafion®-catalyzed microwave-assisted Ritter reaction: An atom-economic solvent-free synthesis of amides

    Science.gov (United States)

    An atom-economic solvent-free synthesis of amides by the Ritter reaction of alcohols and nitriles under microwave irradiation is reported. This green protocol is catalyzed by solid supported Nafion®NR50 with improved efficiency and reduced waste production.

  15. Fast and accurate expression for the Voigt function. Application to the determination of uranium M linewidths

    Energy Technology Data Exchange (ETDEWEB)

    Limandri, Silvina P. [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000, Cordoba (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas de la Republica Argentina (Argentina); Bonetto, Rita D. [Consejo Nacional de Investigaciones Cientificas y Tecnicas de la Republica Argentina (Argentina) and Centro de Investigacion y Desarrollo en Ciencias Aplicadas Dr. Jorge Ronco, Calle 47 No 257, 1900 La Plata, Argentina; Facultad de Ciencias Exactas y Facultad de Ingenieria de la UNLP, La Plata (Argentina); Di Rocco, Hector O. [Consejo Nacional de Investigaciones Cientificas y Tecnicas de la Republica Argentina (Argentina); Instituto de Fisica Arroyo Seco, Facultad de Ciencias Exactas, Universidad Nacional del Centro, Pinto 399, 7000 Tandil (Argentina); Trincavelli, Jorge C. [Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000, Cordoba (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas de la Republica Argentina (Argentina)], E-mail: jorge@quechua.fis.uncor.edu

    2008-09-15

    The Voigt function is the convolution between a Gaussian and a Lorentzian distribution. The numerical implementation of this function is required in diverse areas of physics and applied mathematics. An explicit representation for the Voigt function is developed in terms of series of trigonometric and hyperbolic functions. The obtained expression permits a very fast evaluation of Voigt profiles with a degree of accuracy higher than the one required for spectroscopy applications. In addition, this expression is implemented in a numerical algorithm of parameter optimization in electron probe microanalysis, and applied to determine natural linewidths for several transitions to the uranium M levels.

  16. Estudo fitoquímico e atividade antimicrobiana de Pilosocereus pachycladus F. RITTER (CACTACEAE)

    OpenAIRE

    Brito Filho, Severino Gonçalves de

    2015-01-01

    O gênero Pilosocereus pertencente à família Cactaceae se destaca por possuir o maior número de espécies, com 35 exemplares distribuídos desde o México até o Paraguai, sendo o Brasil o país com o maior número de espécies distribuídas em diferentes ambientes, incluindo caatingas, restingas e campos rupestres. A espécie Pilosocereus pachycladus F. RITTER, conhecido como "Facheiro", é utilizada pela medicina popular contra inflamação prostática. O estudo fitoquímico pioneiro desta espécie levou a...

  17. Fast Fourier transform for Voigt profile: Comparison with some other algorithms

    Science.gov (United States)

    Abousahl, S.; Gourma, M.; Bickel, M.

    1997-02-01

    There are different algorithms describing the Voigt profile. This profile is encountered in many areas of physics which could be limited by the resolution of the instrumentation used to measure it and by other phenomena like the interaction between the emitted waves and matter. In nuclear measurement field, the codes used to characterise radionucleides rely on algorithms resolving the Voigt profile equation. The Fast Fourier Transform (FFT) algorithm allows the validation of some algorithms.

  18. Sanitation: No hot chocolate. Insulation of pipelines and component parts in the Ritter Sport factory at Waldenbuch; Sanierung: Keine heisse Schokolade. Daemmung von Rohrleitungen und Anlagenteilen im Ritter Sport Werk Waldenbuch

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2002-12-13

    In the chocolate factory Ritter Sport the heating systems were retrofitted in the last months. Two separated central heating plants were unified in a central block unit with cogeneration components. The piping system was decartelized and optimized. During the insulation of pipelines with elastomer high temperature materials high hygienical standards have to be kept. Furthermore the new lines have to be installed and insulated during running production because hot water supply shouldn't be interrupted. (GL) [German] Isolierungen in der Industrie muessen haeufig hohen Anforderungen genuegen und unter erschwerten Bedingungen durchgefuehrt werden. In der Schokoladenfabrik Ritter Sport in Waldenbuch wurde in den vergangenen Monaten die Heizungsanlage saniert: Dabei wurden zwei raeumlich getrennte Heizzentralen auf ein zentrales Blockheizkraftwerk umgeruestet. Gleichzeitig wurde das Rohrleitungsnetz entflochten und optimiert. Bei der Daemmung der Heizungsrohrleitungen mit einem elastomeren Hochtemperaturdaemmstoff mussten nicht nur die hohen Hygiene-Standards der Ritter Sport GmbH eingehalten werden, die neuen Leitungen mussten zudem bei laufender Produktion verlegt und gedaemmt werden, da die Heizwasserversorgung nicht unterbrochen werden durfte. (orig.)

  19. Evolution equations of the probabilistic generalization of the Voigt profile function

    CERN Document Server

    Pagnini, Gianni

    2007-01-01

    The spectrum profile that emerges in molecular spectroscopy and atmospheric radiative transfer as the combined effect of Doppler and pressure broadenings is known as the Voigt profile function. Because of its convolution integral representation, the Voigt profile can be interpreted as the probability density function of the sum of two independent random variables with Gaussian density (due to the Doppler effect) and Lorentzian density (due to the pressure effect). Since these densities belong to the class of symmetric L\\'evy stable distributions, a probabilistic generalization is proposed as the convolution of two arbitrary symmetric L\\'evy densities. We study the case when the widths of the considered distributions depend on a scale-factor $\\tau$ that is representative of spatial inhomogeneity or temporal non-stationarity. The evolution equations for this probabilistic generalization of the Voigt function are here introduced and interpreted as generalized diffusion equations containing two Riesz space-fracti...

  20. Voigt waves in homogenized particulate composites based on isotropic dielectric components

    CERN Document Server

    Mackay, Tom G

    2011-01-01

    Homogenized composite materials (HCMs) can support a singular form of optical propagation, known as Voigt wave propagation, while their component materials do not. This phenomenon was investigated for biaxial HCMs arising from nondissipative isotropic dielectric component materials. The biaxiality of these HCMs stems from the oriented spheroidal shapes of the particles which make up the component materials. An extended version of the Bruggeman homogenization formalism was used to investigate the influence of component particle orientation, shape and size, as well as volume fraction of the component materials, upon Voigt wave propagation. Our numerical studies revealed that the directions in which Voigt waves propagate is highly sensitive to the orientation of the component particles and to the volume fraction of the component materials, but less sensitive to the shape of the component particles and less sensitive still to the size of the component particles. Furthermore, whether or not such an HCM supports Vo...

  1. Simple atmospheric transmittance calculation based on a Fourier-transformed Voigt profile.

    Science.gov (United States)

    Kobayashi, Hirokazu

    2002-11-20

    A method of line-by-line transmission calculation for a homogeneous atmospheric layer that uses the Fourier-transformed Voigt profile is presented. The method is based on a pure Voigt function with no approximation and an interference term that takes into account the line-mixing effect. One can use the method to calculate transmittance, considering each line shape as it is affected by temperature and pressure, with a line database with an arbitrary wave-number range and resolution. To show that the method is feasible for practical model development, we compared the calculated transmittance with that obtained with a conventional model, and good consistency was observed.

  2. Iris Wigger and Sabine Ritter, editors. Racism and Modernity. Festschrift for Wulf D. Hund

    Directory of Open Access Journals (Sweden)

    Hernán Andrés Pulido Londoño

    2013-03-01

    Full Text Available Este volumen, editado por Iris Wigger y Sabine Ritter, reúne diecisiete ensayos hermanados por la reflexión conceptual e historiográfica sobre las prácticas y discursos racistas que apuntalaron la emergencia de las sociedades modernas. La colección honra los aportes académicos de Wulf D. Hund (1946, destacado investigador alemán, quien ha desarrollado fructíferos análisis críticos dedicados —como señalan las editoras— a una disección histórico-sociológica de los discursos raciales en el pensamiento europeo y la historia global. En efecto, esta colección está estrechamente relacionada con una de las propuestas centrales de Hund: el examen de los racismos como parte de procesos de socialización negativa consustanciales a la modernidad. Normal 0 21 false false false ES X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:12.0pt; mso-bidi-font-size:10.0pt; font-family:"Times New Roman","serif"; mso-fareast-language:EN-US;}

  3. Seismic wave propagating in Kelvin-Voigt homogeneous visco-elastic media

    Institute of Scientific and Technical Information of China (English)

    YUAN; Chunfang; PENG; Suping; ZHANG; Zhongjie; LIU; Zhenkuan

    2006-01-01

    This paper studies, under a small disturbance, the responses of seismic transient wave in the visco-elastic media and the analytic solution of the corresponding third-order partial differential equation. A plane wave solution of Kelvin-Voigt homogeneous visco-elastic third-order partial differential equation with a pulse source is obtained. By the principle of pulse stacking of particle vibration, the result is extended to the solution of Kelvin-Voigt homogeneous visco-elastic third-order partial differential equation with any source. The velocities of seismic wave propagating and the attenuation of seismic wave in Kelvin-Voigt homogeneous visco-elastic media are discussed. The velocities of seismic wave propagating and the coefficient of attenuation of seismic wave in Kelvin-Voigt homogeneous visco-elastic media are derived, expressed as functions of density of the media, elastic modulus and visco-elastic coefficient. These results can be applied in inversing lithology parameters in geophysical prospecting.

  4. Mida suudab muusikateraapia? / Melanie Voigt, Esa Ala-Ruona ; inetrvjueerinud Kristel Kossar

    Index Scriptorium Estoniae

    Voigt, Melanie

    2012-01-01

    Eesti Muusika- ja Teatriakadeemias toimunud Euroopa Muusikateraapia Konföderatsiooni peaassambleel ja sümpoosionil ettekannetega esinenud muusikaterapeudid Malanie Voigt Saksamaalt ja Esa Ala-Ruona Soomest räägivad tööst puuetega lastega ja tööstressist ning heliilmast

  5. Mida suudab muusikateraapia? / Melanie Voigt, Esa Ala-Ruona ; inetrvjueerinud Kristel Kossar

    Index Scriptorium Estoniae

    Voigt, Melanie

    2012-01-01

    Eesti Muusika- ja Teatriakadeemias toimunud Euroopa Muusikateraapia Konföderatsiooni peaassambleel ja sümpoosionil ettekannetega esinenud muusikaterapeudid Malanie Voigt Saksamaalt ja Esa Ala-Ruona Soomest räägivad tööst puuetega lastega ja tööstressist ning heliilmast

  6. Preparation of different amides via Ritter reaction from alcohols and nitriles in the presence of silica-bonded N- propyl sulphamic acid (SBNPSA) under solvent-free conditions

    Indian Academy of Sciences (India)

    Maryam-Sadat Shakeri; Hassan Tajik; Khodabakhsh Niknam

    2012-09-01

    A number of methods have been proposed for the modification of the Ritter reaction. However, many of these methods involve the use of strongly acidic conditions, stoichiometric amounts of reagents, harsh reaction conditions and extended reaction times. Therefore, the development of mild, efficient, convenient and benign reagents for the Ritter reaction is desirable. In this research, we have developed a clean and environmentally friendly protocol for the synthesis of amides by using different benzylic or tertiary alcohols and different nitriles in the presence of silica-bonded N- propyl sulphamic acid (SBNPSA) as catalyst under solvent-free conditions in high yields.

  7. Mind the Gap when Data Mining the Ritter-Kolb Cataclysmic Variable Catalogue

    Science.gov (United States)

    Sparks, Warren M.; Sion, Edward M.

    2017-01-01

    The cataclysmic variable (CV) binary consists of a white dwarf primary and a low-mass secondary which overflows its Roche lobe. The Ritter-Kolb catalogue (2003, A&A, 404, 301) is a collection (~1000) of CV binaries and related objects. We have mined this catalogue for CVs with unevolved secondaries whose mass ratio (secondary/primary) is known (~130). A plot of the secondary mass verses the log of the orbital period exhibits the well-known period gap at 2-3 hrs. In addition, this plot shows that the secondary masses just above the period gap are collectively much larger than those just below. The average of the first ten secondary masses above the period is 180% larger than the average below the gap.The disrupted magnetic braking hypothesis (Howell, Nelson, and Rappaport 2001, ApJ, 550, 897 [HNR]) predicts that when the secondary becomes fully convective, the magnetic braking, which has driven the secondary out of thermal equilibrium, stops. In adjusting to thermal equilibrium the secondary shrinks below its Roche lobe and no longer loses mass. The binary system ceases to appear as a CV until gravitational radiation loss brings the secondary back in contact with its Roche lobe. This scenario is at odds with the apparent secondary mass loss across the period gap. Either the secondary continues to lose mass while crossing the period gap or the secondary masses are miscalculated!Magnetic braking causes the secondary to expand or inflate larger than its single star counterpart. Any orbital parameter calculation which assumes a radius-mass relationship based on single main-sequence stars will overestimate the mass of the secondary. We can approximate this mass overestimation from calculations by HNR which take into account the thermal heating from magnetic braking. Using this approximation as a first-order correction to the secondary mass, we replot the deflated secondary mass versus the binary period. The deflated masses immediately above and below the period gap are

  8. Synthesis Organonitrogen Compounds from Patchouli Alcohol Through Ritter Reaction with Acetonitrile and Its Toxicity to Artemia salina Leach.

    Directory of Open Access Journals (Sweden)

    Khoirun Nisyak

    2013-03-01

    Full Text Available Patchouli oil contains a compound with biological activities to human body called the patchouli alcohol that can be further developed in medical field. This research aimed to synthesize organonitrogen compound from patchouli alcohol through Ritter reaction with acetonitrile and discover its toxicity towards Artemia salina Leach. The isolation of patchouli alcohol from patchouli oil using fractional distillation under reduced pressure method. The synthesis of organonitrogen compound is done at room temperature with the mol ratio of patchouli alcohol: acetonitrile: sulfuric acid is 1:1,5:4 for 24 hours. The result showed that the amount of patchouli alcohol produced from fractional distillation is 65,25%. The main product yielded from the synthesis between patchouli alcohol and acetonitrile through Ritter reaction is 36,93 % of N-(4,8a,9,9-tetramethyl decahydro-1,6-methanonaphtalene-1-yl acetamide. Starting material used have LC50 of 77,39 ppm. The product of synthesis have higher toxicity level than starting material, which have LC50 value is 10,39 ppm with the potential as medical compounds.

  9. Detection of Voigt Spectral Line Profiles of Hydrogen Radio Recombination Lines toward Sagittarius B2(N)

    CERN Document Server

    von Prochazka, Azrael A; Balser, Dana S; Ryans, Robert S I; Marshall, Adele H; Schwab, Fredric R; Hollis, Jan M; Jewell, Philip R; Lovas, Frank J

    2010-01-01

    We report the detection of Voigt spectral line profiles of radio recombination lines (RRLs) toward Sagittarius B2(N) with the 100-m Green Bank Telescope (GBT). At radio wavelengths, astronomical spectra are highly populated with RRLs, which serve as ideal probes of the physical conditions in molecular cloud complexes. An analysis of the Hn(alpha) lines presented herein shows that RRLs of higher principal quantum number (n>90) are generally divergent from their expected Gaussian profiles and, moreover, are well described by their respective Voigt profiles. This is in agreement with the theory that spectral lines experience pressure broadening as a result of electron collisions at lower radio frequencies. Given the inherent technical difficulties regarding the detection and profiling of true RRL wing spans and shapes, it is crucial that the observing instrumentation produce flat baselines as well as high sensitivity, high resolution data. The GBT has demonstrated its capabilities regarding all of these aspects,...

  10. Covering the Bases with Young Adult Literature: Implementing John H. Ritter's "Choosing Up Sides" and "Over the Wall" as Touchstone Texts in a Middle School Language Arts Program.

    Science.gov (United States)

    Ladd, Patricia K.

    2000-01-01

    Supports ideas for implementing John H. Ritter's "Choosing Up Sides" and "Over the Wall" as touchstone texts in a middle school language arts program. Discusses these two novels and the use and power of metaphors. Reveals literary connections made by young adolescent readers and writers strengthening overall comprehension, synthesis and analysis…

  11. Digital signal processor-based high-precision on-line Voigt lineshape fitting for direct absorption spectroscopy.

    Science.gov (United States)

    Xu, Lijun; Liu, Chang; Zheng, Deyan; Cao, Zhang; Cai, Weiwei

    2014-12-01

    To realize on-line high-accuracy measurement in direct absorption spectroscopy (DAS), a system-on-chip, high-precision digital signal processor-based on-line Voigt lineshape fitting implementation is introduced in this paper. Given that the Voigt lineshape is determined by the Gauss full width at half maximum (FWHM) and Lorentz FWHM, a look-up table, which covers a range of combinations of both, is first built to achieve rapid and accurate calculation of Voigt lineshape. With the look-up table and raw absorbance data in hand, Gauss-Newton nonlinear fitting module is implemented to obtain the parameters including both the Gauss and Lorentz FWHMs, which can be used to calculate the integrated absorbance. To realize the proposed method in hardware, a digital signal processor (DSP) is adopted to fit the Voigt lineshape in a real-time DAS measurement system. In experiment, temperature and H2O concentration of a flat flame are recovered from the transitions of 7444.36 cm(-1) and 7185.6 cm(-1) by the DSP-based on-line Voigt lineshape fitting and on-line integral of the raw absorbance, respectively. The results show that the proposed method can not only fit the Voigt lineshape on-line but also improve the measurement accuracy compared with those obtained from the direct integral of the raw absorbance.

  12. Spectral Line-Shape Model to Replace the Voigt Profile in Spectroscopic Databases

    Science.gov (United States)

    Lisak, Daniel; Ngo, Ngoc Hoa; Tran, Ha; Hartmann, Jean-Michel

    2014-06-01

    The standard description of molecular line shapes in spectral databases and radiative transfer codes is based on the Voigt profile. It is well known that its simplified assumptions of absorber free motion and independence of collisional parameters from absorber velocity lead to systematic errors in analysis of experimental spectra, and retrieval of gas concentration. We demonstrate1,2 that the partially correlated quadratic speed-dependent hardcollision profile3. (pCqSDHCP) is a good candidate to replace the Voigt profile in the next generations of spectroscopic databases. This profile takes into account the following physical effects: the Doppler broadening, the pressure broadening and shifting of the line, the velocity-changing collisions, the speed-dependence of pressure broadening and shifting, and correlations between velocity- and phase/state-changing collisions. The speed-dependence of pressure broadening and shifting is incorporated into the pCqSDNGP in the so-called quadratic approximation. The velocity-changing collisions lead to the Dicke narrowing effect; however in many cases correlations between velocityand phase/state-changing collisions may lead to effective reduction of observed Dicke narrowing. The hard-collision model of velocity-changing collisions is also known as the Nelkin-Ghatak model or Rautian model. Applicability of the pCqSDHCP for different molecular systems was tested on calculated and experimental spectra of such molecules as H2, O2, CO2, H2O in a wide span of pressures. For all considered systems, pCqSDHCP is able to describe molecular spectra at least an order of magnitude better than the Voigt profile with all fitted parameters being linear with pressure. In the most cases pCqSDHCP can reproduce the reference spectra down to 0.2% or better, which fulfills the requirements of the most demanding remote-sensing applications. An important advantage of pCqSDHCP is that a fast algorithm for its computation was developedab4,5 and allows

  13. Zur Frühgeschichte des Thematischen Verzeichnisses. Ludwig Ritter von Köchels „wissenschaftliche" Systematisierung

    Directory of Open Access Journals (Sweden)

    Hochradner, Thomas

    2004-12-01

    Full Text Available In the 19th century - starting with Ludwig Ritter von Kochel's Chronologisch-thematisches Verzeichniss sämmtlicher Tonwerke Wolfgang Amade Mozart's - philologically elaborated Thematic Catalogues completed the inventory of music as well as publisher's- and auction catalogues as a third category of specification of a musical repertoire. Köchel's procedure has been considered as pioneer work in the introduction of a fundamental and very specific kind of text. However, the principle of classification for his systematics put at the beginning is - typical for his approach in general - on the one hand based upon handwritten catalogues of Mozart's work and on the other hand influenced by the conventions of the previously edited extended publisher's catalogues of the works of Ludwig van Beethoven and Felix Mendelssohn Bartholdy at Breitkopf & Härtel's, Leipzig. Thus Köchel's work must be regarded as a strategy following up tendencies of his time that - despite the respect it deserves due to its completeness and accuracy - appears as an almost accidental basis.

    [de] Zu Musikinventaren und Verlags- bzw. Auktionskatalogen treten im 19. Jahrhundert, beginnend mit dem Chronologischthematischen Verzeichniss sämmtlicher Tonwerke Wolfgang Amade Mozart's durch Ludwig Ritter von Köchel, philologisch erarbeitete Thematische Werkverzeichnisse als eine dritte Kategorie des musikalischen Repertoireverzeichnisses hinzu. Köchels Vorgangsweise wird als Pionierleistung einer grundlegenden und fachspezifischen Textsorte gesehen. Das Einteilungsprinzip seiner vorangestellten Systematik fußt jedoch - wie grundsätzlich sein Vorgehen - einesteils auf handschriftlichen Werkverzeichnissen zu Mozarts Schaffen, andemteils in Konventionen der kurz zuvor bei Breitkopf & Härtel in Leipzig aufgelegten, im Vergleich zu früher stark ausgeweiteten Verlagskataloge zu Ludwig van Beethoven und Felix Mendelssohn Bartholdy. So besehen erweist sich K

  14. The intensity calculation of the gas absorption line by multi-line Voigt fitting

    Institute of Scientific and Technical Information of China (English)

    ZHOU Meng-ran; LI Zhen-bi; ZHONG Ming-yu; HE Gang

    2008-01-01

    Adopted the distribution feedback type (DFB) laser to measure the coal mine gas methane, according to the methane located 1.6 lain nearby 2v3 with a R9 direct ab-sorption spectrum, attraction wire intensity of each line was calculated through the multi-line Voigt fitting. The experimental result indicates that in the obtained four attraction recover of wire, the maximum deviation is 2.7%, and the minimum deviation is 0.02%, other results are all in experimental error scope. This research method may apply in the spectrum survey methane gas density, it has characteristics including high precision, strong selectivity, fast response and so on.

  15. Fractional Generalizations of Maxwell and Kelvin-Voigt Models for Biopolymer Characterization.

    Directory of Open Access Journals (Sweden)

    Bertrand Jóźwiak

    Full Text Available The paper proposes a fractional generalization of the Maxwell and Kelvin-Voigt rheological models for a description of dynamic behavior of biopolymer materials. It was found that the rheological models of Maxwell-type do not work in the case of modeling of viscoelastic solids, and the model which significantly better describes the nature of changes in rheological properties of such media is the modified fractional Kelvin-Voigt model with two built-in springpots (MFKVM2. The proposed model was used to describe the experimental data from the oscillatory and creep tests of 3% (w/v kuzu starch pastes, and to determine the values of their rheological parameters as a function of pasting time. These parameters provide a lot of additional information about structure and viscoelastic properties of the medium in comparison to the classical analysis of dynamic curves G' and G" and shear creep compliance J(t. It allowed for a comprehensive description of a wide range of properties of kuzu starch pastes, depending on the conditions of pasting process.

  16. Self-truncation and scaling in Euler-Voigt-α and related fluid models.

    Science.gov (United States)

    Di Molfetta, Giuseppe; Krstlulovic, Giorgio; Brachet, Marc

    2015-07-01

    A generalization of the 3D Euler-Voigt-α model is obtained by introducing derivatives of arbitrary order β (instead of 2) in the Helmholtz operator. The β→∞ limit is shown to correspond to Galerkin truncation of the Euler equation. Direct numerical simulations (DNS) of the model are performed with resolutions up to 2048(3) and Taylor-Green initial data. DNS performed at large β demonstrate that this simple classical hydrodynamical model presents a self-truncation behavior, similar to that previously observed for the Gross-Pitaeveskii equation in Krstulovic and Brachet [Phys. Rev. Lett. 106, 115303 (2011)]. The self-truncation regime of the generalized model is shown to reproduce the behavior of the truncated Euler equation demonstrated in Cichowlas et al. [Phys. Rev. Lett. 95, 264502 (2005)]. The long-time growth of the self-truncation wave number k(st) appears to be self-similar. Two related α-Voigt versions of the eddy-damped quasinormal Markovian model and the Leith model are introduced. These simplified theoretical models are shown to reasonably reproduce intermediate time DNS results. The values of the self-similar exponents of these models are found analytically.

  17. The implementation of non-Voigt line profiles in the HITRAN database: H2 case study

    Science.gov (United States)

    Wcisło, P.; Gordon, I. E.; Tran, H.; Tan, Y.; Hu, S.-M.; Campargue, A.; Kassi, S.; Romanini, D.; Hill, C.; Kochanov, R. V.; Rothman, L. S.

    2016-07-01

    Experimental capabilities of molecular spectroscopy and its applications nowadays require a sub-percent or even sub-per mille accuracy of the representation of the shapes of molecular transitions. This implies the necessity of using more advanced line-shape models which are characterized by many more parameters than a simple Voigt profile. It is a great challenge for modern molecular spectral databases to store and maintain the extended set of line-shape parameters as well as their temperature dependences. It is even more challenging to reliably retrieve these parameters from experimental spectra over a large range of pressures and temperatures. In this paper we address this problem starting from the case of the H2 molecule for which the non-Voigt line-shape effects are exceptionally pronounced. For this purpose we reanalyzed the experimental data reported in the literature. In particular, we performed detailed line-shape analysis of high-quality spectra obtained with cavity-enhanced techniques. We also report the first high-quality cavity-enhanced measurement of the H2 fundamental vibrational mode. We develop a correction to the Hartmann-Tran profile (HTP) which adjusts the HTP to the particular model of the velocity-changing collisions. This allows the measured spectra to be better represented over a wide range of pressures. The problem of storing the HTP parameters in the HITRAN database together with their temperature dependences is also discussed.

  18. An efficient and convenient synthesis of N-substituted amides under heterogeneous condition using Al(HSO4)3 via Ritter reaction

    Indian Academy of Sciences (India)

    Elnaz Karimian; Batool Akhlaghinia; Sara S E Ghodsinia

    2016-03-01

    An efficient and inexpensive synthesis of N-substituted amides from the reaction of aliphatic and aromatic nitriles with various benzylic alcohols (secondary and tertiary) and tert-butyl alcohol by refluxing nitromethane via the Ritter reaction catalyzed by aluminum hydrogen sulfate [Al(HSO4)3] is described. Thecatalyst which is an air-stable, cost-effective solid acid could be readily recycled by filtration and reused four times without any significant loss of its activity.

  19. A high-field pulsed magnet system for x-ray scattering studies in Voigt geometry

    CERN Document Server

    Islam, Zahirul; Ruff, Jacob P C; Das, Ritesh K; Trakhtenberg, Emil; Nojiri, Hiroyuki; Narumi, Yasuo; Canfield, Paul C

    2011-01-01

    We present a new pulsed-magnet system that enables x-ray single-crystal diffraction in addition to powder and spectroscopic studies in Voigt geometry. The apparatus consists of a large-bore solenoid, cooled by liquid nitrogen. A second independent closed-cycle cryostat is used for cooling samples near liquid helium temperatures. Pulsed magnetic fields up to ~30 T with a minimum of ~6 ms in total duration are generated by discharging a 40 kJ capacitor bank into the magnet coil. The unique characteristic of this instrument is the preservation of maximum scattering angle (~23.6 deg.) through the magnet bore by virtue of a novel double-funnel insert. This instrument would facilitate x-ray diffraction and spectroscopic studies that are impractical, if not impossible, to perform using conventional split-pair magnets and offers a practical solution for preserving optical access in future higher-field pulsed magnets.

  20. Generalized Continuum: from Voigt to the Modeling of Quasi-Brittle Materials

    Directory of Open Access Journals (Sweden)

    Jamile Salim Fuina

    2010-12-01

    Full Text Available This article discusses the use of the generalized continuum theories to incorporate the effects of the microstructure in the nonlinear finite element analysis of quasi-brittle materials and, thus, to solve mesh dependency problems. A description of the problem called numerically induced strain localization, often found in Finite Element Method material non-linear analysis, is presented. A brief historic about the Generalized Continuum Mechanics based models is presented, since the initial work of Voigt (1887 until the more recent studies. By analyzing these models, it is observed that the Cosserat and microstretch approaches are particular cases of a general formulation that describes the micromorphic continuum. After reporting attempts to incorporate the material microstructure in Classical Continuum Mechanics based models, the article shows the recent tendency of doing it according to assumptions of the Generalized Continuum Mechanics. Finally, it presents numerical results which enable to characterize this tendency as a promising way to solve the problem.

  1. The intensity calculation of the gas absorption line by multi-line Voigt fitting

    Institute of Scientific and Technical Information of China (English)

    ZHOU Meng-ran; LI Zhen-bi; ZHONG Ming-yu; HE Gang

    2008-01-01

    Adopted the distribution feedback type (DFB) laser to measure the coal minegas methane,according to the methane located 1.6 pm nearby 2 v3 with a R9 direct ab-sorption spectrum,attraction wire intensity of each line was calculated through the multi-line Voigt fitting.The experimental result indicates that in the obtained four attraction recover of wire,the maximum deviation is 2.7%,and the minimum deviation is 0.02%,other results are all in experimental error scope.This research method may apply in the spectrum survey methane gas density,it has characteristics including high precision,strong selectivity,fast response and so on.

  2. On the sensitivity of directions which support Voigt wave propagation in infiltrated biaxial dielectric materials

    CERN Document Server

    Mackay, Tom G

    2013-01-01

    Voigt wave propagation (VWP) was considered in a porous biaxial dielectric material which was infiltrated with a material of refractive index $n_a$. The infiltrated material was regarded as a homogenized composite material in the long-wavelength regime and its constitutive parameters were estimated using the extended Bruggeman homogenization formalism. In our numerical studies, the directions which support VWP were found to vary by as much as $300^\\circ$ per RIU as the refractive index $n_a$ was varied. The sensitivities achieved were acutely dependent upon the refractive index $n_a$ and the degrees of anisotropy and dissipation of the porous biaxial material. The orientations, shapes and sizes of the particles which constitute the infiltrating material and the porous biaxial material exerted only a secondary influence on the maximum sensitivities achieved. Also, for the parameter ranges considered, the degree of porosity of the biaxial material had little effect on the maximum sensitivities achieved. These n...

  3. Lack of exponential stability to Timoshenko system with viscoelastic Kelvin-Voigt type

    Science.gov (United States)

    Malacarne, Andréia; Muñoz Rivera, Jaime Edilberto

    2016-06-01

    We study the Timoshenko systems with a viscoelastic dissipative mechanism of Kelvin-Voigt type. We prove that the model is analytical if and only if the viscoelastic damping is present in both the shear stress and the bending moment. Otherwise, the corresponding semigroup is not exponentially stable no matter the choice of the coefficients. This result is different to all others related to Timoshenko model with partial dissipation, which establish that the system is exponentially stable if and only if the wave speeds are equal. Finally, we show that the solution decays polynomially to zero as {t^{-1/2}} , no matter where the viscoelastic mechanism is effective and that the rate is optimal whenever the initial data are taken on the domain of the infinitesimal operator.

  4. Casimir force between two parallel semiconductor slabs: Magnetic field effects in the Voigt geometry

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Serrano, R.; Palomino-Ovando, M. [Facultad de Ciencias Fisico-Matematicas, Universidad Autonoma de Puebla, Puebla (Mexico); Martinez, G.; Hernandez, P.H.; Cocoletzi, Gregorio H. [Instituto de Fisica, Universidad Autonoma de Puebla, Puebla (Mexico)

    2009-06-15

    We investigate the Casimir force F between two parallel semiconductor slabs taking into account magnetoplasmon effects. For our calculations we consider an external magnetic field applied in the Voigt geometry. Studies are carried out using the formula of F, which is written in terms of the reflectivities of the incident electromagnetic (EM) waves onto the surfaces of the semiconductor slabs, in the vacuum gap between slabs. Results show that the Casimir force depends strongly on the slab thickness as well as on the magnetic-field strength (or equivalently on the cyclotron frequency). At a constant cyclotron frequency and for small slab thickness F/F{sub 0} (F{sub 0} is the ideal force) displays a dip at small separation distances L between slabs. F/F{sub 0} increases with L up to saturation as the slab thickness increases. The curve with the strongest value of F/F{sub 0} corresponds to the semi-infinite medium geometry. For a constant slab thickness and small cyclotron frequency, F/F{sub 0} as a function of L shows a monotonic increase as L increases, and eventually reaches saturation. At high cyclotron frequency F/F{sub 0} displays a dip. The curve of F/F{sub 0} with no applied external field corresponds to the one with the strongest Casimir force. Therefore, magnetoplasmon effects, with an applied magnetic field in the Voigt geometry may inhibit the Casimir force. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. Assessing composition and structure of soft biphasic media from Kelvin-Voigt fractional derivative model parameters

    Science.gov (United States)

    Zhang, Hongmei; Wang, Yue; Fatemi, Mostafa; Insana, Michael F.

    2017-03-01

    Kelvin-Voigt fractional derivative (KVFD) model parameters have been used to describe viscoelastic properties of soft tissues. However, translating model parameters into a concise set of intrinsic mechanical properties related to tissue composition and structure remains challenging. This paper begins by exploring these relationships using a biphasic emulsion materials with known composition. Mechanical properties are measured by analyzing data from two indentation techniques—ramp-stress relaxation and load-unload hysteresis tests. Material composition is predictably correlated with viscoelastic model parameters. Model parameters estimated from the tests reveal that elastic modulus E 0 closely approximates the shear modulus for pure gelatin. Fractional-order parameter α and time constant τ vary monotonically with the volume fraction of the material’s fluid component. α characterizes medium fluidity and the rate of energy dissipation, and τ is a viscous time constant. Numerical simulations suggest that the viscous coefficient η is proportional to the energy lost during quasi-static force-displacement cycles, E A . The slope of E A versus η is determined by α and the applied indentation ramp time T r. Experimental measurements from phantom and ex vivo liver data show close agreement with theoretical predictions of the η -{{E}A} relation. The relative error is less than 20% for emulsions 22% for liver. We find that KVFD model parameters form a concise features space for biphasic medium characterization that described time-varying mechanical properties. The experimental work was carried out at the Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. Methodological development, including numerical simulation and all data analysis, were carried out at the school of Life Science and Technology, Xi’an JiaoTong University, 710049, China.

  6. BPW:靠服务赢得市场——访BPW售后服务总监Stefan Oelhafen和客户服务经理Hartmut Kraus%Good Service Earned Market——Interviewed With Stefan Oelhafen, After-sales Manager and Harmut Krau, Costumer Service Manager

    Institute of Scientific and Technical Information of China (English)

    宁文祥

    2010-01-01

    @@ 德国BPW公司拥有超过百年的历史,是世界上最大的车轴生产厂家之一.服务一直是BPW最看中的环节.借这次德国汉诺威商用车展之机,该公司的售后服务总监Stefan Oelhafen和客户服务经理Hartmut Kraus接受了德国KFZ-Anzeiger杂志的采访.

  7. Suitable weak solutions to the 3D Navier-Stokes equations are constructed with the Voigt approximation

    Science.gov (United States)

    Berselli, Luigi C.; Spirito, Stefano

    2017-03-01

    In this paper we consider the Navier-Stokes equations supplemented with either the Dirichlet or vorticity-based Navier slip boundary conditions. We prove that weak solutions obtained as limits of solutions of the Navier-Stokes-Voigt model satisfy the local energy inequality, and we also prove certain regularity results for the pressure. Moreover, in the periodic setting we prove that if the parameters are chosen in an appropriate way, then we can construct suitable weak solutions through a Fourier-Galerkin finite-dimensional approximation in the space variables.

  8. Investigation of Peak Separation for X-ray Diffraction Profiles of Spinodal Decomposition by a Kind of Optimized Voigt Function

    Institute of Scientific and Technical Information of China (English)

    Liuding WANG; Junqiang ZHOU; Quanxi CAO; Zhao CHEN

    2003-01-01

    The intensity and position of sidebands (satellites) on both sides of main diffraction peak in a great number of X-ray diffraction profiles of alloys always change with progress of aging. The sidebands position is determined by a newly optimized Voigt function in present investigation. Furthermore, for Cu-4 wt pct Ti alloy aged at 400℃ for 720 min and 1080 min, after introducing the weight factor of above two satellites intensity, the relative error between the fitting curves and X-ray diffraction profiles is less than 0.185%, which is more precise than the previously calculating result.

  9. Broadening of the Spectral Atomic Lines Analysis in High Density Argon Corona Plasma by Using Voigt Profile

    Science.gov (United States)

    Nur, M.; Bonifaci, N.; Denat, A.; Atrazhev, V. M.

    2015-06-01

    Studies of spectrum emission from high density argon plasma corona has been done. The analysis of the boardening of spectral atomic lines of Ar-I profile has been curried out by using an empirical approximation based on a Voigt profile. Full-width at half-maximum (FWHM) of the spectral-lines of 763.5 nm has been determined from atmospheric pressure until liquid state. The study liquid argon was curried out in a variation of temperature from K to 151.2 K and hydrostatics pressure from 2.1 MPa to 6.4 MPa. These pressure gives the densities N∞ (i.e. density very far from ionization zone) a variation from 1.08 1022 to 2.11 1022 cm-3. FWHM of Voigt approximation (Wv) of the line 763,5 nm of 'Ar I for: the emission lamp very low pressure (Wv = 0,160 nm) and our corona discharge at a pressure of MPa (Wv = 0,67 nm) and at a pressure of 9,5 MPa (Wv = 1,16 nm). In gas, corona plasma has been generated from 0.1 MPa to 9.5 MPa. We found that the broadening spectral line increase by increasing densities both for. the spectral-lines of 763.5 nm and 696.5 nm. We concluded that broadening of spectrum cause of Van der Waals force.

  10. Voigt transformations in retrospect: missed opportunities? One more essay on the Einstein-Poincar\\'e priority dispute

    CERN Document Server

    Chashchina, Olga; Silagadze, Zurab

    2016-01-01

    Perception of the world by human beings, and of scientific papers in particular, depends on everybody's background shaped by historical circumstances. As put in words by English poet William Blake, in his idiosyncratic and provocative form, "A fool sees not the same tree as the wise man sees". Scientific knowledge is progressing continuously. Therefore, it is not surprising that reading today a paper written more than a hundred years ago, we can extract much more of it than was actually thought or dreamed by the author himself. We demonstrate this on the example of Woldemar Voigt's 1887 paper. From the modern perspective, it may appear that this paper opens a way to both the special relativity and to its anisotropic Finslerian generalization which came into the focus only recently, in relation with the Cohen and Glashow's very special relativity proposal. With some imagination, one can connect Voigt's paper to the notorious Einstein-Poincar\\'e priority dispute, which we comment in light of the above mentioned...

  11. VoIgt profile Parameter Estimation Routine (VIPER): H I photoionization rate at z<0.5

    CERN Document Server

    Gaikwad, Prakash; Choudhury, Tirthankar Roy; Khaire, Vikram

    2016-01-01

    We have developed a parallel code called "VoIgt profile Parameter Estimation Routine (VIPER)" for automatically fitting the H I Ly-$\\alpha$ forest seen in the spectra of QSOs. We obtained the H I column density distribution function (CDDF) and line width ($b$) parameter distribution for $z < 0.45$ using spectra of 82 QSOs obtained using Cosmic Origins Spectrograph and VIPER. Consistency of these with the existing measurements in the literature validate our code. By comparing this CDDF with those obtained from hydrodynamical simulation, we constrain the H I photoionization rate ($\\Gamma_{\\rm HI}$) at $z < 0.45$ in four redshift bins. The VIPER, together with the Code for Ionization and Temperature Evolution (CITE) we have developed for GADGET-2, allows us to explore parameter space and perform $\\chi^2$ minimization to obtain $\\Gamma_{\\rm HI}$. We notice that the $b$ parameters from the simulations are smaller than what are derived from the observations. We show the observed $b$ parameter distribution and...

  12. Unsteady Unidirectional Flow of Voigt Fluid through the Parallel Microgap Plates with Wall Slip and Given Inlet Volume Flow Rate Variations

    OpenAIRE

    Yinwei Lin; Chen, C. K.

    2015-01-01

    In order to solve the velocity profile and pressure gradient of the unsteady unidirectional slip flow of Voigt fluid, Laplace transform method is adopted in this research. Between the parallel microgap plates, the flow motion is induced by a prescribed arbitrary inlet volume flow rate which varies with time. The velocity slip condition on the wall and the flow conditions are known. In this paper, two basic flow situations are solved, which are a suddenly started and a constant acc...

  13. A Computational Investigation of the Finite-Time Blow-Up of the 3D Incompressible Euler Equations Based on the Voigt Regularization

    CERN Document Server

    Larios, Adam; Titi, Edriss S; Wingate, Beth

    2015-01-01

    We report the results of a computational investigation of two recently proved blow-up criteria for the 3D incompressible Euler equations. These criteria are based on an inviscid regularization of the Euler equations known as the 3D Euler-Voigt equations. The latter are known to be globally well-posed. Moreover, simulations of the 3D Euler-Voigt equations also require less resolution than simulations of the 3D Euler equations for fixed values of the regularization parameter $\\alpha>0$. Therefore, the new blow-up criteria allow one to gain information about possible singularity formation in the 3D Euler equations indirectly; namely, by simulating the better-behaved 3D Euler-Voigt equations. The new criteria are only known to be sufficient criteria for blow-up. Therefore, to test the robustness of the inviscid-regularization approach, we also investigate analogous criteria for blow-up of the 1D Burgers equation, where blow-up is well-known to occur.

  14. A new peak detection algorithm for MALDI mass spectrometry data based on a modified Asymmetric Pseudo-Voigt model

    Science.gov (United States)

    2015-01-01

    Background Mass Spectrometry (MS) is a ubiquitous analytical tool in biological research and is used to measure the mass-to-charge ratio of bio-molecules. Peak detection is the essential first step in MS data analysis. Precise estimation of peak parameters such as peak summit location and peak area are critical to identify underlying bio-molecules and to estimate their abundances accurately. We propose a new method to detect and quantify peaks in mass spectra. It uses dual-tree complex wavelet transformation along with Stein's unbiased risk estimator for spectra smoothing. Then, a new method, based on the modified Asymmetric Pseudo-Voigt (mAPV) model and hierarchical particle swarm optimization, is used for peak parameter estimation. Results Using simulated data, we demonstrated the benefit of using the mAPV model over Gaussian, Lorentz and Bi-Gaussian functions for MS peak modelling. The proposed mAPV model achieved the best fitting accuracy for asymmetric peaks, with lower percentage errors in peak summit location estimation, which were 0.17% to 4.46% less than that of the other models. It also outperformed the other models in peak area estimation, delivering lower percentage errors, which were about 0.7% less than its closest competitor - the Bi-Gaussian model. In addition, using data generated from a MALDI-TOF computer model, we showed that the proposed overall algorithm outperformed the existing methods mainly in terms of sensitivity. It achieved a sensitivity of 85%, compared to 77% and 71% of the two benchmark algorithms, continuous wavelet transformation based method and Cromwell respectively. Conclusions The proposed algorithm is particularly useful for peak detection and parameter estimation in MS data with overlapping peak distributions and asymmetric peaks. The algorithm is implemented using MATLAB and the source code is freely available at http://mapv.sourceforge.net. PMID:26680279

  15. Multispectral Fitting Validation of the Speed Dependent Voigt Profile at up to 1300K in Water Vapor with a Dual Frequency Comb Spectrometer

    Science.gov (United States)

    Schroeder, Paul James; Cich, Matthew J.; Yang, Jinyu; Drouin, Brian; Rieker, Greg B.

    2017-06-01

    Using broadband, high resolution dual frequency comb spectroscopy, we test the power law temperature scaling relationship with Voigt, Rautian, and quadratic speed dependent Voigt profiles over a temperature range of 296-1300K for pure water vapor. The instrument covers the spectral range from 6800 cm^{-1} to 7200 cm^{-1} and samples the (101)-(000), (200)-(000), (021)-(000), (111)-(010), (210)-(010), and (031)-(010) vibrational bands of water. The data is sampled with a point spacing of 0.0033 cm^{-1} and absolute frequency accuracy of coal gasifiers and other high temperature systems. In order to extract water concentration and temperature, an extended range of lineshape parameters are needed. Lineshape parameters for pure and argon broadened water are obtained for 278 transitions using the multispectral fitting program Labfit, including self-broadening coefficients, power law temperature scaling exponents, and speed dependence coefficients. The extended temperature range of the data provides valuable insight into the application of the speed-dependence corrections of the line profiles, which are shown to have more reasonable line broadening temperature dependencies.

  16. Synthesis of novel amide functionalized 2H-chromene derivatives by Ritter amidation of primary alcohol using HBF4·OEt2 as a mild and versatile reagent and evaluation of their antimicrobial and anti-biofilm activities.

    Science.gov (United States)

    Ratnakar Reddy, K; Poornachandra, Y; Jitender Dev, G; Mallareddy, G; Nanubolu, Jagadeesh B; Kumar, C Ganesh; Narsaiah, B

    2015-08-01

    A series of novel amide functionalized 2H-chromene derivatives 3 were prepared starting from ethyl-2-hydroxy-2-(trifluoromethyl)-2H-chromene-3-carboxylate 1 via sodium borohydride reduction followed by Ritter amidation using HBF4·OEt2 as a mild and versatile reagent. All the products 3 were screened for antimicrobial activity against various Gram-positive, Gram-negative bacteria and fungal strain. The promising derivatives such as 3f, 3g, 3k, 3l, 3m, 3n and 3o were further screened for minimum bactericidal concentration and bio-film inhibition activity and identified the potential ones. Among all the promising, compound 3g was more potent for antimicrobial, MBC and anti bio-film activities. The structure verses activity relationship of 3g revealed that the presence of two bromine atoms at sixth and R position promotes high activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. [Reiner Nürnberg, Ekkehard Höxtermann, Martina Voigt. Elisabeth Schiemann 1881-1972. Vom AußBruch der Genetik und der Frauen in den UmBrüchen des 20. Jahrhunderts] / Monika von Hirschheydt

    Index Scriptorium Estoniae

    Hirschheydt, Monika von

    2015-01-01

    Arvustus: Nürnberg, Reiner, Höxtermann, Ekkehard, Voigt, Martina. Elisabeth Schiemann 1881-1972. Vom AußBruch der Genetik und der Frauen in den UmBrüchen des 20. Jahrhunderts. Beiträge eines Symposiums zum 200. Gründungsjubiläum der Humboldt-Universität Berlin. Rangsdorf: Basilisken-Presse 2014

  18. [Reiner Nürnberg, Ekkehard Höxtermann, Martina Voigt. Elisabeth Schiemann 1881-1972. Vom AußBruch der Genetik und der Frauen in den UmBrüchen des 20. Jahrhunderts] / Monika von Hirschheydt

    Index Scriptorium Estoniae

    Hirschheydt, Monika von

    2015-01-01

    Arvustus: Nürnberg, Reiner, Höxtermann, Ekkehard, Voigt, Martina. Elisabeth Schiemann 1881-1972. Vom AußBruch der Genetik und der Frauen in den UmBrüchen des 20. Jahrhunderts. Beiträge eines Symposiums zum 200. Gründungsjubiläum der Humboldt-Universität Berlin. Rangsdorf: Basilisken-Presse 2014

  19. Influence of yielding base and rigid base on propagation of Rayleigh-type wave in a viscoelastic layer of Voigt type

    Indian Academy of Sciences (India)

    S SAHA; A CHATTOPADHYAY; K C MISTRI; A K SINGH

    2017-09-01

    The present study aims to study the propagation of Rayleigh-type wave in a layer, composed of isotropic viscoelastic material of Voigt type, with the effect of yielding base and rigid base in two distinct cases.With the aid of an analytical treatment, closed-form expressions of phase velocity and damped velocity for both the cases are deduced. As a special case of the problem it is found that obtained results are in good agreement with the established standard results existing in the literature. It is established through the study that volume viscoelastic and shear-viscoelastic material parameter and yielding parameter have significant effect on phaseand damped velocities of Rayleigh-type wave in both the cases. Numerical calculations and graphical illustration have been carried out for both the considered cases in the presence and the absence of viscoelasticity. Acomparative study has been performed to analyse the effect of layer with yielding base, traction-free base and rigid base on the phase and damped velocities of Rayleigh-type wave.

  20. Stravinsky: The Rite of Spring / Hartmut, Lück

    Index Scriptorium Estoniae

    Lück, Hartmut

    1996-01-01

    Uuest heliplaadist "Stravinsky: The Rite of Spring. Canticum Sacrum. Requiem Canticles. Choral Variations on "Vom Himmel hoch". Lausanne Pro Arte Choir, Suisse Romande Chamber Choir and Orchestra, Neeme Järvi. Chandos CHAN 9408 (75 minutes:DDD)

  1. Stravinsky: The Rite of Spring / Hartmut, Lück

    Index Scriptorium Estoniae

    Lück, Hartmut

    1996-01-01

    Uuest heliplaadist "Stravinsky: The Rite of Spring. Canticum Sacrum. Requiem Canticles. Choral Variations on "Vom Himmel hoch". Lausanne Pro Arte Choir, Suisse Romande Chamber Choir and Orchestra, Neeme Järvi. Chandos CHAN 9408 (75 minutes:DDD)

  2. The properties of the extraordinary mode and surface plasmon modes in the three-dimensional magnetized plasma photonic crystals based on the magneto-optical Voigt effects

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hai-Feng, E-mail: hanlor@163.com, E-mail: lsb@nuaa.edu.cn [Key Laboratory of Radar Imaging and Microwave Photonics (Nanjing Univ. Aeronaut. Astronaut.), Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Nanjing Artillery Academy, Nanjing 211132 (China); Liu, Shao-Bin, E-mail: hanlor@163.com, E-mail: lsb@nuaa.edu.cn; Tang, Yi-Jun [Key Laboratory of Radar Imaging and Microwave Photonics (Nanjing Univ. Aeronaut. Astronaut.), Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

    2014-06-15

    In this paper, the properties of the extraordinary mode and surface plasmon modes in the three-dimensional (3D) magnetized plasma photonic crystals (MPPCs) with face-centered-cubic lattices that are composed of the core tellurium (Te) spheres with surrounded by the homogeneous magnetized plasma shells inserted in the air, are theoretically investigated in detail by the plane wave expansion method, as the magneto-optical Voigt effects of magnetized plasma are considered (the incidence electromagnetic wave vector is perpendicular to the external magnetic field at any time). The optical switching or wavelength division multiplexer can be realized by the proposed 3D MPPCs. Our analyses demonstrate that the complete photonic band gaps (PBGs) and two flatbands regions for the extraordinary mode can be observed obviously. PBGs can be tuned by the radius of core Te sphere, the plasma density and the external magnetic field. The flatbands regions are determined by the existence of surface plasmon modes. Numerical simulations also show that if the thickness of magnetized plasma shell is larger than a threshold value, the band structures of the extraordinary mode will be similar to those obtained from the same structure containing the pure magnetized plasma spheres. In this case, the band structures also will not be affected by the inserted core spheres. It is also provided that the upper edges of two flatbands regions will not depend on the topology of lattice. However, the frequencies of lower edges of two flatbands regions will be convergent to the different constants for different lattices, as the thickness of magnetized plasma shell is close to zero.

  3. (--SCLAREOL CONVERSION IN RITTER'S REACTION CONDITIONS

    Directory of Open Access Journals (Sweden)

    S. Kovalskaya

    2012-12-01

    Full Text Available The main products of sclareol (1 Ritter’s reaction in mild conditions are (8R,13R-Labd-14(15-en-8,13-diacetamide (2 (8R,13S-Labd-14(15-en-8,13-diacetamide (3 stereoisomeric on C13 atom and having unrearranged native diol skeleton. We present in the current communication the results of sclareol converting (1 into nitrogen-containing labdanes in the Ritter’s reaction conditions.

  4. Intervention of phenonium ion in Ritter reactions.

    Science.gov (United States)

    Ho, Tse-Lok; Chein, Rong-Jie

    2004-01-23

    The transformation of phenylethyl chloride to 3,4-dihydroisoquinolines is shown to proceed via phenonium ion. The evidence comes from a study of dideuterated analogue 4, and the monomethylated and dimethylated compounds 2 and 3.

  5. Cultivation of the Hairy Roots of Trichosanthes Bracteata Voigt in the Photobioreactor%大苞栝楼发根在光辐射发根反应器中的培养

    Institute of Scientific and Technical Information of China (English)

    徐明芳; 黄伟建; 葛湘峰; 陈心满

    2004-01-01

    利用农杆菌(Agrobacterium rhizogenes)R1601诱导药用植物大苞栝楼(Trichosanthes bracteata Voigt)外植体无菌苗发根,建立毛状根生物反应器培养系统.分析了光照强度、溶氧饱和强度及碳源等外界影响因子对反应器中发根生长的作用.结果表明:在光照强度为25W/m2、、溶氧饱和强度为80%时,发根的比生长速率与生物量维持在较高的水平;蔗糖对发根生长的促进作用明显优于葡萄糖:在30~40g/L的糖含量范围内,于MS培养基中采用两级添加方式添加蔗糖,发根生物量(9.5g/L)比采用单级添加方式的(7.2g/L)高出20%以上.

  6. Do use the climate policy mechanisms of the Kyoto protocol.. An interview with Hartmut Grass, Hamburg; Innovative Instrumente des Kyoto-Protokolls nutzen.. Interview mit Hartmut Grassl, Hamburg

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1999-12-01

    The aspects discussed in this interview are of a global and national nature. The global aspects relate to the results of the UN conference in Kyoto in matters of the UN Framework Convention on Climate Change, and the national aspects relate to Germany's environmental and energy policy and the current situation in the context of global policy for greenhouse gas abatement. (orig./CB) [German] Nach der Anfang November in Bonn zu Ende gegangenen 5. Vertragsstaatenkonferenz zur Klimarahmenkonvention bleiben trotz Bewegung die grossen Fragen fuer die Folgekonferenz im naechsten Jahr in Den Haag vorbehalten. Fehlt der akute Zeitdruck, herrscht inzwischen Entlastung an der Klimafront? Welche Rolle spielen Boeden, Wasser und Waelder im Klimageschehen, welche die Methanemission? Und schliesslich: Wo steht Deutschland und welches Gewicht besitzen die flexiblen Instrumente in einer internationalen Klimapolitik? lauten die Themen des 'et'-Interviews mit Klimaforscher H. Grassl. (orig.)

  7. Symposium on job creation and job destruction in transition countries / John Haltiwanger, Hartmut Lehmann, Katherine Terrell

    Index Scriptorium Estoniae

    Haltiwanger, John

    2003-01-01

    Ülevaade 2002. aasta aprillis Costa Rical toimunud konverentsi Labour Markets in Emerging Economies raames toimunud sümpoosiumist ning sealsetest ettekannetest, milles käsitleti tööjõu voolavusega seotud küsimusi üleminekuriikides

  8. Symposium on job creation and job destruction in transition countries / John Haltiwanger, Hartmut Lehmann, Katherine Terrell

    Index Scriptorium Estoniae

    Haltiwanger, John

    2003-01-01

    Ülevaade 2002. aasta aprillis Costa Rical toimunud konverentsi Labour Markets in Emerging Economies raames toimunud sümpoosiumist ning sealsetest ettekannetest, milles käsitleti tööjõu voolavusega seotud küsimusi üleminekuriikides

  9. Oppolzer, Theodor Egon Ritter von (1841-86)

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    A gifted mathematician, he knew 14 000 logarithms by heart. He calculated the Canon der Finsternisse (Canon of Eclipses) listing the time of occurrence and the visibility track of 8000 solar and 5200 lunar eclipses between 1208 BC and AD 2161, used for historical research....

  10. Algorithm xxx: computing the Faddeyeva and Voigt functions

    CERN Document Server

    Zaghloul, Mofreh R

    2011-01-01

    We present a MATLAB function for the numerical evaluation of the Faddeyeva function w(z). The function is based on a newly developed accurate algorithm. In addition to its higher accuracy, the software provides a flexible accuracy vs efficiency trade-off through a controlling parameter that may be used to reduce accuracy and computational time and vice versa. Verification of the flexibility, reliability and superior accuracy of the algorithm is provided through comparison with standard algorithms available in other libraries and software packages.

  11. Introduction to Voigt's wind power plant. [energy conversion efficiency

    Science.gov (United States)

    Tompkin, J.

    1973-01-01

    The design and operation of a 100 kilowatt wind driven generator are reported. Its high speed three-bladed turbine operates at a height of 50 meters. Blades are rigidly connected to the hub and turbine revolutions change linearly with wind velocity, maintaining a constant speed ratio of blade tip velocity to wind velocity over the full predetermined wind range. Three generators installed in the gondola generate either dc or ac current. Based on local wind conditions, the device has a maximum output of 720 kilowatts at a wind velocity of 16 meters per second. Total electrical capacity is 750 kilowatts, and power output per year is 2,135,000 kilowatt/hours.

  12. Diffusion and wave behaviour in linear Voigt model

    CERN Document Server

    De Angelis, Monica

    2012-01-01

    A boundary value problem related to a third- order parabolic equation with a small parameter is analized. This equation models the one-dimensional evolution of many dissipative media as viscoelastic fluids or solids, viscous gases, superconducting materials, incompressible and electrically conducting fluids. Moreover, the third-order parabolic operator regularizes various non linear second order wave equations. In this paper, the hyperbolic and parabolic behaviour of the solution is estimated by means of slow time and fast time. As consequence, a rigorous asymptotic approximation for the solution is established.

  13. Synthesis of Carbasugars from Aldonolactones: Ritter-Type Epoxide Opening of Polyhydroxylated Aminocyclopentanes

    DEFF Research Database (Denmark)

    Lundt, Inge; Johansen, Steen Karsk; Kornø, Hanne Tøfting

    1999-01-01

    Using the cis-fused cyclopentane-1,4-lactone, 1(R),5(S)-7(R),8(R)-dihydroxy-2-oxabicyclo[3.3.0]oct-3-one (1), as starting material, 5-deoxycarba-*-L-xylo-hexofuranose (6) together with ?- (12) and ?-1-amino-1,5-dideoxycarba-L-xylo-hexofuranose (16) have been prepared using a number...... of stereoselective transformations. The key step was the regioselective opening of the epoxide 1(R),5(S)-7(R),8(R)-epoxy-2-oxabicyclo[3.3.0]oct-3-one (4) with different nucleophiles....

  14. Euroopa integratsioon kirikuloolises perspektiivis / Adolf Martin Ritter ; tõlk. Siret Rutiku

    Index Scriptorium Estoniae

    Ritter, Adolf Martin

    1999-01-01

    Järg Nov/10. Ettekanne on peetud Tartu Ülikooli usuteaduskonnas Eesti-Saksa akadeemilise nädala Academica III raames. Käsitluse aluseks on teesid: Ida ja Lääs, ristiusk, misjonilugu, rahvakirik, oikumeenia, kirikute roll uuenevas Euroopas, usupuhastus, kirikuloo tänapäev

  15. Euroopa integratsioon kirikuloolises perspektiivis / Adolf Martin Ritter ; tõlk. Siret Rutiku

    Index Scriptorium Estoniae

    Ritter, Adolf Martin

    1999-01-01

    Järg Nov/10. Ettekanne on peetud Tartu Ülikooli usuteaduskonnas Eesti-Saksa akadeemilise nädala Academica III raames. Käsitluse aluseks on teesid: Ida ja Lääs, ristiusk, misjonilugu, rahvakirik, oikumeenia, kirikute roll uuenevas Euroopas, usupuhastus, kirikuloo tänapäev

  16. Synthesis of (Arylamido)pyrrolidinone Libraries through Ritter-Type Cascade Reactions of Dihydroxylactams

    DEFF Research Database (Denmark)

    Wu, Peng; Petersen, Michael Åxman; Petersen, Rico

    2015-01-01

    diastereoselectivity. A combined one-step Ritter–hydrolysis procedure proved to be of equal efficiency. This versatile method, which was successfully used for the construction of a screening library containing 706 molecules within the European Lead Factory consortium, provides a simple way to access new compounds...

  17. Introducing Research Methods to Undergraduate Majors Through an On-Campus Observatory with The University of Toledo's Ritter Observatory

    Science.gov (United States)

    Richardson, Noel; Hardegree-Ullman, Kevin; Bjorkman, Jon Eric; Bjorkman, Karen S.; Ritter Observing Team

    2017-01-01

    With a 1-m telescope on the University of Toledo (OH) main campus, we have initiated a grad student-undergraduate partnership to help teach the undergraduates observational methods and introduce them to research through peer mentorship. For the last 3 years, we have trained up to 21 undergraduates (primarily physics/astronomy majors) in a given academic semester, ranging from freshman to seniors. Various projects are currently being conducted by undergraduate students with guidance from graduate student mentors, including constructing three-color images, observations of transiting exoplanets, and determination of binary star orbits from echelle spectra. This academic year we initiated a large group research project to help students learn about the databases, journal repositories, and online observing tools astronomers use for day-to-day research. We discuss early inclusion in observational astronomy and research of these students and the impact it has on departmental retention, undergraduate involvement, and academic success.

  18. Maastik : Esteetilise funktsioonist modernses ühiskonnas / Joachim Ritter ; tlk. Age Veeroos, saatesõna Ülo Matjus

    Index Scriptorium Estoniae

    Ritter, Joachim

    1996-01-01

    Loodus kui esteetiliselt vahendatud maastik: uusaja maailma kuulub loodus maastikuna, kusjuures luule ja kunst kordavad teaduse kaudu vahendatud 'objektiivset' loodust esteetiliselt. Ka Francesco Petrarca kirjast Francesco Dioginile Borgo San Sepolcrost ja Friedrich Schilleri luuletusest 'Jalutuskäik'

  19. Maastik : Esteetilise funktsioonist modernses ühiskonnas / Joachim Ritter ; tlk. Age Veeroos, saatesõna Ülo Matjus

    Index Scriptorium Estoniae

    Ritter, Joachim

    1996-01-01

    Loodus kui esteetiliselt vahendatud maastik: uusaja maailma kuulub loodus maastikuna, kusjuures luule ja kunst kordavad teaduse kaudu vahendatud 'objektiivset' loodust esteetiliselt. Ka Francesco Petrarca kirjast Francesco Dioginile Borgo San Sepolcrost ja Friedrich Schilleri luuletusest 'Jalutuskäik'

  20. Genetic variability of an unusual apomictic triploid cactus--Haageocereus tenuis Ritter--from the Coast of Central Peru.

    Science.gov (United States)

    Arakaki, Mónica; Speranza, Pablo; Soltis, Pamela S; Soltis, Douglas E

    2013-01-01

    Haageocereus tenuis is a prostrate cactus restricted to a small area of 2 km(2) near the city of Lima, Peru. The species is triploid and propagates mainly through stem fragmentation. In addition, propagation via agamospermy is documented and adventitious embryony is also inferred as a mechanism. Although seedling recruitment has not been observed in nature, we have shown that asexually produced seeds are viable. About 45 adult individuals, plus 9 individuals obtained from seeds, were sampled and 5 microsatellite markers were used to assess genetic variability. Microsatellite analysis confirms that individuals from the only existing population are genetically identical and that the population likely represents a single clone. The absence of mutations in any individual, even in highly variable microsatellite loci, may indicate that the species is also of recent origin. Other prostrate species of Haageocereus are suspected to be occasional apomicts. This phenomenon has significant implications for the evolutionary biology and ecology of Haageocereus and other clonal Cactaceae.

  1. Translating ancient Greek aspect: Sappho's Fr. 1 Voigt / Janika Päll

    Index Scriptorium Estoniae

    Päll, Janika, 1965-

    2007-01-01

    Vana-kreeka keele aspektist, selle kasutamisest ja tõlkimisprobleemidest Sappho luuletuse tõlkeid analüüsides. Lisas toodud ka Sappho luuletus originaalkeeles, tõlked ladina, eesti, inglise, saksa, itaalia, prantsuse ja vene keelde

  2. Remark on "Algorithm 916: Computing the Faddeyeva and Voigt functions": Efficiency Improvements and Fortran Translation

    CERN Document Server

    Zaghloul, Mofreh R

    2015-01-01

    This remark describes efficiency improvements to Algorithm 916 [Zaghloul and Ali 2011]. It is shown that the execution time required by the algorithm, when run at its highest accuracy, may be improved by more than a factor of two. A better accuracy vs efficiency trade off scheme is also implemented; this requires the user to supply the number of significant figures desired in the computed values as an extra input argument to the function. Using this trade-off, it is shown that the efficiency of the algorithm may be further improved significantly while maintaining reasonably accurate and safe results that are free of the pitfalls and complete loss of accuracy seen in other competitive techniques. The current version of the code is provided in Matlab and Scilab in addition to a Fortran translation prepared to meet the needs of real-world problems where very large numbers of function evaluations would require the use of a compiled language. To fulfill this last requirement, a recently proposed reformed version o...

  3. The Physical Conditions of Intermediate Redshift MgII Absorbing Clouds from Voigt Profile Analysis

    CERN Document Server

    Churchill, C W; Charlton, J; Churchill, Chris; Vogt, Steven; Charlton, Jane

    2003-01-01

    [Slightly Abridged] We present a detailed statistical analysis of the column densities, N, and Doppler parameters, b, of MgII absorbing clouds at redshifts 0.4~5 km/s for MgII and FeII and ~7 km/s for MgI. The clouds are consistent with being thermally broadened, with temperatures in the 30-40,000K range. (4) A two-component Gaussian model to the velocity two-point correlation function yielded velocity dispersions of 54 km/s and 166 km/s. The narrow component has roughly twice the amplitude of the broader component. The width and amplitude of the broader component decreases as equivalent width increases. (5) From photoionization models we find that the column density ratios are most consistent with photoionization by the extragalactic background, as opposed to stars. Based upon N(MgI)/N(MgII), it appears that at least two-phase ionization models are required to explain the data.

  4. Translating ancient Greek aspect: Sappho's Fr. 1 Voigt / Janika Päll

    Index Scriptorium Estoniae

    Päll, Janika, 1965-

    2007-01-01

    Vana-kreeka keele aspektist, selle kasutamisest ja tõlkimisprobleemidest Sappho luuletuse tõlkeid analüüsides. Lisas toodud ka Sappho luuletus originaalkeeles, tõlked ladina, eesti, inglise, saksa, itaalia, prantsuse ja vene keelde

  5. SCREENING OF ANTIMICROBIAL, CYTOTOXIC AND PESTICIDAL ACTIVITIES OF COCCINIA GRANDIS (L. VOIGT

    Directory of Open Access Journals (Sweden)

    Md. Faruk Hasan

    2016-06-01

    Full Text Available This study was undertaken to assess the antibacterial, antifungal, cytotoxic and pesticidal activities of Coccinia grandis roots extract. The antimicrobial activity was evaluated using disc diffusion method against some pathogenic microorganisms. Cytotoxicity was determined using brine shrimp lethality bioassay method. The plant extract was screened for pesticidal activity towards Sitophilus oryzae adults. Minimum inhibitory concentration (MIC was also studied against test organisms, using serial dilution technique to determine the antibacterial potency. In antibacterial screening, large inhibition zones were observed against the tested gram-positive (Bacillus subtilis, Sarcina lutea and Stapphylococcus aureus and gram-negative (Salmonella typhi and Shigella dysenteriae bacteria. In antifungal screening, the extract showed moderate antifungal activities against the tested fungi (Candida albicans and Colletotrichum falcatum. In cytotoxicity activity test, LC50 (lethal concentration, 50% of the extract against brine shrimp nauplii was 15.00µg/ml. The plant extract also showed moderate pesticidal activities towards S. oryzae adults. These results suggested that the plant extract has significant antibacterial activity against the tested bacteria, moderate antifungal, cytotoxic and pesticidal activity towards the tested fungi, brine shrimp nauplii and S. oryzae adults, respectively.

  6. Catalogue of the mite families Ascidae Voigts & Oudemans, Blattisociidae Garman and Melicharidae Hirschmann (Acari: Mesostigmata).

    Science.gov (United States)

    Moraes, Gilberto J De; Britto, Erika P J; Mineiro, Jefferson L De C; Halliday, Bruce

    2016-05-19

    Until recently, mites in the families Ascidae, Blattisociidae and Melicharidae together constituted what was considered to be a single family, the Ascidae (sensu lato). We include all three families in this catalogue because of their many morphological similarities, as well as for historic and ecological reasons. Together with most Phytoseiidae and some Ameroseiidae, these are the only mesostigmatid mites commonly found on plants. In this publication we initially provide a historic overview of these groups, summarising the changes in the taxonomic concepts of the genera and other subfamilial taxa. This is followed by a thorough characterisation of each family and genus. A dichotomous key for the separation of families and genera is included. We then list the species considered to belong to these families, with details of the literature concerning the taxonomy of each species, and information about their type specimens and type localities wherever possible. The numbers of taxa considered as valid in this publication are: 372 species in 17 genera of Ascidae, 367 species in 14 genera of Blattisociidae, and 206 species in 11 genera of Melicharidae. We attempt to place each species in the most appropriate genus. In doing so, we propose 30 new combinations, including a species here transferred from Ascidae sensu stricto to Rhodacaridae. We propose five new names to replace junior homonyms, one new generic synonymy, and one new specific synonymy. Some species are insufficiently known and could not be reliably placed in any genus; these are listed as species incertae sedis. We also provide a list of species and genera that have been placed in these families at some time, but which have been transferred to other groups.

  7. Numerical implementation of Voigt and Maxwell models for simulation of waves in the ground

    Directory of Open Access Journals (Sweden)

    Sheshenin Sergey Vladimirovich

    2014-12-01

    Full Text Available A lot of papers have been dedicated to simulation of dynamic processes in soil and underground structures. For example, some authors considered wave distribution in underground water pipes for creation of vibration monitoring system, others considered theoretical and algorithm aspects of efficient implementation of realistic seismic wave attenuation due to viscosity development with the help of Finite Difference Method, etc. The paper describes the numerical simulation, designed for simulation of the stress-strain state in the ground subjected to wave processes. We consider the ground with a concrete structure immersed in. The purpose of the work is the description of small vibrations in hard soil, which can nevertheless make undesirable impact on the objects in the ground or on the surface. Explicit Wilkins type scheme is used for time integration. It has proven to be successful, including the use in a well-known LS-DYNA code. As a result we created our own computer code based on the finite element method (FEM. An example of its practical usage is given.

  8. "Unser Denken ist schlecterdings nur eine Galvanisation..." Om mødet mellem naturvidenskab, digtningsteori og musikæstetik hos Novalis

    DEFF Research Database (Denmark)

    Sørensen, Søren Møller

    2003-01-01

    elektrokemi, mindedrift, musikæstetik, litteraturteori, Novalis, Johann Wilhelm Ritter, Carl Dahlhaus......elektrokemi, mindedrift, musikæstetik, litteraturteori, Novalis, Johann Wilhelm Ritter, Carl Dahlhaus...

  9. Blood Sugar Lowering Effect of Coccinia grandis (L. J. Voigt: Path for a New Drug for Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    M. A. A. K. Munasinghe

    2011-01-01

    Full Text Available Background. Role of herbs in the management and control of diabetes has emerged fast over the years. We assessed the efficacy of Coccinia grandis (locally known as Ken, Kovakka leaves as a hypoglycemic agent. Methods. Double-blind phase I clinical trial was conducted at the general hospital and a private hospital in Matara in August 2009. All the participants were given a common meal for dinner, and they maintained a 10-hour fasting period. Sixty-one healthy volunteers were given a meal containing 20 g of leaves of Coccinia grandis which was mixed with a measured amount of scraped coconut and table salt for breakfast, and other 61 were given the placebo meal which also contained scraped coconut and salt. Glucose tolerance test was performed blindly for the two groups. Mixed factorial design analysis of variance and student's t-test were applied. Results. Overall blood sugar levels of the experimental group were also significantly lower than those of the control group (F(1,117 5.56, <0.05. Increase in the blood sugar levels from fasting to one hour (F(1,117 6.77, <0.05 and two hours (F(1,117 5.28, <0.05 postprandially was statistically significant for participants who were in the control group than those of in the experimental group. The mean difference of postprandial blood sugar levels (mg/dL after one hour (20.2, 95% confidence interval, 4.81 to 35.5 and two hours (11.46, 95% confidence interval; 1.03 to 21.9 was statistically significant between the two groups. Conclusions. Coccinia grandis has a blood sugar lowering effect. However further studies are needed to validate our findings.

  10. A pseudo-Voigt component model for high-resolution recovery of constituent spectra in Raman spectroscopy

    DEFF Research Database (Denmark)

    Alstrøm, Tommy Sonne; Schmidt, Mikkel Nørgaard; Rindzevicius, Tomas

    2017-01-01

    Raman spectroscopy is a well-known analytical technique for identifying and analyzing chemical species. Since Raman scattering is a weak effect, surface-enhanced Raman spectroscopy (SERS) is often employed to amplify the signal. SERS signal surface mapping is a common method for detecting trace...

  11. Der moderne Staat : ein Glanzstück europäischer Form und occidentalen Rationalismus / Rüdiger Voigt

    Index Scriptorium Estoniae

    Voigt, Rüdiger

    2014-01-01

    Modernsest riigist, antiikse riigikunsti taassünnist, erinevatest riigiteooriatest (Machiavelli, Bodin, Hobbes, Locke, Montesquieu, Rousseau, Kant, Hegel, Marx, Jellinek, Weber, Habermas, Foucault, Agamben), globaliseerumise väljakutsetest, ohtudest, riigi tulevikust

  12. Der moderne Staat : ein Glanzstück europäischer Form und occidentalen Rationalismus / Rüdiger Voigt

    Index Scriptorium Estoniae

    Voigt, Rüdiger

    2014-01-01

    Modernsest riigist, antiikse riigikunsti taassünnist, erinevatest riigiteooriatest (Machiavelli, Bodin, Hobbes, Locke, Montesquieu, Rousseau, Kant, Hegel, Marx, Jellinek, Weber, Habermas, Foucault, Agamben), globaliseerumise väljakutsetest, ohtudest, riigi tulevikust

  13. Morphology, anatomy and histology of a new species of Flabellina Voigt, 1834 (Opisthobranchia: Aeolidoidea) from the Chilean coast

    NARCIS (Netherlands)

    Fischer, M.A.; Velde, G. van der; Roubos, E.W.

    2007-01-01

    Flabellina cerverai sp. nov. was found in Bay La Herradura, Coquimbo, North of Chile, and clearly differs from other members of the Flabellinidae by the following combination of main characters: (1) small body size (4.5–6.3 mm), (2) translucent-yellow body coloration, with a white line along the

  14. Morphology, anatomy and histology of a new species of Flabellina Voigt, 1834 (Opisthobranchia: Aeolidoidea) from the Chilean coast

    NARCIS (Netherlands)

    Fischer, M.A.; Velde, G. van der; Roubos, E.W.

    2007-01-01

    Flabellina cerverai sp. nov. was found in Bay La Herradura, Coquimbo, North of Chile, and clearly differs from other members of the Flabellinidae by the following combination of main characters: (1) small body size (4.5–6.3 mm), (2) translucent-yellow body coloration, with a white line along the dor

  15. Voigt modelling of size–strain analysis: Application to -Al2O3 prepared by combustion technique

    Indian Academy of Sciences (India)

    K Santra; P Chatterjee; S P Sen Gupta

    2002-06-01

    A comprehensive analysis of size and strain broadened profile shapes in X-ray diffraction line broadening analysis is presented. Both size and strain broadened profiles were assumed to be Voigtian and the derived microstructural parameters (size and strain) were found to be in close agreement with those calculated from model independent Warren–Averbach method. The method is applied to three different alumina samples viz. micron size -alumina (-Al2O3) prepared by the combustion of aluminium nitrate and urea mixture, annealed samples and commercial -Al2O3 sample. It is likely from the present analysis that a significant Gaussian size contribution is related to narrow size distribution observed from the analysis. It has been concluded that present Voigtian analysis is more reliable and may largely replace the earlier simplified integral breadth methods of analysis often used in line broadening analysis.

  16. A new peak detection algorithm for MALDI mass spectrometry data based on a modified Asymmetric Pseudo-Voigt model

    OpenAIRE

    Wijetunge, Chalini D; Saeed, Isaam; Boughton, Berin A.; Roessner, Ute; Saman K. Halgamuge

    2015-01-01

    Background Mass Spectrometry (MS) is a ubiquitous analytical tool in biological research and is used to measure the mass-to-charge ratio of bio-molecules. Peak detection is the essential first step in MS data analysis. Precise estimation of peak parameters such as peak summit location and peak area are critical to identify underlying bio-molecules and to estimate their abundances accurately. We propose a new method to detect and quantify peaks in mass spectra. It uses dual-tree complex wavele...

  17. Magnetotransmission of unpolarized infrared radiation in Hg1 - x Cd x Cr2Se4 (0 ≤ x ≤ 1) single crystals studied using the voigt geometry

    Science.gov (United States)

    Sukhorukov, Yu. P.; Telegin, A. V.; Bebenin, N. G.; Patrakov, E. I.; Naumov, S. V.; Fedorov, V. A.; Menshchikova, T. K.

    2013-11-01

    The features characterizing the behavior of magnetotransmission in Hg1 - x Cd x Cr2Se4 single crystals are studied using natural light in the infrared spectral range. The relation between the changes in the magneto-optical properties and in the electron band structure is found. It is shown that the most significant changes in the magnetotransmission spectrum and the band structure occur within the 0.1 < x < 0.25 range.

  18. Chromosomal localization of 45S rDNA, sex-specific C values, and heterochromatin distribution in Coccinia grandis (L.) Voigt.

    Science.gov (United States)

    Bhowmick, Biplab Kumar; Yamamoto, Masashi; Jha, Sumita

    2016-01-01

    Coccinia grandis is a widely distributed dioecious cucurbit in India, with heteromorphic sex chromosomes and X-Y sex determination mode. The present study aids in the cytogenetic characterization of four native populations of this plant employing distribution patterns of 45S rDNA on chromosomes and guanine-cytosine (GC)-rich heterochromatin in the genome coupled with flow cytometric determination of genome sizes. Existence of four nucleolar chromosomes could be confirmed by the presence of four telomeric 45S rDNA signals in both male and female plants. All four 45S rDNA sites are rich in heterochromatin evident from the co-localization of telomeric chromomycin A (CMA)(+ve) signals. The size of 45S rDNA signal was found to differ between the homologues of one nucleolar chromosome pair. The distribution of heterochromatin is found to differ among the male and female populations. The average GC-rich heterochromatin content of male and female populations is 23.27 and 29.86 %, respectively. Moreover, the male plants have a genome size of 0.92 pg/2C while the female plants have a size of 0.73 pg/2C, reflecting a huge genomic divergence between the genders. The great variation in genome size is owing to the presence of Y chromosome in the male populations, playing a multifaceted role in sexual divergence in C. grandis.

  19. [Paskal Joseph Ritter von Ferro, the Reformer of the Austrian Public Health. On the occasion of the 200th anniversary of his death in consequence of the battle of Wagram against Napoleon].

    Science.gov (United States)

    Flamm, Heinz

    2009-01-01

    Paskal Joseph Ferro, born on June 5th, 1753 in Bonn, Germany, in the course of his military service as a surgeon graduated medicine in 1777 in Strasbourg and Vienna. Here initially he worked as a private physician in a hospital. In 1785 he became an assistant to the leading municipal physician, in 1793 he was appointed director of the district hospitals and in 1793 medical official in charge of Lower Austria. In 1795 Ferro was the first on the now created position of "Protomedicus" (director of the health administration) of an Austrian country. His most important acts were the creation of the first medical cold water bath in Austria, the foundation of institutions for the salvation of casualties, the introduction of rooms to lay out the dead in the communities, the organization of dispersed health regulations and their publications for common knowledge and especially the introduction of the smallpox vaccination in 1799 first time outside the UK. After the battle of Wagram (north to Vienna) in the Napoleonic war (July 6th, 1809) he had to care for the wounded and 56,000 dead soldiers on the battle field. In this action he contracted typhoid fever and consequently died on August 21st, 1809.

  20. chronicles of medical history first reports of clinical pharmacokinetics ...

    African Journals Online (AJOL)

    purpose of pharmacokinetics is to study the time course of drug and ... The German Friedrich Hartmut Dost (1910 – 1985) introduced the word. Pharmacokinetics. ..... University College Hospital, Ibadan for material on his father, Professor A.O. ...

  1. Proceedings of National Symposium on the Role of Academia in National Competitiveness and Total Quality Management (1st) Held in Morgantown, West Virginia on 18-20 July 1990

    Science.gov (United States)

    1990-07-20

    15 Don Ritter, Congressman from PA ......................................................... 27 David T. Kearns, Chairman...both higher quality education and better educaion about quality improvement techniques. Because of President Bush’s commitment to improving our...Good luck! God bless! 26 Congressional Perspective Don Ritter U.S. Representive 15th Congressional District, PA Introduction Thank you, it’s a real

  2. Reexamination of the InSb(111) and GaSb(111) Structures: Comment on 'Disorder in the Reconstructed (111)2x2 Surfaces of InSb and GaSb' by A. Belzner, E. Ritter and H. Schultz

    DEFF Research Database (Denmark)

    Robinson, I.K.; Bohr, J.; Feidenhans'l, R.;

    1989-01-01

    A recent article [Surface Sci. 209 (1989) 379] has attempted to improve the agreement between our original X-ray diffraction data [Phys. Rev. Letters 54 (1985) 1275; Surface Sci. 186 (1987) 499] and the proposed distorted vacancy model by the introduction of an additional, partially occupied atom...

  3. Cross-Sectional Comparison of Sleep-Disordered Breathing in Native Peruvian Highlanders and Lowlanders.

    Science.gov (United States)

    Pham, Luu V; Meinzen, Christopher; Arias, Rafael S; Schwartz, Noah G; Rattner, Adi; Miele, Catherine H; Smith, Philip L; Schneider, Hartmut; Miranda, J Jaime; Gilman, Robert H; Polotsky, Vsevolod Y; Checkley, William; Schwartz, Alan R

    2017-03-01

    Pham, Luu V., Christopher Meinzen, Rafael S. Arias, Noah G. Schwartz, Adi Rattner, Catherine H. Miele, Philip L. Smith, Hartmut Schneider, J. Jaime Miranda, Robert H. Gilman, Vsevolod Y. Polotsky, William Checkley, and Alan R. Schwartz. Cross-sectional comparison of sleep-disordered breathing in native Peruvian highlanders and lowlanders. High Alt Med Biol. 18:11-19, 2017.

  4. [St. Petersburg und Livland - und die Entwicklung der estnischen Literatur : Anton Schiefner (1817-1879) und Friedrich R. Kreutzwald (1803-1882) im Briefwechsel (1853-1879)] / Felix Köther

    Index Scriptorium Estoniae

    Köther, Felix

    2015-01-01

    Arvustus: St. Petersburg und Livland - und die Entwicklung der estnischen Literatur : Anton Schiefner (1817-1879) und Friedrich R. Kreutzwald (1803-1882) im Briefwechsel (1853-1879) / bearbeitet von Hartmut Walravens. Wiesbaden : Harrassowitz, 2013. (Orientalistik-Bibliographien und Dokumentationen ; Bd. 22)

  5. [St. Petersburg und Livland - und die Entwicklung der estnischen Literatur : Anton Schiefner (1817-1879) und Friedrich R. Kreutzwald (1803-1882) im Briefwechsel (1853-1879)] / Felix Köther

    Index Scriptorium Estoniae

    Köther, Felix

    2015-01-01

    Arvustus: St. Petersburg und Livland - und die Entwicklung der estnischen Literatur : Anton Schiefner (1817-1879) und Friedrich R. Kreutzwald (1803-1882) im Briefwechsel (1853-1879) / bearbeitet von Hartmut Walravens. Wiesbaden : Harrassowitz, 2013. (Orientalistik-Bibliographien und Dokumentationen ; Bd. 22)

  6. Geographische Revue: Zeitschrift für Literatur und Diskussion = Migration

    OpenAIRE

    2009-01-01

    Inhalt: Essays: Hartmut Esser: Ist das Konzept der Assimilation überholt? Ludger Pries: Transnationalismus, Migration und Inkorporation. Herausforderungen an Raum und Sozialwissenschaften Michael Bommes: Migration in der modernen Gesellschaft Diskussion: Christoph Scheuplein: Der Paradigmenwechsel als große Erzählung Harald Bathelt und Johannes Glückler: Plädoyer für eine relationale Wirtschaftsgeographie Einzelrezensionen

  7. Scalded skin syndrome

    Science.gov (United States)

    ... Severe bloodstream infection ( septicemia ) Spread to deeper skin infection ( cellulitis ) When to Contact a Medical Professional Call your provider or go to the emergency room if you have symptoms of this disorder. Prevention ... Alternative Names Ritter disease; Staphylococcal ...

  8. Download this PDF file

    African Journals Online (AJOL)

    dell

    2014-04-01

    Apr 1, 2014 ... There was one case of pin site infection and one case of cellulitis. .... The complications encountered included 2 cases (6%) of non-union. .... Ritter Z, Diamond R, Neuropathic Ankle Arthrodesis with Intramedullary Nail.

  9. Hypothetical Justifications

    Directory of Open Access Journals (Sweden)

    Bernd Lahno

    2009-01-01

    Full Text Available A basic conviction in moral non-cognitivism is: only hypothetical norms may be justified. Hartmut Kliemt argues for a moderate variant: there are only hypothetical justifications of norms whether the norms are hypothetical or categorical in kind. In this paper the concept of 'hypothetical justification' is analyzed. It is argued that hypothetical justifications are not of the kind that we should look for in normative ethics.

  10. Extrafloral nectar feeding by Strymon jacqueline Nicolay & Robbins, 2005 (Lepidoptera: Lycaenidae: Eumaeini

    Directory of Open Access Journals (Sweden)

    Roger Vila

    2006-10-01

    Full Text Available Adults of the dry area specialist Strymon jacqueline Nicolay & Robbins, 2005 (Lepidoptera: Lycaenidae: Eumaeini are here recorded feeding on extrafloral nectar of the large cactus Neoraimondia arequipensis var. gigantea (Werdermann & Backeberg Ritter. The significance of these observations is discussed in relation to lycaenid survival in a xeric environment, pollination and mate location.

  11. Human Contact in the Classroom: Exploring How Teachers Talk about and Negotiate Touching Students

    Science.gov (United States)

    Andrzejewski, Carey E.; Davis, Heather A.

    2008-01-01

    In a "risk society," as defined by Beck [(1992). "Risk society, towards a new modernity" (M. Ritter, Trans.) Newbury Park, CA: Sage, see also Castel, R. (1991). "From dangerousness to risk." In G. Burchell, C. Gordon & P. Miller (Eds.), "The Foucault effect: Studies in governmentality" (pp. 281-298). Chicago: The University of Chicago Press],…

  12. Examination of the Relationship Amongst Parenting Dimensions, Academic Achievement, Career Decision Making, and Commitment Anxiety among African American High School Students

    Science.gov (United States)

    Bennett-Garraway, Jocelyn M.

    2011-01-01

    Do parents play a significant role in the academic achievement and career decision making process of African American children? Studies have confirmed the importance of the role of parents and have even identified preferred parenting styles as having the best academic achievement (Dornbusch, Ritter, Leiderman, Roberts, & Fraleigh, 1987;…

  13. Analysis of Cognitive Tutor Geometry Curriculum

    Science.gov (United States)

    Bibi, Tauqir

    2010-01-01

    The Carnegie Learning Cognitive Tutor curricula are based on cognitive models, which include a representation of the learner's thinking, strategies, and misconceptions. The Cognitive Tutor curricula typically speed up learning and yield greater learning as compared to traditional math curricula (Morgan & Ritter, 2002; Sarkis, 2004; Koedinger,…

  14. Computer Generated Holography as a Three-Dimensional Display Medium

    Science.gov (United States)

    1990-12-01

    series of two dimensional images are reflected on an object screen resulting in an autostereoscopic , or true three dimensional, images. The advantages of...an attractive target to optimize. Jack Ritter has suggested a fast approximation to 3D Euclidean distance calculations (10:432). His methid uses no

  15. CoJACK: A High-Level Cognitive Architecture with Demonstrations of Moderators, Variability, and Implications for Situation Awareness

    Science.gov (United States)

    2012-01-01

    defined, to CoJACK (Ritter, Reifers, Klein, & Schoelles, 2007) based on task appraisal theory (e.g., Cannon, 1932; Lazarus & Folkman, 1984; Selye...Cambridge, MA: MIT Press. Lazarus , R. S., & Folkman, S. (1984). Stress, appraisal and coping. New York: Springer Publishing. Lovett, M. C., Daily, L

  16. Defense Headquarters: DOD Needs to Reassess Personnel Requirements for the Office of Secretary of Defense, Joint Staff, and Military Service Secretariats

    Science.gov (United States)

    2015-01-01

    requirements as part of the effort to identify efficiencies as directed by former Secretary of Defense Robert Gates in 2010, as part of the OSD...Director), Tracy Barnes, Gabrielle A. Carrington, Neil Feldman , David Keefer, Carol D. Petersen, Bethann E. Ritter Snyder, Michael Silver, Amie Steele

  17. Science and Technology Issues of Early Intercept Ballistic Missile Defense Feasibility

    Science.gov (United States)

    2011-09-01

    regional BM D system, the task Io ree ..:oncluded that the Earl y Intercept concept is not a pa11icularly usefitl organizing principal. llul more...BILL DELANEY MR. STEVE POST MR. NEIL DOAR MR. RICHARD RITTER COL LAURENCE DOBROT DR. BRAD ROBERTS MR. ERIC FORREST MR. KEVIN ROBINSON MS

  18. Primer Output and Initial Projectile Motion for 5.56- and 7.62-mm Ammunition

    Science.gov (United States)

    2015-09-01

    ARL-TR-7479 ● SEP 2015 US Army Research Laboratory Primer Output and Initial Projectile Motion for 5.56- and 7.62-mm Ammunition...Output and Initial Projectile Motion for 5.56- and 7.62-mm Ammunition by John J Ritter and Richard A Beyer Weapons and Materials Research...

  19. The Gordon Research Conference on Electron Spectroscopy Held in Wolfeboro, New Hampshire on 14-18 July 1986.

    Science.gov (United States)

    1986-07-18

    Halinovich (The Hebrew University of Jerusalem) SM11 Carbon K-Shell Excitation Spectra of Gaseous and Condensed Cyclic Hydrocarbons A. P. Hitchcock , D...94550 Bielefeld, West Germany D-4800 Ritter, Alfred Estabrook 6 Schowengerdt, F.D. Off Campus Virginia Tech Colorado School of Mines Blacksburg, VA 24061

  20. Feasibility Survey of Pilot Prevention and Health Intervention Strategies Management Information Analysis Center (PRHISM-IAC)

    Science.gov (United States)

    1993-06-01

    Langley AFB City: O’FALLON State: VA State: MO Zip: 23665 Zip: 63366 Last Name: Casiano Last Name: Carpenter First Name: Emmanuel 1. Col First Name...City: Atlanta State: OH State: GA Zip: 45237 Zip: 30333 Last Name: Ritter Last Name: Roger First Name: Todd Capt. First Name: Roland Col. Phone Number

  1. Origins of a Stereotype: Categorization of Facial Attractiveness by 6-Month-Old Infants

    Science.gov (United States)

    Ramsey, Jennifer L.; Langlois, Judith H.; Hoss, Rebecca A.; Rubenstein, Adam J.; Griffin, Angela M.

    2004-01-01

    Like adults, young infants prefer attractive to unattractive faces (e.g. Langlois, Roggman, Casey, Ritter, Rieser-Danner & Jenkins, 1987; Slater, von der Schulenburg, Brown, Badenoch, Butterworth, Parsons & Samuels, 1998). Older children and adults stereotype based on facial attractiveness (Eagly, Ashmore, Makhijani & Longo, 1991; Langlois,…

  2. Reflecting on the Japan-Chile Task-Based Telecollaboration Project for Beginner-Level Learners

    Science.gov (United States)

    Dunne, B. Greg

    2014-01-01

    Using O'Dowd and Ritter's (2006) Inventory of Reasons for Failed Communication in Telecollaborative Projects as a barometer, this article details the considerations and procedures followed in a task-based, asynchronous email telecollaboration project between EFL (English as a Foreign Language) learners in Japan and Chile. In a climate…

  3. Comparing Motor Development of Deaf Children of Deaf Parents and Deaf Children of Hearing Parents

    Science.gov (United States)

    Lieberman, Lauren J.; Volding, Lori; Winnick, Joseph P.

    2004-01-01

    Deaf children of Deaf parents perform better academically (Ritter-Brinton & Stewart, 1992), linguistically (Courtin, 2000; M. Harris, 2001; Vaccari & Marschark, 1997), and socially (Hadadian & Rose, 1991; M. Harris, 2001) than Deaf children of hearing parents. Twenty-nine Deaf children in residential schools were assessed to determine if a…

  4. Rachmaninov: Aleko / Kurt Malisch

    Index Scriptorium Estoniae

    Malisch, Kurt

    1998-01-01

    Uuest heliplaadist "Rachmaninov: Aleko; Der geizige Ritter; Francesca da Rimini. Opernchor Göteborg, Göteborgs Symfoniker, Neeme Järvi". DG 453 452-2 (3 CD:444 F ou 168 F chacun). 1996. TT:2 h 53'21"

  5. Comentario bibliográfico de Antihobbes. O sobre los límites del poder supremo y el derecho de coacción del ciudadano contra el soberano

    Directory of Open Access Journals (Sweden)

    Croxatto, Guido L.

    2013-12-01

    Full Text Available Comentario bibliográfico sobre Feuerbach, Paul Johann Anselm Ritter von, Anti-Hobbes. O sobre los límites del poder supremo y el derecho de coacción del ciudadano contra el soberano, Buenos Aires, Ed. Hammurabi, 2010.

  6. A Primer on Multivariate Analysis of Variance (MANOVA) for Behavioral Scientists

    Science.gov (United States)

    Warne, Russell T.

    2014-01-01

    Reviews of statistical procedures (e.g., Bangert & Baumberger, 2005; Kieffer, Reese, & Thompson, 2001; Warne, Lazo, Ramos, & Ritter, 2012) show that one of the most common multivariate statistical methods in psychological research is multivariate analysis of variance (MANOVA). However, MANOVA and its associated procedures are often not…

  7. Nõukogude modernism : perifeeria rääkimata lood / Mart Kalm ; intervjueerinud Sille Pihlak

    Index Scriptorium Estoniae

    Kalm, Mart, 1961-

    2012-01-01

    Näitus "Nõukogude modernism 1955-1991. Rääkimata lood" Viini Arhitektuurikeskuses. Kuraatorid: Katharina Ritter, Ekaterina Shapiro-Obermair, Alexandra Wachter. Näitusega kaasneb publikatsioon. Näituselt puudub Venemaa. Arhitektuuriajaloolane Mart Kalm eesti arhitektuurist ja oma ettekandest konverentsil

  8. Integrating Cross-Cultural Interaction through Video-Communication and Virtual Worlds in Foreign Language Teaching Programs: Is There an Added Value?

    Science.gov (United States)

    Canto, Silvia; Jauregi, Kristi; van den Bergh, Huub

    2013-01-01

    Organizing and implementing telecollaboration projects in foreign language curricula is not an easy endeavour (Belz & Thorne, 2006; Guth & Helm, 2010), as pedagogical, organizational and technical issues have to be addressed before cross-cultural interaction sessions can be carried out (O'Dowd & Ritter, 2006; O'Dowd, 2011). These issues make many…

  9. Integrating Cross-Cultural Interaction through Video-Communication and Virtual Worlds in Foreign Language Teaching Programs: Burden or Added Value?

    Science.gov (United States)

    Jauregi, Kristi; de Graaff, Rick; Canto, Silvia

    2011-01-01

    Organizing and implementing telecollaboration projects in foreign language curricula is not an easy endeavour (Belz & Thorne, 2006; Guth & Helm, 2010), as pedagogical, organizational and technical issues have to be addressed before cross-cultural interaction sessions can be carried out (O'Dowd & Ritter, 2006). These issues make many teaching…

  10. The Mujahedin-e Khalq in Iraq: A Policy Conundrum

    Science.gov (United States)

    2009-01-01

    www.rand.org/pubs/monographs/MG771 Goldsmith, Jack L. III, Assistant Attorney General, “‘Protected Persons’ in Occupied Iraq,” memorandum to Alberto ...R. Gonzales , Counsel to the President, March 18, 2004. Goodman, Amy, “Seymour Hersh and Scott Ritter on Iraq, WMDs and the Role of the Clinton

  11. 75 FR 4621 - Qualification of Drivers; Exemption Renewals; Vision

    Science.gov (United States)

    2010-01-28

    ... Ronald G. Austin, Rickey C. Dalton, Martiniano L. Espinosa, James G. LaBair, Dennis A. Leschke, Lonnie Lomax, Jr., Eugene C. Murphy, Carl W. Skinner, Jr., John H. Voigts and Daniel G. Wilson. In accordance...

  12. nmrfit

    Energy Technology Data Exchange (ETDEWEB)

    2017-09-01

    Nmrfit reads the output from a nuclear magnetic resonance (NMR) experiment and, through a number of intuitive API calls, produces a least-squares fit of Voigt-function approximations via particle swarm optimization.

  13. Uudised : Filharmoonia Kammerkoor Ameerikas. Peebo lisakontsert Tallinnas

    Index Scriptorium Estoniae

    2008-01-01

    Alates 3. novembrist annavad Eesti Filharmoonia Kammerkoor ja Tallinna Kammerorkester Tõnu Kaljuste juhatusel kontserte USA osariikide kultuurikeskustes. Kontserdiga 17. novembril New Yorgi Community Churchis (kavas Arvo Pärt, Erkki-Sven Tüür, Tõnu Kõrvits) tähistati ühtlasi vabariigi juubelit ning Eesti-USA viisavabaduse kehtestamist. Kontserdireisi viimane esinemine toimub 20. nov. Torontos. Metsosoprani Annely Peebo jõulukontserdid "Jõulureis läbi ajastute" toimuvad 16.-21. detsembrini Tallinnas (lisakontsert 21. dets.), Pärnus ja Viljandis. Peebot saadab klaveril pianist Hartmut Hudezeck Saksamaalt, kaastegev on Revalia Kammermeeskoor Hirvo Surva juhatusel

  14. Weak power law rheology of soft glassy and gelled materials

    CERN Document Server

    Patricio, Pedro

    2015-01-01

    We make a parallel excursion to the generalised Maxwell and Kelvin-Voigt models to find which general conditions may lead to the weak power law behaviours of the elastic and viscous moduli, $G'(w)\\sim G''(w)\\sim w^\\alpha$, with $0 y\\approx \\alpha$ and $y> x\\approx \\alpha$ for respectively the generalised Maxwell and Kelvin-Voigt models. Beyond this region, we find very different and interesting exponents.

  15. Algorithm of constructing hybrid effective modules for elastic isotropic composites

    Science.gov (United States)

    Svetashkov, A. A.; Miciński, J.; Kupriyanov, N. A.; Barashkov, V. N.; Lushnikov, A. V.

    2017-02-01

    The algorithm of constructing of new effective elastic characteristics of two-component composites based on the superposition of the models of Reiss and Voigt, Hashin and Strikman, as well as models of the geometric average for effective modules. These effective characteristics are inside forks Voigt and Reiss. Additionally, the calculations of the stress-strain state of composite structures with new effective characteristics give more accurate prediction than classical models do.

  16. Clarification of the Hashin-Shtrikman bounds on the effective elastic moduli of polycrystals with hexagonal, trigonal, and tetragonal symmetries

    Science.gov (United States)

    Watt, J.P.; Peselnick, L.

    1980-01-01

    Bounds on the effective elastic moduli of randomly oriented aggregates of hexagonal, trigonal, and tetragonal crystals are derived using the variational principles of Hashin and Shtrikman. The bounds are considerably narrower than the widely used Voigt and Reuss bounds. The Voigt-Reuss-Hill average lies within the Hashin-Shtrikman bounds in nearly all cases. Previous bounds of Peselnick and Meister are shown to be special cases of the present results.

  17. [Schelling and experiential science].

    Science.gov (United States)

    Breidbach, Olaf

    2004-01-01

    Schelling's philosophy of nature is shown to be part of the scientific discussions of his day, not set apart from it. His terminology describing the potentialities and polarities of nature was formed during Schelling's collaboration with the physicist Johann Wilhelm Ritter. This scientist adopted the schema Schelling had developed for the categorization of natural phenomena to describe the peculiar facts that interested him in his area of research. Thus Ritter was able to develop a classification of the various phenomena of animal galvanism. Thus it can be shown that the idealistic "Naturphilosophie" was part of the scientific culture of about 1800. It is to be interpreted as philosophy of science and has to be evaluated not only in a philosophically systematic way but in particular in its influence on the way scientific categories were ordered at the time. Thereby it can be shown that the idealistic vocabulary had close correspondence to French morphology and English Natural Theology.

  18. Strand Burner Results of AFP-001 Propellant with Inert Coating for Temperature Compensation

    Science.gov (United States)

    2015-10-01

    ARL-MR-0907 ● OCT 2015 US Army Research Laboratory Strand Burner Results of AFP -001 Propellant with Inert Coating for Temperature...Laboratory Strand Burner Results of AFP -001 Propellant with Inert Coating for Temperature Compensation by John J Ritter and Anthony Canami...COVERED (From - To) February 2015 4. TITLE AND SUBTITLE Strand Burner Results of AFP -001 Propellant with Inert Coating for Temperature Compensation

  19. Neuroscience-Enabled Complex Visual Scene Understanding

    Science.gov (United States)

    2012-04-12

    34, Rivista di Psicologia 49 (1): 7–30 • Kauppinen, Hannu. Seppanen, Tapio and Pietikainen, Matti. An Experimental Comparison of Autoregressive and...a Social Robot,“ IJCAI, pp. 1146-1151, 1999. [63] G. Heidemann, R. Rae, H. Bekel, I. Bax, and H. Ritter, ”Inte- grating Context-free and Context... social interaction. In Interna- tional Conference on Robotics, Automation, and Mecha- tronics (RAM 2006), Bangkok Thailand. Se, S., Lowe, D. G

  20. An International Symposium and Exhibition on Active Materials and Adaptive Structures.

    Science.gov (United States)

    2007-11-02

    Quantum Consultants, Inc. Implementing Smart Composites: Organizational/Environmental Issues 236 M. Martin, Michigan State University Activities of the...R. Measures, M. LeBlanc, K. McEwen, K. Shankar , R. Tennyson, University of Toronto Institute for Aerospace Studies Micro-Damage Analysis with...Ceramic Actuators 301 A. P. Ritter, A. Bailey, F. Poppe, N. Shankar & B. Rawal, Martin Marietta Smart Structural Composites with Inherent Sensing

  1. Staphylococcal Scalded Skin Syndrome in Child. A Case Report and a Review from Literature

    Directory of Open Access Journals (Sweden)

    Grama Alina

    2016-10-01

    Full Text Available Staphylococcal scalded skin syndrome (SSSS is the medical term used to define a skin condition induced by the exfoliative toxins produced by Staphylococcus aureus. The disorder is also known as Ritter disease, bullous impetigo, neonatal pemphigus, or staphylococcal scarlet fever. The disease especially affects infants and small children, but has also been described in adults. Prompt therapy with proper antibiotics and supportive treatment has led to a decrease in the mortality rate.

  2. Variants of Uncertainty

    Science.gov (United States)

    1981-05-15

    Variants of Uncertainty Daniel Kahneman University of British Columbia Amos Tversky Stanford University DTI-C &%E-IECTE ~JUNO 1i 19 8 1j May 15, 1981... Dennett , 1979) in which different parts have ac- cess to different data, assign then different weights and hold different views of the situation...2robable and t..h1 provable. Oxford- Claredor Press, 1977. Dennett , D.C. Brainstorms. Hassocks: Harvester, 1979. Donchin, E., Ritter, W. & McCallum, W.C

  3. A System Approach to Navy Medical Education and Training. Appendix 24. Equipment Repair Technician.

    Science.gov (United States)

    1974-08-31

    ACRYLIC PACO 11 1ELECTROPLATER (SILVER, GOLD AND COPPER) 12 IPANOREX X-RAY UNIT I{ 13 ICASTING MACHINE, CHROME COBALT 14 ICASTING MACHINE, DENTAL METALS...33 1PDBOESt SURG1CAL9 ELECTRIC 34 IMETAL LOCATOR I 35 ICHAIR, SURGEON, RECLINING 36 "|MEDICAL UNIT, RITTER MODEL 37 (DRILL, MICRO SHEA 38 ICAST ...ERGOMETER 44 IHEARING AID KITS 45 IALTERNATING PRESSURE PAD AND MATTRESS 46 *JaRiLt, AIR STRYKER 41 ICASTING MACHINE BROKEN ARM, KERR 48 ISAWo PLASTER

  4. Manager-Organization Linkages: The Impact of Changing Work Environments.

    Science.gov (United States)

    1979-11-01

    creation of the rest of the occupational characteristics that have come to be associated with the professions (cf. Ritzer , 1977). One of the more...Institute for Social Research, Ann Arbor, Mi. Ritzer , G. (1977). Working: Conflict and Change, Second Edition, Prentice-Hall, Englewood Cliffs, NJ. Schein, E... George E. Rowland Temple University, The Merit Center Ritter Annex, 9th Floor College of Education Philadephia, PA 19122 Dr. Irwin G. Sarason

  5. Solar power stations for all roofs - two enterprises combine solar power generations and franchising; Fuer jedes Dach ein Solarkraftwerk - wie zwei Unternehmer Sonnenenergie und Franchising verbinden

    Energy Technology Data Exchange (ETDEWEB)

    Meyeren, T. von

    1997-12-31

    A project is presented in which two partners cooperate in roof-mounted solar power units. Prospects are good: Although the German market for photovolatic systems is still not in full swing, there are good chances worldwide. (orig.) [Deutsch] `Die Zeit is reif, etwas zu tun` fanden Lothar Kuhn, Elektromeister aus Starzach in Wuerttemberg, und Alfred Ritter, Inhaber des Schokoladen-Unternehmens Ritter Sport, angesichts der Zurueckhaltung der grossen deutschen Energieunternehmen gegenueber der Solar-Energie. Sie beschlossen, sich der Energieinteressen der Menschen konstruktiv anzunehmen, der eine - Alfred Ritter - als Kapitalgeber, der andere - Lothar Kuhn - als geschaeftsfuehrender Gesellschafter der im Juni 1996 gegruendeten Sunlive Solarnetwork GmbH and Co KG, auf Schloss Weitenburg in Starzach und zugleich Experte auf dem Gebiet der Solarstrom-Erzeugung. Die Vision:Jedes Dach soll ein solares E-Werk werden. Die Chancen: Nie besser als heute. Der deutsche Photovoltaik-Markt ist unterentwickelt, Prognosen bescheinigen jedoch weltweit gross Entwicklungschancen in wirtschaftlicher und technischer Hinsicht.(orig./AKF)

  6. On Advantages of the Kelvin Mapping in Finite Element Implementations of Deformation Processes

    CERN Document Server

    Nagel, Thomas; Moerman, Kevin M; Kolditz, Olaf

    2016-01-01

    Classical continuum mechanical theories operate on three-dimensional Eu-clidian space using scalar, vector, and tensor-valued quantities usually up to the order of four. For their numerical treatment, it is common practice to transform the relations into a matrix-vector format. This transformation is usually performed using the so-called Voigt mapping. This mapping does not preserve tensor character leaving significant room for error as stress and strain quantities follow from different mappings and thus have to be treated differently in certain mathematical operations. Despite its conceptual and notational difficulties having been pointed out, the Voigt mapping remains the foundation of most current finite element programmes. An alternative is the so-called Kelvin mapping which has recently gained recognition in studies of theoretical mechanics. This article is concerned with benefits of the Kelvin mapping in numerical modelling tools such as finite element software. The decisive difference to the Voigt mapp...

  7. Effects of the Spectral Line Broadened Model on the Performance of a Flowing Chemical Oxygen-Iodine Laser

    Institute of Scientific and Technical Information of China (English)

    高智; 胡利民

    2002-01-01

    A new gain saturation model of chemical oxygen-iodine lasers (COILs) is deduced from the conservation equations of the population number of upper and lower lasing levels. The present model is compared with both the Voigt profile function model and its low-pressure limit model. The differences between the Voigt profile function model or its low-pressure limit model and the model presented here are pointed out, such as the length of power extraction, the optimal range of the threshold gain. These differences are useful for the optimization of COIL adjustable parameters.

  8. Variational method of determining effective moduli of polycrystals with tetragonal symmetry

    Science.gov (United States)

    Meister, R.; Peselnick, L.

    1966-01-01

    Variational principles have been applied to aggregates of randomly oriented pure-phase polycrystals having tetragonal symmetry. The bounds of the effective elastic moduli obtained in this way show a substantial improvement over the bounds obtained by means of the Voigt and Reuss assumptions. The Hill average is found to be a good approximation in most cases when compared to the bounds found from the variational method. The new bounds reduce in their limits to the Voigt and Reuss values. ?? 1966 The American Institute of Physics.

  9. Variational method of determining effective moduli of polycrystals: (A) hexagonal symmetry, (B) trigonal symmetry

    Science.gov (United States)

    Peselnick, L.; Meister, R.

    1965-01-01

    Variational principles of anisotropic elasticity have been applied to aggregates of randomly oriented pure-phase polycrystals having hexagonal symmetry and trigonal symmetry. The bounds of the effective elastic moduli obtained in this way show a considerable improvement over the bounds obtained by means of the Voigt and Reuss assumptions. The Hill average is found to be in most cases a good approximation when compared to the bounds found from the variational method. The new bounds reduce in their limits to the Voigt and Reuss values. ?? 1965 The American Institute of Physics.

  10. Pragmática, sociedade (e a alma, uma entrevista com Jacob Mey

    Directory of Open Access Journals (Sweden)

    Daniel do Nascimento e Silva

    2014-01-01

    Full Text Available Jacob Mey, o linguista que fundou (em 1977, com Hartmut Haberland o Journal of Pragmatics e autor de inúmeros livros e artigos no campo da pragmática, visitou o Brasil em novembro/dezembro de 2012, por ocasião da homenagem ao trabalho do pragmaticista Kanavillil Rajagopalan, realizada na Unicamp, onde Rajagopalan desenvolveu trabalho exemplar. A visita de Mey ao Brasil foi uma convite à reflexão sobre o objeto da pragmática, suas vizinhanças, seus principais problemas e sua agenda. Esta entrevista, realizada no Rio de Janeiro, conta a trajetória de Jacob Mey e sua visada crítica sobre os principais temas e problemas da pragmática.

  11. Can a Humean be a Contractarian?

    Directory of Open Access Journals (Sweden)

    Robert Sugden

    2009-01-01

    Full Text Available In this paper I argue, contrary to Hartmut Kliemt, that it is possible to be both a Humean and, in James Buchanan's sense, a contractarian. Hume sees principles of justice and political allegiance not as actual or hypothetical products of explicit agreement, but as conventions that have emerged spontaneously. However, it is fundamental to Hume's analysis that conventions are mutually advantageous, and hence cognate with agreements. The core idea in Buchanan's contractarianism is that the proper role of government is to implement voluntary exchanges between individuals, not to define and maximise a unified conception of social welfare. Although real politics cannot be based entirely on unanimous agreement, the voluntary exchange approach provides a valuable structure for normative economics.

  12. 走进美国兰登书屋

    Institute of Scientific and Technical Information of China (English)

    练小川

    2008-01-01

    @@ 这几天,英美出版界盛传,在位10年之久的兰登书屋总裁彼得·奥尔森(Peter Olson)数周内便要卸职,其中原委众说纷纭.分析,兰登书屋2007年的业绩不佳,销售额和经营利润均比2006年下降5%左右,因此贝塔斯曼的新老总哈特穆·奥斯特洛夫斯基(Hartmut Ostrowskj)对奥尔森失去信心;

  13. Health Care Rationing and Distributive Justice

    Directory of Open Access Journals (Sweden)

    Friedrich Breyer

    2009-01-01

    Full Text Available The rapid progress in medical technology makes it unavoidable to ration health care. In the discussion how to ration many people claim that principles of justice in distributing scarce resources should be applied. In this paper we argue that medical resources are not scarce as such but scarcity is a necessary by-product of collective financing arrangements such as social health insurance. So the right question to ask is the determination of the benefit package of such an institution. Hartmut Kliemt is currently involved in a commendable interdisciplinary research project in which principles of 'prioritization' of medical care are studied. This contribution adds a specific perspective to this endeavour: we ask how the goal of distributive justice can be interpreted in this context and compare different approaches to implementing 'just' allocation mechanisms.

  14. Cell scientist to watch - Arun Shukla.

    Science.gov (United States)

    2017-02-15

    Arun Shukla received his master's degree in Biotechnology from the Jawaharlal Nehru University in New Delhi, and joined the lab of Nobel laureate Hartmut Michel at the Max Planck Institute of Biophysics in Frankfurt, Germany, for his PhD. He then moved to the United States for his postdoctoral work with Robert Lefkowitz at Duke University (Durham, NC) in a very close collaboration with Brian Kobilka (Stanford University, CA). Arun became an Assistant Professor in the Department of Medicine at Duke University in 2011, before returning to India in April 2014 as an Assistant Professor at the Indian Institute of Technology (IIT) in Kanpur as a Wellcome Trust DBT India Alliance Intermediate Fellow. His research is centred on G-protein-coupled receptors (GPCRs), and he applies molecular, cellular and structural biology methods to understand the signalling and activation pathways of GPCRs.

  15. Signature of the celestial spheres discovering order in the solar system

    CERN Document Server

    Warm, Harmut

    2010-01-01

    "A milestone in modern research on the the harmony of the spheres." - Novalis magazine "This book reignites the debate on the harmony of the spheres." - Das Goetheanum Is the solar system ordered, or is it simply the result of random and chaotic accidents? This book takes us on a powerful and compelling journey of discovery, revealing the celestial spheres' astonishingly complex patterns. The movements of the planets are found to correspond accurately with simple geometric figures and musical intervals, pointing to an exciting new perspective on the ancient idea of a "harmony of the spheres". Hartmut Warm's detailed presentation incorporates the distances, velocities and periods of conjunction of the planets, as well as the rotations of the Sun, Moon and Venus. Numerous graphics - including colour plates - illustrate the extraordinary beauty of the geometrical forms that result when the movements of several planets are viewed in relation to one another. In addition, the author describes and analyses the conce...

  16. Dispersion relation for localized magnetic polaritons propagating at the junction of two ferromagnetic/ non-magnetic superlattices

    Indian Academy of Sciences (India)

    R T Tagiyeva

    2004-09-01

    Localized magnetic polaritons are investigated in the systems consisting of two magnetic superlattices, coupled by a ferromagnetic contact layer. The general dispersion relation for localized magnetic polaritons are derived in the framework of the electromagnetic wave theory in the Voigt geometry by the `transfer' matrix method. The numerical calculations were carried out for different parameters of the superlattices and contact layer and then discussed.

  17. Fiscal Food Policy

    DEFF Research Database (Denmark)

    G. Nicholls, Stuart; Gwozdz, Wencke; Reisch, Lucia;

    2011-01-01

    When it comes to buying food, price is influential, but is a ‘fat tax’ the answer to curb obesity? Dr Stuart G Nicholls from Lancaster University, Assistant Professor Dr Wencke Gwozdz and Professor, Dr Lucia A Reisch from Copenhagen Business School and Dr Kristin Voigt from Lancaster University l...... look at whether a fiscal policy would work....

  18. Compact cryogenic Kerr microscope for time-resolved studies of electron spin transport in microstructures

    NARCIS (Netherlands)

    Rizo, P. J.; Pugzlys, A.; Liu, J.; Reuter, D.; Wieck, A. D.; van der Wal, C. H.; van Loosdrecht, P. H. M.; Pugžlys, A.

    2008-01-01

    A compact cryogenic Kerr microscope for operation in the small volume of high-field magnets is described. It is suited for measurements both in Voigt and Faraday configurations. Coupled with a pulsed laser source, the microscope is used to measure the time-resolved Kerr rotation response of

  19. Populations of Radial Glial Cells Respond Differently to Reelin and Neuregulin1 in a Ferret Model of Cortical Dysplasia

    Science.gov (United States)

    2010-10-28

    out of the ventricular zone, but do not play a role in allowing further movement toward the cortical plate. Materials and Methods Ethics Statement...transformation into astrocytes. Anatomy and embryology 156(2): 115–152. 11. Voigt T (1989) Development of glial cells in the cerebral wall of ferrets

  20. Bayesian inversion of free oscillations for Earth's radial (an)elastic structure

    NARCIS (Netherlands)

    de Wit, R. W L; Käufl, P.J.; Valentine, A. P.; Trampert, J.

    2014-01-01

    We perform a Bayesian inversion of degree-zero spheroidal mode splitting function measurements for radial (1-D) Earth structure, in terms of the Voigt averages of P-wave (VP) and S-wave (VS) velocities, density, bulk and shear attenuation, using neural networks. The method is flexible and allows us

  1. A Manual on the Evaluation of Information Centers and Services (Manuel pour l’Evaluation des Centres et Services d’Information)

    Science.gov (United States)

    1991-04-01

    compute costs of resources or services. conductA ~ per user). More complex models include statistical correlation, multiple regression and conjoint In...Publishing, 1982. "Information and Work." In Progress in Communication Slater, Margaret. Sciences:, Volume 2, eds. Brenda Dervin and Melvin Voigt, " Social

  2. TÜ tähistab rahvusülikooli aastapäeva

    Index Scriptorium Estoniae

    2010-01-01

    Emakeelse ülikooli 91. aastapäeva tähistamisest. Aktusel promoveeriti 103 doktorit ja 5 audoktorit. Audoktoriks said: Jaan Einasto (Eesti), Vilmos Voigt (Ungari), Pekka Topias Männistö (Soome), William J. Mitsch (USA), Lars Oreland (Rootsi)

  3. Tunable Optical Delay in Doppler-Broadened Cesium Vapor

    Science.gov (United States)

    2010-12-01

    1971; Bernabeu and Alvarez, 1980; Tornos and Amare, 1986), normally accomplished at low temperatures to reduce Cs-Cs collisions. Wall collisions and...algorithms for the voigt profile function. Computers in Physics 7 (6), 627–631. Tornos , J. and J. C. Amare (1986). Hyperfine relaxation of an optically pumped

  4. Fostering reflective practice with mobile technologies

    NARCIS (Netherlands)

    Tabuenca, Bernardo; Verpoorten, Dominique; Ternier, Stefaan; Westera, Wim; Specht, Marcus

    2012-01-01

    Tabuenca, B., Verpoorten, D., Ternier, S., Westera, W., & Specht, M. (2012). Fostering reflective practice with mobile technologies. In A. Moore, V. Pammer, L. Pannese, M. Prilla, K. Rajagopal, W. Reinhardt, Th. D. Ullman, & Ch. Voigt (Eds.), Proceedings of the 2nd Workshop on Awareness and Reflecti

  5. Understanding the meaning of awareness in Research Networks

    NARCIS (Netherlands)

    Reinhardt, Wolfgang; Mletzko, Christian; Sloep, Peter; Drachsler, Hendrik

    2013-01-01

    Reinhardt, W., Mletzko, C., Sloep, P. B., & Drachsler, H. (2012). Understanding the meaning of awareness in Research Networks. In A. Moore, V. Pammer, L. Pannese, M. Prilla, K. Rajagopal, W. Reinhardt, Th. D. Ullman, & Ch. Voigt (Eds.), Proceedings of the 2nd Workshop on Awareness and Reflection in

  6. Proceedings of the 2nd Workshop on Awareness and Reflection in Technology-Enhanced Learning

    NARCIS (Netherlands)

    Moore, Adam; Pammer, Viktoria; Pannese, Lucia; Prilla, Michael; Rajagopal, Kamakshi; Reinhardt, Wolfgang; Ullman, Thomas; Voigt, Christian

    2013-01-01

    Moore, A., Pammer, V., Pannese, L., Prilla, M., Rajagopal, K., Reinhardt, W., Ullman, Th. D., & Voigt, Ch. (Eds.) (2012). Proceedings of the 2nd Workshop on Awareness and Reflection in Technology Enhanced Learning. In conjunction with the 7th European Conference on Technology Enhanced Learning: 21st

  7. Utilization of Electrocardiographic P-wave Duration for AV Interval Optimization in Dual-Chamber Pacemakers.

    Science.gov (United States)

    Sorajja, Dan; Bhakta, Mayurkumar D; Scott, Luis Rp; Altemose, Gregory T; Srivathsan, Komandoor

    2010-09-05

    Empiric programming of the atrio-ventricular (AV) delay is commonly performed during pacemaker implantation. Transmitral flow assessment by Doppler echocardiography can be used to find the optimal AV delay by Ritter's method, but this cannot easily be performed during pacemaker implantation. We sought to determine a non-invasive surrogate for this assessment. Since electrocardiographic P-wave duration estimates atrial activation time, we hypothesized this measurement may provide a more appropriate basis for programming AV intervals. A total of 19 patients were examined at the time of dual chamber pacemaker implantation, 13 (68%) being male with a mean age of 77. Each patient had the optimal AV interval determined by Ritter's method. The P-wave duration was measured independently on electrocardiograms using MUSE® Cardiology Information System (version 7.1.1). The relationship between P-wave duration and the optimal AV interval was analyzed. The P-wave duration and optimal AV delay were related by a correlation coefficient of 0.815 and a correction factor of 1.26. The mean BMI was 27. The presence of hypertension, atrial fibrillation, and valvular heart disease was 13 (68%), 3 (16%), and 2 (11%) respectively. Mean echocardiographic parameters included an ejection fraction of 58%, left atrial index of 32 ml/m(2), and diastolic dysfunction grade 1 (out of 4). In patients with dual chamber pacemakers in AV sequentially paced mode and normal EF, electrocardiographic P-wave duration correlates to the optimal AV delay by Ritter's method by a factor of 1.26.

  8. En el centenario del viaje a Oriente. Fotografías, cartas y dibujos

    OpenAIRE

    Montes-Serrano, C. (Carlos)

    2011-01-01

    En 2011 se cumple el centenario del viaje a Oriente de Le Corbusier, con el que de alguna manera da fin a su periodo de formación autodidacta. Con este ensayo se desea evocar el contexto artístico e intelectual del joven Jeanneret en el momento de iniciar el viaje, a partir de algunas cartas que envía a Charles L’Eplattenier y a William Ritter, prestando especial atención al carácter finalista que van adquiriendo sus dibujos, bocetos y pinturas en aquellos decisivos meses.

  9. Direct, two-step synthetic pathway to novel dibenzo[a,c]phenanthridines.

    Science.gov (United States)

    Churruca, Fátima; SanMartin, Raul; Carril, Mónica; Urtiaga, Miren Karmele; Solans, Xavier; Tellitu, Imanol; Domínguez, Esther

    2005-04-15

    Novel dibenzo[a,c]phenanthridines are prepared regioselectively by the application of a straightforward synthetic pathway, starting from new 3,4-diaryl- and 3,4-dihydro-3,4-diarylisoquinolines prepared via Ritter-type heterocyclization and the more classical two-step reductive amination/Bischler-Napieralski cyclization of triarylethanones, respectively. A comparative study of nonphenolic oxidative coupling methodologies provides a highly efficient procedure, based on the hypervalent iodine reagent phenyliodine(III) bis(trifluoroacetate) (PIFA), to accomplish the final coupling step.

  10. Is "Spike" a Reliable Feature in Porb Distribution of AM HER Stars?

    CERN Document Server

    Golovin, Alex; Pavlenko, Elena

    2008-01-01

    Orbital periods in AM Her stars (polars) are synchronized with spin periods of white dwarf by its high magnetic field. Since the last study of Porb distribution of these systems, the number of known objects of such type has more than doubled. This challenged us to compile a new updated catalogue of cataclysmic variables with highly magnetic white dwarfs (polars) and to study their Porb distribution. In this paper we also discus if "spike" is reliable feature in the distribution. ("Spike" is a concentration of polars in the distribution of their orbital periods near Porb = 114 min and was previously discussed by Ritter & Kolb (1992) and Shahbaz & Wood (1996).)

  11. Synthesis of D-fructose-derived spirocyclic 2-substituted-2-oxazoline ribosides

    Directory of Open Access Journals (Sweden)

    Madhuri Vangala

    2015-11-01

    Full Text Available The TMSOTf-mediated synthesis of β-configured spirocyclic 2-substituted-2-oxazoline ribosides was achieved using a “Ritter-like” reaction in toluene through nucleophilic addition of electron-rich nitriles to the oxacarbenium ion intermediate of 1,2;3,4-di-O-isopropylidene-β-D-psicofuranose derivatives with concomitant intramolecular trapping of the C2 hydroxymethyl group on the electrophilic nitrilium carbon. These carbohydrate-derived spirooxazolines are stable and were obtained in good yield with high stereoselectivity due to the conformational rigidity imparted by the 3,4-isopropylidene group.

  12. Effect of Contact Damage on the Strength of Ceramic Materials.

    Science.gov (United States)

    1983-10-01

    Journal of the American Ceramic Society, in press. [3) Jakus, K., Ritter, J.E., and Babinski , R.C., this volume. [4] Dabbs, T.P., Lawn, B.R., and Kelly...effectively reducing the contact angle, thereby leaving a residual stress of diminished magnitude but of same sign acting on the fault. The normal stress NN...simply reduces in magnitude to residual level, NN actually reverses sign , at P ;z 0.3 P, enroute to its ultimate tensile state. 160 Applied Tension

  13. Integrality of representations of finite groups

    OpenAIRE

    Hofmann, Tommy

    2016-01-01

    Since the early days of representation theory of finite groups in the 19th century, it was known that complex linear representations of finite groups live over number fields, that is, over finite extensions of the field of rational numbers. While the related question of integrality of representations was answered negatively by the work of Cliff, Ritter and Weiss as well as by Serre and Feit, it was not known how to decide integrality of a given representation. In this thesis we show tha...

  14. Robust cluster analysis and variable selection

    CERN Document Server

    Ritter, Gunter

    2014-01-01

    Clustering remains a vibrant area of research in statistics. Although there are many books on this topic, there are relatively few that are well founded in the theoretical aspects. In Robust Cluster Analysis and Variable Selection, Gunter Ritter presents an overview of the theory and applications of probabilistic clustering and variable selection, synthesizing the key research results of the last 50 years. The author focuses on the robust clustering methods he found to be the most useful on simulated data and real-time applications. The book provides clear guidance for the varying needs of bot

  15. Adaptive-Wall Wind-Tunnel Investigations

    Science.gov (United States)

    1981-02-01

    CALSPAN ADVANCED TECHNOLOGY CENTER A DA PTI VE. WA L L WIND- TUNNEL IN VES TIGA TIONS J.C. Erickson , Jr., C.E. Wittliff, C. Padova and G.F. Homicz...Cooper as technical monitor, and by the Air Force Office of Scientific Research, initially with Mr. Milton Rogers and later with Dr. James D. Wilson as...technical monitors. The late Mr. R. J. Vidal was principai investigator until May 1978 and was followed by Dr. J. C. Erickson , Jr. Dr. A. Ritter, Head

  16. Elastic constants of calcite

    Science.gov (United States)

    Peselnick, L.; Robie, R.A.

    1962-01-01

    The recent measurements of the elastic constants of calcite by Reddy and Subrahmanyam (1960) disagree with the values obtained independently by Voigt (1910) and Bhimasenachar (1945). The present authors, using an ultrasonic pulse technique at 3 Mc and 25??C, determined the elastic constants of calcite using the exact equations governing the wave velocities in the single crystal. The results are C11=13.7, C33=8.11, C44=3.50, C12=4.82, C13=5.68, and C14=-2.00, in units of 1011 dyncm2. Independent checks of several of the elastic constants were made employing other directions and polarizations of the wave velocities. With the exception of C13, these values substantially agree with the data of Voigt and Bhimasenachar. ?? 1962 The American Institute of Physics.

  17. Spectroscopic Study of Air-Broadened Nitrous Oxide in the ν_3 Band

    Science.gov (United States)

    Hashemi, Robab; Naseri, Hossein; Predoi-Cross, Adriana; Smith, Mary Ann H.; Devi, V. Malathy

    2017-06-01

    We present results of a recent analysis of laboratory spectra to determine line positions, intensities, air-broadened half-widths and pressure-induced shifts and their temperature dependences in the ν_3 fundamental band of N_2O. The spectra used in this study were recorded using the 1-m McMath-Pierce Fourier transform spectrometer while it was located at the National Solar Observatory on Kitt Peak, AZ. Multispectrum analysis software was used to retrieve the line parameters using the Voigt and speed-dependent Voigt line profiles. The line mixing coefficients were calculated using the Exponential Power Gap scaling law. Comparisons with similar published results will be presented. D. C. Benner, C. P. Rinsland, V. Malathy Devi, M. A. H. Smith, D. Atkins, JQSRT 53 (1995) 705-721.

  18. Numerical analysis of road pavement thermal deformability, based on Biot viscoelastic model of porous medium

    Science.gov (United States)

    Bartlewska-Urban, Monika; Zombroń, Marek; Strzelecki, Tomasz

    2016-03-01

    The following study presents numerical calculations for establishing the impact of temperature changes on the process of distortion of bi-phase medium represented using Biot consolidation equations with Kelvin-Voigt rheological skeleton presented, on the example of thermo-consolidation of a pavement of expressway S17. We analyzed the behavior of the expressway under the action of its own weight, dynamic load caused by traffic and temperature gradient. This paper presents the application of the Biot consolidation model with the Kelvin-Voigt skeleton rheological characteristics and the influence of temperature on the deformation process is taken into account. A three-dimensional model of the medium was created describing the thermal consolidation of a porous medium. The 3D geometrical model of the area under investigation was based on data obtained from the land surveying and soil investigation of a 200 m long section of the expressway and its shoulders.

  19. Study on Stress Development in the Phase Transition Layer of Thermal Barrier Coatings

    Directory of Open Access Journals (Sweden)

    Yijun Chai

    2016-09-01

    Full Text Available Stress development is one of the significant factors leading to the failure of thermal barrier coating (TBC systems. In this work, stress development in the two phase mixed zone named phase transition layer (PTL, which grows between the thermally grown oxide (TGO and the bond coat (BC, is investigated by using two different homogenization models. A constitutive equation of the PTL based on the Reuss model is proposed to study the stresses in the PTL. The stresses computed with the proposed constitutive equation are compared with those obtained with Voigt model-based equation in detail. The stresses based on the Voigt model are slightly higher than those based on the Reuss model. Finally, a further study is carried out to explore the influence of phase transition proportions on the stress difference caused by homogenization models. Results show that the stress difference becomes more evident with the increase of the PTL thickness ratio in the TGO.

  20. Application of ultrasonic guided waves to the characterization of texture in metal sheets of cubic and hexagonal crystallites

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yan.

    1990-10-08

    Ultrasonic techniques have recently been applied to the texture characterization in polycrystalline aggregates of hexagonal crystals. The basis of this application lies in the relations between the elastic constants {bar C}{sub ij} of the aggregates, which can be inferred from ultrasonic wave velocity measurements, and the orientation distribution coefficients. This communication present such relations for aggregates which possess orthotopic material symmetry and hexagonal crystal symmetry for Voigt, Reuss, and Hill averaging methods in a unified and concise representation.

  1. Asymptotic stability and blow up for a semilinear damped wave equation with dynamic boundary conditions

    KAUST Repository

    Gerbi, Stéphane

    2011-12-01

    In this paper we consider a multi-dimensional wave equation with dynamic boundary conditions, related to the KelvinVoigt damping. Global existence and asymptotic stability of solutions starting in a stable set are proved. Blow up for solutions of the problem with linear dynamic boundary conditions with initial data in the unstable set is also obtained. © 2011 Elsevier Ltd. All rights reserved.

  2. Decentralizing Statistical Accuracy Control Responsibility to the Ship Production Workforce (The National Shipbuilding Research Program)

    Science.gov (United States)

    1987-01-01

    was understood and will be applied correctly. The future and continued success of this program is not guaranteed. Cementing the gains made to date...nate rework. (Right) Enjoying a potluck lunch, the Table 10 team includes (seated, from left) Jose Murillo, Tim Plttrizzi, Frank de la Cruz, Jorge Valdez...Nguyen, Gabe Martinez, Hung Cao, Dave Voigt, Jr,, Jorge Castro, Phil Murray, Henry Posey, Ben Fuentes, Aian Richle, and Cristobal Orozco . Not present

  3. A Raman Study of Titanate Nanotubes

    African Journals Online (AJOL)

    NJD

    The effect of the addition of NaOH or KOH on commercial Degussa Titania P25 ... that the nanotubes are built from a layered titanate structure, ... about 1 mg material into 1 mL ethanol for 10 minutes and a few ... effect of washing on the tube properties. ..... 25 Z.R. Tian, J.A. Voigt, J. Liu, B. McKenzie and H. Xu, J. Am. Chem.

  4. Modelling water hammer in viscoelastic pipelines: short brief

    Science.gov (United States)

    Urbanowicz, K.; Firkowski, M.; Zarzycki, Z.

    2016-10-01

    The model of water hammer in viscoelastic pipelines is analyzed. An appropriate mathematical model of water hammer in polymer pipelines is presented. An additional term has been added to continuity equation to describe the retarded deformation of the pipe wall. The mechanical behavior of viscoelastic material is described by generalized Kelvin-Voigt model. The comparison of numerical simulation and experimental data from well known papers is presented. Short discussion about obtained results are given.

  5. X-Ray Diffractometry of Thin Layers - Possibilities and Problems

    Directory of Open Access Journals (Sweden)

    Vladimir Zucha

    2005-01-01

    Full Text Available Efficieney of two deconvolution methods used in X-ray powder diffraction analysis is compared for thin films of Pd and Pt. The first method is the classical Stokes method and the second one is method of indirect deconvolution. But calculated integral breadth of Gauss and Cauchy components of Voigt function which describe the physical broadening are different. The analysis of the all found pheromones show that the method of indirect deconvolution gives more accurate results.

  6. Role of biplane digital subtraction angiography, and 3D rotational angiography in craniopagus twins: A case report, detailed pictorial evaluation, and review of literature.

    Science.gov (United States)

    Sudha, Lakshmi; Dev, Bhawna; Kamble, Ravindra; Joseph, Santhosh

    2009-07-01

    Cranially conjoined twins (craniopagus) are regarded as one of the rarest human malformations. Craniopagus represents 2 to 6% of conjoined twins and is the rarest type of disorder. A conventional angiogram with three dimensions is needed to confirm the exact extent of sharing of the arterial / venous tree. 3D angiography was first proposed by CORNELIUS and advanced into clinical practice by VOIGT in 1975. We present a case of craniopagus vertical type II twins, evaluated for cerebral circulation.

  7. Role of biplane digital subtraction angiography, and 3D rotational angiography in craniopagus twins: A case report, detailed pictorial evaluation, and review of literature

    OpenAIRE

    Lakshmi Sudha; Bhawna Dev; Ravindra Kamble; Santhosh Joseph

    2009-01-01

    Cranially conjoined twins (craniopagus) are regarded as one of the rarest human malformations. Craniopagus represents 2 to 6% of conjoined twins and is the rarest type of disorder. A conventional angiogram with three dimensions is needed to confirm the exact extent of sharing of the arterial / venous tree. 3D angiography was first proposed by CORNELIUS and advanced into clinical practice by VOIGT in 1975. We present a case of craniopagus vertical type II twins, evaluated for cerebral circulat...

  8. Role of biplane digital subtraction angiography, and 3D rotational angiography in craniopagus twins: A case report, detailed pictorial evaluation, and review of literature

    Directory of Open Access Journals (Sweden)

    Lakshmi Sudha

    2009-01-01

    Full Text Available Cranially conjoined twins (craniopagus are regarded as one of the rarest human malformations. Craniopagus represents 2 to 6% of conjoined twins and is the rarest type of disorder. A conventional angiogram with three dimensions is needed to confirm the exact extent of sharing of the arterial / venous tree. 3D angiography was first proposed by CORNELIUS and advanced into clinical practice by VOIGT in 1975. We present a case of craniopagus vertical type II twins, evaluated for cerebral circulation.

  9. Vibration suppression with approximate finite dimensional compensators for distributed systems: Computational methods and experimental results

    Science.gov (United States)

    Banks, H. T.; Smith, Ralph C.; Wang, Yun

    1994-01-01

    Based on a distributed parameter model for vibrations, an approximate finite dimensional dynamic compensator is designed to suppress vibrations (multiple modes with a broad band of frequencies) of a circular plate with Kelvin-Voigt damping and clamped boundary conditions. The control is realized via piezoceramic patches bonded to the plate and is calculated from information available from several pointwise observed state variables. Examples from computational studies as well as use in laboratory experiments are presented to demonstrate the effectiveness of this design.

  10. Proceedings of the 2nd Workshop on Awareness and Reflection in Technology-Enhanced Learning

    OpenAIRE

    Moore, Adam; Pammer, Viktoria; Pannese, Lucia; Prilla, Michael; Rajagopal, Kamakshi; Reinhardt, Wolfgang; Ullman, Thomas; Voigt, Christian

    2013-01-01

    Moore, A., Pammer, V., Pannese, L., Prilla, M., Rajagopal, K., Reinhardt, W., Ullman, Th. D., & Voigt, Ch. (Eds.) (2012). Proceedings of the 2nd Workshop on Awareness and Reflection in Technology Enhanced Learning. In conjunction with the 7th European Conference on Technology Enhanced Learning: 21st Century Learning for 21st Century Skills (ARTEL/EC-TEL 2012). September, 18, 2012, Saarbrücken, Germany. Available online at http://ceur-ws.org/Vol-931/.

  11. Wave-Sediment Interaction in Muddy Environments: A Field Experiment

    Science.gov (United States)

    2009-01-01

    Liu, 1987), generalized Voigt solids (Jiang and Mehta, 1995; Jiang and Mehta, 1996), and non-Newtonian fluids (Chou et al., 1993; Foda et al., 1993...dissipation is significantly stronger (Gade, 1957; Chou et al., 1993; Foda et al., 1993). On the other hand, even under mildly energetic waves mud...state can change from consolidated to fluid over the duration of one storm (Chou et al., 1993; Foda et al., 1993; also deWitt, 1995). The similar

  12. Dispersion regions overlapping for bulk and surface polaritons in a magnetic-semiconductor superlattice

    CERN Document Server

    Fesenko, Volodymyr I; Tuz, Vladimir R

    2016-01-01

    Extraordinary dispersion features of both bulk and surface polaritons in a finely-stratified magnetic-semiconductor structure which is under an action of an external static magnetic field in the Voigt geometry are discussed in this letter. It is shown that the conditions for total overlapping dispersion regions of simultaneous existence of bulk and surface polaritons can be reached providing a conscious choice of the constitutive parameters and material fractions for both magnetic and semiconductor subsystems.

  13. Closed-Loop Resuscitation of Hemorrhagic Shock

    Science.gov (United States)

    2011-02-21

    of care arterial blood pressure. We collected data from hemorrhaged sheep experiments (funded by this ONR grant), and from a series of hemorrhaged...ongoing, and is the focus of engineering graduate student Ben Voigt. 9) We continued close collaborations with the Institute of Surgical Research on...finger), and pigs (tail). This provides the opportunity to perform testing in reproducible animal models. CareTaker will have to be tested in patients

  14. Hybrid Soft Soil Tire Model (HSSTM). Part 1: Tire Material and Structure Modeling

    Science.gov (United States)

    2015-04-28

    HYBRID SOFT SOIL TIRE MODEL (HSSTM). PART I: TIRE MATERIAL AND STRUCTURE MODELING Taheri, Sh.a,1, Sandu, C.a...model the dynamic behavior of the tire on soft soil , a lumped mass discretized tire model using Kelvin-Voigt elements is developed. To optimize the...terrains (such as sandy loam) and tire force and moments, soil sinkage, and tire deformation data were collected for various case studies based on a

  15. Tissue elasticity properties as biomarkers for prostate cancer

    OpenAIRE

    Hoyt, Kenneth; Castaneda, Benjamin; Zhang, Man; Nigwekar, Priya; di Sant’Agnese, P.Anthony; Joseph, Jean V.; Strang, John; Rubens, Deborah J.; Parker, Kevin J.

    2008-01-01

    In this paper we evaluate tissue elasticity as a longstanding but qualitative biomarker for prostate cancer and sonoelastography as an emerging imaging tool for providing qualitative and quantitative measurements of prostate tissue stiffness. A Kelvin-Voigt Fractional Derivative (KVFD) viscoelastic model was used to characterize mechanical stress relaxation data measured from human prostate tissue samples. Mechanical testing results revealed that the viscosity parameter for cancerous prostate...

  16. Signal Processing for Fibre-optic Distributed Sensing Techniques Employing Brillouin Scattering

    Institute of Scientific and Technical Information of China (English)

    XIAO Shang-hui; LI Li

    2009-01-01

    As fibre optic distributed scattering sensing systems are providing innovative solutions for the monitoring of large structures, Brillouin-based distributed scattering sensing techniques represent a new physical approach for structures health monitoring, which seems extremely promising and is receiving most attentions. This paper comprehensively presents some methods of signal interrogation for fibre optic Brillouin-based distributed scattering sensing technology, especially establishes an accurate Pseudo-Voigt model of Brillouin gain spectrum and gives some results on spectrum analysis and data processing.

  17. Investigation of magneto-optical effects on properties of surface modes in one dimensional magnetized plasma photonic crystals

    Science.gov (United States)

    Shukla, Shikha; Prasad, Surendra; Singh, Vivek

    2016-09-01

    We have studied the properties of surface modes on one dimensional magnetized plasma photonic crystals in two configurations: Faraday and Voigt configurations. The results have been demonstrated by using the transfer matrix method and employing boundary conditions for TE and TM modes, respectively. For the Voigt effect, only the TM mode is considered because the TE modes under the influence of external magnetic field have the same properties as un-magnetized plasma. The influence of external magnetic field has been studied for three cases, i.e., TE left circular polarization, TE right circular polarization, and TM surface modes. It is shown that the properties of surface modes can be tuned correspondingly by changing the cap layer thickness, wave vector, and external magnetic field in the desired photonic band gap. The results show that collision frequency has a negligible effect on surface modes. A new type of wave called Fano mode has been reported for the Voigt effect for the TM mode in the first band gap. Proof of its existence has been demonstrated in the present paper.

  18. Experimental and Theoretical He-BROADENED Line Parameters of Carbon Monoxide in the Fundamental Band

    Science.gov (United States)

    Predoi-Cross, Adriana; Rosario, Hoimonti; Esteki, Koorosh; Latif, Shamria; Naseri, Hossein; Thibault, Franck; Devi, V. Malathy; Smith, Mary Ann H.; Mantz, Arlan

    2016-06-01

    We report experimental measurements and theoretical calculations for He-broadened Lorentz half-width coefficients and He- pressure-shift coefficients of 45 carbon monoxide transitions in the 1-0 band. The high-resolution spectra analyzed in this study were recorded over a range of sample temperatures between 296 and 80 K. The He-broadened line parameters and their temperature dependences were retrieved using a multispectrum nonlinear least squares analysis program. A previous analysis of these spectra used only the Voigt line shape. In the present study four line shape models were compared including Voigt, speed dependent Voigt, Rautian (to take into account confinement narrowing) and Rautian with speed dependence. The line mixing coefficients have been calculated using the Exponential Power Gap scaling law. We were unable to retrieve the temperature dependence of the line mixing coefficients. The current measurements and theoretical results are compared with other published results, where appropriate. A. W. Mantz et al., J. Molec. Structure 742 (2005) 99-110

  19. Evaluating Bounds and Estimators for Constants of Random Polycrystals Composed of Orthotropic Elastic Materials

    Energy Technology Data Exchange (ETDEWEB)

    Berryman, J. G.

    2012-03-01

    While the well-known Voigt and Reuss (VR) bounds, and the Voigt-Reuss-Hill (VRH) elastic constant estimators for random polycrystals are all straightforwardly calculated once the elastic constants of anisotropic crystals are known, the Hashin-Shtrikman (HS) bounds and related self-consistent (SC) estimators for the same constants are, by comparison, more difficult to compute. Recent work has shown how to simplify (to some extent) these harder to compute HS bounds and SC estimators. An overview and analysis of a subsampling of these results is presented here with the main point being to show whether or not this extra work (i.e., in calculating both the HS bounds and the SC estimates) does provide added value since, in particular, the VRH estimators often do not fall within the HS bounds, while the SC estimators (for good reasons) have always been found to do so. The quantitative differences between the SC and the VRH estimators in the eight cases considered are often quite small however, being on the order of ±1%. These quantitative results hold true even though these polycrystal Voigt-Reuss-Hill estimators more typically (but not always) fall outside the Hashin-Shtrikman bounds, while the self-consistent estimators always fall inside (or on the boundaries of) these same bounds.

  20. HELIOS-K: An Ultrafast, Open-source Opacity Calculator for Radiative Transfer

    CERN Document Server

    Grimm, Simon L

    2015-01-01

    We present an ultrafast opacity calculator for application to exoplanetary atmospheres, which we name HELIOS-K. It takes a line list as an input, computes the shape of each spectral line (e.g., a Voigt profile) and provides an option for grouping an enormous number of lines into a manageable number of bins. We implement a combination of Algorithm 916 and Gauss-Hermite quadrature to compute the Voigt profile, write the code in CUDA and optimise the computation for graphics processing units (GPUs). We use the k-distribution method to reduce $\\sim 10^5$ to $10^8$ lines to $\\sim 10$ to $10^4$ wavenumber bins, which may then be used for radiative transfer, atmospheric retrieval and general circulation models. We demonstrate that the resampling of the k-distribution function, within each bin, is an insignificant source of error across a broad range of wavenumbers and column masses. By contrast, the choice of line-wing cutoff for the Voigt profile is a significant source of error and affects the value of the compute...

  1. Connecting the grain-shearing mechanism of wave propagation in marine sediments to fractional calculus

    CERN Document Server

    Pandey, Vikash

    2015-01-01

    An analogy is drawn between the diffusion-wave equations derived from the fractional Kelvin-Voigt model and those obtained from Buckingham's grain-shearing (GS) model [J. Acoust. Soc. Am. 108, 2796-2815 (2000)] of wave propagation in saturated, unconsolidated granular materials. The material impulse response function from the GS model is found to be similar to the power-law memory kernel which is inherent in the framework of fractional calculus. The compressional wave equation and shear wave equation derived from the GS model turn out to be the Kelvin-Voigt fractional-derivative wave equation and the fractional diffusion-wave equation respectively. Also, a physical interpretation of the characteristic fractional-order present in the Kelvin-Voigt fractional derivative wave equation and time-fractional diffusion-wave equation is inferred from the GS model. The shear wave equation from the GS model predicts both diffusion and wave propagation in the fractional framework. The overall goal is intended to show that...

  2. Trans-identity - the Standards of Diagnostics and Treatment

    Directory of Open Access Journals (Sweden)

    Gessmann H.-V.

    2014-11-01

    Full Text Available German Society for Sexual Research, Academy of Sexual Medicine and Society of Sexology formulated standards for evaluation and treatment of transsexuals. The creation of the standards involved Sophinette Becker, Hartmut A. G. Bosinski, Ulrich Clement, Wolf Eicher, Thomas M. Goerlich, Uwe Hartmann, Götz Kockott, Dieter Langer, Wilhelm E. Preuss, Gunter Schmidt, Alfred Springer, Reinhard Wille. Since 1980, the Federal Republic of Germany has a law on transsexualism, which regulates the right of the individual to change the sex. However, until now there were no specifically defined standards of assessment and treatment of transsexuals. For the first time, in 1979 Harry Benjamin invited the International Medical Association of Germany to revise the standards of medical care for gender dysphoria. The following standards of assessment and treatment of transsexuals have been developed at a conference convened by the German Society for Research Expert Committee under the leadership of Sophinette Becker. The review of currently valid standards for evaluation and treatment of transgender is the subject of this article

  3. Denis Guedj at CERN

    CERN Multimedia

    2009-01-01

    Denis Guedj (right), pictured with Etiennette Auffray Hillemanns of the CMS collaboration and Hartmut Hillemanns of the DG-KTT group.French author Denis Guedj, who is also a mathematician and Professor of History of Science at Paris VIII University, visited CERN on 7 and 8 October. During a presentation in the CERN Library he discussed his 15 published books and likened the process of novel writing to working on a scientific experiment: it begins with a limited amount of data, and then questions arise, problems are solved and further research reveals truths. Denis Guedj works hard to ensure that his novels contain ‘true fiction’. His most recent visit to CERN will help him to write a new book set at the LHC in which he will combine his scientific interest in what happens when a proton and proton collide with a human story about what happens to a male and female physicist who meet in the LHC tunnel. "Visiting the CMS cavern was...

  4. Test of Lorentz symmetry with trapped ions

    Science.gov (United States)

    Pruttivarasin, Thaned

    2016-05-01

    The outcome of an experiment should not depend on the orientation of the apparatus in space. This important cornerstone of physics is deeply engrained into the Standard Model of Physics by requiring that all fields must be Lorentz invariant. However, it is well-known that the Standard Model is incomplete. Some theories conjecture that at the Planck scale Lorentz symmetry might be broken and measurable at experimentally accessible energy scales. Therefore, a search for violation of Lorentz symmetry directly probes physics beyond the Standard model. We present a novel experiment utilizing trapped calcium ions as a direct probe of Lorentz-violation in the electron-photon sector. We monitor the energy between atomic states with different orientations of the electronic wave-functions as they rotate together with the motion of the Earth. This is analogous to the famous Michelson-Morley experiment. To remove magnetic field noise, we perform the experiment with the ions prepared in the decoherence-free states. Our result improves on the most stringent bounds on Lorentz symmetry for electrons by 100 times. The experimental scheme is readily applicable to many ion species, hence opening up paths toward much improved test of Lorentz symmetry in the future. (Ph. D. Advisor: Hartmut Haeffner, University of California, Berkeley).

  5. Rationing in Medicine: A Presupposition for Humanity and Justice

    Directory of Open Access Journals (Sweden)

    Gundolf Gubernatis

    2009-01-01

    Full Text Available Limited resources are the permanent condition in health care. Rationing, according to H. Kliemt, is the distribution of limited resources below market prices to all people in need for these resources. Therefore, rationing is a basic component of every kind of human health care system. However, the crucial problem is how to find just and fair rules for this distribution under the premise, that every patient should have the same chance. The allocation of organs for transplant can serve as a paradigmatic example for studying rationing problems, as shortage of organs cannot be denied nor abolished. H. Kliemt compared the situation with the classic decathlon. The selection of factors and the combination and weighing of these factors for 'winning a donor organ' should strictly be related to individuals. Non-medical criteria should generally be accepted and authorized as far as they are relevant to the question of justice and fairness. In this paper the so-called 'solidarity model', an example of joint research with Hartmut Kliemt, is introduced as an allocation system with the power to enhance justice and fairness.

  6. Atmospheric and aerosol chemistry

    Energy Technology Data Exchange (ETDEWEB)

    McNeill, V. Faye [Columbia Univ., New York, NY (United States). Dept. of Chemical Engineering; Ariya, Parisa A. (ed.) [McGill Univ. Montreal, QC (Canada). Dept. of Chemistry; McGill Univ. Montreal, QC (Canada). Dept. of Atmospheric and Oceanic Sciences

    2014-09-01

    This series presents critical reviews of the present position and future trends in modern chemical research. Short and concise reports on chemistry, each written by the world renowned experts. Still valid and useful after 5 or 10 years. More information as well as the electronic version of the whole content available at: springerlink.com. Christian George, Barbara D'Anna, Hartmut Herrmann, Christian Weller, Veronica Vaida, D. J. Donaldson, Thorsten Bartels-Rausch, Markus Ammann Emerging Areas in Atmospheric Photochemistry. Lisa Whalley, Daniel Stone, Dwayne Heard New Insights into the Tropospheric Oxidation of Isoprene: Combining Field Measurements, Laboratory Studies, Chemical Modelling and Quantum Theory. Neil M. Donahue, Allen L. Robinson, Erica R. Trump, Ilona Riipinen, Jesse H. Kroll Volatility and Aging of Atmospheric Organic Aerosol. P. A. Ariya, G. Kos, R. Mortazavi, E. D. Hudson, V. Kanthasamy, N. Eltouny, J. Sun, C. Wilde Bio-Organic Materials in the Atmosphere and Snow: Measurement and Characterization V. Faye McNeill, Neha Sareen, Allison N. Schwier Surface-Active Organics in Atmospheric Aerosols.

  7. Generalized encoding and decoding operators for lattice-based associative memories.

    Science.gov (United States)

    McElroy, John; Gader, Paul

    2009-10-01

    During the 1990s Ritter, introduced a new family of associative memories based on lattice algebra instead of linear algebra. These memories provide unlimited storage capacity, unlike linear-correlation-based models. The canonical lattice-based memories, however, are susceptible to noise in the initial input data. In this brief, we present novel methods of encoding and decoding lattice-based memories using two families of ordered weighted average (OWA) operators. The result is a greater robustness to distortion in the initial input data, and a greater understanding of the effect of the choice of encoding and decoding operators on the behavior of the system, with the tradeoff that the time complexity for encoding is increased.

  8. STOCK MARKET WEALTH-EFFECTS DURING PRIVATIZATION INITIAL PUBLIC OFFERS IN CHILE (1984-1989

    Directory of Open Access Journals (Sweden)

    ROBERTO J. SANTILLÁN SALGADO

    2010-01-01

    económicas y políticas prevalecientes. En particular, se presentan los detalles operativos del mecanismo de emisión de acciones, complementado con un estudio estadístico de los Rendimientos Ajustados por el Mercado de las OPIs. Aunque el tamaño de la muestra es limitado y no permite alcanzar una validez externa, el análisis confirma la presencia de patrones de desempeño muy similares a los observados en OPIs tanto privadas como privatizadoras, de acuerdo con otros estudios relacionados (Aggarwal, Leal y Hernández, 1993; Dewenter y Malatesta, 1997; Loughran, Ritter y Rydqvist, 1994; Perotti y Guney, 1993.

  9. Alkalithermophilic actinomycetes in a subtropical area of Jujuy, Argentina.

    Science.gov (United States)

    Carrillo, L; Benítez Ahrendts, M R; Maldonado, M J

    2009-01-01

    The objective of this study was to examine the alkalithermophilic actinomycete communities in the subtropical environment of Jujuy, Argentina, characterized by sugarcane crops. Laceyella putida, Laceyella sacchari, Thermoactinomyces intermedius, Thermoactinomyces vulgaris and Thermoflavimicrobium dichotomicum were isolated on the media with novobiocin, from sugar cane plants and renewal rhizospheres, and grass and wood soils. Soil pH was almost neutral or lightly alkaline, except for grass soil acidified by lactic liquor. A smaller number of actinomycetes was found on the living plants and bagasse (recently obtained or stored according to the Ritter method) with respect to decomposed leaves on the soil. Thermophilic species of Laceyella, Thermoactinomyces, Thermoflavimicrobium, Saccharomonospora, Streptomyces and Thermononospora were isolated on the media without novobiocin, from composted sugar cane residues. Air captured near composted bagasse piles, contained alkalithermophilic actinomycete spores.

  10. "Oasis de neblina" en los cerros costeros del sur de Iquique, región de Tarapacá, Chile, durante el evento El Niño 1997-1998 Fog oases during the El Niño Southern Oscillation 1997-1998, in the coastal hills south of Iquique, Tarapacá region, Chile

    Directory of Open Access Journals (Sweden)

    MÉLICA MUÑOZ-SCHICK

    2001-06-01

    Full Text Available Se describe la flora de cuatro sitios de "oasis de neblina" del desierto costero del Norte de Chile, entre Iquique y la desembocadura del río Loa, muestreados entre los meses de octubre de 1997 y enero de 1998. No existían muestreos anteriores en tres de los sitios: Alto Patache, Punta Lobos y Alto Chipana. Se registraron en esta ocasión 72 especies de plantas vasculares, lo que amplía notablemente el conocimiento florístico de este sector, que poseía a la fecha apenas una veintena de especies registradas. De las especies recolectadas, tres constituyen nuevos registros para la flora chilena: Nolana adansonii (Roem. et Schult. Johnst., Solanum cfr. montanum L. y Ophryosporus cfr. floribundus (DC. King et Rob., mientras que Alstroemeria lutea (Muñoz 2000 constituye una especie nueva para la ciencia. Esta última, junto a Eulychnia aricensis Ritter, Pyrrhocactus saxifragus Ritter y Nolana intonsa Johnst., son endémicas locales. Del total de especies, un 43 % son endémicas y un 52,8 % son nativas no endémicas, existiendo un bajo porcentaje (4,2 % de especies adventicias; 34 especies (47,2 % comparten su área de distribución con el Perú. Las familias Asteraceae, Nolanaceae y Solanaceae son las mejor representadas en el área con más de siete especies cada una. Las condiciones climáticas derivadas del evento El Niño 1997-1998 han favorecido el desarrollo de la vegetación en los oasis de neblina al sur de Iquique. Aunque no hay un aumento de las precipitaciones durante el período 1997-1998, sí se aprecia un incremento en las temperaturas así como en el contenido líquido de la neblina, lo que favorecería el desarrollo de una vegetación más exuberante y la expansión del área de ocupación de algunos elementos florísticosThe flora of four fog oases in the northern Chilean coastal desert, visited between October 1997 and January 1998, is described. These botanical collections are new for Alto Patache, Punta Lobos and Alto Chipana

  11. EFECTO ANTAGÓNICO DE Zymomonas mobillis spp. FRENTE A Salmonella sp. y Proteus mirabi/is

    Directory of Open Access Journals (Sweden)

    Claudia M. Maldonado

    2001-12-01

    Full Text Available Se emplearon dos métodos microbiológicos para estudiar el antagonismo de 5 cepas de Zymomonas mobilis spp., frente a Proteus mirabilis y Salmonella sp. el método clásico de Ritter y el método ecométrico modificado. En el presente trabajo se demostró el efecto antagónico de· Zymomonas mobilis 560, Zymomonas mobilis mobilis 1 y Zymomonas mobilis pomaceae 1 al inhibir el crecimiento de Proteus mirabilis y Salmonella sp.; antagonismo que fue corroborado con el método ecométrico modificado; en el cual valores de ICA inferiores a 2 alternaban con halos de inhibición que oscilaban entre los 3 y 10 mm de diámetro.

  12. Removal properties of low-thermal-expansion materials with rotating-sphere elastic emission machining

    Directory of Open Access Journals (Sweden)

    Masahiko Kanaoka et al

    2007-01-01

    Full Text Available Optical mirrors used in extreme ultraviolet lithography systems require a figure accuracy and a roughness of about 0.1 nm rms. In addition, mirror substrates must be low-thermal-expansion materials. Thus, in this study, we processed two low-thermal-expansion materials, ULE [K. Hrdina, B. Hanson, P. Fenn, R. Sabia, Proc. SPIE 4688 (2002 454.] (Corning Inc. and Zerodur [I. Mitra, M.J. Davis, J. Alkemper, Rolf Müller, H. Kohlmann, L. Aschke, E. Mörsen, S. Ritter, H. Hack, W. Pannhorst, Proc. SPIE 4688 (2002 462.] (SCHOTT AG, with elastic emission machining (EEM in order to evaluate the removal properties. Consequently, we successfully calculated the respective removal rates, because removal volumes were found to be proportional to process times in EEM. Moreover, we demonstrated that the surface roughness of Zerodur is reduced to 0.1 nm rms in the spatial wavelength range from 100 μm to 1 mm.

  13. 新型Ultem*树脂提升医疗用品藤化学及耐高温性能

    Institute of Scientific and Technical Information of China (English)

    爱德曼

    2010-01-01

    德国实验室器具和医疗用品制造商Ritter GmbH凭借获奖的1Polysteribox消毒和运输容器在竞争中脱颖而出。这些容器采用沙伯基础创新塑料新型Ultem聚醚酰亚胺(PEI)医疗保健规格的树脂制成。考虑到患者的安全性,可重复使用的医疗设备对化学清洗和高压消毒的要求日趋提高,这就需要制造商找到能够经受更强碱性和更高温度的新材料。

  14. Analytical invariant manifolds near unstable points and the structure of chaos

    CERN Document Server

    Efthymiopoulos, C; Katsanikas, M

    2014-01-01

    It is known that the asymptotic invariant manifolds around an unstable periodic orbit in conservative systems can be represented by convergent series (Cherry 1926, Moser 1956, 1958, Giorgilli 2001). The unstable and stable manifolds intersect at an infinity of homoclinic points, generating a complicated homoclinic tangle. In the case of simple mappings it was found (Da Silva Ritter et al. 1987) that the domain of convergence of the formal series extends to infinity along the invariant manifolds. This allows in practice to study the homoclinic tangle using only series. However in the case of Hamiltonian systems, or mappings with a finite analyticity domain,the convergence of the series along the asymptotic manifolds is also finite. Here, we provide numerical indications that the convergence does not reach any homoclinic points. We discuss in detail the convergence problem in various cases and we find the degree of approximation of the analytical invariant manifolds to the real (numerical) manifolds as i) the o...

  15. Anti-Bacterial and Anti-Fungal Activity of Xanthones Obtained via Semi-Synthetic Modification of α-Mangostin from Garcinia mangostana

    Directory of Open Access Journals (Sweden)

    Srinivasan Narasimhan

    2017-02-01

    Full Text Available The microbial contamination in food packaging has been a major concern that has paved the way to search for novel, natural anti-microbial agents, such as modified α-mangostin. In the present study, twelve synthetic analogs were obtained through semi-synthetic modification of α-mangostin by Ritter reaction, reduction by palladium-carbon (Pd-C, alkylation, and acetylation. The evaluation of the anti-microbial potential of the synthetic analogs showed higher bactericidal activity than the parent molecule. The anti-microbial studies proved that I E showed high anti-bacterial activity whereas I I showed the highest anti-fungal activity. Due to their microbicidal potential, modified α-mangostin derivatives could be utilized as active anti-microbial agents in materials for the biomedical and food industry.

  16. Multipurpose microcontroller design for PUGAS 2

    Science.gov (United States)

    Weber, David M.; Deckard, Todd W.

    1987-01-01

    This paper will report on the past year's work on the development of the microcontroller design for the second Purdue University small self-contained payload. A first report on this effort was given at last year's conference by Ritter (1985). At that time, the project was still at the conceptual stage. Now a specific design has been set, prototyping has begun, and layout of the two-sided circuit board using CAD-techniques is nearing completion. A redesign of the overall concept of the circuit board was done to take advantage of the facilities available to students. An additional controller has been added to take large quantities of data concerning the shuttle environment during takeoff. The importance of setting a design time-line is discussed along with the electrical design considerations given to the controllers.

  17. [Phenomenological anthropological social psychiatry--paving the way for a theoretical reanimation].

    Science.gov (United States)

    Thoma, Samuel

    2012-11-01

    This article tries to link the present lack of theoretical discussion within German Social Psychiatry with a loss of phenomenological and anthropological thought. The so-called Phenomenological Psychiatry used to play a very important role in German psychiatry during the 50 ies until the 70 ies and had strong influences on the first reformers of German psychiatry, such as Walter Ritter von Baeyer, Heinz Häfner, Caspar Kulenkampff, Karl Peter Kisker and Erich Wulff. Their reforms were not only founded by a social criticism put forth by theories such as marxism (Basaglia, Wulff) or structuralism (Foucault) but also by a concrete notion of what it is like to suffer from mental illness and what kind of needs are linked to such suffering. This very notion was given by the phenomenological approach. Finally the article tries to give reasons for today's reciprocal loss of connection of the phenomenological and the socio-psychiatric school.

  18. Featuring animacy

    Directory of Open Access Journals (Sweden)

    Elizabeth Ritter

    2015-01-01

    Full Text Available Algonquian languages are famous for their animacy-based grammatical properties—an animacy based noun classification system and direct/inverse system which gives rise to animacy hierarchy effects in the determination of verb agreement. In this paper I provide new evidence for the proposal that the distinctive properties of these languages is due to the use of participant-based features, rather than spatio-temporal ones, for both nominal and verbal functional categories (Ritter & Wiltschko 2009, 2014. Building on Wiltschko (2012, I develop a formal treatment of the Blackfoot aspectual system that assumes a category Inner Aspect (cf. MacDonald 2008, Travis 1991, 2010. Focusing on lexical aspect in Blackfoot, I demonstrate that the classification of both nouns (Seinsarten and verbs (Aktionsarten is based on animacy, rather than boundedness, resulting in a strikingly different aspectual system for both categories. 

  19. Scalded skin syndrome: Diagnosis, differential diagnosis, and management of 42 children.

    Science.gov (United States)

    Margileth, A M

    1975-04-01

    The bacteriologic, epidemiologic, clinical, and diagnostic findings and management of the scalded skin syndrome (SSS) in 42 children are reported SSS may present in one of three ways: (1) Ritter's disease in infants, characterized by an acute, generalized bullous dermatitis simulating the appearance of scalded skin, followed by exfoliation; (2) Lyell's disease, or toxic epidermal necrolysis (TEN), in children or adults, with scalded skin and bullae followed by extensive exfoliation; or (3) a nonstreptococcal scarlatiniform eruption, or staphylococcal scarlet fever, manifested by a generalized scarlatiniform erythema ans subsequent minimal to moderate fine desquamation. Staphylococcus aureus was isolated and implicated as the causative agent in 32 of the 42 children; nine of the other ten children had received a drug or vaccine preceding their rash. SSS in children has increased in frequency recently, is usually due to S aureus infection with potential epidemic aspects, can be recognized easily by its unusual clinical features, and has an excellent prognosis with appropriate management.

  20. Exemplary subsurface geothermal projects in the western part of Germany; Beispiele zur Nutzung oberflaechennaher Geothermie im Westen Deutschlands

    Energy Technology Data Exchange (ETDEWEB)

    Sanner, B.; Mands, E. [UbeG GbR, Wetzlar (Germany); Kohlsch, O. [EWS Erdwaerme-Systemtechnik GmbH, Delbrueck (Germany)

    2004-12-01

    During the past few years, several projects involving ground source heat pumps were carried out in western Germany, especially in the Rhine-Main and Rhine-Ruhr-Sieg region including the cities of Frankfurt and Cologne. Some of the project partners are big names in industry, e.g. an office building of PhilipsSparte APD at Wetzlar and the museum building of chocolate producer Ritter Sport. Other projects are sited in rural regions, from the Black Forest to the Weserbergland hills. The contribution presents several interesting projects, e.g. the police headquarters building at Bonn (right bank, groundwater use) and the office building of the Federal Office of Environmental protection, also at Bonn (left bank, geothermal probles), and three school buildings in the Frankfurt/Main region at Glashuetten, Bad Homburg-Oberstedten and Usingen-Eschbach. (orig.) [German] In den letzten Jahren wurden im Westen Deutschlands eine ganze Reihe groesserer Projekte mit erdgekoppelten Waermepumpen verwirklicht, besonders im Rhein-Main-Gebiet und im Rhein-Ruhr-Sieg-Gebiet einschliesslich der Grossstaedte Frankfurt und Koeln. Zu den Bauherren zaehlen inzwischen auch bekannte Namen der deutschen Industrie. So wird in Wetzlar ein Buerogbaeude der PhilipsSparte APD mit Erdwaermesonden ausgeruestet, und das Museum des Schokoladenherstellers Ritter Sport wird auf Energiepfaehlen stehen. Abe auch im laendlichen Raum sind interessante Anlagen entstanden, vom Schwarzwald bis ins Weserbergland. Im Folgenden werden einige interessante Beispiele vorgestellt. Dabei sind Projekte in der Ausfuehrungsphase wie z.B. das Polizeipraesidium in Bonn (rechts des Rheins mit Grundwassernutzung), oder das Bundesamt fuer Naturschutz in Bonn, diesmal auf der linken Rheinseite und mit Erdwaermesonden. In Ausfuehrungn bzw. fertiggestellt sind auch Erdwaermesonden fuer 3 Schulen im Raum Frankfurt:/Main, in Glashuetten, Bad Homburg-Oberstedten und Usingen-Eschbach. (orig.)

  1. High-velocity Hα Absorption Events in B8 Ia - A2 Ia Supergiant Stars

    Science.gov (United States)

    Morrison, Nancy D.; Markova, N.; Rother, S. J.

    2009-12-01

    Late B- and early A-type supergiants are notorious for the time variability of their Hα line profiles, but the physical cause of the variations is poorly understood. Usually, the line is filled in by emission, and the blue absorption wing does not extend to the terminal wind speed, which is roughly defined by the blue edges of the ultraviolet resonance lines. On rare occasions, however, the blue wing of Hα goes strongly into absorption over a wide velocity range, from the photospheric velocity almost all the way to the terminal wind speed. This phenomenon was first described by Kaufer et al. (1996, A&A, 314, 599), who denoted it by the term, "High-Velocity Absorption Event." In this report, high-resolution spectra from Ritter Observatory will be combined with published spectra to examine the temporal recurrence behavior and strength distribution of high-velocity absorption events and their incidence as a function of stellar parameters for the available sample of stars. All B8- and A0-type, Ia-class, stars in the sample that have been sufficiently well observed, as well as one A2-type star, show the events. However, there is some evidence that hyperluminous stars (luminosity class Ia+) do not show the events. In one of the most extensively observed stars in the sample (Rigel, B8 Ia), there is no clear periodicity in the recurrence times of the events. In addition to the strong events discovered by Kaufer et al. (1996), there is a broad distribution of more frequent, weaker events. Ritter Observatory receives operating support from the National Science Foundation Program for Research and Education with Small Telescopes (PREST) award AST-0440784.

  2. Long-term Spectroscopic Monitoring Of Rigel (alpha Ori, B8ia)

    Science.gov (United States)

    Morrison, Nancy D.; Rother, S.

    2010-01-01

    Rigel is a massive blue supergiant star with a radiation-driven stellar wind. Its H alpha line profile is known to be strongly variable, for reasons that are poorly understood. Our observational data consist of 192 echelle spectra (R = 26,000) taken over the course of 10 seasons with the 1.1-m telescope of The University of Toledo's Ritter Observatory. The H alpha profiles were classified into morphological categories, such as P Cygni, double-peaked, inverse P Cygni, pure absorption, pure emission, etc., and the frequency of occurrence of each category computed. Radial velocities of C II 6578, 6582 and of the absorption and emission components of H alpha were measured. In 2006, we observed a high-velocity H alpha absorption event, similar to those observed in this star in 1993 and 1994 by Kaufer et al. (1996, A&A, 314, 599). As Israelian et al. (1997, MNRAS, 290, 521) found during the 1993 event, we found possible evidence for infalling material in the aftermath of the 2006 event. The observations rule out periodicity in the occurrence of these major absorption events, but numerous minor enhancements in the blue absorption wing of H alpha were observed at apparently random times. A preliminary period search of the whole data set with the IRAF implementation of PDM yielded no periodicity in the radial velocities. A more detailed time-series analysis is planned. These results indicate that, as other authors have also pointed out, the wind of this star is inhomogeneous and irregular. This research was partially supported by NSF-PREST award AST-0440784. During the time frame of these observations, Ritter Observatory received support from the Fund for Astrophysical Research and the American Astronomical Society Small Grants Program.

  3. Mesospheric turbulence detection and characterization with AMISR-class radars under consistent meteorological conditions

    Science.gov (United States)

    Li, J.; Collins, R. L.; Newman, D.; Nicolls, M. J.; Varney, R. H.; Thurairajah, B.

    2015-12-01

    A recent study has shown the ability of the Advanced Modular Incoherent Scatter Radar (AMISR) at Poker Flat Research Range (PFRR, PFISR) to characterize turbulence in the mesosphere (D-Region) [Nicolls et. al, 2011]. We present case studies of AMISR measurements of turbulence where the meteorological conditions are defined by the presence of persistent Mesospheric Inversion Layers (MILs). We consider MILs that are detected by satellite over a day and are also detected by Rayleigh lidar at PFRR [Irving et. al, 2014]. MILs are a signature of large-scale planetary wave breaking in the upper atmosphere, where a region with a temperature inversion lies below a region with an adiabatic lapse rate. The region with the inversion allows small-scale waves to become unstable, break, and generate turbulence. The region with the adiabatic lapse rate is indicative of a well-mixed layer and the presence of turbulence. AMISR-class radars have a steerable narrow beam (1°) and high vertical resolution (750 m). We review the principles and practices of incoherent scatter radar with a focus on detection of D-region turbulence using radar spectra. We present the geometry of the turbulence and the radar, comparing the turbulent, plasma, and radar spatial scales. We develop a turbulence retrieval algorithm using a Voigt function spectral line. We fit the spectra to a Voigt function using the Levenberg-Marquardt method and use the Gaussian component of the Voigt spectra to calculate the RMS velocity, and hence the turbulent energy dissipation rate. With the environmental conditions characterized by satellite and lidar and the turbulence characterized by radar data, we can test the ability of PFISR to characterize mesospheric turbulence under consistent meteorological conditions and develop robust technique for turbulence measurements.

  4. Superconductivity Technology Program for electric power systems: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, K.B.

    1993-09-01

    Twenty-seven presentations are included in viewgraph form for the wire development panel, applications development panel, and thallium workshop. Authors and affiliations are: (wire development panel) Kreoger/Christen (ORNL), Malozemoff (American Superconductor Corp.), Blaugher (National Renewable Energy Lab.), Haldar (Intermagnetics), Gray/Lanagan/Eror (ANL), Bickel/Voigt/Roth (Sandia), Tkaczyk (GE), Suenaga (BNL), Willis/Korzekwa/Maley (Los Alamos); (applications development panel) Peterson/Stewart (Los Alamos), Iwasa (BNL), Hull/Nieman (ANL), Murphy/DeGregoria (ORNL), Hazelton (Intermagnetics), Dykhuizen (Sandia); (thallium workshop) Goodrich (NIST), Blaugher (NREL), Roth (Sandia), Holstein (DuPont), Paranthaman (ORNL), and Willis (Los Alamos).

  5. Broadening of a spectrum line by finite spectrometer resolution. [FORTRAN IV; SAL, KAL

    Energy Technology Data Exchange (ETDEWEB)

    Engleman, R. Jr.

    1978-12-01

    The distortion of a spectrum line by the finite resolving power of a spectrometer is discussed in terms of a mathematical model. Particular attention is given to the case where either a Gaussian or Cauchy slit function broadens an isolated Doppler, Lorentz, or Voigt absorption line. Corrections to the peak absorption, the line width, and the integrated absorption coefficient are calculated and discussed for different combinations of slit functions and line shapes. Several new series expansions for the corrections are derived. Two general FORTRAN IV programs that calculate these corrections are described and some sample correction curves are given. 27 references.

  6. La teoría de la relatividad: ayer y hoy

    OpenAIRE

    Cervantes-Cota, Jorge L.; M.A. Rodríguez-Meza

    2006-01-01

    Explicamos los dos postulados dela teoría de la relatividad especial, poniendo énfasis en los conocimientos científicos históricos detrás de las ideas que empleó el joven Albert Einstein en 1905. El papel de científicos como Maxwell, Michelson, Voigt, Lorentz, Fitzgerald, entre otros, es dilucidado. También explicamos la geometría del nuevo espacio-tiempo que emana de la teoría, así como las consecuencias en la medición del espacio, tiempo y masas de observadores en movimiento relativo. Fina...

  7. A THREE-DIMENSIONAL SOLUTION FOR LAMINATED ORTHOTROPIC RECTANGULAR PLATES WITH VISCOELASTIC INTERFACES

    Institute of Scientific and Technical Information of China (English)

    Yan Wei; Ying Ji; Chen Weiqiu

    2006-01-01

    When a body consists completely or even partly of viscoelastic materials, its response under static loading will be time-dependent. The adhesives used to glue together single plies in laminates usually exhibit a certain viscoelastic characteristic in a high temperature environment. In this paper, a laminated orthotropic rectangular plate with viscoelastic interfaces,described by the Kelvin-Voigt model, is considered. A power series expansion technique is adopted to approximate the time-variation of various field quantities. Results indicate that the response of the laminated plate with viscoelastic interfaces changes remarkably with time, and is much different from that of a plate with spring-like or viscous interfaces.

  8. Loss tangent imaging: Theory and simulations of repulsive-mode tapping atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Proksch, Roger [Asylum Research, Santa Barbara, California 93117 (United States); Yablon, Dalia G. [ExxonMobil Research and Engineering, Annandale, New Jersey (United States)

    2012-02-13

    An expression for loss tangent measurement of a surface in amplitude modulation atomic force microscopy is derived using only the cantilever phase and the normalized cantilever amplitude. This provides a direct measurement of substrate compositional information that only requires tuning of the cantilever resonance to provide quantitative information. Furthermore, the loss tangent expression incorporates both the lost and stored energy into one term that represents a fundamental interpretation of the phase signal in amplitude modulation imaging. Numerical solutions of a cantilever tip interacting with a simple Voigt modeled surface agree with the derived loss tangent to within a few percent.

  9. Investigation of radial temperature gradients in diode pumped alkali lasers using tunable diode laser absorption spectroscopy

    Science.gov (United States)

    Fox, Charles D.; Perram, Glen P.

    2012-03-01

    Heat loads in Diode Pumped Alkali Lasers (DPAL) have been investigated using a diode laser to probe the radial dependence of the absorbance. A TiS pump laser heats the medium in a T=50-100°C cesium heat pipe with 5 Torr nitrogen used for quenching. A tunable diode laser probes the spectral absorbance of the cesium cell. Local alkali concentration, temperature, and saturation broadening modify Voigt lineshapes in the wing of the hyperfine split lines. The temperature within the pumped volume exceeds the wall temperature by almost 200 C.

  10. Notes on continuum mechanics

    CERN Document Server

    Chaves, Eduardo W V

    2013-01-01

    This publication is aimed at students, teachers, and researchers of Continuum Mechanics and focused extensively on stating and developing Initial Boundary Value equations used to solve physical problems. With respect to notation, the tensorial, indicial and Voigt notations have been used indiscriminately.   The book is divided into twelve chapters with the following topics: Tensors, Continuum Kinematics, Stress, The Objectivity of Tensors, The Fundamental Equations of Continuum Mechanics, An Introduction to Constitutive Equations, Linear Elasticity, Hyperelasticity, Plasticity (small and large deformations), Thermoelasticity (small and large deformations), Damage Mechanics (small and large deformations), and An Introduction to Fluids. Moreover, the text is supplemented with over 280 figures, over 100 solved problems, and 130 references.

  11. Michelson Interferometer characterisation of noise reduction in DFB fibre lasers

    Science.gov (United States)

    Canagasabey, Albert; Jones, David; Mann, David; Canning, John; Fleming, Simon; Holdsworth, John

    2012-02-01

    A comparison is made between unpackaged and packaged distributed feedback (DFB) fibre lasers using the Michelson interferometer configuration for delayed self-heterodyne interferometery (MIDSHI) to ascertain the improvements to the external environmental noise, quantified by reductions in the Gaussian linewidth. Voigt fitting is used to extract and separate out the Lorentzian and Gaussian linewidth contributions and therefore the associated sources of noise. Significant improvements in the Gaussian linewidth were achieved as a result of significant reductions in the sensitivity of the DFB laser to external perturbations using packaging. However, a broadening of the laser Lorentzian linewidth was observed.

  12. Tunable surface plasmon-polaritons in a gyroelectric slab sandwiched between two graphene layers

    Science.gov (United States)

    Xu, Guoding; Cao, Ming; Liu, Chang; Sun, Jian; Pan, Tao

    2016-05-01

    We study numerically the properties of surface plasmon-polaritons (SPPs) in a gyroelectric slab sandwiched between two graphene layers, where the external static magnetic field is applied in the Voigt geometry. It is shown that the dispersion characteristics and propagation lenghts of the SPPs for both the optical and the acoustic branches can be tuned flexibly by the external magnetic field and graphene's chemical potential, and that the nonreciprocal properties of the SPPs caused by the external magnetic field are rather obvious. The results provide a method for adjusting and improving the dispersion and propagation properties of the SPPs, which might be helpful for the design of the related plasmonic devices.

  13. A line-broadening analysis model for the microstructural characterization of nanocrystalline materials from asymmetric x-ray diffraction peaks.

    Science.gov (United States)

    Pantoja-Cortés, Juan; Sánchez-Bajo, Florentino; Ortiz, Angel L

    2012-05-30

    Nanograin sizes and crystal lattice microstrains in nanocrystalline materials are typically evaluated from the broadening of their x-ray diffraction (XRD) peaks under the assumption of symmetrical diffraction profiles. Since this assumption is not entirely satisfactory, we formulate a line-broadening analysis model of a single peak that considers explicitly the XRD peak asymmetry. The model is a generalization of the variance method in which the shape of the XRD peaks is idealized through asymmetrical split pseudo-Voigt functions. The model is validated on two nanocrystalline powders.

  14. Single-color, in situ photolithography marking of individual CdTe/ZnTe quantum dots containing a single Mn{sup 2+} ion

    Energy Technology Data Exchange (ETDEWEB)

    Sawicki, K.; Malinowski, F. K.; Gałkowski, K.; Jakubczyk, T.; Kossacki, P.; Pacuski, W.; Suffczyński, J., E-mail: Jan.Suffczynski@fuw.edu.pl [Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5 St., PL-02-093 Warsaw (Poland)

    2015-01-05

    A simple, single-color method for permanent marking of the position of individual self-assembled semiconductor Quantum Dots (QDs) at cryogenic temperatures is reported. The method combines in situ photolithography with standard micro-photoluminescence spectroscopy. Its utility is proven by a systematic magnetooptical study of a single CdTe/ZnTe QD containing a Mn{sup 2+} ion, where a magnetic field of up to 10 T in two orthogonal, Faraday and Voigt, configurations is applied to the same QD. The presented approach can be applied to a wide range of solid state nanoemitters.

  15. Energy density and energy flow of magnetoplasmonic waves on graphene

    Science.gov (United States)

    Moradi, Afshin

    2017-03-01

    By means the linearized magnetohydrodynamic theory, expressions for energy density and energy flow are derived for the p-polarized surface magnetoplasmon polaritons on graphene in the Voigt configuration, where a static magnetic field is normal to the graphene surface. Numerical results show that the external magnetic field has significant impact on the energy density and energy transport velocity of magnetoplasmon waves in the long-wavelength region, while total power flow vary only weakly with magnetostatic field. The velocity of energy propagation is proved to be identical with group velocity of the surface waves.

  16. LQR Control of Shell Vibrations Via Piezoceramic Actuators

    Science.gov (United States)

    delRosario, R. C. H.; Smith, R. C.

    1997-01-01

    A model-based Linear Quadratic Regulator (LQR) method for controlling vibrations in cylindrical shells is presented. Surface-mounted piezo-ceramic patches are employed as actuators which leads to unbounded control input operators. Modified Donnell-Mushtari shell equations incorporating strong or Kelvin-Voigt damping are used to model the system. The model is then abstractly formulated in terms of sesquilinear forms. This provides a framework amenable for proving model well-posedness and convergence of LQR gains using analytic semigroup results combined with LQR theory for unbounded input operators. Finally, numerical examples demonstrating the effectiveness of the method are presented.

  17. Nutritional significance of a winter-flowering succulent for opportunistic avian nectarivores

    CSIR Research Space (South Africa)

    Symes, CT

    2010-01-01

    Full Text Available Pycnonotus nigricans and Cape White-eyes Zosterops capensis. In both these species, the d13C of breath samples was significantly enriched compared with blood and feathers, and closely resembled that of the nectar, revealing combustion of ingested nectar... CO2 (Carleton et al. 2004, 2006, Voigt et al. 2008a, 2008b). Because of the potential for such isotopic routing in birds feeding on A. marlothii nectar, we investigated tissues with differing turnover rates, namely feathers, blood and breath...

  18. Temperature-dependent gelation process in colloidal dispersions by diffusing wave spectroscopy.

    Science.gov (United States)

    Liu, Jiaxue; Boyko, Volodymyr; Yi, Zhiyong; Men, Yongfeng

    2013-11-19

    Temperature-dependent microrheology of a concentrated charge-stabilized poly(methyl methacrylate) colloidal dispersion with different salt concentrations was investigated by diffusing wave spectroscopy in backscattering mode. The critical temperature where the system undergoes aggregation and gelation depends upon the particle volume fraction or salt concentration. The viscoelastic properties of the systems have been discussed using Maxwell and Kelvin-Voigt models. Temperature-dependent crossover (G' = G″) frequency has been used to calculate activation energies representing a critical energy of interaction of gel formation.

  19. Superconductivity Technology Program for electric power systems: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, K.B.

    1993-09-01

    Twenty-seven presentations are included in viewgraph form for the wire development panel, applications development panel, and thallium workshop. Authors and affiliations are: (wire development panel) Kreoger/Christen (ORNL), Malozemoff (American Superconductor Corp.), Blaugher (National Renewable Energy Lab.), Haldar (Intermagnetics), Gray/Lanagan/Eror (ANL), Bickel/Voigt/Roth (Sandia), Tkaczyk (GE), Suenaga (BNL), Willis/Korzekwa/Maley (Los Alamos); (applications development panel) Peterson/Stewart (Los Alamos), Iwasa (BNL), Hull/Nieman (ANL), Murphy/DeGregoria (ORNL), Hazelton (Intermagnetics), Dykhuizen (Sandia); (thallium workshop) Goodrich (NIST), Blaugher (NREL), Roth (Sandia), Holstein (DuPont), Paranthaman (ORNL), and Willis (Los Alamos).

  20. Utilizing Near-IR Tunable Laser Absorption Spectroscopy to Study Detonation and Combustion Systems

    Science.gov (United States)

    2014-03-27

    constant, defined as c2 = hc/k, where h is Planks constant, c is the speed of light, and k is Boltzmann’s constant. The HITEMP database provides values for...and Lorentzian have FWHM of 0.3 cm−1, and the resulting Voigt profile from their convolution has an approximate full width half max of 1.0 cm−1. (a...interpolations (of the mins and maxes ) was considered to be the baseline and was subtracted from the non-smoothed spectrum. This method worked well for

  1. Characterization of Wave Dispersion in Viscoelastic Cellular Assemblies by Doublet Mechanics

    Institute of Scientific and Technical Information of China (English)

    JIN Yan-Fang; XIONG Chun-Yang; FANG Jing; FERRARI Mauro

    2009-01-01

    Using the Voigt model, we analyze wave propagation in viscoelastic granular media with a monatomic lattice, planar simple cubic package and cubical-tetrahedral assembly within the context of doublet mechanics. Microstrains of elongation between the doublet particles are considered in the models. Wave dispersive relations are derived from dynamic equations of the particles involved in the media, and phase velocities and attenuations of the dispersive waves are obtained for the different assemblies. Variations in these dispersion characteristics are analyzed with the changes of cell interval, modulus, and wave frequency. The relations between micro-constants and macro-parameters are presented under the condition of non-scale continuity of the media.

  2. Comment on "Surface electromagnetic wave equations in a warm magnetized quantum plasma" [Phys. Plasmas 21, 072114 (2014)

    Science.gov (United States)

    Moradi, Afshin

    2016-07-01

    In a recent article [C. Li et al., Phys. Plasmas 21, 072114 (2014)], Li et al. studied the propagation of surface waves on a magnetized quantum plasma half-space in the Voigt configuration (in this case, the magnetic field is parallel to the surface but is perpendicular to the direction of propagation). Here, we present a fresh look at the problem and obtain a new form of dispersion relation of surface waves of the system. We find that our new dispersion relation does not agree with the result obtained by Li et al.

  3. Soft-film dynamics of SH-SAW sensors in viscous and viscoelastic fluids

    Directory of Open Access Journals (Sweden)

    A. Vikström

    2016-12-01

    Full Text Available We theoretically investigate surface acoustic waves with horizontal polarization (SH-SAWs propagating in a three-layer system consisting of an elastic substrate and two viscoelastic overlayers. For the limiting case of an acoustically thin middle layer and an infinite top layer, we derive analytical expressions for the phase velocity shift and the wave attenuation. These expressions demonstrate the importance of taking into account the viscoelastic coupling between the two overlayers. Numerical calculations using a combined Maxwell/Voigt scheme confirm our analytical results and also indicate that it is possible for viscoelasticity to cause SH-SAWs to vanish.

  4. Spectroscopy underlying microwave remote sensing of atmospheric water vapor

    Science.gov (United States)

    Tretyakov, M. Yu.

    2016-10-01

    The paper presents a spectroscopist's view on the problem of recovery of the atmosphere humidity profile using modern microwave radiometers. Fundamental equations, including the description of their limitations, related to modeling of atmospheric water vapor absorption are given. A review of all reported to date experimental studies aimed at obtaining corresponding numerical parameters is presented. Best estimates of these parameters related to the Voigt (Lorentz, Gross, Van Vleck - Weisskopf and other equivalent) profile based modeling of the 22- and 183-GHz water vapor diagnostic lines and to non-resonance absorption as well as corresponding uncertainties are made on the basis of their comparative analysis.

  5. Pull-in control due to Casimir forces using external magnetic fields

    CERN Document Server

    Esquivel-Sirvent, R; Cocoletzi, G H

    2009-01-01

    We present a theoretical calculation of the pull-in control in capacitive micro switches actuated by Casimir forces, using external magnetic fields. The external magnetic fields induces an optical anisotropy due to the excitation of magneto plasmons, that reduces the Casimir force. The calculations are performed in the Voigt configuration, and the results show that as the magnetic field increases the system becomes more stable. The detachment length for a cantilever is also calculated for a cantilever, showing that it increases with increasing magnetic field. At the pull-in separation, the stiffness of the system decreases with increasing magnetic field.

  6. The role of magnetoplasmons in Casimir force calculations

    CERN Document Server

    Esquivel-Sirvent, R; Palomino-Ovando, M A; Cocoletzi, G H

    2009-01-01

    In this paper we review the role of magneto plasmon polaritons in the Casimir force calculations. By applying an external constant magnetic field a strong optical anisotropy is induced on two parallel slabs reducing the reflectivity and thus the Casimir force. As the external magnetic field increases, the Casimir force decreases. Thus, with an an external magnetic field the Casimir force can be controlled.The calculations are done in the Voigt configuration where the magnetic field is parallel to the slabs. In this configuration the reflection coefficients for TE and TM modes do not show mode conversion.

  7. Measurement of the electron and ion temperatures by the x-ray imaging crystal spectrometer on joint Texas experimental tokamak

    Science.gov (United States)

    Yan, W.; Chen, Z. Y.; Jin, W.; Lee, S. G.; Shi, Y. J.; Huang, D. W.; Tong, R. H.; Wang, S. Y.; Wei, Y. N.; Ma, T. K.; Zhuang, G.

    2016-11-01

    An x-ray imaging crystal spectrometer has been developed on joint Texas experimental tokamak for the measurement of electron and ion temperatures from the Kα spectra of helium-like argon and its satellite lines. A two-dimensional multi-wire proportional counter has been applied to detect the spectra. The electron and ion temperatures have been obtained from the Voigt fitting with the spectra of helium-like argon ions. The profiles of electron and ion temperatures show the dependence on electron density in ohmic plasmas.

  8. 精品赏析

    Institute of Scientific and Technical Information of China (English)

    欧南

    2014-01-01

    <正>瓦格纳《众神的黄昏》Richard Wagner-Gotterdammerung演唱:德波拉·弗艾特(Deborah Voigt)杰·亨特·莫里斯(Jay Hunter Morris)艾恩·帕特森(Lain Paterson)汉斯-彼得·金(Hans-peter Konig)温蒂·布莱恩·哈默(Wendy Bryn Harmer)伴奏:大都会歌剧院管弦乐团(The Metropolitan Opera Orchestra)指挥:法比奥·路易西(Fabio Luisi)编号:0440 073 4842(2DVD)

  9. SMEs, Competition and Entry - A developing country perspective

    DEFF Research Database (Denmark)

    Jensen, Camilla

    . The main research question is why it is so difficult for new entrepreneurs to enter markets, or in other words, why are the barriers to entry seemingly higher in developing countries? Development writers such as Hernando de Soto and Daron Acemoglu suggest that this question is closely related...... such as competition policy. The model is tested using the World Bank's BEEPS dataset which is a repeated cross section survey of firms across countries in development and transition. This data gives access to observe among other firm size and whether firms pay a bribe or not. This data is combined with Stephan Voigt...

  10. Elastic anisotropy in multifilament Nb$_3$Sn superconducting wires

    CERN Document Server

    Scheuerlein, C; Alknes, P; Arnau, G; Bjoerstad, R; Bordini, B

    2015-01-01

    The elastic anisotropy caused by the texture in the Nb3Sn filaments of PIT and RRP wires has been calculated by averaging the estimates of Voigt and Reuss, using published Nb3Sn single crystal elastic constants and the Nb3Sn grain orientation distribution determined in both wire types by Electron Backscatter Diffraction. At ambient temperature the calculated Nb3Sn E-moduli in axial direction in the PIT and the RRP wire are 130 GPa and 140 GPa, respectively. The calculated E-moduli are compared with tensile test results obtained for the corresponding wires and extracted filament bundles.

  11. La teoría de la relatividad: ayer y hoy

    OpenAIRE

    Cervantes-Cota, Jorge L.; M. A. Rodríguez-Meza

    2006-01-01

    Explicamos los dos postulados dela teoría de la relatividad especial, poniendo énfasis en los conocimientos científicos históricos detrás de las ideas que empleó el joven Albert Einstein en 1905. El papel de científicos como Maxwell, Michelson, Voigt, Lorentz, Fitzgerald, entre otros, es dilucidado. También explicamos la geometría del nuevo espacio-tiempo que emana de la teoría, así como las consecuencias en la medición del espacio, tiempo y masas de observadores en movimiento relativo. Fina...

  12. The Role of a Novel Topological Form of the Prion Protein in Prion Disease

    Science.gov (United States)

    2008-07-01

    are characterizing the phenotype of these mice to further our understanding of CtmPrP– meditated neurotoxicity, which we believe will shed new light...Biol 160:529 –539. Hegde RS, Voigt S, Lingappa VR (1998a) Regulation of protein topology by trans-acting factors at the endoplasmic reticulum. Mol...Cell 2:85–91. Hegde RS, Mastrianni JA, Scott MR, Defea KA, Tremblay P, Torchia M, DeArmond SJ, Prusiner SB, Lingappa VR (1998b) A transmembrane form of

  13. Chronic lymphocytic leukemia: case-based session.

    Science.gov (United States)

    Rai, K R; Döhner, H; Keating, M J; Montserrat, E

    2001-01-01

    Drs. Hartmut Döhner, Michael J. Keating, Kanti R. Rai and Emili Montserrat form the panel to review chronic lymphocytic leukemia (CLL) while focusing on the clinical features of a particular patient. The pace of progress in CLL has accelerated in the past decade. The pathophysiological nature of this disease, as had been known in the past, was based largely on the intuitive and empiric notions of two leaders in hematology, William Dameshek and David Galton. Now the works of a new generation of leaders are providing us with the scientific explanations of why CLL is a heterogeneous disease, perhaps consisting of at least two separate entities. In one form of CLL, the leukemic lymphocytes have a surface immunoglobulin (Ig) variable region gene that has undergone somatic mutations, with tell-tale markers suggesting that these cells had previously traversed the germinal centers. Such patients have a distinctly superior prognosis than their counterparts whose leukemic lymphocytes IgV genes have no mutations (these are indeed immunologically naive cells), who have a worse prognosis. The introduction of fluorescence in situ hybridization (FISH) technique has provided us with new insights into the diverse chromosomal abnormalities that can occur in CLL, and which have significant impact on the clinical behavior and prognosis of patients with this disease. Major advances in therapeutics of CLL also have occurred during the past decade. Two monoclonal antibodies, Campath-1H (anti-CD52) and rituximab (anti-CD20), and one nucleoside analogue, fludarabine, have emerged as three agents of most promise in the front-line treatment of this disease. Studies currently in progress reflect our attempts to find the most effective manner of combining these agents to improve the overall survival statistics for CLL patients. As in many other hematological malignancies, high dose chemotherapy followed by autologous or HLA-compatible allogeneic stem cells rescue strategies are under study as

  14. Intention to use hearing aids: a survey based on the theory of planned behavior

    Directory of Open Access Journals (Sweden)

    Meister H

    2014-09-01

    Full Text Available Hartmut Meister,1 Linda Grugel,1 Markus Meis2 1Jean Uhrmacher Institute for Clinical ENT Research, University of Cologne, Cologne, Germany; 2Hoerzentrum Oldenburg, Oldenburg, Germany Objective: To determine the intention to use hearing aids (HAs by applying the theory of planned behavior (TPB. Design: The TPB is a widely used decision-making model based on three constructs hypothesized to influence the intention to perform a specific behavior; namely, “attitude toward the behavior”, “subjective norm”, and “behavioral control”. The survey was based on a TPB-specific questionnaire addressing factors relevant to HA provision. Study sample: Data from 204 individuals reporting hearing problems were analyzed. Different subgroups were established according to the stage of their hearing help-seeking. Results: The TPB models’ outcome depended on the subgroup. The intention of those participants who had recognized their hearing problems but had not yet consulted an ear, nose, and throat specialist was largely dominated by the “subjective norm” construct, whereas those who had already consulted an ear, nose, and throat specialist or had already tried out HAs were significantly influenced by all constructs. The intention of participants who already owned HAs was clearly less affected by the “subjective norm” construct but was largely dominated by their “attitude toward HAs”. Conclusion: The intention to use HAs can be modeled on the basis of the constructs “attitude toward the behavior”, “subjective norm”, and “behavioral control”. Individual contribution of the constructs to the model depends on the patient’s stage of hearing help-seeking. The results speak well for counseling strategies that explicitly consider the individual trajectory of hearing help-seeking. Keywords: hearing aid uptake, motivation, attitude, subjective norm, behavioral control

  15. G蛋白偶联受体的高分辨结构

    Institute of Scientific and Technical Information of China (English)

    王瑞(译)

    2006-01-01

    哈特姆特·米歇尔(Hartmut Michel)教授,1987年就职于德国法兰克福大学马克斯—普兰克(Max-Planck)生物物理学院,并成为其分子膜生物系的系主任。在这期间,他与来自罗伯特·胡伯(Robert Huber)实验室的乔安·戴森霍费尔(Johann Deisenhofer)合作,成功地获得了世界上第一个膜蛋白晶体一紫色光合细菌的光合作用反应中心的晶体,并以3埃的高精确度确定了该反应中心的三维结构,为此他获得了美国物理学会生物物理奖(与戴森霍费尔分享)和欧洲光生物学会奖章,并与罗伯特·胡伯和乔安·戴森霍费尔共同获得了1988年的诺贝尔化学奖。米歇尔在很多研究协会中担任要职,包括生物化学与分子生物学协会,德国化学家协会,物理生物学协会,德国结晶学协会等,同时,他也是中国科学院的外籍院士。

  16. Energy efficiency and existing buildings. Energetical sanitation of residential buildings and commercial buildings; Energieeffizienz + Bestand. Energetische Sanierung von Wohn- und Nutzgebaeuden

    Energy Technology Data Exchange (ETDEWEB)

    Sick, F. (ed.) [Fachhochschule fuer Technik und Wirtschaft, Berlin (Germany)

    2007-07-01

    Within the first International User Forum - energy efficiency and existing buildings - of the Ostbayerische Technologie Transfer Institut e.V. (Regensburg, Federal Republic of Germany) at 15th and 16th February, 2007, in Bad Staffelstein (Federal Republic of Germany) the following lectures were held: (1) Potentials and markets of the energetic building refurbishment (Andreas Wagner); (2) Implementation of the EU building regulation in the Federal Republic of Germany in DIN V 18599; energy pass, EnEV 2006, results of the legislation (Fred Weigl); (3) Financing and economic efficiency of measures of energetic building refurbishment (Frank Pinsler); (4) Saving energy in building pools - Experiences from 1,000 buildings of the capital Munich (Matthias Domke); (5) Solar housing estates - Energy efficiency and utilization of renewable energy in North-Rhine Westphalia (Hartmut Murschall); (6) Integrated planning - from single components to total project (Boris Mahler); (7) Dynamic simulation - Introduction into methods of calculation for non-residential buildings (Andreas Gerber); (8) Approaches of calculation according to DIN 18599 and evaluation (Helmut E. Feustel); (9) An overview on software tools for an energetic building refurbishment (Anja Rosenbach); (10) Incorporation of regenerative energies in building refurbishment - The 'Solar energy centre' in multi-storey residential buildings (Bernhard Jurisch); (11) Home-automation - networking of plants saves energy and operating costs (Manfred Riedel); (12) Cogeneration-cold coupling (Wolfgang Schoelkopf); (13) International significance of the energetic building refurbishment (Robert Hastings); (14) Energetic reconstruction of plate buildings in Germany, Eastern Austria, Russia and People's Republic of China (Alfred Kerschberger); (15) eea - European Energy Award - The European standard for energy efficient communities (Armand Duetz, Ilga Schwidder); (16) Best practice examples from Austria (Ernst

  17. RTOPO-1: A consistent dataset for Antarctic ice shelf topography and global ocean bathymetry

    Science.gov (United States)

    Timmermann, Ralph

    2010-05-01

    Sub-ice shelf circulation and freezing/melting rates depend critically on an accurate and consistent representation of cavity geometry (i.e. ice-shelf draft and ocean bathymetry). Existing global or pan-Antarctic data sets have turned out to contain various inconsistencies and inaccuracies. The goal of this work is to compile independent regional fields into a global data set. We use the S-2004 global 1-minute bathymetry as the backbone and add an improved version of the BEDMAP topography for an area that roughly coincides with the Antarctic continental shelf. Locations of the merging line have been carefully adjusted in order to get the best out of each data set. High-resolution gridded data for the Amery, Fimbul, Filchner-Ronne, Larsen C and George VI Ice Shelves and for Pine Island Glacier have been carefully merged into the ambient ice and ocean topographies. Multibeam ship survey data for bathymetry in the former Larsen B cavity and the southeastern Bellingshausen Sea have been obtained from the data centers of Alfred Wegener Institute (AWI), British Antarctic Survey (BAS) and Lamont-Doherty Earth Observatory (LDEO), gridded, and again carefully merged into the existing bathymetry map. The resulting global 1-minute data set contains consistent masks for open ocean, grounded ice, floating ice, and bare land surface. The Ice Shelf Cavern Geometry Team: Anne Le Brocq, Tara Deen, Eugene Domack, Pierre Dutrieux, Ben Galton-Fenzi, Dorothea Graffe, Hartmut Hellmer, Angelika Humbert, Daniela Jansen, Adrian Jenkins, Astrid Lambrecht, Keith Makinson, Fred Niederjasper, Frank Nitsche, Ole Anders Nøst, Lars Henrik Smedsrud, and Walter Smith

  18. Repulsive and Restoring Casimir Forces Based on Magneto-Optical Effect

    Institute of Scientific and Technical Information of China (English)

    ZENG Ran; YANG Ya-Ping

    2011-01-01

    The Casimir force direction tuned by the external magnetic field due to the magneto-optical Voigt effect is investigated. The magneto-optical effect gives rise to the modified frequency-dependent electric permittivity and thus the electromagnetic properties of the materials can be adjusted to satisfy the condition of the formation of repulsive Casimir force. It is found that between the ordinary dielectric slab and magneto-optical material slab, a repulsive force may exist by adjusting the applied magnetic field. The restoring Casimir force can also be obtained if suitable parameter values are taken. For realistic materials, the repulsive and the restoring force is shown to possibly take place at typical distances in microelectromechanical systems.%@@ The Casimir force direction tuned by the external magnetic field due to the magneto-optical Voigt effect is investigated.The magneto-optical effect gives rise to the modified frequency-dependent electric permittivity and thus the electromagnetic properties of the materials can be adjusted to satisfy the condition of the formation of repulsive Casimir force.It is found that between the ordinary dielectric slab and magneto-optical material slab,a repulsive force may exist by adjusting the applied magnetic field.The restoring Casimir force can also be obtained if suitable parameter values are taken.For realistic materials,the repulsive and the restoring force is shown to possibly take place at typical distances in microelectromechanical systems.

  19. - and H_2-BROADENED Line Parameters of Carbon Monoxide in the First Overtone Band

    Science.gov (United States)

    Predoi-Cross, Adriana; Esteki, Koorosh; Naseri, Hossein; Devi, V. Malathy; Smith, Mary Ann H.; Mantz, Arlan; Ivanov, Sergei V.

    2016-06-01

    In this study we have re-analyzed high-resolution spectra of pure CO and CO broadened by hydrogen recorded in the spectral range of the first overtone band. We have used four different line shapes in the multispectrum analysis (Voigt, speed dependent Voigt, Rautian, and Rautian with speed dependence) and compared the resulting line shape parameters. The line mixing coefficients have been calculated using the Exponential Power Gap and the Energy Corrected Sudden scaling laws. A classical approach was applied to calculate CO line widths in CO-H_2 and CO-CO collisions. The formulas of classical impact theory are used for calculation of dipole absorption half-widths along with exact 3D Hamilton equations for simulation of molecular motion. The calculations utilize Monte Carlo averaging over collision parameters and simple interaction potential (Tipping-Herman + electrostatic). Molecules are treated as rigid rotors. The dependences of CO half-widths on rotational quantum number J≤ 24 are computed and compared with measured data at room temperature. V. Malathy Devi et al., J. Mol. Spectrosc. 228 (2004) 580-592. R. G. Gordon, J. Chem. Phys. 44 (1966) 3083-3089; ibid., 45 (1966) 1649-1655. J.-P. Bouanich and A. Predoi-Cross, J. Molec. Structure 742 (2005) 183-190 A. Predoi-Cross, J.-P. Bouanich, D. Chris Benner, A. D. May, and J. R. Drummond, J. Chem. Phys. 113 (2000) 158-168

  20. Rheology of fractal networks

    CERN Document Server

    Patricio, Pedro; Duarte, Jorge; Januario, Cristina

    2015-01-01

    We investigate the rheology of a fractal network, in the framework of the linear theory of viscoelasticity. We identify each segment of the network with a simple Kelvin-Voigt element, with a well defined equilibrium length. The final structure retains the elastic characteristics of a solid or a gel. By considering a very simple regular self-similar structure of segments in series and in parallel, in 1, 2 or 3 dimensions, we are able to express the viscoelasticity of the network as an effective generalised Kelvin-Voigt model with a power law spectrum of retardation times, $\\phi\\sim\\tau^{\\alpha-1}$. We relate the parameter $\\alpha$ with the fractal dimension of the gel. In some regimes ($0<\\alpha<1$), we recover the weak power law behaviours of the elastic and viscous moduli with the angular frequencies, $G'\\sim G''\\sim w^\\alpha$, that occur in a variety of soft materials, including living cells. In other regimes, we find different and interesting power laws for $G'$ and $G''$.

  1. Structural analysis of a carbonated hydroxyapatite by the Rietveld method using different profile functions; Analise estrutural de uma hidroxiapatita carbonatada pelo metodo de Rietveld aplicando funcoes de perfil diferentes

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Jorge C. de [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Dept. de Matematica], e-mail: jcaraujo@iprj.uerj.br; Moreira, Elizabeth L.; Moraes, Valeria Conde Alves [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)], e-mail: beth@cbpf.br, e-mail: conde@cbpf.br; Moreira, Ana Paula D. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica], e-mail: duarteap@gmail.com

    2008-10-15

    The crystal structure of the synthetic hydroxyapatite with 12.8 ({+-} 0,64) wt. % CO{sub 3}{sup 2-} ion content was analyzed by X-ray diffraction using the Rietveld refinement method employing Pearson VII and pseudo-Voigt functions to fit the X-ray profile. The results obtained for unit cell parameters when compared to pattern hydroxyapatite showed a decrease in the a (=b) parameter and an increase in the c parameter without significant difference between the functions employed. The separation of the anisotropic broadening of reflections originated from unit cell strains indicated that this effect is dominant in reflection line broadening, principally to hkl plans with an interatomic distance lower than 2,24 angstrom. Modifications in the atomic coordinates of C atom were noted mainly in PO{sub 4}{sup 3-} (B site) and OH{sup -} (A site) sites. The average crystallite size in the crystallography axis directions (002 and 300) suggests equi axial morphology. The results obtained to CO{sub 3}{sup 2}- content were 11.72 ({+-} 0,64) wt. % to Pearson VII and 13.20 ({+-} 0,64) wt. % to pseudo-Voigt function. The refinement of the occupancy factors to C atoms in both sites PO{sub 4}{sup 3-}(B) and OH{sup -} (A) indicated higher insertion in phosphate site than hydroxide site. However, the relative occupancy of the C atom observed in the B site is lower than in the A site. (author)

  2. Study of microstructure in vanadium–palladium alloys by X-ray diffraction technique

    Indian Academy of Sciences (India)

    J Ghosh; S K Chattopadhyay; A K Meikap; S K Chatterjee; P Chatterjee

    2007-10-01

    Present study considers microstructural characterization of vanadium-based palladium (V–Pd) alloys, which are widely used in marine environment due to their high corrosion resistance. The X-ray diffraction line profile analysis (XRDLPA) have been used to assess the microstructure in body centred cubic (bcc) V–Pd alloys having four different nominal compositions in wt.%. X-ray diffraction line broadening analysis on V–Pd alloys has been performed by using different methods like the Warren–Averbach, double-Voigt and Rietveld methods. Finally microstructural defect parameters such as domain size (), r.m.s. microstrain 〈 2 〉1/2, twin fault ('), spacing fault () and deformation stacking fault () were evaluated in these alloys by Fourier line shape analysis using Rietveld method in which the X-ray diffraction profiles of these alloys were described by the pseudo-Voigt function to fit the experimental data. From analysis it has been observed that twin fault, ', and the spacing fault, , are totally absent in these bcc alloy systems because the twin fault, ', has been observed to be either negative or very small (within experimental error limit) for these alloy systems and the spacing fault, , appears to be negative. This analysis also revealed that the deformation stacking fault, , is significantly present in this alloy system and increases with Pd content.

  3. Theoretical and revisited experimentally retrieved He-broadened line parameters of carbon monoxide in the fundamental band

    Science.gov (United States)

    Predoi-Cross, A.; Esteki, K.; Rozario, H.; Naseri, H.; Latif, S.; Thibault, F.; Malathy Devi, V.; Smith, M. A. H.; Mantz, A. W.

    2016-11-01

    We report revisited experimentally retrieved and theoretically calculated He-broadened Lorentz half-width coefficients and He- pressure-shift coefficients of 45 carbon monoxide transitions in the 1←0 band. The spectra analyzed in this study were recorded over a range of temperatures between 79 and 296 K. The He-broadened line parameters and their temperature dependences were retrieved using a multispectrum nonlinear least squares analysis program. The line shape models used in this study include Voigt, speed dependent Voigt, Rautian (to take into account confinement narrowing) and Rautian with speed dependence, all with an asymmetric component added to account for weak line mixing effects. We were unable to retrieve the temperature dependence of line mixing coefficients. A classical method was used to determine the He-narrowing parameters while quantum dynamical calculations were performed to determine He-broadening and He-pressure shifts coefficients at different temperatures. The line mixing coefficients were also derived from the exponential power gap law and the energy corrected sudden approximation. The current measurements and theoretical results are compared with other published results, where appropriate.

  4. Rayleigh-Lamb wave propagation on a fractional order viscoelastic plate.

    Science.gov (United States)

    Meral, F Can; Royston, Thomas J; Magin, Richard L

    2011-02-01

    A previous study of the authors published in this journal focused on mechanical wave motion in a viscoelastic material representative of biological tissue [Meral et al., J. Acoust. Soc. Am. 126, 3278-3285 (2009)]. Compression, shear and surface wave motion in and on a viscoelastic halfspace excited by surface and sub-surface sources were considered. It was shown that a fractional order Voigt model, where the rate-dependent damping component that is dependent on the first derivative of time is replaced with a component that is dependent on a fractional derivative of time, resulted in closer agreement with experiment as compared with conventional (integer order) models, such as those of Voigt and Zener. In the present study, this analysis is extended to another configuration and wave type: out-of-plane response of a viscoelastic plate to harmonic anti-symmetric Lamb wave excitation. Theoretical solutions are compared with experimental measurements for a polymeric tissue mimicking phantom material. As in the previous configurations the fractional order modeling assumption improves the match between theory and experiment over a wider frequency range. Experimental complexities in the present study and the reliability of the different approaches for quantifying the shear viscoelastic properties of the material are discussed.

  5. The UVES Large Program for Testing Fundamental Physics II: Constraints on a Change in {\\mu} Towards Quasar HE 0027-1836

    CERN Document Server

    Rahmani, H; Srianand, R; Noterdaeme, P; Petitjean, P; Molaro, P; Whitmore, J B; Murphy, M T; Centurion, M; Fathivavsari, H; D'Odorico, S; Evans, T M; Levshakov, S A; Lopez, S; Martins, C J A P; Reimers, D; Vladilo, G

    2013-01-01

    We present an accurate analysis of the H2 absorption lines from the zabs ~ 2.4018 damped Ly{\\alpha} system towards HE 0027-1836 observed with the Very Large Telescope Ultraviolet and Visual Echelle Spectrograph (VLT/UVES) as a part of the European Southern Observatory Large Programme "The UVES large programme for testing fundamental physics" to constrain the variation of proton-to-electron mass ratio, {\\mu} = mp/me. We perform cross-correlation analysis between 19 individual exposures taken over three years and the combined spectrum to check the wavelength calibration stability. We notice the presence of a possible wavelength dependent velocity drift especially in the data taken in 2012. We use available asteroids spectra taken with UVES close to our observations to confirm and quantify this effect. We consider single and two component Voigt profiles to model the observed H2 absorption profiles. We use both linear regression analysis and Voigt profile fitting where {\\Delta}{\\mu}/{\\mu} is explicitly considered...

  6. Reproducibility of XPS analysis for film thickness of SiO{sub 2}/Si by active Shirley method

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Ryo, E-mail: MATSUMOTO.Ryo@nims.go.jp [National Institute of Technology, Yonago College, Tottori 683-8502 (Japan); Graduate School of Pure and Applied Science, University of Tsukuba, Tsukuba 305-8577 (Japan); National Institute for Materials Science, Tsukuba 305-0044 (Japan); Nishizawa, Yugo; Kataoka, Noriyuki; Tanaka, Hiromi [National Institute of Technology, Yonago College, Tottori 683-8502 (Japan); Yoshikawa, Hideki; Tanuma, Shigeo [National Institute for Materials Science, Tsukuba 305-0044 (Japan); Yoshihara, Kazuhiro [Scienta Omicron, Inc, Tokyo 140-0013 (Japan)

    2016-02-15

    Highlights: • We proposed a new advantage for estimation of XPS background in active Shirley method. • Active Shirley method can estimate a reproducible background without operator dependence. • Active Shirley method demonstrated that the thickness of the SiO{sub 2} film was estimated at 9.71 ± 0.14 nm from noisy Si 2p peaks in the commonly-used range. • We developed practical software including useful GUI with active Shirley method. - Abstract: The active Shirley method has been recently proposed for reproducibly estimating the background and peaks of X-ray photoelectron spectroscopy (XPS) spectra because of its automatic tuning of starting and ending points of the Shirley-type background spectra. This reproducibility is significantly affected not only by a software algorithm of the active Shirley method but also by a choice of the initial ending points or a shape of Voigt function. In this work, we provided an example of the reproducibility of XPS analysis for SiO{sub 2} film (9.2 nm thick) on Si wafer by changing the range of initial ending points or a shape of Voigt function in the active Shirley method. It demonstrated that the thickness of the SiO{sub 2} film was estimated at 9.71 ± 0.14 nm from noisy Si 2p peaks in the commonly-used range.

  7. Uranium M x-ray emission spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Keski-Rahkonen, O.; Krause, M.O.

    1977-03-01

    The uranium M x-ray spectrum from a thick metallic target excited by 12-keV electrons was measured by the PAX (photoelectron spectrometry for the analysis of x rays) technique. Energies of the strongest lines were obtained with an accuracy of 0.1 eV using Ag L..beta../sub 1/ and Ag L..cap alpha../sub 1/ as standards. Widths of the uranium lines were obtained by deconvoluting the measured Voigt profiles, and the experimental values were found to agree satisfactorily with McGuire's Hartree-Slater predictions. Natural widths of 4.0(3) and 3.8(3) eV were derived for the M/sub 4/ and M/sub 5/ levels, respectively, and the energies of the M/sub 4/, M/sub 5/, N/sub 2/, and N/sub 3/ levels in uranium metal were determined. Relative intensities of the M lines were measured, and branching ratios were found to be in fair agreement with relativistic Hartree-Slater predictions. The satellite structures of the M..cap alpha../sub 1/ and M..beta.. lines were interpreted in terms of the pertinent multiple-hole configurations. Finally, an approximate analytic expression for the Voigt half-width and its graphical representation are given.

  8. The VLab repository of thermodynamics and thermoelastic properties of minerals

    Science.gov (United States)

    Da Silveira, P. R.; Sarkar, K.; Wentzcovitch, R. M.; Shukla, G.; Lindemann, W.; Wu, Z.

    2015-12-01

    Thermodynamics and thermoelastic properties of minerals at planetary interior conditions are essential as input for geodynamics simulations and for interpretation of seismic tomography models. Precise experimental determination of these properties at such extreme conditions is very challenging. Therefore, ab initio calculations play an essential role in this context, but at the cost of great computational effort and memory use. Setting up a widely accessible and versatile mineral physics database can relax unnecessary repetition of such computationally intensive calculations. Access to such data facilitates transactional interaction across fields and can advance more quickly insights about deep Earth processes. Hosted by the Minnesota Supercomputing Institute, the Virtual Laboratory for Earth and Planetary Materials (VLab) was designed to develop and promote the theory of planetary materials using distributed, high-throughput quantum calculations. VLab hosts an interactive database of thermodynamics and thermoelastic properties or minerals computed by ab initio. Such properties can be obtained according to user's preference. The database is accompanied by interactive visualization tools, allowing users to repeat and build upon previously published results. Using VLab2015, we have evaluated thermoelastic properties, such as elastic coefficients (Cij), Voigt, Reuss, and Voigt-Reuss-Hill aggregate averages for bulk (K) and shear modulus (G), shear wave velocity (VS), longitudinal wave velocity (Vp), and bulk sound velocity (V0) for several important minerals. Developed web services are general and can be used for crystals of any symmetry. Results can be tabulated, plotted, or downloaded from the VLab website according to user's preference.

  9. Controlling Liquid Release by Compressing Electrospun Nanowebs

    Directory of Open Access Journals (Sweden)

    K.G. Kornev

    2009-09-01

    Full Text Available Electrospun nanowebs with pores ranging from nanometers to micrometers, constitute new materials with enhanced absorbency and ability to retain liquids in pores for a long period of time. These materials can be used as nanofluidic probes collecting minute amount of liquids. However, extraction of liquids from nanofibrous materials presents a problem: menisci in the interfiber pores create very high suction pressure which holds the liquid inside the material. This problem can be resolved if the probe is completely filled with the liquid: menisci at the probe edges become flat to establish a pressure equilibrium with the atmosphere. Therefore, one can take advantage of the nanoweb softness and extract liquid by mechanically deforming the nanowebs. We show that the liquid-saturated nanowebs follow the Voigt-type rheology upon loading. We theoretically explain this behavior and derive the relations between the Voigt phenomenological parameters, nanoweb permeability and compression modulus. We show that the limiting deformations follow the Hooke’s law which assumes linear relation between the extracted volume of liquid and the applied load. Because of this predictable behavior, the nanoweb probes can be engineered to release minute liquid doses upon compression. The developed experimental methodology can be used for characterization of nanostructured materials which otherwise impossible to analyze by using the existing instruments.

  10. Pressure-broadening of water transitions near 7180 cm(-1) by helium isotopes.

    Science.gov (United States)

    Campbell, H M; Havey, D K

    2013-05-15

    In this study, pressure-broadening parameters for several H2O transitions near 7180 cm(-1) are obtained which describe collisions with (3)He and (4)He. The sensitivity of those parameters to choice of theoretical line profile (Galatry vs. Voigt) is investigated. H2O is an important species in atmospheric chemistry and astronomy. Because of this, basic fundamental research, which explores the nature of the H2O spectrum in the presence of different gases of varying physical properties, can provide useful reference data which can be applied in the fields of atmospheric and planetary remote sensing. Measurements were made using an intensity-modulated laser photoacoustic spectrometer. Results from the present work show that Galatry line profiles, with a constrained narrowing parameter, more accurately describe experimental spectra than Voigt profiles over a wide range of experimental pressure conditions. Average pressure-broadening parameters were found to be 0.0216 cm(-1)/atm and 0.0209 cm(-1)/atm for H2O in (3)He and (4)He, respectively, and were compared to a literature model for the mass-dependence of line broadening. Specific values were obtained for each transition with nominal combined uncertainties of 2-6%.

  11. Linear and nonlinear viscoelastic arterial wall models: application on animals

    CERN Document Server

    Ghigo, Arthur; Armentano, Ricardo; Lagrée, Pierre-Yves; Fullana, Jose-Maria

    2016-01-01

    This work deals with the viscoelasticity of the arterial wall and its influence on the pulse waves. We describe the viscoelasticity by a non-linear Kelvin-Voigt model in which the coefficients are fitted using experimental time series of pressure and radius measured on a sheep's arterial network. We obtained a good agreement between the results of the nonlinear Kelvin-Voigt model and the experimental measurements. We found that the viscoelastic relaxation time-defined by the ratio between the viscoelastic coefficient and the Young's modulus-is nearly constant throughout the network. Therefore, as it is well known that smaller arteries are stiffer, the viscoelastic coefficient rises when approaching the peripheral sites to compensate the rise of the Young's modulus, resulting in a higher damping effect. We incorporated the fitted viscoelastic coefficients in a nonlinear 1D fluid model to compute the pulse waves in the network. The damping effect of viscoelasticity on the high frequency waves is clear especiall...

  12. Recent Line-Shape and Doppler Thermometry Studies Involving Transitions in the ν1 +ν3 Band of Acetylene

    Science.gov (United States)

    Hashemi, Robab; Rozario, Hoimonti; Povey, Chad; Garber, Jolene; Derksen, Mark; Predoi-Cross, Adriana

    2014-06-01

    The line positions for transitions in the ν1 +ν3 band are often used as a frequency standard by the telecom industry and also needed for planetary atmospheric studies. Four relevant studies have been recently carried out in our group and will be discussed briefly below. (1) N2-broadened line widths and N2-pressure induced line shifts have been measured for transitions in the ν1 +ν3 band of acetylene at seven temperatures in the range 213333K to obtain the temperature dependences of broadening and shift coefficients. The Voigt and hard-collision line profile models were used to retrieve the line parameters. This study has been published in Molecular Physics, 110 Issue 21/22 (2012) 2645-2663. (2) Six nitrogen perturbed transitions of acetylene within the ν1 +ν3 absorption band have been recorded using a 3-channel diode laser spectrometer. We have examined C2H2 spectra using a hard collision (Rautian) profile over a range of five temperatures (213 K-333 K). From these fits we have obtained the N2-broadening and narrowing coefficients of C2H2 and examined their temperature dependence. The experimentally measured narrowing coefficients have been used to estimate the nitrogen diffusion coefficients. The broadening coefficients and corresponding temperature dependence exponents have also been compared to that of calculations completed using a classical impact approach on an ab initio potential energy surface. We have observed a good agreement between our theoretical and experimental results. This study was published in Canadian Journal of Physics 91(11) 896-905 (2013). (3) An extension of the previous study was to analyze the room temperature for the same six transitions using the Voigt, Rautian, Galatry, RautianGalatry and Correlated Rautian profiles. For the entire pressure range, we have tested the applicability of these line-shape models. Except for Voigt profile, Dicke narrowing effect has been considered in all mentioned line-shape models. The experimental

  13. Dental operating lights and illumination of the dental surgery.

    Science.gov (United States)

    Viohl, J

    1979-06-01

    The requirements laid down in national and international standards and draft standards provide helpful guidelines for optimum illumination (Fig. 1, Table I). General room illumination with 500 lx and illumination of the working area with 1000 lx are best achieved with a larger number of fluorescent lamps on the ceiling above and in front of the dental chair. Daylight white lamps with good colour rendering (e.g. Osram colour 19 or Philips colour 47) are a good combination with changing daylight and the colour of light of the operating light. The colour of external skin, mucous membrane and teeth appears natural. The eight surgical lights examined differ in quality (Figs. 2-9). The maximum illuminance is between 9000 and 21 000 lx and is thus sufficiently high. The evenness of light distribution within an ellipse 9 cm and 18 cm in diameter is between 1 : 4 and 1 : 15 (Figs. 10 and 11). Illuminance can be adjusted to the work in hand by means of controls. If the patient looks into the operating lights (Figs. 2c and 9c), maximum luminances of 5 cd/cm2-20 cd/cm2 occur 8 cm above the illuminance maximum in six operating lights. Luminances of more than 20 cd/cm2 cause squinting and running eyes. A light fitting with more than 200 cd/cm2 should not be used. A sharp fall in illuminance (distinct light/dark threshold) and low luminances to the patient's eyes can be achieved with very directed light. Very directed light leads to very heavy shadows. Similarly, less specifically directed light leads to softer shadows so that objects in the oral cavity can be discerned easily, but the patient is no longer dazzled. The following operating lights can be recommended if the patient is to suffer as little glare as possible: Den-Tel-Ez Daray, and Belmont Type 040, Faro Sunlight S 70, Ritter Super Starlite; as well as: Chirana Fax, Siemens Sirolux. The following can be recommended for good illumination of the oral cavity: Belmont Type 040, Chirana Fax, Emda Top Spot, Faro Sunlight S 70

  14. Environmental controls for the precipitation of different fibrous calcite cement fabrics

    Science.gov (United States)

    Ritter, Ann-Christine; Wiethoff, Felix; Neuser, Rolf D.; Richter, Detlev K.; Immenhauser, Adrian

    2016-04-01

    Abiogenic calcite cements are widely used as climate archives. They can yield information on environmental change and climate dynamics at the time when the sediment was lithified in a (marine) diagenetic environment. Radiaxial-fibrous (RFC) and fascicular-optic fibrous (FOFC) calcite cements are two very common and similar pore-filling cement fabrics in Palaeozoic and Mesozoic carbonate rocks (Richter et al., 2011) and in Holocene Mg-calcitic speleothems (Richter et al., 2015). Both fabrics are characterised by distinct crystallographic properties. Current research has shown that these fabrics are often underexplored and that a careful combination of conservative and innovative proxies allows for a better applicability of these carbonate archives to paleoenvironmental reconstructions (Ritter et al., 2015). A main uncertainty in this context is that it is still poorly understood which parameters lead to the formation of either RFC or FOFC and if differential crystallographic parameters affect proxy data from these fabrics. This study aims at a better understanding of the environmental factors that may control either RFC or FOFC precipitation. Therefore, suitable samples (a stalagmite and a Triassic marine cement succession), each with clearly differentiable layers of RFC and FOFC, were identified and analysed in high detail using a multi-proxy approach. Detailed thin section and cathodoluminescence analysis of the samples allowed for a precise identification of layers consisting solely of either RFC or FOFC. Isotopic (δ13C, δ18O) as well as trace elemental compositions have been determined and the comparison of data obtained from these different carbonate archives sheds light on changes in environmental parameters during RFC or FOFC precipitation. References: Richter, D.K., et al., 2011. Radiaxial-fibrous calcites: A new look at an old problem. Sedimentary Geology, 239, 26-36 Richter, D.K., et al., 2015. Radiaxial-fibrous and fascicular-optic Mg-calcitic cave

  15. Alkalithermophilic actinomycetes in a subtropical area of Jujuy, Argentina Actinomicetos termoalcalófilos del área subtropical de Jujuy, Argentina

    Directory of Open Access Journals (Sweden)

    L. Carrillo

    2009-06-01

    Full Text Available The objective of this study was to examine the alkalithermophilic actinomycete communities in the subtropical environment of Jujuy, Argentina, characterized by sugarcane crops. Laceyella putida, Laceyella sacchari, Thermoactinomyces intermedius, Thermoactinomyces vulgaris and Thermoflavimicrobium dichotomicum were isolated on the media with novobiocin, from sugar cane plants and renewal rhizospheres, and grass and wood soils. Soil pH was almost neutral or lightly alkaline, except for grass soil acidified by lactic liquor. A smaller number of actinomycetes was found on the living plants and bagasse (recently obtained or stored according to the Ritter method with respect to decomposed leaves on the soil. Thermophilic species of Laceyella, Thermoactinomyces, Thermoflavimicrobium, Saccharomonospora, Streptomyces and Thermononospora were isolated on the media without novobiocin, from composted sugar cane residues. Air captured near composted bagasse piles, contained alkalithermophilic actinomycete spores.El objetivo de este trabajo fue examinar los actinomicetos termoalcalófilos presentes en el área subtropical de Jujuy, Argentina, caracterizada por el cultivo de la caña de azúcar. Se aislaron en medio con novobiocina las especies Laceyella putida, Laceyella sacchari, Thermoactinomyces intermedius, Thermoactinomyces vulgaris y Thermoflavimicrobium dichotomicum a partir de la rizósfera de plantas y de renuevos de caña de azúcar, así como de suelos de pastura y de monte natural. El pH de los suelos era casi neutro a ligeramente alcalino, excepto en un solo caso en que el suelo estaba acidificado por licor láctico. El número de actinomicetos encontrados sobre los tejidos vivos y en el bagazo recién obtenido o almacenado según el método de Ritter fue pequeño en comparación con el observado sobre las hojas en descomposición. L. sacchari predominó respecto de T. vulgaris. Se aislaron especies termoalcalófilas de Laceyella

  16. SeisCube Instrument and Environment Considerations for the Didymos System Geophysical Exploration

    Science.gov (United States)

    Cadu, Alexandre; Murdoch, Naomi; Mimoun, David; Karatekin, Ozgur; Garica, Raphaël F.; Carrasco, Jose A.; De Quiros, Francisco G.; Vasseur, Hugues; Eubanks, Marshall; Radley, Charles; Ritter, Birgit; Dehant, Veronique

    2016-04-01

    In the context of the Asteroid Impact & Deviation Assessment (AIDA) mission proposed by ESA and NASA, the Asteroid Geophysical Explorer (AGEX) mission concept has been selected for a preliminary study phase. Two 3-Unit CubeSats are embedded into the AIM probe and released into the asteroid binary system [1]. SeisCube will be deployed close to the secondary to reach its surface at a low relative velocity in order to stay on the ground after several rebounds, in a similar way that is foreseen for Mascot-2. The purpose of SeisCube is to provide information about the surface, the sub-surface and the internal structure of the asteroid, by analyzing rebound acceleration profile and seismic activity [2]. We describe the considered instrumentation necessary to fulfill the science objectives (gravimeters, accelerometers, geophones, etc.) in terms of measurement dynamics, frequency ranges, acquisition methods and other common budgets for space equipment. We also present the environment considerations which have to be taken into account for the platform and payload designs. The thermal aspect will be particularly discussed since it is a major issue in the airless body exploration [3] [4]. It implies some modifications in the CubeSat structure, integration and thermal regulation to ensure survival and operations under extreme conditions at the asteroid surface. We then describe the platform subsystems needed to ensure the operations after the deployment and the associated budgets and accommodation. As a direct consequence of the previous topics, we will finally discuss the possible trades-off to satisfy the main science requirements and the associated concept of operations. [1] O. Karatekin, D. Mimoun, J. A. Carrasco, N. Murdoch, A. Cadu, R. F. Garcia, F. G. De Quiros, H. Vasseur, B. Ritter, M. Eubanks, C. Radley and V. Dehant, "The Asteroid Geophysical Explorer (AGEX): Proposal to explore Didymos system using Cubsats," in European Geophysical Union, 2016. [2] N. Murdoch, A

  17. Radiative and temperature effects of aerosol simulated by the COSMO-Ru model for different atmospheric conditions and their testing against ground-based measurements and accurate RT simulations

    Science.gov (United States)

    Chubarova, Nataly; Poliukhov, Alexei; Shatunova, Marina; Rivin, Gdali; Becker, Ralf; Muskatel, Harel; Blahak, Ulrich; Kinne, Stefan; Tarasova, Tatiana

    2017-04-01

    We use the operational Russian COSMO-Ru weather forecast model (Ritter and and Geleyn, 1991) with different aerosol input data for the evaluation of radiative and temperature effects of aerosol in different atmospheric conditions. Various aerosol datasets were utilized including Tegen climatology (Tegen et al., 1997), updated Macv2 climatology (Kinne et al., 2013), Tanre climatology (Tanre et al., 1984) as well as the MACC data (Morcrette et al., 2009). For clear sky conditions we compare the radiative effects from the COSMO-Ru model over Moscow (55.7N, 37.5E) and Lindenberg/Falkenberg sites (52.2N, 14.1E) with the results obtained using long-term aerosol measurements. Additional tests of the COSMO RT code were performed against (FC05)-SW model (Tarasova T.A. and Fomin B.A., 2007). The overestimation of about 5-8% of COSMO RT code was obtained. The study of aerosol effect on temperature at 2 meters has revealed the sensitivity of about 0.7-1.1 degree C per 100 W/m2 change in shortwave net radiation due to aerosol variations. We also discuss the radiative impact of urban aerosol properties according to the long-term AERONET measurements in Moscow and Moscow suburb as well as long-term aerosol trends over Moscow from the measurements and Macv2 dataset. References: Kinne, S., O'Donnel D., Stier P., et al., J. Adv. Model. Earth Syst., 5, 704-740, 2013. Morcrette J.-J.,O. Boucher, L. Jones, eet al, J.GEOPHYS. RES.,VOL. 114, D06206, doi:10.1029/2008JD011235, 2009. Ritter, B. and Geleyn, J., Monthly Weather Review, 120, 303-325, 1992. Tanre, D., Geleyn, J., and Slingo, J., A. Deepak Publ., Hampton, Virginia, 133-177, 1984. Tarasova, T., and Fomin, B., Journal of Atmospheric and Oceanic Technology, 24, 1157-1162, 2007. Tegen, I., Hollrig, P., Chin, M., et al., Journal of Geophysical Research- Atmospheres, 102, 23895-23915, 1997.

  18. Morphology and anatomy of Rhipsalis cereuscula, Rhipsalis floccosa subsp. hohenauensis and Lepismium cruciforme (Cactaceae seedlings Morfología y anatomía de las plántulas de Rhipsalis cereuscula, Rhipsalis floccosa subsp. hohenauensis y Lepismium cruciforme (Cactaceae

    Directory of Open Access Journals (Sweden)

    Alan C. Secorun

    2011-03-01

    Full Text Available Rhipsalis cereuscula Haw., Rhipsalis floccosa subsp. hohenauensis (F. Ritter Barthlott et N. P. Taylor and Lepismium cruciforme (Vellozo Miquel are obligatory epiphytes that occur frequently on tree trunks of remnant forests in Maringa, Paraná state, Brazil. Morphological and anatomical analyses regarding the seedlings were carried out. The seedlings were prepared according to techniques of resin inclusions and histochemical tests. Seedlings were phanerocotyledonar and originated from seeds with operculum. The root was diarch and the hypocotyl presented transition root-stem structure. The cotyledons were sessile, reduced, with homogeneous mesophyll. The epicotyl (phylloclade presented a lot of parenchyma and reduced vascular cylinder. The 3 studied species showed anatomical characteristics similar to those described for species of Lepismium and Rhipsalis as well as other cacti.Rhipsalis cereuscula Haw., Rhipsalis floccosa subsp. hohenauensis (F. Ritter Barthlott et N. P. Taylor y Lepismium cruciforme (Vellozo Miquel son epífitos obligatorios que frecuentemente habitan en los troncos del árbol de matorrales secundarios de Maringá, Paraná, Brasil. Se analizaron la morfología y anatomía de las plántulas de estas especies. Las plántulas fueron procesadas según las técnicas de inclusión en resina y pruebas histoquímicas. Las plántulas se clasificaron como fanerocotiledonares y se originaron de semillas con opérculo. La raíz era diarca y el hipocótilo presentó estructura de transición raíz-tallo. Los cotiledones fueron sésiles, reducidos, con el mesófilo homogéneo. El epicótilo (filocladio presentó mucho parénquima y el cilindro vascular reducido. Las 3 especies presentaron características anatómicas similares a las descritas para especies de Lepismium y Rhipsalis, así como otras cactáceas.

  19. Automatic learning rate adjustment for self-supervising autonomous robot control

    Science.gov (United States)

    Arras, Michael K.; Protzel, Peter W.; Palumbo, Daniel L.

    1992-01-01

    Described is an application in which an Artificial Neural Network (ANN) controls the positioning of a robot arm with five degrees of freedom by using visual feedback provided by two cameras. This application and the specific ANN model, local liner maps, are based on the work of Ritter, Martinetz, and Schulten. We extended their approach by generating a filtered, average positioning error from the continuous camera feedback and by coupling the learning rate to this error. When the network learns to position the arm, the positioning error decreases and so does the learning rate until the system stabilizes at a minimum error and learning rate. This abolishes the need for a predetermined cooling schedule. The automatic cooling procedure results in a closed loop control with no distinction between a learning phase and a production phase. If the positioning error suddenly starts to increase due to an internal failure such as a broken joint, or an environmental change such as a camera moving, the learning rate increases accordingly. Thus, learning is automatically activated and the network adapts to the new condition after which the error decreases again and learning is 'shut off'. The automatic cooling is therefore a prerequisite for the autonomy and the fault tolerance of the system.

  20. The Distorted Winds of V444 Cygni: New Insights from Spectropolarimetry

    Science.gov (United States)

    Hoffman, Jennifer L.; Ashley, Sierra F.; Ornelas, Jose L.; Fullard, Andrew; Lomax, Jamie R.; Shrestha, Manisha; Babler, Brian L.; Bjorkman, Jon Eric; Bjorkman, Karen S.; Davidson, James W.; Meade, Marilyn; Nordsieck, Kenneth H.; Richardson, Noel

    2017-01-01

    V444 Cygni is a close, eclipsing WR+O binary system characterized by strong X-ray emission and colliding winds whose shapes are distorted by its rapid orbital velocity and powerful radiative forces. It also exhibits periodic polarimetric variability both in the continuum and in the strong emission lines of He II λ4686, Hα+He I λ6560, and N IV λ7125 these line polarization variations probe the distribution of line formation regions in the complex winds. Sparse spectropolarimetric coverage has limited the reliability of the line polarization analysis in past studies. We here present new line polarization curves that incorporate 11 recent observations of V444 Cyg, obtained with the HPOL spectropolarimeter at the University of Toledo’s Ritter Observatory, into the existing dataset. Because most of these data were taken with the blue grating, we focus primarily on the improved He II λ4686 polarization curve. Although the data display significant stochastic variability by virtue of spanning 27 years, the addition of the new observations allows a more robust analysis than was previously possible. We discuss our interpretation of the updated curves in light of current models for V444 Cyg and other WR+O binary systems. Accurately characterizing the structures of the wind collision regions in such systems is key to understanding the evolution of such massive binary systems and properly accounting for their contribution to the supernova (and possible GRB) progenitor population.

  1. Poetry, Nature and Science: Romantic Nature Philosophy in the Works of Novalis and E. T. a. Hoffmann

    Science.gov (United States)

    Weisend, Ausma Skerbele

    The nature philosophy of the early Romantic period in Germany attempted to find a synthesis of science and philosophy in a new philosophy of nature. This philosophy was first formulated by F. W. J. Schelling and influenced by the galvanic experiments of J. W. Ritter. Novalis is a unique figure in romanticism since he combines scientific expertise with philosophical insight and poetic imagination. In Lehrlinge zu Sais he explores the significance of nature's language and presents different relationships between man and nature. Novalis thinks that a synthesis of all divergent elements in nature and society is necessary to transform the world. In Klingsohrs Marchen this transformation is accomplished by poetic activation of the physical sciences and by the power of love. After 1800 the romantic movement becomes interested in the problems of subconscious and abnormal psychological states, which are seen as contacts with a more spiritual level of existence. These ideas, expressed in a popular form by G. H. Schubert, provide a rich source of materials for E. T. A. Hoffmann, who elevates the realms of poetry and music in his fairy tales, but sees only negative qualities in science. Hoffmann's protagonists find that love, music, and poetry are the greatest forces in life. The figure of the scientist becomes an evil magician with no regard for human values. The romantic movement failed to unite the values of humanities with the insights of physical sciences. The problem of autonomy isolates both modern science and modern literature from the ethical values of society.

  2. [Oswald Schwarz: a pioneer in psychosomatic urology and sexual medicine].

    Science.gov (United States)

    Berberich, H J; Schultheiss, D; Kieser, B

    2015-01-01

    Oswald Schwarz, a urologist from Vienna, was a scholar of Anton Ritter von Frisch and Hans Rubritius. As a physician during World War I, he was confronted with numerous bullet wounds to the spinal cord. In 1919, he completed his professorial thesis"Bladder dysfunction as a result of bullet wounds to the spinal cord". Oswald Schwarz was known as a committed surgeon. As an urologist he also treated patients with sexual dysfunction. Besides his practical and scientific urology-related work, he was also interested in psychology and philosophy. He held lectures on both subjects earning himself the nickname, the Urosoph. In the 1920s, Oswald Schwarz belonged to the inner circle of Alfred Adler, the founder of Individual Psychology, and was editor of the first psychosomatic textbook published in German, "Psychological origin and psychotherapy of physical symptoms" (1925). In addition, Schwarz wrote numerous articles and several books on sexual medicine. He also made many valuable contributions to the development of medical anthropology. Altogether, his work includes over 130 publications. Faced with the rise of fascism and National Socialism in Europe, Oswald Schwarz, who was of Jewish origin, emigrated to England in 1934. There he died in 1949. Unfortunately his scientific work has largely been forgotten. The aim of the following article is to remind us of his important contributions to the field.

  3. Determinação do potencial antioxidante in vitro de frutos do Cerrado brasileiro

    Directory of Open Access Journals (Sweden)

    Mônica Lopes Morais

    2013-06-01

    Full Text Available Extratos em metanol e acetona de diferentes espécies do Cerrado, semente de Solanum lycocarpum A. St.-Hil (Lobeira, polpa de Byrsonima verbascifolia (L. DC. (Murici, epicarpo e mesocarpo de Caryocar brasiliense Cambess (Pequi e pendúculo de Cipocereus minensis F. Ritter (Quiabo-da-lapa foram submetidos a ensaios antioxidantes in vitro para avaliar a capacidade de sequestrar os radicais orgânicos DPPH e ABTS.+, reduzir o ferro (FRAP e/ ou inibir a peroxidação lipídica (β-caroteno. Todas as amostras apresentaram considerável atividade antioxidante, embora em diferentes proporções, destacando-se o mesocarpo de Caryocar brasiliense como o responsável pela maior atividade antioxidante por captura de radicais livres (DPPH e ABTS e poder de redução do metal (FRAP e o pendúnculo de Cipocereus minensis frente à inibição da peroxidação lipídica (B-caroteno. Os frutos estudados podem ser considerados fontes potenciais de antioxidantes naturais e podem ser explorados como aditivos alimentares promissores para a prevenção de doenças, bem como para a manutenção da saúde.

  4. Effects of Religious Priming Concepts on Prosocial Behavior Towards Ingroup and Outgroup.

    Science.gov (United States)

    Batara, Jame Bryan L; Franco, Pamela S; Quiachon, Mequia Angelo M; Sembrero, Dianelle Rose M

    2016-11-01

    Several studies show that there is a connection between religion and prosociality (e.g., Saroglou, 2013). To investigate whether there is a causal relationship between these two variables, a growing number of scholars employed priming religious concepts and measure its influence on prosocial behavior (e.g., Pichon, Boccato, & Saroglou, 2007). In the recent development of religious priming, Ritter and Preston (2013) argued that different primes (agent prime, spiritual/abstract prime, and institutional prime) may also have varying influence on prosocial behavior specifically helping an ingroup or an outgroup target. With this in mind, a 2 (social categorization of the target of help) by 3 (agent prime, institutional prime, spiritual prime) experiment was conducted to directly investigate this hypothesis. Results suggest that priming religious concepts especially the spiritual prime can increase prosocial behaviors. However, no significant effect was found on the social categorization which implies that Filipino participants elicit prosocial behavior regardless of the social categorization (be it ingroup or outgroup) of the target of help. The present study's findings contribute to further the literature on religious priming and its influence on prosocial behavior.

  5. VARIABILITY IN OPTICAL SPECTRA OF {epsilon} ORIONIS

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Gregory B. [Department of Physics, Adrian College, Adrian, MI 49221 (United States); Morrison, Nancy D., E-mail: gthompson@adrian.edu, E-mail: nmorris@utnet.utoledo.edu [Ritter Astrophysical Research Center, Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft, Toledo, OH 43606 (United States)

    2013-04-15

    We present the results of a time series analysis of 130 echelle spectra of {epsilon} Ori (B0 Ia), acquired over seven observing seasons between 1998 and 2006 at Ritter Observatory. The equivalent widths of H{alpha} (net) and He I {lambda}5876 were measured and radial velocities were obtained from the central absorption of He I {lambda}5876. Temporal variance spectra (TVS) revealed significant wind variability in both H{alpha} and He I {lambda}5876. The He I TVS have a double-peaked profile consistent with radial velocity oscillations. A periodicity search was carried out on the equivalent width and radial velocity data, as well as on wavelength-binned spectra. This analysis has revealed several periods in the variability with timescales of two to seven days. Many of these periods exhibit sinusoidal modulation in the associated phase diagrams. Several of these periods were present in both H{alpha} and He I, indicating a possible connection between the wind and the photosphere. Due to the harmonic nature of these periods, stellar pulsations may be the origin of some of the observed variability. Periods on the order of the rotational period were also detected in the He I line in the 1998-1999 season and in both lines during the 2004-2005 season. These periods may indicate rotational modulation due to structure in the wind.

  6. El síndrome de escaldadura estafilocócica. Presentación de caso.

    Directory of Open Access Journals (Sweden)

    Yanisbel Rolo Naranjo

    2009-06-01

    Full Text Available El síndrome de escaldadura estafilocócica o enfermedad de Ritter es una enfermedad rara, aunque es más frecuente en la edad pediátrica que en el adulto. La presentación clínica es característica, se produce un cuadro de descamación intraepidérmica por diseminación hematógena de la toxina desde lesiones cutaneomucosas. Se presenta un caso de una Lactante femenina de 7 meses, que acude al cuerpo de guardia del Hospital Pediátrico Provincial “ José Martí y Pérez” de Sancti Spíritus: un enrojecimiento alrededor de la boca y las orejas que se fue extendiendo progresivamente al cuello con irritabilidad sobre todo al manipular las lesiones, diagnosticándose una urticaria aguda, llevó tratamiento con antihistamínicos e hidrocortisona sin mejoría clínica se le diagnostica finalmente un síndrome de escaldadura estafilocócica, que después de su tratamiento permite su recuperación.

  7. Transport characteristics of nanoparticle-based ferrofluids in a gel model of the brain

    Directory of Open Access Journals (Sweden)

    Soubir Basak

    2009-04-01

    Full Text Available Soubir Basak1, David Brogan2, Hans Dietrich2, Rogers Ritter3, Ralph G Dacey2, Pratim Biswas11Aerosol and Air Quality Research Laboratory, Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA; 2Department of Neurological Surgery, Washington University School of Medicine, St. Louis, MO, USA; 3Stereotaxis Inc., St. Louis, MO, USAAbstract: A current advance in nanotechnology is the selective targeting of therapeutics by external magnetic field-guided delivery. This is an important area of research in medicine. The use of magnetic forces results in the formation of agglomerated structures in the field region. The transport characteristics of these agglomerated structures are explored. A nonintrusive method based on in situ light-scattering techniques is used to characterize the velocity of such particles in a magnetic field gradient. A transport model for the chain-like agglomerates is developed based on these experimental observations. The transport characteristics of magnetic nanoparticle drug carriers are then explored in gel-based simulated models of the brain. Results of such measurements demonstrate decreased diffusion of magnetic nanoparticles when placed in a high magnetic field gradient.  Keywords: nanoparticle ferrofluid, gel-brain model, drug delivery, magnetic agglomeration, transport, magnetic fields

  8. Perils of Neglecting Lattice Relaxation in the Pressure Dependence of Deep Luminescence Bands in Wide Gap Semiconductors

    Science.gov (United States)

    Iota, V.; Weinstein, B. A.

    1998-03-01

    Deep defect states are often assumed to be insensitive to pressure because of their localized atomic-like character. In apparent conflict with this, experiments on widegap II-VI materials find that the pressure shifts of many 'midgap' photoluminescence (PL) bands associated with large-lattice-relaxation defects are more rapid than the shift of the bandgap(B. Weinstein, T. Ritter, et. al., Phys. Stat. Sol. (b) 198), 167 (1996). To study this, we measured the effects of pressure on the PL and PL-excitation (PLE) bands arising from the Zn-vacancy (V_Zn) and the P_Se deep acceptor centers in ZnSe. Using the observed pressure variation of the Stokes shifts and the established 1 atm. configuration coordinate (CC) models( D.Y. Jeon, H.P Gislason, G.D. Watkins, Phys. Rev. B 48), 7872 (1993), we were able to infer quantitative CC-diagrams at any pressure. Our results show that the pressure dependence of the lattice relaxation contributes a substantial fraction (several meV/kbar) to the overall shift of the PL-bands, and, hence, must be included. For the case of the V_Zn, simple calculations of the Jahn-Teller splitting using dangling-bond orbitals support this conclusion. vih/March98/>figures

  9. Hα line profile variability in the B8Ia-type supergiant Rigel (β Ori)

    Science.gov (United States)

    Morrison, N. D.; Rother, R.; Kurschat, N.

    2008-04-01

    Hα observations of Rigel obtained on 184 nights during the past ten years with the 1-m telescope and ´echelle spectrograph of Ritter Observatory are surveyed. The line profiles were classified in terms of morphology. About 1/4 of them are of P Cygni type, about 15% inverse P Cygni, about 25% double-peaked, about 1/3 pure absorption, and a few are single emission lines. Transformation of the profile from one type to another typically takes a few days. Although the line stays in absorption for extended intervals, only one high-velocity absorption event of the intensity reported by Kaufer et al. (1996a) was observed, in late 2006. Late in this event, Hα absorption occurred farther to the red than the red wing of a plausible photospheric absorption component, an indication of infalling material. In general, as the absorption events come to an end, the emission typically returns with an inverse P Cygni profile. The Hα profile class shows no obvious correlation with the radial velocity of C II λ6578, a photospheric absorption line.

  10. Are drug companies living up to their human rights responsibilities? Moving toward assessment.

    Directory of Open Access Journals (Sweden)

    Sofia Gruskin

    2010-09-01

    Full Text Available BACKGROUND TO THE DEBATE: The human rights responsibilities of drug companies have been considered for years by nongovernmental organizations, but were most sharply defined in a report by the UN Special Rapporteur on the right to health, submitted to the United Nations General Assembly in August 2008. The "Human Rights Guidelines for Pharmaceutical Companies in relation to Access to Medicines" include responsibilities for transparency, management, monitoring and accountability, pricing, and ethical marketing, and against lobbying for more protection in intellectual property laws, applying for patents for trivial modifications of existing medicines, inappropriate drug promotion, and excessive pricing. Two years after the release of the Guidelines, the PLoS Medicine Debate asks whether drug companies are living up to their human rights responsibilities. Sofia Gruskin and Zyde Raad from the Harvard School of Public Health say more assessment is needed of such responsibilities; Geralyn Ritter, Vice President of Global Public Policy and Corporate Responsibility at Merck & Co. argues that multiple stakeholders could do more to help States deliver the right to health; and Paul Hunt and Rajat Khosla introduce Mr. Hunt's work as the UN Special Rapporteur on the right to the highest attainable standard of health, regarding the human rights responsibilities of pharmaceutical companies and access to medicines.

  11. Are drug companies living up to their human rights responsibilities? The perspective of the former United Nations Special Rapporteur (2002-2008.

    Directory of Open Access Journals (Sweden)

    Paul Hunt

    2010-09-01

    Full Text Available BACKGROUND TO THE DEBATE: The human rights responsibilities of drug companies have been considered for years by nongovernmental organizations, but were most sharply defined in a report by the UN Special Rapporteur on the right to health, submitted to the United Nations General Assembly in August 2008. The "Human Rights Guidelines for Pharmaceutical Companies in relation to Access to Medicines" include responsibilities for transparency, management, monitoring and accountability, pricing, and ethical marketing, and against lobbying for more protection in intellectual property laws, applying for patents for trivial modifications of existing medicines, inappropriate drug promotion, and excessive pricing. Two years after the release of the Guidelines, the PLoS Medicine Debate asks whether drug companies are living up to their human rights responsibilities. Sofia Gruskin and Zyde Raad from the Harvard School of Public Health say more assessment is needed of such responsibilities; Geralyn Ritter, Vice President of Global Public Policy and Corporate Responsibility at Merck & Co. argues that multiple stakeholders could do more to help States deliver the right to health; and Paul Hunt and Rajat Khosla introduce Mr. Hunt's work as the UN Special Rapporteur on the right to the highest attainable standard of health, regarding the human rights responsibilities of pharmaceutical companies and access to medicines.

  12. The stimulatory effect of Pantoea sp. 3.5.1 on the seed germination, plant growth and development

    Directory of Open Access Journals (Sweden)

    L.R. Nigmatulina

    2016-04-01

    Full Text Available Recent years increasing pressure on the environment is extremely exacerbated by the increasing growth of the world population needs. According to world population prospects data [World Population Prospects: The 2015 Revision] human population will increase and by 2025 will estimate to reach approximately 8 billion people. That is why people needed to use herbicides, pesticides and fertilizers to increase agricultural productivity. But most of them are persistent environmental pollutants because of their resistance to degradation and remaining in the environment for years. It may accumulate to biohazard concentrations what leads to environment poisoning [Ritter et al., 2007]. At the same time application plant-growth promoting bacteria is environmentally friendly approach. Here we show that Pantoea sp. 3.5.1 capable to promote a strong plant growth. Also here we characterize main Pantoea sp. 3.5.1 plant growth promoting mechanisms. Thus Pantoea sp. 3.5.1 is discussed to show a great promise in development of environmentally save fertilizers.

  13. Are drug companies living up to their human rights responsibilities? The Merck perspective.

    Directory of Open Access Journals (Sweden)

    Geralyn S Ritter

    2010-09-01

    Full Text Available BACKGROUND TO THE DEBATE: The human rights responsibilities of drug companies have been considered for years by nongovernmental organizations, but were most sharply defined in a report by the UN Special Rapporteur on the right to health, submitted to the United Nations General Assembly in August 2008. The "Human Rights Guidelines for Pharmaceutical Companies in relation to Access to Medicines" include responsibilities for transparency, management, monitoring and accountability, pricing, and ethical marketing, and against lobbying for more protection in intellectual property laws, applying for patents for trivial modifications of existing medicines, inappropriate drug promotion, and excessive pricing. Two years after the release of the Guidelines, the PLoS Medicine Debate asks whether drug companies are living up to their human rights responsibilities. Sofia Gruskin and Zyde Raad from the Harvard School of Public Health say more assessment is needed of such responsibilities; Geralyn Ritter, Vice President of Global Public Policy and Corporate Responsibility at Merck & Co. argues that multiple stakeholders could do more to help States deliver the right to health; and Paul Hunt and Rajat Khosla introduce Mr. Hunt's work as the UN Special Rapporteur on the right to the highest attainable standard of health, regarding the human rights responsibilities of pharmaceutical companies and access to medicines.

  14. Para onde vai a Geografia?

    Directory of Open Access Journals (Sweden)

    Angélica Karina Dillenburg Horii

    2015-12-01

    Full Text Available O presente artigo aborda a evolução da Geografia enquanto pensamento científico, analisando seu objeto de estudo e suas categorias de análise durante todo o percurso da criação desse saber. Observa primeiramente a formação da Geografia Clássica, que teve seus princípios já instituídos na Antiguidade com Ptolomeu e Estrabão, desdobrando-se no período Iluminista com Ritter e Humboldt que fornecerão uma nova temporalidade a essa ciência. Atinge seu ápice na Modernidade Industrial com a racionalidade de Kant, onde Ratzel e La Blache utilizarão o determinismo e o possibilismo para constituir um discurso científico para a Geografia. Finaliza apontando a nova compreensão do mundo, conhecida como pós-modernismo por David Harvey (1992 ou por Milton Santos (1996 como Globalização, que junto a outros geógrafos e pesquisadores, indicam caminhos de análise dessa ciência na compreensão do seu objeto de estudo. Um diálogo entre os autores na construção do pensamento geográfico.

  15. COMMITTEES: SQM 2007 - International Conference On Strangeness In Quark Matter SQM 2007 - International Conference On Strangeness In Quark Matter

    Science.gov (United States)

    2008-04-01

    Local Organising Committee Ivan Králik (IEP SAS, Košice) Vojtěch Petráček (Czechoslovakia Technical University, Prague) Ján Pišút (Comenius University, Bratislava) Emanuele Quercigh (CERN) Karel Šafařík (CERN), Co-chair Ladislav v Sándor (IEP SAS, Košice), Co-chair Boris Tomášik (Mateja Bela University, Banská Bystrica) Jozef Urbán (UPJŠ Košice) International Advisory Committee Jörg Aichelin, Nantes Federico Antinori, Padova Tamás Biró, Budapest Peter Braun-Munzinger, GSI Jean Cleymans, Cape Town László Csernai, Bergen Timothy Hallman, BNL Huan Zhong Huang, UCLA Sonja Kabana, Nantes Roy A Lacey, Stony Brook Carlos Lourenço, CERN Yu-Gang Ma, Shanghai Jes Masden, Aarhus Yasuo Miake, Tsukuba Berndt Müller, Duke Grazyna Odyniec, LBNL Helmut Oeschler, Darmstadt Jan Rafelski, Arizona Hans Georg Ritter, LBNL Jack Sandweiss, Yale George S F Stephans, MIT Horst Stöcker, Frankfurt Thomas Ullrich, BNL Orlando Villalobos-Baillie, Birmingham William A Zajc, Columbia

  16. Leadership, self-efficacy, and student achievement

    Science.gov (United States)

    Grayson, Kristin

    This study examined the relationships between teacher leadership, science teacher self-efficacy, and fifth-grade science student achievement in diverse schools in a San Antonio, Texas, metropolitan school district. Teachers completed a modified version of the Leadership Behavior Description Question (LBDQ) Form XII by Stogdill (1969), the Science Efficacy and Belief Expectations for Science Teaching (SEBEST) by Ritter, Boone, and Rubba (2001, January). Students' scores on the Texas Assessment of Knowledge and Skills (TAKS) measured fifth-grade science achievement. At the teacher level of analysis multiple regressions showed the following relationships between teachers' science self-efficacy and teacher classroom leadership behaviors and the various teacher and school demographic variables. Predictors of teacher self efficacy beliefs included teacher's level of education, gender, and leadership initiating structure. The only significant predictor of teacher self-efficacy outcome expectancy was gender. Higher teacher self-efficacy beliefs predicted higher leadership initiating structure. At the school level of analysis, higher school levels of percentage of students from low socio-economic backgrounds and higher percentage of limited English proficient students predicted lower school student mean science achievement. These findings suggest a need for continued research to clarify relationships between teacher classroom leadership, science teacher self-efficacy, and student achievement especially at the teacher level of analysis. Findings also indicate the importance of developing instructional methods to address student demographics and their needs so that all students, despite their backgrounds, will achieve in science.

  17. Use and knowledge of Cactaceae in Northeastern Brazil

    Science.gov (United States)

    2013-01-01

    Background This study aimed to record the use, and knowledge that residents from São Francisco community (Paraiba, Brazil) have regarding the Cactaceae. Methods Semi-structured interviews were carried out with 118 informants; 50 men and 68 women. The cacti cited in this study were organised into use categories and use values were calculated. Differences in the values applied to species and use categories by men and women were compared via a G test (Williams). Results The nine species identified were: Cereus jamacaru DC., Melocactus bahiensis (Brtitton & Rose) Luetzelb., Nopalea cochenillifera (L.) Salm-Dyck., Opuntia ficus indica (L.) Mill, Opuntia stricta (Haw.) Haw., Pilosocereus gounellei (F.A.C. Weber) Byles & Rowley, Pilosocereus pachycladus F. Ritter, Tacinga inamoena (K. Schum) N.P. Taylor & Stuppy, Tacinga palmadora (Britton & Rose) N.P. Taylor & Stuppy. In total, 1,129 use citations were recorded, divided into 11 categories. The use value categories with the highest scores were forage (0.42), food (0.30) and construction (building) (0.25). P. pachycladus showed the greatest use value, versatility and number of plant parts used. Conclusion The survey showed that the Cactaceae is extremely important for several uses and categories attributed to different species. Apart from contributing to the ethnobotanical knowledge of the Cactaceae, another important focus of this study was to reinforce the necessity for further studies that record the traditional knowledge about this plant family, which has been lost in younger generations. PMID:23981911

  18. Chaetognatha of the Brazil-Malvinas (Falkland confluence: distribution and associations

    Directory of Open Access Journals (Sweden)

    Alina M. Crelier

    Full Text Available The planktonic chaetognaths from the Brazil-Malvinas (Falkland confluence, extending between 36º 30' - 50º 5' S and 60º 33' - 41º 7' W, were studied. Ten species were found: Eukrohnia hamata (Möbius, 1875 (Eukrohniidae, Pterosagitta draco (Krohn, 1853 (Pterosagittidae, Sagitta enflata Grassi, 1881, Sagitta gazellae Ritter-Zahony, 1909, Sagitta hexaptera d´Orbigny, 1834, Sagitta lyra Krohn, 1853, Sagitta minima Grassi, 1881, Sagitta planctonis Steinhaus, 1896, Sagitta serratodentata Krohn, 1853, and Sagitta tasmanica Thomson, 1947 (Sagittidae. Sagitta gazellae was the most abundant species followed by E. hamata, S. tasmanica and S. serratodentata. The association analysis among the different species, salinity and temperature revealed two groups of species, one related to higher salinities and warmer waters (P. draco, S. hexaptera and S. serratodentata and the other to lower salinities and colder waters (E. hamata, S. gazellae and S. tasmanica. The fact that P. draco and S. hexaptera, formerly defined as warm-water species, appeared further south than previously reported might be related to the existence of warm core eddies up to 46º S in September and October 1988.

  19. The Cyborg Astrobiologist: Image Compression for Geological Mapping and Novelty Detection

    Science.gov (United States)

    McGuire, P. C.; Bonnici, A.; Bruner, K. R.; Gross, C.; Ormö, J.; Smosna, R. A.; Walter, S.; Wendt, L.

    2013-09-01

    We describe an image-comparison technique of Heidemann and Ritter [4,5] that uses image compression, and is capable of: (i) detecting novel textures in a series of images, as well as of: (ii) alerting the user to the similarity of a new image to a previously-observed texture. This image-comparison technique has been implemented and tested using our Astrobiology Phone-cam system, which employs Bluetooth communication to send images to a local laptop server in the field for the image-compression analysis. We tested the system in a field site displaying a heterogeneous suite of sandstones, limestones, mudstones and coalbeds. Some of the rocks are partly covered with lichen. The image-matching procedure of this system performed very well with data obtained through our field test, grouping all images of yellow lichens together and grouping all images of a coal bed together, and giving a 91% accuracy for similarity detection. Such similarity detection could be employed to make maps of different geological units. The novelty-detection performance of our system was also rather good (a 64% accuracy). Such novelty detection may become valuable in searching for new geological units, which could be of astrobiological interest. By providing more advanced capabilities for similarity detection and novelty detection, this image-compression technique could be useful in giving more scientific autonomy to robotic planetary rovers, and in assisting human astronauts in their geological exploration.

  20. LA OBSERVACIÓN E INTERPRETACIÓN DEL PAISAJE

    Directory of Open Access Journals (Sweden)

    Antonio Sanchez ogallar

    1997-12-01

    Full Text Available La contribución de la Didáctica de laGeografía a la enseñanza-aprendizaje de losnuevos contenidos relativos al paisaje en laEducación Obligatoria debe partir de una profundareflexión sobre los dos grandes pilaresen los que se asienta la reforma establecida porla LOGSE: las fuentes del currículo y los elementosdel mismo.La fuente sociocultural, que nos sitúa en lasactuales coordenadas espacio-temporales, nosinvita al análisis de la organización social, losvalores imperantes y la concienciación sobreel desarrollo tecnológico a la búsqueda de undiagnostico sobre los problemas ambientalesque justifica la necesidad de un desarrollo sostenibley a considerar el proceso educativocomo pieza clave para preservar y mejorar loque Ritter llamó "el cuerpo de la Humanidad",refiriéndose a la Tierra, de la que los hombresserían "el alma"(ESTÉBANEZ 1982

  1. The Cyborg Astrobiologist: Matching of Prior Textures by Image Compression for Geological Mapping and Novelty Detection

    CERN Document Server

    McGuire, P C; Bruner, K R; Gross, C; Ormö, J; Smosna, R A; Walter, S; Wendt, L

    2013-01-01

    (abridged) We describe an image-comparison technique of Heidemann and Ritter that uses image compression, and is capable of: (i) detecting novel textures in a series of images, as well as of: (ii) alerting the user to the similarity of a new image to a previously-observed texture. This image-comparison technique has been implemented and tested using our Astrobiology Phone-cam system, which employs Bluetooth communication to send images to a local laptop server in the field for the image-compression analysis. We tested the system in a field site displaying a heterogeneous suite of sandstones, limestones, mudstones and coalbeds. Some of the rocks are partly covered with lichen. The image-matching procedure of this system performed very well with data obtained through our field test, grouping all images of yellow lichens together and grouping all images of a coal bed together, and giving a 91% accuracy for similarity detection. Such similarity detection could be employed to make maps of different geological unit...

  2. 2009 AMCA Memorial Lecture Honoree: Dr. Chester Lamar Meek.

    Science.gov (United States)

    Connelly, C Roxanne

    2009-09-01

    Chester Lamar Meek (1944-2000), 2009 AMCA Memorial Lecture Honoree, was husband to Sharon Kay Meek, father of Bradley Lamar and Jody Keith, and a member of the faculty of Louisiana State University for 25 years when he passed away on June 27, 2000, while conducting field research on mosquitoes in Cleveland, Mississippi. Dr. Meek was born in Monticello, Arkansas, and attended Ouachita Baptist University, University of Arkansas, and Texas A&M University, where he took his B.S., M.S., and Ph.D., respectively. He was an expert in the biology and control of rice-field mosquitoes and in forensic entomology. He served in the medical service corps of the US Army, authored or co-authored over 65 scientific publications, and was mentor to graduate students in medical and forensic entomology. Dr. Meek was a member of the Louisiana Mosquito Control Association, the Texas Mosquito Control Association, the American Mosquito Control Association, the Entomological Society of America, the American Registry of Professional Entomologists, and the Society for Vector Ecology. He received the American Mosquito Control Association's awards for Meritorious Service (1986) and the Memorial Lectureship Award (1991) and was recognized for his service by the Louisiana Mosquito Control Association with the 1989 Hathaway-Ritter Distinguished Achievement award.

  3. SPECTROSCOPIC AND PHOTOMETRIC VARIABILITY IN THE A0 SUPERGIANT HR 1040

    Energy Technology Data Exchange (ETDEWEB)

    Corliss, David J.; Morrison, Nancy D. [Department of Physics and Astronomy, The University of Toledo, Toledo, OH 43606 (United States); Adelman, Saul J., E-mail: david.corliss@wayne.edu [Department of Physics, The Citadel, 171 Moultrie Street, Charleston, SC 29409 (United States)

    2015-12-15

    A time-series analysis of spectroscopic and photometric observables of the A0 Ia supergiant HR 1040 has been performed, including equivalent widths, radial velocities, and Strömgren photometric indices. The data, obtained from 1993 through 2007, include 152 spectroscopic observations from the Ritter Observatory 1 m telescope and 269 Strömgren photometric observations from the Four College Automated Photoelectric Telescope. Typical of late B- and early A-type supergiants, HR 1040 has a highly variable Hα profile. The star was found to have an intermittent active phase marked by correlation between the Hα absorption equivalent width and blue-edge radial velocity and by photospheric connections observed in correlations to equivalent width, second moment and radial velocity in Si ii λλ6347, 6371. High-velocity absorption (HVA) events were observed only during this active phase. HVA events in the wind were preceded by photospheric activity, including Si ii radial velocity oscillations 19–42 days prior to onset of an HVA event and correlated increases in Si ii W{sub λ} and second moment from 13 to 23 days before the start of the HVA event. While increases in various line equivalent widths in the wind prior to HVA events have been reported in the past in other stars, our finding of precursors in enhanced radial velocity variations in the wind and at the photosphere is a new result.

  4. Elasticity of calcium and calcium-sodium amphiboles

    Science.gov (United States)

    Brown, J. Michael; Abramson, Evan H.

    2016-12-01

    Measurements of single-crystal elastic moduli under ambient conditions are reported for nine calcium to calcium-sodium amphiboles that lie in the composition range of common crustal constituents. Velocities of body and surface acoustic waves measured by Impulsive Stimulated Light Scattering (ISLS) were inverted to determine the 13 moduli characterizing these monoclinic samples. Moduli show a consistent pattern: C33 > C22 > C11 and C23 > C12 > C13 and C44 > C55 ∼ C66 and for the uniquely monoclinic moduli, |C35| ≫ C46 ∼ |C25| > |C15| ∼ 0. Most of the compositionally-induced variance of moduli is associated with aluminum and iron content. Seven moduli (C11C12C13C22C44C55C66) increase with increasing aluminum while all diagonal moduli decrease with increasing iron. Three moduli (C11, C13 and C44) increase with increasing sodium and potassium occupancy in A-sites. The uniquely monoclinic moduli (C15C25 and C35) have no significant compositional dependence. Moduli associated with the a∗ direction (C11C12C13C55 and C66) are substantially smaller than values associated with structurally and chemically related clinopyroxenes. Other moduli are more similar for both inosilicates. The isotropically averaged adiabatic bulk modulus does not vary with iron content but increases with aluminum content from 85 GPa for tremolite to 99 GPa for pargasite. Increasing iron reduces while increasing aluminum increases the isotropic shear modulus which ranges from 47 GPa for ferro-actinolite to 64 GPa for pargasite. These results exhibit far greater anisotropy and higher velocities than apparent in earlier work. Quasi-longitudinal velocities are as fast as ∼9 km/s and (intermediate between the a∗- and c-axes) are as slow as ∼6 km/s. Voigt-Reuss-Hill averaging based on prior single crystal moduli resulted in calculated rock velocities lower than laboratory measurements, leading to adoption of the (higher velocity) Voigt bound. Thus, former uses of the upper Voigt bound can

  5. Measurements of linestrengths, N2-, Ar-, He- and self-broadening coefficients of acetylene in the ν4+ν5 combination band using a cw quantum cascade laser

    KAUST Repository

    Sajid, Muhammad Bilal

    2014-11-01

    Linestrengths, N2-, Ar-, He- and self-broadening coefficients of acetylene have been measured at 296K in the P branch of the ν4+ν5 combination band for 25 rotational transitions. The effect of gas temperature is studied over 296-683K for five transitions to allow the determination of the temperature dependent exponent n for N2- and Ar-broadening coefficients. These measurements were performed using a continuous-wave quantum cascade laser (cw-QCL) operating over 1253-1310cm-1. Spectroscopic parameters were obtained by fitting absorption spectra using Voigt, Galatry and Rautian profiles. Linestrength and broadening results are compared with previous studies available in literature for the ν4+ν5 combination band and other vibrational bands of acetylene. © 2014 Elsevier Ltd.

  6. Effective negative refractive index in ferromagnet-semiconductor superlattices.

    Science.gov (United States)

    Tarkanyan, Roland H; Niarchos, Dimitris G

    2006-06-12

    Problem of anomalous refraction of electromagnetic waves is analyzed in a superlattice which consists of alternating layers of ferromagnetic insulator and nonmagnetic semiconductor. Effective permittivity and permeability tensors are derived in the presence of an external magnetic field parallel to the plane of the layers. It is shown that in the case of the Voigt configuration, the structure behaves as a left-handed medium with respect to TE-type polarized wave, in the low-frequency region of propagation. The relative orientation of the Poynting vector and the refractive wave vector is examined in different frequency ranges. It is shown that the frequency region of existence for the backward mode can be changed using external magnetic field as tuning parameter.

  7. Parametric imaging of viscoelasticity using optical coherence elastography

    Science.gov (United States)

    Wijesinghe, Philip; McLaughlin, Robert A.; Sampson, David D.; Kennedy, Brendan F.

    2015-03-01

    We demonstrate imaging of soft tissue viscoelasticity using optical coherence elastography. Viscoelastic creep deformation is induced in tissue using step-like compressive loading and the resulting time-varying deformation is measured using phase-sensitive optical coherence tomography. From a series of co-located B-scans, we estimate the local strain rate as a function of time, and parameterize it using a four-parameter Kelvin-Voigt model of viscoelastic creep. The estimated viscoelastic strain and time constant are used to visualize viscoelastic creep in 2D, dual-parameter viscoelastograms. We demonstrate our technique on six silicone tissue-simulating phantoms spanning a range of viscoelastic parameters. As an example in soft tissue, we report viscoelastic contrast between muscle and connective tissue in fresh, ex vivo rat gastrocnemius muscle and mouse abdominal transection. Imaging viscoelastic creep deformation has the potential to provide complementary contrast to existing imaging modalities, and may provide greater insight into disease pathology.

  8. Lubrication of soft viscoelastic solids

    CERN Document Server

    Pandey, Anupam; Venner, Kees; Snoeijer, Jacco

    2015-01-01

    Lubrication flows appear in many applications in engineering, biophysics, and in nature. Separation of surfaces and minimisation of friction and wear is achieved when the lubrication fluid builds up a lift force. In this paper we analyse soft lubricated contacts by treating the solid walls as viscoelastic: soft materials are typically not purely elastic, but dissipate energy under dynamical loading conditions. We present a method for viscoelastic lubrication and focus on three canonical examples, namely Kelvin-Voigt-, Standard Linear-, and Power Law-rheology. It is shown how the solid viscoelasticity affects the lubrication process when the timescale of loading becomes comparable to the rheological timescale. We derive asymptotic relations between lift force and sliding velocity, which give scaling laws that inherit a signature of the rheology. In all cases the lift is found to decrease with respect to purely elastic systems.

  9. Quantum-Limited Spectroscopy

    CERN Document Server

    Truong, Gar-Wing; May, Eric F; Stace, Thomas M; Luiten, Andre N

    2015-01-01

    Spectroscopy has an illustrious history delivering serendipitous discoveries and providing a stringent testbed for new physical predictions, including applications from trace materials detection, to understanding the atmospheres of stars and planets, and even constraining cosmological models. Reaching fundamental-noise limits permits optimal extraction of spectroscopic information from an absorption measurement. Here we demonstrate a quantum-limited spectrometer that delivers high-precision measurements of the absorption lineshape. These measurements yield a ten-fold improvement in the accuracy of the excited-state (6P$_{1/2}$) hyperfine splitting in Cs, and reveals a breakdown in the well-known Voigt spectral profile. We develop a theoretical model that accounts for this breakdown, explaining the observations to within the shot-noise limit. Our model enables us to infer the thermal velocity-dispersion of the Cs vapour with an uncertainty of 35ppm within an hour. This allows us to determine a value for Boltzm...

  10. Doppler broadening thermometry of acetylene and accurate measurement of the Boltzmann constant.

    Science.gov (United States)

    Hashemi, R; Povey, C; Derksen, M; Naseri, H; Garber, J; Predoi-Cross, A

    2014-12-07

    In this paper, we present accurate measurements of the fundamental Boltzmann constant based on a line-shape analysis of acetylene spectra in the ν1 + ν3 band recorded using a tunable diode laser. Experimental spectra recorded at low pressures (0.25 - 9 Torr), have been analyzed using a Speed Dependent Voigt model that takes into account the molecular speed dependence effects. This line-shape model reproduces the experimental data with good accuracy and allows us to determine precise line-shape parameters for the P(25) transition of the ν1 + ν3 band. From the recorded spectra we obtained the Doppler-width and then determined the Boltzmann constant, k(B).

  11. A Perturbation Result for Dynamical Contact Problems

    Institute of Scientific and Technical Information of China (English)

    Corinna Klapproth; Peter Deuflhard; Anton Schiela

    2009-01-01

    This paper is intended to be a first step towards the continuous dependence of dynamical contact problems on the initial data as well as the uniqueness of a solution. Moreover, it provides the basis for a proof of the convergence of popular time integration schemes as the Newmark method. We study a frictionless dynamical contact problem between both linearly elastic and viscoelastic bodies which is formulated via the Signorini contact conditions. For viscoelastic materials fulfilling the Kelvin-Voigt constitutive law, we find a characterization of the class of problems which satisfy a perturbation result in a non-trivial mix of norms in function space. This characterization is given in the form of a stability condition on the contact stresses at the contact boundaries. Furthermore, we present perturbation results for two well-established approximations of the classical Signorini condition: The Signorini condition formulated in velocities and the model of normal compliance, both satisfying even a sharper version of our stability condition.

  12. Influence of He+ long-time irradiation on silica luminescence spectrum

    Science.gov (United States)

    Zhurenko, V.; Kalantaryan, O.; Kononenko, S.; Mysiura, I.; Barannik, E.

    2017-09-01

    The paper deals with experimental investigation of 420 keV He+ dose dependence of silica (medium OH-group contents) luminescence. It was founded that experimental spectra were good fitted by two Voigt peaks centered in 2.7 and 1.9 eV. The absorption dose growth influenced on silica ionoluminescence spectra due to increase of radiation defects. We compared the obtained results with 420 keV hydrogen ion irradiation data for the same samples. It was shown that relative intensity of red band correlated with specific energy losses and effective charge of ions in silica. The theoretical simulation of helium ion implantation and intrinsic defect dynamics was performed. The dependence of ionoluminescence intensity on observation angle was measured.

  13. Principal Resonance of Parametrically Excited Moving Viscoelastic Belts with Geometrical Nonlinearity

    Institute of Scientific and Technical Information of China (English)

    侯之超; 祖武争

    2004-01-01

    Nonlinear dynamic analysis is performed on moving belts subjected to geometric nonlinearity and initial tension fluctuation.To incorporate more accurately the damping mechanism of belt material, linear viscoelastic models are adopted in a unified form of differential operators.To circumvent high-order differential vibration equation of time-varying coefficients and with gyroscopic and nonlinear terms, where analytical solution is almost impossible, a systematic approach is presented by reforming the motion equation and directly using the method of multiple scales.To exemplify the procedure, the solutions at principal resonance are obtained and their stability conditions are derived for employing a Kelvin-Voigt model to reflect the property of the belt material.The solutions and stability conditions successfully reduce to those for using Kelvin model and elastic model, which validate the present approaches.Numerical simulations highlight the effects of tension fluctuations and translating speeds on the stability of the belt vibration.

  14. Verification and comparison of four numerical schemes for a 1D viscoelastic blood flow model.

    Science.gov (United States)

    Wang, Xiaofei; Fullana, Jose-Maria; Lagrée, Pierre-Yves

    2015-01-01

    A reliable and fast numerical scheme is crucial for the 1D simulation of blood flow in compliant vessels. In this paper, a 1D blood flow model is incorporated with a Kelvin-Voigt viscoelastic arterial wall. This leads to a nonlinear hyperbolic-parabolic system, which is then solved with four numerical schemes, namely: MacCormack, Taylor-Galerkin, monotonic upwind scheme for conservation law and local discontinuous Galerkin. The numerical schemes are tested on a single vessel, a simple bifurcation and a network with 55 arteries. The numerical solutions are checked favorably against analytical, semi-analytical solutions or clinical observations. Among the numerical schemes, comparisons are made in four important aspects: accuracy, ability to capture shock-like phenomena, computational speed and implementation complexity. The suitable conditions for the application of each scheme are discussed.

  15. Phase-conjugate resonant holographic interferometry applied to NH concentration measurements in a 2D diffusion flame

    Energy Technology Data Exchange (ETDEWEB)

    Tzannis, A.P.; Beaud, P.; Frey, H.M.; Gerber, T.; Mischler, B.; Radi, P.P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Resonant Holographic Interferometry is a method based on the anomalous dispersion of light having a frequency close to an electronic transition of a molecule. We propose a novel single-laser, two-colour setup for recording resonant holograms and apply it to 2D species concentration measurements. The second colour is generated by optical phase-conjugation from Stimulated Brillouin scattering in a cell. Phase-Conjugate Resonant Holographic Interferometry (PCRHI) is demonstrated in a 2D NH{sub 3}/O{sub 2} flame yielding interferograms that contain information on the NH radical distribution in the flame. Experimental results are quantified by applying a numerical computation of the Voigt profiles. (author) 1 fig., 3 refs.

  16. Generation and characterization of OH and O radicals by atmospheric pressure steam/oxygen plasma

    CERN Document Server

    Roy, N C; Alam, M K; Talukder, M R

    2016-01-01

    Atmospheric pressure steam/oxygen plasma is generated by a 88 Hz, 6kV AC power supply. The properties of the produced plasma are investigated by optical emission spectroscopy (OES). The relative intensity, rotational, vibrational, excitation temperatures and electron density are studied as function of applied voltage, electrode spacing and oxygen flow rate. The rotational and vibrational temperatures are determined simulating the bands with the aid of LIFBASE simulation software. The excitation temperature is obtained from the CuI transition taking non-thermal equilibrium condition into account employing intensity ratio method. The electron density is approximated from the H_{\\alpha} Stark broadening using the Voigt profile fitting method. It is observed that the rotational and vibrational temperatures are decreased with increasing electrode spacing and O2 flow rate, but increased with the applied voltage. The excitation temperature is found to increase with increasing applied voltage and O2 flow rate, but de...

  17. Vibrations of a Simply Supported Beam with a Fractional Viscoelastic Material Model – Supports Movement Excitation

    Directory of Open Access Journals (Sweden)

    Jan Freundlich

    2013-01-01

    Full Text Available The paper presents vibration analysis of a simply supported beam with a fractional order viscoelastic material model. The Bernoulli-Euler beam model is considered. The beam is excited by the supports movement. The Riemann – Liouville fractional derivative of order 0 α ⩽ 1 is applied. In the first stage, the steady-state vibrations of the beam are analyzed and therefore the Riemann – Liouville fractional derivative with lower terminal at −∞ is assumed. This assumption simplifies solution of the fractional differential equations and enables us to directly obtain amplitude-frequency characteristics of the examined system. The characteristics are obtained for various values of fractional derivative of order α and values of the Voigt material model parameters. The studies show that the selection of appropriate damping coefficients and fractional derivative order of damping model enables us to fit more accurately dynamic characteristic of the beam in comparison with using integer order derivative damping model.

  18. Theory of wave propagation in magnetized near-zero-epsilon metamaterials: evidence for one-way photonic states and magnetically switched transparency and opacity.

    Science.gov (United States)

    Davoyan, Arthur R; Engheta, Nader

    2013-12-20

    We study propagation of transverse-magnetic electromagnetic waves in the bulk and at the surface of a magnetized epsilon-near-zero (ENZ) medium in a Voigt configuration. We reveal that in a certain range of material parameters novel regimes of wave propagation emerge; we show that the transparency of the medium can be altered with the magnetization leading either to magnetically induced Hall opacity or Hall transparency of the ENZ. In our theoretical study, we demonstrate that surface waves at the interface between either a transparent or an opaque Hall medium and a homogeneous medium may, under certain conditions, be predominantly one way. Moreover, we predict that one-way photonic surface states may exist at the interface of an opaque Hall ENZ and a regular metal, giving rise to the possibility for backscattering immune wave propagation and isolation.

  19. Synthesis of hydroxyapatite and structural refinement by X-ray diffraction; Sintese da hidroxiapatita e refinamento estrutural por difracao de raios-X

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Jorge Correa de [Universidade do Estado do Rio de Janeiro (UERJ), Sao Goncalo, RJ (Brazil). Faculdade de Formacao de Professores; Sena, Lidia [Instituto Nacional de Metrologia, Normalizacao e Qualidade Industrial (INMETRO), Duque de Caxias, RJ (Brazil). Div. de Metrologia de Materiais; Bastos, Ivan Napoleao [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Inst. Politecnico]. E-mail: jcaraujo@iprj.uerj.br; Soares, Gloria Dulce de Almeida [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2007-07-01

    A sample of hydroxyapatite was synthesized and its crystalline structure was analyzed by X-ray diffraction by means of the Rietveld method. Two functions were used to fit the peak profiles, modified Voigt (TCHZ) and Pearson VII. The occupational factors and lattice parameters obtained by both models show that the sample does not contain relevant cationic substitutions. The interatomic distances from Ca1 to oxygens O1, O2 and O3 were adequate for a pure hydroxyapatite without defect at site Ca1. Besides, the use of multiple lines in planes (300) and (002) associated with the model Pearson VII resulted in good agreement with the TCHZ model with respect to the size-strain effects with an ellipsoidal shape of crystallites. In conclusion, the procedures adopted in the synthesis of hydroxyapatite produced a pure and crystalline material. The experimental results of transmission electron microscopy confirmed the predicted shape of crystals. (author)

  20. Investigating the Metallicity Evolution of Sub-damped Lyman alpha Systems

    Science.gov (United States)

    Konchady, Tarini; Jorgenson, Regina

    2017-01-01

    A clear understanding of the production and build up of metals across cosmic time is a key ingredient to any theory of galaxy formation and evolution. We present chemical abundance measurements for a sample of ~20 sub-damped Lyman alpha systems (subDLAs) detected in the absorption spectra of high redshift quasars taken by the Echellette Spectrograph and Imager (ESI) on the Keck II telescope. The sample contains absorbers with neutral hydrogen column densities of 1019.0 Metal line column densities were measured using the apparent optical depth method while neutral hydrogen column densities were measured via Voigt profile fitting. We compare our measurements to those of DLAs and subDLAs from the literature to investigate the potential differences in metallicity evolution between these types of galaxies.

  1. B Free Finite Element Approach for Saturated Porous Media: Consolidation

    Directory of Open Access Journals (Sweden)

    M. M. Stickle

    2016-01-01

    Full Text Available The B free finite element approach is applied to the governing equations describing the consolidation process in saturated poroelastic medium with intrinsically incompressible solid and fluid phases. Under this approach, where Voigt notation is avoided, the finite element equilibrium equations and the linearization of the coupled governing equations are fully derived using tensor algebra. In order to assess the B free approach for the consolidation equations, direct comparison with analytical solution of the response of a homogeneous and isotropic water-saturated poroelastic finite column under harmonic load is presented. The results illustrate the capability of this finite element approach of reproducing accurately the response of quasistatic phenomena in a saturated porous medium.

  2. Consistent treatment of viscoelastic effects at junctions in one-dimensional blood flow models

    Science.gov (United States)

    Müller, Lucas O.; Leugering, Günter; Blanco, Pablo J.

    2016-06-01

    While the numerical discretization of one-dimensional blood flow models for vessels with viscoelastic wall properties is widely established, there is still no clear approach on how to couple one-dimensional segments that compose a network of viscoelastic vessels. In particular for Voigt-type viscoelastic models, assumptions with regard to boundary conditions have to be made, which normally result in neglecting the viscoelastic effect at the edge of vessels. Here we propose a coupling strategy that takes advantage of a hyperbolic reformulation of the original model and the inherent information of the resulting system. We show that applying proper coupling conditions is fundamental for preserving the physical coherence and numerical accuracy of the solution in both academic and physiologically relevant cases.

  3. A Constrained Genetic Algorithm with Adaptively Defined Fitness Function in MRS Quantification

    Science.gov (United States)

    Papakostas, G. A.; Karras, D. A.; Mertzios, B. G.; Graveron-Demilly, D.; van Ormondt, D.

    MRS Signal quantification is a rather involved procedure and has attracted the interest of the medical engineering community, regarding the development of computationally efficient methodologies. Significant contributions based on Computational Intelligence tools, such as Neural Networks (NNs), demonstrated a good performance but not without drawbacks already discussed by the authors. On the other hand preliminary application of Genetic Algorithms (GA) has already been reported in the literature by the authors regarding the peak detection problem encountered in MRS quantification using the Voigt line shape model. This paper investigates a novel constrained genetic algorithm involving a generic and adaptively defined fitness function which extends the simple genetic algorithm methodology in case of noisy signals. The applicability of this new algorithm is scrutinized through experimentation in artificial MRS signals interleaved with noise, regarding its signal fitting capabilities. Although extensive experiments with real world MRS signals are necessary, the herein shown performance illustrates the method's potential to be established as a generic MRS metabolites quantification procedure.

  4. Direct Insights into Observational Absorption Line Analysis Methods of the Circumgalactic Medium Using Cosmological Simulations

    CERN Document Server

    Churchill, Christopher W; Trujillo-Gomez, Sebastian; Kacprzak, Glenn G; Klypin, Anatoly

    2014-01-01

    We study the circumgalactic medium (CGM) of a z=0.54 simulated dwarf galaxy using hydroART simulations. We present our analysis methods, which emulate observations, including objective absorption line detection, apparent optical depth (AOD) measurements, Voigt profile (VP) decomposition, and ionization modelling. By comparing the inferred CGM gas properties from the absorption lines directly to the gas selected by low ionization HI and MgII, and by higher ionization CIV and OVI absorption, we examine how well observational analysis methods recover the "true" properties of CGM gas. In this dwarf galaxy, low ionization gas arises in kiloparsec "cloud" structures, but high ionization gas arises in multiple extended structures spread over 100 kpc; due to complex velocity fields, highly separated structures give rise to absorption at similar velocities. We show that AOD and VP analysis fails to accurately characterize the spatial, kinematic, and thermal conditions of high ionization gas. We find that HI absorption...

  5. Time-Resolved Measurement of the C_2 ^1AΠ u State Population Following Photodissociation of the S_1 State of Acetylene Using Frequency-Modulation Spectroscopy

    Science.gov (United States)

    Du, Zhenhui; Jiang, Jun; Field, Robert W.

    2017-06-01

    The excited-state population of the C_2 ^1AΠ_u state produced in photolysis of S_1 acetylene was investigated. The pulsed UV laser (216.5 nm) excites acetylene into J=8 e-symmetry level of the S_1 3^4 level, and subsequently dissociates the S_1 acetylene into C_2 fragments. A frequency-modulated near-infrared probe laser beam is used to detect the C_2 population in the ^1AΠ_u state. The sensitivity and the fast response of the experimental setup has been verified by I_2 excited state measurements. The setup will be used to record the C_2 A-X transitions, which are fitted with a Voigt function. The derived lineshape and line intensities will be analyzed, and we will use the information to calculate the A state populations of C_2 and map the populations with time-resolution following the photolysis.

  6. Fluid identification in tight sandstone reservoirs based on a new rock physics model

    Science.gov (United States)

    Sun, Jianmeng; Wei, Xiaohan; Chen, Xuelian

    2016-08-01

    To identify pore fluids, we establish a new rock physics model named the tight sandstone dual-porosity model based on the Voigt-Reuss-Hill model, approximation for the Xu-White model and Gassmann’s equation to predict elastic wave velocities. The modeling test shows that predicted sonic velocities derived from this rock physics model match well with measured ones from logging data. In this context, elastic moduli can be derived from the model. By numerical study and characteristic analyzation of different elastic properties, a qualitative fluid identification method based on Poisson’s ratio and the S-L dual-factor method based on synthetic moduli is proposed. Case studies of these two new methods show the applicability in distinguishing among different fluids and different layers in tight sandstone reservoirs.

  7. Elastic properties of antiperovskite-type Ni-rich nitrides MNNi 3 (M=Zn, Cd, Mg, Al, Ga, In, Sn, Sb, Pd, Cu, Ag and Pt) as predicted from first-principles calculations

    Science.gov (United States)

    Bannikov, V. V.; Shein, I. R.; Ivanovskii, A. L.

    2010-11-01

    We have performed accurate ab initio total energy calculations using the full-potential linearized augmented plane wave (FP-LAPW) method with the generalized gradient approximation (GGA) for the exchange-correlation potential to systematically investigate elastic properties of 12 synthesized and hypothetical cubic antiperovskite-type Ni-rich nitrides MNNi 3, where M are Zn, Cd, Mg, Al, Ga, In, Sn, Sb, Pd, Cu, Ag and Pt. As a result, the optimized lattice parameters, independent elastic constants ( Cij), bulk-, shear- and tetragonal shear moduli, Cauchy’s pressure and some indexes of elastic anisotropy, as well as the numerical estimations of Young’s modulus, Poisson’s ratio and Pugh's indicator of brittle/ductile behavior for the corresponding polycrystalline MNNi 3 (in the Voigt-Reuss-Hill approximation) were obtained and analyzed in comparison with the available theoretical and experimental data.

  8. Elastic properties of antiperovskite-type Ni-rich nitrides MNNi{sub 3} (M=Zn, Cd, Mg, Al, Ga, In, Sn, Sb, Pd, Cu, Ag and Pt) as predicted from first-principles calculations

    Energy Technology Data Exchange (ETDEWEB)

    Bannikov, V.V.; Shein, I.R. [Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg (Russian Federation); Ivanovskii, A.L., E-mail: ivanovskii@ihim.uran.r [Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 620990 Ekaterinburg (Russian Federation)

    2010-11-15

    We have performed accurate ab initio total energy calculations using the full-potential linearized augmented plane wave (FP-LAPW) method with the generalized gradient approximation (GGA) for the exchange-correlation potential to systematically investigate elastic properties of 12 synthesized and hypothetical cubic antiperovskite-type Ni-rich nitrides MNNi{sub 3}, where M are Zn, Cd, Mg, Al, Ga, In, Sn, Sb, Pd, Cu, Ag and Pt. As a result, the optimized lattice parameters, independent elastic constants (C{sub ij}), bulk-, shear- and tetragonal shear moduli, Cauchy's pressure and some indexes of elastic anisotropy, as well as the numerical estimations of Young's modulus, Poisson's ratio and Pugh's indicator of brittle/ductile behavior for the corresponding polycrystalline MNNi{sub 3} (in the Voigt-Reuss-Hill approximation) were obtained and analyzed in comparison with the available theoretical and experimental data.

  9. Switching and propagation of magneto-plasmon-polaritons in magnetic slot waveguides and cavities

    CERN Document Server

    Nikolova, D

    2013-01-01

    The dispersion relations for surface plasmon-polaritons propagating in the Voigt geometry in a metal-insulator-metal waveguide with a magneto-optically active dielectric medium are derived. The symmetry between the upper and lower interfaces is broken by the introduction of the magnetic field; the balance between the field distributions on the two interfaces can be controlled by the applied field. This control is illustrated by finite-element method numerical simulations of the field distributions around a point dipole placed in the centre of the short waveguide; it is shown that both the total emission of radiation from the cavity and the distribution of the far-field radiation can be strongly modified by tuning the magnetisation of the waveguide. This raises the novel possibility of using magnetic fields to control light propagation in nanostructures.

  10. Intensities, broadening and narrowing parameters in the ν3 band of methane

    KAUST Repository

    Es-sebbar, Et-touhami

    2014-12-01

    The P-branch of methane\\'s ν3 band is probed to carry out an extensive study of the 2905-2908cm-1 infrared spectral region. Absolute line intensities as well as N2-, O2-, H2-, He-, Ar- and CO2-broadening coefficients are determined for nine transitions at room temperature. Narrowing parameters due to the Dicke effect have also been investigated. A narrow emission line-width (~0.0001cm-1) difference-frequency-generation (DFG) laser system is used as the tunable light source. To retrieve the CH4 spectroscopic parameters, Voigt and Galatry profiles were used to simulate the measured line shape of the individual transitions.

  11. Absolute Line Intensities in the 2nu3 Band of 16O12C32S

    Science.gov (United States)

    Bermejo; Domenech; Santos; Bouanich; Blanquet

    1997-09-01

    The strengths of 100 lines in the 2nu3 band of 16O12C32S have been measured at high resolution in the spectral range 4069-4118 cm-1, using a tunable difference-frequency laser spectrometer. These intensities were obtained by fitting Voigt profiles to the measured shapes of the lines. The vibrational transition moment [(2.141 ± 0.020) x 10(-2) D] and the absolute intensity (16.19 ± 0.24 cm-2 atm-1 at 296 K) of the 2nu3 band of 16O12C32S are determined from these linestrength measurements. Copyright 1997 Academic Press. Copyright 1997Academic Press

  12. Gold awards for CERN's top suppliers!

    CERN Multimedia

    2003-01-01

    CERN's awards to the LHC project's best suppliers are now into their second year. Three companies received 'Golden Hadrons' for 2003. The Golden Hadron awards were presented to the delighted representatives of the winning firms by LHC Project Leader Lyn Evans on Friday 16 May. Only three out of the LHC's four hundred suppliers were lucky enough to receive a gold award. The consortium IHI (Japan)-Linde Kryotechnik (Switzerland), the Belgian company JDL Technologies and the Japanese firm Furukawa Electric Company were rewarded not only for their technical and financial achievements but also for their compliance with contractual deadlines. The 2003 Golden Hadron winners with Lyn Evans. From left to right: Armin Senn, Thomas Voigt, Kirkor Kurtcuoglu of LINDE KRYOTECHNIK ; Tadaaki Honda, Project Leader and Motoki Yoshinaga, Associate Director of IHI Corporation ; Lyn Evans, LHC Project Leader; Shinichiro Meguro, Managing Director of FURUKAWA ELECTRIC COMPANY ; Nobuyoshi Saji, Consulting Engineer of IHI Corporatio...

  13. Electro-mechanical response of functionally graded beams with imperfectly integrated surface piezoelectric layers

    Institute of Scientific and Technical Information of China (English)

    YAN Wei; CHEN Weiqiu

    2006-01-01

    The time-dependent behavior of a simply-supported functionally graded beam bonded with piezoelectric sensors and actuators is studied using the state-space method. The creep behavior of bonding adhesives between piezoelectric layers and beam is characterized by a Kelvin-Voigt viscoelastic model, which is practical in a high temperature circumstance. Both the host elastic functionally graded beam and the piezoelectric layers are orthotropic and in a state of plane stress, with the former being inhomogeneous along the thickness direction. A laminate model is employed to approximate the host beam. Moreover, the coupling effect between the elastic deformation and electric field in piezoelectric layers is considered. Results indicate that the viscoelastic property of interfacial adhesives has a significant effect on the function of bonded actuators and sensors with time elapsing.

  14. Determination of the symmetries of an experimentally determined stiffness tensor; application to acoustic measurements

    CERN Document Server

    François, Marc Louis Maurice; Berthaud, Yves

    2009-01-01

    For most materials, the symmetry group is known a priori and deduced from the realization process. This allows many simplifications for the measurements of the stiffness tensor. We deal here with the case where the symmetry is a priori unknown, as for biological or geological materials, or when the process makes the material symmetry axis uncertain (some composites, monocrystals). The measurements are then more complicated and the raw stiffness tensor obtained does not exhibit any symmetry in the Voigt's matricial form, as it is expressed in the arbitrarily chosen specimen's base. A complete ultrasonic measurement of the stiffness tensor from redundant measurements is proposed. In a second time, we show how to make a plane symmetry pole figure able to give visual information about the quasi-symmetries of a raw stiffness tensor determined by any measurement method. Finally we introduce the concept of distance from a raw stiffness tensor to one of the eight symmetry classes available for a stiffness tensor. The...

  15. Effect of geometric size on mechanical properties of dielectric elastomers based on an improved visco-hyperelastic film model

    Science.gov (United States)

    Chang, Mengzhou; Wang, Zhenqing; Tong, Liyong; Liang, Wenyan

    2017-03-01

    Dielectric polymers show complex mechanical behaviors with different boundary conditions, geometry size and pre-stress. A viscoelastic model suitable for inhomogeneous deformation is presented integrating the Kelvin-Voigt model in a new form in this work. For different types of uniaxial tensile test loading along the length direction of sample, single-step-relaxation tests, loading–unloading tests and tensile–creep–relaxation tests the improved model provides a quite favorable comparison with the experiment results. Moreover, The mechanical properties of test sample with several length–width ratios under different boundary conditions are also invested. The influences of the different boundary conditions are calculated with a stress applied on the boundary point and the result show that the fixed boundary will increase the stress compare with homogeneous deformation. In modeling the effect of pre-stress in the shear test, three pre-stressed mode are discussed. The model validation on the general mechanical behavior shows excellent predictive capability.

  16. Equation of Diffusion of a Composite Mixture into a Composite Medium

    Science.gov (United States)

    Kravchuk, A. S.; Kravchuk, A. I.; Popova, T. S.

    2016-07-01

    The equation of diffusion of a composite mixture into a composite medium has been obtained for the first time. The assumption used is that the macropoint of the medium, i.e., an elementary macrovolume, in which the statistical parameters of distribution of inhomogeneities coincide with the corresponding values assigned for the medium as a whole, is small compared to the geometric dimensions of the volume considered. The ″Reuss-Voigt fork″ has been obtained for determining the limits of the change in the diffusion coefficient. Thereafter the fork is narrowed to the ″Kravchuk-Tarasyuk fork.″ Effective diffusion coefficients are obtained as an arithmetic mean value of the Kravchuk-Tarasyuk fork. The found averaged physical parameters can be used in solving specific physical problems for inhomogeneous media.

  17. Modeling of coherent ultrafast magneto-optical experiments: Light-induced molecular mean-field model

    Energy Technology Data Exchange (ETDEWEB)

    Hinschberger, Y. [Instituto de Física dos Materiais da Universidade do Porto, Departamento de Física et Astronomia, Rua do campo Alegre, 687, 4169-007 Porto (Portugal); Hervieux, P.-A. [Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504 BP 43 - F-67034 Strasbourg Cedex 2 (France)

    2015-12-28

    We present calculations which aim to describe coherent ultrafast magneto-optical effects observed in time-resolved pump-probe experiments. Our approach is based on a nonlinear semi-classical Drude-Voigt model and is used to interpret experiments performed on nickel ferromagnetic thin film. Within this framework, a phenomenological light-induced coherent molecular mean-field depending on the polarizations of the pump and probe pulses is proposed whose microscopic origin is related to a spin-orbit coupling involving the electron spins of the material sample and the electric field of the laser pulses. Theoretical predictions are compared to available experimental data. The model successfully reproduces the observed experimental trends and gives meaningful insight into the understanding of magneto-optical rotation behavior in the ultrafast regime. Theoretical predictions for further experimental studies are also proposed.

  18. Dynamic simulation of viscoelastic soft tissues in harmonic motion imaging application.

    Science.gov (United States)

    Shan, Baoxiang; Kogit, Megan L; Pelegri, Assimina A

    2008-10-20

    A finite element model was built to simulate the dynamic behavior of soft tissues subjected to sinusoidal excitation during harmonic motion imaging. In this study, soft tissues and tissue-like phantoms were modeled as isotropic, viscoelastic, and nearly incompressible media. A 3D incompressible mixed u-p element of eight nodes, S1P0, was developed to accurately calculate the stiffness matrix for soft tissues. The finite element equations of motion were solved using the Newmark method. The Voigt description for tissue viscosity was applied to estimate the relative viscous coefficient from the phase shift between the response and excitation in a harmonic case. After validating our model via ANSYS simulation and experiments, a MATLAB finite element program was then employed to explore the effect of excitation location, viscosity, and multiple frequencies on the dynamic displacement at the frequency of interest.

  19. Spin Flips versus Spin Transport in Nonthermal Electrons Excited by Ultrashort Optical Pulses in Transition Metals

    Science.gov (United States)

    Shokeen, V.; Sanchez Piaia, M.; Bigot, J.-Y.; Müller, T.; Elliott, P.; Dewhurst, J. K.; Sharma, S.; Gross, E. K. U.

    2017-09-01

    A joint theoretical and experimental investigation is performed to understand the underlying physics of laser-induced demagnetization in Ni and Co films with varying thicknesses excited by 10 fs optical pulses. Experimentally, the dynamics of spins is studied by determining the time-dependent amplitude of the Voigt vector, retrieved from a full set of magnetic and nonmagnetic quantities performed on both sides of films, with absolute time reference. Theoretically, ab initio calculations are performed using time-dependent density functional theory. Overall, we demonstrate that spin-orbit induced spin flips are the most significant contributors with superdiffusive spin transport, which assumes only that the transport of majority spins without spin flips induced by scattering does not apply in Ni. In Co it plays a significant role during the first ˜20 fs only. Our study highlights the material dependent nature of the demagnetization during the process of thermalization of nonequilibrium spins.

  20. Ab initio study of the structural stability, elastic, electronic and optical properties of NaMgHiFj [(i, j) = (3, 0), (2, 1), (1, 2), (0, 3)] compounds

    Science.gov (United States)

    Chihi, T.; Fatmi, M.; Ghebouli, B.

    2017-08-01

    We studied the structural, elastic, electronic and optical properties of the orthorhombic NaMgH3, NaMgH2F, NaMgHF2 and NaMgF3 compounds. By means of the self-consistent CASTEP code, pseudopotentials, density functional theory in the LDA and GGA approximations, basic physical properties, such as lattice constant, shear modulus, elastic constants (Cij) and optical constants are computed. This study includes elastic parameters of mono and poly-crystalline aggregates. Derived elastic constants, such as bulk, Young's and Shear modulus, Poisson coefficient, Debye temperature and brittle/ductile behavior are estimated with the polycrystalline approach, using Voigt-Reuss-Hill theory. The calculations show that the orthorhombic Pnma structures are mechanically and dynamically stable in the pressure range (0-20 GPa). The calculated density of states shows that the orthorhombic compounds are insulators.

  1. Structural stability, mechanical properties, electronic structures and thermal properties of XS (X = Ti, V, Cr, Mn, Fe, Co, Ni) binary compounds

    Science.gov (United States)

    Liu, Yangzhen; Xing, Jiandong; Fu, Hanguang; Li, Yefei; Sun, Liang; Lv, Zheng

    2017-08-01

    The properties of sulfides are important in the design of new iron-steel materials. In this study, first-principles calculations were used to estimate the structural stability, mechanical properties, electronic structures and thermal properties of XS (X = Ti, V, Cr, Mn, Fe, Co, Ni) binary compounds. The results reveal that these XS binary compounds are thermodynamically stable, because their formation enthalpy is negative. The elastic constants, Cij, and moduli (B, G, E) were investigated using stress-strain and Voigt-Reuss-Hill approximation, respectively. The sulfide anisotropy was discussed from an anisotropic index and three-dimensional surface contours. The electronic structures reveal that the bonding characteristics of the XS compounds are a mixture of metallic and covalent bonds. Using a quasi-harmonic Debye approximation, the heat capacity at constant pressure and constant volume was estimated. NiS possesses the largest CP and CV of the sulfides.

  2. STABILITY ANALYSIS OF VISCOELASTIC CURVED PIPES CONVEYING FLUID

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-min; ZHANG Zhan-wu; ZHAO Feng-qun

    2005-01-01

    Based on the Hamilton's principle for elastic systems of changing mass, a differential equation of motion for viscoelastic curved pipes conveying fluid was derived using variational method, and the complex characteristic equation for the viscoelastic circular pipe conveying fluid was obtained by normalized power series method. The effects of dimensionless delay time on the variation relationship between dimensionless complex frequency of the clamped-clamped viscoelastic circular pipe conveying fluid with the Kelvin-Voigt model and dimensionless flow velocity were analyzed. For greater dimensionless delay time, the behavior of the viscoelastic pipe is that the first, second and third mode does not couple, while the pipe behaves divergent instability in the first and second order mode, then single-mode flutter takes place in the first order mode.

  3. EPR and DNP Properties of Certain Novel Single Electron Contrast Agents Intended for Oximetric Imaging

    DEFF Research Database (Denmark)

    Ardenkjær-Larsen, J. H.; Laursen, I; Leunbach, I.;

    1998-01-01

    Parameters of relevance to oximetry with Overhauser magnetic resonance imaging (OMRI) have been measured for three single electron contrast agents of the triphenylmethyl type. The single electron contrast agents are stable and water soluble. Magnetic resonance properties of the agents have been...... examined with electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), and dynamic nuclear polarization (DNP) at 9.5 mT in water, isotonic saline, plasma, and blood at 23 and 37°C. The relaxivities of the agents are about 0.2–0.4 mM−1s−1and the DNP enhancements extrapolate close...... to the dipolar limit. The agents have a single, narrow EPR line, which is analyzed as a Voigt function. The linewidth is measured as a function of the agent concentration and the oxygen concentration. The concentration broadenings are about 1–3 μT/mM and the Lorentzian linewidths at infinite dilution are less...

  4. Bilinear Expansion For Redistribution Functions

    Science.gov (United States)

    Harutyunian, Haik; Alecian, Georges; Khachatryan, Knarik; Vardanyan, Ani

    2016-11-01

    We suggest here a method for construction of a bilinear expansion for an angle-averaged redistribution function. This function describes the elementary act of a photon scattering by a model two-level atom with the upper level broadened due to radiation damping. An eigenvalue and eigenvector determination problem is formulated and the relevant matrices are found analytically. Numerical procedures for their computations are elaborated as well. A simple method for the numerical calculations accuracy evaluation is suggested. It is shown that a family of redistribution functions describing the light scattering process within the spectral line frequencies can be constructed if the eigenvalue problem for the considered function is solved. It becomes possible if the eigenvalues and eigenvectors with the appropriate basic functions are used. The Voigt function and its derivatives used as basic functions are studied in detail as well.

  5. TRANSVERSAL INERTIAL EFFECT ON RELAXATION/RETARDATION TIME OF CEMENT MORTAR UNDER HARMONIC WAVE

    Institute of Scientific and Technical Information of China (English)

    Jue Zhu; Yonghui Cao; Jiankang Chen

    2008-01-01

    Under dynamic loading, the constitutive relation of the cement mortar will be signif-icantly affected by the transversal inertial effect of specimens with large diameters. In this paper,one-dimensional theoretical analysis is carried out to determine the transversal inertial effect on the relaxation/retardation time of the cement mortar under the harmonic wave. Relaxation time or retardation time is obtained by means of the wave velocity, attenuation coefficient and the frequency of the harmonic wave. Thus, the transversal inertial effect on the relaxation time from Maxwell model, as well as on retardation time from Voigt model is analyzed. The results show that the transversal inertial effect may lead to the increase of the relaxation time, but induce the decrease of the retardation time. Those should be taken into account when eliminating the transversal inertial effect in applications.

  6. Vibration analysis of viscoelastic single-walled carbon nanotubes resting on a viscoelastic foundation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Da Peng; Lei, Yong Jun; Shen, Zhi Bin [College of Aerospace Science and Engineering, National University of Defense Technology, Changsha (China); Wang, Cheng Yuan [Zienkiewicz Centre for Computational Engineering, College of Engineering, Swansea University, Swansea Wales (United Kingdom)

    2017-01-15

    Vibration responses were investigated for a viscoelastic Single-walled carbon nanotube (visco-SWCNT) resting on a viscoelastic foundation. Based on the nonlocal Euler-Bernoulli beam model, velocity-dependent external damping and Kelvin viscoelastic foundation model, the governing equations were derived. The Transfer function method (TFM) was then used to compute the natural frequencies for general boundary conditions and foundations. In particular, the exact analytical expressions of both complex natural frequencies and critical viscoelastic parameters were obtained for the Kelvin-Voigt visco-SWCNTs with full foundations and certain boundary conditions, and several physically intuitive special cases were discussed. Substantial nonlocal effects, the influence of geometric and physical parameters of the SWCNT and the viscoelastic foundation were observed for the natural frequencies of the supported SWCNTs. The study demonstrates the efficiency and robustness of the developed model for the vibration of the visco-SWCNT-viscoelastic foundation coupling system.

  7. Astrophysical Sources of Statistical Uncertainty in Precision Radial Velocities and Their Approximations

    CERN Document Server

    Beatty, Thomas G

    2015-01-01

    We investigate astrophysical contributions to the statistical uncertainty of precision radial velocity measurements of stellar spectra. We analytically determine the uncertainty in centroiding isolated spectral lines broadened by Gaussian, Lorentzian, Voigt, and rotational profiles, finding that for all cases and assuming weak lines, the uncertainty is the line centroid is $\\sigma_V\\approx C\\,\\Theta^{3/2}/(W I_0^{1/2})$, where $\\Theta$ is the full-width at half-maximum of the line, $W$ is the equivalent width, and $I_0$ is the continuum signal-to-noise ratio, with $C$ a constant of order unity that depends on the specific line profile. We use this result to motivate approximate analytic expressions to the total radial velocity uncertainty for a stellar spectrum with a given photon noise, resolution, wavelength, effective temperature, surface gravity, metallicity, macroturbulence, and stellar rotation. We use these relations to determine the dominant contributions to the statistical uncertainties in precision ...

  8. Creep of parylene-C film

    KAUST Repository

    Lin, Jeffrey Chun-Hui

    2011-06-01

    The glass transition temperature of as-deposited parylene-C is first measured to be 50°C with a ramping-temperature-dependent modulus experiment. The creep behavior of parylene-C film in the primary and secondary creep region is then investigated below and above this glass transition temperature using a dynamic mechanical analysis (DMA) machine Q800 from TA instruments at 8 different temperatures: 10, 25, 40, 60, 80, 100, 120 and 150°C. The Burger\\'s model, which is the combined Maxwell model and Kelvin-Voigt model, fits well with our primary and secondary creep data. Accordingly, the results show that there\\'s little or no creep below the glass transition temperature. Above the glass transition temperature, the primary creep and creep rate increases with the temperature, with a retardation time constant around 6 minutes. © 2011 IEEE.

  9. Magnetized Epsilon-Near-Zero (ENZ) Structures: Hall Opacity, Hall Transparency, and One-Way Photonic Surface States

    CERN Document Server

    Davoyan, Arthur

    2013-01-01

    We study propagation of transverse-magnetic (TM) electromagnetic waves in the bulk and at the surface of magnetized epsilon-near-zero (ENZ) medium in a Voigt configuration. We reveal that in a certain range of material parameters novel regimes of wave propagation emerge: we show that the transparency of the medium can be altered with the magnetization leading either to magnetically induced Hall opacity or Hall transparency of the ENZ. In our theoretical study, we demonstrate that surface waves at the interface between either a transparent or an opaque Hall medium and a homogeneous medium may, under certain conditions, be predominantly one-way. Moreover, we predict that one-way photonic surface states may exist at the interface of an opaque Hall ENZ and a regular metal, giving rise to a possibility for backscattering immune wave propagation and isolation.

  10. Pressure broadening and collisional narrowing in OH(v=1 <-- 0) rovibrational transitions with Ar, He, O2, and N2

    Science.gov (United States)

    Schiffman, A.; Nesbitt, David J.

    1994-02-01

    Line shapes are measured for OH(v=1←0) transitions in the presence of Ar, He, O2, and N2 as a function of N rotational, spin-orbit, and λ doublet states. Pressure broadening coefficients for all transitions and buffer gases are determined from fits of the observed line shapes to the Voigt profile. The dependencies of the observed broadening coefficients on the OH quantum levels are discussed and compared with previous pressure broadening studies in HF and NO. The observed OH line shapes are interpreted in terms of their impact on the determination of mesospheric and stratospheric OH populations, temperatures, and quantum state distributions from OH nightglow and dayglow emission. In the case of OH+Ar, evidence for Dicke narrowing is presented and narrowing coefficients are reported from fits to a ``hard collision'' model.

  11. Structural, elastic and electronic properties of C14-type Al2M (M=Mg, Ca, Sr and Ba) Laves phases

    Science.gov (United States)

    Lishi, Ma; Yonghua, Duan; Runyue, Li

    2017-02-01

    The structural and mechanical properties, Debye temperatures and anisotropic sound velocities of the Laves phases Al2M (M=Mg, Ca, Sr and Ba) with C14-type structure were investigated using the first-principles corresponding calculations. The corresponding calculated structural parameters and formation enthalpies are in good agreement with the available theoretical values, and Al2Ca has the best phase stability. The mechanical properties, including elastic constants, bulk modulus B, shear modulus G, Young's modulus E, and Poisson ratio ν, were deduced within the Voigt-Reuss-Hill approximation. The brittleness and ductility were estimated by the values of Poisson ratio, B/G and Cauchy pressure. Moreover, the elastic anisotropy was investigated by calculating and discussing several anisotropy indexes. Finally, the electronic structures were used to illustrate the bonding characteristics of C14-Al2M (M=Mg, Ca, Sr and Ba) phases.

  12. The elastic constants and anisotropy of superconducting MgCNi3 and CdCNi3 under different pressure

    KAUST Repository

    Feng, Huifang

    2013-11-23

    The second-order elastic constants (SOECs) and third-order elastic constants (TOECs) of MgCNi3 and CdCNi3 are presented by using first-principles methods combined with homogeneous deformation theory. The Voigt-Reuss-Hill (VRH) approximation are used to calculate the bulk modulus B, shear modulus G, averaged Young\\'s modulus E and Poisson\\'s ratio ν for polycrystals and these effective modulus are consistent with the experiments. The SOECs under different pressure of MgCNi3 and CdCNi3 are also obtained based on the TOECs. Furthermore, the Zener anisotropy factor, Chung-Buessem anisotropy index, and the universal anisotropy index are used to describe the anisotropy of MgCNi3 and CdCNi3. The anisotropy of Young\\'s modulus of single-crystal under different pressure is also presented. © 2013 Springer Science+Business Media New York.

  13. Predicting the Coupling Properties of Axially-Textured Materials

    Directory of Open Access Journals (Sweden)

    María E. Fuentes-Montero

    2013-10-01

    Full Text Available A description of methods and computer programs for the prediction of “coupling properties” in axially-textured polycrystals is presented. Starting data are the single-crystal properties, texture and stereography. The validity and proper protocols for applying the Voigt, Reuss and Hill approximations to estimate coupling properties effective values is analyzed. Working algorithms for predicting mentioned averages are given. Bunge’s symmetrized spherical harmonics expansion of orientation distribution functions, inverse pole figures and (single and polycrystals physical properties is applied in all stages of the proposed methodology. The established mathematical route has been systematized in a working computer program. The discussion of piezoelectricity in a representative textured ferro-piezoelectric ceramic illustrates the application of the proposed methodology. Polycrystal coupling properties, predicted by the suggested route, are fairly close to experimentally measured ones.

  14. Optical and magneto-optical properties of metal phthalocyanine and metal porphyrin thin films.

    Science.gov (United States)

    Birnbaum, Tobias; Hahn, Torsten; Martin, Claudia; Kortus, Jens; Fronk, Michael; Lungwitz, Frank; Zahn, Dietrich R T; Salvan, Georgeta

    2014-03-12

    The optical constants together with the magneto-optical Voigt constants of several phthalocyanine (Pc) and methoxy functionalized tetraphenylporphyrin (TMPP) thin films prepared on silicon substrates are presented. The materials investigated are MePc with Me = Fe, Co, Ni, Cu, Zn and MeTMPP with Me = Cu, Ni. We also compared our results to the metal-free H2Pc, H2TPP and H2TMPP. The experimental results will be supported by electronic structure calculations based on density functional theory (DFT) and interpreted using the perimeter model initially proposed by Platt. The model allows for qualitative understanding of the forbidden character of transitions in planar, aromatic molecules, and is able to qualify differences between Pc and TMPP type materials.

  15. Analysis of oscillation processes in a blocky medium by means of continuous models

    Science.gov (United States)

    Sadovskii, V. M.; Chentsov, E. P.

    2016-10-01

    Analysis of oscillation processes in a blocky medium is fulfilled using models, wherein elastic blocks interact via inter-layers with different mechanical properties. To describe wave processes, three different models are applied. First model considers elastic interaction between blocks; second one is the viscoelastic Pointing-Thomson model, that combines both Maxwell and Kelvin-Voigt models, and third one, named as the model with a rigid contact, excludes a possibility of blocks interpenetration. The dissipationless Ivanov scheme is applied in interlayers, while in blocks the Godunov gap decay scheme is used. It is shown that additional enclosing equations, which guarantee absence of energy dissipation in the Ivanov scheme, provide thermodynamic consistency of the model, meaning that the difference analogue of the energy conservation law for blocky structures is performed. Using the MPI technology, a parallel software is designed for simulation of the elastic waves propagation in a two-dimensional blocky medium.

  16. Absorption line profile recovery based on TDLS and MEMS micro-mirror for photoacoustic gas sensing.

    Science.gov (United States)

    Li, Li; Arsad, Norhana; Stewart, George; Thursby, Graham; Uttamchandani, Deepak; Culshaw, Brian; Yi-ding, Wang

    2011-07-01

    A novel and efficient absorption line recovery technique is presented. A micro-electromechanical systems (MEMS) mirror driven by an electrothermal actuator is used to generate laser intensity modulation through the mirror reflection. Tunable diode laser spectroscopy (TDLS) and photoacoustic spectroscopy (PAS) are used to recover the target absorption line profile which is compared with the theoretical Voigt profile. The target gas is 0.01% acetylene (C2H2) in a nitrogen host gas. The laser diode wavelength is swept across the P17 absorption line of acetylene at 1535.4 nm by a current ramp, and an erbium-doped fibre amplifier (EDFA) is used to enhance the optical intensity and increase the signal-to-noise ratio (SNR). A SNR of about 35 is obtained with 100 mW laser power from the EDFA. Good agreement is achieved between the experimental results and the theoretical simulation for the P17 absorption line profile.

  17. Thermal effect on the dynamic response of axially functionally graded beam subjected to a moving harmonic load

    Science.gov (United States)

    Wang, Yuewu; Wu, Dafang

    2016-10-01

    Dynamic response of an axially functionally graded (AFG) beam under thermal environment subjected to a moving harmonic load is investigated within the frameworks of classical beam theory (CBT) and Timoshenko beam theory (TBT). The Lagrange method is employed to derive the equations of thermal buckling for AFG beam, and then with the critical buckling temperature as a parameter the Newmark-β method is adopted to evaluate the dynamic response of AFG beam under thermal environments. Admissible functions denoting transverse displacement are expressed in simple algebraic polynomial forms. Temperature-dependency of material constituent is considered. The rule of mixture (Voigt model) and Mori-Tanaka (MT) scheme are used to evaluate the beam's effective material properties. A ceramic-metal AFG beam with immovable boundary condition is considered as numerical illustration to show the thermal effects on the dynamic behaviors of the beam subjected to a moving harmonic load.

  18. Non-reciprocal directional dichroism in the AFM phase of BiFeO3 at THz frequencies

    Science.gov (United States)

    Nagel, Urmas; Rõõm, T.; Farkas, D.; Szaller, D.; Bordács, S.; Kézsmárki, I.; Engelkamp, H.; Ozaki, Y.; Tomiaki, Y.; Ito, T.; Fishman, Randy S.

    We did THz absorption spectroscopy of BiFeO3 single crystals in the AFM phase, where the spin cycloid is destroyed in magnetic fields between 18 T and 32 T in Voigt geometry at 1.6 K. If B0 ∥ [ 1 1 0 ] , we see strong directional dichroism (DD) of absorption of the magnon mode with light propagating along the direction of the ferroelectric polarization k ∥ P ∥ [ 111 ] and eω ∥ [ 1 1 0 ] , bω ∥ [ 1 1 2 ] . The sign of DD can be reversed (i) by reversing the direction of B0 or (ii) by flipping the sample, thus reversing the propagation direction of light. The observed effect is caused by the strong magneto-electric coupling in the collinear AFM phase. Research sponsored by the Estonian Ministry of Education and Research (IUT23-3).

  19. Structural, elastic and electronic properties of C14-type Al{sub 2}M (M=Mg, Ca, Sr and Ba) Laves phases

    Energy Technology Data Exchange (ETDEWEB)

    Lishi, Ma; Yonghua, Duan, E-mail: duanyh@kmust.edu.cn; Runyue, Li

    2017-02-15

    The structural and mechanical properties, Debye temperatures and anisotropic sound velocities of the Laves phases Al{sub 2}M (M=Mg, Ca, Sr and Ba) with C14-type structure were investigated using the first-principles corresponding calculations. The corresponding calculated structural parameters and formation enthalpies are in good agreement with the available theoretical values, and Al{sub 2}Ca has the best phase stability. The mechanical properties, including elastic constants, bulk modulus B, shear modulus G, Young’s modulus E, and Poisson ratio ν, were deduced within the Voigt-Reuss-Hill approximation. The brittleness and ductility were estimated by the values of Poisson ratio, B/G and Cauchy pressure. Moreover, the elastic anisotropy was investigated by calculating and discussing several anisotropy indexes. Finally, the electronic structures were used to illustrate the bonding characteristics of C14-Al{sub 2}M (M=Mg, Ca, Sr and Ba) phases.

  20. Absorption Line Profile Recovery Based on TDLS and MEMS Micro-Mirror for Photoacoustic Gas Sensing

    Institute of Scientific and Technical Information of China (English)

    LI Li; Norhana Arsad; George Stewart; Graham Thursby; Deepak Uttamchandani; Brian Culshaw; WANG Yi-ding

    2011-01-01

    A novel and efficient absorption line recovery technique is presented. A micro-electromechanical systems (MEMS) mirror driven by an electrothermal actuator is used to generate laser intensity modulation through the mirror reflection. Tunable diode laser spectroscopy (TDLS) and photoacoustic spectroscopy (PAS) are used to recover the target absorption line profile which is compared with the theoretical Voigt profile. The target gas is 0.01% acetylene (C2 H2 ) in a nitrogen host gas. The laser diode wavelength is swept across the P17 absorption line of acetylene at 1 535.4 nm by a current ramp, and an erbium-doped fibre amplifier (EDFA) is used to enhance the optical intensity and increase the signal-to-noise ratio (SNR). A SNR of about 35 is obtained with 100 mW laser power from the EDFA Good agreement is achieved between the experimental results and the theoretical simulation for the P17 absorption line profile.

  1. Polaritons dispersion in a composite ferrite-semiconductor structure near gyrotropic-nihility state

    CERN Document Server

    Tuz, Vladimir R

    2015-01-01

    The dispersion law of both bulk and surface polaritons in a finely-stratified ferrite-semiconductor structure which is under an action of an external static magnetic field in the Voigt geometry is derived and examined in details. In the long-wavelength limit, when the thicknesses of the structure's layers as well as its period are optically thin, with an assistance of the method of effective anisotropic homogeneous medium, the expressions for relative effective constitutive parameters are retrieved in a general tensor form. The gyrotropic-nihility state is defined from the dispersion equation related to the bulk polaritons as a particular extreme condition, at which the longitudinal component of the corresponding constitutive tensor, as well as the corresponding bulk constant simultaneously acquire zero. The extraordinary spectral features of both bulk and surface polaritons near the frequency of the gyrotropic-nihility state are elucidated.

  2. The adhesion and hysteresis effect in friction skin with artificial materials

    Science.gov (United States)

    Subhi, K. A.; Tudor, A.; Hussein, E. K.; Wahad, H. S.

    2017-02-01

    Human skin is a soft biomaterial with a complex anatomical structure and it has a complex material behavior during the mechanical contact with objects and surfaces. The friction adhesion component is defined by means of the theories of Johnson-Kendall-Roberts (JKR), Derjaguin-Muller-Toporov (DMT) and Maugis – Dugdale (MD). We shall consider the human skin entering into contact with a rigid surface. The deformation (hysteresis) component of the skin friction is evaluated with Voigt rheological model for the spherical contact, with the original model, developed in MATHCAD software. The adhesive component of the skin friction is greater than the hysteresis component for all friction parameters (load, velocity, the strength of interface between skin and the artificial material).

  3. Wave propagation in fluid-conveying viscoelastic single-walled carbon nanotubes with surface and nonlocal effects

    Science.gov (United States)

    Zhen, Ya-Xin

    2017-02-01

    In this paper, the transverse wave propagation in fluid-conveying viscoelastic single-walled carbon nanotubes is investigated based on nonlocal elasticity theory with consideration of surface effect. The governing equation is formulated utilizing nonlocal Euler-Bernoulli beam theory and Kelvin-Voigt model. Explicit wave dispersion relation is developed and wave phase velocities and frequencies are obtained. The effect of the fluid flow velocity, structural damping, surface effect, small scale effects and tube diameter on the wave propagation properties are discussed with different wave numbers. The wave frequency increases with the increase of fluid flow velocity, but decreases with the increases of tube diameter and wave number. The effect of surface elasticity and residual surface tension is more significant for small wave number and tube diameter. For larger values of wave number and nonlocal parameters, the real part of frequency ratio raises.

  4. SMEs, Competition and Entry - A developing country perspective

    DEFF Research Database (Denmark)

    Jensen, Camilla

    with a sizeable informal sector in developing countries and corruption. Other leading transition researchers such as Andrei Shleifer offer a variety of views on the informal sector from the romantic to the parasitic. This paper leans on the realist interpretation of de Soto grounded in institutional theory. High...... entry barriers push the entrepreneurs towards the informal sector. Whether entrepreneurs succeed in the transition towards the formal sector depends on the size of the entry barriers which are indirectly regulated both by informal institutions such as corruption and formal institutions...... such as competition policy. The model is tested using the World Bank's BEEPS dataset which is a repeated cross section survey of firms across countries in development and transition. This data gives access to observe among other firm size and whether firms pay a bribe or not. This data is combined with Stephan Voigt...

  5. Low-redshift evolution of the Lyman $\\alpha$ Forest

    CERN Document Server

    Theuns, T; Efstathiou, G P

    1998-01-01

    The low-redshift evolution of the intergalactic medium is investigated using hydrodynamic cosmological simulations. The assumed cosmological model is a critical density cold dark matter universe. The imposed uniform background of ionizing radiation has the amplitude, shape and redshift evolution as computed from the observed quasar luminosity function by Haardt & Madau. We have analysed simulated Lyman-alpha spectra using Voigt-profile fitting, mimicking the procedure with which quasar spectra are analysed. Our simulations reproduce the observed evolution of the number of Lyman-alpha absorption lines over the whole observed interval of z=0.5 to z=4. In particular, our simulations show that the decrease in the rate of evolution of Lyman-alpha absorption lines at z< 2, as observed by Hubble Space Telescope, can be explained by the steep decline in the photo-ionizing background resulting from the rapid decline in quasar numbers at low redshift.

  6. Ab initio-based fracture toughness estimates and transgranular traction-separation modelling of zirconium hydrides

    Science.gov (United States)

    Olsson, P. A. T.; Kese, K.; Kroon, M.; Alvarez Holston, A.-M.

    2015-06-01

    In this work we report the results of an ab initio study of the transgranular fracture toughness and cleavage of brittle zirconium hydrides. We use the Griffith-Irwin relation to assess the fracture toughness using calculated surface energy and estimated isotropic Voigt-Reuss-Hill averages of the elastic constants. The calculated fracture toughness values are found to concur well with experimental data, which implies that fracture is dominated by cleavage failure. To investigate the cleavage energetics, we model the decohesion process. To describe the interplanar interaction we adopt Rose’s universal binding energy relation, which is found to reproduce the behaviour accurately. The modelling shows that the work of fracture and ductility decreases with increasing hydrogen content.

  7. Compressive behavior and energy absorption of metal porous polymer composite with interpenetrating network structure

    Institute of Scientific and Technical Information of China (English)

    LIU Yu; GONG Xiao-lu

    2006-01-01

    Interpenetrating phase composites (IPCs) are a new class of composite materials with improved combinations of mechanical and physical properties. This study was performed on a new type of IPC called metal porous polymer composite (MPPC) with an interpenetrating network structure. Aluminum-polypropylene (Al-PE) and Aluminum-epoxy resin (Al-Ep) composites were produced by infiltrating the polymer in the aluminum foam. The composite microstructures were characterized using SEM observation. The compressive behavior and energy absorption characteristics of MPPC were investigated and compared with the aluminum foams. The compressive modulus of composite was compared with the VOIGT-REUSS bounds and HASHIN-SHTRIKMAN (H-S) bounds models. The experimental modulus of compressive tests falls well within the theoretical models.

  8. Frequency-comb-assisted precision laser spectroscopy of CHF{sub 3} around 8.6 μm

    Energy Technology Data Exchange (ETDEWEB)

    Gambetta, Alessio; Coluccelli, Nicola; Cassinerio, Marco; Fernandez, Toney Teddy; Gatti, Davide; Laporta, Paolo; Galzerano, Gianluca, E-mail: gianluca.galzerano@polimi.it [Dipartimento di Fisica - Politecnico di Milano and Istituto di Fotonica e Nanotecnologie - CNR, Piazza Leonardo da Vinci 32, 20133 Milano (Italy); Castrillo, Antonio; Fasci, Eugenio; Gianfrani, Livio [Dipartimento di Matematica e Fisica - Seconda Università di Napoli, Viale Lincoln 5, 81100 Caserta (Italy); Ceausu-Velcescu, Adina [Laboratoire de Mathématiques et Physique, Université de Perpignan, Via Domitia EA 4217, F-66860 Perpignan (France); Santamaria, Luigi; Di Sarno, Valentina [CNR-INO, Istituto Nazionale di Ottica, Via Campi Flegrei 34, 80078 Pozzuoli, NA (Italy); Maddaloni, Pasquale [CNR-INO, Istituto Nazionale di Ottica, Via Campi Flegrei 34, 80078 Pozzuoli, NA (Italy); INFN, Istituto Nazionale di Fisica Nucleare, Sez. Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, FI (Italy); De Natale, Paolo [INFN, Istituto Nazionale di Fisica Nucleare, Sez. Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, FI (Italy); CNR-INO, Istituto Nazionale di Ottica, Largo E. Fermi 6, 50125 Firenze (Italy)

    2015-12-21

    We report a high-precision spectroscopic study of room-temperature trifluoromethane around 8.6 μm, using a CW quantum cascade laser phase-locked to a mid-infrared optical frequency comb. This latter is generated by a nonlinear down-conversion process starting from a dual-branch Er:fiber laser and is stabilized against a GPS-disciplined rubidium clock. By tuning the comb repetition frequency, several transitions falling in the υ{sub 5} vibrational band are recorded with a frequency resolution of 20 kHz. Due to the very dense spectra, a special multiple-line fitting code, involving a Voigt profile, is developed for data analysis. The combination of the adopted experimental approach and survey procedure leads to fractional accuracy levels in the determination of line center frequencies, down to 2 × 10{sup −10}. Line intensity factors, pressure broadening, and shifting parameters are also provided.

  9. Focus: Simon Steen-Andersen

    DEFF Research Database (Denmark)

    2013), the prize for the best orchestral work at the recently held Doneueschinger Musiktage and The Nordic Council Music Prize in 2014. Seismograf/DMT wishes to celebrate the composer Simon Steen-Andersen. We present and reflect on parts of his comprehensive career, in a Danish and an international...... Rasmus Holmboe; a reflection on the importance of the unrepeatable in Steen-Andersen’s music by composer and PhD Rune Søchting, and a contextualisation of central works by Norwegian editor and writer Ida Habbestad. Our Swedish colleague Andreas Engström writes about the new piano concerto (english....... Watch the trailer. The idea for this Focus comes from Jens Voigt-Lund. It has been realised and edited by Sanne Krogh Groth and Rasmus Holmboe, and published with financial support from Carl Nielsen Fonden. English translations by Helen Clara Hemsley. The Focus is also published in a Danish version....

  10. Broadening of CO2 lines in the 4.3 μm region by H2O

    Science.gov (United States)

    Delahaye, T.; Landsheere, X.; Pangui, E.; Huet, F.; Hartmann, J.-M.; Tran, H.

    2016-08-01

    Transmission spectra of CO2 highly diluted in water vapor have been recorded at 50 and 95 °C for four pressures between 0.02 and 0.1 atm using a high resolution Fourier Transform spectrometer. The collisional (Lorentz) widths of many lines of the ν3 band (and of some of the ν3 + ν2 - ν2 hot band) have been retrieved from each spectrum through fits using Voigt line shapes. Our result are about 4% lower than the values recommended in a previous study but they confirm the relative variations of the line broadening on the rotational quantum numbers. We also provide the first determination of H2O-induced line shifts of CO2 lines.

  11. Goos-Hänchen Lateral Displacements at the Interface between Isotropic and Gyroelectric Media

    Directory of Open Access Journals (Sweden)

    Jinbao Wang

    2013-01-01

    Full Text Available A detailed study on Goos-Hänchen (GH lateral displacements of the reflected and transmitted waves propagating at the interface between an isotropic medium and a gyroelectric medium in Voigt configuration is presented. After the reflection coefficient and transmission coefficient are derived, based on the stationary phase approach, GH lateral displacements are obtained analytically. The numerical results for a specific gyroelectric medium are also given. It shows that with the existence of an applied magnetic field, the GH effect occurs not only during total reflection but also during nontotal reflection, which is not true for isotropic media. Moreover, due to the nonreciprocal property of the gyroelectric medium, the sign of the incident angle also influences the displacements. Finite-element method simulations have verified the theoretical results.

  12. A comparison of delayed self-heterodyne interference measurement of laser linewidth using Mach-Zehnder and Michelson interferometers.

    Science.gov (United States)

    Canagasabey, Albert; Michie, Andrew; Canning, John; Holdsworth, John; Fleming, Simon; Wang, Hsiao-Chuan; Aslund, Mattias L

    2011-01-01

    Linewidth measurements of a distributed feedback (DFB) fibre laser are made using delayed self heterodyne interferometry (DHSI) with both Mach-Zehnder and Michelson interferometer configurations. Voigt fitting is used to extract and compare the Lorentzian and Gaussian linewidths and associated sources of noise. The respective measurements are w(L) (MZI) = (1.6 ± 0.2) kHz and w(L) (MI) = (1.4 ± 0.1) kHz. The Michelson with Faraday rotator mirrors gives a slightly narrower linewidth with significantly reduced error. This is explained by the unscrambling of polarisation drift using the Faraday rotator mirrors, confirmed by comparing with non-rotating standard gold coated fibre end mirrors.

  13. Indication of worn WC/C surface locations of a dry-running twin-screw rotor by the oxygen incorporation in tungsten-related Raman modes

    Science.gov (United States)

    Debus, J.; Schindler, J. J.; Waldkirch, P.; Goeke, S.; Brümmer, A.; Biermann, D.; Bayer, M.

    2016-10-01

    By comparing the worn and untouched locations of a tungsten-carbide/carbon surface of a dry-running twin-screw rotor, we demonstrate that tungsten-oxide Raman modes become observable only at worn locations and the integral intensity of the Raman line at 680 cm-1, which is related to the incipient oxidation of the tungsten-carbide stretching mode, is enhanced. Its frequency and width moreover change significantly, thus indicating the mechanical distortion of the bonding that has been occurred during the wearing process. The shape of the tungsten-oxide Raman lines, resembling the Voigt function, hints at a surface morphology that is a characteristic for an amorphous solid environment. Our Raman scattering results may be exploited to characterize the degree of wear of coated surfaces and to identify signatures of a tribological layer.

  14. Development of a high dynamic range spectroscopic system for observation of neutral hydrogen atom density distribution in Large Helical Device core plasma

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, K., E-mail: fujii@me.kyoto-u.ac.jp; Atsumi, S.; Watanabe, S.; Shikama, T.; Hasuo, M. [Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Kyoto 606-8540 (Japan); Goto, M.; Morita, S. [National Institute for Fusion Science, Toki 509-5292 (Japan)

    2014-02-15

    We report development of a high dynamic range spectroscopic system comprising a spectrometer with 30% throughput and a camera with a low-noise fast-readout complementary metal-oxide semiconductor sensor. The system achieves a 10{sup 6} dynamic range (∼20 bit resolution) and an instrumental function approximated by a Voigt profile with Gauss and Lorentz widths of 31 and 0.31 pm, respectively, for 656 nm light. The application of the system for line profile observations of the Balmer-α emissions from high temperature plasmas generated in the Large Helical Device is also presented. In the observed line profiles, emissions are detected in far wings more than 1.0 nm away from the line center, equivalent to neutral hydrogen atom kinetic energies above 1 keV. We evaluate atom density distributions in the core plasma by analyzing the line profiles.

  15. Pressure-dependent water absorption cross sections for exoplanets and other atmospheres

    CERN Document Server

    Barton, Emma J; Yurchenko, Sergei N; Tennyson, Jonathan; Dudaryonok, Anna S; Lavrentieva, Nina N

    2016-01-01

    Many atmospheres (cool stars, brown dwarfs, giant planets, extrasolar planets) are predominately composed of molecular hydrogen and helium. H$_2{}^{16}$O is one of the best measured molecules in extrasolar planetary atmospheres to date and a major compound in the atmospheres of brown-dwarfs and oxygen-rich cool stars, yet the scope of experimental and theoretical studies on the pressure broadening of water vapour lines by collision with hydrogen and helium remains limited. Theoretical H$_2$- and He-broadening parameters of water vapour lines (rotational quantum number $J$ up to 50) are obtained for temperatures in the range 300 - 2000 K. Two approaches for calculation of line widths were used: (i) the averaged energy difference method and (ii) the empirical expression for $J$\\p $J$\\pp-dependence. Voigt profiles based on these widths and the BT2 line list are used to generate high resolution ($\\Delta \\tilde{\

  16. Characterization of barium titanate powder doped with sodium and potassium ions by using Rietveld refining; Caracterizacao do po de titanato de bario dopado com ions sodio e potasio com o refinamento de Rietveld

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, M.C.; Assis, J.T.; Pereira, F.R., E-mail: mcalixto@iprj.uerj.b [Universidade do Estado do Rio de Janeiro (IPRJ/UERJ), Nova Friburgo, RJ (Brazil). Instituto Politecnico; Araujo, J.C. [Universidade do Estado do Rio de Janeiro (FFP/UERJ), Sao Goncalo, RJ (Brazil). Fac. de Formacao de Professores; Moreira, E.L.; Moraes, V.C.A.; Lopes, A.R. [Centro Brasileiro de Pesquisas Fisicas (CBPF/MCT), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    A solid-reaction synthesis of doped barium titanate was done by employing barium carbonates, sodium, potassium and titanium oxides with classic procedures. Rietveld refining of X ray diffraction data of perovskite samples with tetragonal symmetry was applying and show good agreement. Besides, the treatment performed from 600 deg C produces nanocrystals of barium titanate with average size of 33 nm. The presence of endothermic peaks related to BaTiO{sub 3} formation at relatively low temperatures was determined by thermal analysis. A pseudo-Voigt Thompson-Cox-Hastings function was used to fit the standard samples of barium titanate. The Rietveld method has showed be efficient to detect the influences of temperature and doping on barium titanate microstructures. (author)

  17. X-ray elastic constants and residual stress of textured titanium nitride coating

    Energy Technology Data Exchange (ETDEWEB)

    Sue, J.A. (Union Carbide Coatings Service Corp., Indianapolis, IN (United States))

    1992-11-16

    X-ray elastic constants for the (422) and (333)/(511) reflections of the [l brace]111[r brace] textured TiN coating were determined. The coating exhibited high elastic anisotropy. The X-ray elastic constant of the (422) reflection was comparable with those predicted from single crystal elastic compliances on the basis of the Voigt and Reuss models, whereas a significant deviation from these models was found for (333)/(511). The residual stress of the coating was determined by X-ray diffraction and bi-metal deflection techniques. The magnitude of residual stress in the coating calculated using the measured X-ray elastic constants was in good agreement with these two reflections and, within experimental scatter, the values were also consistent with those obtained from the deflection measurement.

  18. Determination of foreign broadening coefficients for Methane Lines Targeted by the Tunable Laser Spectrometer (TLS) on the Mars Curiosity Rover

    Science.gov (United States)

    Manne, Jagadeeshwari; Bui, Thinh Q.; Webster, Christopher R.

    2017-04-01

    Molecular line parameters of foreign- broadening by air, carbon dioxide, and helium gas have been experimentally determined for infrared ro-vibrational spectral lines of methane isotopologues (12CH4 and 13CH4) at 3057 cm-1 targeted by the Tunable Laser Spectrometer (TLS) in the Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) Curiosity rover. From multi-spectrum analyses with the speed-dependent Voigt line profile with Rosenkrantz line-mixing, speed-dependence and line-mixing effects were quantified for methane spectra at total pressures up to 200 mbar. The fitted air-broadening coefficients deviated from 8-25% to those reported in the HITRAN-2012 database.

  19. The Method of Single Peak Fourier Analysis of Measuring the Size of Mosaic Block and Microstrain by X-ray Diffraction

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The values of mosaic block size and microstrain measured by the method of Voigt function are sometimes largely erroneous and difficult to be revised. In this paper, the causes of the “hook effect” which inevitably exists in the method of Fourier analysis are explained; then the method for resolving this effect is put forward; and finally the method of hypothetical function is used to simplify the method of the Fourier analysis from multi-peak to single-peak. By introducing the parameter m, this method can not only indicate the degree of errors, but also revise them as well. It is simple, clear and able to accomplish the intricate pattern calculation quickly by the aid of computer. In the end, we argue the identity between method of the approximate function and the Fourier analysis, and give a more accurate proportional coefficient k.

  20. Bounds and self-consistent estimates of the elastic constants of polycrystals

    Science.gov (United States)

    Kube, Christopher M.; Arguelles, Andrea P.

    2016-10-01

    The Hashin-Shtrikman bounds on the elastic constants have been previously calculated for polycrystalline materials with crystallites having general elastic symmetry (triclinic crystallite symmetry). However, the calculation of tighter bounds and the self-consistent estimates of these elastic constants has remained unsolved. In this paper, a general theoretical expression for the self-consistent elastic constants is formulated. An iterative method is used to solve the expression for the self-consistent estimates. Each iteration of the solution gives the next tighter set of bounds including the well-known Voigt-Reuss and Hashin-Shtrikman bounds. Thus, all of the bounds on the elastic constants and the self-consistent estimates for any crystallite symmetry are obtained in a single, computationally efficient procedure. The bounds and self-consistent elastic constants are reported for several geophysical materials having crystallites of monoclinic and triclinic symmetries.

  1. CERT TST December 2015 Visit Summary

    Energy Technology Data Exchange (ETDEWEB)

    Little, Robert Currier [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bailey, Teresa S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gamblin, G. Todd [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Olinger, Chad Tracy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pautz, Shawn D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Williams, Alan B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-25

    The annual PSAAP II TST visit to Texas A&M’s CERT Center was held on December 1-3, 2015. The agenda for the visit is attached. Non-TAMU attendees were: TST Members – Teresa Bailey (LLNL), Todd Gamblin (LLNL), Bob Little (LANL) – Chair, Chad Olinger (LANL), Shawn Pautz (SNL), Alan Williams (SNL);Other Lab staff – Skip Kahler (LANL), Ana Kupresanin (LLNL), and Rob Lowrie (LANL); AST Members – Nelson Hoffman (LANL) and Bob Voigt (Leidos) The TST wishes to express our appreciation to all involved with CERT for the high-quality posters and presentations and for the attention to logistics that enabled a successful visit. We have broken our comments into four sections: (1) Kudos, (2) Recommendations, (3) Feedback on Priorities for April Review, and (4) Follow-Up Activities with Labs.

  2. Tissue elasticity properties as biomarkers for prostate cancer.

    Science.gov (United States)

    Hoyt, Kenneth; Castaneda, Benjamin; Zhang, Man; Nigwekar, Priya; di Sant'agnese, P Anthony; Joseph, Jean V; Strang, John; Rubens, Deborah J; Parker, Kevin J

    2008-01-01

    In this paper we evaluate tissue elasticity as a longstanding but qualitative biomarker for prostate cancer and sonoelastography as an emerging imaging tool for providing qualitative and quantitative measurements of prostate tissue stiffness. A Kelvin-Voigt Fractional Derivative (KVFD) viscoelastic model was used to characterize mechanical stress relaxation data measured from human prostate tissue samples. Mechanical testing results revealed that the viscosity parameter for cancerous prostate tissue is greater than that derived from normal tissue by a factor of approximately 2.4. It was also determined that a significant difference exists between normal and cancerous prostate tissue stiffness (p cancer detection in prostate and may prove to be an effective adjunct imaging technique for biopsy guidance. Elasticity images obtained with quantitative sonoelastography agree with mechanical testing and histological results. Overall, results indicate tissue elasticity is a promising biomarker for prostate cancer.

  3. La teoría de la relatividad: ayer y hoy

    Directory of Open Access Journals (Sweden)

    Jorge L. Cervantes-Cota

    2006-01-01

    Full Text Available Explicamos los dos postulados dela teoría de la relatividad especial, poniendo énfasis en los conocimientos científicos históricos detrás de las ideas que empleó el joven Albert Einstein en 1905. El papel de científicos como Maxwell, Michelson, Voigt, Lorentz, Fitzgerald, entre otros, es dilucidado. También explicamos la geometría del nuevo espacio-tiempo que emana de la teoría, así como las consecuencias en la medición del espacio, tiempo y masas de observadores en movimiento relativo. Finalmente, se describen algunas de las aplicaciones que ha tenido y tiene una de las teorías más sencillas y probadas de la historia de la ciencia: la relatividad especial.

  4. Boundary element modeling of nondissipative and dissipative waves

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Genmeng [Univ. of Houston, TX (United States). Allied Geophysical Labs.; Zhou, Huawei [Univ. of Houston, TX (United States). Dept. of Geosciences

    1994-01-01

    A boundary element (BE) algorithm is developed to compute acoustic or SH-waves in models consisting of limited or unlimited volumes and irregular interfaces. The authors solve the BE system in the frequency domain so that anelasticity can be easily represented by different viscoelastic models, such as the Kelvin-Voigt type. Three illustrative computations are shown. The waveform given by the BE method for a circular inclusion model agrees well with that given by the finite-difference (FD) method. Dissipation of waves at high frequency caused by the presence of multi-cracks in an elastic medium resembles the masking effect of anelasticity. The waveforms for nondissipative and dissipative models containing hexagonal inclusions illustrate some interesting characteristics of the composite media.

  5. A Comparison of Delayed Self-Heterodyne Interference Measurement of Laser Linewidth Using Mach-Zehnder and Michelson Interferometers

    Directory of Open Access Journals (Sweden)

    Simon Fleming

    2011-09-01

    Full Text Available Linewidth measurements of a distributed feedback (DFB fibre laser are made using delayed self heterodyne interferometry (DHSI with both Mach-Zehnder and Michelson interferometer configurations. Voigt fitting is used to extract and compare the Lorentzian and Gaussian linewidths and associated sources of noise. The respective measurements are wL (MZI = (1.6 ± 0.2 kHz and wL (MI = (1.4 ± 0.1 kHz. The Michelson with Faraday rotator mirrors gives a slightly narrower linewidth with significantly reduced error. This is explained by the unscrambling of polarisation drift using the Faraday rotator mirrors, confirmed by comparing with non-rotating standard gold coated fibre end mirrors.

  6. Extended pump-probe Faraday rotation spectroscopy of the submicrosecond electron spin dynamics in n -type GaAs

    Science.gov (United States)

    Belykh, V. V.; Evers, E.; Yakovlev, D. R.; Fobbe, F.; Greilich, A.; Bayer, M.

    2016-12-01

    We develop an extended pump-probe Faraday rotation technique to study submicrosecond electron spin dynamics with picosecond time resolution in a wide range of magnetic fields. The electron spin dephasing time T2* and the longitudinal spin relaxation time T1, both approaching 250 ns in weak fields, are measured thereby in n -type bulk GaAs. By tailoring the pump pulse train through increasing the contained number of pulses, the buildup of resonant spin amplification is demonstrated for the electron spin polarization. The spin precession amplitude in high magnetic fields applied in the Voigt geometry shows a nonmonotonic dynamics deviating strongly from a monoexponential decay and revealing slow beatings. The beatings indicate a two spin component behavior with a g -factor difference of Δ g ˜4 ×10-4 , much smaller than the Δ g expected for free and donor-bound electrons. This g -factor variation indicates efficient, but incomplete spin exchange averaging.

  7. Advanced magneto-optical microscopy: Imaging from picoseconds to centimeters - imaging spin waves and temperature distributions (invited

    Directory of Open Access Journals (Sweden)

    Necdet Onur Urs

    2016-05-01

    Full Text Available Recent developments in the observation of magnetic domains and domain walls by wide-field optical microscopy based on the magneto-optical Kerr, Faraday, Voigt, and Gradient effect are reviewed. Emphasis is given to the existence of higher order magneto-optical effects for advanced magnetic imaging. Fundamental concepts and advances in methodology are discussed that allow for imaging of magnetic domains on various length and time scales. Time-resolved imaging of electric field induced domain wall rotation is shown. Visualization of magnetization dynamics down to picosecond temporal resolution for the imaging of spin-waves and magneto-optical multi-effect domain imaging techniques for obtaining vectorial information are demonstrated. Beyond conventional domain imaging, the use of a magneto-optical indicator technique for local temperature sensing is shown.

  8. Resistance and the management of complicated skin and skin structure infections: the role of ceftobiprole

    Directory of Open Access Journals (Sweden)

    April Barbour

    2010-09-01

    Full Text Available April Barbour1, Hartmut Derendorf21GlaxoSmithKline, King of Prussia, PA, USA; 2Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, FL, USAAbstract: Antimicrobial resistant bacteria are an increasing concern due to the resulting increase in morbidity, mortality, and health-care costs associated with the administration of inadequate or delayed antimicrobial therapy. The implications of inadequate antimicrobial therapy in complicated skin and skin structure infections (cSSSIs have gained more attention recently, most likely due to the recent emergence of community-acquired methicillin resistant Staphylococcus aureus (MRSA and the already high prevalence of MRSA in the nosocomial setting. Due to the continuous threat of resistance arising and the limitations of currently available agents for the treatment of cSSSIs, it is necessary to develop new antimicrobials for this indication. Ceftobiprole medocaril, the prodrug of ceftobiprole, is a parental investigational cephalosporin for the treatment of cSSSIs displaying a wide-spectrum of activity against both Gram-positive and Gram-negative species, including MRSA. Ceftobiprole displays noncomplex linear pharmacokinetics, is eliminated primarily by glomerular filtration, and distributes to extracellular fluid. Additionally, it has been shown that the extent of distribution to the site of action with regard to cSSSIs, ie, the extracellular space fluid of subcutaneous adipose tissue and skeletal muscle, is expected to be efficacious, as free concentrations meet efficacy targets for most pathogens. Similar to other beta-lactams, it displays an excellent safety and tolerability profile with the primary adverse events being dysgeusia in healthy volunteers, resulting from the conversion of the prodrug to the active, and nausea in patients. Ceftobiprole has demonstrated noninferiority in two large-scale pivotal studies comparing it to vancomycin, clinical cure rates 93.3% vs

  9. Hearing aid fitting in older persons with hearing impairment: the influence of cognitive function, age, and hearing loss on hearing aid benefit

    Directory of Open Access Journals (Sweden)

    Meister H

    2015-02-01

    Full Text Available Hartmut Meister,1 Sebastian Rählmann,1 Martin Walger,2 Sabine Margolf-Hackl,3 Jürgen Kießling3 1Jean Uhrmacher Institute for Clinical ENT-Research, University of Cologne, Cologne, Germany; 2Department of Otorhinolaryngology, Head and Neck Surgery, University of Cologne, Cologne, Germany; 3Department of Othorhinolaryngology, Head and Neck Surgery, University of Giessen, Giessen, Germany Purpose: To examine the association of cognitive function, age, and hearing loss with clinically assessed hearing aid benefit in older hearing-impaired persons.Methods: Hearing aid benefit was assessed using objective measures regarding speech recognition in quiet and noisy environments as well as a subjective measure reflecting everyday situations captured using a standardized questionnaire. A broad range of general cognitive functions such as attention, memory, and intelligence were determined using different neuropsychological tests. Linear regression analyses were conducted with the outcome of the neuropsychological tests as well as age and hearing loss as independent variables and the benefit measures as dependent variables. Thirty experienced older hearing aid users with typical age-related hearing impairment participated.Results: Most of the benefit measures revealed that the participants obtained significant improvement with their hearing aids. Regression models showed a significant relationship between a fluid intelligence measure and objective hearing aid benefit. When individual hearing thresholds were considered as an additional independent variable, hearing loss was the only significant contributor to the benefit models. Lower cognitive capacity – as determined by the fluid intelligence measure – was significantly associated with greater hearing loss. Subjective benefit could not be predicted by any of the variables considered.Conclusion: The present study does not give evidence that hearing aid benefit is critically associated with cognitive

  10. PREFACE: 21st International Conference on Laser Spectroscopy - ICOLS 2013

    Science.gov (United States)

    Budker, Dmitry; Häffner, Hartmut; Müller, Holger

    2013-12-01

    videos of the reception and banquet presentations available at the conference web site https://icols.berkeley.edu/. On behalf of the organizing and program committees, Berkeley, October 2013 Dmitry Budker, Hartmut Häffner, and Holger Müller

  11. EE-drospirenone-levomefolate calcium versus EE-drospirenone + folic acid: folate status during 24 weeks of treatment and over 20 weeks following treatment cessation

    Directory of Open Access Journals (Sweden)

    Diefenbach K

    2013-04-01

    Full Text Available Konstanze Diefenbach,1 Dietmar Trummer,1 Frank Ebert,1 Michael Lissy,2 Manuela Koch,2 Beate Rohde,1 Hartmut Blode3 1Bayer HealthCare Pharmaceuticals, Berlin, Germany; 2Nuvisan GmbH, Neu-Ulm, Germany; 3Bayer HealthCare Pharmaceuticals Global R&D Center, Beijing, People's Republic of China Background: Adequate folate supplementation in the periconceptional phase is recommended to reduce the risk of neural tube defects. Oral contraceptives may provide a reasonable delivery vehicle for folate supplementation before conception in women of childbearing potential. This study aimed to demonstrate that a fixed-dose combination of an oral contraceptive and levomefolate calcium leads to sustainable improvements in folate status compared with an oral contraceptive + folic acid. Methods: This was a double-blind, randomized, parallel-group study in which 172 healthy women aged 18–40 years received ethinylestradiol (EE-drospirenone-levomefolate calcium or EE-drospirenone + folic acid for 24 weeks (invasion phase, and EE-drospirenone for an additional 20 weeks (folate elimination phase. The main objective of the invasion phase was to examine the area under the folate concentration time-curve for plasma and red blood cell (RBC folate, while the main objective of the elimination phase was to determine the duration of time for which RBC folate concentration remained ≥ 906 nmol/L after cessation of EE-drospirenone-levomefolate calcium. Results: Mean concentration-time curves for plasma folate, RBC folate, and homocysteine were comparable between treatment groups during both study phases. During the invasion phase, plasma and RBC folate concentrations increased and approached steady-state after about 8 weeks (plasma or 24 weeks (RBC. After cessation of treatment with levomefolate calcium, folate concentrations decreased slowly. The median time to RBC folate concentrations falling below 906 nmol/L was 10 weeks (95% confidence interval 8–12 weeks after cessation

  12. On consistent micromechanical estimation of macroscopic elastic energy, coherence energy and phase transformation strains for SMA materials

    Science.gov (United States)

    Ziółkowski, Andrzej

    2016-09-01

    An apparatus of micromechanics is used to isolate the key ingredients entering macroscopic Gibbs free energy function of a shape memory alloy (SMA) material. A new self-equilibrated eigenstrains influence moduli (SEIM) method is developed for consistent estimation of effective (macroscopic) thermostatic properties of solid materials, which in microscale can be regarded as amalgams of n-phase linear thermoelastic component materials with eigenstrains. The SEIM satisfy the self-consistency conditions, following from elastic reciprocity (Betti) theorem. The method allowed expressing macroscopic coherency energy and elastic complementary energy terms present in the general form of macroscopic Gibbs free energy of SMA materials in the form of semilinear and semiquadratic functions of the phase composition. Consistent SEIM estimates of elastic complementary energy, coherency energy and phase transformation strains corresponding to classical Reuss and Voigt conjectures are explicitly specified. The Voigt explicit relations served as inspiration for working out an original engineering practice-oriented semiexperimental SEIM estimates. They are especially conveniently applicable for an isotropic aggregate (composite) composed of a mixture of n isotropic phases. Using experimental data for NiTi alloy and adopting conjecture that it can be treated as an isotropic aggregate of two isotropic phases, it is shown that the NiTi coherency energy and macroscopic phase strain are practically not influenced by the difference in values of austenite and martensite elastic constants. It is shown that existence of nonzero fluctuating part of phase microeigenstrains field is responsible for building up of so-called stored energy of coherency, which is accumulated in pure martensitic phase after full completion of phase transition. Experimental data for NiTi alloy show that the stored coherency energy cannot be neglected as it considerably influences the characteristic phase transition

  13. Fabrication and mechanical properties of AlCoNiCrFe high-entropy alloy particle reinforced Cu matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jian, E-mail: chenjian@xatu.edu.cn [School of Materials Science and Chemical Engineering, Xi' an Technological University, Xi' an, Shaanxi 710021 (China); Niu, Pengyun; Wei, Ting [School of Materials Science and Chemical Engineering, Xi' an Technological University, Xi' an, Shaanxi 710021 (China); Hao, Liang [College of Architecture and Civil Engineering, Xi' an University of Science and Technology, Xi' an 710054 (China); Liu, Yunzi [School of Materials Science and Chemical Engineering, Xi' an Technological University, Xi' an, Shaanxi 710021 (China); Wang, Xianhui, E-mail: xhwang693@xaut.edu.cn [School of Materials Science and Engineering, Xi' an University of Technology, Xi' an, Shaanxi 710048 (China); Peng, Yuli [School of Materials Science and Chemical Engineering, Xi' an Technological University, Xi' an, Shaanxi 710021 (China)

    2015-11-15

    The AlCoNiCrFe high-entropy alloy was prepared by mechanical alloying and the AlCoNiCrFe high-entropy alloy reinforced Cu matrix composites were subsequently fabricated by powder metallurgy. The phase constituents and morphology of the alloying powders were characterized by X-ray diffractometer and scanning electron microscope, the microstructures of the Cu base composites were characterized by scanning electron microscope and transmission electron microscope, and the compression tests were made as well. The results show that the AlCoNiCrFe high-entropy alloy can form after milling for 24 h. During sintering process, no grain growth occurs and no intermetallic phases present in the AlCoNiCrFe high-entropy alloy in the Cu base composite. Compression tests show that the AlCoNiCrFe high-entropy alloy has a better strengthening effect than metallic glasses and the yield strength of the Cu matrix composite reinforced with the AlCoNiCrFe high-entropy alloy is close to the value predicted by the Voigt model based on the equal strain assumption. - Graphical abstract: AlCoNiCrFe HEA has a better strengthening effect than metallic glasses for particulate reinforced metal matrix composites. The yield strength of the Cu base composite reinforced with the AlCoNiCrFe HEA is close to the upper bound calculated by Voigt model. - Highlights: • AlCoNiCrFe high-entropy alloy was prepared by mechanical alloying. • A novel Cu base composite reinforced with AlCoNiCrFe was fabricated. • No grain growth and no intermetallic phase present in AlCoNiCrFe during sintering. • AlCoNiCrFe has a better strengthening effect than metallic glassy in composites.

  14. On consistent micromechanical estimation of macroscopic elastic energy, coherence energy and phase transformation strains for SMA materials

    Science.gov (United States)

    Ziółkowski, Andrzej

    2017-01-01

    An apparatus of micromechanics is used to isolate the key ingredients entering macroscopic Gibbs free energy function of a shape memory alloy (SMA) material. A new self-equilibrated eigenstrains influence moduli (SEIM) method is developed for consistent estimation of effective (macroscopic) thermostatic properties of solid materials, which in microscale can be regarded as amalgams of n-phase linear thermoelastic component materials with eigenstrains. The SEIM satisfy the self-consistency conditions, following from elastic reciprocity (Betti) theorem. The method allowed expressing macroscopic coherency energy and elastic complementary energy terms present in the general form of macroscopic Gibbs free energy of SMA materials in the form of semilinear and semiquadratic functions of the phase composition. Consistent SEIM estimates of elastic complementary energy, coherency energy and phase transformation strains corresponding to classical Reuss and Voigt conjectures are explicitly specified. The Voigt explicit relations served as inspiration for working out an original engineering practice-oriented semiexperimental SEIM estimates. They are especially conveniently applicable for an isotropic aggregate (composite) composed of a mixture of n isotropic phases. Using experimental data for NiTi alloy and adopting conjecture that it can be treated as an isotropic aggregate of two isotropic phases, it is shown that the NiTi coherency energy and macroscopic phase strain are practically not influenced by the difference in values of austenite and martensite elastic constants. It is shown that existence of nonzero fluctuating part of phase microeigenstrains field is responsible for building up of so-called stored energy of coherency, which is accumulated in pure martensitic phase after full completion of phase transition. Experimental data for NiTi alloy show that the stored coherency energy cannot be neglected as it considerably influences the characteristic phase transition

  15. Escape of Hydrogen from HD209458b

    Science.gov (United States)

    Erwin, Justin; Yelle, Roger; Koskinen, Tommi

    2017-04-01

    Recent modeling of the atmosphere of HD209458b has been used to interpret the Lyman-α line and other observations during transits. Koskinen et al. (2010) used a hydrostatic density profile in the thermosphere combined with the Voigt profile to estimate the Lyman-alpha transit depths for an array of model parameters. A detailed photochemical-dynamical model of the thermosphere was developed by Koskinen et al. (2013a) and used to again estimate model parameters to fit not only the Lyman-alpha transits, but also the transits in the O I, C II and Si III lines (Koskinen et al., 2013b). Recently, Bourrier and Lecavelier (2013) modeled the escape of hydrogen from the extended atmospheres of HD209458b and HD189733b and used the results to interpret Lyman-alpha observations. They included acceleration of hydrogen by radiation pressure and stellar wind protons to simulate the high velocity tails of the velocity distribution, arguing that the observations are explained by high velocity gas in the system while Voigt broadening is negligible. In this work we connect a free molecular flow (FMF) model similar to Bourrier and Lecavelier (2013) to the results of Koskinen et al. (2013b) and properly include absorption by the extended thermosphere in the transit model. In this manner, we can interpret the necessity of the various physical processes in matching the observed line profiles. Furthermore, the transit depths of this model can be used to re-evaluate the atmospheric model parameters to determine if they need to be adjusted due

  16. Quantitative XRD HW-IR plot for clay mineral domain size and lattice strain analyses

    Science.gov (United States)

    Wang, H. J.; Chen, D. Z.; Zhou, J.; Chen, T.; Wang, H.; Zhang, Z. Q.

    2003-04-01

    Based on integral-breadth method, the one of three basic XRD methods (Klug &Alexander, 1974), authors (2000) proposed a qualitative half width (HW)-intensity ratio (IR) plot for clay mineral domain size and lattice strain analyses. In this study, the quantitative HW-IR plot is further developed on the basis of i) the curve relation between the Voigt function and the Pearson VII function; ii) the relationship between the Kübler index and the Weaver index. By numerical simulating, it is derived a curve relation between shape indexes k of the Voigt function and u of the Pearson VII function. With this curve relation, k and u can be converted each other in an accuracy of ten thousandth and therefore the domain size and the lattice strain contributions can be precisely separated from an XRD peak according to Langford's (1978) formula. For micaceous minerals, the HW-IR plot requires only a pair of values of the Kübler index and the Weaver index from 1nm reflection. For other clay minerals, the plot needs a pair of values of the (00l) peak's half width and intensity ratio IR. IR is a ratio of peak maximum to the intensity at the position of maximum minus 0.422oΔ2Θ in CuKα radiation. This quantitative plot renders a mean dimension of clay particles perpendicular to the reflection plane (00l) and an approximate upper limit strain normal to d001. The accuracy for domain size analysis reaches one tenth of nanometre and that for the lattice strain analysis is in ten thousandth respectively. This plot method can be widely used with any digital X-ray diffractometer, whose XRD data can be converted into text format. Excel 5.0 or latter versions in both English and Chinese can well support the HW-IR plot. This study was supported by NNSFC (Grant No 40272022)

  17. Visco-elastic effects on wave dispersion in three-phase acoustic metamaterials

    Science.gov (United States)

    Krushynska, A. O.; Kouznetsova, V. G.; Geers, M. G. D.

    2016-11-01

    This paper studies the wave attenuation performance of dissipative solid acoustic metamaterials (AMMs) with local resonators possessing subwavelength band gaps. The metamaterial is composed of dense rubber-coated inclusions of a circular shape embedded periodically in a matrix medium. Visco-elastic material losses present in a matrix and/or resonator coating are introduced by either the Kelvin-Voigt or generalized Maxwell models. Numerical solutions are obtained in the frequency domain by means of k(ω)-approach combined with the finite element method. Spatially attenuating waves are described by real frequencies ω and complex-valued wave vectors k. Complete 3D band structure diagrams including complex-valued pass bands are evaluated for the undamped linear elastic and several visco-elastic AMM cases. The changes in the band diagrams due to the visco-elasticity are discussed in detail; the comparison between the two visco-elastic models representing artificial (Kelvin-Voigt model) and experimentally characterized (generalized Maxwell model) damping is performed. The interpretation of the results is facilitated by using attenuation and transmission spectra. Two mechanisms of the energy absorption, i.e. due to the resonance of the inclusions and dissipative effects in the materials, are discussed separately. It is found that the visco-elastic damping of the matrix material decreases the attenuation performance of AMMs within band gaps; however, if the matrix material is slightly damped, it can be modeled as linear elastic without the loss of accuracy given the resonator coating is dissipative. This study also demonstrates that visco-elastic losses properly introduced in the resonator coating improve the attenuation bandwidth of AMMs although the attenuation on the resonance peaks is reduced.

  18. Avaliação da metodologia analítica para determinação de beta-caroteno em macarrão fortificado Evaluation of the analytical methodology for the determination of beta-carotene in fortified pasta

    Directory of Open Access Journals (Sweden)

    Maricilda R. PEREIRA

    1998-04-01

    Full Text Available O beta-caroteno sintético pode ser adicionado tecnologicamente ao macarrão na forma de solução oleosa, emulsões dispersíveis em água ou sob a forma de esferas coloidais, com a finalidade de melhorar a sua cor e valor vitamínico. Todavia, a inexistência de uma metodologia confiável e especificamente testada para a extração e dosagem do beta-caroteno em macarrão enriquecido dificulta a avaliação da possível relevância nutricional da medida. O presente trabalho compara dois métodos de extração para produtos secos (LIVINGSTON, 1986 [método I] e RITTER & PURCELL, 1981 [método II] e um para verduras e frutas (RODRIGUEZ-AMAYA et al., 1976 [método III], quanto à eficiência de extração do beta-caroteno no macarrão cru e cozido. A matéria-prima utilizada foi um lote de macarrão produzido com quantidade conhecida de beta-caroteno, na forma de suspensão oleosa a 30%. Os resultados mostraram uma taxa de recuperação para beta-caroteno de 89 e 84% pelos métodos III e I, respectivamente, enquanto que o método II apresentou recuperação de apenas 44%. Conclue-se que, tanto os métodos I e III podem ser usados para quantificar o beta-caroteno em macarrão enriquecido. Por outro lado, a separação dos produtos de degradação do caroteno permite calcular o valor vitamínico real do macarrão cru e cozido. A superestimação dos valores vitamínicos, quando tais produtos não foram excluídos, foi de 24% para o macarrão cru e 25% para o cozido.Synthetic beta-carotene can be technologically added to macaroni either in the form of an oily solution, water-dispersible emulsions or colloidal beadlets with the objective of improving its color and vitamin-A value. The lack of a reliable and tested methodology specifically for the extraction and quantification of beta-carotene in enriched pasta prevents accurate evaluation of the possible nutritional significance of this measure. The present work compares two methods of extraction for

  19. Do deglaciated mountainslopes contribute significantly to paraglacial sediment fluxes?

    Science.gov (United States)

    Cossart, Etienne

    2013-04-01

    relation to paraglacial landsliding (Church & Ryder, 1972; Ritter & Ten Brink, 1986), whereas others have identified that some long-lived sediment dams can occur after the deposition of a landslide mass, so that no or little sediment exportation occurs (Korup, 2009; Cossart & Fort, 2008). We add to this debate by developing a typology of geomorphic couples, between paraglacial landslides and other geomorphic processes, and present simulations of sediment yield evolution since glacier disappearance. BALLANTYNE C.K., 2002 - A general model of paraglacial landscape response. The Holocene, 12, 371-376. BALLANTYNE C.K., 2003 - Paraglacial landform succession and sediment storage in deglaciated mountain valleys: theory and approaches to calibration. Zeitschrift für Geomorphologie, 32, 1-18. CHURCH M., & RYDER J.M., 1972 - Paraglacial sedimentation: a consideration of fluvial processes conditioned by glaciation. Geological Society of America Bulletin, 83, 3059-3072. COSSART É., & FORT M., 2008 - Sediment release and storage in early deglaciated areas: Towards an application of the exhaustion model from the case of Massif des Écrins (French Alps) since the Little Ice Age. Norsk Geografisk Tidsskrift - Norwegian Journal of Geography, 62, 115-131. KORUP O., 2009 - Linking landslides, hillslope erosion, and landscape evolution. Earth Surface Processes and Landforms, 34, 1315-1317. RITTER D.F., & TEN BRINK N.W., 1986 - Alluvial fan development and the glacial-glaciofluvial cycle. Nenana Valley, Alaska. Journal of Geology, 94, 613-615.

  20. Observation de la construction d'une compétence interculturelle dans des groupes exolingues en ligne Observing the development of intercultural competence in online exolingual group exchanges

    Directory of Open Access Journals (Sweden)

    Isabelle Audras

    2008-11-01

    Full Text Available Notre article interroge les domaines de recherche de la formation à distance et des échanges exolingues en groupes multiculturels en ligne dont l'objectif est l'acquisition d'une compétence interculturelle. Des publications récentes en Alao ont, tout à la fois, noté l'intérêt du milieu à développer de telles situations d'apprentissage et attiré l'attention sur les difficultés rencontrées. En reprenant les dix paramètres exposés par O'Dowd et Ritter, comme étant des facteurs de complexité, nous allons montrer que seuls deux d'entre eux sont spécifiques à notre problématique. Des deux paramètres restants, l'un concerne la scénarisation pédagogique spécifique à la compétence interculturelle, point qui se présente comme un espace de recherche et de développement sur lequel nous avons fait porter notre effort dans la version 2006 du projet Tridem exposée ici. Dans cette formation à distance, l'équipe pédagogique multi-institutionnelle a pensé et construit un scénario pédagogique tourné vers l'acquisition d'une compétence interculturelle selon le modèle exposé, notamment, par Byram. L'analyse des interactions multimodales recueillies au sein des environnements synchrones et asynchrones utilisés nous permet de mettre en correspondance certains moments de cette formation, où l'on observe une prise de risque, une ouverture à l'autre, etc., avec l'un des cinq savoirs décrits dans le modèle. Nous établissons ainsi une première série de correspondances entre des observables et l'acquisition d'une compétence interculturelle, au sens défini précédemment. L'étude d'un cas particulier d'échec de développement interroge sur les limites d'applicabilité de notre démarche ou sur la responsabilité du tuteur dans l'animation de groupes multiculturels.This article belongs to two research areas, distance education and the development of intercultural competence in online multicultural group exchanges. Recent

  1. Panorama dos Retornos dos IPO's sob o Ponto de Vista do Investidor = An Overview of the Returns of IPO's Under the Investor’s Sight

    Directory of Open Access Journals (Sweden)

    Jailson da Conceição Teixeira de Oliveira

    2015-04-01

    Full Text Available O objetivo deste trabalho é analisar os processos de abertura de capital de empresas que ocorreram no Brasil no período de 2004 a 2010 e avaliar se eles têm trazido benefícios para os investidores individualmente. Para analisar o desempenho do IPO no mercado acionário brasileiro serão empregados os métodos Market Adjusted Abnormal Returns (MAARSS e Buy-and-Hold Adjusted Returns (BHARS, os mesmos utilizados por Toniato (2007 que comparam o retorno de uma ação qualquer com o seu respectivo benchmarks. As rentabilidades calculadas a partir da data dos IPO's foram extraídas da plataforma Bloomberg. e mensuradas para as seguintes janelas: 1 dia, 1 ano e 3 anos, períodos semelhantes aos escolhidos por Ritter e Welch (2002. Os resultados obtidos nesse trabalho confirmam o fenômeno do underpricing na amostra e apontam ainda que os retornos de longo prazo são afetados pelo aquecimento do mercado no lançamento dos IPO's. Fica como sugestão para trabalhos futuros isolar o efeito provocado pelos coordenadores na precificação da oferta e, por conseguinte, no desempenho das ações, em função do aquecimento de mercado. The aim of this work is to analyze the processes of IPO companies that occurred in Brazil in the period of 2004-2010 and assess whether they have brought benefits to individual investors. To analyze the performance of the Brazilian stock market IPO methods Market Adjusted Abnormal Returns (MAARSS and Buy-and-Hold Adjusted Returns (BHARs are employed, the same used by Toniato (2007 that compare the return of any share with their respective benchmarks. The returns calculated from the date of IPO's were extracted from the Bloomberg platform and measured for the following windows: 1 day, 1 year and 3 years, being similar to those chosen by Ritter and Welch (2002 periods. The results of this work confirm the phenomenon of underpricing in the sample and also show that the long-term returns are affected by the of the market in the

  2. Accretion-powered Compact Binaries

    Science.gov (United States)

    Mauche, Christopher W.

    2003-12-01

    . Ruder, R. Whitehurst, A. King, J. C. Wheeler, S. Mineshige, M. Huang, S. W. Kim, Y. Tuchman, T. R. Kallman and J. A. Woods; 5. Magnetic M. T. Wolff, J. N. Imamura, K. S. Wood, J. H. Gardner, S. J. Litchfield, J. J. Brainerd, G. Chanmugan, K. Wu, J. Frank, T. Hanawa, K. Hirotani and N. Kawai; Part III. Novae S. Starrfield, R. M. Hjellming, A. B. Tomaney, A. W. Shafter, A. Cassatella, P. L. Selvelli, R. Gilmozzi, A. Bianchini, M. Friedjung, H. Ritter, M. J. Politano, M. Livio, R. F. Webbink, K. Horne, W. F. Welsh, R. A. Wade, J. Krauttler, M. A. J. Snijders, N. Vogt, L. H. Barrera, H. Barwig, K.-H Mantel, R. Gilmozzi, A. Shankar, A. Burkert, J. W. Truran and J. Hayes: Part IV. Evolution I. Iben Jr, M. S. Hjellming, R. E. Taam, M. Politano, F. D'Antona, I. Mazzitelli, H. Ritter, J. M. Hameury, A. R. King, J. P. Lasota, R. Popham, R. Narayan, J. Isern, J. Laybay, R. Canal, D. García, A. S. Fruchter, S. R. Kulkarni, R. W. Romani, A. Ray, W. Kluzniak, S. Miyaji and G. Chanmugam; Subject index; Star index.

  3. 一种基于能量人工神经元模型的自生长、自组织神经网络%An Energy Artificial Neuron Model Based Self-growing and Self-organizing Neural Network

    Institute of Scientific and Technical Information of China (English)

    班晓娟; 刘浩; 徐卓然

    2011-01-01

    本文结合近年生物学中神经科学的发展,针对神经胶质细胞对生物神经元网络的生长提供能量支持的特性,将神经胶质细胞的能量模型引入到人工神经元的概念模型中,提出了能量人工神经元(Energy artificial neuron,EAN)的概念模型,并给出了数学表述.同时,在能量人工神经元模型的基础上,实现了一种新型自生长、自组织人工神经元网络(EAN based serf-growing and self-organizing neural network,ESGSONN),ESGSONN将神经元中的能量、网络的熵增量及样本与神经元权值的相似度的竞争作为生长的条件,并对最优生长点中的获胜神经元进行单位步长调整.ESGSONN实现了快速生长、精确的样本数据分布密度保持、死神经元少的特性.本文使用经典的16种动物实验(Ritter and Kohonen,1989)验证了ESGSONN的正确性,并通过同SOFM、GCS等自组织网络的对比实验验证ESGSONN网络的特性.最后,本文对ESGSONN在高维空间中的本质进行了讨论.%In this paper, we established a new artificial neuron model called EAN (energy artificial neuron) based on the energy concept from the glial cells according to the recent achievements in the neuroscience field.We suggested a way to demonstrate EAN model in mathematics.In addition, we realized a self-growing and self-organizing neural network based on the EAN model called ESGSONN (EAN based self-growing and self-organizing neural network).ESGSONN considers the energy in EAN, the entropy productions in the network and the similarity (between the sample and neurons' weights) as its conditions of growing and competitions.Its main features are described as below: rapid growing, probability density preserving and few superfluous neurons.A classical experiment of 16-kind animals (aftet Ritter and Kohonen, 1989) proved ESGSONN can work correctly.We showed the new features of ESGSONN by comparing it with the traditional self-organizing networks such as SOFM and GCS

  4. Comparison of Neural Networks and Tabular Nearest Neighbor Encoding for Hyperspectral Signature Classification in Unresolved Object Detection

    Science.gov (United States)

    Schmalz, M.; Ritter, G.; Key, R.

    detections (Rfa). As proof of principle, we analyze classification of multiple closely spaced signatures from a NASA database of space material signatures. Additional analysis pertains to computational complexity and noise sensitivity, which are superior to Bayesian techniques based on classical neural networks. [1] Winter, M.E. "Fast autonomous spectral end-member determination in hyperspectral data," in Proceedings of the 13th International Conference On Applied Geologic Remote Sensing, Vancouver, B.C., Canada, pp. 337-44 (1999). [2] N. Keshava, "A survey of spectral unmixing algorithms," Lincoln Laboratory Journal 14:55-78 (2003). [3] Key, G., M.S. SCHMALZ, F.M. Caimi, and G.X. Ritter. "Performance analysis of tabular nearest neighbor encoding algorithm for joint compression and ATR", in Proceedings SPIE 3814:115-126 (1999). [4] Schmalz, M.S. and G. Key. "Algorithms for hyperspectral signature classification in unresolved object detection using tabular nearest neighbor encoding" in Proceedings of the 2007 AMOS Conference, Maui HI (2007). [5] Ritter, G.X., G. Urcid, and M.S. Schmalz. "Autonomous single-pass endmember approximation using lattice auto-associative memories", Neurocomputing (Elsevier), accepted (June 2008).

  5. Pill testing or drug checking in Australia: Acceptability of service design features.

    Science.gov (United States)

    Barratt, Monica J; Bruno, Raimondo; Ezard, Nadine; Ritter, Alison

    2017-06-20

    This study aimed to determine design features of a drug-checking service that would be feasible, attractive and likely to be used by Australian festival and nightlife attendees. Web survey of 851 Australians reporting use of psychostimulants and/or hallucinogens and attendance at licensed venues past midnight and/or festivals in the past year (70% male; median age 23 years). A drug-checking service located at festivals or clubs would be used by 94%; a fixed-site service external to such events by 85%. Most (80%) were willing to wait an hour for their result. Almost all (94%) would not use a service if there was a possibility of arrest, and a majority (64%) would not use a service that did not provide individual feedback of results. Drug-checking results were only slightly more attractive if they provided comprehensive quantitative results compared with qualitative results of key ingredients. Most (93%) were willing to pay up to $5, and 68% up to $10, per test. One-third (33%) reported willingness to donate a whole dose for testing: they were more likely to be male, younger, less experienced, use drugs more frequently and attend venues/festivals less frequently. In this sample, festival- or club-based drug-checking services with low wait times and low cost appear broadly attractive under conditions of legal amnesty and individualised feedback. Quantitative analysis of ecstasy pills requiring surrender of a whole pill may appeal to a minority in Australia where pills are more expensive than elsewhere. [Barratt MJ, Bruno R, Ezard N, Ritter A. Pill testing or drug checking in Australia: Acceptability of service design features. Drug Alcohol Rev 2017;00:000-000]. © 2017 Australasian Professional Society on Alcohol and other Drugs.

  6. Group additive values for the gas-phase standard enthalpy of formation, entropy and heat capacity of oxygenates.

    Science.gov (United States)

    Paraskevas, Paschalis D; Sabbe, Maarten K; Reyniers, Marie-Françoise; Papayannakos, Nikos; Marin, Guy B

    2013-11-25

    A complete and consistent set of 60 Benson group additive values (GAVs) for oxygenate molecules and 97 GAVs for oxygenate radicals is provided, which allow to describe their standard enthalpies of formation, entropies and heat capacities. Approximately half of the GAVs for oxygenate molecules and the majority of the GAVs for oxygenate radicals have not been reported before. The values are derived from an extensive and accurate database of thermochemical data obtained by ab initio calculations at the CBS-QB3 level of theory for 202 molecules and 248 radicals. These compounds include saturated and unsaturated, α- and β-branched, mono- and bifunctional oxygenates. Internal rotations were accounted for by using one-dimensional hindered rotor corrections. The accuracy of the database was further improved by adding bond additive corrections to the CBS-QB3 standard enthalpies of formation. Furthermore, 14 corrections for non-nearest-neighbor interactions (NNI) were introduced for molecules and 12 for radicals. The validity of the constructed group additive model was established by comparing the predicted values with both ab initio calculated values and experimental data for oxygenates and oxygenate radicals. The group additive method predicts standard enthalpies of formation, entropies, and heat capacities with chemical accuracy, respectively, within 4 kJ mol(-1) and 4 J mol(-1) K(-1) for both ab initio calculated and experimental values. As an alternative, the hydrogen bond increment (HBI) method developed by Lay et al. (T. H. Lay, J. W. Bozzelli, A. M. Dean, E. R. Ritter, J. Phys. Chem.- 1995, 99, 14514) was used to introduce 77 new HBI structures and to calculate their thermodynamic parameters (Δ(f)H°, S°, C(p)°). The GAVs reported in this work can be reliably used for the prediction of thermochemical data for large oxygenate compounds, combining rapid prediction with wide-ranging application.

  7. A spectroscopic orbit for the late-type Be star β CMi

    Science.gov (United States)

    Dulaney, Nick; Richardson, Noel; Gerhartz, Cody; Bjorkman, Jon Eric; Bjorkman, Karen S.; Carciofi, Alex C.; Wang, Luqian; Morrison, Nancy D.; Klement, Robert; Ritter Observing Team

    2017-01-01

    The late-type Be star beta CMi is remarkably stable compared to other Be stars that have been studied. This has led to a realistic model of the outflowing Be disk by Klement et al. (2015) These results showed that the disk is likely truncated at a finite radius from the star, which is easily accomplished by a binary companion in orbit. We report on an analysis of the Ritter Observatory spectroscopic archive of beta CMi in hopes of discovering evidence of the elusive companion. We detect orbital motion caused by a companion from small shifts in the H-alpha emission line. We then compared the small changes in the violet-to-red peak height changes (V/R) with the orbital motion. While some V/R variability seems to be present in the H-alpha profile, there is only weak evidence that it follows the orbital motion, as suggested by recent Be binary models by Panoglou et al. (2016). We also analyze several epochs of near-infrared moderate resolution spectra from the InfraRed Telescope Facility with the SpeX spectrograph. Near-infrared spectra show variations of the Pa-beta and Br-gamma lines, suggesting structure could be present in the inner parts of the Be disk. These results suggest that beta CMi is similar to several other Be stars, and is a product of binary evolution where Roche lobe overflow has spun up the current Be star, likely leaving a hot subdwarf or white dwarf in orbit around the star. Unfortunately, no sign of this star is found in the very limited archive of International Ultraviolet Explorer spectra, so future UV studies of the system are necessary.We are grateful for support of the NSF REU program at the University of Toledo through NSF grant 1262810 and addtional support from the NSF under grant AST-1412135.

  8. 17. Kassel symposium energy systems technology. Structures and grids for the future energy supply; 17. Kasseler Symposium Energie-Systemtechnik. Strukturen und Netze fuer die Energieversorgung von Morgen

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    Within the 17th Kassel symposium from 11th to 12th October, 2012, in Kassel (Federal Republic of Germany), the following lectures were held: (1) E-Energy - the art of flexibilization between market and regulation (Michael Wedler); (2) The model region Harz (Florian Schloegl); (3) The role of IKT at the transformation of the energy supply - Chances for new business ideas (Arnold Picot); (4) Standardized connection of plants to IEC 61850 (Martin Winter); (5) Implementation of a IKT infrastructure for a virtual power plant in the model region Harz (Manuel Wickert); (6) OGEMA2.0 - Smart grid meets smart home (David Nestle); (7) Evaluation of the grid stability of a purely regenerative power supply (Kaspar Knorr); (8) Biogas plants and storage for the integration of renewable energies (Patrick Hochloff); (9) moma Architecture and functions in the intelligent energy system (Andreas Kiessling); (10) Power hub - showing the full potential of the VPP technology (Andreas Bjerre); (11) Implementation of electricity grids, heat grids and traffic grids - Potentials, requirements and efficiencies (Wolfram Wellssow); (12) Exploration of the regional distribution grid as a basis for the implementation of smart grids using the RegModHarz project as an example (Christian Roehrig); (13) New design and works management of distribution grids in decentralized supply structures (Martin Braun); (14) Advantages and challenges of the coupling of natural gas distribution systems and power distribution systems (Herbert Bauer); (15) Acceptance of renewable energies in the region Harz (Amelie Fechner); (16) Business models for a future 100 per cent supply of renewable energies (Peer Ritter).

  9. RELATIONSHIP BETWEEN THE PATTERN OF METHYLATION OF CALCITONIN GENE AND ACTIVITY OF METHYLTRANSFERASE in 8 Tumor Cell Lines

    Institute of Scientific and Technical Information of China (English)

    BAI; Zhi-yong

    2001-01-01

    [1]Baylin SB, Fearon ER, Vogeletein B, et al. Hyper- methylation of 5' the region of the calcitonin gene is a property of human lymphoid and acute myeloid malignancies [J]. Blood 1987; 70:412.[2]Nelkin BD, Przepiorka D, Burke PJ, et al. Abnormal methylation of the calcitonin gene marks progression of chronic myelogenous leukemia [J]. Blood 1991; 77: 2431.[3]Ritter M, Kant EDe, Huhn D, et al. Detection of DNA methylation in the calcitonin gene in human leukemias using differential polymerase chain reaction [J]. Leukemia 1995; 9:915.[4]Wu SL, Xie GL, Bai RK, et al. Semi-quantitative study of calcitonin gene methylation in myelodysplastic syndrome [J]. Chin Med J 1998; 111:690.[5]Admas RL, Rinaldi A, Seivwright CA. Microassay for DNA methyltranferase [J]. J Biochem Biophys Methods 1991; 22:19.[6]Bai ZY, Xu GB, Wu SL. Detection of DNA- methyl- tranferase activity of leukemia cells with radiology microassay [J]. J Beijing Med Univ 2000; 32:76.[7]Issa J, Veritino PM, Wu J, et al. Increased cytosine DNA- Methyltranferase activity during colon cancer pro- gression [J]. J Natl Cancer Inst 1993; 85:1235.[8]Vertino PM, Yen RW, Gao J, et al. De novo methylation of CpG islands sequences in human fibroblasts overexpression DNA (cytosine-5-) methyltranferase [J]. Mol cell Bio 1996; 16:4555.[9]Robertson KD, Uzvolgyi E, Liang G, et al. The human DNA methyltranferase (DNMTs) 1, 3a and 3b: coordinate mRNA expression in normal tissue and overexpression in tumors [J]. Nucleic Acids Res 1999; 27:2291.[10]Okano M, Bell DW, Haber DA, et al. DNA methyl- tranferases Dnmt3a and Dnmt3b are essential for de novo methylation and mammalian development [J]. Cell 1999; 99:247.

  10. Chemical aspects of cylinder corrosion and a scenario for hole development

    Energy Technology Data Exchange (ETDEWEB)

    Barber, E.J. [Martin Marietta Energy Systems, Oak Ridge, TN (United States)

    1991-12-31

    In June 1990, two cylinders in the depleted UF{sub 6} cylinder storage yards at Portsmouth were discovered to have holes in their walls at the valve-end stiffening ring at a point below the level of the gas-solid interface of the UF{sub 6}. The cylinder with the larger hole, which extended under the stiffening ring, was stacked in a top row 13 years ago. The cylinder with the smaller hole had been stacked in a bottom row 4 years ago. The lifting lugs of the adjacent cylinders pointed directly at the holes. A Cylinder Investigating Committee was appointed to determine the cause or causes of the holes and to assess the implications of these findings. This report contains a listing of the chemically related facts established by the Investigating Committee with the cooperation of the Operations and Technical Support Divisions at the Portsmouth Gaseous Diffusion Plant, the scenario developed to explain these findings and some implications of this scenario. In summary, the interrelated reactions of water, solid UF{sub 6} and iron presented by R. L. Ritter are used to develop a scenario which explains the observations and deductions made during the investigation. The chemical processes are intimately related to the course of the last three of the four stages of hole development. A simple model is proposed which permits semiquantitative prediction of such information as the HF loss rates as a function of time, the rate of hole enlargement, the time to hydrolyze a cylinder of UF{sub 6} and the approximate size of the hole. The scenario suggests that the environmental consequences associated with a developing hole in a depleted UF{sub 6} cylinder are minimal for the first several years but will become significant if too many years pass before detection. The overall environmental picture is presented in more detail elsewhere.

  11. La síntesis en geografía

    Directory of Open Access Journals (Sweden)

    Daniel Benjamin Aché Aché

    2010-01-01

    Full Text Available Uno de los conceptos más debatidos en los anales de la geografía desde los tiempos modernos es el de la síntesis geográfica, su significado, alcance y propósito han tenido repercusiones muy diversas. Su origen se encuentra en la búsqueda de la síntesis regional por los geógrafos agrupados en torno a la escuela clásica francesa. No obstante, en corrientes anteriores es posible identificar elementos que sugieren un manejo de los contenidos teóricos, que posteriormente se denominó síntesis geográfica. En el pensamiento ratzeliano, la geografía persigue explicar la síntesis suprema de las relaciones totales de la superficie de la tierra, al igual que en Ritter, en su concepto de integridad-globalidad, se encuentran referentes; e incluso, en el siglo I, el pensamiento de Estrabón, y concretamente en su visión integradora de los fenómenos tanto físicos como humanos, es posible vincular el concepto de síntesis geográfica. Las sucesivas corrientes: geografía humana, cuantitativa, humanística, de bienestar, como producto social, postmodernista y geotecnológica (geomática, con diferentes matices, emplean en sus argumentaciones la síntesis geográfica. La geografía radical, por su parte, pone, bajo interrogación, su validez en el trabajo científico. Es en la geografía aplicada donde su arraigo es definitorio.

  12. Glutamine-dependent carbamoyl-phosphate synthetase and other enzyme activities related to the pyrimidine pathway in spleen of Squalus acanthias (spiny dogfish).

    Science.gov (United States)

    Anderson, P M

    1989-07-15

    The first two steps of urea synthesis in liver of marine elasmobranchs involve formation of glutamine from ammonia and of carbamoyl phosphate from glutamine, catalysed by glutamine synthetase and carbamoyl-phosphate synthetase, respectively [Anderson & Casey (1984) J. Biol. Chem. 259, 456-462]; both of these enzymes are localized exclusively in the mitochondrial matrix. The objective of this study was to establish the enzymology of carbamoyl phosphate formation and utilization for pyrimidine nucleotide biosynthesis in Squalus acanthias (spiny dogfish), a representative elasmobranch. Aspartate carbamoyltransferase could not be detected in liver of dogfish. Spleen extracts, however, had glutamine-dependent carbamoyl-phosphate synthetase, aspartate carbamoyltransferase, dihydro-orotase, and glutamine synthetase activities, all localized in the cytosol; dihydro-orotate dehydrogenase, orotate phosphoribosyltransferase, and orotidine-5'-decarboxylase activities were also present. Except for glutamine synthetase, the levels of all activities were very low. The carbamoyl-phosphate synthetase activity is inhibited by UTP and is activated by 5-phosphoribosyl 1-pyrophosphate. The first three enzyme activities of the pyrimidine pathway were eluted in distinctly different positions during gel filtration chromatography under a number of different conditions; although complete proteolysis of inter-domain regions of a multifunctional complex during extraction cannot be excluded, the evidence suggests that in dogfish, in contrast to mammalian species, these three enzymes of the pyrimidine pathway exist as individual polypeptide chains. These results: (1) establish that dogfish express two different glutamine-dependent carbamoyl-phosphate synthetase activities, (2) confirm the report [Smith, Ritter & Campbell (1987) J. Biol. Chem. 262, 198-202] that dogfish express two different glutamine synthetases, and (3) provide indirect evidence that glutamine may not be available in liver for

  13. Clinical feasibility of exercise-based A-V interval optimization for cardiac resynchronization: a pilot study.

    Science.gov (United States)

    Choudhuri, Indrajit; MacCarter, Dean; Shaw, Rachael; Anderson, Steve; St Cyr, John; Niazi, Imran

    2014-11-01

    One-third of eligible patients fail to respond to cardiac resynchronization therapy (CRT). Current methods to "optimize" the atrio-ventricular (A-V) interval are performed at rest, which may limit its efficacy during daily activities. We hypothesized that low-intensity cardiopulmonary exercise testing (CPX) could identify the most favorable physiologic combination of specific gas exchange parameters reflecting pulmonary blood flow or cardiac output, stroke volume, and left atrial pressure to guide determination of the optimal A-V interval. We assessed relative feasibility of determining the optimal A-V interval by three methods in 17 patients who underwent optimization of CRT: (1) resting echocardiographic optimization (the Ritter method), (2) resting electrical optimization (intrinsic A-V interval and QRS duration), and (3) during low-intensity, steady-state CPX. Five sequential, incremental A-V intervals were programmed in each method. Assessment of cardiopulmonary stability and potential influence on the CPX-based method were assessed. CPX and determination of a physiological optimal A-V interval was successfully completed in 94.1% of patients, slightly higher than the resting echo-based approach (88.2%). There was a wide variation in the optimal A-V delay determined by each method. There was no observed cardiopulmonary instability or impact of the implant procedure that affected determination of the CPX-based optimized A-V interval. Determining optimized A-V intervals by CPX is feasible. Proposed mechanisms explaining this finding and long-term impact require further study. ©2014 Wiley Periodicals, Inc.

  14. 上海社会科学院历史研究所资料室珍藏"西文汉学旧籍"简介(四)

    Institute of Scientific and Technical Information of China (English)

    马军

    2002-01-01

    @@ 三辞书类 1、A Chinese-English Dictionary(),英国剑桥大学汉学教授翟理思(Herbert A.Giles)编,1892年在沪首版.是继马礼逊(Robert Morrison)的A Dictionary of the Chinese Language(1819)、麦都思(W.H.Medhurst)的Chinese and English Dictionary(1843)、罗存德(W.Lobscheid)的A Chinese and English Dictionary(1871)和卫三畏(Samuel Wells Williams)的A Syllabic Dictionary of the Chinese Language(1874)之后最重要的汉英字典,所收的词汇、语句较以前任何一部同类字典都多.本室藏有1912年上海别发洋行的修订版,大16开本,正文1711页,并有多种附录.中文字照威妥玛--翟理思式拼音,从A至Z按比26个字母顺序排列.除对单个汉字有解释外,还有对该字词条的释义.字典首版以后,德国汉学家查赫(Erwin Ritter von Zach)曾核查出大大小小千余条错误,编者在再版时绝大多数予以改正.翟理思因1912年的修订版,获得了同年的欧洲汉学最高奖--儒莲奖(Prix Stanislas Julien).

  15. The Cyborg Astrobiologist: matching of prior textures by image compression for geological mapping and novelty detection

    Science.gov (United States)

    McGuire, P. C.; Bonnici, A.; Bruner, K. R.; Gross, C.; Ormö, J.; Smosna, R. A.; Walter, S.; Wendt, L.

    2014-07-01

    We describe an image-comparison technique of Heidemann and Ritter (2008a, b), which uses image compression, and is capable of: (i) detecting novel textures in a series of images, as well as of: (ii) alerting the user to the similarity of a new image to a previously observed texture. This image-comparison technique has been implemented and tested using our Astrobiology Phone-cam system, which employs Bluetooth communication to send images to a local laptop server in the field for the image-compression analysis. We tested the system in a field site displaying a heterogeneous suite of sandstones, limestones, mudstones and coal beds. Some of the rocks are partly covered with lichen. The image-matching procedure of this system performed very well with data obtained through our field test, grouping all images of yellow lichens together and grouping all images of a coal bed together, and giving 91% accuracy for similarity detection. Such similarity detection could be employed to make maps of different geological units. The novelty-detection performance of our system was also rather good (64% accuracy). Such novelty detection may become valuable in searching for new geological units, which could be of astrobiological interest. The current system is not directly intended for mapping and novelty detection of a second field site based on image-compression analysis of an image database from a first field site, although our current system could be further developed towards this end. Furthermore, the image-comparison technique is an unsupervised technique that is not capable of directly classifying an image as containing a particular geological feature; labelling of such geological features is done post facto by human geologists associated with this study, for the purpose of analysing the system's performance. By providing more advanced capabilities for similarity detection and novelty detection, this image-compression technique could be useful in giving more scientific autonomy

  16. A Thermodynamic History of the Solar Constitution — II: The Theory of a Gaseous Sun and Jeans' Failed Liquid Alternative

    Directory of Open Access Journals (Sweden)

    Robitaille P.-M.

    2011-07-01

    Full Text Available In this work, the development of solar theory is followed from the concept that the Sun was an ethereal nuclear body with a partially condensed photosphere to the creation of a fully gaseous object. An overview will be presented of the liquid Sun. A powerful lineage has brought us the gaseous Sun and two of its main authors were the direct sci- entific descendants of Gustav Robert Kirchhoff: Franz Arthur Friedrich Schuster and Arthur Stanley Eddington. It will be discovered that the seminal ideas of Father Secchi and Herv ́ e Faye were not abandoned by astronomy until the beginning of 20th century. The central role of carbon in early solar physics will also be highlighted by revisit- ing George Johnstone Stoney. The evolution of the gaseous models will be outlined, along with the contributions of Johann Karl Friedrich Z ̈ ollner, James Clerk Maxwell, Jonathan Homer Lane, August Ritter, William Thomson, William Huggins, William Edward Wilson, George Francis FitzGerald, Jacob Robert Emden, Frank Washington Very, Karl Schwarzschild, and Edward Arthur Milne. Finally, with the aid of Edward Arthur Milne, the work of James Hopwood Jeans, the last modern advocate of a liquid Sun, will be rediscovered. Jeans was a staunch advocate of the condensed phase, but deprived of a proper building block, he would eventually abandon his non-gaseous stars. For his part, Subrahmanyan Chandrasekhar would spend nine years of his life studying homogeneous liquid masses. These were precisely the kind of objects which Jeans had considered for his liquid stars.

  17. Electrical characteristics of the hydroxyapatite for biomedical applications; Caracteristicas electricas de la hidroxiapatita para aplicaciones biomedicas

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Buisan N, M.G.; Mendez G, M.M. [Laboratorio de Corrosion, ESFM-IPN, 07738 Mexico D.F. (Mexico)

    2006-07-01

    The electric characteristics of hydroxyapatite films were studied (HAP) deposited on metallic substrates oxidized naturally. The substrates was made of steel 316L and of titanium. These materials are used in reconstructive surgery for prosthesis and osseous implants. The studies were carried out with the techniques of potentiostatic polarization and faraday impedance. The potentiostatic polarization reveals that the very well-known piezoelectricity of the HAp subsists after the coating processes (it captures thermal and spray-pyrolysis). Its also revealed a semiconductor behavior of the HAp that until now had not been reported. This characteristic is important, by its relationship with the stability of the HAp coating in front of corrosion processes in the alive tissues. The results of the impedance tests were mathematically analyzed starting from the Nyquist diagrams, of Bode and of power. The physical interpretation is presented under the form of equivalent circuits (CE). In the case of the HAp on a steel 316L substrate, the CE is a Rancles-Voigt module that corresponds to the behavior of a dielectric with flights. In the case of the titanium substrate an element of constant phase appears to high frequencies (CPE), in series with the Rancles-Voigt module. The CPE reveals the presence of a rectifier of the metal/SC-n type that only it could be located in the interface among the titanium and its natural oxide (TiO{sub 2}). The absence of the CPE in the case of the steel 316L substrate indicates that the natural oxide (Cr{sub 2}O{sub 3}) it doesn't form with the steel a Schottky diode, possibly because the chromite is as a SC-n degenerate. On the interface Ti/TiO{sub 2} exists results qualitatively identical by other researchers that have worked with the same impedance technique, but applied by humid via (EIS). The CE that have proposed are based on the anodic processes of accretion/dissolution of the film at low pH. This proposal is questioned by our results

  18. Transparency of the 2 μm (5000 cm-1) methane window in Titan's atmosphere and impact on retrieved surface reflectivity

    Science.gov (United States)

    Rannou, Pascal; Seignovert, Benoit; Le Mouélic, Stéphane; Sotin, Christophe

    2016-10-01

    The study of Titan properties with remote sensing relies on a good knowledge of the atmosphere properties. The in-situ observations made by Huygens combined with recent advances in the definition of methane properties enable to model and interpret observations with a very good accuracy. Thanks to these progresses, we can analyze in this work the observations made at the limb of Titan in order to retrieve information on the haze properties as its vertical profiles and its spectral behaviour along the VIMS/Cassini range (from 0.88 to 5.1 μm). However, for applications to real atmospheres, one need to account for the widening of the spectroscopic lines (e.g., Voigt profile) and apply an empirical cut-off of the far wings. In general, this is a multiplying function of the wavenumber, f(ν), applied to the Voigt profile that allows a faster decay of the wing profile beyond a given distance from the center of the line ν0 : f(ν)=1 if |ν- ν0| ≤ Δν, and f(ν)=exp(-|ν- ν0|/ σ) if |ν- ν0| > Δν. Although the 2-μm window is apparently straitforward to model, it appears that the standard cut-off parameters (that is Δν ~ 26 cm-1 and σ ~ 120 cm-1) which is used for other windows in Titan's atmosphere is not adequat for this window. Other sets of parameter must be used to reproduce Titan spectrum at 2 μm. However, there is no convergence of the results between these works and a large variety of cut-off parameters are used. Alternatively, it was found that some gas absorptions (ethane and another unknown gas) leave a signature around 2-μm and also affect the transparency in this window. In our study we make an exhaustive investigation on the cut-off parameters to determine which are the best couples of parameters to fit the 2-μm window. We also evaluated how gaseous absorptions can allow to reach a satisfactory agreement and, especially, if it allows to match observations with the standard cut-off. Finally, we investigate the impact of the different solutions

  19. A Boreal high-resolution composite carbon isotope record of the Albian to Turonian interval from the North German Basin

    Science.gov (United States)

    Bornemann, André; Erbacher, Jochen; Huck, Stefan; Heimhofer, Ulrich

    2017-04-01

    We present a potentially complete, six-hundred-meters-thick composite record of high-resolution bulk-rock carbon isotope data from northern Germany covering the topmost Lower Albian to Lower Turonian interval. The established composite record consists of more than 1700 measurements ana-lyzed from seven drill sites including the Kirchrode I and II cores (Nebe, 1999; Fenner, 2001), the Anderten I and II cores (Bornemann et al., 2017), two industrial cores Wunstorf 2011/2 and 2011/8 as well as the Wunstorf research core (Voigt et al., 2008). In the central North German Basin the Albian is represented by a several hundred meters-thick succession of clays and clayey marls, whereas the Lower Cenomanian is characterized by the transition from clayey to chalky sedimentation. The latter prevailed during the remaining Cenomanian. The top of the studied succession is marked by the prominent black shales of the Cenomanian-Turonian boundary event (CTBE). The isotope records display the carbon isotope expression of the Oceanic Anoxic Events 1d and 2 as well as the Lower and Mid-Cenomanian Events (LCE, MCE). The applied integrat-ed approach of high-resolution chemostratigraphy and revised biostratigraphy gives way for a substantial improvement of the Boreal Cretaceous stratigraphy. Fenner, J. (2001) The Kirchrode I and II boreholes: technical details and evidence on tectonics, and the palaeoceanographic development during the Albian. Palaeogeogr. Palaeoclimatol. Palaeoecol., 174, 33-65. Nebe, D. (1999) Zyklenuntersuchungen an unterkretazischen Sedimenten in NW-Deutschland - Nachweisbarkeit von Milankovitch-Zyklen [PhD thesis, Ruhr-Univ. Bochum]. Bornemann, A., Erbacher, J., Heldt, M., Kollaske, T., Lübke, N., Huck, S., Vollmar, N.M., Wilmsen, M. (2017) The Albian-Cenomanian transition and Oceanic Anoxic Event 1d - an example from the Boreal Realm. Sedimentol. [doi:10.1111/sed.12347]. Voigt, S., Erbacher, J., Mutterlose, J., Weiss, W., Westerhold, T., Wiese, F., Wilmsen, M

  20. Valence-Shell Excitations of Nitrous Oxide Studied by Fast Electron Impact

    Institute of Scientific and Technical Information of China (English)

    LIU Ya-Wei; WANG You-Yan; ZHU Lin-Fan

    2012-01-01

    The valence-shell excitations of nitrous oxide are studied by fast electron energy loss spectroscopy.From the spectra measured at 2.5keV and scattering angles of 3.5°-8.5°,it is found that the asymmetric peak of the transition B 1△ can be well fitted by Haarhoff-Van der Linde function,while the symmetric peaks of the transitions of C1Π and D1∑+ can be well fitted by the Voigt function.The parameters of the peak profiles of B1△,C1Π and D1∑+,i.e.,their energy level positions and linewidths,are determined.With the aid of these parameters,the overlapping spectra measured at the low-energy electron impact can be deconvolved,which provides the possibility to determine the quantitative differential cross sections.The present results also show that the peak profiles of the transitions of B1△,C1Π and D1∑+ are independent of the momentum transfer.%The valence-shell excitations of nitrous oxide are studied by fast electron energy loss spectroscopy. From the spectra measured at 2.5keV and scattering angles of 3.5°-8.5°, it is found that the asymmetric peak of the transition B1A can be well fitted by Haarhoff-Van der Linde function, while the symmetric peaks of the transitions of C1II. And D1∑+ can be well fitted by the Voigt function. The parameters of the peak profiles of B1△, C1II and D1∑+, I.e., their energy level positions and linewidths, are determined. With the aid of these parameters, the overlapping spectra measured at the low-energy electron impact can be deconvolved, which provides the possibility to determine the quantitative differential cross sections. The present results also show that the peak profiles of the transitions of B1△, C1II and D1∑+ are independent of the momentum transfer.

  1. Determination of the elastic constants of portlandite by Brillouin spectroscopy

    KAUST Repository

    Speziale, S.

    2008-10-01

    The single crystal elastic constants Cij and the shear and adiabatic bulk modulus of a natural portlandite (Ca(OH)2) crystal were determined by Brillouin spectroscopy at ambient conditions. The elastic constants, expressed in GPa, are: C11 = 102.0(± 2.0), C12 = 32.1(± 1.0), C13 = 8.4(± 0.4), C14 = 4.5(± 0.2), C33 = 33.6(± 0.7), C44 = 12.0(± 0.3), C66 = (C11-C12)/2 = 35.0(± 1.1), where the numbers in parentheses are 1σ standard deviations. The Reuss bounds of the adiabatic bulk and shear moduli are K0S = 26.0(± 0.3) GPa and G0 = 17.5(± 0.4) GPa, respectively, while the Voigt bounds of these moduli are K0S = 37.3(± 0.4) GPa and G0 = 24.4(± 0.3) GPa. The Reuss and Voigt bounds for the aggregate Young\\'s modulus are 42.8(± 1.0) GPa and 60.0(± 0.8) GPa respectively, while the aggregate Poisson\\'s ratio is equal to 0.23(± 0.01). Portlandite exhibits both large compressional elastic anisotropy with C11/C33 = 3.03(± 0.09) equivalent to that of the isostructural hydroxide brucite (Mg(OH)2), and large shear anisotropy with C66/C44 = 2.92(± 0.12) which is 11% larger than brucite. The comparison between the bulk modulus of portlandite and that of lime (CaO) confirms a systematic linear relationship between the bulk moduli of brucite-type simple hydroxides and the corresponding NaCl-type oxides. © 2008 Elsevier Ltd. All rights reserved.

  2. Sensitivity analysis of effective fluid and rock bulk modulus due to changes in pore pressure, temperature and saturation

    Science.gov (United States)

    Bhakta, Tuhin; Avseth, Per; Landrø, Martin

    2016-12-01

    Fluid substitution plays a vital role in time-lapse seismic modeling and interpretation. It is, therefore, very important to quantify as exactly as possible the changes in fluid bulk modulus due to changes in reservoir parameters. In this paper, we analyze the sensitivities in effective fluid bulk modulus due to changes in reservoir parameters like saturation, pore-pressure and temperature. The sensitivities are analyzed for two extreme bounds, i.e. the Voigt average and the Reuss average, for various fluid combinations (i.e. oil-water, gas-water and gas-oil). We quantify that the effects of pore-pressure and saturation changes are highest in the case of gas-water combination, while the effect of temperature is highest for oil-gas combination. Our results show that sensitivities vary with the bounds, even for same amount of changes in any reservoir parameter. In 4D rock physics studies, we often neglect the effects of pore-pressure or temperature changes assuming that those effects are negligible compare to the effect due to saturation change. Our analysis shows that pore-pressure and temperature changes can be vital and sometimes higher than the effect of saturation change. We investigate these effects on saturated rock bulk modulus. We first compute frame bulk modulus using the Modified Hashin Shtrikman (MHS) model for carbonate rocks and then perform fluid substitution using the Gassmann equation. We consider upper bound of the MHS as elastic behavior for stiffer rocks and lower bound of the MHS as elastic behavior for softer rocks. We then investigate four various combinations: stiff rock with upper bound (the Voigt bound) as effective fluid modulus, stiff rock with lower bound (Reuss bound) as effective fluid modulus, soft rock with upper bound as effective fluid modulus and soft rock with lower bound as effective fluid modulus. Our results show that the effect of any reservoir parameter change is highest for soft rock and lower bound combination and lowest

  3. Effect of substitution Fe2+on physical properties of MgSiO3 perovskite at high temperature and high pressure∗%Fe2取代对MgSiO3钙钛矿高温高压物性的影响

    Institute of Scientific and Technical Information of China (English)

    吴迪; 赵纪军; 田华

    2013-01-01

      (Mg, Fe)SiO3钙钛矿是下地幔中最主要的候选矿物成分之一,关于其高温高压特性的研究对于深层地幔状态的理解和地震波变化规律的探索具有重要意义.应用第一性原理计算了MgSiO3和(Mg0.75, Fe0.25)SiO3在0—140 GPa静水压范围内的晶体结构和弹性模量,并由Voigt-Reuss-Hill方程计算了地震波速随压力的变化,利用准简谐近似下的Debye模型模拟了高温效应,分析了Fe2+取代Mg2+后镁铁钙钛矿弹性和热学性质的变化,推断Fe2+取代行为软化了MgSiO3等含镁的地球深部矿物的地震波速.为解释地幔中某些区域的地震波速软化现象提供了一个有力的理论依据.%(Mg, Fe)SiO3-perovskite is currently considered to be the most abundant mineral in the earth’s lower mantle. Its behavior at high temperature and high pressure is crucial for interpreting conditions at the deep level of the mantle, variations of seismic waves, and so on. Equilibrium crystal structures and mechanics properties of MgSiO3 and (Mg0.75, Fe0.25)SiO3 are determined using first-principles calculations in a series of hydrostatic pressures up to 140 GPa. Seismic wave velocity as a function of pressure is derived from the Voigt-Reuss-Hill scheme. Their thermodynamic quantities under the conditions of the lower mantle’s pressures and temperatures are computed by means of the Debye model within the quasi-harmonic approximation. The substitution effect of Fe2+on the thermoelastic property for silicate perovskite is discussed. Substitution of Fe2+for Mg2+can provoke softening wave velocity phenomenon arising from the minerals containing Mg element located in the earth interior. The present theoretical results are useful for interpreting seismic wave velocity softened in certain areas of the mantle.

  4. EDITORIAL: Focus on Nanostructured Soft Matter

    Science.gov (United States)

    Reineker, Peter; Schülz, Michael

    2004-01-01

    Nanostructures in general are playing a more and more important role in the physics and chemistry of condensed matter systems including both hard and soft materials. This Focus Issue concentrates particularly on recent developments in Nanostructured Soft Matter Systems. Many interesting questions related to both fundamental and applied research in this field have arisen. Some of them are connected to the chemical reactions that take place during the irreversible formation of soft matter systems. Others refer to the theoretical and experimental investigations of structures and topologies of `nanostructured soft matter', e.g. heterogeneous polymers and polymer networks, or soft matter at low dimensions or in constrained geometries. Additional research has also been devoted to the dynamics of other complex nanostructured systems, such as the structure formation on the basis of polymer systems and polyelectrolytes, and several kinds of phase transitions on nano- and microscales. The contributions collected here present the most up-to-date research results on all of these topics. New Journal of Physics, as an electronic journal, is perfectly suited for the presentation of the complex results that the experimental and theoretical investigations reported here yield. The articles that will follow provide a number of excellent examples of the use of animations, movies and colour features for the added benefit of the reader. Focus on Nanostructured Soft Matter Contents Phase separation kinetics in compressible polymer solutions: computer simulation of the early stages Peter Virnau, Marcus Müller, Luis González MacDowell and Kurt Binder Spectral dynamics in the B800 band of LH2 from Rhodospirillum molischianum: a single-molecule study Clemens Hofmann, Thijs J Aartsma, Hartmut Michel and Jürgen Köhler Adsorption of polyacrylic acid on self-assembled monolayers investigated by single-molecule force spectroscopy Claudia Friedsam, Aránzazu Del Campo Bécares, Ulrich Jonas

  5. Nuclear Fusion Award 2010 speech Nuclear Fusion Award 2010 speech

    Science.gov (United States)

    Rice, John

    2011-01-01

    Alex Ince-Cushman, John deGrassie, Lars-Goran Eriksson, Yoshiteru Sakamoto, Andrea Scarabosio and Yuri Podpaly, as well as the other coauthors. I would like to express my sincere appreciation to Earl Marmar, Martin Greenwald and Miklos Porkolab at MIT for continued support of this work, as well as to the entire C-Mod team. This award was made possible due to the insight of Mitsuru Kikuchi and the support of the IAEA through Werner Burkhart, and I am truly grateful to both of them. Many thanks as well to the outstanding staff at Nuclear Fusion. It is a distinct honor to be included in the group of previous winners: Tim Luce, Clemente Angioni, Todd Evans and Steve Sabbagh. It is also a great honor to be considered alongside the 2010 nominees: Phil Snyder, Sibylle Guenter, Maiko Yoshida, Hajime Urano, Fulvio Zonca, Erik Garcia, Costanza Maggi, Hartmut Zohm, Thierry Loarer and Bruce Lipschultz. Finally, I would like to thank the readers of Nuclear Fusion for the many citations. John Rice 2010 Nuclear Fusion Award winner Plasma Science and Fusion Center, MIT, Cambridge, MA, USA

  6. The ESO UVES Advanced Data Products Quasar Sample - VI. Sub-Damped Lyman-$\\alpha$ Metallicity Measurements and the Circum-Galactic Medium

    CERN Document Server

    Quiret, S; Zafar, T; Kulkarni, V P; Jenkins, E D; Milliard, B; Rahmani, H; Popping, A; Sandhya, R M; Turnshek, D A; Monier, E M

    2016-01-01

    The Circum-Galactic Medium (CGM) can be probed through the analysis of absorbing systems in the line-of-sight to bright background quasars. We present measurements of the metallicity of a new sample of 15 sub-damped Lyman-$\\alpha$ absorbers (sub-DLAs, defined as absorbers with 19.0 < log N(H I) < 20.3) with redshift 0.584 < $\\rm z_{abs}$ < 3.104 from the ESO Ultra-Violet Echelle Spectrograph (UVES) Advanced Data Products Quasar Sample (EUADP). We combine these results with other measurements from the literature to produce a compilation of metallicity measurements for 92 sub-DLAs as well as a sample of 362 DLAs. We apply a multi-element analysis to quantify the amount of dust in these two classes of systems. We find that either the element depletion patterns in these systems differ from the Galactic depletion patterns or they have a different nucleosynthetic history than our own Galaxy. We propose a new method to derive the velocity width of absorption profiles, using the modeled Voigt profile feat...

  7. Nonlinear electroelastic vibration analysis of NEMS consisting of double-viscoelastic nanoplates

    Science.gov (United States)

    Ebrahimy, Farzad; Hosseini, S. Hamed S.

    2016-10-01

    The nonlinear electroelastic vibration behavior of viscoelastic nanoplates is investigated based on nonlocal elasticity theory. Employing nonlinear strain-displacement relations, the geometrical nonlinearity is modeled while governing equations are derived through Hamilton's principle and they are solved applying semi-analytical generalized differential quadrature (GDQ) method. Eringen's nonlocal elasticity theory takes into account the effect of small size, which enables the present model to become effective in the analysis and design of nanosensors and nanoactuators. Based on Kelvin-Voigt model, the influence of the viscoelastic coefficient is also discussed. It is demonstrated that the GDQ method has high precision and computational efficiency in the vibration analysis of viscoelastic nanoplates. The good agreement between the results of this article and those available in literature validated the presented approach. The detailed mathematical derivations are presented and numerical investigations are performed while the emphasis is placed on investigating the effect of the several parameters such as electric voltage, small-scale effects, van der Waals interaction, Winkler and Pasternak elastic coefficients, the viscidity and aspect ratio of the nanoplate on its nonlinear vibrational characteristics. It is explicitly shown that the electroelastic vibration behavior of viscoelastic nanoplates is significantly influenced by these effects. Numerical results are presented to serve as benchmarks for future analyses of viscoelastic nanoplates which are fundamental elements in nanoelectromechanical systems.

  8. Study on the relationships between Raman shifts and temperature range for a-plane GaN using temperature-dependent Raman scattering

    Institute of Scientific and Technical Information of China (English)

    Wang Dang-Hui; Xu Sheng-Rui; Hao Yue; Zhang Jin-Cheng; Xu Tian-Han; Lin Zhi-Yu; Zhou Hao

    2013-01-01

    In this paper,Raman shifts of a-plane GaN layers grown on r-plane sapphire substrates by low-pressure metal-organic chemical vapor deposition (LPMOCVD) are investigated.We compare the crystal qualities and study the relationships between Raman shift and temperature for conventional a-plane GaN epilayer and insertion A1N/A1GaN superlattice layers for a-plane GaN epilayer using temperature-dependent Raman scattering in a temperature range from 83 K to 503 K.The temperature-dependences of GaN phonon modes (A1 (TO),E2 (high),and E1 (TO)) and the linewidths of E2 (high) phonon peak are studied.The results indicate that there exist two mechanisms between phonon peaks in the whole temperature range,and the relationship can be fitted to the pseudo-Voigt function.From analytic results we find a critical temperature existing in the relationship,which can characterize the anharmonic effects of a-plane GaN in different temperature ranges.In the range of higher temperature,the relationship exhibits an approximately linear behavior,which is consistent with the analyzed results theoretically.

  9. The Effect of AGN Heating on the Low-redshift Lyα Forest

    Science.gov (United States)

    Gurvich, Alex; Burkhart, Blakesley; Bird, Simeon

    2017-02-01

    We investigate the effects of AGN heating and the ultraviolet background on the low-redshift Lyα forest column density distribution (CDD) using the Illustris simulation. We show that Illustris reproduces observations at z = 0.1 in the column density range {10}12.5{--}{10}13.5 cm‑2, relevant for the “photon underproduction crisis.” We attribute this to the inclusion of AGN feedback, which changes the gas distribution so as to mimic the effect of extra photons, as well as the use of the Faucher-Giguère ultraviolet background, which is more ionizing at z = 0.1 than the Haardt & Madau background previously considered. We show that the difference between simulations run with smoothed particle hydrodynamics and simulations using a moving mesh is small in this column density range but can be more significant at larger column densities. We further consider the effect of supernova feedback, Voigt profile fitting, and finite resolution, all of which we show to have little influence on the CDD. Finally, we identify a discrepancy between our simulations and observations at column densities {10}14{--}{10}16 cm‑2, where Illustris produces too few absorbers, which suggests the AGN feedback model should be further refined. Since the “photon underproduction crisis” primarily affects lower column density systems, we conclude that AGN feedback and standard ionizing background models can resolve the crisis.

  10. The analysis of thermoplastic characteristics of special polymer sulfur composite

    Science.gov (United States)

    Książek, Mariusz

    2017-01-01

    Specific chemical environments step out in the industry objects. Portland cement composites (concrete and mortar) were impregnated by using the special polymerized sulfur and technical soot as a filler (polymer sulfur composite). Sulfur and technical soot was applied as the industrial waste. Portland cement composites were made of the same aggregate, cement and water. The process of special polymer sulfur composite applied as the industrial waste is a thermal treatment process in the temperature of about 150-155°C. The result of such treatment is special polymer sulfur composite in a liquid state. This paper presents the plastic constants and coefficients of thermal expansion of special polymer sulfur composites, with isotropic porous matrix, reinforced by disoriented ellipsoidal inclusions with orthotropic symmetry of the thermoplastic properties. The investigations are based on the stochastic differential equations of solid mechanics. A model and algorithm for calculating the effective characteristics of special polymer sulfur composites are suggested. The effective thermoplastic characteristics of special polymer sulfur composites, with disoriented ellipsoidal inclusions, are calculated in two stages: First, the properties of materials with oriented inclusions are determined, and then effective constants of a composite with disoriented inclusions are determined on the basis of the Voigt or Rice scheme. A brief summary of new products related to special polymer sulfur composites is given as follows: Impregnation, repair, overlays and precast polymer concrete will be presented. Special polymer sulfur as polymer coating impregnation, which has received little attention in recent years, currently has some very interesting applications.

  11. Performance-based placement of manufactured viscoelastic dampers for design response spectrum

    Directory of Open Access Journals (Sweden)

    Yutaka eNakamura

    2016-05-01

    Full Text Available In this study, a viscoelastic damper (VED is developed by using a VE material with low temperature dependence, and a performance-based placement-design procedure of VEDs is developed for finding the storywise distribution of VEDs in a building such that each peak interstory drift coincides with the prescribed value. The mechanical properties of the employed VED’s dependence on amplitude and frequency of the excitation as well as material temperature are taken into account and a mechanical nonlinear four-element model that comprises two dashpot elements and two spring elements is proposed for the VED. The developed performance-based design procedure utilizes equivalent linearization of the VED and the expanded complete quadratic combination (CQC method, which involves modal analysis with complex eigenvalue analysis. An equivalent linear Voigt model of the VED is determined by the prescribed peak interstory drift and the fundamental natural period of the structure for which the VEDs are installed. Seismic response analyses are carried out for high-rise building models installed with the necessary number of wall-type VEDs, with the results demonstrating the effectiveness and validity of the proposed performance-based placement-design procedure.

  12. Optimized OpenCL implementation of the Elastodynamic Finite Integration Technique for viscoelastic media

    Science.gov (United States)

    Molero-Armenta, M.; Iturrarán-Viveros, Ursula; Aparicio, S.; Hernández, M. G.

    2014-10-01

    Development of parallel codes that are both scalable and portable for different processor architectures is a challenging task. To overcome this limitation we investigate the acceleration of the Elastodynamic Finite Integration Technique (EFIT) to model 2-D wave propagation in viscoelastic media by using modern parallel computing devices (PCDs), such as multi-core CPUs (central processing units) and GPUs (graphics processing units). For that purpose we choose the industry open standard Open Computing Language (OpenCL) and an open-source toolkit called PyOpenCL. The implementation is platform independent and can be used on AMD or NVIDIA GPUs as well as classical multi-core CPUs. The code is based on the Kelvin-Voigt mechanical model which has the gain of not requiring additional field variables. OpenCL performance can be in principle, improved once one can eliminate global memory access latency by using local memory. Our main contribution is the implementation of local memory and an analysis of performance of the local versus the global memory using eight different computing devices (including Kepler, one of the fastest and most efficient high performance computing technology) with various operating systems. The full implementation of the code is included.

  13. Analysis of magneto-optical properties for three-dimensional photonic crystals in high-symmetry arrangement doped by metamaterials and uniaxial materials

    Science.gov (United States)

    Yu, Bing; Li, Heming; Wang, Shenyun; Wan, Fayu; Ge, Junxiang

    2016-11-01

    In this paper, we use a modified plane wave expansion (PWE) method to investigate the properties of photonic band gaps (PBGs) for the extraordinary mode in the three-dimensional (3D) photonic crystals (PCs) which are composed of the anisotropic dielectric (the uniaxial materials) spheres immersed in the homogeneous metamaterials (epsilon-negative materials) background with high-symmetry (body-centered-cubic) lattices, as the magneto-optical Voigt effects are considered. The equations for calculating the PBGs in the first irreducible Brillouin zone are theoretically derived. It is numerically illustrated that the anisotropic PBGs and two flattened band regions can be achieved. The influences of the ordinary-refractive index, extraordinary-refractive index, filling factor of dielectric spheres, electronic plasma frequency and cyclotron frequency on the magneto-optical properties of such 3D PCs also are studied in detail, respectively, and some corresponding physical explanations are given. The numerical results demonstrate that the anisotropy can open partial band gaps in the proposed PCs, and the complete PBGs can be obtained compared with the conventional PCs only containing the isotropic material with similar structures. The bandwidths of PBGs can be tuned by introducing the epsilon-negative materials into such PCs containing the uniaxial materials. The anisotropic PBGs can be manipulated by the parameters as mentioned above. As the proposed PCs with high-symmetry lattices, the complete PBGs can be obtained by introducing the uniaxial materials.

  14. Application of a spring-dashpot system to clinical lung tumor motion data

    CERN Document Server

    Ackerley, E J; Wilson, P L; Berbeco, R I; Meyer, J

    2012-01-01

    A spring-dashpot system based on the Voigt model was developed to model the correlation between abdominal respiratory motion and tumor motion during lung radiotherapy. The model was applied to clinical data comprising 52 treatment beams from 10 patients, treated on the Mitsubishi Real-Time Radiation Therapy system, Sapporo, Japan. In Stage 1, model parameters were optimized for individual patients and beams to determine reference values and to investigate how well the model can describe the data. In Stage 2, for each patient the optimal parameters determined for a single beam were applied to data from other beams to investigate whether a beam-specific set of model parameters is sufficient to model tumor motion over a course of treatment. In Stage 1 the baseline root mean square (RMS) residual error for all individually-optimized beam data was 0.90 plus or minus 0.40 mm. In Stage 2, patient-specific model parameters based on a single beam were found to model the tumor position closely, even for irregular beam ...

  15. A study of the circum-galactic medium at z ~ 0.6 using DLA-galaxies

    CERN Document Server

    Rahmani, Hadi; Turnshek, David A; Rao, Sandhya M; Quiret, Samuel; Hamilton, Timothy S; Kulkarni, Varsha P; Monier, Eric M

    2016-01-01

    We present the study of a sample of nine QSO fields, with damped-Ly-alpha (DLA) or sub-DLA systems at z~0.6, observed with the X-Shooter spectrograph at the Very Large Telescope. By suitably positioning the X-Shooter slit based on high spatial resolution images of HST/ACS we are able to detect absorbing galaxies in 7 out of 9 fields (~ 78\\% success rate) at impact parameters from 10 to 30 kpc. In 5 out of 7 fields the absorbing galaxies are confirmed via detection of multiple emission lines at the redshift of DLAs where only 1 out of 5 also emits a faint continuum. In 2 out of these 5 fields we detect a second galaxy at the DLA redshift. Extinction corrected star formation rates (SFR) of these DLA-galaxies, estimated using their H-alpha fluxes, are in the range 0.3-6.7 M_sun yr^-1. The emission metallicities of these five DLA-galaxies are estimated to be from 0.2 to 0.9 Z_sun. Based on the Voigt profile fits to absorption lines we find the metallicity of the absorbing neutral gas to be in a range of 0.05--0.6...

  16. Observation of Mollow Triplets with Tunable Interactions in Double Lambda Systems of Individual Hole Spins

    Science.gov (United States)

    Lagoudakis, K. G.; Fischer, K. A.; Sarmiento, T.; McMahon, P. L.; Radulaski, M.; Zhang, J. L.; Kelaita, Y.; Dory, C.; Müller, K.; Vučković, J.

    2017-01-01

    Although individual spins in quantum dots have been studied extensively as qubits, their investigation under strong resonant driving in the scope of accessing Mollow physics is still an open question. Here, we have grown high quality positively charged quantum dots embedded in a planar microcavity that enable enhanced light-matter interactions. Under a strong magnetic field in the Voigt configuration, individual positively charged quantum dots provide a double lambda level structure. Using a combination of above-band and resonant excitation, we observe the formation of Mollow triplets on all optical transitions. We find that when the strong resonant drive power is used to tune the Mollow-triplet lines through each other, we observe anticrossings. We also demonstrate that the interaction that gives rise to the anticrossings can be controlled in strength by tuning the polarization of the resonant laser drive. Quantum-optical modeling of our system fully captures the experimentally observed spectra and provides insight on the complicated level structure that results from the strong driving of the double lambda system.

  17. Pressure broadening, -shift, speed dependence and line mixing in the ν3 rovibrational band of N2O

    Science.gov (United States)

    Loos, Joep; Birk, Manfred; Wagner, Georg

    2015-01-01

    In this paper, we report measured air-broadening, -shift, speed dependence and Rosenkranz line mixing parameters for the ν3 fundamental rovibrational band of N2O. A Bruker IFS 125HR Fourier transform spectrometer was used with a White-type multipass absorption cell with 46.4 m absorption path length to measure four ambient temperature air-broadened absorption spectra at total pressures ranging from 100 to 1000 mbar. A multispectrum fitting technique was used to retrieve parameters up to |m|=40 (m=-J″ and m=J″+1 for the P and R branch, respectively) utilizing the partially correlated quadratic speed-dependent hard collision model including Rosenkranz line mixing. Speed dependence of the broadening parameter as well as line mixing could be observed in the spectra. The broadening parameters are compared to HITRAN2012, where deviations can be ascribed to the influence of neglecting speed dependence effects in spectra analyses when using the Voigt line profile. The line mixing coefficients show a smooth dependence on m.

  18. A computational method to help identify and measure metal lines in high resolution QSO spectra

    Institute of Scientific and Technical Information of China (English)

    Xi-Heng Shi; David Tytler; Jin-Liang Hou; David Kirkman; Jeffery Lee; Benjamin Ou

    2011-01-01

    A computational code is developed to help identify metal absorption lines in high resolution QSO spectra,especially in the Lyα forest.The input to the code includes a list of line central wavelengths,column densities and Doppler widths.The code then searches for candidate metal absorption systems and assesses the probability that each system could be real.The framework of the strategy we employ is described in detail and we discuss how to estimate the errors in line profile fitting that are essential to identification.A series of artificial spectra is constructed to calibrate the performance of the code.Due to the effects of blending and noise on Voigt profile fitting,the completeness of the identification depends on the column density of absorbers.For intermediate and strong artificial metal absorbers,more than 90% could be confirmed by the code.The results of applying the code to the real spectra of QSOs HS0757+5218 and Q0100+1300 are also presented.

  19. Vertical Dynamic Response of Pile Embedded in Layered Transversely Isotropic Soil

    Directory of Open Access Journals (Sweden)

    Wenbing Wu

    2014-01-01

    Full Text Available The dynamic response of pile embedded in layered transversely isotropic soil and subjected to arbitrary vertical harmonic force is investigated. Based on the viscoelastic constitutive relations for a transversely isotropic medium, the dynamic governing equation of the transversely isotropic soil is obtained in cylindrical coordinates. By introducing the fictitious soil pile model and the distributed Voigt model, the governing equations of soil-pile system are also derived. Firstly, the vertical response of the soil layer is solved by using the Laplace transform technique and the separation of variables technique. Secondly, the analytical solution of velocity response in the frequency domain and its corresponding semianalytical solution of velocity response in the time domain are derived by means of inverse Fourier transform and convolution theorem. Finally, based on the obtained solutions, a parametric study has been conducted to investigate the influence of the soil anisotropy on the vertical dynamic response of pile. It can be seen that the influence of the shear modulus of soil in the vertical plane on the dynamic response of pile is more notable than the influence of the shear modulus of soil in the horizontal plane on the dynamic response of pile.

  20. Line-of-Sight Observables Algorithms for the Helioseismic and Magnetic Imager (HMI) Instrument Tested with Interferometric Bidimensional Spectrometer (IBIS) Observations

    Science.gov (United States)

    Couvidat, Sébastien; Rajaguru, S. P.; Wachter, Richard; Sankarasubramanian, K.; Schou, Jesper; Scherrer, Philip H.

    2012-05-01

    The Helioseismic and Magnetic Imager (HMI) instrument onboard the Solar Dynamics Observatory produces line-of-sight (LOS) observables (Doppler velocity, magnetic-field strength, Fe i line width, line depth, and continuum intensity) as well as vector magnetic-field maps at the solar surface. The accuracy of LOS observables is dependent on the algorithm used to translate a sequence of HMI filtergrams into the corresponding observables. Using one hour of high-cadence imaging spectropolarimetric observations of a sunspot in the Fe i line at 6173 Å through the Interferometric Bidimensional Spectrometer installed at the Dunn Solar Telescope, and the Milne-Eddington inversion of the corresponding Stokes vectors, we test the accuracy of the observables algorithm currently implemented in the HMI data-analysis pipeline: the MDI-like algorithm. In an attempt to improve the accuracy of HMI observables, we also compare this algorithm to others that may be implemented in the future: a least-squares fit with a Gaussian profile, a least-squares fit with a Voigt profile, and the use of second Fourier coefficients in the MDI-like algorithm.

  1. Indices of zooplankton community as valuable tools in assessing the trophic state and water quality of eutrophic lakes: long term study of Lake Võrtsjärv

    Directory of Open Access Journals (Sweden)

    Juta Haberman

    2014-03-01

    Full Text Available On the basis of long-term (1964-2011 research, we tested the hypothesis that the zooplankton community has a highly indicative value in assessing the ecosystem and trophic state of water bodies. Basing on the results of our study and taking into account relevant data from numerous zooplankton studies, we can conclude that the zooplankton measures deserving to be used as indicators in the monitoring of Lake Võrtsjärv (and other similar eutrophic water bodies could be the following: i indicatory species of eutrophic waters [Anuraeopsis fissa (Gosse, Keratella tecta (Gosse, Trichocerca rousseleti (Voigt, Chydorus sphaericus (O. F. Müller, Bosmina longirostris (O. F. Müller]; ii indicatory species of oligo-mesotrophic waters [Conochilus unicornis Rousselet, Kellicottia longispina (Kellicott, Ploesoma hudsoni (Imhof, Bosmina berolinensis Imhof, Eudiaptomus gracilis (Sars]; iii number and diversity of species; iv mean zooplankter weight, mean cladoceran weight, mean rotifer weight and mean copepod weight; v rotifer abundance; vi the share (% of rotifers in total zooplankton abundance; vii the ratio of abundance of large cladocerans to abundance of all cladocerans (NLargeClad/NClad; viii the ratio of calanoid copepod abundance to cyclopoid copepod abundance (NCal/NCycl; ix the ratio of crustacean abundance to rotifer abundance (NCrust/NRot . The results of our study show that several zooplankton parameters are among the biological quality elements (BQE deserving to be included in the Water Frame Directive system.

  2. Small angle X-ray scattering study of poly(N-isopropyl acrylamide) based cryogels near the volume-phase transition temperature

    Energy Technology Data Exchange (ETDEWEB)

    Chalal, Mohand [Laboratoire d' Electronique Quantique, Faculte de Physique, USTHB Alger, 16111 Alger (Algeria); Ehrburger-Dolle, Francoise; Morfin, Isabelle [Laboratoire de Spectrometrie Physique, UMR 5588 CNRS/UJF, 38402 Saint Martin d' Heres (France); Armas, Maria-Rosa Aguilar de; Lopez, Maria-Luisa [Instituto de Ciencia y TecnologIa de PolImeros, CSIC and CIBER-BBN, 28006 Madrid (Spain); Bley, Francoise, E-mail: francoise.ehrburger-dolle@ujf-grenoble.f [Science et Ingenierie des Materiaux et Procedes, UMR 5266 CNRS/INPG/UJF, 38402 Saint Martin d' Heres (France)

    2010-10-01

    The structural modifications induced by changes in temperature are investigated by Small-Angle X-ray Scattering (SAXS) over a broad range of q-values (3.5x10{sup -2} - 12 nm{sup -1}) in cryogels based on N-isopropylacrylamide (NIPA) and/or 2-Hydroxyethyl methacrylate-L-Lactide-Dextran (HEMA-LLA-D) macromer. Various copolymeric cryogels of these two monomers are prepared by cryopolymerization yielding macroporous gels (cryogels). For the plain pNIPA cryogel, the SAXS curves obtained at each temperature are well fitted by a sum of four equations describing respectively the scattering resulting from the gel surface (power law), from the solid-like (Guinier equation) and liquid-like (Ornstein-Zernike equation) heterogeneities and from the chain-chain correlation yielding a broad peak (pseudo-Voigt equation) in the high-q domain. The temperature dependence of the parameters obtained from the fit is analyzed and discussed. It is shown that the existence of an isoscattering (or isosbestic) point observed in pNIPA gels and in some copolymers is related to features observed by Differential Scanning Calorimetry and swelling ratio measurements.

  3. Accurate lineshape spectroscopy and the Boltzmann constant.

    Science.gov (United States)

    Truong, G-W; Anstie, J D; May, E F; Stace, T M; Luiten, A N

    2015-10-14

    Spectroscopy has an illustrious history delivering serendipitous discoveries and providing a stringent testbed for new physical predictions, including applications from trace materials detection, to understanding the atmospheres of stars and planets, and even constraining cosmological models. Reaching fundamental-noise limits permits optimal extraction of spectroscopic information from an absorption measurement. Here, we demonstrate a quantum-limited spectrometer that delivers high-precision measurements of the absorption lineshape. These measurements yield a very accurate measurement of the excited-state (6P1/2) hyperfine splitting in Cs, and reveals a breakdown in the well-known Voigt spectral profile. We develop a theoretical model that accounts for this breakdown, explaining the observations to within the shot-noise limit. Our model enables us to infer the thermal velocity dispersion of the Cs vapour with an uncertainty of 35 p.p.m. within an hour. This allows us to determine a value for Boltzmann's constant with a precision of 6 p.p.m., and an uncertainty of 71 p.p.m.

  4. Defect structure of epitaxial layers of III nitrides as determined by analyzing the shape of X-ray diffraction peaks

    Science.gov (United States)

    Kyutt, R. T.

    2017-04-01

    The shape of X-ray diffraction epitaxial layers with high dislocation densities has been studied experimentally. Measurements with an X-ray diffractometer were performed in double- and triple-crystal setups with both Cu K α and Mo K α radiation. Epitaxial layers (GaN, AlN, AlGaN, ZnO, etc.) with different degrees of structural perfection grown by various methods on sapphire, silicon, and silicon carbide substrates have been examined. The layer thickness varied in the range of 0.5-30 μm. It has been found that the center part of peaks is well approximated by the Voigt function with different Lorentz fractions, while the wing intensity drops faster and may be represented by a power function (with the index that varies from one structure to another). A well-marked dependence on the ordering of dislocations was observed. The drop in intensity in the majority of structures with a regular system and regular threading dislocations was close to the theoretically predicted law Δθ-3; the intensity in films with a chaotic distribution decreased much faster. The dependence of the peak shape on the order of reflection, the diffraction geometry, and the epitaxial layer thickness was also examined.

  5. Suppression of shocked-bubble expansion due to tissue confinement with application to shock-wave lithotripsy.

    Science.gov (United States)

    Freund, Jonathan B

    2008-05-01

    Estimates are made of the effect of tissue confinement on the response of small bubbles subjected to lithotriptor shock pressures. To do this the Rayleigh-Plesset equation, which governs the dynamics of spherical bubbles, is generalized to treat a bubble in a liquid region (blood), which is in turn encased within an elastic membrane (like a vessel's basement membrane), beyond which a Voigt viscoelastic material models the exterior tissue. Material properties are estimated from a range of measurements available for kidneys and similar soft tissues. Special attention is given to the constitutive modeling of the basement membranes because of their expected importance due to their proximity to the bubble and their toughness. It is found that the highest expected values for the elasticity of the membrane and surrounding tissue are insufficient to suppress bubble growth. The reduced confinement of a cylindrical vessel should not alter this conclusion. Tissue viscosities taken from ultrasound measurements suppress bubble growth somewhat, though not to a degree expected to resist injury. However, the higher reported viscosities measured by other means, which are arguably more relevant to the deformations caused by growing bubbles, do indeed significantly suppress bubble expansion.

  6. Numerical modeling of bubble dynamics in viscoelastic media with relaxation

    Science.gov (United States)

    Warnez, M. T.; Johnsen, E.

    2015-06-01

    Cavitation occurs in a variety of non-Newtonian fluids and viscoelastic materials. The large-amplitude volumetric oscillations of cavitation bubbles give rise to high temperatures and pressures at collapse, as well as induce large and rapid deformation of the surroundings. In this work, we develop a comprehensive numerical framework for spherical bubble dynamics in isotropic media obeying a wide range of viscoelastic constitutive relationships. Our numerical approach solves the compressible Keller-Miksis equation with full thermal effects (inside and outside the bubble) when coupled to a highly generalized constitutive relationship (which allows Newtonian, Kelvin-Voigt, Zener, linear Maxwell, upper-convected Maxwell, Jeffreys, Oldroyd-B, Giesekus, and Phan-Thien-Tanner models). For the latter two models, partial differential equations (PDEs) must be solved in the surrounding medium; for the remaining models, we show that the PDEs can be reduced to ordinary differential equations. To solve the general constitutive PDEs, we present a Chebyshev spectral collocation method, which is robust even for violent collapse. Combining this numerical approach with theoretical analysis, we simulate bubble dynamics in various viscoelastic media to determine the impact of relaxation time, a constitutive parameter, on the associated physics. Relaxation time is found to increase bubble growth and permit rebounds driven purely by residual stresses in the surroundings. Different regimes of oscillations occur depending on the relaxation time.

  7. Ion-beam modifications of mechanical and dimensional properties of silicon carbide

    Science.gov (United States)

    Costantini, Jean-Marc; Kerbiriou, Xavier; Sauzay, Maxime; Thomé, Lionel

    2012-11-01

    3C-SiC single crystal epitaxial layers, 6H-SiC single crystal plates and α-SiC Hexoloy sinters were irradiated with 4.0 MeV Xe or 4.0 MeV Au ions at room temperature. Mechanical and dimensional evolutions of silicon carbide are studied by means of nano-indentation and step-height measurements which are correlated with Rutherford backscattering spectrometry and channelling (RBS/C) data in single crystals. Irradiation with Xe ions induces a total lattice disorder related to amorphization for a fluence of 1 × 1015 cm-2 in both polytypes. When complete amorphization is reached, around the same values of Young's modulus (˜350 GPa) and Berkovich hardness (˜27 GPa) are found in both polytypes. The out-of-plane expansion increases with irradiation dose and the saturation value measured in the amorphous layer (normalized to the projected range of the ions) is close to 20-25%. Modifications of macroscopic properties are mainly governed by the disordered fraction of the material in a two-step damage process. A similar behaviour of material evolution is found for the cubic and hexagonal polytypes, either in single crystals or sintered polycrystalline samples. Calculations of Young's modulus and volume swelling are carried out using the analytical (Reuss and Voigt) models of homogenization.

  8. Multispectrum Analysis of the Oxygen A-Band

    Energy Technology Data Exchange (ETDEWEB)

    Drouin, Brian J.; Benner, D. Chris; Brown, Linda R.; Cich, Matthew J.; Crawford, Timothy J.; Devi, V. Malathy; Guillaume, Alexander; Hodges, Joseph T.; Mlawer, Eli J.; Robichaud, David J.; Oyafuso, Fabiano; Payne, Vivienne H.; Sung, Keeyoon; Wishnow, Edward H.; Yu, Shanshan

    2017-01-01

    Retrievals of atmospheric composition from near-infrared measurements require measurements of airmass to better than the desired precision of the composition. The oxygen bands are obvious choices to quantify airmass since the mixing ratio of oxygen is fixed over the full range of atmospheric conditions. The OCO-2 mission is currently retrieving carbon dioxide concentration using the oxygen A-band for airmass normalization. The 0.25% accuracy desired for the carbon dioxide concentration has pushed the required state-of-the-art for oxygen spectroscopy. To measure O2 A-band cross-sections with such accuracy through the full range of atmospheric pressure requires a sophisticated line-shape model (Rautian or Speed-Dependent Voigt) with line mixing (LM) and collision induced absorption (CIA). Models of each of these phenomena exist, however, this work presents an integrated self-consistent model developed to ensure the best accuracy. It is also important to consider multiple sources of spectroscopic data for such a study in order to improve the dynamic range of the model and to minimize effects of instrumentation and associated systematic errors. The techniques of Fourier Transform Spectroscopy (FTS) and Cavity Ring-Down Spectroscopy (CRDS) allow complimentary information for such an analysis. We utilize multispectrum fitting software to generate a comprehensive new database with improved accuracy based on these datasets. The extensive information will be made available as a multi-dimensional cross-section (ABSCO) table and the parameterization will be offered for inclusion in the HITRANonline database.

  9. Quantitative Analysis of Spectral Interference of Spontaneous Raman Scattering in High-Pressure Fuel-Rich H2-Air Combustion

    Science.gov (United States)

    Kojima, Jun; Nguyen, Quang-Viet

    2004-01-01

    We present a theoretical study of the spectral interferences in the spontaneous Raman scattering spectra of major combustion products in 30-atm fuel-rich hydrogen-air flames. An effective methodology is introduced to choose an appropriate line-shape model for simulating Raman spectra in high-pressure combustion environments. The Voigt profile with the additive approximation assumption was found to provide a reasonable model of the spectral line shape for the present analysis. The rotational/vibrational Raman spectra of H2, N2, and H2O were calculated using an anharmonic-oscillator model using the latest collisional broadening coefficients. The calculated spectra were validated with data obtained in a 10-atm fuel-rich H2-air flame and showed excellent agreement. Our quantitative spectral analysis for equivalence ratios ranging from 1.5 to 5.0 revealed substantial amounts of spectral cross-talk between the rotational H2 lines and the N2 O-/Q-branch; and between the vibrational H2O(0,3) line and the vibrational H2O spectrum. We also address the temperature dependence of the spectral cross-talk and extend our analysis to include a cross-talk compensation technique that removes the nterference arising from the H2 Raman spectra onto the N2, or H2O spectra.

  10. Carbohydrate-Derived Amphiphilic Macromolecules: A Biophysical Structural Characterization and Analysis of Binding Behaviors to Model Membranes

    Science.gov (United States)

    Martin, Adriana A. T.; Tomasini, Michael; Kholodovych, Vladyslav; Gu, Li; Sommerfeld, Sven Daniel; Uhrich, Kathryn E.; Murthy, N. Sanjeeva; Welsh, William J.; Moghe, Prabhas V.

    2015-01-01

    The design and synthesis of enhanced membrane-intercalating biomaterials for drug delivery or vascular membrane targeting is currently challenged by the lack of screening and prediction tools. The present work demonstrates the generation of a Quantitative Structural Activity Relationship model (QSAR) to make a priori predictions. Amphiphilic macromolecules (AMs) “stealth lipids” built on aldaric and uronic acids frameworks attached to poly(ethylene glycol) (PEG) polymer tails were developed to form self-assembling micelles. In the present study, a defined set of novel AM structures were investigated in terms of their binding to lipid membrane bilayers using Quartz Crystal Microbalance with Dissipation (QCM-D) experiments coupled with computational coarse-grained molecular dynamics (CG MD) and all-atom MD (AA MD) simulations. The CG MD simulations capture the insertion dynamics of the AM lipophilic backbones into the lipid bilayer with the PEGylated tail directed into bulk water. QCM-D measurements with Voigt viscoelastic model analysis enabled the quantitation of the mass gain and rate of interaction between the AM and the lipid bilayer surface. Thus, this study yielded insights about variations in the functional activity of AM materials with minute compositional or stereochemical differences based on membrane binding, which has translational potential for transplanting these materials in vivo. More broadly, it demonstrates an integrated computational-experimental approach, which can offer a promising strategy for the in silico design and screening of therapeutic candidate materials. PMID:25855953

  11. Prediction study of the elastic and thermodynamic properties of the newly discovered tetragonal SrPd 2Ge 2 phase

    Science.gov (United States)

    Ghebouli, M. A.; Bouhemadou, A.; Ghebouli, B.; Fatmi, M.; Bin-Omran, S.

    2011-07-01

    Density functional theory pseudo-potential plane-wave calculations are performed in order to predict the structural, elastic and thermodynamic properties of the newly discovered tetragonal intermetallic SrPd 2Ge 2. The computed equilibrium lattice constants and the internal parameter are in good agreement with the experimental findings. The effect of high pressure, up to 40 GPa, on the lattice constants shows that the contraction along the c axis is higher than along the a axis. The single-crystal elastic constants and related properties are calculated using the static finite strain technique. We predicted the bulk modulus, shear modulus, Young's modulus and Poisson's ratio for ideal polycrystalline SrPd 2Ge 2 aggregates, using the Voigt-Reuss-Hill approximations. We estimated the Debye temperature and minimum thermal conductivity of SrPd 2Ge 2 from the average sound velocity. Through the quasi-harmonic Debye model, in which the phononic effects are considered, the temperature and pressure effects on the primitive cell volume, bulk modulus, thermal expansion coefficient, heat capacity and Debye temperature are investigated. This is the first quantitative theoretical prediction of the elastic and thermodynamic properties of the SrPd 2Ge 2 compound, and it still awaits experimental confirmation.

  12. Fractional characteristic times and dissipated energy in fractional linear viscoelasticity

    Science.gov (United States)

    Colinas-Armijo, Natalia; Di Paola, Mario; Pinnola, Francesco P.

    2016-08-01

    In fractional viscoelasticity the stress-strain relation is a differential equation with non-integer operators (derivative or integral). Such constitutive law is able to describe the mechanical behavior of several materials, but when fractional operators appear, the elastic and the viscous contribution are inseparable and the characteristic times (relaxation and retardation time) cannot be defined. This paper aims to provide an approach to separate the elastic and the viscous phase in the fractional stress-strain relation with the aid of an equivalent classical model (Kelvin-Voigt or Maxwell). For such equivalent model the parameters are selected by an optimization procedure. Once the parameters of the equivalent model are defined, characteristic times of fractional viscoelasticity are readily defined as ratio between viscosity and stiffness. In the numerical applications, three kinds of different excitations are considered, that is, harmonic, periodic, and pseudo-stochastic. It is shown that, for any periodic excitation, the equivalent models have some important features: (i) the dissipated energy per cycle at steady-state coincides with the Staverman-Schwarzl formulation of the fractional model, (ii) the elastic and the viscous coefficients of the equivalent model are strictly related to the storage and the loss modulus, respectively.

  13. Sparse Representation of Photometric Redshift PDFs: Preparing for Petascale Astronomy

    CERN Document Server

    Kind, M Carrasco

    2014-01-01

    One of the consequences of entering the era of precision cosmology is the widespread adoption of photometric redshift probability density functions (PDFs). Both current and future photometric surveys are expected to obtain images of billions of distinct galaxies. As a result, storing and analyzing all of these PDFs will be non-trivial and even more severe if a survey plans to compute and store multiple different PDFs. In this paper we propose the use of a sparse basis representation to fully represent individual photo-$z$ PDFs. By using an Orthogonal Matching Pursuit algorithm and a combination of Gaussian and Voigt basis functions, we demonstrate how our approach is superior to a multi-Gaussian fitting, as we require approximately half of the parameters for the same fitting accuracy with the additional advantage that an entire PDF can be stored by using a 4-byte integer per basis function, and we can achieve better accuracy by increasing the number of bases. By using data from the CFHTLenS, we demonstrate th...

  14. ELASTIC PROPERTIES OF SILICA POLYMORPHS – A REVIEW

    Directory of Open Access Journals (Sweden)

    Pabst W.

    2013-09-01

    Full Text Available The elastic properties of silica phases are reviewed. Available monocrystal data for crystalline SiO2 polymorphs (low-quartz, high-quartz, low-cristobalite, high-cristobalite, stishovite are collected from the literature, and effective elastic constants (Young’s moduli, shear moduli, bulk moduli and Poisson ratios are calculated from these using Voigt-Reuss-Hill averaging. Both experimental data and simulation results are taken into account. A table of room temperature elastic constants for crystalline silica polymorphs and silica glass is given that lists the recommended current “state-of-the-art“ values. All data are consistent with the well-known auxetic behavior of cristobalite at room temperature, and high-temperature simulation data published for cristobalite confirm auxetic behavior for all temperatures from room temperature up to more than 1500°C. The calculations of this paper show that also quartz can be auxetic, but only in a very limited temperature range around the low-to-high-quartz transition temperature (420 – 577°C. Experimental measurements of elastic properties of tridymite and cristobalite, including high-temperature measurements, are identified as a desideratum of future research.

  15. Wave propagation analysis of edge cracked circular beams under impact force.

    Directory of Open Access Journals (Sweden)

    Şeref Doğuşcan Akbaş

    Full Text Available This paper presents responses of an edge circular cantilever beam under the effect of an impact force. The beam is excited by a transverse triangular force impulse modulated by a harmonic motion. The Kelvin-Voigt model for the material of the beam is used. The cracked beam is modelled as an assembly of two sub-beams connected through a massless elastic rotational spring. The considered problem is investigated within the Bernoulli-Euler beam theory by using energy based finite element method. The system of equations of motion is derived by using Lagrange's equations. The obtained system of linear differential equations is reduced to a linear algebraic equation system and solved in the time domain by using Newmark average acceleration method. In the study, the effects of the location of crack, the depth of the crack, on the characteristics of the reflected waves are investigated in detail. Also, the positions of the cracks are calculated by using reflected waves.

  16. Residual elastic strain measurement in heat-treated and/or plastically deformed two-phase stainless steel by neutron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Harjo, S.; Sato, Hideo; Tomota, Yo [Ibaraki Univ., Hitachi (Japan). Faculty of Engineering; Ono, Masayoshi

    1997-06-01

    The testing method of microscopic residual stress in commercial material using neutral diffraction is not established yet like that using x-ray diffraction. Then, in this research a microscopic residual stress of {alpha}/{gamma} two phase Fe-Cr-Ni alloy convenient for an experiment was tried by using neutron diffraction, to investigate its testing method. And further, a test using x-ray diffraction was also conducted for their comparison. As a result, some problems in the residual stress measurement using neutron diffraction were summarized shown as follows. On precision of d{sub 0}, since proper reference material was difficult for material M to provide, a preferable result could not be obtained in the stress measurement using PSD method. On curve fitting, by changing from a multi order function to a Voigt function by using the curve-fitting method, it was found that the peak could be fit better. Furthermore, on the problem of testing condition, because of weak intensity of the neutron source, it was necessary to use a monochromator capable of collecting incident beam like Bent crystal, and to improve sample setting, counter and slit. (G.K.)

  17. First line shape analysis and spectroscopic parameters for the ν11 band of 12C2H4

    KAUST Repository

    Es-sebbar, Et-touhami

    2016-08-11

    An accurate knowledge of line intensities, collisional broadening coefficients and narrowing parameters is necessary for the interpretation of high-resolution infrared spectra of the Earth and other planetary atmospheres. One of the most promising spectral domains for (C2H4)-C-12 monitoring in such environments is located near the 336 gm window, through its v(11) C-H stretching mode. In this paper, we report an extensive study in which we precisely determine spectroscopic parameters of (C2H4)-C-12 v(11) band at 297 +/- 1 K, using a narrow Difference-Frequency-Generation (DFG) laser with 10(-4) cm(-1) resolution. Absorption measurements were performed in the 2975-2980 cm(-1) spectral window to investigate 32 lines corresponding to where, J\\'ka\\',kc\\'<- Jka,kc, 5 <= J <= 7; 0.5 <= K-a <= 6 and 1 <= K-c <= 14. Spectroscopic parameters are retrieved using either Voigt or appropriate Galatry profile to simulate the measured (C2H4)-C-12 line shape. Line intensities along with self-broadening coefficients are reported for all lines. Narrowing coefficients for each isolated line are also derived. To our knowledge, the current study reports the first extensive spectroscopic parameter measurements of the (C2H4)-C-12 v(11) band in the 2975-2980 cm(-1) range. (C) 2016 Elsevier Ltd. All rights reserved.

  18. Measurements of NH3 linestrengths and collisional broadening coefficients in N2, O2, CO2, and H2O near 1103.46cm-1

    KAUST Repository

    Owen, Kyle

    2013-05-01

    Laser-based ammonia gas sensors have useful applications in many fields including combustion, atmospheric monitoring, and medical diagnostics. Calibration-free trace gas sensors require the spectroscopic parameters including linestrengths and collisional broadening coefficients to be known. Ammonia\\'s strong ν2 vibrational band between 9 - 12 μm has the high absorption strength needed for sensing small concentrations. Within this band, the 1103.46cm-1 feature is one of the strongest and has minimal interference from CO2 and H2O. However, the six rotational transitions that make up this feature have not been studied previously with absorption spectroscopy due to their small line spacing ranging from 0.004 to 0.029cm-1. A tunable quantum cascade laser was used to accurately study these six transitions. A retrieval program was used to determine the linestrengths and collisional broadening coefficients based on Voigt and Galatry profiles. The experiments were performed with ammonia mixtures in nitrogen, oxygen, water vapor, and carbon dioxide at room temperature in an optical cell. These data are going to aid in the development of quantitative ammonia sensors utilizing this strong absorption feature. © 2013 Elsevier Ltd.

  19. Longitudinal vibration of pile in layered soil based on Rayleigh-Love rod theory and fictitious soil-pile model

    Institute of Scientific and Technical Information of China (English)

    Lü Shu-hui; WANG Kui-hua; WU Wen-bing; C. J. LEO

    2015-01-01

    The dynamic response of pile in layered soil is theoretically investigated when considering the transverse inertia effect. Firstly, the fictitious soil-pile model is employed to simulate the dynamic interaction between the pile and the soil layers beneath pile toe. The dynamic interactions of adjacent soil layers along the vertical direction are simplified as distributed Voigt models. Meanwhile, the pile and fictitious soil-pile are assumed to be viscoelastic Rayleigh-Love rods, and both the radial and vertical displacement continuity conditions at the soil-pile interface are taken into consideration. On this basis, the analytical solution for dynamic response at the pile head is derived in the frequency domain and the corresponding quasi-analytical solution in the time domain is then obtained by means of the convolution theorem. Following this, the accuracy and parameter value of the hypothetical boundaries for soil-layer interfaces are discussed. Comparisons with published solution and measured data are carried out to verify the rationality of the present solution. Parametric analyses are further conducted by using the present solution to investigate the relationships between the transverse inertia effects and soil-pile parameters.

  20. Performance of viscoelastic dampers (VED) under various temperatures and application of magnetorheological dampers (MRD) for seismic control of structures

    Science.gov (United States)

    Bhatti, Abdul Qadir

    2013-08-01

    A number of studies have been carried out to investigate the performance of viscoelastic dampers (VEDs) and magnetorheological dampers (MRDs) in controlling the seismic response of buildings, but very few of them regarding the effect of temperature on the behavior of those dampers. The energy absorption properties of the VEDs are dependent on the ambient temperature, excitation frequency and strain amplitude. Several mathematical models have been investigated for reproducing the experimental behavior of single degree of freedom VEDs and MEDs. Of these, only the fractional derivative model can reflect the influence of temperature which is, however, so complex that it is difficult to apply in structural analysis. In order to verify the effect of temperature, two case studies of structural element have been conducted: once using VED and once using MRD. Kelvin-Voigt mathematical model applied, they were investigated and after analyzing the results, the force vs. displacement showed that MRD achieved a high force capacity and a better performance than VED. Furthermore, the effect of the temperature in case of VED observed via plotting the dissipated energy hysteresis at different temperatures. These results validate the effect of the temperature as the lower the temperature the more viscous the dashpot element becomes, hence improving damping, but this is up to a specific low temperature.

  1. Electromechanical Impedance Response of a Cracked Timoshenko Beam

    Directory of Open Access Journals (Sweden)

    Cuiqin Wu

    2011-07-01

    Full Text Available Typically, the Electromechanical Impedance (EMI technique does not use an analytical model for basic damage identification. However, an accurate model is necessary for getting more information about any damage. In this paper, an EMI model is presented for predicting the electromechanical impedance of a cracked beam structure quantitatively. A coupled system of a cracked Timoshenko beam with a pair of PZT patches bonded on the top and bottom surfaces has been considered, where the bonding layers are assumed as a Kelvin-Voigt material. The shear lag model is introduced to describe the load transfer between the PZT patches and the beam structure. The beam crack is simulated as a massless torsional spring; the dynamic equations of the coupled system are derived, which include the crack information and the inertial forces of both PZT patches and adhesive layers. According to the boundary conditions and continuity conditions, the analytical expression of the admittance of PZT patch is obtained. In the case study, the influences of crack and the inertial forces of PZT patches are analyzed. The results show that: (1 the inertial forces affects significantly in high frequency band; and (2 the use of appropriate frequency range can improve the accuracy of damage identification.

  2. Recommended isolated-line profile for representing high-resolution spectroscopic transitions (IUPAC Technical Report)

    CERN Document Server

    Tennyson, Jonathan; Campargue, Alain; Csaszar, Attila G; Daumont, Ludovic; Gamache, Robert R; Hodges, Joseph T; Lisak, Daniel; Naumenko, Olga V; Rothman, Laurence S; Tran, Ha; Zobov, Nikolai F; Buldyreva, Jeanna; Boone, Chris D; De Vizia, Maria Domenica; Gianfrani, Livio; Hartmann, Jean-Michel; McPheat, Robert; Murray, Jonathan; Ngo, Ngoc Hoa; Polyansky, Oleg L; Weidmann, Damien

    2014-01-01

    The report of an IUPAC Task Group, formed in 2011 on "Intensities and line shapes in high-resolution spectra of water isotopologues from experiment and theory" (Project No. 2011-022-2-100), on line profiles of isolated high-resolution rotational-vibrational transitions perturbed by neutral gas-phase molecules is presented. The well-documented inadequacies of the Voigt profile (VP), used almost universally by databases and radiative-transfer codes, to represent pressure effects and Doppler broadening in isolated vibrational-rotational and pure rotational transitions of the water molecule have resulted in the development of a variety of alternative line-profile models. These models capture more of the physics of the influence of pressure on line shapes but, in general, at the price of greater complexity. The Task Group recommends that the partially Correlated quadratic-Speed-Dependent Hard-Collision profile should be adopted as the appropriate model for high-resolution spectroscopy. For simplicity this should b...

  3. Ab initio study of mechanical and thermo-acoustic properties of tough ceramics: applications to HfO{sub 2} in its cubic and orthorhombic phase

    Energy Technology Data Exchange (ETDEWEB)

    Ponce, C A [Departamento de Fisica, Facultad de Ciencias Exactas, y Naturales y Agrimensura, UNNE, Campus Universitario, Avenida Libertad 5600, CP 3400, Corrientes (Argentina); Casali, R A [Departamento de Fisica, Facultad de Ciencias Exactas, y Naturales y Agrimensura, UNNE, Campus Universitario, Avenida Libertad 5600, CP 3400, Corrientes (Argentina); Caravaca, M A [Departamento de Fisico, Quimica, Facultad de Ingenieria, UNNE, Avenida Las Heras 727, CP 3500, Resistencia (Argentina)

    2008-01-30

    By means of the ab initio all-electron new full-potential linear-muffin-tin orbitals method, calculations were made for elastic constants C{sub 11}, C{sub 12} and C{sub 44} for Si, ZrO{sub 2} and HfO{sub 2} in their cubic phase, and constants C{sub 11}, C{sub 22}, C{sub 33}, C{sub 12}, C{sub 13}, C{sub 23}, C{sub 44}, C{sub 55} and C{sub 66} for HfO{sub 2} in its orthorhombic phase. Using the Voigt and Reuss theory, estimations were made for polycrystals of their bulk, shear and Young moduli, and Poisson coefficients. The speed of elastic wave propagations and Debye temperatures were estimated for polycrystals built from Si and the above mentioned compounds. The semicore 4f{sup 14} electrons should be included in the valence set of Hf atom in this all-electron approach if accurate results for elastic properties under pressures are looked for.

  4. A systematic muscle model covering regions from the fast ramp stretches in the muscle fibres to the relatively slow stretches in the human triceps surae.

    Science.gov (United States)

    Tamura, Youjiro; Ito, Akira; Cresswell, Andrew G

    2015-01-01

    We have proposed a muscle model which consists of two Maxwell elements and a Voigt element in parallel. The muscle model was applied on the experiment of the force responses by the fast ramp stretch in muscle fibres to determine the mechanical parameters. In the simulation, the Maxwell element with a flexible spring and a long relaxation time seemed to correspond with the force-generating state of the cross-bridges. Next, we tried the muscle model to simulate the relatively slow movement. Experimentally, we have measured torque changes by the stretch responses in the human triceps surae. In the experiments, the derivation of torque by rotation angle showed two peaks P1 and P2. The first peak P1 originated from the elastic properties of engaged cross-bridges, while the second peak P2 was due to stretch reflex signals. The model of a single-joint system simulated well with the experimental results to show a good adaptability of the muscle model.

  5. Insight into structural, mechanical, electronic and thermodynamic properties of intermetallic phases in Zr-Sn system from first-principles calculations

    Science.gov (United States)

    Liu, Shuai; Zhan, Yongzhong; Wu, Junyan; Wei, Xuanchen

    2015-11-01

    The structural, phase stabilities, mechanical, electronic and thermodynamic properties of intermetallic phases in Zr-Sn system are investigated by using first-principles method. The equilibrium lattice constants, enthalpy of formation (ΔHform) and elastic constants are obtained and compared with available experimental and theoretical data. The configuration of Zr4Sn is measured with reasonable precision. The ΔHform of five hypothetical structures are obtained in order to find possible metastable phase for Zr-Sn system. The mechanical properties, including bulk modulus, shear modulus, Young's modulus and Poisson's ratio, are calculated by Voigt-Reuss-Hill approximation and the Zr5Sn4 and Zr5Sn3 show excellent mechanical properties. The electronic density of states for Zr5Sn4, Zr5Sn3 and cP8-Zr3Sn are calculated to further investigate the stability of intermetallic compounds. Through the quasi-harmonic Debye model, the Debye temperature, heat capacity and thermal expansion coefficient under temperature of 0-300 K and pressure of 0-50 GPa for Zr5Sn3 and Zr5Sn4 are deeply investigated.

  6. A first-principles study on structural stability and mechanical properties of polar intermetallic phases CaZn2 and SrZn2

    Science.gov (United States)

    Hu, Wen-Cheng; Liu, Yong; Li, De-Jiang; Li, Ke; Jin, Hua-Lan; Xu, Ying-Xuan; Xu, Chun-Shui; Zeng, Xiao-Qin

    2014-12-01

    Structural stability and electronic properties of polar intermetallic CaZn2 and SrZn2 in both CeCu2-type and MgZn2-type structures have been investigated using first-principles method. The calculated equilibrium lattice parameters agree closely with the available experimental and other theoretical results. In terms of formation enthalpy, it is discovered that the present compounds with CeCu2-type structure are energetically more stable than that with MgZn2-type. They are all mechanically stable according to the criteria of elastic stability. In particular, we have investigated the pressure effect on the compressive behaviour and structural stability of each compound. Subsequently, the bulk modulus, shear modulus, Young's modulus, theoretical hardness, Poisson's ratio and Debye temperature in the ground state can be estimated using Voigt-Reuss-Hill homogenization method. Mechanical anisotropy is characterized by the anisotropic factors and direction-dependent Young's modulus. Finally, the electronic structures are determined to reveal the bonding characteristics of considered phases.

  7. Connecting the grain-shearing mechanism of wave propagation in marine sediments to fractional order wave equations.

    Science.gov (United States)

    Pandey, Vikash; Holm, Sverre

    2016-12-01

    The characteristic time-dependent viscosity of the intergranular pore-fluid in Buckingham's grain-shearing (GS) model [Buckingham, J. Acoust. Soc. Am. 108, 2796-2815 (2000)] is identified as the property of rheopecty. The property corresponds to a rare type of a non-Newtonian fluid in rheology which has largely remained unexplored. The material impulse response function from the GS model is found to be similar to the power-law memory kernel which is inherent in the framework of fractional calculus. The compressional wave equation and the shear wave equation derived from the GS model are shown to take the form of the Kelvin-Voigt fractional-derivative wave equation and the fractional diffusion-wave equation, respectively. Therefore, an analogy is drawn between the dispersion relations obtained from the fractional framework and those from the GS model to establish the equivalence of the respective wave equations. Further, a physical interpretation of the characteristic fractional order present in the wave equations is inferred from the GS model. The overall goal is to show that fractional calculus is not just a mathematical framework which can be used to curve-fit the complex behavior of materials. Rather, it can also be derived from real physical processes as illustrated in this work by the example of GS.

  8. Single-crystal elasticity of diaspore, AlOOH, to 12 GPa by Brillouin scattering

    Science.gov (United States)

    Jiang, Fuming; Majzlan, Juraj; Speziale, Sergio; He, Duanwei; Duffy, Thomas S.

    2008-11-01

    The high-pressure elasticity of diaspore (AlOOH) has been determined by Brillouin spectroscopy to 12 GPa in diamond anvil cells. Experiments were carried out using a 16:3:1 methanol-ethanol-water mixture as pressure medium, and ruby as pressure standard. Acoustic velocities were measured in three roughly orthogonal planes at ambient and eight elevated pressures. The nine individual elastic stiffness constants of the orthorhombic crystal were obtained by fitting the velocity data to Christoffel's equation. Aggregate elastic moduli and pressure derivatives were calculated from the Cijs by fits to Eulerian finite strain equations, yielding: K=152(1) GPa, G0 = 117.2(5) GPa, (/∂P)T=3.7(1),   (=1.5(1) for the Voigt-Reuss-Hill average. All individual Cijs increase with pressure but C23 and C55 exhibit anomalously low pressure derivatives. From calculated linear compressibilities, the a-axis is the most compressible. The b-axis becomes the least compressible axis at high pressures. Over the examined pressure range, the azimuthal P-wave anisotropy decreased from 22% to 16%, while the azimuthal S-wave anisotropy increased from 15% to 21%. Both volume and axial compression curves calculated using our Brillouin results are in good agreement with the results from static compression studies. High-pressure sound velocities in diaspore exceed those of other hydrous minerals as well as many anhydrous phases relevant to Earth's upper mantle.

  9. Foreign gas broadening and shift of the strongly ``forbidden'' lead line at 1278.9nm

    Science.gov (United States)

    Horvatic, Vlasta; Veza, Damir; Movre, Mladen; Niemax, Kay; Vadla, Cedomil

    2008-06-01

    The collisional broadening and shift rate coefficients of the "forbidden" 6p 2 3P 0 → 6p 2 3P 1 transition in lead were determined by diode laser absorption measurements performed simultaneously in two resistively heated hot-pipes. One hot-pipe contained Pb vapor and noble gas (Ar or He) at low pressure, while the other was filled with Pb and noble gas at variable pressure. The measurements were performed at temperatures of 1220 K and 1290 K, i.e., lead number densities of 4.8 × 10 15 cm - 3 and 1.2 × 10 16 cm - 3 . The broadening rates were obtained by fitting the experimental collisionally broadened absorption line shapes to theoretical Voigt profiles. The shift rates were determined by measuring the difference between the peak absorption positions in the spectra measured simultaneously in the heat pipe filled with noble gas at reference pressure and the one with noble gas at variable pressure. The following data for the broadening and shift rate coefficients due to collisions with Ar and He were obtained: γBAr = (3.4 ± 0.1) × 10 - 10 cm 3 s - 1 , γBHe = (3.8 ± 0.1) × 10 - 10 cm 3 s - 1 , γSAr = (- 7.3 ± 0.8) × 10 - 11 cm 3 s - 1 , γSHe = (- 6.5 ± 0.7) × 10 - 11 cm 3 s - 1 .

  10. Physiological interpretation of inductance and low-resistance terms in four-element windkessel models: assessment by generalized sensitivity function analysis.

    Science.gov (United States)

    Burattini, Roberto; Bini, Silvia

    2011-07-01

    Physiological relevance of parameters of three arterial models, denominated W4P, W4S and IVW, was assessed by computation of parameter-related generalized sensitivity functions (GSFs), which allow the definition of heart-cycle time intervals where the information content of experimental data, useful for estimation of each model parameter, is concentrated. The W4P and W4S are derived from the three-element windkessel by connecting an inductance, L, in parallel or in series, respectively, with aortic characteristic impedance, R(c). In the IVW, L is placed in series at the input of a viscoelastic windkessel, incorporating a Voigt cell (a resistor, R(d), in series with a capacitor, C). Pressure and flow measured in the ascending aorta of five ferrets and five dogs were used to estimate all model parameters, by fitting to pressure. For each model structure, parameter-related GSFs were generated. Focusing on controversial L, R(c) and R(d) physical meaning, our GSF analysis yielded the conclusion that, in both the W4S and the IVW, but not in the W4P, the L-term is suitable to represent the inertial properties of blood motion. Moreover, the meaning of aortic characteristic impedance ascribed to R(c) is questionable; while R(d) is likely to account for viscous losses of arterial wall motion.

  11. Ultra-fast and calibration-free temperature sensing in the intrapulse mode

    KAUST Repository

    Chrystie, Robin S. M.

    2014-11-20

    A simultaneously time-resolved and calibration-free sensor has been demonstrated to measure temperature at the nanosecond timescale at repetition rates of 1.0 MHz. The sensor benefits from relying on a single laser, is intuitive and straightforward to implement, and can sweep across spectral ranges in excess of 1 cm-1. The sensor can fully resolve rovibrational features of the CO molecule, native to combustion environments, in the mid-infrared range near X = 4.85 μm at typical combustion temperatures (800-2500 K) and pressures (1-3 atm). All of this is possible through the exploitation of chirp in a quantum cascade laser, operating at a duty cycle of 50%, and by using high bandwidth (500 MHz) photodetection. Here, we showcase uncluttered, spectrally-pure Voigt profile fitting with accompanying peak SNRs of 150, resulting in a typical temperature precision of 0.9% (1u) at an effective time-resolution of 1.0 MHz. Our sensor is applicable to other species, and canbe integrated into commercial technologies.

  12. Mechanical, piezoelectric and some thermal properties of (B3) BP under pressure

    Institute of Scientific and Technical Information of China (English)

    S.DAOUD; N.BIOUD; N.LEBGAA

    2014-01-01

    Some compounds of group III-V semiconductor materials exhibit very good piezoelectric, mechanical, and thermal properties and their use in surface acoustic wave (SAW) devices operating specially at GHz frequencies. These materials have been appreciated for a long time due to their high acoustic velocities, which are important parameters for active microelectromechanical systems (MEMS) devices. For this object, first-principles calculations of the anisotropy and the hydrostatic pressure effect on the mechanical, piezoelectric and some thermal properties of the (B3) boron phosphide are presented, using the density functional perturbation theory (DFPT). The independent elastic and compliance constants, the Reuss modulus, Voigt modulus, and the shear modulus, the Kleinman parameter, the Cauchy and Born coefficients, the elastic modulus, and the Poisson ratio for directions within the important crystallographic planes of this compound under pressure are obtained. The direct and converse piezoelectric coefficients, the longitudinal, transverse, and average sound velocity, the Debye temperature, and the Debye frequency of (B3) boron phosphide under pressure are also presented and compared with available experimental and theoretical data of the literature.

  13. HITRANonline: An online interface and the flexible representation of spectroscopic data in the HITRAN database

    Science.gov (United States)

    Hill, Christian; Gordon, Iouli E.; Kochanov, Roman V.; Barrett, Lorenzo; Wilzewski, Jonas S.; Rothman, Laurence S.

    2016-07-01

    We describe a new, online interface to the HITRAN database that overcomes the many limitations of the existing, 160-character fixed-width, text based format (the ".par" files mostly distributed through an FTP site until now). The interface, called HITRANonline, accesses a relational database [JQSRT 2013:130, 57-61] in which the spectroscopic data are stored in a flexible, extensible and structured format. This allows an arbitrary number of different parameters for each transition to be stored so that HITRAN can represent, for example, non-Voigt line shape profiles as well as parameters representing broadening by species other than "air" and "self". The online interface provides many ways of visualizing data as part of querying the database and allows users to create and save their own output formats to suit their own needs. A bibliography file produced with each data file provides citations and notes to the original data sources to make it easier for users to credit data providers. Once registered with the HITRANonline service, users also have (private) access to thier own search history which summarizes and can repeat queries.

  14. Wavelet-transform-based active imaging of cavitation bubbles in tissues induced by high intensity focused ultrasound.

    Science.gov (United States)

    Liu, Runna; Xu, Shanshan; Hu, Hong; Huo, Rui; Wang, Supin; Wan, Mingxi

    2016-08-01

    Cavitation detection and imaging are essential for monitoring high-intensity focused ultrasound (HIFU) therapies. In this paper, an active cavitation imaging method based on wavelet transform is proposed to enhance the contrast between the cavitation bubbles and surrounding tissues. The Yang-Church model, which is a combination of the Keller-Miksis equation with the Kelvin-Voigt equation for the pulsations of gas bubbles in simple linear viscoelastic solids, is utilized to construct the bubble wavelet. Experiments with porcine muscles demonstrate that image quality is associated with the initial radius of the bubble wavelet and the scale. Moreover, the Yang-Church model achieves a somewhat better performance compared with the Rayleigh-Plesset-Noltingk-Neppiras-Poritsky model. Furthermore, the pulse inversion (PI) technique is combined with bubble wavelet transform to achieve further improvement. The cavitation-to-tissue ratio (CTR) of the best tissue bubble wavelet transform (TBWT) mode image is improved by 5.1 dB compared with that of the B-mode image, while the CTR of the best PI-based TBWT mode image is improved by 7.9 dB compared with that of the PI-based B-mode image. This work will be useful for better monitoring of cavitation in HIFU-induced therapies.

  15. A biomechanical model for fluidization of cells under dynamic strain.

    Science.gov (United States)

    Wu, Tenghu; Feng, James J

    2015-01-06

    Recent experiments have investigated the response of smooth muscle cells to transient stretch-compress (SC) and compress-stretch (CS) maneuvers. The results indicate that the transient SC maneuver causes a sudden fluidization of the cell while the CS maneuver does not. To understand this asymmetric behavior, we have built a biomechanical model to probe the response of stress fibers to the two maneuvers. The model couples the cross-bridge cycle of myosin motors with a viscoelastic Kelvin-Voigt element that represents the stress fiber. Simulation results point to the sensitivity of the myosin detachment rate to tension as the cause for the asymmetric response of the stress fiber to the CS and SC maneuvers. For the SC maneuver, the initial stretch increases the tension in the stress fiber and suppresses myosin detachment. The subsequent compression then causes a large proportion of the myosin population to disengage rapidly from actin filaments. This leads to the disassembly of the stress fibers and the observed fluidization. In contrast, the CS maneuver only produces a mild loss of myosin motors and no fluidization.

  16. Structural and magnetic properties of turmeric functionalized CoFe2O4 nanocomposite powder

    Science.gov (United States)

    Mehran, E.; Farjami Shayesteh, S.; Sheykhan, M.

    2016-10-01

    The structural and magnetic properties of the synthesized pure and functionalized CoFe2O4 magnetic nanoparticles (NPs) are studied by analyzing the results from the x-ray diffraction (XRD), transmission electron microscopy (TEM), FT-IR spectroscopy, thermogravimetry (TG), and vibrating sample magnetometer (VSM). To extract the structure and lattice parameters from the XRD analysis results, we first apply the pseudo-Voigt model function to the experimental data obtained from XRD analysis and then the Rietveld algorithm is used in order to optimize the model function to estimate the true intensity values. Our simulated intensities are in good agreement with the experimental peaks, therefore, all structural parameters such as crystallite size and lattice constant are achieved through this simulation. Magnetic analysis reveals that the synthesized functionalized NPs have a saturation magnetization almost equal to that of pure nanoparticles (PNPs). It is also found that the presence of the turmeric causes a small reduction in coercivity of the functionalized NPs in comparison with PNP. Our TGA and FTIR results show that the turmeric is bonded very well to the surface of the NPs. So it can be inferred that a nancomposite (NC) powder of turmeric and nanoparticles is produced. As an application, the anti-arsenic characteristic of turmeric makes the synthesized functionalized NPs or NC powder a good candidate for arsenic removal from polluted industrial waste water. Project supported by the University of Guilan and the Iran Nanotechnology Initiative Council.

  17. Quenched Cold Accretion of a Large Scale Metal-Poor Filament due to Virial Shocking in the Halo of a Massive z=0.7 Galaxy

    CERN Document Server

    Churchill, Christopher W; Steidel, Charles C; Spitler, Lee R; Holtzman, Jon; Nielsen, Nikole M; Trujillo-Gomez, Sebastian

    2012-01-01

    Using HST/COS/STIS and HIRES/Keck high-resolution spectra, we have studied a remarkable HI absorbing complex at z=0.672 toward the quasar Q1317+277. The HI absorption has a velocity spread of 1600 km/s, comprises 21 Voigt profile components, and resides at an impact parameter of D=58 kpc from a bright, high mass [log(M_vir/M_sun) ~ 13.7] elliptical galaxy that is deduced to have a 6 Gyr old, solar metallicity stellar population. Ionization models suggest the majority of the structure is cold gas surrounding a shock heated cloud that is kinematically adjacent to a multi-phase group of clouds with detected CIII, CIV and OVI absorption, suggestive of a conductive interface near the shock. The deduced metallicities are consistent with the moderate in situ enrichment relative to the levels observed in the z ~ 3 Ly-alpha forest. We interpret the HI complex as a metal-poor filamentary structure being shock heated as it accretes into the halo of the galaxy. The data support the scenario of an early formation period (...

  18. The Column Density Distribution of the Low-Redshift Lyman-Alpha Forest in Illustris

    CERN Document Server

    Gurvich, Alex; Bird, Simeon

    2016-01-01

    We investigate the low-redshift Lyman-alpha forest column density distribution in the Illustris simulation. We show that Illustris reproduces observations extremely well in the column density range 10^12.5-10^14.5 cm^-2, relevant for the "photon underproduction crisis." We attribute this to the inclusion of AGN feedback, which changes the gas distribution so as to mimic the effect of extra photons, as well as the use of the Faucher-Giguere (2009) ultra-violet background, which is more ionizing at z=0.1 than the Haardt & Madau (2012) background previously considered. We show that the difference between simulations run with smoothed particle hydrodynamics and simulations using a moving mesh is small in this column density range. We further consider the effect of supernova feedback, Voigt profile fitting and finite resolution, all of which we show to be small. Finally, we identify a discrepancy between our simulations and observations at column densities 10^14-10^16 cm^-2, where Illustris produces too few ab...

  19. Properties of QSO Metal Line Absorption Systems at High Redshifts: Nature and Evolution of the Absorbers and New Evidence on Escape of Ionizing Radiation from Galaxies

    CERN Document Server

    Boksenberg, Alec

    2014-01-01

    Using Voigt-profile-fitting procedures on Keck HIRES spectra of nine QSOs we identify 1099 CIV absorber components clumped in 201 systems outside the Lyman forest over 1.6 < z < 4.4. With associated SiIV, CII, SiII and NV where available we investigate bulk statistical and ionization properties of the components and systems and find no significant change in redshift for CIV and SiIV while CII, SiII and NV change substantially. The CIV components exhibit strong clustering but no clustering is detected for systems on scales from 150 km/s out to 50000 km/s. We conclude the clustering is due entirely to the peculiar velocities of gas present in the circumgalactic media of galaxies. Using specific combinations of ionic ratios we compare our observations with model ionization predictions for absorbers exposed to the metagalactic ionizing radiation background augmented by proximity radiation from their associated galaxies and find the generally accepted means of radiative escape by transparent channels from th...

  20. Nonlinear vibration of viscoelastic embedded-DWCNTs integrated with piezoelectric layers-conveying viscous fluid considering surface effects

    Science.gov (United States)

    Fereidoon, A.; Andalib, E.; Mirafzal, A.

    2016-07-01

    This article studies the nonlinear vibration of viscoelastic embedded nano-sandwich structures containing of a double walled carbon nanotube (DWCNT) integrated with two piezoelectric Zinc oxide (ZnO) layers. DWCNT and ZnO layers are subjected to magnetic and electric fields, respectively. This system is conveying viscous fluid and the related force is calculated by modified Navier-Stokes relation considering slip boundary condition and Knudsen number. Visco-Pasternak model with three parameters of the Winkler modulus, shear modulus, and damp coefficient is used for simulation of viscoelastic medium. The nano-structure is simulated as an orthotropic Timoshenko beam (TB) and the effects of small scale, structural damping and surface stress are considered based on Eringen's, Kelvin-voigt and Gurtin-Murdoch theories. Energy method and Hamilton's principle are employed to derive motion equations which are then solved using differential quadrature method (DQM). The detailed parametric study is conducted, focusing on the combined effects of small scale effect, fluid velocity, thickness of piezoelectric layer, boundary condition, surface effects, van der Waals (vdW) force on the frequency and critical velocity of nano-structure. Results indicate that the frequency and critical velocity increases with assume of surface effects.

  1. Photoacoustic Spectroscopy of - and - Dependence in the O_{2} A-Band

    Science.gov (United States)

    Cich, Matthew J.; Lunny, Elizabeth M.; Stroscio, Gautam; Bui, Thinh Quoc; Rupasinghe, Priyanka; Hogan, Daniel; Bray, Caitlin; Long, David A.; Hodges, Joseph T.; Crawford, Timothy J.; Miller, Charles; Drouin, Brian; Okumura, Mitchio

    2017-06-01

    NASA's Orbiting Carbon Observatory missions OCO-2 and OCO-3 require spectroscopic parameterization of the Oxygen A-Band absorption (757-775 nm) with unprecedented precision, to deliver space-based measurements of CO_{2} column densities with an accuracy of better than 0.1%. Furthermore, with the long satellite-based pathlengths, the strongest A-Band lines are saturated. Accurate retrievals of O_{2} column densities thus require precise modeling of the line shape, including the wings several linewidths from line center. The line shape model must go beyond the Voigt profile to include higher order effects such as Dicke narrowing, speed dependence, line mixing (LM), and collision-induced absorption (CIA). High precision laboratory data targeting these effects must be taken. Line mixing and collision induced absorption have proven to be especially problematic in satellite retrievals of O_{2} column densities. LM and CIA are more prominent at lower temperatures and higher pressures. A temperature-stabilized photoacoustic spectrometer was therefore designed to study the temperature- and pressure-dependence of spectral line shapes at temperatures from 230-296 K and pressures up to 5 atm. Progress toward high resolution (2 MHz) measurements of the full A-Band will be presented. The observed lineshapes are analyzed with the Hartmann-Tran Profile (HTP), which incorporates LM and CIA , using the Labfit multispectrum fitting program, and the determination of LM and CIA effects will be presented.

  2. Multispectrum analysis of the oxygen A-band

    Science.gov (United States)

    Drouin, Brian J.; Benner, D. Chris; Brown, Linda R.; Cich, Matthew J.; Crawford, Timothy J.; Devi, V. Malathy; Guillaume, Alexander; Hodges, Joseph T.; Mlawer, Eli J.; Robichaud, David J.; Oyafuso, Fabiano; Payne, Vivienne H.; Sung, Keeyoon; Wishnow, Edward H.; Yu, Shanshan

    2017-01-01

    Retrievals of atmospheric composition from near-infrared measurements require measurements of airmass to better than the desired precision of the composition. The oxygen bands are obvious choices to quantify airmass since the mixing ratio of oxygen is fixed over the full range of atmospheric conditions. The OCO-2 mission is currently retrieving carbon dioxide concentration using the oxygen A-band for airmass normalization. The 0.25% accuracy desired for the carbon dioxide concentration has pushed the required state-of-the-art for oxygen spectroscopy. To measure O2 A-band cross-sections with such accuracy through the full range of atmospheric pressure requires a sophisticated line-shape model (Rautian or Speed-Dependent Voigt) with line mixing (LM) and collision induced absorption (CIA). Models of each of these phenomena exist, however, this work presents an integrated self-consistent model developed to ensure the best accuracy. It is also important to consider multiple sources of spectroscopic data for such a study in order to improve the dynamic range of the model and to minimize effects of instrumentation and associated systematic errors. The techniques of Fourier Transform Spectroscopy (FTS) and Cavity Ring-Down Spectroscopy (CRDS) allow complimentary information for such an analysis. We utilize multispectrum fitting software to generate a comprehensive new database with improved accuracy based on these datasets. The extensive information will be made available as a multi-dimensional cross-section (ABSCO) table and the parameterization will be offered for inclusion in the HITRANonline database.

  3. A modeling study of notch noise responses of type III units in the gerbil dorsal cochlear nucleus.

    Science.gov (United States)

    Zheng, Xiaohan; Voigt, Herbert F

    2006-12-01

    A computational model of the neural circuitry of the gerbil dorsal cochlear nucleus (DCN), based on the MacGregor's neuromime model, was used to simulate type III unit (P-cell) responses to notch noise stimuli. The DCN patch model is based on a previous computational model of the cat DCN [Hancock, K. E., and H. F. Voigt. Ann. Biomed. Eng. 27:73-87, 1999]. According to the experimental study of Parsons et al. [Ann. Biomed. Eng. 29:887-896, 2001], the responses of gerbil DCN type III units to notch noise stimuli are similar to those of cat DCN type IV units, which are thought to be spectral notch detectors. This suggests that type III units in the gerbil DCN may serve as spectral notch detectors. In this modeling study, a simplified notch noise response plot--spike discharge rate vs. notch cutoff frequency plot--was used to compare model responses to the experimental results. Parameter estimation and sensitivity analysis of three connection parameters within the DCN patch have been studied and shows the model is robust, providing reasonable fits to the experimental data from 14 of 15 type III units examined.

  4. Structural, elastic and electronic properties of superconducting anti-perovskites MgCNi 3, ZnCNi 3 and CdCNi 3 from first principles

    Science.gov (United States)

    Shein, I. R.; Bannikov, V. V.; Ivanovskii, A. L.

    2008-01-01

    First principle total energy calculations using the full potential linearized augmented plane wave (FP-LAPW) method with the generalized gradient approximation (GGA) for the exchange-correlation potential were performed to investigate the systematic trends for structural, elastic and electronic properties of the family of superconducting anti-perovskites MCNi 3 depending from the type of M cations (M are Mg, Zn and Cd). In result the optimized lattice parameters, independent elastic constants ( C11, C12 and C44), bulk modulus B, compressibility β, shear modulus G and tetragonal shear modulus G‧ are evaluated. Further, for the first time the numerical estimates of a set of elastic parameters (bulk and shear modulus, Young’s modulus Y, Poisson’s ratio ( ν), Lamé’s coefficients ( μ, λ)) of the polycrystalline superconducting MCNi 3 ceramics (in framework of the Voigt-Reuss-Hill approximation) were performed. Besides, the band structures, densities of states (DOS), total and site-projected l-decomposed DOS at the Fermi level, the shapes of the Fermi surfaces, the Sommerfeld’s coefficients and the molar Pauli paramagnetic susceptibility for these anti-perovskites were obtained and analyzed in comparison with the available theoretical and experimental data.

  5. Structural, elastic and electronic properties of superconducting anti-perovskites MgCNi{sub 3}, ZnCNi{sub 3} and CdCNi{sub 3} from first principles

    Energy Technology Data Exchange (ETDEWEB)

    Shein, I.R.; Bannikov, V.V. [Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 620041, Ekaterinburg (Russian Federation); Ivanovskii, A.L. [Institute of Solid State Chemistry, Ural Branch of the Russian Academy of Sciences, 620041, Ekaterinburg (Russian Federation)], E-mail: ivanovskii@ihim.uran.ru

    2008-01-01

    First principle total energy calculations using the full potential linearized augmented plane wave (FP-LAPW) method with the generalized gradient approximation (GGA) for the exchange-correlation potential were performed to investigate the systematic trends for structural, elastic and electronic properties of the family of superconducting anti-perovskites MCNi{sub 3} depending from the type of M cations (M are Mg, Zn and Cd). In result the optimized lattice parameters, independent elastic constants (C{sub 11}, C{sub 12} and C{sub 44}), bulk modulus B, compressibility {beta}, shear modulus G and tetragonal shear modulus G' are evaluated. Further, for the first time the numerical estimates of a set of elastic parameters (bulk and shear modulus, Young's modulus Y, Poisson's ratio ({nu}), Lame's coefficients ({mu}, {lambda})) of the polycrystalline superconducting MCNi{sub 3} ceramics (in framework of the Voigt-Reuss-Hill approximation) were performed. Besides, the band structures, densities of states (DOS), total and site-projected l-decomposed DOS at the Fermi level, the shapes of the Fermi surfaces, the Sommerfeld's coefficients and the molar Pauli paramagnetic susceptibility for these anti-perovskites were obtained and analyzed in comparison with the available theoretical and experimental data.

  6. Fractional-order viscoelasticity applied to describe uniaxial stress relaxation of human arteries

    Energy Technology Data Exchange (ETDEWEB)

    Craiem, Damian; Armentano, Ricardo L [Facultad de IngenierIa, Ciencias Exactas y Naturales, Favaloro University, Buenos Aires (Argentina); Rojo, Francisco J; Atienza, Jose Miguel; Guinea, Gustavo V [Departamento de Ciencia de Materiales, Universidad Politecnica de Madrid, Madrid (Spain)], E-mail: dcraiem@favaloro.edu.ar

    2008-09-07

    Viscoelastic models can be used to better understand arterial wall mechanics in physiological and pathological conditions. The arterial wall reveals very slow time-dependent decays in uniaxial stress-relaxation experiments, coherent with weak power-law functions. Quasi-linear viscoelastic (QLV) theory was successfully applied to modeling such responses, but an accurate estimation of the reduced relaxation function parameters can be very difficult. In this work, an alternative relaxation function based on fractional calculus theory is proposed to describe stress relaxation experiments in strips cut from healthy human aortas. Stress relaxation (1 h) was registered at three incremental stress levels. The novel relaxation function with three parameters was integrated into the QLV theory to fit experimental data. It was based in a modified Voigt model, including a fractional element of order {alpha}, called spring-pot. The stress-relaxation prediction was accurate and fast. Sensitivity plots for each parameter presented a minimum near their optimal values. Least-squares errors remained below 2%. Values of order {alpha} = 0.1-0.3 confirmed a predominant elastic behavior. The other two parameters of the model can be associated to elastic and viscous constants that explain the time course of the observed relaxation function. The fractional-order model integrated into the QLV theory proved to capture the essential features of the arterial wall mechanical response.

  7. The properties of photonic band gap and surface plasmon modes in the three-dimensional magnetized photonic crystals as the mixed polarized modes considered

    Science.gov (United States)

    Zhang, Hai-Feng; Liu, Shao-Bin; Jiang, Yu-Chi

    2015-04-01

    In this paper, the properties of photonic band gap (PBG) and surface plasmon modes in the three-dimensional (3D) magnetized plasma photonic crystals (MPPCs) with face-centered-cubic (fcc) lattices are theoretically investigated based on the plane wave expansion (PWE) method, in which the homogeneous magnetized plasma spheres are immersed in the homogeneous dielectric background, as the Voigt effects of magnetized plasma are considered (the incidence electromagnetic wave vector is perpendicular to the external magnetic field at any time). The dispersive properties of all of the EM modes are studied because the PBG is not only for the extraordinary and ordinary modes but also for the mixed polarized modes. The equations for PBGs also are theoretically deduced. The numerical results show that the PBG and a flatbands region can be observed. The effects of the dielectric constant of dielectric background, filling factor, plasma frequency and plasma cyclotron frequency (the external magnetic field) on the dispersive properties of all of the EM modes in such 3D MPPCs are investigated in detail, respectively. Theoretical simulations show that the PBG can be manipulated by the parameters as mentioned above. Compared to the conventional dielectric-air PCs with similar structure, the larger PBG can be obtained in such 3D MPPCs. It is also shown that the upper edge of flatbands region cannot be tuned by the filling factor and dielectric constant of dielectric background, but it can be manipulated by the plasma frequency and plasma cyclotron frequency.

  8. Rheological modelling of physiological variables during temperature variations at rest

    Science.gov (United States)

    Vogelaere, P.; de Meyer, F.

    1990-06-01

    The evolution with time of cardio-respiratory variables, blood pressure and body temperature has been studied on six males, resting in semi-nude conditions during short (30 min) cold stress exposure (0°C) and during passive recovery (60 min) at 20°C. Passive cold exposure does not induce a change in HR but increases VO 2, VCO 2 Ve and core temperature T re, whereas peripheral temperature is significantly lowered. The kinetic evolution of the studied variables was investigated using a Kelvin-Voigt rheological model. The results suggest that the human body, and by extension the measured physiological variables of its functioning, does not react as a perfect viscoelastic system. Cold exposure induces a more rapid adaptation for heart rate, blood pressure and skin temperatures than that observed during the rewarming period (20°C), whereas respiratory adjustments show an opposite evolution. During the cooling period of the experiment the adaptative mechanisms, taking effect to preserve core homeothermy and to obtain a higher oxygen supply, increase the energy loss of the body.

  9. Spectra calculations in central and wing regions of CO{sub 2} IR bands between 10 and 20 {mu}m. II. Atmospheric solar occultation spectra

    Energy Technology Data Exchange (ETDEWEB)

    Niro, F.; Hase, F.; Camy-Peyret, C.; Payan, S.; Hartmann, J.-M. E-mail: jean-michel.hartmann@ppm.u-psud.fr

    2005-01-01

    The theoretical approach based on the Energy Corrected Sudden Approximation presented in the previous companion paper is used in order to account for line-mixing effects in infrared bands of CO{sub 2}. Its performance, which was demonstrated using laboratory spectra is confirmed here by considering atmospheric transmission in the 10-14 {mu}m region. Comparisons are made between forward calculations of atmospheric transmission spectra and values measured using two different solar occultation experiments based on high resolution Fourier transform instruments. The results demonstrate that neglecting line-mixing and using a Voigt model can lead to a very large overestimation of absorption that may extend over more than 300 cm{sup -1} in the wing of the CO{sub 2} {nu}{sub 2} band. They also demonstrate the capability of our model to represent accurately the absorption in the entire region for a variety of atmospheric paths. Among positive consequences of the quality of the model, the possibility of retrieving amounts of (heavy) trace gases with weak and broad absorption features is demonstrated.

  10. A BEM formulation applied in the mechanical material modelling of viscoelastic cracked structures

    Science.gov (United States)

    Oliveira, Hugo Luiz; Leonel, Edson Denner

    2016-12-01

    The present study aims at performing a mechanical analysis of 2D viscoelastic cracked structural materials using the Boundary Element Method (BEM). The mesh dimensionality reduction provided by the BEM and its accuracy in representing high gradient fields make this numerical method robust to solve fracture mechanics problems. Viscoelastic models address phenomena that provide changes on the mechanical material properties along time. Well-established viscoelastic models such as Maxwell, Kelvin-Voigt and Boltzmann are used in this study. The numerical viscoelastic scheme, which is based on algebraic BEM equations, utilizes the Euler method for time derivative evaluation. Therefore, the unknown variables at the structural boundary and its variations along time are determined through an ordinary linear system of equations. Moreover, time-dependent boundary conditions may be considered, which represent loading phases. The dual BEM formulation is adopted for modelling the mechanical structural behaviour of cracks bodies. Three examples are considered to illustrate the robustness of the adopted formulation. The results achieved by the BEM are in good agreement with reported data and numerical stability is observed.

  11. Measurement of Young’s Modulus and Internal Damping of Pork Muscle in Dynamic Mode

    Science.gov (United States)

    Chakroun, Moez; Ghozlen, Med Hédi Ben

    2016-09-01

    Automotive shocks involve various tiers’ speed for different human body tissues. Knowing the behavior of these tissues, including muscles, in different vibration frequency is therefore necessary. The muscle has viscoelatic properties. Dynamically, this material has variable mechanical properties depending on the vibration frequency. A novel technique is being employed to examine the variation of the mechanical impedance of pork muscle as a function of frequency. A force is imposed on the lower surface of the sample and acceleration is measured on its upper surface. These two parameters are measured using sensors. The sample is modeled by Kelvin-Voigt model. These measures allow deducing the change in the mechanical impedance modulus (/Zexp/ = /Force: Acceleration/) of pork muscle as a function of vibration frequency. The measured impedance has a resonance of approximately 60Hz. Best-fit parameters of theoretical impedance can be deduced by superposition with the experiment result. The variation of Young’s modulus and internal damping of pig’s muscle as a function of frequency are determined. The results obtained between 5Hz and 30Hz are the same as determined by Aimedieu and al in 2003, therefore validating our technique. The Young’s modulus of muscle increases with the frequency, on the other hand, we note a rating decrease of internal damping.

  12. The Puzzling Spectrum of HD 94509

    CERN Document Server

    Cowley, C R; Hubrig, S

    2015-01-01

    The spectral features of HD 94509 are highly unusual, adding an extreme to the zoo of Be and shell stars. The shell dominates the spectrum, showing lines typical for spectral types mid-A to early-F, while the presence of a late/mid B-type central star is indicated by photospheric hydrogen line wings and helium lines. Numerous metallic absorption lines have broad wings but taper to narrow cores. They cannot be fit by Voigt profiles. We aim to describe and illustrate unusual spectral features of this star, and make rough calculations to estimate physical conditions and abundances in the shell. Furthermore, the central star is characterized. We assume mean conditions for the shell. An electron density estimate is made from the Inglis-Teller formula. Excitation temperatures and column densities for Fe I and Fe II are derived from curves of growth. The neutral H column density is estimated from high Paschen members. The column densities are compared with calculations made with the photoionization code Cloudy. Atmo...

  13. Constitutive equations for an electroactive polymer

    Science.gov (United States)

    Tixier, Mireille; Pouget, Joël

    2016-07-01

    Ionic electroactive polymers can be used as sensors or actuators. For this purpose, a thin film of polyelectrolyte is saturated with a solvent and sandwiched between two platinum electrodes. The solvent causes a complete dissociation of the polymer and the release of small cations. The application of an electric field across the thickness results in the bending of the strip and vice versa. The material is modeled by a two-phase continuous medium. The solid phase, constituted by the polymer backbone inlaid with anions, is depicted as a deformable porous media. The liquid phase is composed of the free cations and the solvent (usually water). We used a coarse grain model. The conservation laws of this system have been established in a previous work. The entropy balance law and the thermodynamic relations are first written for each phase and then for the complete material using a statistical average technique and the material derivative concept. One deduces the entropy production. Identifying generalized forces and fluxes provides the constitutive equations of the whole system: the stress-strain relations which satisfy a Kelvin-Voigt model, generalized Fourier's and Darcy's laws and the Nernst-Planck equation.

  14. Radiation trapping in atomic absorption spectroscopy at lead determination in different matricies

    Energy Technology Data Exchange (ETDEWEB)

    El-Gohary, Z. [Department of Physics, Faculty of Science, Menoufia University, Shebin El-Koom (Egypt)]. E-mail: zhelgohary@yahoo.com

    2005-08-15

    The determination of lead by flame atomic absorption analysis in the presence of Sn and Fe atoms and different matrices such as OH and SO{sub 3} was investigated with the objective of understanding the spectral interference processes at the analytical lines 283.31 nm for a wide range of concentration. The radiation trapping factor was interpreted and evaluated assuming Voigt distribution of the atomic and rotational lines in the flame. The radiation trapping factor was increased by increasing the number density (plasma of the absorbing medium is optically thick). In plasma, there is a certain point of equilibrium between the trapping and the escaping of radiation, which is relevant to 50% of absorption. The spectral background interference can cause a variation of the number density at equilibrium point as a result of the degree of overlap with the analytical line. The spectral background interference can be easily avoided by using another resonance absorption line for the analysis. The chemical modification of the matrix is applied to minimize the interference effect. Nitric acid, ammonium nitrate and magnesium nitrate are most commonly recommended as matrix modifiers.

  15. Radiation trapping in atomic absorption spectroscopy at lead determination in different matricies

    Science.gov (United States)

    El-Gohary, Z.

    2005-08-01

    The determination of lead by flame atomic absorption analysis in the presence of Sn and Fe atoms and different matrices such as OH and SO3 was investigated with the objective of understanding the spectral interference processes at the analytical lines 283.31 nm for a wide range of concentration. The radiation trapping factor was interpreted and evaluated assuming Voigt distribution of the atomic and rotational lines in the flame. The radiation trapping factor was increased by increasing the number density (plasma of the absorbing medium is optically thick). In plasma, there is a certain point of equilibrium between the trapping and the escaping of radiation, which is relevant to 50% of absorption. The spectral background interference can cause a variation of the number density at equilibrium point as a result of the degree of overlap with the analytical line. The spectral background interference can be easily avoided by using another resonance absorption line for the analysis. The chemical modification of the matrix is applied to minimize the interference effect. Nitric acid, ammonium nitrate and magnesium nitrate are most commonly recommended as matrix modifiers.

  16. Electric field development in γ-mode radiofrequency atmospheric pressure glow discharge in helium

    Science.gov (United States)

    Navrátil, Zdeněk; Josepson, Raavo; Cvetanović, Nikola; Obradović, Bratislav; Dvořák, Pavel

    2016-06-01

    Time development of electric field strength during radio-frequency sheath formation was measured using Stark polarization spectroscopy in a helium γ-mode radio-frequency (RF, 13.56 MHz) atmospheric pressure glow discharge at high current density (3 A cm-2). A method of time-correlated single photon counting was applied to record the temporal development of spectral profile of He I 492.2 nm line with a sub-nanosecond temporal resolution. By fitting the measured profile of the line with a combination of pseudo-Voigt profiles for forbidden (2 1P-4 1F) and allowed (2 1P-4 1D) helium lines, instantaneous electric fields up to 32 kV cm-1 were measured in the RF sheath. The measured electric field is in agreement with the spatially averaged value of 40 kV cm-1 estimated from homogeneous charge density RF sheath model. The observed rectangular waveform of the electric field time development is attributed to increased sheath conductivity by the strong electron avalanches occurring in the γ-mode sheath at high current densities.

  17. An Approach to Some Non-Classical Eigenvalue Problems of Structural Dynamics

    Directory of Open Access Journals (Sweden)

    Sandi Horea

    2015-12-01

    Full Text Available Two main shortcomings of common formulations, encountered in the literature concerning the linear problems of structural dynamics are revealed: the implicit, not discussed, postulation, of the use of Kelvin – Voigt constitutive laws (which is often infirmed by experience and the calculation difficulties involved by the attempts to use other constitutive laws. In order to overcome these two categories of shortcomings, the use of the bilateral Laplace – Carson transformation is adopted. Instead of the dependence on time, t, of a certain function f (t, the dependence of its image f# (p on the complex parameter p = χ + iω (ω: circular frequency will occur. This leads to the formulation of associated non-classical eigenvalue problems. The basic relations satisfied by the eigenvalues λr#(p and the eigenvectors vr#(p of dynamic systems are examined (among other, the property of orthogonality of eigenvectors is replaced by the property of pseudo-orthogonality. The case of points p = p’, where multiple eigenvalues occur and where, as a rule, chains of principal vectors are to be considered, is discussed. An illustrative case, concerning a non-classical eigenvalue problem, is presented. Plots of variation along the ω axis, for the real and imaginary components of eigenvalues and eigenvectors, are presented. A brief final discussion closes the paper.

  18. First-principles study of Al2Sm intermetallic compound on structural, mechanical properties and electronic structure

    Science.gov (United States)

    Lin, Jingwu; Wang, Lei; Hu, Zhi; Li, Xiao; Yan, Hong

    2017-02-01

    The structural, thermodynamic, mechanical and electronic properties of cubic Al2Sm intermetallic compound are investigated by the first-principles method on the basis of density functional theory. In light of the strong on-site Coulomb repulsion between the highly localized 4f electrons of Sm atoms, the local spin density approximation approach paired with additional Hubbard terms is employed to achieve appropriate results. Moreover, to examine the reliability of this study, the experimental value of lattice parameter is procured from the analysis of the TEM image and diffraction pattern of Al2Sm phase in the AZ31 alloy to verify the authenticity of the results originated from the computational method. The value of cohesive energy reveals Al2Sm to be a stable in absolute zero Kelvin. According to the stability criteria, the subject of this work is mechanically stable. Afterward, elastic moduli are deduced by performing Voigt-Reuss-Hill approximation. Furthermore, elastic anisotropy and anisotropy of sound velocity are discussed. Finally, the calculation of electronic density of states is implemented to explore the underlying mechanism of structural stability.

  19. Ethnomedicinal Plants of Barmer District, Rajasthan Used in Herbal and Folk Remedies

    Directory of Open Access Journals (Sweden)

    B.B.S. Kapoor1* and Sunil Kumar2

    2013-09-01

    Full Text Available The Barmer district a part of Thar Desert is very rich in herbal plant wealth. The herbal plants of this region havegreat potential to be used in drug and pharmaceutical industries. These herbal plants have been used by local people,tribal communities, vendors, native doctors such as Ojhas, Bhagats Bhopas and experts of Ayurvedic fields sincelong time in herbal and folk remedies. Kalbelia, Nats, Bhils, Raika, Bhopas, Banjara, Gadolia-Lohar Langa andManganiars communities of this district have a rich knowledge of plants based traditional medicines.Ethnomedicinal plants like Aristolochia bracteolata Lamk., Calligonum polygonoides Linn., Cardiospermumhalicacabum Linn., Clerodendrum phlomoidis Linn., Evolvulus alsinoides Linn., Grewia tenax (Forsk. Fiori.,Maytenus emarginata (Willd. Ding Hau., Mollugo Cerviana (Linn. Seringe. Neurada procumbens Linn., Ocimumamericanum Linn., Peganum harmala Linn., Pergularia daemia (Forsk Chiov., Portulaca oleracea Linn.,Sarcostemma acidum (Roxb. Voigt. and Trianthema portulacastrum Linn. have been selected for this researchwork.The present investigation is aimed to create awareness about the ethnomedicinal value of the plants and theiruses to draw the attention of pharmacologists, phytochemists and pharmaceuticals.

  20. Mechanical model for yield strength of nanocrystalline materials under high strain rate loading

    Institute of Scientific and Technical Information of China (English)

    朱荣涛; 周剑秋; 马璐; 张振忠

    2008-01-01

    To understand the high strain rate deformation mechanism and determine the grain size,strain rate and porosity dependent yield strength of nanocrystalline materials,a new mechanical model based on the deformation mechanism of nanocrystalline materials under high strain rate loading was developed.As a first step of the research,the yield behavior of the nanocrystalline materials under high strain rate loading was mainly concerned in the model and uniform deformation was assumed for simplification.Nanocrystalline materials were treated as composites consisting of grain interior phase and grain boundary phase,and grain interior and grain boundary deformation mechanisms under high strain rate loading were analyzed,then Voigt model was applied to coupling grain boundary constitutive relation with mechanical model for grain interior phase to describe the overall yield mechanical behavior of nanocrystalline materials.The predictions by the developed model on the yield strength of nanocrysatlline materials at high strain rates show good agreements with various experimental data.Further discussion was presented for calculation results and relative experimental observations.