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Sample records for radial expansion reactivity

  1. Radial core expansion reactivity feedback in advanced LMRs: uncertainties and their effects on inherent safety

    International Nuclear Information System (INIS)

    Wigeland, R.A.; Moran, T.J.

    1988-01-01

    An analytical model for calculating radial core expansion, based on the thermal and elastic bowing of a single subassembly at the core periphery, is used to quantify the effect of uncertainties on this reactivity feedback mechanism. This model has been verified and validated with experimental and numerical results. The impact of these uncertainties on the safety margins in unprotected transients is investigated with SASSYS/SAS4A, which includes this model for calculating the reactivity feedback from radial core expansion. The magnitudes of these uncertainties are not sufficient to preclude the use of radial core expansion reactivity feedback in transient analysis

  2. A simple reactivity feedback model accounting for radial core expansion effects in the liquid metal fast reactor

    International Nuclear Information System (INIS)

    Kwon, Young Min; Lee, Yong Bum; Chang, Won Pyo; Haha, Do Hee

    2002-01-01

    The radial core expansion due to the structure temperature rise is one of major negative reactivity insertion mechanisms in metallic fueled reactor. Thermal expansion is a result of both the laws of nature and the particular core design and it causes negative reactivity feedback by the combination of increased core volume captures and increased core surface leakage. The simple radial core expansion reactivity feedback model developed for the SSC-K code was evaluated by the code-to-code comparison analysis. From the comparison results, it can be stated that the radial core expansion reactivity feedback model employed into the SSC-K code may be reasonably accurate in the UTOP analysis

  3. A simple reactivity feedback model accounting for radial core expansion effects in the liquid metal fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Young Min; Lee, Yong Bum; Chang, Won Pyo; Haha, Do Hee [KAERI, Taejon (Korea, Republic of)

    2002-10-01

    The radial core expansion due to the structure temperature rise is one of major negative reactivity insertion mechanisms in metallic fueled reactor. Thermal expansion is a result of both the laws of nature and the particular core design and it causes negative reactivity feedback by the combination of increased core volume captures and increased core surface leakage. The simple radial core expansion reactivity feedback model developed for the SSC-K code was evaluated by the code-to-code comparison analysis. From the comparison results, it can be stated that the radial core expansion reactivity feedback model employed into the SSC-K code may be reasonably accurate in the UTOP analysis.

  4. Comparison of the SASSYS/SAS4A radial core expansion reactivity feedback model and the empirical correlation for FFTF

    International Nuclear Information System (INIS)

    Wigeland, R.A.

    1987-01-01

    The present emphasis on inherent safety for LMR designs has resulted in a need to represent the various reactivity feedback mechanisms as accurately as possible. The dominant negative reactivity feedback has been found to result from radial expansion of the core for most postulated ATWS events. For this reason, a more detailed model for calculating the reactivity feedback from radial core expansion has been recently developed for use with the SASSYS/SAS4A Code System. The purpose of this summary is to present an extension to the model so that it is more suitable for handling a core restraint design as used in FFTF, and to compare the SASSYS/SAS4A results using this model to the empirical correlation presently being used to account for radial core expansion reactivity feedback to FFTF

  5. Investigation of Reactivity Feedback Mechanism of Axial and Radial Expansion Effect of Metal-Fueled Sodium-Cooled Fast Reactor

    International Nuclear Information System (INIS)

    Seong, Seung-Hwan; Choi, Chi-Woong; Jeong, Tae-Kyung; Ha, Gi-Seok

    2015-01-01

    The major inherent reactivity feedback models for a ceramic fuel used in a conventional light water reactor are Doppler feedback and moderator feedback. The metal fuel has these two reactivity feedback mechanisms previously mentioned. In addition, the metal fuel has two more reactivity feedback models related to the thermal expansion phenomena of the metal fuel. Since the metal fuel has a good capability to expand according to the temperature changes of the core, two more feedback mechanisms exist. These additional two feedback mechanism are important to the inherent safety of metal fuel and can make metal-fueled SFR safer than oxide-fueled SFR. These phenomena have already been applied to safety analysis on design extended condition. In this study, the effect of these characteristics on power control capability was examined through a simple load change operation. The axial expansion mechanism is induced from the change of the fuel temperature according to the change of the power level of PGSFR. When the power increases, the fuel temperatures in the metal fuel will increase and then the reactivity will decrease due to the axial elongation of the metal fuel. To evaluate the expansion effect, 2 cases were simulated with the same scenario by using MMS-LMR code developed at KAERI. The first simulation was to analyze the change of the reactor power according to the change of BOP power without the reactivity feedback model of the axial and radial expansion of the core during the power transient event. That is to say, the core had only two reactivity feedback mechanism of Doppler and coolant temperature

  6. Radial expansion and multifragmentation

    International Nuclear Information System (INIS)

    Angelique, J.C.; Bizard, G.; Bougault, R.; Brou, R.; Buta, A.; Colin, J.; Cussol, D.; Durand, D.; Kerambrun, A.; Le Brun, C.; Lecolley, J.F.; Lopez, O.; Louvel, M.; Meslin, C.; Nakagawa, T.; Patry, J.P.; Peter, J.; Popescu, R.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Yuasa-Nakagawa, K.; Wieloch, A.

    1998-01-01

    The light systems 36 Ar + 27 Al and 64 Zn + nat Ti were measured at several bombarding energies between ∼ 35 and 95 MeV/nucleon. It was found that the predominant part of the cross section is due to binary collisions. In this paper the focus is placed on the properties of the quasi-projectile nuclei. In the central collisions the excitation energies of the quasi-projectile reach values exceeding largely 10 MeV/nucleon. The slope of the high energy part of the distribution can give only an upper limit of the apparent temperature (the average temperature along the decay chain). The highly excited quasi-projectile may get rapidly fragmented rather than sequentially. The heavy fragments are excited and can emit light particles (n, p, d, t, 3 He, α,...) what perturbs additionally the spectrum of these particles. Concerning the expansion energy, one can determine the average kinetic energies of the product (in the quasi-projectile-framework) and compare with simulation values. To fit the experimental data an additional radial expansion energy is to be considered. The average expansion energy depends slightly on the impact parameter but it increases with E * / A, ranging from 0.4 to 1,2 MeV/nucleon for an excitation energy increasing from 7 to 10.5 MeV/nucleon. This collective radial energy seems to be independent of the fragment mass, what is possibly valid for the case of larger quasi-projectile masses. The origin of the expansion is to be determined. It may be due to a compression in the interaction zone at the initial stage of the collision, which propagates in the quasi-projectile and quasi-target, or else, may be due, simply, to the increase of thermal energy leading to a rapid fragment emission. The sequential de-excitation calculation overestimates light particle emission and consequently heavy residues, particularly, at higher excitation energies. This disagreement indicates that a sequential process can not account for the di-excitation of very hot nuclei

  7. Radial expansion for spinning conformal blocks

    CERN Document Server

    Costa, Miguel S.; Penedones, João; Trevisani, Emilio

    2016-07-12

    This paper develops a method to compute any bosonic conformal block as a series expansion in the optimal radial coordinate introduced by Hogervorst and Rychkov. The method reduces to the known result when the external operators are all the same scalar operator, but it allows to compute conformal blocks for external operators with spin. Moreover, we explain how to write closed form recursion relations for the coefficients of the expansions. We study three examples of four point functions in detail: one vector and three scalars; two vectors and two scalars; two spin 2 tensors and two scalars. Finally, for the case of two external vectors, we also provide a more efficient way to generate the series expansion using the analytic structure of the blocks as a function of the scaling dimension of the exchanged operator.

  8. Initial Comparison of Direct and Legacy Modeling Approaches for Radial Core Expansion Analysis

    International Nuclear Information System (INIS)

    Shemon, Emily R.

    2016-01-01

    Radial core expansion in sodium-cooled fast reactors provides an important reactivity feedback effect. As the reactor power increases due to normal start up conditions or accident scenarios, the core and surrounding materials heat up, causing both grid plate expansion and bowing of the assembly ducts. When the core restraint system is designed correctly, the resulting structural deformations introduce negative reactivity which decreases the reactor power. Historically, an indirect procedure has been used to estimate the reactivity feedback due to structural deformation which relies upon perturbation theory and coupling legacy physics codes with limited geometry capabilities. With advancements in modeling and simulation, radial core expansion phenomena can now be modeled directly, providing an assessment of the accuracy of the reactivity feedback coefficients generated by indirect legacy methods. Recently a new capability was added to the PROTEUS-SN unstructured geometry neutron transport solver to analyze deformed meshes quickly and directly. By supplying the deformed mesh in addition to the base configuration input files, PROTEUS-SN automatically processes material adjustments including calculation of region densities to conserve mass, calculation of isotopic densities according to material models (for example, sodium density as a function of temperature), and subsequent re-homogenization of materials. To verify the new capability of directly simulating deformed meshes, PROTEUS-SN was used to compute reactivity feedback for a series of contrived yet representative deformed configurations for the Advanced Burner Test Reactor design. The indirect legacy procedure was also performed to generate reactivity feedback coefficients for the same deformed configurations. Interestingly, the legacy procedure consistently overestimated reactivity feedbacks by 35% compared to direct simulations by PROTEUS-SN. This overestimation indicates that the legacy procedures are in fact

  9. Initial Comparison of Direct and Legacy Modeling Approaches for Radial Core Expansion Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shemon, Emily R. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-10-10

    Radial core expansion in sodium-cooled fast reactors provides an important reactivity feedback effect. As the reactor power increases due to normal start up conditions or accident scenarios, the core and surrounding materials heat up, causing both grid plate expansion and bowing of the assembly ducts. When the core restraint system is designed correctly, the resulting structural deformations introduce negative reactivity which decreases the reactor power. Historically, an indirect procedure has been used to estimate the reactivity feedback due to structural deformation which relies upon perturbation theory and coupling legacy physics codes with limited geometry capabilities. With advancements in modeling and simulation, radial core expansion phenomena can now be modeled directly, providing an assessment of the accuracy of the reactivity feedback coefficients generated by indirect legacy methods. Recently a new capability was added to the PROTEUS-SN unstructured geometry neutron transport solver to analyze deformed meshes quickly and directly. By supplying the deformed mesh in addition to the base configuration input files, PROTEUS-SN automatically processes material adjustments including calculation of region densities to conserve mass, calculation of isotopic densities according to material models (for example, sodium density as a function of temperature), and subsequent re-homogenization of materials. To verify the new capability of directly simulating deformed meshes, PROTEUS-SN was used to compute reactivity feedback for a series of contrived yet representative deformed configurations for the Advanced Burner Test Reactor design. The indirect legacy procedure was also performed to generate reactivity feedback coefficients for the same deformed configurations. Interestingly, the legacy procedure consistently overestimated reactivity feedbacks by 35% compared to direct simulations by PROTEUS-SN. This overestimation indicates that the legacy procedures are in fact

  10. Critical experiment tests of bowing and expansion reactivity calculations for LMRS

    International Nuclear Information System (INIS)

    Schaefer, R.W.

    1988-01-01

    Experiments done in several LMR-type critical assemblies simulated core axial expansion, core radial expansion and bowing, coolant expansion, and control driveline expansion. For the most part new experimental techniques were developed to do these experiments. Calculations of the experiments basically used design-level methods, except when it was necessary to investigate complexities peculiar to the experiments. It was found that these feedback reactivities generally are overpredicted, but the predictions are within 30% of the experimental values. 14 refs., 2 figs., 4 tabs

  11. Interplay between Mach cone and radial expansion in jet events

    Energy Technology Data Exchange (ETDEWEB)

    Tachibana, Y., E-mail: tachibana@nt.phys.s.u-tokyo.ac.jp [Theoretical Research Division, Nishina Center, RIKEN, Wako 351-0198 (Japan); Department of Engineering, Nishinippon Institute of Technology, Fukuoka 800-0344 (Japan); Department of Physics, Sophia University, Tokyo 102-8554 (Japan); Hirano, T., E-mail: hirano@sophia.ac.jp [Department of Physics, Sophia University, Tokyo 102-8554 (Japan)

    2016-12-15

    We study the hydrodynamic response to jet propagation in the expanding QGP and investigate how the particle spectra after the hydrodynamic evolution of the QGP reflect it. We perform simulations of the space-time evolution of the QGP in gamma-jet events by solving (3+1)-dimensional ideal hydrodynamic equations with source terms. Mach cone is induced by the jet energy deposition and pushes back the radial flow of the expanding background. Especially in the case when the jet passage is off-central one, the number of particles emitted in the direction of the push back decreases. This is the signal including the information about the formation of the Mach cone and the jet passage in the QGP fluid.

  12. Interplay between Mach cone and radial expansion in jet events

    International Nuclear Information System (INIS)

    Tachibana, Y.; Hirano, T.

    2016-01-01

    We study the hydrodynamic response to jet propagation in the expanding QGP and investigate how the particle spectra after the hydrodynamic evolution of the QGP reflect it. We perform simulations of the space-time evolution of the QGP in gamma-jet events by solving (3+1)-dimensional ideal hydrodynamic equations with source terms. Mach cone is induced by the jet energy deposition and pushes back the radial flow of the expanding background. Especially in the case when the jet passage is off-central one, the number of particles emitted in the direction of the push back decreases. This is the signal including the information about the formation of the Mach cone and the jet passage in the QGP fluid.

  13. Temperature-monitored optical treatment for radial tissue expansion.

    Science.gov (United States)

    Bak, Jinoh; Kang, Hyun Wook

    2017-07-01

    Esophageal stricture occurs in 7-23% of patients with gastroesophageal reflux disease. However, the current treatments including stent therapy, balloon dilation, and bougienage involve limitations such as stent migration, formation of the new strictures, and snowplow effect. The purpose of the current study was to investigate the feasibility of structural expansion in tubular tissue ex vivo during temperature-monitored photothermal treatment with a diffusing applicator for esophageal stricture. Porcine liver was used as an ex vivo tissue sample for the current study. A glass tube was used to maintain a constant distance between the diffuser and tissue surface and to evaluate any variations in the luminal area after 10-W 1470-nm laser irradiation for potential stricture treatment. The 3D goniometer measurements confirmed roughly isotropic distribution with less than 10% deviation from the average angular intensity over 2π (i.e., 0.86 ± 0.09 in arbitrary unit) from the diffusing applicator. The 30-s irradiation increased the tissue temperature up to 72.5 °C, but due to temperature feedback, the interstitial tissue temperature became saturated at 70 °C (i.e., steady-state error = ±0.4 °C). The irradiation times longer than 5 s presented area expansion index of 1.00 ± 0.04, signifying that irreversible tissue denaturation permanently deformed the lumen in a circular shape and secured the equivalent luminal area to that of the glass tube. Application of a temperature feedback controller for photothermal treatment with the diffusing applicator can regulate the degree of thermal denaturation to feasibly treat esophageal stricture in a tubular tissue.

  14. Differences in radial expansion force among inferior vena cava filter models support documented perforation rates.

    Science.gov (United States)

    Robins, J Eli; Ragai, Ihab; Yamaguchi, Dean J

    2018-05-01

    Inferior vena cava (IVC) filters are used in patients at risk for pulmonary embolism who cannot be anticoagulated. Unfortunately, these filters are not without risk, and complications include perforation, migration, and filter fracture. The most prevalent complication is filter perforation of the IVC, with incidence varying among filter models. To our knowledge, the mechanical properties of IVC filters have not been evaluated and are not readily available through the manufacturer. This study sought to determine whether differences in mechanical properties are similar to differences in documented perforation rates. The radial expansion forces of Greenfield (Boston Scientific, Marlborough, Mass), Cook Celect (Cook Medical, Bloomington, Ind), and Cook Platinum filters were analyzed with three replicates per group. The intrinsic force exerted by the filter on the measuring device was collected in real time during controlled expansion. Replicates were averaged and significance was determined by calculating analysis of covariance using SAS software (SAS Institute, Cary, NC). Each filter model generated a significantly different radial expansion force (P filter, followed by the Cook Celect and Greenfield filters. Radial force dispersion during expansion was greatest in the Cook Celect, followed by the Cook Platinum and Greenfield filters. Differences in radial expansion forces among IVC filter models are consistent with documented perforation rates. Cook Celect IVC filters have a higher incidence of perforation compared with Greenfield filters when they are left in place for >90 days. Evaluation of Cook Celect filters yielded a significantly higher radial expansion force at minimum caval diameter, with greater force dispersion during expansion. Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  15. A Mathematical Model for Temperature Induced Loosening due to Radial Expansion of Rectangle Thread Bolted Joints

    Directory of Open Access Journals (Sweden)

    Shiyuan Hou

    2015-01-01

    Full Text Available This paper proposed a mathematical model to investigate the radial expansion induced loosening of rectangle thread bolted joints that were subjected to cyclic temperature variation, which could cause slippage between contact pairs of engaged threads and bolt bearing. Firstly, integral equations were derived for the shear stress components caused by expansion difference, as well as the bearing and thread friction torque components, which depended on the temperature variation. Secondly, the relationship of displacement components was developed based on quasi-static hypotheses. Then, treating the rotation of bolt as plastic elongation, the bolt tension's evolution was obtained by using a one-dimensional bolted joint model. Numerical results showed that the temperature variation decreased the bearing and thread friction torque components, which could lead bolted joint to loosen. Finally, the effects of some associated factors on the progress were discussed.

  16. Reactivity worth of gas expansion modules (GEMs) in the fast flux test facility

    International Nuclear Information System (INIS)

    Campbell, L.R.; Nelson, J.V.; Burke, T.M.; Rawlins, J.A.; Daughtry, J.W.; Bennett, R.A.

    1986-01-01

    A new passive shutdown device called a gas expansion module (GEM) has been developed at Hanford Engineering Development Laboratory to insert negative reactivity during a primary system loss of flow in a liquid-metal reactor (LMR). A GEM is a hollow removable core component which is sealed at the top and open at the bottom. An argon gas bubble trapped inside the assembly expands when core inlet pressure decreases (caused by a flow reduction) and expels sodium from the assembly. The GEMs are designed so that the level of the liquid-sodium primary system coolant within a GEM is above the top of the core when the primary pumps are operating at full flow and is below the bottom of the core when the primary pumps are off. When a GEM is placed at the boundary of the core and radial reflector, the drop in sodium level increases core neutron leakage and inserts negative reactivity. The results of these measurements confirm the effectiveness of GEMs in adding negative reactivity in loss-of-flow situations. It follows, therefore, that the inherent safety of LMRs, comparable in size to the FFTF, can be enhanced by the use of GEMs

  17. Effects of Radial Reflector Composition on Core Reactivity and Peak Power

    International Nuclear Information System (INIS)

    Park, Sang Yoon; Lee, Kyung Hoon; Song, Jae Seung

    2007-10-01

    The effects of radial SA-240 alloy shroud on core reactivity and peak power are evaluated. The existence of radial SA-240 alloy shroud makes reflector water volume decrease, so the thermal absorption cross section of radial reflector is lower than without SA-240 alloy shroud case. Finally, the cycle length is increased from 788 EFPD to 845 EFPD and the peak power is decreased from 1.66 to 1.49. In the case of without SA-240 alloy shroud, a new core loading pattern search has been performed. For the guarantee of the same equivalent cycle length of with SA-240 alloy shroud case, the enrichment of U-235 should be increased from 4.22 w/o to 4.68 w/o. The nuclear key safety parameters of new core loading pattern have been calculated and recorded for the future

  18. Effects of Radial Reflector Composition on Core Reactivity and Peak Power

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Yoon; Lee, Kyung Hoon; Song, Jae Seung

    2007-10-15

    The effects of radial SA-240 alloy shroud on core reactivity and peak power are evaluated. The existence of radial SA-240 alloy shroud makes reflector water volume decrease, so the thermal absorption cross section of radial reflector is lower than without SA-240 alloy shroud case. Finally, the cycle length is increased from 788 EFPD to 845 EFPD and the peak power is decreased from 1.66 to 1.49. In the case of without SA-240 alloy shroud, a new core loading pattern search has been performed. For the guarantee of the same equivalent cycle length of with SA-240 alloy shroud case, the enrichment of U-235 should be increased from 4.22 w/o to 4.68 w/o. The nuclear key safety parameters of new core loading pattern have been calculated and recorded for the future.

  19. Formula for radial profiles of temperature in steam-liquid sodium reactive jets

    International Nuclear Information System (INIS)

    Hobbes, P.; Mora-Perez, J.L.; Carreau, J.L.; Gbahoue, L.; Roger, F.

    1987-01-01

    One of the important problems of the study of distribution of temperatures in the reactive steam-liquid sodium jet rests in the mathematical formulation of their radial effects. During the experiment, two forms have been brought to light: from a certain distance of the injector, the radial distribution of temperature can be represented, in a classical way, by an error function curve; close to the injector, the radial profile allows for a minimum located on the axis of the jet. An energy balance permits, by dividing the jet in three parts: a central nucleus composed of practically pure gas, a gas ring plus drops and a liquid peripheral area plus bubbles, to obtain a mathematical formulation of the profiles, close to the injection which accounts quite well for the experimental points and their form

  20. Comparison between maximum radial expansion of ultrasound contrast agents and experimental postexcitation signal results.

    Science.gov (United States)

    King, Daniel A; O'Brien, William D

    2011-01-01

    Experimental postexcitation signal data of collapsing Definity microbubbles are compared with the Marmottant theoretical model for large amplitude oscillations of ultrasound contrast agents (UCAs). After taking into account the insonifying pulse characteristics and size distribution of the population of UCAs, a good comparison between simulated results and previously measured experimental data is obtained by determining a threshold maximum radial expansion (Rmax) to indicate the onset of postexcitation. This threshold Rmax is found to range from 3.4 to 8.0 times the initial bubble radius, R0, depending on insonification frequency. These values are well above the typical free bubble inertial cavitation threshold commonly chosen at 2R0. The close agreement between the experiment and models suggests that lipid-shelled UCAs behave as unshelled bubbles during most of a large amplitude cavitation cycle, as proposed in the Marmottant equation.

  1. radial

    Directory of Open Access Journals (Sweden)

    JOHN WILLIAM BRANCH

    2007-01-01

    Full Text Available La creación de modelos de objetos reales es una tarea compleja para la cual se ha visto que el uso de técnicas tradicionales de modelamiento tiene restricciones. Para resolver algunos de estos problemas, los sensores de rango basados en láser se usan con frecuencia para muestrear la superficie de un objeto desde varios puntos de vista, lo que resulta en un conjunto de imágenes de rango que son registradas e integradas en un modelo final triangulado. En la práctica, debido a las propiedades reflectivas de la superficie, las oclusiones, y limitaciones de acceso, ciertas áreas de la superficie del objeto usualmente no son muestreadas, dejando huecos que pueden crear efectos indeseables en el modelo integrado. En este trabajo, presentamos un nuevo algoritmo para el llenado de huecos a partir de modelos triangulados. El algoritmo comienza localizando la frontera de las regiones donde están los huecos. Un hueco consiste de un camino cerrado de bordes de los triángulos en la frontera que tienen al menos un borde que no es compartido con ningún otro triangulo. El borde del hueco es entonces adaptado mediante un B-Spline donde la variación promedio de la torsión del la aproximación del B-spline es calculada. Utilizando un simple umbral de la variación promedio a lo largo del borde, se puede clasificar automáticamente, entre huecos reales o generados por intervención humana. Siguiendo este proceso de clasificación, se usa entonces una versión automatizada del interpolador de funciones de base radial para llenar el interior del hueco usando los bordes vecinos.

  2. The radial speed-expansion speed relation for Earth-directed CMEs

    Science.gov (United States)

    Mäkelä, P.; Gopalswamy, N.; Yashiro, S.

    2016-05-01

    Earth-directed coronal mass ejections (CMEs) are the main drivers of major geomagnetic storms. Therefore, a good estimate of the disturbance arrival time at Earth is required for space weather predictions. The STEREO and SOHO spacecraft were viewing the Sun in near quadrature during January 2010 to September 2012, providing a unique opportunity to study the radial speed (Vrad)-expansion speed (Vexp) relationship of Earth-directed CMEs. This relationship is useful in estimating the Vrad of Earth-directed CMEs, when they are observed from Earth view only. We selected 19 Earth-directed CMEs observed by the Large Angle and Spectrometric Coronagraph (LASCO)/C3 coronagraph on SOHO and the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI)/COR2 coronagraph on STEREO during January 2010 to September 2012. We found that of the three tested geometric CME models the full ice-cream cone model of the CME describes best the Vrad-Vexp relationship, as suggested by earlier investigations. We also tested the prediction accuracy of the empirical shock arrival (ESA) model proposed by Gopalswamy et al. (2005a), while estimating the CME propagation speeds from the CME expansion speeds. If we use STEREO observations to estimate the CME width required to calculate the Vrad from the Vexp measurements, the mean absolute error (MAE) of the shock arrival times of the ESA model is 8.4 h. If the LASCO measurements are used to estimate the CME width, the MAE still remains below 17 h. Therefore, by using the simple Vrad-Vexp relationship to estimate the Vrad of the Earth-directed CMEs, the ESA model is able to predict the shock arrival times with accuracy comparable to most other more complex models.

  3. PhCESA3 silencing inhibits elongation and stimulates radial expansion in petunia.

    Science.gov (United States)

    Yang, Weiyuan; Cai, Yuanping; Hu, Li; Wei, Qian; Chen, Guoju; Bai, Mei; Wu, Hong; Liu, Juanxu; Yu, Yixun

    2017-02-02

    Cellulose synthase catalytic subunits (CESAs) play important roles in plant growth, development and disease resistance. Previous studies have shown an essential role of Arabidopsis thaliana CESA3 in plant growth. However, little is known about the role of CESA3 in species other than A. thaliana. To gain a better understanding of CESA3, the petunia (Petunia hybrida) PhCESA3 gene was isolated, and the role of PhCESA3 in plant growth was analyzed in a wide range of plants. PhCESA3 mRNA was present at varying levels in tissues examined. VIGS-mediated PhCESA3 silencing resulted in dwarfing of plant height, which was consistent with the phenotype of the A. thaliana rsw1 mutant (a temperature-sensitive allele of AtCESA1), the A. thaliana cev1 mutant (the AtCESA3 mild mutant), and the antisense AtCESA3 line. However, PhCESA3 silencing led to swollen stems, pedicels, filaments, styles and epidermal hairs as well as thickened leaves and corollas, which were not observed in the A. thaliana cev1 mutant, the rsw1 mutant and the antisense AtCESA3 line. Further micrographs showed that PhCESA3 silencing reduced the length and increased the width of cells, suggesting that PhCESA3 silencing inhibits elongation and stimulates radial expansion in petunia.

  4. The effects of stainless steel radial reflector on core reactivity for small modular reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jung Kil, E-mail: jkkang@email.kings.ac.kr; Hah, Chang Joo, E-mail: changhah@kings.ac.kr [KINGS, 658-91, Haemaji-ro, Seosaeng-myeon, Ulju-gun, Ulsan, 689-882 (Korea, Republic of); Cho, Sung Ju, E-mail: sungju@knfc.co.kr; Seong, Ki Bong, E-mail: kbseong@knfc.co.kr [KNFC, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon, 305-353 (Korea, Republic of)

    2016-01-22

    Commercial PWR core is surrounded by a radial reflector, which consists of a baffle and water. Radial reflector is designed to reflect neutron back into the core region to improve the neutron efficiency of the reactor and to protect the reactor vessels from the embrittling effects caused by irradiation during power operation. Reflector also helps to flatten the neutron flux and power distributions in the reactor core. The conceptual nuclear design for boron-free small modular reactor (SMR) under development in Korea requires to have the cycle length of 4∼5 years, rated power of 180 MWth and enrichment less than 5 w/o. The aim of this paper is to analyze the effects of stainless steel radial reflector on the performance of the SMR using UO{sub 2} fuels. Three types of reflectors such as water, water/stainless steel 304 mixture and stainless steel 304 are selected to investigate the effect on core reactivity. Additionally, the thickness of stainless steel and double layer reflector type are also investigated. CASMO-4/SIMULATE-3 code system is used for this analysis. The results of analysis show that single layer stainless steel reflector is the most efficient reflector.

  5. Techniques for computing reactivity changes caused by fuel axial expansion in LMR's

    International Nuclear Information System (INIS)

    Khalil, H.

    1988-01-01

    An evaluation is made of the accuracy of methods used to compute reactivity changes caused by axial fuel relocation in fast reactors. Results are presented to demonstrate the validity of assumptions commonly made such as linearity of reactivity with fuel elongation, additivity of local reactivity contributions, and the adequacy of standard perturbation techniques. Accurate prediction of the reactivity loss caused by axial swelling of metallic fuel is shown to require proper representation of the burnup dependence of the expansion reactivity. Some accuracy limitations in the methods used in transient analyses, which are based on the use of fuel worth tables, are identified, and efficient ways to improve accuracy are described. Implementation of these corrections produced expansion reactivity estimates within 5% of higher-order method for a metal-fueled FFTF core representation. 18 refs., 3 figs., 3 tabs

  6. Radial distribution of power starting from the reactivity using nodal schemes of second and third order

    International Nuclear Information System (INIS)

    Delfin L, A.; Alonso V, G.; Valle G, E. del

    2003-01-01

    In this work two nodal schemes of finite element are presented, one of second and the other of third order of accurate that allow to determine the radial distribution of power starting from the corresponding reactivities.The schemes here developed were obtained taking as starting point the equation developed by Driscoll et al, the one which is based on the diffusion approach of 1-1/2 energy groups. This equation relates the power fraction of an assemble with their reactivity and with the power fractions and reactivities of the assemblies that its surround it. Driscoll and collaborators they solve in form approximate such equation supposing that the reactivity of each assemble it is but a lineal function of the burnt one of the fuel. The spatial approach carries out it with the classic technique of finite differences centered in mesh. Nevertheless that the algebraic system to which its arrive it can be solved without more considerations introduce some additional suppositions and adjustment parameters that it allows them to predict results comparable to those contributed by three dimensions analysis and this way to reduce the one obtained error when its compare their results with those of a production code like CASMO. Also in the two schemes that here are presented the same approaches of Driscoll were used being obtained errors of the one 10% and of 5% for the second schemes and third order respectively for a test case that it was built starting from data of the Cycle 1 of the Unit 1 of the Laguna Verde Nucleo electric plant. These errors its were obtained when comparing with a computer program based on the matrix response method. It is sought to have this way a quick and efficient tool for the multicycle analysis in the fuel management. However, this model presents problems in the appropriate prediction of the average burnt of the nucleus and of the burnt one by lot. (Author)

  7. Radial expansion of the tail current disruption during substorms: A new approach to the substorm onset region

    International Nuclear Information System (INIS)

    Ohtani, S.; Kokubun, S.; Russell, C.T.

    1992-01-01

    The substorm onset region and the radial development of the tail current disruption are examined from a new viewpoint. The reconfiguration of the magnetotail field at substorm onset can be understood in terms of a sudden decrease (disruption) in tail current intensity. The north-south component (B Z ) is very sensitive to whether the spacecraft position is earthward or tailward of the disruption region, while the change in Sun-Earth component (B X ) is most sensitive to the change in tail current intensity near the spacecraft. If the current disruption starts in a localized range of radial distance and expands radially, a distinctive phase relationship between the changes in B X and B Z is expected to be observed. This phase relationship depends on whether the current disruption starts on the earthward side or the tailward side of the spacecraft. Thus it is possible to infer the direction of the radial expansion of the current disruption from magnetic field data of a single spacecraft. This method is applied to ISEE observations of a tail reconfiguration event that occurred on March 6, 1979. The phase relationship indicates that eh disruption region expanded tailward from the earthward side of the spacecraft during the event. This model prediction is consistent with the time lag of magnetic signatures observed by the two ISEE spacecraft. The expansion velocity is estimated at 2 R E /min (∼200 km/s) for this event. Furthermore, it is found that the observed magnetic signatures can be reproduced to a good approximation by a simple geometrical model of the current disruption. The method is used statistically for 13 events selected from the ISEE magnetometer data. It is found that the current disruption usually starts in the near-Earth magnetotail (|X| E ) and often within 15 R E of the Earth

  8. Calculation of the fuel temperature coefficient of reactivity considering non-uniform radial temperature distribution in the fuel rod

    Energy Technology Data Exchange (ETDEWEB)

    Pazirandeh, Ali [Islamic Azad Univ., Tehran (Iran, Islamic Republic of). Science and Research Branch; Hooshyar Mobaraki, Almas

    2017-07-15

    The safe operation of a reactor is based on feedback models. In this paper we attempted to discuss the influence of a non-uniform radial temperature distribution on the fuel rod temperature coefficient of reactivity. The paper demonstrates that the neutron properties of a reactor core is based on effective temperature of the fuel to obtain the correct fuel temperature feedback. The value of volume-averaged temperature being used in the calculations of neutron physics with feedbacks would result in underestimating the probable event. In the calculation it is necessary to use the effective temperature of the fuel in order to provide correct accounting of the fuel temperature feedback. Fuel temperature changes in different zones of the core and consequently reactivity coefficient change are an important parameter for analysis of transient conditions. The restricting factor that compensates the inserted reactivity is the temperature reactivity coefficient and effective delayed neutron fraction.

  9. Magnetic Nulls and Super-radial Expansion in the Solar Corona

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, Sarah E.; Dalmasse, Kevin; Tomczyk, Steven; Toma, Giuliana de; Burkepile, Joan; Galloy, Michael [National Center for Atmospheric Research, 3080 Center Green Drive, Boulder, CO 80301 (United States); Rachmeler, Laurel A. [NASA Marshall Space Flight Center, Huntsville, AL 35811 (United States); Rosa, Marc L. De, E-mail: sgibson@ucar.edu [Lockheed Martin Solar and Astrophysics Laboratory, 3251 Hanover Street B/252, Palo Alto, CA 94304 (United States)

    2017-05-10

    Magnetic fields in the Sun’s outer atmosphere—the corona—control both solar-wind acceleration and the dynamics of solar eruptions. We present the first clear observational evidence of coronal magnetic nulls in off-limb linearly polarized observations of pseudostreamers, taken by the Coronal Multichannel Polarimeter (CoMP) telescope. These nulls represent regions where magnetic reconnection is likely to act as a catalyst for solar activity. CoMP linear-polarization observations also provide an independent, coronal proxy for magnetic expansion into the solar wind, a quantity often used to parameterize and predict the solar wind speed at Earth. We introduce a new method for explicitly calculating expansion factors from CoMP coronal linear-polarization observations, which does not require photospheric extrapolations. We conclude that linearly polarized light is a powerful new diagnostic of critical coronal magnetic topologies and the expanding magnetic flux tubes that channel the solar wind.

  10. Importance of CME Radial Expansion on the Ability of Slow CMEs to Drive Shocks

    Energy Technology Data Exchange (ETDEWEB)

    Lugaz, Noé; Farrugia, Charles J.; Winslow, Reka M. [Space Science Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH (United States); Small, Colin R.; Manion, Thomas [Department of Physics, University of New Hampshire, Durham, NH (United States); Savani, Neel P. [NASA/GSFC and University of Maryland Baltimore County, Greenbelt, MD (United States)

    2017-10-20

    Coronal mass ejections (CMEs) may disturb the solar wind by overtaking it or expanding into it, or both. CMEs whose front moves faster in the solar wind frame than the fast magnetosonic speed drive shocks. Such shocks are important contributors to space weather, by triggering substorms, compressing the magnetosphere, and accelerating particles. In general, near 1 au, CMEs with speed greater than about 500 km s{sup −1} drive shocks, whereas slower CMEs do not. However, CMEs as slow as 350 km s{sup −1} may sometimes, although rarely, drive shocks. Here we study these slow CMEs with shocks and investigate the importance of CME expansion in contributing to their ability to drive shocks and in enhancing shock strength. Our focus is on CMEs with average speeds under 375 km s{sup −1}. From Wind measurements from 1996 to 2016, we find 22 cases of such shock-driving slow CMEs, and for about half of them (11 out of the 22), the existence of the shock appears to be strongly related to CME expansion. We also investigate the proportion of all CMEs with speeds under 500 km s{sup −1} with and without shocks in solar cycles 23 and 24, depending on their speed. We find no systematic difference, as might have been expected on the basis of the lower solar wind and Alfvén speeds reported for solar cycle 24 versus 23. The slower expansion speed of CMEs in solar cycle 24 might be an explanation for this lack of increased frequency of shocks, but further studies are required.

  11. Increased radial glia quiescence, decreased reactivation upon injury and unaltered neuroblast behavior underlie decreased neurogenesis in the aging zebrafish telencephalon.

    Science.gov (United States)

    Edelmann, Kathrin; Glashauser, Lena; Sprungala, Susanne; Hesl, Birgit; Fritschle, Maike; Ninkovic, Jovica; Godinho, Leanne; Chapouton, Prisca

    2013-09-01

    The zebrafish has recently become a source of new data on the mechanisms of neural stem cell (NSC) maintenance and ongoing neurogenesis in adult brains. In this vertebrate, neurogenesis occurs at high levels in all ventricular regions of the brain, and brain injuries recover successfully, owing to the recruitment of radial glia, which function as NSCs. This new vertebrate model of adult neurogenesis is thus advancing our knowledge of the molecular cues in use for the activation of NSCs and fate of their progeny. Because the regenerative potential of somatic stem cells generally weakens with increasing age, it is important to assess the extent to which zebrafish NSC potential decreases or remains unaltered with age. We found that neurogenesis in the ventricular zone, in the olfactory bulb, and in a newly identified parenchymal zone of the telencephalon indeed declines as the fish ages and that oligodendrogenesis also declines. In the ventricular zone, the radial glial cell population remains largely unaltered morphologically but enters less frequently into the cell cycle and hence produces fewer neuroblasts. The neuroblasts themselves do not change their behavior with age and produce the same number of postmitotic neurons. Thus, decreased neurogenesis in the physiologically aging zebrafish brain is correlated with an increasing quiescence of radial glia. After injuries, radial glia in aged brains are reactivated, and the percentage of cell cycle entry is increased in the radial glia population. However, this reaction is far less pronounced than in younger animals, pointing to irreversible changes in aging zebrafish radial glia. Copyright © 2013 Wiley Periodicals, Inc.

  12. Combination of AC Transmission Expansion Planning and Reactive Power Planning in the restructured power system

    International Nuclear Information System (INIS)

    Hooshmand, Rahmat-Allah; Hemmati, Reza; Parastegari, Moein

    2012-01-01

    Highlights: ► To overcome the disadvantages of DC model in Transmission Expansion Planning, AC model should be used. ► The Transmission Expansion Planning associated with Reactive Power Planning results in fewer new transmission lines. ► Electricity market concepts should be considered in Transmission Expansion Planning problem. ► Reliability aspects should be considered in Transmission Expansion Planning problem. ► Particle Swarm Optimization is a suitable optimization method to solve Transmission Expansion Planning problem. - Abstract: Transmission Expansion Planning (TEP) is an important issue in power system studies. It involves decisions on location and number of new transmission lines. Before deregulation of the power system, the goal of TEP problem was investment cost minimization. But in the restructured power system, nodal prices, congestion management, congestion surplus and so on, have been considered too. In this paper, an AC model of TEP problem (AC-TEP) associated with Reactive Power Planning (RPP) is presented. The goals of the proposed planning problem are to minimize investment cost and maximize social benefit at the same time. In the proposed planning problem, in order to improve the reliability of the system the Expected Energy Not Supplied (EENS) index of the system is limited by a constraint. For this purpose, Monte Carlo simulation method is used to determine the EENS. Particle Swarm Optimization (PSO) method is used to solve the proposed planning problem which is a nonlinear mixed integer optimization problem. Simulation results on Garver and RTS systems verify the effectiveness of the proposed planning problem for reduction of the total investment cost, EENS index and also increasing social welfare of the system.

  13. Reactivity variations associated with the core expansion of the MARIA research reactor after modernisation

    International Nuclear Information System (INIS)

    Krzysztoszek, G.

    1997-01-01

    Polish high flux research reactor MARIA is a pool type reactor moderated with beryllium and water and cooled with water. The fuel is 80% enriched uranium, in the shape of multitube fuel elements, each tube made up of UAl x alloy in aluminium cladding. MARIA reactor has been operated in the years of 1977-85 and then it was modernised and again put into operation in December 1992. The modernisation as regarded the reactor core comprises a beryllium matrix expansion from 20-48 blocks. Within the frame of the power start-up and trial operation the reactor has been extended from 12 to 18 fuel channels. On that stage of reactor operation the power of mostly loaded fuel channels was constrained to 1,6 MW. Reactor has been operated within the 100-hrs campaign for an irradiation of target materials and for performing measurements at the horizontal channel outlets. In the previous time it has been noticed substantial differences in reactivity changes of the core in similar campaigns of reactor operation. It concerns the reactivity losses during poisoning period of the reactor within the first 30-40 hrs of operation as well as in the fuel burning up process. An analysis of the reactivity variations during the core extension will made possible the fuel management optimisation in further reactor operation system. (author)

  14. Mineralogy, geochemistry and expansion testing of an alkali-reactive basalt from western Anatolia, Turkey

    International Nuclear Information System (INIS)

    Copuroglu, Oguzhan; Andic-Cakir, Ozge; Broekmans, Maarten A.T.M.; Kuehnel, Radko

    2009-01-01

    In this paper, the alkali-silica reaction performance of a basalt rock from western Anatolia, Turkey is reported. It is observed that the rock causes severe gel formation in the concrete microbar test. It appears that the main source of expansion is the reactive glassy phase of the basalt matrix having approximately 70% of SiO 2 . The study presents the microstructural characteristics of unreacted and reacted basalt aggregate by optical and electron microscopy and discusses the possible reaction mechanism. Microstructural analysis revealed that the dissolution of silica is overwhelming in the matrix of the basalt and it eventually generates four consequences: (1) Formation of alkali-silica reaction gel at the aggregate perimeter, (2) increased porosity and permeability of the basalt matrix, (3) reduction of mechanical properties of the aggregate and (4) additional gel formation within the aggregate. It is concluded that the basalt rock is highly prone to alkali-silica reaction. As an aggregate, this rock is not suitable for concrete production.

  15. Mineralogy, geochemistry and expansion testing of an alkali-reactive basalt from western Anatolia, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Copuroglu, Oguzhan, E-mail: O.Copuroglu@CiTG.TUDelft.NL [Delft University of Technology, Faculty of CiTG, Materials and Environment, Stevinweg 1, 2628CN, Delft (Netherlands); Andic-Cakir, Ozge [Ege University, Civil Engineering Dept., 35100 Bornova, Izmir (Turkey); Broekmans, Maarten A.T.M. [Geological Survey of Norway, Dept. of Mineral Characterization, N-7491 Trondheim (Norway); Kuehnel, Radko [Burgemeester Merkusstraat 5, 2645 NJ, Delfgauw (Netherlands)

    2009-07-15

    In this paper, the alkali-silica reaction performance of a basalt rock from western Anatolia, Turkey is reported. It is observed that the rock causes severe gel formation in the concrete microbar test. It appears that the main source of expansion is the reactive glassy phase of the basalt matrix having approximately 70% of SiO{sub 2}. The study presents the microstructural characteristics of unreacted and reacted basalt aggregate by optical and electron microscopy and discusses the possible reaction mechanism. Microstructural analysis revealed that the dissolution of silica is overwhelming in the matrix of the basalt and it eventually generates four consequences: (1) Formation of alkali-silica reaction gel at the aggregate perimeter, (2) increased porosity and permeability of the basalt matrix, (3) reduction of mechanical properties of the aggregate and (4) additional gel formation within the aggregate. It is concluded that the basalt rock is highly prone to alkali-silica reaction. As an aggregate, this rock is not suitable for concrete production.

  16. Anisotropic expansion of Pu through the α-β-γ phase transitions while under radial compressive stress

    Science.gov (United States)

    Spearing, Dane R.; Veirs, D. Kirk; Prenger, F. Coyne

    2000-07-01

    In support of the new US Department of Energy (DOE) standard for the stabilization, packaging, and storage of plutonium bearing materials, the effects of the volume expansion associated with the α/β and β/γ transformations of Pu metal on the integrity of a stainless steel storage container were examined.

  17. Unsteady rans simulation of the off-design operation of a high expansion ratio ORC radial turbine

    NARCIS (Netherlands)

    Rinaldi, E.; Pecnik, R.; Colonna di Paliano, P.

    2015-01-01

    The design of Organic Rankine cycle (ORC) turbines is a challenging task due to the complex thermodynamic behavior of the working fluid, the typical high expansion ratio which leads to a highly supersonic flow, the flow unsteadiness, and the continuous shift of operation between on- and off-design

  18. Alteration of alkali reactive aggregates autoclaved in different alkali solutions and application to alkali-aggregate reaction in concrete (II) expansion and microstructure of concrete microbar

    International Nuclear Information System (INIS)

    Lu Duyou; Mei Laibao; Xu Zhongzi; Tang Mingshu; Mo Xiangyin; Fournier, Benoit

    2006-01-01

    The effect of the type of alkalis on the expansion behavior of concrete microbars containing typical aggregate with alkali-silica reactivity and alkali-carbonate reactivity was studied. The results verified that: (1) at the same molar concentration, sodium has the strongest contribution to expansion due to both ASR and ACR, followed by potassium and lithium; (2) sufficient LiOH can completely suppress expansion due to ASR whereas it can induce expansion due to ACR. It is possible to use the duplex effect of LiOH on ASR and ACR to clarify the ACR contribution when ASR and ACR may coexist. It has been shown that a small amount of dolomite in the fine-grained siliceous Spratt limestone, which has always been used as a reference aggregate for high alkali-silica reactivity, might dedolomitize in alkaline environment and contribute to the expansion. That is to say, Spratt limestone may exhibit both alkali-silica and alkali-carbonate reactivity, although alkali-silica reactivity is predominant. Microstructural study suggested that the mechanism in which lithium controls ASR expansion is mainly due to the favorable formation of lithium-containing less-expansive product around aggregate particles and the protection of the reactive aggregate from further attack by alkalis by the lithium-containing product layer

  19. Radial distribution of power starting from the reactivity using nodal schemes of second and third order; Distribucion radial de potencia a partir de la reactividad usando esquemas nodales de segundo y tercer orden

    Energy Technology Data Exchange (ETDEWEB)

    Delfin L, A.; Alonso V, G. [ININ, Km. 36.5 Carretera Mexico-Toluca, 52045 Ocoyocac, Estado de Mexico (Mexico); Valle G, E. del [IPN-ESFM, 07738 Mexico D.F. (Mexico)]. e-mail: adl@nuclear.inin.mx

    2003-07-01

    In this work two nodal schemes of finite element are presented, one of second and the other of third order of accurate that allow to determine the radial distribution of power starting from the corresponding reactivities.The schemes here developed were obtained taking as starting point the equation developed by Driscoll et al, the one which is based on the diffusion approach of 1-1/2 energy groups. This equation relates the power fraction of an assemble with their reactivity and with the power fractions and reactivities of the assemblies that its surround it. Driscoll and collaborators they solve in form approximate such equation supposing that the reactivity of each assemble it is but a lineal function of the burnt one of the fuel. The spatial approach carries out it with the classic technique of finite differences centered in mesh. Nevertheless that the algebraic system to which its arrive it can be solved without more considerations introduce some additional suppositions and adjustment parameters that it allows them to predict results comparable to those contributed by three dimensions analysis and this way to reduce the one obtained error when its compare their results with those of a production code like CASMO. Also in the two schemes that here are presented the same approaches of Driscoll were used being obtained errors of the one 10% and of 5% for the second schemes and third order respectively for a test case that it was built starting from data of the Cycle 1 of the Unit 1 of the Laguna Verde Nucleo electric plant. These errors its were obtained when comparing with a computer program based on the matrix response method. It is sought to have this way a quick and efficient tool for the multicycle analysis in the fuel management. However, this model presents problems in the appropriate prediction of the average burnt of the nucleus and of the burnt one by lot. (Author)

  20. Phase transition and thermal expansion studies of alumina thin films prepared by reactive pulsed laser deposition.

    Science.gov (United States)

    Balakrishnan, G; Thirumurugesan, R; Mohandas, E; Sastikumar, D; Kuppusami, P; Songl, J I

    2014-10-01

    Aluminium oxide (Al2O3) thin films were deposited on Si (100) substrates at an optimized oxygen partial pressure of 3 x 10(-3) mbar at room temperature by pulsed laser deposition (PLD). The films were characterized by high temperature X-ray diffraction (HTXRD), field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The HTXRD pattern showed the cubic y-Al2O3 phase in the temperature range 300-973 K. At temperatures ≥ 1073 K, the δ and θ-phases of Al2O3 were observed. The mean linear thermal expansion coefficient and volume thermal expansion coefficient of γ-Al2O3 was found to be 12.66 x 10(-6) K(-1) and 38.87 x 10(-6) K(-1) in the temperature range 300 K-1073 K. The field emission scanning electron microscopy revealed a smooth and structureless morphology of the films deposited on Si (100). The atomic force microscopy study indicated the increased crystallinity and surface roughness of the films after annealing at high temperature.

  1. Expansion of donor-reactive host T cells in primary graft failure after allogeneic hematopoietic SCT following reduced-intensity conditioning.

    Science.gov (United States)

    Koyama, M; Hashimoto, D; Nagafuji, K; Eto, T; Ohno, Y; Aoyama, K; Iwasaki, H; Miyamoto, T; Hill, G R; Akashi, K; Teshima, T

    2014-01-01

    Graft rejection remains a major obstacle in allogeneic hematopoietic SCT following reduced-intensity conditioning (RIC-SCT), particularly after cord blood transplantation (CBT). In a murine MHC-mismatched model of RIC-SCT, primary graft rejection was associated with activation and expansion of donor-reactive host T cells in peripheral blood and BM early after SCT. Donor-derived dendritic cells are at least partly involved in host T-cell activation. We then evaluated if such an expansion of host T cells could be associated with graft rejection after RIC-CBT. Expansion of residual host lymphocytes was observed in 4/7 patients with graft rejection at 3 weeks after CBT, but in none of the 17 patients who achieved engraftment. These results suggest the crucial role of residual host T cells after RIC-SCT in graft rejection and expansion of host T cells could be a marker of graft rejection. Development of more efficient T cell-suppressive conditioning regimens may be necessary in the context of RIC-SCT.

  2. Expansion of mycobacterium-reactive gamma delta T cells by a subset of memory helper T cells.

    Science.gov (United States)

    Vila, L M; Haftel, H M; Park, H S; Lin, M S; Romzek, N C; Hanash, S M; Holoshitz, J

    1995-04-01

    Human gamma delta T cells expressing the V gamma 9/V delta 2 T-cell receptor have been previously found to proliferate in response to certain microorganisms and to expand throughout life, presumably because of extrathymic activation by foreign antigens. In vitro expansion of V gamma 9/V delta 2 cells by mycobacteria has been previously shown to be dependent on accessory cells. In order to gain an insight into the mechanisms involved in the expansion of these cells, we have undertaken to identify the peripheral blood subset of cells on which proliferation of V gamma 9/V delta 2 cells in response to mycobacteria is dependent. Contrary to their role in antigen presentation to alpha beta T cells, professional antigen-presenting cells, such as monocytes, B cells, and dendritic cells, were unable to provide the cellular support for the expansion of V gamma 9/V delta 2 cells. Selective depletion of T-cell subsets, as well as the use of highly purified T-cell populations, indicated that the only subset of peripheral blood cells that could expand V gamma 9/V delta 2 cells were CD4+ CD45RO+ CD7- alpha beta T cells. These cells underwent distinct intracellular signaling events after stimulation with the mycobacterial antigen. Expansion of V gamma 9/V delta 2 cells by alpha beta T cells was dependent on cell-cell contact. This is the first evidence that a small subset of the memory helper T-cell population is exclusively responsible for the peripheral expansion of V gamma 9/V delta 2 cells. These data illustrate a unique aspect of antigen recognition by gamma delta T cells and provide new means to study their immune defense role.

  3. Reactivity feedback models for SSC-K

    Energy Technology Data Exchange (ETDEWEB)

    Han, Do Hee; Kwon, Young Min; Kim, Kyung Du; Chang, Won Pyo [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-06-01

    Safety of KALIMER is assured by the inherent safety of the core and passive safety of the safety-related systems. For the safety analysis of a new reactor design such as KALIMER, analysis models, which are consistent with the design, have to be developed for a plant-wide transient and safety analysis code. Efforts for the development of reactivity feedback models for SSC-K, which is now being developed for the safety analysis of KALIMER, is described in this report. Models for Doppler, sodium density/void, fuel axial expansion, core radial expansion, and CRDL expansion have been developed. Test runs have been performed for the unprotected accident for the verification of the models. Use of KALIMER reactivity coefficients and future development of models for GEM and PSDRS would make it possible to analyze the response of KALIMER under TOP as well as LOF and LOHS accident conditions using SSC-K. (author). 5 refs., 64 figs., 2 tabs.

  4. Tolerance without clonal expansion: self-antigen-expressing B cells program self-reactive T cells for future deletion.

    Science.gov (United States)

    Frommer, Friederike; Heinen, Tobias J A J; Wunderlich, F Thomas; Yogev, Nir; Buch, Thorsten; Roers, Axel; Bettelli, Estelle; Müller, Werner; Anderton, Stephen M; Waisman, Ari

    2008-10-15

    B cells have been shown in various animal models to induce immunological tolerance leading to reduced immune responses and protection from autoimmunity. We show that interaction of B cells with naive T cells results in T cell triggering accompanied by the expression of negative costimulatory molecules such as PD-1, CTLA-4, B and T lymphocyte attenuator, and CD5. Following interaction with B cells, T cells were not induced to proliferate, in a process that was dependent on their expression of PD-1 and CTLA-4, but not CD5. In contrast, the T cells became sensitive to Ag-induced cell death. Our results demonstrate that B cells participate in the homeostasis of the immune system by ablation of conventional self-reactive T cells.

  5. Bearing-Mounting Concept Accommodates Thermal Expansion

    Science.gov (United States)

    Nespodzany, Robert; Davis, Toren S.

    1995-01-01

    Pins or splines allow radial expansion without slippage. Design concept for mounting rotary bearing accommodates differential thermal expansion between bearing and any structure(s) to which bearing connected. Prevents buildup of thermal stresses by allowing thermal expansion to occur freely but accommodating expansion in such way not to introduce looseness. Pin-in-slot configuration also maintains concentricity.

  6. Radial nerve dysfunction

    Science.gov (United States)

    Neuropathy - radial nerve; Radial nerve palsy; Mononeuropathy ... Damage to one nerve group, such as the radial nerve, is called mononeuropathy . Mononeuropathy means there is damage to a single nerve. Both ...

  7. AUTO-EXPANSIVE FLOW

    Science.gov (United States)

    Physics suggests that the interplay of momentum, continuity, and geometry in outward radial flow must produce density and concomitant pressure reductions. In other words, this flow is intrinsically auto-expansive. It has been proposed that this process is the key to understanding...

  8. Short-term vitamin E treatment impairs reactive oxygen species signaling required for adipose tissue expansion, resulting in fatty liver and insulin resistance in obese mice.

    Directory of Open Access Journals (Sweden)

    Martin Alcala

    Full Text Available The use of antioxidant therapy in the treatment of oxidative stress-related diseases such as cardiovascular disease, diabetes or obesity remains controversial. Our aim is to demonstrate that antioxidant supplementation may promote negative effects if used before the establishment of oxidative stress due to a reduced ROS generation under physiological levels, in a mice model of obesity.C57BL/6J mice were fed with a high-fat diet for 14 weeks, with (OE group or without (O group vitamin E supplementation.O mice developed a mild degree of obesity, which was not enough to induce metabolic alterations or oxidative stress. These animals exhibited a healthy expansion of retroperitoneal white adipose tissue (rpWAT and the liver showed no signs of lipotoxicity. Interestingly, despite achieving a similar body weight, OE mice were insulin resistant. In the rpWAT they presented a reduced generation of ROS, even below physiological levels (C: 1651.0 ± 212.0; O: 3113 ± 284.7; OE: 917.6 ±104.4 RFU/mg protein. C vs OE p< 0.01. ROS decay may impair their action as second messengers, which could account for the reduced adipocyte differentiation, lipid transport and adipogenesis compared to the O group. Together, these processes limited the expansion of this fat pad and as a consequence, lipid flux shifted towards the liver, causing steatosis and hepatomegaly, which may contribute to the marked insulin resistance.This study provides in vivo evidence for the role of ROS as second messengers in adipogenesis, lipid metabolism and insulin signaling. Reducing ROS generation below physiological levels when the oxidative process has not yet been established may be the cause of the controversial results obtained by antioxidant therapy.

  9. A study of temperature coefficients of reactivity for a Savannah River Site tritium-producing charge

    International Nuclear Information System (INIS)

    George, D.L.; Frost, R.L.

    1991-01-01

    Temperature coefficients of reactivity have been calculated for the Mark 22 assembly in the K-14 charge at the Savannah River Site. Temperature coefficients are the most important reactivity feedback mechanism in SRS reactors; they are used in all safety analyses performed in support of the Safety Analysis Report, and in operations to predict reactivity changes with control rod moves. The effects of the radial location of the assembly in the reactor, isotope depletion, and thermal expansion of the metal components on the temperature coefficients have also been investigated. With the exception of the dead space coefficient, all of the regional temperature coefficients were found to be negative or zero. All of the temperature coefficients become more negative with isotopic depletion over the fuel cycle. Coefficients also become more negative with increasing radial distance of the assembly from the center of the core; this is proven from first principles and confirmed by calculations. It was found that axial and radial thermal expansion effects on the metal fuel and target tubes counteract one another, indicating these effects do not need to be considered in future temperature coefficient calculations for the Mark 22 assembly. The moderator coefficient was found to be nonlinear with temperature; thus, the values derived for accidents involving increases in moderator temperature are significantly different than those for decreases in moderator temperature, although the moderator coefficient is always negative

  10. Radial nerve dysfunction (image)

    Science.gov (United States)

    The radial nerve travels down the arm and supplies movement to the triceps muscle at the back of the upper arm. ... the wrist and hand. The usual causes of nerve dysfunction are direct trauma, prolonged pressure on the ...

  11. Fast Flux Test Facility (FFTF) feedback reactivity components

    International Nuclear Information System (INIS)

    Nguyen, D.H.

    1988-04-01

    The static tests conducted during Cycle 8A (1986) of the FFTF have allowed, for the first time, the experimental determination of each of the feedback reactivities caused by the following mechanisms: fuel axial expansion, control rod repositioning, core radial expansion, and subassembly bowing. A semiempirical equation was obtained to describe each of these feedback components that depended only on the relevant reactor temperature (bowing was presented in a tabular form). The Doppler and sodium density reactivities were calculated using existing mechanistic methods. Although they could also be fitted with closed-form equations depending only on temperatures, these equations are not needed in transient analyses using whole core safety computer codes, which use mechanistic methods. The static feedback reactivity model was extended to obtain a dynamic model via the concept of ''time constants.'' Besides being used for transient analyses in the FFTF, these feedback equations constitute a database for the validation and/or calibration of mechanistic feedback reactivity models. 2 refs., 6 tabs

  12. Thermal expansion

    International Nuclear Information System (INIS)

    Yun, Y.

    2015-01-01

    Thermal expansion of fuel pellet is an important property which limits the lifetime of the fuels in reactors, because it affects both the pellet and cladding mechanical interaction and the gap conductivity. By fitting a number of available measured data, recommended equations have been presented and successfully used to estimate thermal expansion coefficient of the nuclear fuel pellet. However, due to large scatter of the measured data, non-consensus data have been omitted in formulating the equations. Also, the equation is strongly governed by the lack of appropriate experimental data. For those reasons, it is important to develop theoretical methodologies to better describe thermal expansion behaviour of nuclear fuel. In particular, first-principles and molecular dynamics simulations have been certainly contributed to predict reliable thermal expansion without fitting the measured data. Furthermore, the two theoretical techniques have improved on understanding the change of fuel dimension by describing the atomic-scale processes associated with lattice expansion in the fuels. (author)

  13. Radial cracks and fracture mechanism of radially oriented ring 2:17 type SmCo magnets

    International Nuclear Information System (INIS)

    Tian Jianjun; Pan Dean; Zhou Hao; Yin Fuzheng; Tao Siwu; Zhang Shengen; Qu Xuanhui

    2009-01-01

    Radially oriented ring 2:17 type SmCo magnets have different microstructure in the radial direction (easy magnetization) and axial direction (hard magnetization). The structure of the cross-section in radial direction is close-packed atomic plane, which shows cellular microstructure. The microstructure of the cross-section in axial direction consists of a mixture of rhombic microstructure and parallel lamella phases. So the magnets have obvious anisotropy of thermal expansion in different directions. The difference of the thermal expansion coefficients reaches the maximum value at 830-860 deg. C, which leads to radial cracks during quenching. The magnets have high brittlement because there are fewer slip systems in crystal structure. The fracture is brittle cleavage fracture.

  14. Radial wedge flange clamp

    Science.gov (United States)

    Smith, Karl H.

    2002-01-01

    A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

  15. Sirenomelia with radial dysplasia.

    Science.gov (United States)

    Kulkarni, M L; Abdul Manaf, K M; Prasannakumar, D G; Kulkarni, Preethi M

    2004-05-01

    Sirenomelia is a rare anomaly usually associated with other multiple malformations. In this communication the authors report a case of sirenomelia associated with multiple malformations, which include radial hypoplasia also. Though several theories have been proposed regarding the etiology of multiple malformation syndromes in the past, the recent theory of primary developmental defect during blastogenesis holds good in this case.

  16. Radially truncated galactic discs

    NARCIS (Netherlands)

    Grijs, R. de; Kregel, M.; Wesson, K H

    2000-01-01

    Abstract: We present the first results of a systematic analysis of radially truncatedexponential discs for four galaxies of a sample of disc-dominated edge-onspiral galaxies. Edge-on galaxies are very useful for the study of truncatedgalactic discs, since we can follow their light distributions out

  17. Variable stator radial turbine

    Science.gov (United States)

    Rogo, C.; Hajek, T.; Chen, A. G.

    1984-01-01

    A radial turbine stage with a variable area nozzle was investigated. A high work capacity turbine design with a known high performance base was modified to accept a fixed vane stagger angle moveable sidewall nozzle. The nozzle area was varied by moving the forward and rearward sidewalls. Diffusing and accelerating rotor inlet ramps were evaluated in combinations with hub and shroud rotor exit rings. Performance of contoured sidewalls and the location of the sidewall split line with respect to the rotor inlet was compared to the baseline. Performance and rotor exit survey data are presented for 31 different geometries. Detail survey data at the nozzle exit are given in contour plot format for five configurations. A data base is provided for a variable geometry concept that is a viable alternative to the more common pivoted vane variable geometry radial turbine.

  18. Estimation of Radial Runout

    OpenAIRE

    Nilsson, Martin

    2007-01-01

    The demands for ride comfort quality in today's long haulage trucks are constantly growing. A part of the ride comfort problems are represented by internal vibrations caused by rotating mechanical parts. This thesis work focus on the vibrations generated from radial runout on the wheels. These long haulage trucks travel long distances on smooth highways, with a constant speed of 90 km/h resulting in a 7 Hz oscillation. This frequency creates vibrations in the cab, which can be found annoying....

  19. Radial Fuzzy Systems

    Czech Academy of Sciences Publication Activity Database

    Coufal, David

    2017-01-01

    Roč. 319, 15 July (2017), s. 1-27 ISSN 0165-0114 R&D Projects: GA MŠk(CZ) LD13002 Institutional support: RVO:67985807 Keywords : fuzzy systems * radial functions * coherence Subject RIV: BA - General Mathematics OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 2.718, year: 2016

  20. Radial Field Piezoelectric Diaphragms

    Science.gov (United States)

    Bryant, R. G.; Effinger, R. T., IV; Copeland, B. M., Jr.

    2002-01-01

    A series of active piezoelectric diaphragms were fabricated and patterned with several geometrically defined Inter-Circulating Electrodes "ICE" and Interdigitated Ring Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is a radially distributed electric field that mechanically strains the piezoceramic along the Z-axis (perpendicular to the applied electric field). Unlike other piezoelectric bender actuators, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements (several times that of the equivalent Unimorph) while maintaining a constant circumference. One of the more intriguing aspects is that the radial strain field reverses itself along the radius of the RFD while the tangential strain remains relatively constant. The result is a Z-deflection that has a conical profile. This paper covers the fabrication and characterization of the 5 cm. (2 in.) diaphragms as a function of poling field strength, ceramic thickness, electrode type and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage at low frequencies. The unique features of these RFDs include the ability to be clamped about their perimeter with little or no change in displacement, the environmentally insulated packaging, and a highly repeatable fabrication process that uses commodity materials.

  1. Perceived radial translation during centrifugation

    NARCIS (Netherlands)

    Bos, J.E.; Correia Grácio, B.J.

    2015-01-01

    BACKGROUND: Linear acceleration generally gives rise to translation perception. Centripetal acceleration during centrifugation, however, has never been reported giving rise to a radial, inward translation perception. OBJECTIVE: To study whether centrifugation can induce a radial translation

  2. Expansion dynamics

    International Nuclear Information System (INIS)

    Knoll, J.

    1985-10-01

    A quantum dynamical model is suggested which describes the expansion and disassembly phase of highly excited compounds formed in energetic heavy-ion collisions. First applications in two space and one time dimensional model world are discussed and qualitatively compared to standard freeze-out concepts. (orig.)

  3. expansion method

    Indian Academy of Sciences (India)

    of a system under investigation is to model the system in terms of some ... The organization of the paper is as follows: In §2, a brief account of the (G /G)- expansion ...... It is interesting to note that from the general results, one can easily recover.

  4. Radial reflection diffraction tomography

    Science.gov (United States)

    Lehman, Sean K.

    2012-12-18

    A wave-based tomographic imaging method and apparatus based upon one or more rotating radially outward oriented transmitting and receiving elements have been developed for non-destructive evaluation. At successive angular locations at a fixed radius, a predetermined transmitting element can launch a primary field and one or more predetermined receiving elements can collect the backscattered field in a "pitch/catch" operation. A Hilbert space inverse wave (HSIW) algorithm can construct images of the received scattered energy waves using operating modes chosen for a particular application. Applications include, improved intravascular imaging, bore hole tomography, and non-destructive evaluation (NDE) of parts having existing access holes.

  5. Radial semiconductor drift chambers

    International Nuclear Information System (INIS)

    Rawlings, K.J.

    1987-01-01

    The conditions under which the energy resolution of a radial semiconductor drift chamber based detector system becomes dominated by the step noise from the detector dark current have been investigated. To minimise the drift chamber dark current attention should be paid to carrier generation at Si/SiO 2 interfaces. This consideration conflicts with the desire to reduce the signal risetime: a higher drift field for shorter signal pulses requires a larger area of SiO 2 . Calculations for the single shaping and pseudo Gaussian passive filters indicate that for the same degree of signal risetime sensitivity in a system dominated by the step noise from the detector dark current, the pseudo Gaussian filter gives only a 3% improvement in signal/noise and 12% improvement in rate capability compared with the single shaper performance. (orig.)

  6. ISR Radial Field Magnet

    CERN Multimedia

    1983-01-01

    There were 37 (normal) + 3 (special) Radial Field magnets in the ISR to adjust vertically the closed orbit. Gap heights and strengths were 200 mm and .12 Tm in the normal magnets, 220 mm and .18 Tm in the special ones. The core length was 430 mm in both types. Due to their small length as compared to the gap heights the end fringe field errors were very important and had to be compensated by suitably shaping the poles. In order to save on cables, as these magnets were located very far from their power supplies, the coils of the normal type magnets were formed by many turns of solid cpper conductor with some interleaved layers of hollow conductor directly cooled by circulating water

  7. The ARCS radial collimator

    International Nuclear Information System (INIS)

    Stone, M.B.; Abernathy, D.L.; Niedziela, J.L.; Overbay, M.A.

    2015-01-01

    We have designed, installed, and commissioned a scattered beam radial collimator for use at the ARCS Wide Angular Range Chopper Spectrometer at the Spallation Neutron Source. The collimator has been designed to work effectively for thermal and epithermal neutrons and with a range of sample environments. Other design considerations include the accommodation of working within a high vacuum environment and having the ability to quickly install and remove the collimator from the scattered beam. The collimator is composed of collimating blades (or septa). The septa are 12 micron thick Kapton foils coated on each side with 39 microns of enriched boron carbide ( 10 B 4 C with 10 B > 96%) in an ultra-high vacuum compatible binder. The collimator blades represent an additional 22 m 2 of surface area. In the article we present collimator's design and performance and methodologies for its effective use

  8. Moment methods with effective nuclear Hamiltonians; calculations of radial moments

    International Nuclear Information System (INIS)

    Belehrad, R.H.

    1981-02-01

    A truncated orthogonal polynomial expansion is used to evaluate the expectation value of the radial moments of the one-body density of nuclei. The expansion contains the configuration moments, , , and 2 >, where R/sup (k)/ is the operator for the k-th power of the radial coordinate r, and H is the effective nuclear Hamiltonian which is the sum of the relative kinetic energy operator and the Bruckner G matrix. Configuration moments are calculated using trace reduction formulae where the proton and neutron orbitals are treated separately in order to find expectation values of good total isospin. The operator averages are taken over many-body shell model states in the harmonic oscillator basis where all particles are active and single-particle orbitals through six major shells are included. The radial moment expectation values are calculated for the nuclei 16 O, 40 Ca, and 58 Ni and find that is usually the largest term in the expansion giving a large model space dependence to the results. For each of the 3 nuclei, a model space is found which gives the desired rms radius and then we find that the other 5 lowest moments compare favorably with other theoretical predictions. Finally, we use a method of Gordon (5) to employ the lowest 6 radial moment expectation values in the calculation of elastic electron scattering from these nuclei. For low to moderate momentum transfer, the results compare favorably with the experimental data

  9. TESTING THE EFFECTS OF EXPANSION ON SOLAR WIND TURBULENCE

    International Nuclear Information System (INIS)

    Vech, Daniel; Chen, Christopher H K

    2016-01-01

    We present a multi-spacecraft approach to test the predictions of recent studies on the effect of solar wind expansion on the radial spectral, variance, and local 3D anisotropies of the turbulence. We found that on small scales (5000–10,000 km) the power levels of the B-trace structure functions do not depend on the sampling direction with respect to the radial suggesting that on this scale the effect of expansion is small possibly due to fast turbulent timescales. On larger scales (110–135 R E ), the fluctuations of the radial magnetic field component are reduced by ∼20% compared to the transverse (perpendicular to radial) ones, which could be due to expansion confining the fluctuations into the plane perpendicular to radial. For the local 3D spectral anisotropy, the B-trace structure functions showed dependence on the sampling direction with respect to radial. The anisotropy in the perpendicular plane is reduced when the increments are taken perpendicular with respect to radial, which could be an effect of expansion.

  10. TESTING THE EFFECTS OF EXPANSION ON SOLAR WIND TURBULENCE

    Energy Technology Data Exchange (ETDEWEB)

    Vech, Daniel; Chen, Christopher H K, E-mail: dvech@umich.edu [Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom)

    2016-11-20

    We present a multi-spacecraft approach to test the predictions of recent studies on the effect of solar wind expansion on the radial spectral, variance, and local 3D anisotropies of the turbulence. We found that on small scales (5000–10,000 km) the power levels of the B-trace structure functions do not depend on the sampling direction with respect to the radial suggesting that on this scale the effect of expansion is small possibly due to fast turbulent timescales. On larger scales (110–135 R{sub E}), the fluctuations of the radial magnetic field component are reduced by ∼20% compared to the transverse (perpendicular to radial) ones, which could be due to expansion confining the fluctuations into the plane perpendicular to radial. For the local 3D spectral anisotropy, the B-trace structure functions showed dependence on the sampling direction with respect to radial. The anisotropy in the perpendicular plane is reduced when the increments are taken perpendicular with respect to radial, which could be an effect of expansion.

  11. Antiproton compression and radial measurements

    CERN Document Server

    Andresen, G B; Bowe, P D; Bray, C C; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Fajans, J; Fujiwara, M C; Funakoshi, R; Gill, D R; Hangst, J S; Hardy, W N; Hayano, R S; Hayden, M E; Humphries, A J; Hydomako, R; Jenkins, M J; Jorgensen, L V; Kurchaninov, L; Lambo, R; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Page R D; Povilus, A; Pusa, P; Robicheaux, F; Sarid, E; Seif El Nasr, S; Silveira, D M; Storey, J W; Thompson, R I; Van der Werf, D P; Wurtele, J S; Yamazaki, Y

    2008-01-01

    Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, achieved by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile, and its relation to that of the electron plasma. We also measure the outer radial profile by ejecting antiprotons to the trap wall using an octupole magnet.

  12. Radial Domany-Kinzel models with mutation and selection

    Science.gov (United States)

    Lavrentovich, Maxim O.; Korolev, Kirill S.; Nelson, David R.

    2013-01-01

    We study the effect of spatial structure, genetic drift, mutation, and selective pressure on the evolutionary dynamics in a simplified model of asexual organisms colonizing a new territory. Under an appropriate coarse-graining, the evolutionary dynamics is related to the directed percolation processes that arise in voter models, the Domany-Kinzel (DK) model, contact process, and so on. We explore the differences between linear (flat front) expansions and the much less familiar radial (curved front) range expansions. For the radial expansion, we develop a generalized, off-lattice DK model that minimizes otherwise persistent lattice artifacts. With both simulations and analytical techniques, we study the survival probability of advantageous mutants, the spatial correlations between domains of neutral strains, and the dynamics of populations with deleterious mutations. “Inflation” at the frontier leads to striking differences between radial and linear expansions. For a colony with initial radius R0 expanding at velocity v, significant genetic demixing, caused by local genetic drift, occurs only up to a finite time t*=R0/v, after which portions of the colony become causally disconnected due to the inflating perimeter of the expanding front. As a result, the effect of a selective advantage is amplified relative to genetic drift, increasing the survival probability of advantageous mutants. Inflation also modifies the underlying directed percolation transition, introducing novel scaling functions and modifications similar to a finite-size effect. Finally, we consider radial range expansions with deflating perimeters, as might arise from colonization initiated along the shores of an island.

  13. Radial gas turbine design

    Energy Technology Data Exchange (ETDEWEB)

    Krausche, S.; Ohlsson, Johan

    1998-04-01

    The objective of this work was to develop a program dealing with design point calculations of radial turbine machinery, including both compressor and turbine, with as few input data as possible. Some simple stress calculations and turbine metal blade temperatures were also included. This program was then implanted in a German thermodynamics program, Gasturb, a program calculating design and off-design performance of gas turbines. The calculations proceed with a lot of assumptions, necessary to finish the task, concerning pressure losses, velocity distribution, blockage, etc., and have been correlated with empirical data from VAT. Most of these values could have been input data, but to prevent the user of the program from drowning in input values, they are set as default values in the program code. The output data consist of geometry, Mach numbers, predicted component efficiency etc., and a number of graphical plots of geometry and velocity triangles. For the cases examined, the error in predicted efficiency level was within {+-} 1-2% points, and quite satisfactory errors in geometrical and thermodynamic conditions were obtained Examination paper. 18 refs, 36 figs

  14. Radial flow heat exchanger

    Science.gov (United States)

    Valenzuela, Javier

    2001-01-01

    A radial flow heat exchanger (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat exchangers may be stacked to achieve a modular heat exchange assembly (300). Certain heat exchangers in the assembly may be designed slightly differently than other heat exchangers to address changes in fluid properties during transport through the heat exchanger, so as to enhance overall thermal effectiveness of the assembly.

  15. Stability of radial swirl flows

    International Nuclear Information System (INIS)

    Dou, H S; Khoo, B C

    2012-01-01

    The energy gradient theory is used to examine the stability of radial swirl flows. It is found that the flow of free vortex is always stable, while the introduction of a radial flow will induce the flow to be unstable. It is also shown that the pure radial flow is stable. Thus, there is a flow angle between the pure circumferential flow and the pure radial flow at which the flow is most unstable. It is demonstrated that the magnitude of this flow angle is related to the Re number based on the radial flow rate, and it is near the pure circumferential flow. The result obtained in this study is useful for the design of vaneless diffusers of centrifugal compressors and pumps as well as other industrial devices.

  16. Radial Flow in a Multiphase Transport Model at FAIR Energies

    Directory of Open Access Journals (Sweden)

    Soumya Sarkar

    2018-01-01

    Full Text Available Azimuthal distributions of radial velocities of charged hadrons produced in nucleus-nucleus (AB collisions are compared with the corresponding azimuthal distribution of charged hadron multiplicity in the framework of a multiphase transport (AMPT model at two different collision energies. The mean radial velocity seems to be a good probe for studying radial expansion. While the anisotropic parts of the distributions indicate a kind of collective nature in the radial expansion of the intermediate “fireball,” their isotropic parts characterize a thermal motion. The present investigation is carried out keeping the upcoming Compressed Baryonic Matter (CBM experiment to be held at the Facility for Antiproton and Ion Research (FAIR in mind. As far as high-energy heavy-ion interactions are concerned, CBM will supplement the Relativistic Heavy-Ion Collider (RHIC and Large Hadron Collider (LHC experiments. In this context our simulation results at high baryochemical potential would be interesting, when scrutinized from the perspective of an almost baryon-free environment achieved at RHIC and LHC.

  17. Radial retinotomy in the macula.

    Science.gov (United States)

    Bovino, J A; Marcus, D F

    1984-01-01

    Radial retinotomy is an operative procedure usually performed in the peripheral or equatorial retina. To facilitate retinal attachment, the authors used intraocular scissors to perform radial retinotomy in the macula of two patients during vitrectomy surgery. In the first patient, a retinal detachment complicated by periretinal proliferation and macula hole formation was successfully reoperated with the aid of three radial cuts in the retina at the edges of the macular hole. In the second patient, an intraoperative retinal tear in the macula during diabetic vitrectomy was also successfully repaired with the aid of radial retinotomy. In both patients, retinotomy in the macula was required because epiretinal membranes, which could not be easily delaminated, were hindering retinal reattachment.

  18. Detonation in supersonic radial outflow

    KAUST Repository

    Kasimov, Aslan R.; Korneev, Svyatoslav

    2014-01-01

    We report on the structure and dynamics of gaseous detonation stabilized in a supersonic flow emanating radially from a central source. The steady-state solutions are computed and their range of existence is investigated. Two-dimensional simulations

  19. Dedicated radial ventriculography pigtail catheter

    Energy Technology Data Exchange (ETDEWEB)

    Vidovich, Mladen I., E-mail: miv@uic.edu

    2013-05-15

    A new dedicated cardiac ventriculography catheter was specifically designed for radial and upper arm arterial access approach. Two catheter configurations have been developed to facilitate retrograde crossing of the aortic valve and to conform to various subclavian, ascending aortic and left ventricular anatomies. The “short” dedicated radial ventriculography catheter is suited for horizontal ascending aortas, obese body habitus, short stature and small ventricular cavities. The “long” dedicated radial ventriculography catheter is suited for vertical ascending aortas, thin body habitus, tall stature and larger ventricular cavities. This new design allows for improved performance, faster and simpler insertion in the left ventricle which can reduce procedure time, radiation exposure and propensity for radial artery spasm due to excessive catheter manipulation. Two different catheter configurations allow for optimal catheter selection in a broad range of patient anatomies. The catheter is exceptionally stable during contrast power injection and provides equivalent cavity opacification to traditional femoral ventriculography catheter designs.

  20. Variable surface composition and radial interface formation in self-assembled free, mixed Ar/Xe clusters

    International Nuclear Information System (INIS)

    Tchaplyguine, M.; Maartensson, N.; Lundwall, M.; Oehrwall, G.; Feifel, R.; Svensson, S.; Bjoerneholm, O.; Gisselbrecht, M.; Sorensen, S.

    2004-01-01

    Using photoelectron spectroscopy, we demonstrate how the self-assembling process of cluster formation in an adiabatic expansion leads to radial segregation and layering as well as to variable surface composition for binary Ar/Xe clusters. The radial structuring can be qualitatively understood from the different interatomic bonding strengths of the two components

  1. Organisms modeling: The question of radial basis function networks

    Directory of Open Access Journals (Sweden)

    Muzy Alexandre

    2014-01-01

    Full Text Available There exists usually a gap between bio-inspired computational techniques and what biologists can do with these techniques in their current researches. Although biology is the root of system-theory and artifical neural networks, computer scientists are tempted to build their own systems independently of biological issues. This publication is a first-step re-evalution of an usual machine learning technique (radial basis funtion(RBF networks in the context of systems and biological reactive organisms.

  2. Cathode plasma expansion in diode with explosive emission

    International Nuclear Information System (INIS)

    Zuo Yinghong; Fan Ruyu; Wang Jianguo; Zhu Jinhui

    2012-01-01

    The evolution characteristics of the cathode plasma in a planar diode with explosive emission were analyzed. Be- sides the axial expansion which can reduce the effective anode-cathode gap, the radial expansion of the cathode plasma which can affect the effective emitting area was also taken into account. According to the Child-Langmuir law and the experimental data of current and voltage with a electron vacuum diode under four-pulse mode, the dynamics of the cathode plasma was investigated, on the assumption that the radial speeds of the cathode plasma was approximately equal to the axial speed. The results show that the radial and axial expansion speeds of the cathode plasma are 0.9-2.8 cm/μs. (authors)

  3. Comparison of Deterministic and Probabilistic Radial Distribution Systems Load Flow

    Science.gov (United States)

    Gupta, Atma Ram; Kumar, Ashwani

    2017-12-01

    Distribution system network today is facing the challenge of meeting increased load demands from the industrial, commercial and residential sectors. The pattern of load is highly dependent on consumer behavior and temporal factors such as season of the year, day of the week or time of the day. For deterministic radial distribution load flow studies load is taken as constant. But, load varies continually with a high degree of uncertainty. So, there is a need to model probable realistic load. Monte-Carlo Simulation is used to model the probable realistic load by generating random values of active and reactive power load from the mean and standard deviation of the load and for solving a Deterministic Radial Load Flow with these values. The probabilistic solution is reconstructed from deterministic data obtained for each simulation. The main contribution of the work is: Finding impact of probable realistic ZIP load modeling on balanced radial distribution load flow. Finding impact of probable realistic ZIP load modeling on unbalanced radial distribution load flow. Compare the voltage profile and losses with probable realistic ZIP load modeling for balanced and unbalanced radial distribution load flow.

  4. Radial lean direct injection burner

    Science.gov (United States)

    Khan, Abdul Rafey; Kraemer, Gilbert Otto; Stevenson, Christian Xavier

    2012-09-04

    A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages. The method includes introducing an air flow into the air passages at the inlet end; introducing a fuel into fuel passages; swirling the air flow at the outlet end; and radially injecting the fuel into the swirling air flow.

  5. Self-consistent radial sheath

    International Nuclear Information System (INIS)

    Hazeltine, R.D.

    1988-12-01

    The boundary layer arising in the radial vicinity of a tokamak limiter is examined, with special reference to the TEXT tokamak. It is shown that sheath structure depends upon the self-consistent effects of ion guiding-center orbit modification, as well as the radial variation of E /times/ B-induced toroidal rotation. Reasonable agreement with experiment is obtained from an idealized model which, however simplified, preserves such self-consistent effects. It is argued that the radial sheath, which occurs whenever confining magnetic field-lines lie in the plasma boundary surface, is an object of some intrinsic interest. It differs from the more familiar axial sheath because magnetized charges respond very differently to parallel and perpendicular electric fields. 11 refs., 1 fig

  6. Detonation in supersonic radial outflow

    KAUST Repository

    Kasimov, Aslan R.

    2014-11-07

    We report on the structure and dynamics of gaseous detonation stabilized in a supersonic flow emanating radially from a central source. The steady-state solutions are computed and their range of existence is investigated. Two-dimensional simulations are carried out in order to explore the stability of the steady-state solutions. It is found that both collapsing and expanding two-dimensional cellular detonations exist. The latter can be stabilized by putting several rigid obstacles in the flow downstream of the steady-state sonic locus. The problem of initiation of standing detonation stabilized in the radial flow is also investigated numerically. © 2014 Cambridge University Press.

  7. Vortex Whistle in Radial Intake

    National Research Council Canada - National Science Library

    Tse, Man-Chun

    2004-01-01

    In a radial-to-axial intake with inlet guide vanes (IGV) at the entry, a strong flow circulation Gamma can be generated from the tangential flow components created by the IGVs when their setting exceed about halfclosing (approx. 45 deg...

  8. Radial head dislocation during proximal radial shaft osteotomy.

    Science.gov (United States)

    Hazel, Antony; Bindra, Randy R

    2014-03-01

    The following case report describes a 48-year-old female patient with a longstanding both-bone forearm malunion, who underwent osteotomies of both the radius and ulna to improve symptoms of pain and lack of rotation at the wrist. The osteotomies were templated preoperatively. During surgery, after performing the planned radial shaft osteotomy, the authors recognized that the radial head was subluxated. The osteotomy was then revised from an opening wedge to a closing wedge with improvement of alignment and rotation. The case report discusses the details of the operation, as well as ways in which to avoid similar shortcomings in the future. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  9. RADIAL STABILITY IN STRATIFIED STARS

    International Nuclear Information System (INIS)

    Pereira, Jonas P.; Rueda, Jorge A.

    2015-01-01

    We formulate within a generalized distributional approach the treatment of the stability against radial perturbations for both neutral and charged stratified stars in Newtonian and Einstein's gravity. We obtain from this approach the boundary conditions connecting any two phases within a star and underline its relevance for realistic models of compact stars with phase transitions, owing to the modification of the star's set of eigenmodes with respect to the continuous case

  10. Reactive Arthritis

    Directory of Open Access Journals (Sweden)

    Eren Erken

    2013-06-01

    Full Text Available Reactive arthritis is an acute, sterile, non-suppurative and inflammatory arthropaty which has occured as a result of an infectious processes, mostly after gastrointestinal and genitourinary tract infections. Reiter syndrome is a frequent type of reactive arthritis. Both reactive arthritis and Reiter syndrome belong to the group of seronegative spondyloarthropathies, associated with HLA-B27 positivity and characterized by ongoing inflammation after an infectious episode. The classical triad of Reiter syndrome is defined as arthritis, conjuctivitis and urethritis and is seen only in one third of patients with Reiter syndrome. Recently, seronegative asymmetric arthritis and typical extraarticular involvement are thought to be adequate for the diagnosis. However, there is no established criteria for the diagnosis of reactive arthritis and the number of randomized and controlled studies about the therapy is not enough. [Archives Medical Review Journal 2013; 22(3.000: 283-299

  11. Velocidades radiales en Collinder 121

    Science.gov (United States)

    Arnal, M.; Morrell, N.

    Se han llevado a cabo observaciones espectroscópicas de unas treinta estrellas que son posibles miembros del cúmulo abierto Collinder 121. Las mismas fueron realizadas con el telescopio de 2.15m del Complejo Astronómico El Leoncito (CASLEO). El análisis de las velocidades radiales derivadas del material obtenido, confirma la realidad de Collinder 121, al menos desde el punto de vista cinemático. La velocidad radial baricentral (LSR) del cúmulo es de +17 ± 3 km.s-1. Esta velocidad coincide, dentro de los errores, con la velocidad radial (LSR) de la nebulosa anillo S308, la cual es de ~20 ± 10 km.s-1. Como S308 se encuentra físicamente asociada a la estrella Wolf-Rayet HD~50896, es muy probable que esta última sea un miembro de Collinder 121. Desde un punto de vista cinemático, la supergigante roja HD~50877 (K3Iab) también pertenecería a Collinder 121. Basándonos en la pertenencia de HD~50896 a Collinder 121, y en la interacción encontrada entre el viento de esta estrella y el medio interestelar circundante a la misma, se estima para este cúmulo una distancia del orden de 1 kpc.

  12. Asymptotic expansions of Mathieu functions in wave mechanics

    International Nuclear Information System (INIS)

    Hunter, G.; Kuriyan, M.

    1976-01-01

    Solutions of the radial Schroedinger equation containing a polarization potential r -4 are expanded in a form appropriate for large values of r. These expansions of the Mathieu functions are used in association with the numerical solution of the Schroedinger equation to impose the asymptotic boundary condition in the case of bound states, and to extract phase shifts in the case of scattering states

  13. Negative thermal expansion materials

    International Nuclear Information System (INIS)

    Evans, J.S.O.

    1997-01-01

    The recent discovery of negative thermal expansion over an unprecedented temperature range in ZrW 2 O 8 (which contracts continuously on warming from below 2 K to above 1000 K) has stimulated considerable interest in this unusual phenomenon. Negative and low thermal expansion materials have a number of important potential uses in ceramic, optical and electronic applications. We have now found negative thermal expansion in a large new family of materials with the general formula A 2 (MO 4 ) 3 . Chemical substitution dramatically influences the thermal expansion properties of these materials allowing the production of ceramics with negative, positive or zero coefficients of thermal expansion, with the potential to control other important materials properties such as refractive index and dielectric constant. The mechanism of negative thermal expansion and the phase transitions exhibited by this important new class of low-expansion materials will be discussed. (orig.)

  14. On equivalence of high temperature series expansion and coupling parameter series expansion in thermodynamic perturbation theory of fluids

    International Nuclear Information System (INIS)

    Sai Venkata Ramana, A.

    2014-01-01

    The coupling parameter series expansion and the high temperature series expansion in the thermodynamic perturbation theory of fluids are shown to be equivalent if the interaction potential is pairwise additive. As a consequence, for the class of fluids with the potential having a hardcore repulsion, if the hard-sphere fluid is chosen as reference system, the terms of coupling parameter series expansion for radial distribution function, direct correlation function, and Helmholtz free energy follow a scaling law with temperature. The scaling law is confirmed by application to square-well fluids

  15. Geometry of solar corona expansion and solar wind parameters

    International Nuclear Information System (INIS)

    Krajnev, M.B.

    1980-01-01

    The character of the parameter chanqe of solar wind plasma in the region of the Earth orbit is studied. The main regularities in the parametep behaviour of solar wind (plasma velocity and density) are qualitatively explained in the framework of a model according to which solar corona expansion stronqly differs from radial expansion, that is: the solar wind current lines are focused towards helioequator during the period of low solar activity with gradual transfer to radial expansion during the years of high solar activity. It is shown that the geometry of the solar wind current tubes and its change with the solar activity cycle can not serve an explanation of the observed change of the solar wind parameters

  16. Exceptional circles of radial potentials

    International Nuclear Information System (INIS)

    Music, M; Perry, P; Siltanen, S

    2013-01-01

    A nonlinear scattering transform is studied for the two-dimensional Schrödinger equation at zero energy with a radial potential. Explicit examples are presented, both theoretically and computationally, of potentials with nontrivial singularities in the scattering transform. The singularities arise from non-uniqueness of the complex geometric optics solutions that define the scattering transform. The values of the complex spectral parameter at which the singularities appear are called exceptional points. The singularity formation is closely related to the fact that potentials of conductivity type are ‘critical’ in the sense of Murata. (paper)

  17. Experimental research on time-resolved evolution of cathode plasma expansion velocity in a long pulsed magnetically insulated coaxial diode

    Science.gov (United States)

    Zhu, Danni; Zhang, Jun; Zhong, Huihuang; Ge, Xingjun; Gao, Jingming

    2018-02-01

    Unlike planar diodes, separate research of the axial and radial plasma expansion velocities is difficult for magnetically insulated coaxial diodes. Time-resolved electrical diagnostic which is based on the voltage-ampere characteristics has been employed to study the temporal evolution of the axial and radial cathode plasma expansion velocities in a long pulsed magnetically insulated coaxial diode. Different from a planar diode with a "U" shaped profile of temporal velocity evolution, the temporal evolution trend of the axial expansion velocity is proved to be a "V" shaped profile. Apart from the suppression on the radial expansion velocity, the strong magnetic field is also conducive to slowing down the axial expansion velocity. Compared with the ordinary graphite cathode, the carbon velvet and graphite composite cathode showed superior characteristics as judged by the low plasma expansion velocity and long-term electrical stability as a promising result for applications where long-pulsed and reliable operation at high power is required.

  18. Radial optimization of a BWR fuel cell using genetic algorithms

    International Nuclear Information System (INIS)

    Martin del Campo M, C.; Carmona H, R.; Oropeza C, I.P.

    2006-01-01

    the bars of water, were applied. However the placement of the bars with gadolinia inside the cell was free. The obtained results were excellent, its were found forty designs that fulfill the wanted reactivity and the peak factor of radial power. The best of them has an neutron acting superior to the design of the reference cell using an average smaller enrichment. (Author)

  19. ION-SCALE TURBULENCE IN THE INNER HELIOSPHERE: RADIAL DEPENDENCE

    Energy Technology Data Exchange (ETDEWEB)

    Comisel, H.; Motschmann, U.; Büchner, J.; Narita, Y.; Nariyuki, Y. [University of Toyama, Faculty of Human Development, 3190, Gofuku, Toyama, 930-8555 (Japan)

    2015-10-20

    The evolution of the ion-scale plasma turbulence in the inner heliosphere is studied by associating the plasma parameters for hybrid-code turbulence simulations to the radial distance from the Sun via a Solar wind model based mapping procedure. Using a mapping based on a one-dimensional solar wind expansion model, the resulting ion-kinetic scale turbulence is related to the solar wind distance from the Sun. For this purpose the mapping is carried out for various values of ion beta that correspond to the heliocentric distance. It is shown that the relevant normal modes such as ion cyclotron and ion Bernstein modes will occur first at radial distances of about 0.2–0.3 AU, i.e., near the Mercury orbit. This finding can be used as a reference, a prediction to guide the in situ measurements to be performed by the upcoming Solar Orbiter and Solar Probe Plus missions. Furthermore, a radial dependence of the wave-vector anisotropy was obtained. For astrophysical objects this means that the spatial scales of filamentary structures in interstellar media or astrophysical jets can be predicted for photometric observations.

  20. Expansion joints for LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Dzenus, M.; Hundhausen, W.; Jansing, W.

    1979-10-15

    This discourse recounts efforts put into the SNR-2 project; specifically the development of compensation devices. The various prototypes of these compensation devices are described and the state of development reviewed. The expansion joints were developed on the basis of specific design criteria whereby differentiation is made between expansion joints of small and large nominal diameter. Expansion joints for installation in the sodium-filled primary piping are equipped with safety bellows in addition to the actual working bellows.

  1. Radial smoothing and closed orbit

    International Nuclear Information System (INIS)

    Burnod, L.; Cornacchia, M.; Wilson, E.

    1983-11-01

    A complete simulation leading to a description of one of the error curves must involve four phases: (1) random drawing of the six set-up points within a normal population having a standard deviation of 1.3 mm; (b) random drawing of the six vertices of the curve in the sextant mode within a normal population having a standard deviation of 1.2 mm. These vertices are to be set with respect to the axis of the error lunes, while this axis has as its origins the positions defined by the preceding drawing; (c) mathematical definition of six parabolic curves and their junctions. These latter may be curves with very slight curvatures, or segments of a straight line passing through the set-up point and having lengths no longer than one LSS. Thus one gets a mean curve for the absolute errors; (d) plotting of the actually observed radial positions with respect to the mean curve (results of smoothing)

  2. Waves on radial film flows

    Science.gov (United States)

    Cholemari, Murali R.; Arakeri, Jaywant H.

    2005-08-01

    We study the stability of surface waves on the radial film flow created by a vertical cylindrical water jet striking a horizontal plate. In such flows, surface waves have been found to be unstable and can cause transition to turbulence. This surface-wave-induced transition is different from the well-known Tollmien-Schlichting wave-induced transition. The present study aims at understanding the instability and the transition process. We do a temporal stability analysis by assuming the flow to be locally two-dimensional but including spatial variations to first order in the basic flow. The waves are found to be dispersive, mostly unstable, and faster than the mean flow. Spatial variation is the major destabilizing factor. Experiments are done to test the results of the linear stability analysis and to document the wave breakup and transition. Comparison between theory and experiments is fairly good and indicates the adequacy of the model.

  3. Radial flow gas dynamic laser

    International Nuclear Information System (INIS)

    Damm, F.C.

    1975-01-01

    The unique gas dynamic laser provides outward radial supersonic flow from a toroidal shaped stacked array of a plurality of nozzles, through a diffuser having ring shaped and/or linear shaped vanes, and through a cavity which is cylindrical and concentric with the stacked array, with the resultant laser beam passing through the housing parallel to the central axis of the diffuser which is coincident with the axis of the gas dynamic laser. Therefore, greater beam extraction flexibility is attainable, because of fewer flow shock disturbances, as compared to the conventional unidirectional flow gas dynamic laser in which unidirectional supersonic flow sweeps through a rectangular cavity and is exhausted through a two-dimensional diffuser. (auth)

  4. Ulnar nerve entrapment complicating radial head excision

    Directory of Open Access Journals (Sweden)

    Kevin Parfait Bienvenu Bouhelo-Pam

    Full Text Available Introduction: Several mechanisms are involved in ischemia or mechanical compression of ulnar nerve at the elbow. Presentation of case: We hereby present the case of a road accident victim, who received a radial head excision for an isolated fracture of the radial head and complicated by onset of cubital tunnel syndrome. This outcome could be the consequence of an iatrogenic valgus of the elbow due to excision of the radial head. Hitherto the surgical treatment of choice it is gradually been abandoned due to development of radial head implant arthroplasty. However, this management option is still being performed in some rural centers with low resources. Discussion: The radial head plays an important role in the stability of the elbow and his iatrogenic deformity can be complicated by cubital tunnel syndrome. Conclusion: An ulnar nerve release was performed with favorable outcome. Keywords: Cubital tunnel syndrome, Peripheral nerve palsy, Radial head excision, Elbow valgus

  5. Stirling Engine With Radial Flow Heat Exchangers

    Science.gov (United States)

    Vitale, N.; Yarr, George

    1993-01-01

    Conflict between thermodynamical and structural requirements resolved. In Stirling engine of new cylindrical configuration, regenerator and acceptor and rejector heat exchangers channel flow of working gas in radial direction. Isotherms in regenerator ideally concentric cylinders, and gradient of temperature across regenerator radial rather than axial. Acceptor and rejector heat exchangers located radially inward and outward of regenerator, respectively. Enables substantial increase in power of engine without corresponding increase in diameter of pressure vessel.

  6. Reactive Systems

    DEFF Research Database (Denmark)

    Aceto, Luca; Ingolfsdottir, Anna; Larsen, Kim Guldstrand

    A reactive system comprises networks of computing components, achieving their goals through interaction among themselves and their environment. Thus even relatively small systems may exhibit unexpectedly complex behaviours. As moreover reactive systems are often used in safety critical systems......, the need for mathematically based formal methodology is increasingly important. There are many books that look at particular methodologies for such systems. This book offers a more balanced introduction for graduate students and describes the various approaches, their strengths and weaknesses, and when...... they are best used. Milner's CCS and its operational semantics are introduced, together with the notions of behavioural equivalences based on bisimulation techniques and with recursive extensions of Hennessy-Milner logic. In the second part of the book, the presented theories are extended to take timing issues...

  7. Convergence of mayer expansions

    International Nuclear Information System (INIS)

    Brydges, D.C.

    1986-01-01

    The tree graph bound of Battle and Federbush is extended and used to provide a simple criterion for the convergence of (iterated) Mayer expansions. As an application estimates on the radius of convergence of the Mayer expansion for the two-dimensional Yukawa gas (nonstable interaction) are obtained

  8. On improved confinement in mirror plasmas by a radial electric field

    Science.gov (United States)

    Ågren, O.; Moiseenko, V. E.

    2017-11-01

    A weak radial electric field can suppress radial excursions of a guiding center from its mean magnetic surface. The physical origin of this effect is the smearing action by a poloidal E × B rotation, which tend to cancel out the inward and outward radial drifts. A use of this phenomenon may provide larger margins for magnetic field shaping with radial confinement of particles maintained in the collision free idealization. Mirror fields, stabilized by a quadrupolar field component, are of particular interest for their MHD stability and the possibility to control the quasi neutral radial electric field by biased potential plates outside the confinement region. Flux surface footprints on the end tank wall have to be traced to avoid short-circuiting between biased plates. Assuming a robust biasing procedure, moderate voltage demands for the biased plates seems adequate to cure even the radial excursions of Yushmanov ions which could be locally trapped near the mirrors. Analytical expressions are obtained for a magnetic quadrupolar mirror configuration which possesses minimal radial magnetic drifts in the central confinement region. By adding a weak controlled radial quasi-neutral electric field, the majority of gyro centers are predicted to be forced to move even closer to their respective mean magnetic surface. The gyro center radial coordinate is in such a case an accurate approximation for a constant of motion. By using this constant of motion, the analysis is in a Vlasov description extended to finite β. A correspondence between that Vlasov system and a fluid description with a scalar pressure and an electric potential is verified. The minimum B criterion is considered and implications for flute mode stability in the considered magnetic field is analyzed. By carrying out a long-thin expansion to a higher order, the validity of the calculations are extended to shorter and more compact device designs.

  9. Radial head button holing: a cause of irreducible anterior radial head dislocation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Su-Mi; Chai, Jee Won; You, Ja Yeon; Park, Jina [Seoul National University Seoul Metropolitan Government Boramae Medical Center, Department of Radiology, Seoul (Korea, Republic of); Bae, Kee Jeong [Seoul National University Seoul Metropolitan Government Boramae Medical Center, Department of Orthopedic Surgery, Seoul (Korea, Republic of)

    2016-10-15

    ''Buttonholing'' of the radial head through the anterior joint capsule is a known cause of irreducible anterior radial head dislocation associated with Monteggia injuries in pediatric patients. To the best of our knowledge, no report has described an injury consisting of buttonholing of the radial head through the annular ligament and a simultaneous radial head fracture in an adolescent. In the present case, the radiographic findings were a radial head fracture with anterior dislocation and lack of the anterior fat pad sign. Magnetic resonance imaging (MRI) clearly demonstrated anterior dislocation of the fractured radial head through the torn annular ligament. The anterior joint capsule and proximal portion of the annular ligament were interposed between the radial head and capitellum, preventing closed reduction of the radial head. Familiarity with this condition and imaging findings will aid clinicians to make a proper diagnosis and fast decision to perform an open reduction. (orig.)

  10. Photoelectric Radial Velocities, Paper XIX Additional Spectroscopic ...

    Indian Academy of Sciences (India)

    ian velocity curve that does justice to the measurements, but it cannot be expected to have much predictive power. Key words. Stars: late-type—stars: radial velocities—spectroscopic binaries—orbits. 0. Preamble. The 'Redman K stars' are a lot of seventh-magnitude K stars whose radial velocities were first observed by ...

  11. Radial velocities of RR Lyrae stars

    International Nuclear Information System (INIS)

    Hawley, S.L.; Barnes, T.G. III

    1985-01-01

    283 spectra of 57 RR Lyrae stars have been obtained using the 2.1-m telescope at McDonald Observatory. Radial velocities were determined using a software cross-correlation technique. New mean radial velocities were determined for 46 of the stars. 11 references

  12. Concepts of radial and angular kinetic energies

    DEFF Research Database (Denmark)

    Dahl, Jens Peder; Schleich, W.P.

    2002-01-01

    We consider a general central-field system in D dimensions and show that the division of the kinetic energy into radial and angular parts proceeds differently in the wave-function picture and the Weyl-Wigner phase-space picture, Thus, the radial and angular kinetic energies are different quantities...

  13. Investigation of the organic Rankine cycle (ORC) system and the radial-inflow turbine design

    International Nuclear Information System (INIS)

    Li, Yan; Ren, Xiao-dong

    2016-01-01

    Highlights: • The thermodynamic analysis of an ORC system is introduced. • A radial turbine design method has been proposed based on the real gas model. • A radial turbine with R123 is designed and numerically analyzed. - Abstract: Energy and environment issue set utilizing low-grade heat noticed. Organic Rankine Cycle (ORC) has been demonstrated to be a promising technology to recover waste heat. As a critical component of ORC system, the turbine selection has an enormous influence on the system performance. This paper carries out a study on the thermodynamic analysis of ORC system and the aerodynamic design of an organic radial turbine. The system performance is evaluated with various working fluids. The aerodynamic design of the organic radial-inflow turbine is focused due to the high molecule weight and the low sound speed of the organic working fluid. An aerodynamic and profile design system is developed. A radial-inflow turbine with R123 as the working fluid is designed and the numerical analysis is conducted. The simulation results indicate that the shock wave caused by the high expansion ratio in the nozzle is well controlled. Compared with the one-dimensional design results, the performance of the radial-inflow turbine in this paper reaches the design requirements.

  14. Spherical harmonic expansion of short-range screened Coulomb interactions

    Energy Technology Data Exchange (ETDEWEB)

    Angyan, Janos G [Laboratoire de Cristallographie et de Modelisation des Materiaux Mineraux et Biologiques, UMR 7036, CNRS-Universite Henri Poincare, BP 239, F-54506 Vandoeuvre-les-Nancy (France); Gerber, Iann [Laboratoire de Cristallographie et de Modelisation des Materiaux Mineraux et Biologiques, UMR 7036, CNRS-Universite Henri Poincare, BP 239, F-54506 Vandoeuvre-les-Nancy (France); Marsman, Martijn [Institut fuer Materialphysik and Center for Computational Materials Science, Universitaet Wien, Sensengasse 8, A-1090, Vienna (Austria)

    2006-07-07

    Spherical harmonic expansions of the screened Coulomb interaction kernel involving the complementary error function are required in various problems in atomic, molecular and solid state physics, like for the evaluation of Ewald-type lattice sums or for range-separated hybrid density functionals. A general analytical expression is derived for the kernel, which is non-separable in the radial variables. With the help of series expansions a separable approximate form is proposed, which is in close analogy with the conventional multipole expansion of the Coulomb kernel in spherical harmonics. The convergence behaviour of these expansions is studied and illustrated by the electrostatic potential of an elementary charge distribution formed by products of Slater-type atomic orbitals.

  15. Controlled Thermal Expansion Alloys

    Data.gov (United States)

    National Aeronautics and Space Administration — There has always been a need for controlled thermal expansion alloys suitable for mounting optics and detectors in spacecraft applications.  These alloys help...

  16. Fuel Thermal Expansion (FTHEXP)

    International Nuclear Information System (INIS)

    Reymann, G.A.

    1978-07-01

    A model is presented which deals with dimensional changes in LWR fuel pellets caused by changes in temperature. It is capable of dealing with any combination of UO 2 and PuO 2 in solid, liquid or mixed phase states, and includes expansion due to the solid-liquid phase change. The function FTHEXP models fuel thermal expansion as a function of temperature, fraction of PuO 2 , and the fraction of fuel which is molten

  17. Improved wave functions for large-N expansions

    International Nuclear Information System (INIS)

    Imbo, T.; Sukhatme, U.

    1985-01-01

    Existing large-N expansions of radial wave functions phi/sub n/,l(r) are only accurate near the minimum of the effective potential. Within the framework of the shifted 1/N expansion, we use known analytic results to motivate a simple modification so that the improved wave functions are accurate over a wide range of r and any choice of quantum numbers n and l. It is shown that these wave functions yield simple and accurate analytic expressions for certain quantities of interest in quarkonium physics

  18. Inadvertent pump start with gas expansion modules

    International Nuclear Information System (INIS)

    Campbell, L.R.; Harris, R.A.; Heard, F.J.; Dautel, W.A.

    1992-01-01

    Previous testing demonstrated the effectiveness of gas expansion modules (GEMs) in mitigating the consequences of a loss-of-flow-without-scram transient in Fast Flux Test Facility (FFTF)-sized sodium cooled cores. As a result, GEMs have been included in the advance liquid-metal reactor (PRISM) design project sponsored by the US Department of Energy. The PRISM design is under review at the US Nuclear Regulatory Commission for licensability. In the unlikely event that the reactor does not scram during a loss of low, the GEMs quickly insert sufficient negative reactivity to limit fuel and cladding temperatures to acceptable values. This is the positive benefit of the GEMs; however, the reverse situation must be considered. A primary pump could be inadvertently started from near-critical conditions resulting in a positive reactivity insertion and a power transient. One mitigating aspect of this event is that as the reactivity associated with the GEMs is inserted, the increasing flow increases core cooling. A test was conducted in the FFTF to demonstrate that the GEM and feedback reactivity are well predicted following pump start, and the reactivity transient is benign

  19. A perturbation effect in the reflector of a reactor. The case of a radial channel; Effet d'une perturbation dans le reflecteur d'une pile. Cas d'un canal radial

    Energy Technology Data Exchange (ETDEWEB)

    Lerouge, B; Raievski, V [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    The absorption and the transport effect in a channel within the reflector of a reactor has been already studied with the first group theory, this study will discuss its resolution with the second group theory which describes the neutron distribution within a reactor by the value of two functions representing respectively the flux of fast neutrons and thermal neutrons, S{sub f} and S{sub s}. The study of the reactivity variation caused by a disturbance in the critical conditions and its application to the effect of a radial channel located within the reflector of a reactor leads to the evaluation of the reactivity drop caused by the presence of radial channels in the fully charged EL3 reactor. Numerical results are given for the contribution of the fast neutron and thermal neutron flux to the reactivity drop as well as the expression of the reactivity drop caused by the neutrons transport effect. (M.P.)

  20. Resonant state expansions

    International Nuclear Information System (INIS)

    Lind, P.

    1993-02-01

    The completeness properties of the discrete set of bound state, virtual states and resonances characterizing the system of a single nonrelativistic particle moving in a central cutoff potential is investigated. From a completeness relation in terms of these discrete states and complex scattering states one can derive several Resonant State Expansions (RSE). It is interesting to obtain purely discrete expansion which, if valid, would significantly simplify the treatment of the continuum. Such expansions can be derived using Mittag-Leffler (ML) theory for a cutoff potential and it would be nice to see if one can obtain the same expansions starting from an eigenfunction theory that is not restricted to a finite sphere. The RSE of Greens functions is especially important, e.g. in the continuum RPA (CRPA) method of treating giant resonances in nuclear physics. The convergence of RSE is studied in simple cases using square well wavefunctions in order to achieve high numerical accuracy. Several expansions can be derived from each other by using the theory of analytic functions and one can the see how to obtain a natural discretization of the continuum. Since the resonance wavefunctions are oscillating with an exponentially increasing amplitude, and therefore have to be interpreted through some regularization procedure, every statement made about quantities involving such states is checked by numerical calculations.Realistic nuclear wavefunctions, generated by a Wood-Saxon potential, are used to test also the usefulness of RSE in a realistic nuclear calculation. There are some fundamental differences between different symmetries of the integral contour that defines the continuum in RSE. One kind of symmetry is necessary to have an expansion of the unity operator that is idempotent. Another symmetry must be used if we want purely discrete expansions. These are found to be of the same form as given by ML. (29 refs.)

  1. Radial electric fields for improved tokamak performance

    International Nuclear Information System (INIS)

    Downum, W.B.

    1981-01-01

    The influence of externally-imposed radial electric fields on the fusion energy output, energy multiplication, and alpha-particle ash build-up in a TFTR-sized, fusing tokamak plasma is explored. In an idealized tokamak plasma, an externally-imposed radial electric field leads to plasma rotation, but no charge current flows across the magnetic fields. However, a realistically-low neutral density profile generates a non-zero cross-field conductivity and the species dependence of this conductivity allows the electric field to selectively alter radial particle transport

  2. Radial MR images of the knee

    International Nuclear Information System (INIS)

    Hewes, R.C.; Miller, T.R.

    1988-01-01

    To profile optimally each portion of the meniscus, the authors use the multiangle, multisection feature of a General Electric SIGNA 1.5-T imager to produce radial images centered on each meniscus. A total of 12-15 sections are imaged at 10 0 -15 0 intervals of each meniscus, yielding perpendicular images of the entire meniscus, comparable with the arthrographic tangential views. The authors review their technique and demonstrate correlation cases between the radial gradient recalled acquisition in a steady state sequences, sagittal and coronal MR images, and arthrograms. Radial images should be a routine part of knee MR imaging

  3. Radial pattern of nuclear decay processes

    International Nuclear Information System (INIS)

    Iskra, W.; Mueller, M.; Rotter, I.; Technische Univ. Dresden

    1994-05-01

    At high level density of nuclear states, a separation of different time scales is observed (trapping effect). We calculate the radial profile of partial widths in the framework of the continuum shell model for some 1 - resonances with 2p-2h nuclear structure in 16 O as a function of the coupling strength to the continuum. A correlation between the lifetime of a nuclear state and the radial profile of the corresponding decay process is observed. We conclude from our numerical results that the trapping effect creates structures in space and time characterized by a small radial extension and a short lifetime. (orig.)

  4. Expansion joints for LMFBR

    International Nuclear Information System (INIS)

    Dzenus, M.; Hundhausen, W.; Jansing, W.

    1980-01-01

    This discourse recounts efforts put into the SNR-2 project; specifically the development of compensation devices. The various prototypes of these compensation devices are described and the state of the development reviewed. Large Na (sodium)-heat transfer systems require a lot of valuable space if the component lay-out does not include compensation devices. So, in order to condense the spatial requirement as much as possible, expansion joints must be integrated into the pipe system. There are two basic types to suit the purpose: axial expansion joints and angular expansion joints. The expansion joints were developed on the basis of specific design criteria whereby differentiation is made between expansion joints of small and large nominal diameter. Expansion joints for installation in the sodium-filled primary piping are equipped with safety bellows in addition to the actual working bellows. Expansion joints must be designed and mounted in a manner to completely withstand seismic forces. The design must exclude any damage to the bellows during intermittent operations, that is, when sodium is drained the bellows' folds must be completely empty; otherwise residual solidified sodium could destroy the bellows when restarting. The expansion joints must be engineered on the basis of the following design data for the secondary system of the SNR project: working pressure: 16 bar; failure mode pressure: 5 events; failure mode: 5 sec., 28.5 bar, 520 deg. C; working temperature: 520 deg. C; temperature transients: 30 deg. C/sec.; service life: 200,000 h; number of load cycles: 10 4 ; material: 1.4948 or 1.4919; layer thickness of folds: 0.5 mm; angular deflection (DN 800): +3 deg. C or; axial expansion absorption (DN 600): ±80 mm; calculation: ASME class. The bellows' development work is not handled within this scope. The bellows are supplied by leading manufacturers, and warrant highest quality. Multiple bellows were selected on the basis of maximum elasticity - a property

  5. Axial SPN and radial MOC coupled whole core transport calculation

    International Nuclear Information System (INIS)

    Cho, Jin-Young; Kim, Kang-Seog; Lee, Chung-Chan; Zee, Sung-Quun; Joo, Han-Gyu

    2007-01-01

    The Simplified P N (SP N ) method is applied to the axial solution of the two-dimensional (2-D) method of characteristics (MOC) solution based whole core transport calculation. A sub-plane scheme and the nodal expansion method (NEM) are employed for the solution of the one-dimensional (1-D) SP N equations involving a radial transverse leakage. The SP N solver replaces the axial diffusion solver of the DeCART direct whole core transport code to provide more accurate, transport theory based axial solutions. In the sub-plane scheme, the radial equivalent homogenization parameters generated by the local MOC for a thick plane are assigned to the multiple finer planes in the subsequent global three-dimensional (3-D) coarse mesh finite difference (CMFD) calculation in which the NEM is employed for the axial solution. The sub-plane scheme induces a much less nodal error while having little impact on the axial leakage representation of the radial MOC calculation. The performance of the sub-plane scheme and SP N nodal transport solver is examined by solving a set of demonstrative problems and the C5G7MOX 3-D extension benchmark problems. It is shown in the demonstrative problems that the nodal error reaching upto 1,400 pcm in a rodded case is reduced to 10 pcm by introducing 10 sub-planes per MOC plane and the transport error is reduced from about 150 pcm to 10 pcm by using SP 3 . Also it is observed, in the C5G7MOX rodded configuration B problem, that the eigenvalues and pin power errors of 180 pcm and 2.2% of the 10 sub-planes diffusion case are reduced to 40 pcm and 1.4%, respectively, for SP 3 with only about a 15% increase in the computing time. It is shown that the SP 5 case gives very similar results to the SP 3 case. (author)

  6. Accelerating the loop expansion

    International Nuclear Information System (INIS)

    Ingermanson, R.

    1986-01-01

    This thesis introduces a new non-perturbative technique into quantum field theory. To illustrate the method, I analyze the much-studied phi 4 theory in two dimensions. As a prelude, I first show that the Hartree approximation is easy to obtain from the calculation of the one-loop effective potential by a simple modification of the propagator that does not affect the perturbative renormalization procedure. A further modification then susggests itself, which has the same nice property, and which automatically yields a convex effective potential. I then show that both of these modifications extend naturally to higher orders in the derivative expansion of the effective action and to higher orders in the loop-expansion. The net effect is to re-sum the perturbation series for the effective action as a systematic ''accelerated'' non-perturbative expansion. Each term in the accelerated expansion corresponds to an infinite number of terms in the original series. Each term can be computed explicitly, albeit numerically. Many numerical graphs of the various approximations to the first two terms in the derivative expansion are given. I discuss the reliability of the results and the problem of spontaneous symmetry-breaking, as well as some potential applications to more interesting field theories. 40 refs

  7. Virial Expansion Bounds

    Science.gov (United States)

    Tate, Stephen James

    2013-10-01

    In the 1960s, the technique of using cluster expansion bounds in order to achieve bounds on the virial expansion was developed by Lebowitz and Penrose (J. Math. Phys. 5:841, 1964) and Ruelle (Statistical Mechanics: Rigorous Results. Benjamin, Elmsford, 1969). This technique is generalised to more recent cluster expansion bounds by Poghosyan and Ueltschi (J. Math. Phys. 50:053509, 2009), which are related to the work of Procacci (J. Stat. Phys. 129:171, 2007) and the tree-graph identity, detailed by Brydges (Phénomènes Critiques, Systèmes Aléatoires, Théories de Jauge. Les Houches 1984, pp. 129-183, 1986). The bounds achieved by Lebowitz and Penrose can also be sharpened by doing the actual optimisation and achieving expressions in terms of the Lambert W-function. The different bound from the cluster expansion shows some improvements for bounds on the convergence of the virial expansion in the case of positive potentials, which are allowed to have a hard core.

  8. Conformal expansions and renormalons

    Energy Technology Data Exchange (ETDEWEB)

    Rathsman, J.

    2000-02-07

    The coefficients in perturbative expansions in gauge theories are factorially increasing, predominantly due to renormalons. This type of factorial increase is not expected in conformal theories. In QCD conformal relations between observables can be defined in the presence of a perturbative infrared fixed-point. Using the Banks-Zaks expansion the authors study the effect of the large-order behavior of the perturbative series on the conformal coefficients. The authors find that in general these coefficients become factorially increasing. However, when the factorial behavior genuinely originates in a renormalon integral, as implied by a postulated skeleton expansion, it does not affect the conformal coefficients. As a consequence, the conformal coefficients will indeed be free of renormalon divergence, in accordance with previous observations concerning the smallness of these coefficients for specific observables. The authors further show that the correspondence of the BLM method with the skeleton expansion implies a unique scale-setting procedure. The BLM coefficients can be interpreted as the conformal coefficients in the series relating the fixed-point value of the observable with that of the skeleton effective charge. Through the skeleton expansion the relevance of renormalon-free conformal coefficients extends to real-world QCD.

  9. Elastic-plastic analysis of tube expansion in tubesheets

    International Nuclear Information System (INIS)

    Kasraie, B.; O'Donnell, W.J.; Porowski, J.S.; Selz, A.

    1983-01-01

    Conditions for expansion of tubes in tubesheets are often determined by the test. The tightness of the joint and pull out force are used as criteria for evaluation of the results. For closely spaced tubes, it is also necessary to control development of the plastic regions in the ligaments surrounding the tube being expanded. High local strains may occur and excessive distortion may result if the expansion of the tube is continued beyond the admissible limits. Elastic-plastic finite element analyses are performed herein in order to establish conditions for rolling of the tubes in tubesheets of low ligament efficiency. Such penetration patterns are often required in the design of tubular reactors for catalytic processes. The model considered includes individual tube expansion in tubesheets with triangular penetration patterns. The effect of prior expansion of the neighboring tubes is also evaluated. Gap elements are used to model the initial clearance of the tube in the hole. Development of the plastic zones and distortion of the ligaments is monitored during radial expansion of the tube diameter. The residual stresses between the tube and the hole surface and the history of gap closing after removal of the expansion tool are determined. The effect of axial extension of the tube on the tube thinning is determined. Tube thinning is often used as a measure of tube expansion in manufacturing processes. For the analyzed ligament efficiency, reliable joints are obtained for a thinning range within 2% to 3%

  10. Thermal expansion data

    International Nuclear Information System (INIS)

    Taylor, D.

    1984-01-01

    This paper gives regression data for a modified second order polynomial fitted to the expansion data of, and percentage expansions for dioxides with (a) the fluorite and antifluorite structure: AmO 2 , BkO 2 , CeO 2 , CmO 2 , HfO 2 , Li 2 O, NpO 2 , PrO 2 , PuO 2 , ThO 2 , UO 2 , ZrO 2 , and (b) the rutile structure: CrO 2 , GeO 2 , IrO 2 , MnO 2 , NbO 2 , PbO 2 , SiO 2 , SnO 2 , TeO 2 , TiO 2 and VO 2 . Reduced expansion curves for the dioxides showed only partial grouping into iso-electronic series for the fluorite structures and showed that the 'law of corresponding states' did not apply to the rutile structures. (author)

  11. Radial pseudoaneurysm following diagnostic coronary angiography

    Directory of Open Access Journals (Sweden)

    Shankar Laudari

    2015-06-01

    Full Text Available The radial artery access has gained popularity as a method of diagnostic coronary catheterization compared to femoral artery puncture in terms of vascular complications and early ambulation. However, very rare complication like radial artery pseudoaneurysm may occur following cardiac catheterization which may give rise to serious consequences. Here, we report a patient with radial pseudoaneurysm following diagnostic coronary angiography. Adequate and correct methodology of compression of radial artery following puncture for maintaining hemostasis is the key to prevention.DOI: http://dx.doi.org/10.3126/jcmsn.v10i3.12776 Journal of College of Medical Sciences-Nepal, 2014, Vol-10, No-3, 48-50

  12. Uniform gradient expansions

    CERN Document Server

    Giovannini, Massimo

    2015-01-01

    Cosmological singularities are often discussed by means of a gradient expansion that can also describe, during a quasi-de Sitter phase, the progressive suppression of curvature inhomogeneities. While the inflationary event horizon is being formed the two mentioned regimes coexist and a uniform expansion can be conceived and applied to the evolution of spatial gradients across the protoinflationary boundary. It is argued that conventional arguments addressing the preinflationary initial conditions are necessary but generally not sufficient to guarantee a homogeneous onset of the conventional inflationary stage.

  13. Radial transport with perturbed magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Hazeltine, R. D. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)

    2015-05-15

    It is pointed out that the viscosity coefficient describing radial transport of toroidal angular momentum is proportional to the second power of the gyro-radius—like the corresponding coefficients for particle and heat transport—regardless of any geometrical symmetry. The observation is widely appreciated, but worth emphasizing because some literature gives the misleading impression that asymmetry can allow radial moment transport in first-order.

  14. Radial transport with perturbed magnetic field

    International Nuclear Information System (INIS)

    Hazeltine, R. D.

    2015-01-01

    It is pointed out that the viscosity coefficient describing radial transport of toroidal angular momentum is proportional to the second power of the gyro-radius—like the corresponding coefficients for particle and heat transport—regardless of any geometrical symmetry. The observation is widely appreciated, but worth emphasizing because some literature gives the misleading impression that asymmetry can allow radial moment transport in first-order

  15. Low-temperature thermal expansion

    International Nuclear Information System (INIS)

    Collings, E.W.

    1986-01-01

    This chapter discusses the thermal expansion of insulators and metals. Harmonicity and anharmonicity in thermal expansion are examined. The electronic, magnetic, an other contributions to low temperature thermal expansion are analyzed. The thermodynamics of the Debye isotropic continuum, the lattice-dynamical approach, and the thermal expansion of metals are discussed. Relative linear expansion at low temperatures is reviewed and further calculations of the electronic thermal expansion coefficient are given. Thermal expansions are given for Cu, Al and Ti. Phenomenologic thermodynamic relationships are also discussed

  16. The Role of the Process and Design Variables in Improving the Performance of Heat Exchanger Tube Expansion

    Directory of Open Access Journals (Sweden)

    Changwan Han

    2018-05-01

    Full Text Available In the expansion process of a fin-tube heat exchanger, the process variables and shape of the expansion ball affect the deformation of the tube’s inner grooves, the adhesion, and the expansion force. These factors influence the efficiency of heat transfer and the lifetime of the expansion equipment. Therefore, this study analyzed the influential variables of the tube expansion process as well as the expansion ball design through experiments and simulations. A new method was proposed to determine the severity of adhesion in the tube’s inner grooves using the expansion force rate. Expansion experiments with Al tubes show that the expansion force decreases when using a lubricant with high viscosity and when the lubricant remains on the expansion ball for a longer duration. Finite element analysis was also performed to examine the expansion of Cu tubes, which showed that the expansion force was higher when using expansion ball shapes that have higher contact area between the ball and tube surface. The radius of curvature of the expansion ball also influenced the expansion force. However, increasing the ratio of the radial force to the expansion force increased the deformation of the tube’s inner grooves.

  17. Stability of radial and non-radial pulsation modes of massive ZAMS models

    International Nuclear Information System (INIS)

    Odell, A.P.; Pausenwein, A.; Weiss, W.W.; Hajek, A.

    1987-01-01

    The authors have computed non-adiabatic eigenvalues for radial and non-radial pulsation modes of star models between 80 and 120 M solar with composition of chi=0.70 and Z=0.02. The radial fundamental mode is unstable in models with mass greater than 95 M solar , but the first overtone mode is always stable. The non-radial modes are all stable for all models, but the iota=2 f-mode is the closest to being driven. The non-radial modes are progressively more stable with higher iota and with higher n (for both rho- and g-modes). Thus, their results indicate that radial pulsation limits the upper mass of a star

  18. 21 CFR 866.4800 - Radial immunodiffusion plate.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunology Laboratory Equipment and Reagents § 866.4800 Radial immunodiffusion plate. (a) Identification. A radial immunodiffusion plate for clinical use...

  19. Stochastic Evaluation of Maximum Wind Installation in a Radial Distribution Network

    DEFF Research Database (Denmark)

    Chen, Peiyuan; Bak-Jensen, Birgitte; Chen, Zhe

    2011-01-01

    This paper proposes an optimization algorithm to find the maximum wind installation in a radial distribution network. The algorithm imposes a limit on the amount of wind energy that can be curtailed annually. The algorithm implements the wind turbine reactive power control and wind energy...... curtailment using sensitivity factors. The optimization is integrated with Monte Carlo simulation to account for the stochastic behavior of load demand and wind power generation. The proposed algorithm is tested on a real 20 kV Danish distribution system in Støvring. It is demonstrated that the algorithm...... executes reactive compensation and energy curtailment sequentially in an effective and efficient manner....

  20. Lace expansion for dummies

    NARCIS (Netherlands)

    Bolthausen, Erwin; Van Der Hofstad, Remco; Kozma, Gady

    2018-01-01

    We show Green's function asymptotic upper bound for the two-point function of weakly self-Avoiding walk in d >4, revisiting a classic problem. Our proof relies on Banach algebras to analyse the lace-expansion fixed point equation and is simpler than previous approaches in that it avoids Fourier

  1. OPEC future capacity expansions

    International Nuclear Information System (INIS)

    Sandrea, I.

    2005-01-01

    This conference presentation examined OPEC future capacity expansions including highlights from 2000-2004 from the supply perspective and actions by OPEC; OPEC spare capacity in 2005/2006; medium-term capacity expansion and investments; long-term scenarios, challenges and opportunities; and upstream policies in member countries. Highlights from the supply perspective included worst than expected non-OPEC supply response; non-OPEC supply affected by a number of accidents and strikes; geopolitical tensions; and higher than expected demand for OPEC crude. OPEC's actions included closer relationship with other producers and consumers; capacity expansions in 2004 and 2005/2006; and OPEC kept the market well supplied with crude in 2004. The presentation also provided data using graphical charts on OPEC net capacity additions until 2005/2006; OPEC production versus spare capacity from 2003 to 2005; OPEC production and capacity to 2010; and change in required OPEC production from 2005-2020. Medium term expansion to 2010 includes over 60 projects. Medium-term risks such as project execution, financing, costs, demand, reserves, depletion, integration of Iraq, and geopolitical tensions were also discussed. The presentation concluded that in the long term, large uncertainties remain; the peak of world supply is not imminent; and continued and enhanced cooperation is essential to market stability. tabs., figs

  2. Temperature and boron dependencies of buckling and radial reflector saving for VVER lattices

    International Nuclear Information System (INIS)

    Alvarez, C.

    1990-01-01

    The temperature and boron dependencies of buckling and radial reflectors savings are analyzed in this paper on the basis of the results from the calculations ZR-6M critical assembly. These dependencies are related to the physical behavior of temperature and boron reactivity coefficients for the cores of VVER-type critical facilities. As a byproduct, the parameter was also investigated and its dependence on water density was determined

  3. Temperature and boron dependencies of buckling and radial reflector savings for VVER lattices

    International Nuclear Information System (INIS)

    Alvarez, C.

    1990-01-01

    The temperature and boron dependencies of buckling and radial reflector savings are analyzed in this paper on the basis of the results from the calculations for the ZR-6M critical assembly. These dependencies are related to he physical behaviour of temperature and boron reactivity coefficients for the cores of VVER-type critical facilities. As a byproduct, the dp/dBg 2 parameter was also investigated and its dependence on water density was determined

  4. Population Genetics of Three Dimensional Range Expansions

    Science.gov (United States)

    Lavrentovich, Maxim; Nelson, David

    2014-03-01

    We develop a simple model of genetic diversity in growing spherical cell clusters, where the growth is confined to the cluster surface. This kind of growth occurs in cells growing in soft agar, and can also serve as a simple model of avascular tumors. Mutation-selection balance in these radial expansions is strongly influenced by scaling near a neutral, voter model critical point and by the inflating frontier. We develop a scaling theory to describe how the dynamics of mutation-selection balance is cut off by inflation. Genetic drift, i.e., local fluctuations in the genetic diversity, also plays an important role, and can lead to the extinction even of selectively advantageous strains. We calculate this extinction probability, taking into account the effect of rough population frontiers.

  5. The reactivity meter and core reactivity

    International Nuclear Information System (INIS)

    Siltanen, P.

    1999-01-01

    This paper discussed in depth the point kinetic equations and the characteristics of the point kinetic reactivity meter, particularly for large negative reactivities. From a given input signal representing the neutron flux seen by a detector, the meter computes a value of reactivity in dollars (ρ/β), based on inverse point kinetics. The prompt jump point of view is emphasised. (Author)

  6. Effects of pillar height and junction depth on the performance of radially doped silicon pillar arrays for solar energy applications

    NARCIS (Netherlands)

    Elbersen, R.; Vijselaar, Wouter Jan, Cornelis; Tiggelaar, Roald M.; Gardeniers, Johannes G.E.; Huskens, Jurriaan

    2016-01-01

    The effects of pillar height and junction depth on solar cell characteristics are investigated to provide design rules for arrays of such pillars in solar energy applications. Radially doped silicon pillar arrays are fabricated by deep reactive ion etching of silicon substrates followed by the

  7. Reactive power compensation and loss reduction in large industrial enterprises

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, S; Gajic, B; Mijailovic, S [Institute Nikola Tesla, Beograd (Yugoslavia)

    1991-12-01

    This paper considers the reactive power compensation and the active power and energy loss reduction of large radial power networks in the Serbian mine and smelting industry. It gives an efficient optimization procedure for positioning and sizing capacitors in large industrial systems integrated with a simple network analysis method. (Author).

  8. Anomalies of radial and ulnar arteries

    Directory of Open Access Journals (Sweden)

    Rajani Singh

    Full Text Available Abstract During dissection conducted in an anatomy department of the right upper limb of the cadaver of a 70-year-old male, both origin and course of the radial and ulnar arteries were found to be anomalous. After descending 5.5 cm from the lower border of the teres major, the brachial artery anomalously bifurcated into a radial artery medially and an ulnar artery laterally. In the arm, the ulnar artery lay lateral to the median nerve. It followed a normal course in the forearm. The radial artery was medial to the median nerve in the arm and then, at the level of the medial epicondyle, it crossed from the medial to the lateral side of the forearm, superficial to the flexor muscles. The course of the radial artery was superficial and tortuous throughout the arm and forearm. The variations of radial and ulnar arteries described above were associated with anomalous formation and course of the median nerve in the arm. Knowledge of neurovascular anomalies are important for vascular surgeons and radiologists.

  9. Discrete imaging models for three-dimensional optoacoustic tomography using radially symmetric expansion functions.

    Science.gov (United States)

    Wang, Kun; Schoonover, Robert W; Su, Richard; Oraevsky, Alexander; Anastasio, Mark A

    2014-05-01

    Optoacoustic tomography (OAT), also known as photoacoustic tomography, is an emerging computed biomedical imaging modality that exploits optical contrast and ultrasonic detection principles. Iterative image reconstruction algorithms that are based on discrete imaging models are actively being developed for OAT due to their ability to improve image quality by incorporating accurate models of the imaging physics, instrument response, and measurement noise. In this work, we investigate the use of discrete imaging models based on Kaiser-Bessel window functions for iterative image reconstruction in OAT. A closed-form expression for the pressure produced by a Kaiser-Bessel function is calculated, which facilitates accurate computation of the system matrix. Computer-simulation and experimental studies are employed to demonstrate the potential advantages of Kaiser-Bessel function-based iterative image reconstruction in OAT.

  10. PhCESA3 silencing inhibits elongation and stimulates radial expansion in petunia

    OpenAIRE

    Weiyuan Yang; Yuanping Cai; Li Hu; Qian Wei; Guoju Chen; Mei Bai; Hong Wu; Juanxu Liu; Yixun Yu

    2017-01-01

    Cellulose synthase catalytic subunits (CESAs) play important roles in plant growth, development and disease resistance. Previous studies have shown an essential role of Arabidopsis thaliana CESA3 in plant growth. However, little is known about the role of CESA3 in species other than A. thaliana. To gain a better understanding of CESA3, the petunia (Petunia hybrida) PhCESA3 gene was isolated, and the role of PhCESA3 in plant growth was analyzed in a wide range of plants. PhCESA3 mRNA was prese...

  11. Expansion at Olympic Dam

    International Nuclear Information System (INIS)

    Lewis, C.

    1997-01-01

    The Olympic Dam orebody is the 6th largest copper and the single largest uranium orebody in the world. Mine production commenced in June 1988, at an annual production rate of around 45,000 tonnes of copper and 1,000 tonnes of uranium. Western Mining Corporation announced in 1996 a proposed $1.25 billion expansion of the Olympic Dam operation to raise the annual production capacity of the mine to 200,000 tonnes of copper, approximately 3,700 tonnes of uranium, 75,000 ounces of gold and 950,000 ounces of silver by 2001. Further optimisation work has identified a faster track expansion route, with an increase in the capital cost to $1.487 billion but improved investment outcome, a new target completion date of end 1999, and a new uranium output of 4,600 tonnes per annum from that date

  12. Financing electricity expansion

    International Nuclear Information System (INIS)

    Hyman, L.S.

    1994-01-01

    Expansion of electricity supply is associated with economic development. The installation and enlargement of power systems in developing countries entails a huge financial burden, however. Energy consumers in such countries must pay not only for supplies but for the cost of raising the capital for expansion on the international markets. Estimates are presented for the capital expenditure for electricity supply over the period 1990 to 2020 for the major world regions, using approximations for the cost of plant and capital and for the returns earned. These data lead to the conclusion that the five regions with the lowest per capita incomes are those which will need the major part of the capital expenditure and the highest percentage of external finance. (6 tables) (UK)

  13. Bigravity from gradient expansion

    International Nuclear Information System (INIS)

    Yamashita, Yasuho; Tanaka, Takahiro

    2016-01-01

    We discuss how the ghost-free bigravity coupled with a single scalar field can be derived from a braneworld setup. We consider DGP two-brane model without radion stabilization. The bulk configuration is solved for given boundary metrics, and it is substituted back into the action to obtain the effective four-dimensional action. In order to obtain the ghost-free bigravity, we consider the gradient expansion in which the brane separation is supposed to be sufficiently small so that two boundary metrics are almost identical. The obtained effective theory is shown to be ghost free as expected, however, the interaction between two gravitons takes the Fierz-Pauli form at the leading order of the gradient expansion, even though we do not use the approximation of linear perturbation. We also find that the radion remains as a scalar field in the four-dimensional effective theory, but its coupling to the metrics is non-trivial.

  14. Expansion of magnetic clouds

    International Nuclear Information System (INIS)

    Suess, S.T.

    1987-01-01

    Magnetic clouds are a carefully defined subclass of all interplanetary signatures of coronal mass ejections whose geometry is thought to be that of a cylinder embedded in a plane. It has been found that the total magnetic pressure inside the clouds is higher than the ion pressure outside, and that the clouds are expanding at 1 AU at about half the local Alfven speed. The geometry of the clouds is such that even though the magnetic pressure inside is larger than the total pressure outside, expansion will not occur because the pressure is balanced by magnetic tension - the pinch effect. The evidence for expansion of clouds at 1 AU is nevertheless quite strong so another reason for its existence must be found. It is demonstrated that the observations can be reproduced by taking into account the effects of geometrical distortion of the low plasma beta clouds as they move away from the Sun

  15. IKEA's International Expansion

    OpenAIRE

    Harapiak, Clayton

    2013-01-01

    This case concerns a global retailing firm that is dealing with strategic management and marketing issues. Applying a scenario of international expansion, this case provides a thorough analysis of the current business environment for IKEA. Utilizing a variety of methods (e.g. SWOT, PESTLE, McKinsey Matrix) the overall objective is to provide students with the opportunity to apply their research skills and knowledge regarding a highly competitive industry to develop strategic marketing strateg...

  16. Symmetric eikonal expansion

    International Nuclear Information System (INIS)

    Matsuki, Takayuki

    1976-01-01

    Symmetric eikonal expansion for the scattering amplitude is formulated for nonrelativistic and relativistic potential scatterings and also for the quantum field theory. The first approximations coincide with those of Levy and Sucher. The obtained scattering amplitudes are time reversal invariant for all cases and are crossing symmetric for the quantum field theory in each order of approximation. The improved eikonal phase introduced by Levy and Sucher is also derived from the different approximation scheme from the above. (auth.)

  17. Series expansions without diagrams

    International Nuclear Information System (INIS)

    Bhanot, G.; Creutz, M.; Horvath, I.; Lacki, J.; Weckel, J.

    1994-01-01

    We discuss the use of recursive enumeration schemes to obtain low- and high-temperature series expansions for discrete statistical systems. Using linear combinations of generalized helical lattices, the method is competitive with diagrammatic approaches and is easily generalizable. We illustrate the approach using Ising and Potts models. We present low-temperature series results in up to five dimensions and high-temperature series in three dimensions. The method is general and can be applied to any discrete model

  18. Physical mechanism determining the radial electric field and its radial structure in a toroidal plasma

    International Nuclear Information System (INIS)

    Ida, Katsumi; Miura, Yukitoshi; Itoh, Sanae

    1994-10-01

    Radial structures of plasma rotation and radial electric field are experimentally studied in tokamak, heliotron/torsatron and stellarator devices. The perpendicular and parallel viscosities are measured. The parallel viscosity, which is dominant in determining the toroidal velocity in heliotron/torsatron and stellarator devices, is found to be neoclassical. On the other hand, the perpendicular viscosity, which is dominant in dictating the toroidal rotation in tokamaks, is anomalous. Even without external momentum input, both a plasma rotation and a radial electric field exist in tokamaks and heliotrons/torsatrons. The observed profiles of the radial electric field do not agree with the theoretical prediction based on neoclassical transport. This is mainly due to the existence of anomalous perpendicular viscosity. The shear of the radial electric field improves particle and heat transport both in bulk and edge plasma regimes of tokamaks. (author) 95 refs

  19. Manufacturing of Precision Forgings by Radial Forging

    International Nuclear Information System (INIS)

    Wallner, S.; Harrer, O.; Buchmayr, B.; Hofer, F.

    2011-01-01

    Radial forging is a multi purpose incremental forging process using four tools on the same plane. It is widely used for the forming of tool steels, super alloys as well as titanium- and refractory metals. The range of application goes from reducing the diameters of shafts, tubes, stepped shafts and axels, as well as for creating internal profiles for tubes in Near-Net-Shape and Net-Shape quality. Based on actual development of a weight optimized transmission input shaft, the specific features of radial forging technology is demonstrated. Also a Finite Element Model for the simulation of the process is shown which leads to reduced pre-processing effort and reduced computing time compared to other published simulation methods for radial forging. The finite element model can be applied to quantify the effects of different forging strategies.

  20. Power flattening and reactivity suppression strategies for the Canadian supercritical water reactor concept

    International Nuclear Information System (INIS)

    McDonald, M.; Colton, A.; Pencer, J.

    2015-01-01

    The Canadian supercritical water-cooled reactor (SCWR) is a conceptual heavy water moderated, supercritical light water cooled pressure tube reactor. In contrast to current heavy water power reactors, the Canadian SCWR will be a batch fuelled reactor. Associated with batch fuelling is a large beginning-of-cycle excess reactivity. Furthermore, radial power peaking arising as a consequence of batch refuelling must be mitigated in some way. In this paper, burnable neutron absorber (BNA) added to fuel and absorbing rods inserted into the core are considered for reactivity management and power flattening. A combination of approaches appears adequate to reduce the core radial power peaking, while also providing reactivity suppression. (author)

  1. The Matlab Radial Basis Function Toolbox

    Directory of Open Access Journals (Sweden)

    Scott A. Sarra

    2017-03-01

    Full Text Available Radial Basis Function (RBF methods are important tools for scattered data interpolation and for the solution of Partial Differential Equations in complexly shaped domains. The most straight forward approach used to evaluate the methods involves solving a linear system which is typically poorly conditioned. The Matlab Radial Basis Function toolbox features a regularization method for the ill-conditioned system, extended precision floating point arithmetic, and symmetry exploitation for the purpose of reducing flop counts of the associated numerical linear algebra algorithms.

  2. Radial velocity observations of VB10

    Science.gov (United States)

    Deshpande, R.; Martin, E.; Zapatero Osorio, M. R.; Del Burgo, C.; Rodler, F.; Montgomery, M. M.

    2011-07-01

    VB 10 is the smallest star known to harbor a planet according to the recent astrometric study of Pravdo & Shaklan [1]. Here we present near-infrared (J-band) radial velocity of VB 10 performed from high resolution (R~20,000) spectroscopy (NIRSPEC/KECK II). Our results [2] suggest radial velocity variability with amplitude of ~1 km/s, a result that is consistent with the presence of a massive planet companion around VB10 as found via long-term astrometric monitoring of the star by Pravdo & Shaklan. Employing an entirely different technique we verify the results of Pravdo & Shaklan.

  3. Plasma Signatures of Radial Field Power Dropouts

    International Nuclear Information System (INIS)

    Lucek, E.A.; Horbury, T.S.; Balogh, A.; McComas, D.J.

    1998-01-01

    A class of small scale structures, with a near-radial magnetic field and a drop in magnetic field fluctuation power, have recently been identified in the polar solar wind. An earlier study of 24 events, each lasting for 6 hours or more, identified no clear plasma signature. In an extension of that work, radial intervals lasting for 4 hours or more (89 in total), have been used to search for a statistically significant plasma signature. It was found that, despite considerable variations between intervals, there was a small but significant drop, on average, in plasma temperature, density and β during these events

  4. Reble, a radially converging electron beam accelerator

    International Nuclear Information System (INIS)

    Ramirez, J.J.; Prestwich, K.R.

    1976-01-01

    The Reble accelerator at Sandia Laboratories is described. This accelerator was developed to provide an experimental source for studying the relevant diode physics, beam propagation, beam energy deposition in a gas using a radially converging e-beam. The nominal parameters for Reble are 1 MV, 200 kA, 20 ns e-beam pulse. The anode and cathode are concentric cylinders with the anode as the inner cylinder. The radial beam can be propagated through the thin foil anode into the laser gas volume. The design and performance of the various components of the accelerator are presented

  5. Expansions for Coulomb wave functions

    NARCIS (Netherlands)

    Boersma, J.

    1969-01-01

    In this paper we derive a number of expansions for Whittaker functions, regular and irregular Coulomb wave functions. The main result consists of a new expansion for the irregular Coulomb wave functions of orders zero and one in terms of regular Coulomb wave functions. The latter expansions are

  6. On helicon wave induced radial plasma transport

    International Nuclear Information System (INIS)

    Petrzilka, V.

    1993-04-01

    Estimates of helicon wave induced radial plasma transport are presented. The wave induced transport grows or decreases in dependence on the sign of the azimuthal wave number; these changes in transport may play an important role in helicon wave plasma sources. (author) 5 figs., 18 refs

  7. Revealing the radial modes in vortex beams

    CSIR Research Space (South Africa)

    Sephton, Bereneice C

    2016-10-01

    Full Text Available Light beams that carry orbital angular momentum are often approximated by modulating an initial beam, usually Gaussian, with an azimuthal phase variation to create a vortex beam. Such vortex beams are well defined azimuthally, but the radial profile...

  8. Measurement of Wear in Radial Journal Bearings

    NARCIS (Netherlands)

    Ligterink, D.J.; Ligterink, D.J.; de Gee, A.W.J.

    1996-01-01

    this article, the measurement of wear in radial journal bearings is discussed, where a distinction is made between stationary and non-stationary contact conditions. Starting with Holm/Archard's wear law, equations are derived for the calculation of the specific wear rate k of the bearing material as

  9. Radial interchange motions of plasma filaments

    DEFF Research Database (Denmark)

    Garcia, O.E.; Bian, N.H.; Fundamenski, W.

    2006-01-01

    on a biperiodic domain perpendicular to the magnetic field. It is demonstrated that a blob-like plasma structure develops dipolar vorticity and electrostatic potential fields, resulting in rapid radial acceleration and formation of a steep front and a trailing wake. While the dynamical evolution strongly depends...

  10. Radial transfer effects for poloidal rotation

    Science.gov (United States)

    Hallatschek, Klaus

    2010-11-01

    Radial transfer of energy or momentum is the principal agent responsible for radial structures of Geodesic Acoustic Modes (GAMs) or stationary Zonal Flows (ZF) generated by the turbulence. For the GAM, following a physical approach, it is possible to find useful expressions for the individual components of the Poynting flux or radial group velocity allowing predictions where a mathematical full analysis is unfeasible. Striking differences between up-down symmetric flux surfaces and asymmetric ones have been found. For divertor geometries, e.g., the direction of the propagation depends on the sign of the ion grad-B drift with respect to the X-point, reminiscent of a sensitive determinant of the H-mode threshold. In nonlocal turbulence computations it becomes obvious that the linear energy transfer terms can be completely overwhelmed by the action of the turbulence. In contrast, stationary ZFs are governed by the turbulent radial transfer of momentum. For sufficiently large systems, the Reynolds stress becomes a deterministic functional of the flows, which can be empirically determined from the stress response in computational turbulence studies. The functional allows predictions even on flow/turbulence states not readily obtainable from small amplitude noise, such as certain transport bifurcations or meta-stable states.

  11. Spectral problem for the radial Schroedinger equation

    International Nuclear Information System (INIS)

    Vshivtsev, A.S.; Tatarintsev, A.V.; Prokopov, A.V.; Sorokin, V. N.

    1998-01-01

    For the first time, a procedure for determining spectra on the basis of generalized integral transformations is implemented for a wide class of radial Schroedinger equations. It is shown that this procedure works well for known types of potentials. Concurrently, this method makes it possible to obtain new analytic results for the Cornell potential. This may prove important for hadron physics

  12. Computing modal dispersion characteristics of radially Asymmetric ...

    African Journals Online (AJOL)

    We developed a matrix theory that applies to with non-circular/circular but concentric layers fibers. And we compute the dispersion characteristics of radially unconventional fiber, known as Asymmetric Bragg fiber. An attempt has been made to determine how the modal characteristics change as circular Bragg fiber is ...

  13. Rethinking expansive learning

    DEFF Research Database (Denmark)

    Kolbæk, Ditte; Lundh Snis, Ulrika

    Abstract: This paper analyses an online community of master’s students taking a course in ICT and organisational learning. The students initiated and facilitated an educational design for organisational learning called Proactive Review in the organisation where they are employed. By using an online...... discussion forum on Google groups, they created new ways of reflecting and learning. We used netnography to select qualitative postings from the online community and expansive learning concepts for data analysis. The findings show how students changed practices of organisational learning...

  14. Load regulating expansion fixture

    International Nuclear Information System (INIS)

    Wagner, L.M.; Strum, M.J.

    1998-01-01

    A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils is disclosed. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located there between. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components. 1 fig

  15. Variations in the usage and composition of a radial cocktail during radial access coronary angiography procedures.

    LENUS (Irish Health Repository)

    Pate, G

    2011-10-01

    A survey was conducted of medication administered during radial artery cannulation for coronary angiography in 2009 in Ireland; responses were obtained for 15 of 20 centres, in 5 of which no radial access procedures were undertaken. All 10 (100%) centres which provided data used heparin and one or more anti-spasmodics; verapamil in 9 (90%), nitrate in 1 (10%), both in 2 (20%). There were significant variations in the doses used. Further work needs to be done to determine the optimum cocktail to prevent radial artery injury following coronary angiography.

  16. Radial wave crystals: radially periodic structures from anisotropic metamaterials for engineering acoustic or electromagnetic waves.

    Science.gov (United States)

    Torrent, Daniel; Sánchez-Dehesa, José

    2009-08-07

    We demonstrate that metamaterials with anisotropic properties can be used to develop a new class of periodic structures that has been named radial wave crystals. They can be sonic or photonic, and wave propagation along the radial directions is obtained through Bloch states like in usual sonic or photonic crystals. The band structure of the proposed structures can be tailored in a large amount to get exciting novel wave phenomena. For example, it is shown that acoustical cavities based on radial sonic crystals can be employed as passive devices for beam forming or dynamically orientated antennas for sound localization.

  17. Thermal expansion of granite rocks

    International Nuclear Information System (INIS)

    Stephansson, O.

    1978-04-01

    The thermal expansion of rocks is strongly controlled by the thermal expansion of the minerals. The theoretical thermal expansion of the Stripa Granite is gound to be 21 . 10 -6 [deg C] -1 at 25 deg C and 38 . 10 -6 [deg C] -1 at 400 deg C. The difference in expansion for the rock forming minerals causes micro cracking at heating. The expansion due to micro cracks is found to be of the same order as the mineral expansion. Most of the micro cracks will close at pressures of the order of 10 - 20 MPa. The thermal expansion of a rock mass including the effect of joints is determined in the pilot heater test in the Stripa Mine

  18. Provincial hydro expansions

    Energy Technology Data Exchange (ETDEWEB)

    Froschauer, K J

    1993-01-01

    A study of the development of five provincial hydroelectric utilities in Canada indicates that power companies and the state invited manufacturers to use hydroelectricity and natural resources in order to diversify provincial economies. These hydro expansions also show that utilities and government designed hydro projects to serve continental requirements; serving both objectives became problematic. It is argued that when the Canadian state and firms such as utilities use hydro expansions to serve both continentalism and industrialization, then at best they foster dependent industrialization and staple processing. At worst, they overbuild the infrastructure to generate provincial surplus energy for continental, rather than national, integration. Hydro developments became subject to state intervention in Canada mainly through the failures of private utilities to provide power for the less-lucrative industrial markets within provincial subregions. Although the state and utilities invited foreign firms to manufacture hydro equipment within the provinces and others to use electricity to diversify production beyond resource processing, such a diversification did not occur. Since 1962, ca 80% of industrial energy was used to semi-process wood-derived products, chemicals, and metals. The idea for a national power network became undermined by interprovincial political-economic factors and since 1963, the federal national/continential power policy prevailed. 187 refs., 6 figs., 52 tabs.

  19. Measuring of tube expansion

    International Nuclear Information System (INIS)

    Vogeleer, J. P.

    1985-01-01

    The expansion of the primary tubes or sleeves of the steam generator of a nuclear reactor plant are measured while the tubes or sleeves are being expanded. A primary tube or sleeve is expanded by high pressure of water which flows through a channel in an expander body. The water is supplied through an elongated conductor and is introduced through a connector on the shank connected to the conductor at its outer end. A wire extends through the mandrel and through the conductor to the end of the connector. At its inner end the wire is connected to a tapered pin which is subject to counteracting forces produced by the pressure of the water. The force on the side where the wire is connected to the conductor is smaller than on the opposite side. The tapered pin is moved in the direction of the higher force and extrudes the wire outwardly of the conductor. The tapered surface of the tapered pin engages transverse captive plungers which are maintained in engagement with the expanding tube or sleeve as they are moved outwardly by the tapered pin. The wire and the connector extend out of the generator and, at its outer end, the wire is connected to an indicator which measures the extent to which the wire is moved by the tapered pin, thus measuring the expansion of the tube or sleeve as it progresses

  20. Fuel-steel mixing and radial mesh effects in power excursion simulations

    International Nuclear Information System (INIS)

    Chen, X.-N.; Rineiski, A.; Gabrielli, F.; Andriolo, L.; Vezzoni, B.; Li, R.; Maschek, W.; Kiefhaber, E.

    2016-01-01

    Highlights: • Fuel-steel mixing and radial mesh effects are significant on power excursion. • The earliest power peak is reduced and retarded by these two effects. • Unprotected loss of coolant transients in ESFR core are calculated. - Abstract: This paper deals with SIMMER-III once-through simulations of the earliest power excursion initiated by an unprotected loss of flow (ULOF) in the Working Horse design of the European Sodium Cooled Fast Reactor (ESFR). Since the sodium void effect is strictly positive in this core and dominant in the transient, a power excursion is initiated by sodium boiling in the ULOF case. Two major effects, namely (1) reactivity effects due to fuel-steel mixing after melting and (2) the radial mesh size, which were not considered originally in SIMMER simulations for ESFR, are studied. The first effect concerns the reactivity difference between the heterogeneous fuel/clad/wrapper configuration and the homogeneous mixture of steel and fuel. The full core homogenization (due to melting) effect is −2 $, though a smaller effect takes place in case of partial core melting. The second effect is due to the SIMMER sub-assembly (SA) coarse mesh treatment, where a simultaneous sodium boiling onset in all SAs belonging to one ring leads to an overestimated reactivity ramp. For investigating the influence of fuel/steel mixing effects, a lumped “homogenization” reactivity feedback has been introduced, being proportional to the molten steel mass. For improving the coarse mesh treatment, we employ finer radial meshes to take the subchannel effects into account, where the side and interior channels have different coolant velocities and temperatures. The simulation results show that these two effects have significant impacts on the earliest power excursion after the sodium boiling.

  1. Reactive Kripke semantics

    CERN Document Server

    Gabbay, Dov M

    2013-01-01

    This text offers an extension to the traditional Kripke semantics for non-classical logics by adding the notion of reactivity. Reactive Kripke models change their accessibility relation as we progress in the evaluation process of formulas in the model. This feature makes the reactive Kripke semantics strictly stronger and more applicable than the traditional one. Here we investigate the properties and axiomatisations of this new and most effective semantics, and we offer a wide landscape of applications of the idea of reactivity. Applied topics include reactive automata, reactive grammars, rea

  2. Radial optimization of a BWR fuel cell using genetic algorithms; Optimizacion radial de una celda de combustible BWR usando algoritmos geneticos

    Energy Technology Data Exchange (ETDEWEB)

    Martin del Campo M, C.; Carmona H, R.; Oropeza C, I.P. [UNAM, Paseo Cuauhnahuac 8532, 62550 Jiutepec, Morelos (Mexico)]. e-mail: cmcm@fi-b.unam.mx

    2006-07-01

    the placement of the bars of water, were applied. However the placement of the bars with gadolinia inside the cell was free. The obtained results were excellent, its were found forty designs that fulfill the wanted reactivity and the peak factor of radial power. The best of them has an neutron acting superior to the design of the reference cell using an average smaller enrichment. (Author)

  3. Modelling The Effects of Aggregate Size on Alkali Aggregate Reaction Expansion

    Directory of Open Access Journals (Sweden)

    N. Z. Sekrane

    2014-06-01

    Full Text Available This work aims at developing models to predict the potential expansion of concrete containing alkali-reactive aggregates. The paper gives measurements in order to provide experimental data concerning the effect of particle size of an alkali-reactive siliceous limestone on mortar expansion. Results show that no expansion was measured on the mortars using small particles (0.5-1.0 mm while the particles (1.0–2.0 mm gave the largest expansions (0.217%. Two models are proposed, the first one studies the correlations between the measured expansions and the size of aggregates, the second one calculates the thickness of the porous zone necessary to take again all the volume of the gel created.

  4. Thermal expansion of coking coals

    Energy Technology Data Exchange (ETDEWEB)

    Orlik, M.; Klimek, J. (Vyzkumny a Zkusebni Ustav Nova Hut, Ostrava (Czechoslovakia))

    1992-12-01

    Analyzes expansion of coal mixtures in coke ovens during coking. Methods for measuring coal expansion on both a laboratory and pilot plant scale are comparatively evaluated. The method, developed, tested and patented in Poland by the Institute for Chemical Coal Processing in Zabrze (Polish standard PN-73/G-04522), is discussed. A laboratory device developed by the Institute for measuring coal expansion is characterized. Expansion of black coal from 10 underground mines in the Ostrava-Karvina coal district and from 9 coal mines in the Upper Silesia basin in Poland is comparatively evaluated. Investigations show that coal expansion reaches a maximum for coal types with a volatile matter ranging from 20 to 25%. With increasing volatile matter in coal, its expansion decreases. Coal expansion increases with increasing swelling index. Coal expansion corresponds with coal dilatation. With increasing coal density its expansion increases. Coal mixtures should be selected in such a way that their expansion does not cause a pressure exceeding 40 MPa. 11 refs.

  5. Identity Expansion and Transcendence

    Directory of Open Access Journals (Sweden)

    William Sims Bainbridge

    2014-05-01

    Full Text Available Emerging developments in communications and computing technology may transform the nature of human identity, in the process rendering obsolete the traditional philosophical and scientific frameworks for understanding the nature of individuals and groups.  Progress toward an evaluation of this possibility and an appropriate conceptual basis for analyzing it may be derived from two very different but ultimately connected social movements that promote this radical change. One is the governmentally supported exploration of Converging Technologies, based in the unification of nanoscience, biology, information science and cognitive science (NBIC. The other is the Transhumanist movement, which has been criticized as excessively radical yet is primarily conducted as a dignified intellectual discussion within a new school of philosophy about human enhancement.  Together, NBIC and Transhumanism suggest the immense transformative power of today’s technologies, through which individuals may explore multiple identities by means of online avatars, semi-autonomous intelligent agents, and other identity expansions.

  6. WWER radial reflector modeling by diffusion codes

    International Nuclear Information System (INIS)

    Petkov, P. T.; Mittag, S.

    2005-01-01

    The two commonly used approaches to describe the WWER radial reflectors in diffusion codes, by albedo on the core-reflector boundary and by a ring of diffusive assembly size nodes, are discussed. The advantages and disadvantages of the first approach are presented first, then the Koebke's equivalence theory is outlined and its implementation for the WWER radial reflectors is discussed. Results for the WWER-1000 reactor are presented. Then the boundary conditions on the outer reflector boundary are discussed. The possibility to divide the library into fuel assembly and reflector parts and to generate each library by a separate code package is discussed. Finally, the homogenization errors for rodded assemblies are presented and discussed (Author)

  7. Oculoauriculovertebral spectrum with radial anomaly in child.

    Science.gov (United States)

    Taksande, Amar; Vilhekar, Krishna

    2013-01-01

    Oculoauriculovertebral spectrum (OAVS) or Goldenhar syndrome is a wide spectrum of congenital anomalies that involves structures arising from the first and second branchial arches. It is characterized by a wide spectrum of symptoms and physical features. These abnormalities mainly involve the cheekbones, jaws, mouth, ears, eyes, or vertebrae. Other conditions with ear and/or radial involvement, such as, the Nager syndrome, Holt-Oram syndrome, Radial-renal syndrome, facioauriculoradial dysplasia, Fanconi anemia, and Vertebral, Anal atresia, Cardiac, Trachea, Esophageal, Renal, and Limb (VACTERL) association should be considered for differential diagnosis. Here we report a child who had facial asymmetry, microsomia, microtia, congenital facial nerve palsy, conductive hearing loss, skin tags, iris coloboma, and preaxial polydactyly.

  8. Oculoauriculovertebral spectrum with radial anomaly in child

    Directory of Open Access Journals (Sweden)

    Amar Taksande

    2013-01-01

    Full Text Available Oculoauriculovertebral spectrum (OAVS or Goldenhar syndrome is a wide spectrum of congenital anomalies that involves structures arising from the first and second branchial arches. It is characterized by a wide spectrum of symptoms and physical features. These abnormalities mainly involve the cheekbones, jaws, mouth, ears, eyes, or vertebrae. Other conditions with ear and/or radial involvement, such as, the Nager syndrome, Holt-Oram syndrome, Radial-renal syndrome, facioauriculoradial dysplasia, Fanconi anemia, and Vertebral, Anal atresia, Cardiac, Trachea, Esophageal, Renal, and Limb (VACTERL association should be considered for differential diagnosis. Here we report a child who had facial asymmetry, microsomia, microtia, congenital facial nerve palsy, conductive hearing loss, skin tags, iris coloboma, and preaxial polydactyly.

  9. Linear radial pulsation theory. Lecture 5

    International Nuclear Information System (INIS)

    Cox, A.N.

    1983-01-01

    We describe a method for getting an equilibrium stellar envelope model using as input the total mass, the envelope mass, the surface effective temperature, the total surface luminosity, and the composition of the envelope. Then wih the structure of the envelope model known, we present a method for obtaining the raidal pulsation periods and growth rates for low order modes. The large amplitude pulsations observed for the yellow and red giants and supergiants are always these radial models, but for the stars nearer the main sequence, as for all of our stars and for the white dwarfs, there frequently are nonradial modes occuring also. Application of linear theory radial pulsation theory is made to the giant star sigma Scuti variables, while the linear nonradial theory will be used for the B stars in later lectures

  10. SpicyNodes Radial Map Engine

    Science.gov (United States)

    Douma, M.; Ligierko, G.; Angelov, I.

    2008-10-01

    The need for information has increased exponentially over the past decades. The current systems for constructing, exploring, classifying, organizing, and searching information face the growing challenge of enabling their users to operate efficiently and intuitively in knowledge-heavy environments. This paper presents SpicyNodes, an advanced user interface for difficult interaction contexts. It is based on an underlying structure known as a radial map, which allows users to manipulate and interact in a natural manner with entities called nodes. This technology overcomes certain limitations of existing solutions and solves the problem of browsing complex sets of linked information. SpicyNodes is also an organic system that projects users into a living space, stimulating exploratory behavior and fostering creative thought. Our interactive radial layout is used for educational purposes and has the potential for numerous other applications.

  11. Stability of a radial immiscible drive

    Energy Technology Data Exchange (ETDEWEB)

    Bataille, J

    1968-11-01

    The stability of the displacement front between 2 immiscible fluids of radial flow between 2 parallel plates (Hele-Shaw model) is studied mathematically by superposing onto the circular displacement front a sinusoidal perturbation. The equations are reduced to dimensionless variables, and it is shown that the stable and unstable domains in a plot: dimensionless viscosity vs. dimensionless time are separated by a polygonal contour, each side of the contour being characterized by the (integer) number of perturbations along the circumference. There is a critical reduced time below which the perturbations are amortized but beyond which they are amplified. Experimental results have been in fair general agreement with theoretical results, the divergence between them being attributable to neglecting capillary phenomena, which may become very important at large radial distances. One test with miscible fluids has shown that even in this case, there is a critical time or an equivalent critical radius.

  12. Reactive perforating collagenosis

    Directory of Open Access Journals (Sweden)

    Yadav Mukesh

    2009-01-01

    Full Text Available Reactive perforating collagenosis is a rare cutaneous disorder of unknown etiology. We hereby describe a case of acquired reactive perforating collagenosis in a patient of diabetes and chronic renal failure.

  13. Radial oxygen gradients over rat cortex arterioles

    OpenAIRE

    Galler, Michael

    2011-01-01

    Purpose: We present the results of the visualisation of radial oxygen gradients in rats’ cortices and their use in neurocritical management. Methods: PO2 maps of the cortex of 10 wistar rats were obtained with a camera (SensiMOD, PCO, Kehlheim, Germany). Those pictures were analyzed and edited by a custom-made software. We chose a vessel for examination. A matrix, designed to evaluate the cortical O2 partial pressure, was placed vertically to the artery and afterwards multiple regio...

  14. Variational method for integrating radial gradient field

    Science.gov (United States)

    Legarda-Saenz, Ricardo; Brito-Loeza, Carlos; Rivera, Mariano; Espinosa-Romero, Arturo

    2014-12-01

    We propose a variational method for integrating information obtained from circular fringe pattern. The proposed method is a suitable choice for objects with radial symmetry. First, we analyze the information contained in the fringe pattern captured by the experimental setup and then move to formulate the problem of recovering the wavefront using techniques from calculus of variations. The performance of the method is demonstrated by numerical experiments with both synthetic and real data.

  15. Moment approach to tandem mirror radial transport

    International Nuclear Information System (INIS)

    Siebert, K.D.; Callen, J.D.

    1986-02-01

    A moment approach is proposed for the study of tandem mirror radial transport in the resonant plateau regime. The salient features of the method are described with reference to axisymmetric tokamak transport theory. In particular, the importance of momentum conservation to the establishment of the azimuthal variations in the electrostatic potential is demonstrated. Also, an ad hoc drift kinetic equation is solved to determine parallel viscosity coefficients which are required to close the moment system

  16. Numerical simulation of radial compressor stage

    Science.gov (United States)

    Syka, T.; Luňáček, O.

    2013-04-01

    Article describes numerical simulations of air flow in radial compressor stage in NUMECA CFD software. In simulations geometry variants with and without seals are used. During tasks evaluating was observed seals influence on flow field and performance parameters of compressor stage. Also is described CFDresults comparison with results from design software based on experimental measurements and monitoring of influence of seals construction on compressor stage efficiency.

  17. Numerical simulation of radial compressor stage

    OpenAIRE

    Luňáček O.; Syka T.

    2013-01-01

    Article describes numerical simulations of air flow in radial compressor stage in NUMECA CFD software. In simulations geometry variants with and without seals are used. During tasks evaluating was observed seals influence on flow field and performance parameters of compressor stage. Also is described CFDresults comparison with results from design software based on experimental measurements and monitoring of influence of seals construction on compressor stage efficiency.

  18. Numerical simulation of radial compressor stage

    Directory of Open Access Journals (Sweden)

    Luňáček O.

    2013-04-01

    Full Text Available Article describes numerical simulations of air flow in radial compressor stage in NUMECA CFD software. In simulations geometry variants with and without seals are used. During tasks evaluating was observed seals influence on flow field and performance parameters of compressor stage. Also is described CFDresults comparison with results from design software based on experimental measurements and monitoring of influence of seals construction on compressor stage efficiency.

  19. Radial excitations in nucleon-nucleon scattering

    International Nuclear Information System (INIS)

    Silvestre-Brac, B.; Carbonell, J.; Gignoux, C.

    1986-01-01

    In the non-relativistic constituent quark model, the role of the radial excitations of the nucleon is studied within a resonating group approach of the nucleon-nucleon scattering. It is shown that, rather than the inclusion of new channels, it is important to include mixed-symmetry spin-isospin components in the nucleon wave function. It is also found that during the collision there is no significant deformation of the nucleon. (orig.)

  20. Learning Methods for Radial Basis Functions Networks

    Czech Academy of Sciences Publication Activity Database

    Neruda, Roman; Kudová, Petra

    2005-01-01

    Roč. 21, - (2005), s. 1131-1142 ISSN 0167-739X R&D Projects: GA ČR GP201/03/P163; GA ČR GA201/02/0428 Institutional research plan: CEZ:AV0Z10300504 Keywords : radial basis function networks * hybrid supervised learning * genetic algorithms * benchmarking Subject RIV: BA - General Mathematics Impact factor: 0.555, year: 2005

  1. Reactivity on the Web

    OpenAIRE

    Bailey, James; Bry, François; Eckert, Michael; Patrânjan, Paula Lavinia

    2005-01-01

    Reactivity, the ability to detect simple and composite events and respond in a timely manner, is an essential requirement in many present-day information systems. With the emergence of new, dynamic Web applications, reactivity on the Web is receiving increasing attention. Reactive Web-based systems need to detect and react not only to simple events but also to complex, real-life situations. This paper introduces XChange, a language for programming reactive behaviour on the Web,...

  2. Fast radial basis functions for engineering applications

    CERN Document Server

    Biancolini, Marco Evangelos

    2017-01-01

    This book presents the first “How To” guide to the use of radial basis functions (RBF). It provides a clear vision of their potential, an overview of ready-for-use computational tools and precise guidelines to implement new engineering applications of RBF. Radial basis functions (RBF) are a mathematical tool mature enough for useful engineering applications. Their mathematical foundation is well established and the tool has proven to be effective in many fields, as the mathematical framework can be adapted in several ways. A candidate application can be faced considering the features of RBF:  multidimensional space (including 2D and 3D), numerous radial functions available, global and compact support, interpolation/regression. This great flexibility makes RBF attractive – and their great potential has only been partially discovered. This is because of the difficulty in taking a first step toward RBF as they are not commonly part of engineers’ cultural background, but also due to the numerical complex...

  3. Fuel radial design using Path Relinking

    International Nuclear Information System (INIS)

    Campos S, Y.

    2007-01-01

    The present work shows the obtained results when implementing the combinatory optimization technique well-known as Path Re linking (Re-linkage of Trajectories), to the problem of the radial design of nuclear fuel assemblies, for boiling water reactors (BWR Boiling Water Reactor by its initials in English), this type of reactors is those that are used in the Laguna Verde Nucleo electric Central, Veracruz. As in any other electric power generation plant of that make use of some fuel to produce heat and that it needs each certain time (from 12 to 14 months) to make a supply of the same one, because this it wears away or it burns, in the nucleolectric plants to this activity is denominated fuel reload. In this reload different activities intervene, among those which its highlight the radial and axial designs of fuel assemblies, the patterns of control rods and the multi cycles study, each one of these stages with their own complexity. This work was limited to study in independent form the radial design, without considering the other activities. These phases are basic for the fuel reload design and of reactor operation strategies. (Author)

  4. Development of a Radial Deconsolidation Method

    Energy Technology Data Exchange (ETDEWEB)

    Helmreich, Grant W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Montgomery, Fred C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hunn, John D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-01

    A series of experiments have been initiated to determine the retention or mobility of fission products* in AGR fuel compacts [Petti, et al. 2010]. This information is needed to refine fission product transport models. The AGR-3/4 irradiation test involved half-inch-long compacts that each contained twenty designed-to-fail (DTF) particles, with 20-μm thick carbon-coated kernels whose coatings were deliberately fabricated such that they would crack under irradiation, providing a known source of post-irradiation isotopes. The DTF particles in these compacts were axially distributed along the compact centerline so that the diffusion of fission products released from the DTF kernels would be radially symmetric [Hunn, et al. 2012; Hunn et al. 2011; Kercher, et al. 2011; Hunn, et al. 2007]. Compacts containing DTF particles were irradiated at Idaho National Laboratory (INL) at the Advanced Test Reactor (ATR) [Collin, 2015]. Analysis of the diffusion of these various post-irradiation isotopes through the compact requires a method to radially deconsolidate the compacts so that nested-annular volumes may be analyzed for post-irradiation isotope inventory in the compact matrix, TRISO outer pyrolytic carbon (OPyC), and DTF kernels. An effective radial deconsolidation method and apparatus appropriate to this application has been developed and parametrically characterized.

  5. Thermal expansion of beryllium oxide

    International Nuclear Information System (INIS)

    Solodukhin, A.V.; Kruzhalov, A.V.; Mazurenko, V.G.; Maslov, V.A.; Medvedev, V.A.; Polupanova, T.I.

    1987-01-01

    Precise measurements of temperature dependence of the coefficient of linear expansion in the 22-320 K temperature range on beryllium oxide monocrystals are conducted. A model of thermal expansion is suggested; the range of temperature dependence minimum of the coefficient of thermal expansion is well described within the frames of this model. The results of the experiment may be used for investigation of thermal stresses in crystals

  6. Monadic Functional Reactive Programming

    NARCIS (Netherlands)

    A.J. van der Ploeg (Atze); C Shan

    2013-01-01

    htmlabstractFunctional Reactive Programming (FRP) is a way to program reactive systems in functional style, eliminating many of the problems that arise from imperative techniques. In this paper, we present an alternative FRP formulation that is based on the notion of a reactive computation: a

  7. Comment on "A note on generalized radial mesh generation for plasma electronic structure"

    Science.gov (United States)

    Pain, J.-Ch.

    2011-12-01

    In a recent note, B.G. Wilson and V. Sonnad [1] proposed a very useful closed form expression for the efficient generation of analytic log-linear radial meshes. The central point of the note is an implicit equation for the parameter h, involving Lambert's function W[x]. The authors mention that they are unaware of any direct proof of this equation (they obtained it by re-summing the Taylor expansion of h[α] using high-order coefficients obtained by analytic differentiation of the implicit definition using symbolic manipulation). In the present comment, we propose a direct proof of that equation.

  8. Coupling-parameter expansion in thermodynamic perturbation theory.

    Science.gov (United States)

    Ramana, A Sai Venkata; Menon, S V G

    2013-02-01

    An approach to the coupling-parameter expansion in the liquid state theory of simple fluids is presented by combining the ideas of thermodynamic perturbation theory and integral equation theories. This hybrid scheme avoids the problems of the latter in the two phase region. A method to compute the perturbation series to any arbitrary order is developed and applied to square well fluids. Apart from the Helmholtz free energy, the method also gives the radial distribution function and the direct correlation function of the perturbed system. The theory is applied for square well fluids of variable ranges and compared with simulation data. While the convergence of perturbation series and the overall performance of the theory is good, improvements are needed for potentials with shorter ranges. Possible directions for further developments in the coupling-parameter expansion are indicated.

  9. Adiabatic Expansion of Electron Gas in a Magnetic Nozzle

    Science.gov (United States)

    Takahashi, Kazunori; Charles, Christine; Boswell, Rod; Ando, Akira

    2018-01-01

    A specially constructed experiment shows the near perfect adiabatic expansion of an ideal electron gas resulting in a polytropic index greater than 1.4, approaching the adiabatic value of 5 /3 , when removing electric fields from the system, while the polytropic index close to unity is observed when the electrons are trapped by the electric fields. The measurements were made on collisionless electrons in an argon plasma expanding in a magnetic nozzle. The collision lengths of all electron collision processes are greater than the scale length of the expansion, meaning the system cannot be in thermodynamic equilibrium, yet thermodynamic concepts can be used, with caution, in explaining the results. In particular, a Lorentz force, created by inhomogeneities in the radial plasma density, does work on the expanding magnetic field, reducing the internal energy of the electron gas that behaves as an adiabatically expanding ideal gas.

  10. Linear theory radial and nonradial pulsations of DA dwarf stars

    International Nuclear Information System (INIS)

    Starrfield, S.; Cox, A.N.; Hodson, S.; Pesnell, W.D.

    1982-01-01

    The Los Alamos stellar envelope and radial linear non-adiabatic computer code, along with a new Los Alamos non-radial code are used to investigate the total hydrogen mass necessary to produce the non-radial instability of DA dwarfs

  11. Radial distribution of ions in pores with a surface charge

    NARCIS (Netherlands)

    Stegen, J.H.G. van der; Görtzen, J.; Kuipers, J.A.M.; Hogendoorn, J.A.; Versteeg, G.F.

    2001-01-01

    A sorption model applicable to calculate the radial equilibrium concentrations of ions in the pores of ion-selective membranes with a pore structure is developed. The model is called the radial uptake model. Because the model is applied to a Nafion sulfonic layer with very small pores and the radial

  12. Evaluation of the radial design of fuel cells in an operation cycle of a BWR reactor

    International Nuclear Information System (INIS)

    Gonzalez C, J.; Martin del Campo M, C.

    2003-01-01

    This work is continuation of one previous in the one that the application of the optimization technique called Tabu search to the radial design of fuel cells of boiling water reactors (BWR, Boiling Water Reactor) is presented. The objective function used in the optimization process only include neutron parameters (k-infinite and peak of radial power) considering the cell at infinite media. It was obtained to reduce the cell average enrichment completing the characteristics of reactivity of an original cell. The objective of the present work is to validate the objective function that was used for the radial design of the fuel cell (test cell), analyzing the operation of a one cycle of the reactor in which fuels have been fresh recharged that contain an axial area with the nuclear database of the cell designed instead of the original cell. For it is simulated it with Cm-Presto the cycle 10 of the reactor operation of the Unit 1 of the Nuclear Power station of Laguna Verde (U1-CNLV). For the cycle evaluation its were applied so much the simulation with the Haling strategy, as the simulation of the one cycle with control rod patterns and they were evaluated the energy generation and several power limits and reactivity that are used as design parameters in fuel reloads of BWR reactors. The results at level of an operation cycle of the reactor, show that the objective function used in the optimization and radial design of the cell is adequate and that it can induce to one good use of the fuel. (Author)

  13. Digital reactivity meter

    International Nuclear Information System (INIS)

    Akkus, B.; Anac, H.; Alsan, S.; Erk, S.

    1991-01-01

    Nowadays, various digital methods making use of microcomputers for neutron detector signals and determining the reactivity by numerical calculations are used in reactor control systems in place of classical reactivity meters. In this work, a calculation based on the ''The Time Dependent Transport Equation'' has been developed for determining the reactivity numerically. The reactivity values have been obtained utilizing a computer-based data acquisition and control system and compared with the analog reactivity meter values as well as the values calculated from the ''Inhour Equation''

  14. A radial velocity survey of the Carina Nebula's O-type stars

    Science.gov (United States)

    Kiminki, Megan M.; Smith, Nathan

    2018-03-01

    We have obtained multi-epoch observations of 31 O-type stars in the Carina Nebula using the CHIRON spectrograph on the CTIO/SMARTS 1.5-m telescope. We measure their radial velocities to 1-2 km s-1 precision and present new or updated orbital solutions for the binary systems HD 92607, HD 93576, HDE 303312, and HDE 305536. We also compile radial velocities from the literature for 32 additional O-type and evolved massive stars in the region. The combined data set shows a mean heliocentric radial velocity of 0.6 km s-1. We calculate a velocity dispersion of ≤9.1 km s-1, consistent with an unbound, substructured OB association. The Tr 14 cluster shows a marginally significant 5 km s-1 radial velocity offset from its neighbor Tr 16, but there are otherwise no correlations between stellar position and velocity. The O-type stars in Cr 228 and the South Pillars region have a lower velocity dispersion than the region as a whole, supporting a model of distributed massive-star formation rather than migration from the central clusters. We compare our stellar velocities to the Carina Nebula's molecular gas and find that Tr 14 shows a close kinematic association with the Northern Cloud. In contrast, Tr 16 has accelerated the Southern Cloud by 10-15 km s-1, possibly triggering further massive-star formation. The expansion of the surrounding H II region is not symmetric about the O-type stars in radial velocity space, indicating that the ionized gas is constrained by denser material on the far side.

  15. A radial velocity survey of the Carina Nebula's O-type stars

    Science.gov (United States)

    Kiminki, Megan M.; Smith, Nathan

    2018-06-01

    We have obtained multi-epoch observations of 31 O-type stars in the Carina Nebula using the CHIRON spectrograph on the CTIO/SMARTS 1.5-m telescope. We measure their radial velocities to 1-2 km s-1 precision and present new or updated orbital solutions for the binary systems HD 92607, HD 93576, HDE 303312, and HDE 305536. We also compile radial velocities from the literature for 32 additional O-type and evolved massive stars in the region. The combined data set shows a mean heliocentric radial velocity of 0.6 km s-1. We calculate a velocity dispersion of ≤9.1 km s-1, consistent with an unbound, substructured OB association. The Tr 14 cluster shows a marginally significant 5 km s-1 radial velocity offset from its neighbour Tr 16, but there are otherwise no correlations between stellar position and velocity. The O-type stars in Cr 228 and the South Pillars region have a lower velocity dispersion than the region as a whole, supporting a model of distributed massive star formation rather than migration from the central clusters. We compare our stellar velocities to the Carina Nebula's molecular gas and find that Tr 14 shows a close kinematic association with the Northern Cloud. In contrast, Tr 16 has accelerated the Southern Cloud by 10-15 km s-1, possibly triggering further massive star formation. The expansion of the surrounding H II region is not symmetric about the O-type stars in radial velocity space, indicating that the ionized gas is constrained by denser material on the far side.

  16. Experimental feasibility study of radial injection cooling of three-pad radial air foil bearings

    Science.gov (United States)

    Shrestha, Suman K.

    Air foil bearings use ambient air as a lubricant allowing environment-friendly operation. When they are designed, installed, and operated properly, air foil bearings are very cost effective and reliable solution to oil-free turbomachinery. Because air is used as a lubricant, there are no mechanical contacts between the rotor and bearings and when the rotor is lifted off the bearing, near frictionless quiet operation is possible. However, due to the high speed operation, thermal management is one of the very important design factors to consider. Most widely accepted practice of the cooling method is axial cooling, which uses cooling air passing through heat exchange channels formed underneath the bearing pad. Advantage is no hardware modification to implement the axial cooling because elastic foundation structure of foil bearing serves as a heat exchange channels. Disadvantage is axial temperature gradient on the journal shaft and bearing. This work presents the experimental feasibility study of alternative cooling method using radial injection of cooling air directly on the rotor shaft. The injection speeds, number of nozzles, location of nozzles, total air flow rate are important factors determining the effectiveness of the radial injection cooling method. Effectiveness of the radial injection cooling was compared with traditional axial cooling method. A previously constructed test rig was modified to accommodate a new motor with higher torque and radial injection cooling. The radial injection cooling utilizes the direct air injection to the inlet region of air film from three locations at 120° from one another with each location having three axially separated holes. In axial cooling, a certain axial pressure gradient is applied across the bearing to induce axial cooling air through bump foil channels. For the comparison of the two methods, the same amount of cooling air flow rate was used for both axial cooling and radial injection. Cooling air flow rate was

  17. Method of controlling reactivity

    International Nuclear Information System (INIS)

    Tochihara, Hiroshi.

    1982-01-01

    Purpose: To improve the reactivity controlling characteristics by artificially controlling the leakage of neutron from a reactor and providing a controller for controlling the reactivity. Method: A reactor core is divided into several water gaps to increase the leakage of neutron, its reactivity is reduced, a gas-filled control rod or a fuel assembly is inserted into the gap as required, the entire core is coupled in a system to reduce the leakage of the neutron, and the reactivity is increased. The reactor shutdown is conducted by the conventional control rod, and to maintain critical state, boron density varying system is used together. Futher, a control rod drive is used with that similar to the conventional one, thereby enabling fast reactivity variation, and the positive reactivity can be obtained by the insertion, thereby improving the reactivity controlling characteristics. (Yoshihara, H.)

  18. Renormalization group and Mayer expansions

    International Nuclear Information System (INIS)

    Mack, G.

    1984-02-01

    Mayer expansions promise to become a powerful tool in exact renormalization group calculations. Iterated Mayer expansions were sucessfully used in the rigorous analysis of 3-dimensional U(1) lattice gauge theory by Goepfert and the author, and it is hoped that they will also be useful in the 2-dimensional nonlinear sigma-model, and elsewhere. (orig.)

  19. Isotropic Negative Thermal Expansion Metamaterials.

    Science.gov (United States)

    Wu, Lingling; Li, Bo; Zhou, Ji

    2016-07-13

    Negative thermal expansion materials are important and desirable in science and engineering applications. However, natural materials with isotropic negative thermal expansion are rare and usually unsatisfied in performance. Here, we propose a novel method to achieve two- and three-dimensional negative thermal expansion metamaterials via antichiral structures. The two-dimensional metamaterial is constructed with unit cells that combine bimaterial strips and antichiral structures, while the three-dimensional metamaterial is fabricated by a multimaterial 3D printing process. Both experimental and simulation results display isotropic negative thermal expansion property of the samples. The effective coefficient of negative thermal expansion of the proposed models is demonstrated to be dependent on the difference between the thermal expansion coefficient of the component materials, as well as on the circular node radius and the ligament length in the antichiral structures. The measured value of the linear negative thermal expansion coefficient of the three-dimensional sample is among the largest achieved in experiments to date. Our findings provide an easy and practical approach to obtaining materials with tunable negative thermal expansion on any scale.

  20. Renormalization group and mayer expansions

    International Nuclear Information System (INIS)

    Mack, G.

    1984-01-01

    Mayer expansions promise to become a powerful tool in exact renormalization group calculations. Iterated Mayer expansions were sucessfully used in the rigorous analysis of 3-dimensional U (1) lattice gauge theory by Gopfert and the author, and it is hoped that they will also be useful in the 2-dimensional nonlinear σ-model, and elsewhere

  1. On summation of perturbation expansions

    International Nuclear Information System (INIS)

    Horzela, A.

    1985-04-01

    The problem of the restoration of physical quantities defined by divergent perturbation expansions is analysed. The Pad'e and Borel summability is proved for alternating perturbation expansions with factorially growing coefficients. The proof is based on the methods of the classical moments theory. 17 refs. (author)

  2. Operating cost minimization of a radial distribution system in a deregulated electricity market through reconfiguration using NSGA method

    International Nuclear Information System (INIS)

    Chandramohan, S.; Atturulu, Naresh; Devi, R.P. Kumudini; Venkatesh, B.

    2010-01-01

    In the future, mechanisms for trade in ancillary services such as reactive power will be implemented in many deregulated power systems. In such an operating framework, a Distribution Corporation (DisCo) would have to purchase reactive power along with real power from the connected transmission corporation. A DisCo would want to minimize its operating costs by minimizing the total amount of real and reactive power drawn from the connected transmission system. Optimally reconfiguring the network will achieve such a goal. In this work, we use a non-dominated sorting genetic algorithm (NSGA) for reconfiguring a radial DisCo to minimize its operating costs considering real and reactive power costs while maximizing its operating reliability and satisfying the regular operating constraints. This method is tested on sample test systems and reported. (author)

  3. Methods and apparatus for radially compliant component mounting

    Science.gov (United States)

    Bulman, David Edward [Cincinnati, OH; Darkins, Jr., Toby George; Stumpf, James Anthony [Columbus, IN; Schroder, Mark S [Greenville, SC; Lipinski, John Joseph [Simpsonville, SC

    2012-03-27

    Methods and apparatus for a mounting assembly for a liner of a gas turbine engine combustor are provided. The combustor includes a combustor liner and a radially outer annular flow sleeve. The mounting assembly includes an inner ring surrounding a radially outer surface of the liner and including a plurality of axially extending fingers. The mounting assembly also includes a radially outer ring coupled to the inner ring through a plurality of spacers that extend radially from a radially outer surface of the inner ring to the outer ring.

  4. RADIALLY MAGNETIZED PROTOPLANETARY DISK: VERTICAL PROFILE

    International Nuclear Information System (INIS)

    Russo, Matthew; Thompson, Christopher

    2015-01-01

    This paper studies the response of a thin accretion disk to an external radial magnetic field. Our focus is on protoplanetary disks (PPDs), which are exposed during their later evolution to an intense, magnetized wind from the central star. A radial magnetic field is mixed into a thin surface layer, wound up by the disk shear, and pushed downward by a combination of turbulent mixing and ambipolar and ohmic drift. The toroidal field reaches much greater strengths than the seed vertical field that is usually invoked in PPD models, even becoming superthermal. Linear stability analysis indicates that the disk experiences the magnetorotational instability (MRI) at a higher magnetization than a vertically magnetized disk when both the effects of ambipolar and Hall drift are taken into account. Steady vertical profiles of density and magnetic field are obtained at several radii between 0.06 and 1 AU in response to a wind magnetic field B r ∼ (10 −4 –10 −2 )(r/ AU) −2 G. Careful attention is given to the radial and vertical ionization structure resulting from irradiation by stellar X-rays. The disk is more strongly magnetized closer to the star, where it can support a higher rate of mass transfer. As a result, the inner ∼1 AU of a PPD is found to evolve toward lower surface density. Mass transfer rates around 10 −8 M ⊙ yr −1 are obtained under conservative assumptions about the MRI-generated stress. The evolution of the disk and the implications for planet migration are investigated in the accompanying paper

  5. RADIALLY MAGNETIZED PROTOPLANETARY DISK: VERTICAL PROFILE

    Energy Technology Data Exchange (ETDEWEB)

    Russo, Matthew [Department of Physics, University of Toronto, 60 St. George St., Toronto, ON M5S 1A7 (Canada); Thompson, Christopher [Canadian Institute for Theoretical Astrophysics, 60 St. George St., Toronto, ON M5S 3H8 (Canada)

    2015-11-10

    This paper studies the response of a thin accretion disk to an external radial magnetic field. Our focus is on protoplanetary disks (PPDs), which are exposed during their later evolution to an intense, magnetized wind from the central star. A radial magnetic field is mixed into a thin surface layer, wound up by the disk shear, and pushed downward by a combination of turbulent mixing and ambipolar and ohmic drift. The toroidal field reaches much greater strengths than the seed vertical field that is usually invoked in PPD models, even becoming superthermal. Linear stability analysis indicates that the disk experiences the magnetorotational instability (MRI) at a higher magnetization than a vertically magnetized disk when both the effects of ambipolar and Hall drift are taken into account. Steady vertical profiles of density and magnetic field are obtained at several radii between 0.06 and 1 AU in response to a wind magnetic field B{sub r} ∼ (10{sup −4}–10{sup −2})(r/ AU){sup −2} G. Careful attention is given to the radial and vertical ionization structure resulting from irradiation by stellar X-rays. The disk is more strongly magnetized closer to the star, where it can support a higher rate of mass transfer. As a result, the inner ∼1 AU of a PPD is found to evolve toward lower surface density. Mass transfer rates around 10{sup −8} M{sub ⊙} yr{sup −1} are obtained under conservative assumptions about the MRI-generated stress. The evolution of the disk and the implications for planet migration are investigated in the accompanying paper.

  6. Radial fractional Laplace operators and Hessian inequalities

    Science.gov (United States)

    Ferrari, Fausto; Verbitsky, Igor E.

    In this paper we deduce a formula for the fractional Laplace operator ( on radially symmetric functions useful for some applications. We give a criterion of subharmonicity associated with (, and apply it to a problem related to the Hessian inequality of Sobolev type: ∫Rn |(u| dx⩽C∫Rn -uFk[u] dx, where Fk is the k-Hessian operator on Rn, 1⩽kFerrari et al. [5] contains the extremal functions for the Hessian Sobolev inequality of X.-J. Wang (1994) [15]. This is proved using logarithmic convexity of the Gaussian ratio of hypergeometric functions which might be of independent interest.

  7. Convex and Radially Concave Contoured Distributions

    Directory of Open Access Journals (Sweden)

    Wolf-Dieter Richter

    2015-01-01

    Full Text Available Integral representations of the locally defined star-generalized surface content measures on star spheres are derived for boundary spheres of balls being convex or radially concave with respect to a fan in Rn. As a result, the general geometric measure representation of star-shaped probability distributions and the general stochastic representation of the corresponding random vectors allow additional specific interpretations in the two mentioned cases. Applications to estimating and testing hypotheses on scaling parameters are presented, and two-dimensional sample clouds are simulated.

  8. On radial flow between parallel disks

    International Nuclear Information System (INIS)

    Wee, A Y L; Gorin, A

    2015-01-01

    Approximate analytical solutions are presented for converging flow in between two parallel non rotating disks. The static pressure distribution and radial component of the velocity are developed by averaging the inertial term across the gap in between parallel disks. The predicted results from the first approximation are favourable to experimental results as well as results presented by other authors. The second approximation shows that as the fluid approaches the center, the velocity at the mid channel slows down which is due to the struggle between the inertial term and the flowrate. (paper)

  9. Intraluminal milrinone for dilation of the radial artery graft.

    Science.gov (United States)

    García-Rinaldi, R; Soltero, E R; Carballido, J; Mojica, J

    1999-01-01

    There is renewed interest in the use of the radial artery as a conduit for coronary artery bypass surgery. The radial artery is, however, a very muscular artery, prone to vasospasm. Milrinone, a potent vasodilator, has demonstrated vasodilatory properties superior to those of papaverine. In this report, we describe our technique of radial artery harvesting and the adjunctive use of intraluminal milrinone as a vasodilator in the preparation of this conduit for coronary artery bypass grafting. We have used these techniques in 25 patients who have undergone coronary artery bypass grafting using the radial artery. No hand ischemic complications have been observed in this group. Intraluminal milrinone appears to dilate and relax the radial artery, rendering this large conduit spasm free and very easy to use. We recommend the skeletonization technique for radial artery harvesting and the use of intraluminal milrinone as a radial artery vasodilator in routine myocardial revascularization. PMID:10524740

  10. Control Rod Driveline Reactivity Feedback Model for Liquid Metal Reactors

    International Nuclear Information System (INIS)

    Kwon, Young-Min; Jeong, Hae-Yong; Chang, Won-Pyo; Cho, Chung-Ho; Lee, Yong-Bum

    2008-01-01

    The thermal expansion of the control rod drivelines (CRDL) is one important passive mitigator under all unprotected accident conditions in the metal and oxide cores. When the CRDL are washed by hot sodium in the coolant outlet plenum, the CRDL thermally expands and causes the control rods to be inserted further down into the active core region, providing a negative reactivity feedback. Since the control rods are attached to the top of the vessel head and the core attaches to the bottom of the reactor vessel (RV), the expansion of the vessel wall as it heats will either lower the core or raise the control rods supports. This contrary thermal expansion of the reactor vessel wall pulls the control rods out of the core somewhat, providing a positive reactivity feedback. However this is not a safety factor early in a transient because its time constant is relatively large. The total elongated length is calculated by subtracting the vessel expansion from the CRDL expansion to determine the net control rod expansion into the core. The system-wide safety analysis code SSC-K includes the CRDL/RV reactivity feedback model in which control rod and vessel expansions are calculated using single-nod temperatures for the vessel and CRDL masses. The KALIMER design has the upper internal structures (UIS) in which the CRDLs are positioned outside the structure where they are exposed to the mixed sodium temperature exiting the core. A new method to determine the CRDL expansion is suggested. Two dimensional hot pool thermal hydraulic model (HP2D) originally developed for the analysis of the stratification phenomena in the hot pool is utilized for a detailed heat transfer between the CRDL mass and the hot pool coolant. However, the reactor vessel wall temperature is still calculated by a simple lumped model

  11. Spherical radial basis functions, theory and applications

    CERN Document Server

    Hubbert, Simon; Morton, Tanya M

    2015-01-01

    This book is the first to be devoted to the theory and applications of spherical (radial) basis functions (SBFs), which is rapidly emerging as one of the most promising techniques for solving problems where approximations are needed on the surface of a sphere. The aim of the book is to provide enough theoretical and practical details for the reader to be able to implement the SBF methods to solve real world problems. The authors stress the close connection between the theory of SBFs and that of the more well-known family of radial basis functions (RBFs), which are well-established tools for solving approximation theory problems on more general domains. The unique solvability of the SBF interpolation method for data fitting problems is established and an in-depth investigation of its accuracy is provided. Two chapters are devoted to partial differential equations (PDEs). One deals with the practical implementation of an SBF-based solution to an elliptic PDE and another which describes an SBF approach for solvi...

  12. Asymptotic Solutions of Serial Radial Fuel Shuffling

    Directory of Open Access Journals (Sweden)

    Xue-Nong Chen

    2015-12-01

    Full Text Available In this paper, the mechanism of traveling wave reactors (TWRs is investigated from the mathematical physics point of view, in which a stationary fission wave is formed by radial fuel drifting. A two dimensional cylindrically symmetric core is considered and the fuel is assumed to drift radially according to a continuous fuel shuffling scheme. A one-group diffusion equation with burn-up dependent macroscopic coefficients is set up. The burn-up dependent macroscopic coefficients were assumed to be known as functions of neutron fluence. By introducing the effective multiplication factor keff, a nonlinear eigenvalue problem is formulated. The 1-D stationary cylindrical coordinate problem can be solved successively by analytical and numerical integrations for associated eigenvalues keff. Two representative 1-D examples are shown for inward and outward fuel drifting motions, respectively. The inward fuel drifting has a higher keff than the outward one. The 2-D eigenvalue problem has to be solved by a more complicated method, namely a pseudo time stepping iteration scheme. Its 2-D asymptotic solutions are obtained together with certain eigenvalues keff for several fuel inward drifting speeds. Distributions of the neutron flux, the neutron fluence, the infinity multiplication factor kinf and the normalized power are presented for two different drifting speeds.

  13. [Comparison of chemical quality characteristics between radial striations and non-radial striations in tuberous root of Rehmannia glutinosa].

    Science.gov (United States)

    Xie, Cai-Xia; Zhang, Miao; Li, Ya-Jing; Geng, Xiao-Tong; Wang, Feng-Qing; Zhang, Zhong-Yi

    2017-11-01

    An HPLC method was established to determine the contents of catalpol, acteoside, rehmaionoside A, rehmaionoside D, leonuride in three part of Rehmanni glutinosa in Beijing No.1 variety R. glutinosa during the growth period, This method, in combination with its HPLC fingerprint was used to evaluate its overall quality characteristics.The results showed that:① the content of main components of R. glutinosa varied in different growth stages ;② there was a great difference of the content of main components between theradial striations and the non-radial striations; ③ the two sections almost have the same content distribution of catalpol, acteoside and rehmaionoside D; ④the content of rehmaionoside A in non-radial striations was higher than that in radial striations,while the content of leonuride in radial striations was higher than that in non-radial striations.; ⑤the HPLC fingerprint of radial striations, non-radial striations and whole root tuber were basically identical, except for the big difference in the content of chemical components. The result of clustering displayed that the radial striations, non-radial striations, and whole root were divided into two groups. In conclusion, there was a significant difference in the quality characteristics of radial striations and non-radial striations of R. glutinosa. This research provides a reference for quality evaluation and geoherbalism of R. glutinosa. Copyright© by the Chinese Pharmaceutical Association.

  14. Reactive Programming in Java

    CERN Document Server

    CERN. Geneva

    2017-01-01

    Reactive Programming in gaining a lot of excitement. Many libraries, tools, and frameworks are beginning to make use of reactive libraries. Besides, applications dealing with big data or high frequency data can benefit from this programming paradigm. Come to this presentation to learn about what reactive programming is, what kind of problems it solves, how it solves them. We will take an example oriented approach to learning the programming model and the abstraction.

  15. An axially and radially two-zoned large liquid-metal fast breeder reactor core concept

    International Nuclear Information System (INIS)

    Kamei, T.; Arie, K.; Moriki, Y.; Suzuki, M.; Yamaoka, M.

    1985-01-01

    A new core concept that has advantages over conventional homogeneous cores in neutronics characteristics such as power peaking factor, burnup reactivity loss, and reactivity response to the movement of control rods in earthquakes has been evolved. Two options of the new core concept are feasible. One is the so-called axially heterogeneous core, with the internal blanket placed at the lower part of the core. The other concept is similar to the conventional homogeneous core, but has two different plutonium-enriched zones in the axial as well as in the radial direction, so it is a hybrid type of the conventional homogeneous core and the axially heterogeneous core. The new design concept is described and the way that the core characteristics are improved by the chosen key parameters is shown

  16. A technique for computing bowing reactivity feedback in LMFBR's

    International Nuclear Information System (INIS)

    Finck, P.J.

    1987-01-01

    During normal or accidental transients occurring in a LMFBR core, the assemblies and their support structure are subjected to important thermal gradients which induce differential thermal expansions of the walls of the hexcans and differential displacement of the assembly support structure. These displacements, combined with the creep and swelling of structural materials, remain quite small, but the resulting reactivity changes constitute a significant component of the reactivity feedback coefficients used in safety analyses. It would be prohibitive to compute the reactivity changes due to all transients. Thus, the usual practice is to generate reactivity gradient tables. The purpose of the work presented here is twofold: develop and validate an efficient and accurate scheme for computing these reactivity tables; and to qualify this scheme

  17. BN600 reactivity definition

    International Nuclear Information System (INIS)

    Zheltyshev, V.; Ivanov, A.

    2000-01-01

    Since 1980, the fast BN600 reactor with sodium coolant has been operated at Beloyarsk Nuclear Power Plant. The periodic monitoring of the reactivity modifications should be implemented in compliance with the standards and regulations applied in nuclear power engineering. The reactivity measurements are carried out in order to confirm the basic neutronic features of a BN600 reactor. The reactivity measurements are aimed to justify that nuclear safety is provided in course of the in-reactor installation of the experimental core components. Two reactivity meters are to be used on BN600 operation: 1. Digital on-line reactivity calculated under stationary reactor operation on power (approximation of the point-wise kinetics is applied). 2. Second reactivity meter used to define the reactor control rod operating components efficiency under reactor startup and take account of the changing efficiency of the sensor, however, this is more time-consumptive than the on-line reactivity meter. The application of two reactivity meters allows for the monitoring of the reactor reactivity under every operating mode. (authors)

  18. Plasma expansion: fundamentals and applications

    International Nuclear Information System (INIS)

    Engeln, R; Mazouffre, S; Vankan, P; Bakker, I; Schram, D C

    2002-01-01

    The study of plasma expansion is interesting from a fundamental point of view as well as from a more applied point of view. We here give a short overview of the way properties like density, velocity and temperature behave in an expanding thermal plasma. Experimental data show that the basic phenomena of plasma expansion are to some extent similar to those of the expansion of a hot neutral gas. From the application point of view, we present first results on the use of an expanding thermal plasma in the plasma-activated catalysis of ammonia, from N 2 -H 2 mixtures

  19. A possible case of radially antisunward propagating substorm onset in the near-earth magnetotail

    International Nuclear Information System (INIS)

    Lopez, R.E.; McEntire, R.W.; Potemra, T.A.

    1990-01-01

    It is generally thought that the local effects associated with substorm onset in the near-Earth magnetotail (R '' E ) have a component of propagation which is radially earthward. This study presents a case during which it is possible that the local effects of substorm onset propagated radially antisunward. We examine energetic ion and magnetic field data and energetic particle data from the geosynchronous satellite 1982-019 during a period of weak substorm activity on 11 June 1985. Although the effects of this event on the ground were very weak, the substorm had a dramatic effect on at least one portion of the near-Earth magnetotail. During the period of interest the spacecraft were in an unusually close radial alignment. The data show that phenomena which we associate with the local effects of substorm onset began at or near geosynchronous before they were observed at the station (R = 8.8R E ). We believe that this event is best explained by a near-Earth disruption of the cross-tail current sheet and the consequent formation of a substorm current wedge, and that this process had a component of expansion antisunward down the tail. (author)

  20. A new trapped-ion instability with large frequency and radial wavenumber

    International Nuclear Information System (INIS)

    Tagger, M.

    1979-01-01

    The need for theoretical previsions concerning anomalous transport in large Tokamaks, as well as the recent results of PLT, ask the question of the process responsible for non-linear saturation of trapped-ion instabilities. This in turn necessitates the knowledge of the linear behaviour of these waves at large frequencies and large radial wavenumbers. We study the linear dispersion relation of these modes, in the radially local approximation, but including a term due to a new physical effect, combining finite banana-width and bounce resonances. Limiting ourselves presently to the first harmonic expansion of the bounce motion of trapped ions, we show that the effect of finite banana-width on the usual trapped-ion mode is complex and quite different from what is generally expected. In addition we show, analytically and numerically, the appearance of a nex branch of this instability. Essentially due to this new effect, it involves large frequencies (ω approximately ωsub(b) and is destabilized by large radial wavelengths (ksub(x) Λ approximately 1, where Λ is the typical banana-width). We discuss the nature of this new mode and its potential relevance of the experiments

  1. Exploring the conformational and reactive dynamics of biomolecules in solution using an extended version of the glycine reactive force field

    DEFF Research Database (Denmark)

    Monti, Susanna; Corozzi, Alessandro; Fristrup, Peter

    2013-01-01

    In order to describe possible reaction mechanisms involving amino acids, and the evolution of the protonation state of amino acid side chains in solution, a reactive force field (ReaxFF-based description) for peptide and protein simulations has been developed as an expansion of the previously rep...

  2. Computer model analysis of the radial artery pressure waveform.

    Science.gov (United States)

    Schwid, H A; Taylor, L A; Smith, N T

    1987-10-01

    Simultaneous measurements of aortic and radial artery pressures are reviewed, and a model of the cardiovascular system is presented. The model is based on resonant networks for the aorta and axillo-brachial-radial arterial system. The model chosen is a simple one, in order to make interpretation of the observed relationships clear. Despite its simplicity, the model produces realistic aortic and radial artery pressure waveforms. It demonstrates that the resonant properties of the arterial wall significantly alter the pressure waveform as it is propagated from the aorta to the radial artery. Although the mean and end-diastolic radial pressures are usually accurate estimates of the corresponding aortic pressures, the systolic pressure at the radial artery is often much higher than that of the aorta due to overshoot caused by the resonant behavior of the radial artery. The radial artery dicrotic notch is predominantly dependent on the axillo-brachial-radial arterial wall properties, rather than on the aortic valve or peripheral resistance. Hence the use of the radial artery dicrotic notch as an estimate of end systole is unreliable. The rate of systolic upstroke, dP/dt, of the radial artery waveform is a function of many factors, making it difficult to interpret. The radial artery waveform usually provides accurate estimates for mean and diastolic aortic pressures; for all other measurements it is an inadequate substitute for the aortic pressure waveform. In the presence of low forearm peripheral resistance the mean radial artery pressure may significantly underestimate the mean aortic pressure, as explained by a voltage divider model.

  3. Convergence patterns of the configuration-interaction expansion for excited 21S and 31S states of the helium atom

    International Nuclear Information System (INIS)

    Jankowski, K.; Malinowski, P.; Polasik, M.

    1977-01-01

    The convergence patterns of the l expansion of the wavefunction for the excited 2 1 S and 3 1 S states of the helium atom are studied by means of the variational method. Particular attention is devoted to the radial energy limits. (author)

  4. Relations among several nuclear and electronic density functional reactivity indexes

    Science.gov (United States)

    Torrent-Sucarrat, Miquel; Luis, Josep M.; Duran, Miquel; Toro-Labbé, Alejandro; Solà, Miquel

    2003-11-01

    An expansion of the energy functional in terms of the total number of electrons and the normal coordinates within the canonical ensemble is presented. A comparison of this expansion with the expansion of the energy in terms of the total number of electrons and the external potential leads to new relations among common density functional reactivity descriptors. The formulas obtained provide explicit links between important quantities related to the chemical reactivity of a system. In particular, the relation between the nuclear and the electronic Fukui functions is recovered. The connection between the derivatives of the electronic energy and the nuclear repulsion energy with respect to the external potential offers a proof for the "Quantum Chemical le Chatelier Principle." Finally, the nuclear linear response function is defined and the relation of this function with the electronic linear response function is given.

  5. Warp drive with zero expansion

    Energy Technology Data Exchange (ETDEWEB)

    Natario, Jose [Department of Mathematics, Instituto Superior Tecnico (Portugal)

    2002-03-21

    It is commonly believed that Alcubierre's warp drive works by contracting space in front of the warp bubble and expanding the space behind it. We show that this contraction/expansion is but a marginal consequence of the choice made by Alcubierre and explicitly construct a similar spacetime where no contraction/expansion occurs. Global and optical properties of warp-drive spacetimes are also discussed.

  6. Expansion lyre-shaped tube

    International Nuclear Information System (INIS)

    Andro, Jean.

    1973-01-01

    The invention relates the expansion lyre-shaped tube portions formed in dudgeoned tubular bundles between two bottom plates. An expansion lyre comprises at least two sets of tubes of unequal lengths coplanar and symmetrical with respect to the main tube axis, with connecting portions between the tubes forming said sets. The invention applies to apparatus such as heat exchangers, heaters, superheaters or breeders [fr

  7. Estimates of expansion time scales

    International Nuclear Information System (INIS)

    Jones, E.M.

    1979-01-01

    Monte Carlo simulations of the expansion of a spacefaring civilization show that descendants of that civilization should be found near virtually every useful star in the Galaxy in a time much less than the current age of the Galaxy. Only extreme assumptions about local population growth rates, emigration rates, or ship ranges can slow or halt an expansion. The apparent absence of extraterrestrials from the solar system suggests that no such civilization has arisen in the Galaxy. 1 figure

  8. Strategic Complexity and Global Expansion

    DEFF Research Database (Denmark)

    Oladottir, Asta Dis; Hobdari, Bersant; Papanastassiou, Marina

    2012-01-01

    The purpose of this paper is to analyse the determinants of global expansion strategies of newcomer Multinational Corporations (MNCs) by focusing on Iceland, Israel and Ireland. We argue that newcomer MNCs from small open economies pursue complex global expansion strategies (CGES). We distinguish....... The empirical evidence suggests that newcomer MNCs move away from simplistic dualities in the formulation of their strategic choices towards more complex options as a means of maintaining and enhancing their global competitiveness....

  9. Range expansion of heterogeneous populations.

    Science.gov (United States)

    Reiter, Matthias; Rulands, Steffen; Frey, Erwin

    2014-04-11

    Risk spreading in bacterial populations is generally regarded as a strategy to maximize survival. Here, we study its role during range expansion of a genetically diverse population where growth and motility are two alternative traits. We find that during the initial expansion phase fast-growing cells do have a selective advantage. By contrast, asymptotically, generalists balancing motility and reproduction are evolutionarily most successful. These findings are rationalized by a set of coupled Fisher equations complemented by stochastic simulations.

  10. MR accuracy and arthroscopic incidence of meniscal radial tears

    Energy Technology Data Exchange (ETDEWEB)

    Magee, Thomas; Shapiro, Marc; Williams, David [Department of Radiology, Neuroimaging Institute, 27 East Hibiscus Blvd., Melbourne, FL 32901 (United States)

    2002-12-01

    A meniscal radial tear is a vertical tear that involves the inner meniscal margin. The tear is most frequent in the middle third of the lateral meniscus and may extend outward in any direction. We report (1) the arthroscopic incidence of radial tears, (2) MR signs that aid in the detection of radial tears and (3) our prospective accuracy in detection of radial tears. Design and patients. Three musculoskeletal radiologists prospectively read 200 consecutive MR examinations of the knee that went on to arthroscopy by one orthopedic surgeon. MR images were assessed for location and MR characteristics of radial tears. MR criteria used for diagnosis of a radial tear were those outlined by Tuckman et al.: truncation, abnormal morphology and/or lack of continuity or absence of the meniscus on one or more MR images. An additional criterion used was abnormal increased signal in that area on fat-saturated proton density or T2-weighted coronal and sagittal images. Prospective MR readings were correlated with the arthroscopic findings.Results. Of the 200 consecutive knee arthroscopies, 28 patients had radial tears reported arthroscopically (14% incidence). MR readings prospectively demonstrated 19 of the 28 radial tears (68% sensitivity) when the criteria for diagnosis of a radial tear were truncation or abnormal morphology of the meniscus. With the use of the additional criterion of increased signal in the area of abnormal morphology on fat-saturated T2-weighted or proton density weighted sequences, the prospective sensitivity was 25 of 28 radial tears (89% sensitivity). There were no radial tears described in MR reports that were not demonstrated on arthroscopy (i.e., there were no false positive MR readings of radial tears in these 200 patients). Radial tears are commonly seen at arthroscopy. There was a 14% incidence in this series of 200 patients who underwent arthroscopy. Prospective detection of radial tears was 68% as compared with arthroscopy when the criteria as

  11. MR accuracy and arthroscopic incidence of meniscal radial tears

    International Nuclear Information System (INIS)

    Magee, Thomas; Shapiro, Marc; Williams, David

    2002-01-01

    A meniscal radial tear is a vertical tear that involves the inner meniscal margin. The tear is most frequent in the middle third of the lateral meniscus and may extend outward in any direction. We report (1) the arthroscopic incidence of radial tears, (2) MR signs that aid in the detection of radial tears and (3) our prospective accuracy in detection of radial tears. Design and patients. Three musculoskeletal radiologists prospectively read 200 consecutive MR examinations of the knee that went on to arthroscopy by one orthopedic surgeon. MR images were assessed for location and MR characteristics of radial tears. MR criteria used for diagnosis of a radial tear were those outlined by Tuckman et al.: truncation, abnormal morphology and/or lack of continuity or absence of the meniscus on one or more MR images. An additional criterion used was abnormal increased signal in that area on fat-saturated proton density or T2-weighted coronal and sagittal images. Prospective MR readings were correlated with the arthroscopic findings.Results. Of the 200 consecutive knee arthroscopies, 28 patients had radial tears reported arthroscopically (14% incidence). MR readings prospectively demonstrated 19 of the 28 radial tears (68% sensitivity) when the criteria for diagnosis of a radial tear were truncation or abnormal morphology of the meniscus. With the use of the additional criterion of increased signal in the area of abnormal morphology on fat-saturated T2-weighted or proton density weighted sequences, the prospective sensitivity was 25 of 28 radial tears (89% sensitivity). There were no radial tears described in MR reports that were not demonstrated on arthroscopy (i.e., there were no false positive MR readings of radial tears in these 200 patients). Radial tears are commonly seen at arthroscopy. There was a 14% incidence in this series of 200 patients who underwent arthroscopy. Prospective detection of radial tears was 68% as compared with arthroscopy when the criteria as

  12. Electrospinning of reactive mesogens

    NARCIS (Netherlands)

    Yao, J.; Picot, O.T.; Hughes-Brittain, N.F.; Bastiaansen, C.W.M.; Peijs, T.

    2016-01-01

    The reinforcement potential of reactive liquid crystals or reactive mesogens (RMs) in electrospun fibers was investigated through the blending of two types of RMs (RM257 and RM82) with two types of thermoplastics; polyamide 6 (PA6) and poly(methyl methacrylate) (PMMA). Polymer/RM blends were

  13. Radial propagation of microturbulence in tokamaks

    International Nuclear Information System (INIS)

    Garbet, X.; Laurent, L.; Roubin, J.P.; Samain, A.

    1992-01-01

    Energy confinement time in tokamaks exhibits a clear dependence on global plasma parameters. This is not the case for transport coefficients; their dependence on local plasma parameters cannot be precisely established. The aim of the present paper is to give a possible explanation of this behaviour; turbulence propagates radially because of departure from cylindrical geometry. This implies that the turbulence level at a given point and hence transport coefficients are not only functions of local plasma parameters. A quantitative estimate of the propagation velocity is derived from a Lagrangian formalism. Two cases are considered: the effect of toroidicity and the effect of non linear mode-mode coupling. The consequences of this model are discussed. This process does not depend on the type of instability. For the sake of simplicity only electrostatic perturbations are considered

  14. Radial particle distributions in PARMILA simulation beams

    International Nuclear Information System (INIS)

    Boicourt, G.P.

    1984-03-01

    The estimation of beam spill in particle accelerators is becoming of greater importance as higher current designs are being funded. To the present, no numerical method for predicting beam-spill has been available. In this paper, we present an approach to the loss-estimation problem that uses probability distributions fitted to particle-simulation beams. The properties of the PARMILA code's radial particle distribution are discussed, and a broad class of probability distributions are examined to check their ability to fit it. The possibility that the PARMILA distribution is a mixture is discussed, and a fitting distribution consisting of a mixture of two generalized gamma distributions is found. An efficient algorithm to accomplish the fit is presented. Examples of the relative prediction of beam spill are given. 26 references, 18 figures, 1 table

  15. Hydrostatic radial bearing of centrifugal pump

    International Nuclear Information System (INIS)

    Skalicky, A.

    1976-01-01

    A hydrostatic radial pump is described characterized by the fact that part of the medium off-taken from delivery is used as a lubricating medium. Two additional bodies are placed alongside a hydrostatic bearing with coils in between them and the pump shaft; the coils have an opposite pitch. The feed channel for the hydrostatic bearing pocket is linked to delivery. The coil outlets are connected to the pump suction unit. Two rotating coils placed alongside the hydrostatic bearing will considerably simplify the communication channel design and reduce the dependence on the pump shaft deflections. The addition of another rotating coil in the close vicinity of the pump shaft or directly on the shaft further increases the efficiency. The bearing can be used in designing vertical circulating pumps for the cooling circuits of nuclear reactors. (J.B.)

  16. The radial velocity variations in IC 418

    International Nuclear Information System (INIS)

    Mendez, R.H.; Verga, A.D.

    1981-01-01

    The observations presented are part of a search for spectral and radial velocity variations among central stars of planetary nebulae and include the following new data: 1) Weak, previously undetected C III emissions are visible at 4056, 4186, 4516, 5270 and 5826 A. The famous unidentified emissions at 4485 and 4503 A were also found. 2) The He I absorptions at 4471 and 5875 A are blue-shifted relative to the nebular emissions. The same happens with Hsub(delta) and Hsub(γ), although in this case the shift can be at least partly attributed to blends with the strong He II absorptions, which are estimated to contribute about one half of the equivalent width at Hsub(delta) and Hsub(γ). 3) O III 5592 and C IV 5801, 5811 are also found in absorption. (Auth.)

  17. Doubly stochastic radial basis function methods

    Science.gov (United States)

    Yang, Fenglian; Yan, Liang; Ling, Leevan

    2018-06-01

    We propose a doubly stochastic radial basis function (DSRBF) method for function recoveries. Instead of a constant, we treat the RBF shape parameters as stochastic variables whose distribution were determined by a stochastic leave-one-out cross validation (LOOCV) estimation. A careful operation count is provided in order to determine the ranges of all the parameters in our methods. The overhead cost for setting up the proposed DSRBF method is O (n2) for function recovery problems with n basis. Numerical experiments confirm that the proposed method not only outperforms constant shape parameter formulation (in terms of accuracy with comparable computational cost) but also the optimal LOOCV formulation (in terms of both accuracy and computational cost).

  18. Anomalous Medial Branch of Radial Artery: A Rare Variant

    Directory of Open Access Journals (Sweden)

    Surbhi Wadhwa

    2016-10-01

    Full Text Available Radial artery is an important consistent vessel of the upper limb. It is a useful vascular access site for coronary procedures and its reliable anatomy has resulted in an elevation of radial forearm flaps for reconstructive surgeries of head and neck. Technical failures, in both the procedures, are mainly due to anatomical variations, such as radial loops, ectopic radial arteries or tortuosity in the vessel. We present a rare and a unique anomalous medial branch of the radial artery spiraling around the flexor carpi radialis muscle in the forearm with a high rising superficial palmar branch of radial artery. Developmentally it probably is a remanent of the normal pattern of capillary vessel maintenance and regression. Such a case is of importance for reconstructive surgeons and coronary interventionists, especially in view of its unique medial and deep course.

  19. Radial extension of drift waves in presence of velocity profiles

    International Nuclear Information System (INIS)

    Sen, S.; Weiland, J.

    1994-01-01

    The effect of a radially varying poloidal velocity field on the recently found radially extended toroidal drift waves is investigated analytically. The role of velocity curvature (υ φ '') is found to have robust effects on the radial model structure of the mode. For a positive value of the curvature (Usually found in the H-mode edges) the radial model envelope, similar to the sheared slab case, becomes fully outgoing. The mode is therefore stable. On the other hand, for a negative value of the curvature (usually observed in the L-mode edges) all the characteristics of conventional drift waves return back. The radial mode envelope reduces to a localized Gaussian shape and the mode is therefore unstable again for typical (magnetic) shear values in tokamaks. Velocity shear (υ φ ??) on the other hand is found to have rather insignificant role both in determining the radial model structure and stability

  20. Radial-Electric-Field Piezoelectric Diaphragm Pumps

    Science.gov (United States)

    Bryant, Robert G.; Working, Dennis C.; Mossi, Karla; Castro, Nicholas D.; Mane, Pooma

    2009-01-01

    In a recently invented class of piezoelectric diaphragm pumps, the electrode patterns on the piezoelectric diaphragms are configured so that the electric fields in the diaphragms have symmetrical radial (along-the-surface) components in addition to through-the-thickness components. Previously, it was accepted in the piezoelectric-transducer art that in order to produce the out-of-plane bending displacement of a diaphragm needed for pumping, one must make the electric field asymmetrical through the thickness, typically by means of electrodes placed on only one side of the piezoelectric material. In the present invention, electrodes are placed on both sides and patterned so as to produce substantial radial as well as through-the-thickness components. Moreover, unlike in the prior art, the electric field can be symmetrical through the thickness. Tests have shown in a given diaphragm that an electrode configuration according to this invention produces more displacement than does a conventional one-sided electrode pattern. The invention admits of numerous variations characterized by various degrees of complexity. Figure 1 is a simplified depiction of a basic version. As in other piezoelectric diaphragm pumps of similar basic design, the prime mover is a piezoelectric diaphragm. Application of a suitable voltage to the electrodes on the diaphragm causes it to undergo out-of-plane bending. The bending displacement pushes a fluid out of, or pulls the fluid into, a chamber bounded partly by the diaphragm. Also as in other diaphragm pumps in general, check valves ensure that the fluid flows only in through one port and only out through another port.

  1. Radial stability of anisotropic strange quark stars

    Energy Technology Data Exchange (ETDEWEB)

    Arbañil, José D.V.; Malheiro, M., E-mail: jose.arbanil@upn.pe, E-mail: malheiro@ita.br [ITA—Instituto Tecnológico de Aeronáutica—Departamento de Física, 12228-900, São José dos Campos, São Paulo (Brazil)

    2016-11-01

    The influence of the anisotropy in the equilibrium and stability of strange stars is investigated through the numerical solution of the hydrostatic equilibrium equation and the radial oscillation equation, both modified from their original version to include this effect. The strange matter inside the quark stars is described by the MIT bag model equation of state. For the anisotropy two different kinds of local anisotropic σ = p {sub t} − p {sub r} are considered, where p {sub t} and p {sub r} are respectively the tangential and the radial pressure: one that is null at the star's surface defined by p {sub r} ( R ) = 0, and one that is nonnull at the surface, namely, σ {sub s} = 0 and σ {sub s} {sub ≠} {sub 0}. In the case σ {sub s} = 0, the maximum mass value and the zero frequency of oscillation are found at the same central energy density, indicating that the maximum mass marks the onset of the instability. For the case σ {sub s} {sub ≠} {sub 0}, we show that the maximum mass point and the zero frequency of oscillation coincide in the same central energy density value only in a sequence of equilibrium configurations with the same value of σ {sub s} . Thus, the stability star regions are determined always by the condition dM / d ρ {sub c} {sub >} {sub 0} only when the tangential pressure is maintained fixed at the star surface's p {sub t} ( R ). These results are also quite important to analyze the stability of other anisotropic compact objects such as neutron stars, boson stars and gravastars.

  2. A New Filtering Algorithm Utilizing Radial Velocity Measurement

    Institute of Scientific and Technical Information of China (English)

    LIU Yan-feng; DU Zi-cheng; PAN Quan

    2005-01-01

    Pulse Doppler radar measurements consist of range, azimuth, elevation and radial velocity. Most of the radar tracking algorithms in engineering only utilize position measurement. The extended Kalman filter with radial velocity measureneut is presented, then a new filtering algorithm utilizing radial velocity measurement is proposed to improve tracking results and the theoretical analysis is also given. Simulation results of the new algorithm, converted measurement Kalman filter, extended Kalman filter are compared. The effectiveness of the new algorithm is verified by simulation results.

  3. Vitreous veils and radial lattice in Marshall syndrome.

    Science.gov (United States)

    Brubaker, Jacob W; Mohney, Brian G; Pulido, Jose S; Babovic-Vuksanovic, Dusica

    2008-12-01

    To report the findings of membranous vitreous veils and radial lattice in a child with Marshall syndrome. Observational case report. Retrospective review of medical records and fundus photograph of a 6-year-old boy with Marshall syndrome. Vitreoretinal findings were significant for bilateral membranous vitreous veils and radial lattice degeneration. This case demonstrates the occurrence of vitreous veils and radial lattice degeneration in patients with Marshall syndrome.

  4. Reduction of thermal expansion in Z-pinches by electron beam assisted magnetic field generation

    International Nuclear Information System (INIS)

    Heikkinen, J.A.; Karttunen, S.J.

    1989-01-01

    Weak radial expansion of a Z-pinch plasma column during its strong initial ohmic heating phase is expected when the generation of a confining magnetic field is assisted by a correctly formed electron beam pulse. Appropriate one-dimensional magnetohydrodynamic equations are numerically solved, and the observed increase of plasma radius as a function of time for various discharge parameters is compared to a normal Z-pinch discharge initiation. (author)

  5. Pseudarthrosis of radial shaft with dislocation of heads of radial and ulnar bones (case report

    Directory of Open Access Journals (Sweden)

    M. E. Puseva

    2013-01-01

    Full Text Available The authors presented a rare clinical case - the injury of forearm complicated by the formation of the pseudarthrosis of the radial shaft in combination with old dislocation of heads the radius and ulna. The differentiated approach to the choice of surgical tactics was proposed, which consists of several consistent stages: taking free autotransplant from the crest of iliac bone, resection of pseudarthrosis of radius with replacement of the bone defect by the graft for restoration of anatomic length, conducting combined strained osteosynthesis and elimination of dislocation of a head of radial and ulnar bones by transosseous osteosynthesis. The chosen treatment strategy allowed to restore the anatomy and function of the upper extremity.

  6. Major genomic mitochondrial lineages delineate early human expansions

    Directory of Open Access Journals (Sweden)

    Flores Carlos

    2001-08-01

    Full Text Available Abstract Background The phylogeographic distribution of human mitochondrial DNA variations allows a genetic approach to the study of modern Homo sapiens dispersals throughout the world from a female perspective. As a new contribution to this study we have phylogenetically analysed complete mitochondrial DNA(mtDNA sequences from 42 human lineages, representing major clades with known geographic assignation. Results We show the relative relationships among the 42 lineages and present more accurate temporal calibrations than have been previously possible to give new perspectives as how modern humans spread in the Old World. Conclusions The first detectable expansion occurred around 59,000–69,000 years ago from Africa, independently colonizing western Asia and India and, following this southern route, swiftly reaching east Asia. Within Africa, this expansion did not replace but mixed with older lineages detectable today only in Africa. Around 39,000–52,000 years ago, the western Asian branch spread radially, bringing Caucasians to North Africa and Europe, also reaching India, and expanding to north and east Asia. More recent migrations have entangled but not completely erased these primitive footprints of modern human expansions.

  7. Theoretical and experimental studies of the orbit expansion effect

    International Nuclear Information System (INIS)

    Glazov, A.A.; Denisov, Yu.N.; Dmitrievskij, V.P.

    1985-01-01

    Calculation and experiment results of investigations on the orbit expansion effect in the periodic magnetic structures are considered. Experiments, conducted with the use of ring cyclotron electron model, have shown, that the orbit expansion effect leads to the beam cross section radial size increase. This phenomenon was eliminated through the introduction of correction coils, which provide for the required low harmonic phase and value change in the whole acceleration area. Energy spread leads to the spreading of beam in the expansion area. Numeric calculations show, that for the electron model used the relative energy spread must be less than 10 -3 . The conclusion is drawn, that the only real possibility to obtain an accelerated beam with such an energy spread is to perform the ''flat-top'' regime. Equipment for cyclotron electron model RF supply is developed and produced to realise this regime. Particle dinamics calculation in the ''flat-top'' regime and the first experiments have shown, that acceleration asymmetry leads to the rapid coherent oscillation swing in the centre up to the amplitude of 6-7 sm

  8. Numerical simulation of liquid-metal-flows in radial-toroidal-radial bends

    International Nuclear Information System (INIS)

    Molokov, S.; Buehler, L.

    1993-09-01

    Magnetohydrodynamic flows in a U-bend and right-angle bend are considered with reference to the radial-toroidal-radial concept of a self-cooled liquid-metal blanket. The ducts composing bends have rectangular cross-section. The applied magnetic field is aligned with the toroidal duct and perpendicular to the radial ones. At high Hartmann number the flow region is divided into cores and boundary layers of different types. The magnetohydrodynamic equations are reduced to a system of partial differential equations governing wall electric potentials and the core pressure. The system is solved numerically by two different methods. The first method is iterative with iteration between wall potential and the core pressure. The second method is a general one for the solution of the core flow equations in curvilinear coordinates generated by channel geometry and magnetic field orientation. Results obtained are in good agreement. They show, that the 3D-pressure drop of MHD flows in a U-bend is not a critical issue for blanket applications. (orig./HP) [de

  9. Fuel radial design using Path Relinking; Diseno radial de combustible usando Path Relinking

    Energy Technology Data Exchange (ETDEWEB)

    Campos S, Y. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)

    2007-07-01

    The present work shows the obtained results when implementing the combinatory optimization technique well-known as Path Re linking (Re-linkage of Trajectories), to the problem of the radial design of nuclear fuel assemblies, for boiling water reactors (BWR Boiling Water Reactor by its initials in English), this type of reactors is those that are used in the Laguna Verde Nucleo electric Central, Veracruz. As in any other electric power generation plant of that make use of some fuel to produce heat and that it needs each certain time (from 12 to 14 months) to make a supply of the same one, because this it wears away or it burns, in the nucleolectric plants to this activity is denominated fuel reload. In this reload different activities intervene, among those which its highlight the radial and axial designs of fuel assemblies, the patterns of control rods and the multi cycles study, each one of these stages with their own complexity. This work was limited to study in independent form the radial design, without considering the other activities. These phases are basic for the fuel reload design and of reactor operation strategies. (Author)

  10. On genus expansion of superpolynomials

    Energy Technology Data Exchange (ETDEWEB)

    Mironov, Andrei, E-mail: mironov@itep.ru [Lebedev Physics Institute, Moscow 119991 (Russian Federation); ITEP, Moscow 117218 (Russian Federation); National Research Nuclear University MEPhI, Moscow 115409 (Russian Federation); Morozov, Alexei, E-mail: morozov@itep.ru [ITEP, Moscow 117218 (Russian Federation); National Research Nuclear University MEPhI, Moscow 115409 (Russian Federation); Sleptsov, Alexei, E-mail: sleptsov@itep.ru [ITEP, Moscow 117218 (Russian Federation); Laboratory of Quantum Topology, Chelyabinsk State University, Chelyabinsk 454001 (Russian Federation); KdVI, University of Amsterdam (Netherlands); Smirnov, Andrey, E-mail: asmirnov@math.columbia.edu [ITEP, Moscow 117218 (Russian Federation); Columbia University, Department of Mathematics, New York (United States)

    2014-12-15

    Recently it was shown that the (Ooguri–Vafa) generating function of HOMFLY polynomials is the Hurwitz partition function, i.e. that the dependence of the HOMFLY polynomials on representation R is naturally captured by symmetric group characters (cut-and-join eigenvalues). The genus expansion and expansion through Vassiliev invariants explicitly demonstrate this phenomenon. In the present paper we claim that the superpolynomials are not functions of such a type: symmetric group characters do not provide an adequate linear basis for their expansions. Deformation to superpolynomials is, however, straightforward in the multiplicative basis: the Casimir operators are β-deformed to Hamiltonians of the Calogero–Moser–Sutherland system. Applying this trick to the genus and Vassiliev expansions, we observe that the deformation is fully straightforward only for the thin knots. Beyond the family of thin knots additional algebraically independent terms appear in the Vassiliev and genus expansions. This can suggest that the superpolynomials do in fact contain more information about knots than the colored HOMFLY and Kauffman polynomials. However, even for the thin knots the beta-deformation is non-innocent: already in the simplest examples it seems inconsistent with the positivity of colored superpolynomials in non-(anti)symmetric representations, which also happens in I. Cherednik's (DAHA-based) approach to the torus knots.

  11. Design of radial reinforcement for prestressed concrete containments

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shen, E-mail: swang@bechtel.com [Bechtel Power Corporation, 5275 Westview Drive, BP2-2C3, Frederick, MD 21703 (United States); Munshi, Javeed A., E-mail: jamunshi@bechtel.com [Bechtel Power Corporation, 5275 Westview Drive, BP2-2C3, Frederick, MD 21703 (United States)

    2013-02-15

    Highlights: ► A rigorous formulae is proposed to calculate radial stress within prestressed concrete containments. ► The proposed method is validated by finite element analysis in an illustrative practical example. ► A partially prestressed condition is more critical than a fully prestressed condition for radial tension. ► Practical design consideration is provided for detailing of radial reinforcement. -- Abstract: Nuclear containments are critical components for safety of nuclear power plants. Failure can result in catastrophic safety consequences as a result of leakage of radiation. Prestressed concrete containments have been used in large nuclear power plants with significant design internal pressure. These containments are generally reinforced with prestressing tendons in the circumferential (hoop) and meridional (vertical) directions. The curvature effect of the tendons introduces radial tensile stresses in the concrete shell which are generally neglected in the design of such structures. It is assumed that such tensile radial stresses are small as such no radial reinforcement is provided for this purpose. But recent instances of significant delaminations in Crystal River Unit 3 in Florida have elevated the need for reevaluation of the radial tension issue in prestressed containment. Note that currently there are no well accepted industry standards for design and detailing of radial reinforcement. This paper discusses the issue of radial tension in prestressed cylindrical and dome shaped structures and proposes formulae to calculate radial stresses. A practical example is presented to illustrate the use of the proposed method which is then verified by using state of art finite element analysis. This paper also provides some practical design consideration for detailing of radial reinforcement in prestressed containments.

  12. Low Thermal Expansion Glass Ceramics

    CERN Document Server

    Bach, Hans

    2005-01-01

    This book appears in the authoritative series reporting the international research and development activities conducted by the Schott group of companies. This series provides an overview of Schott's activities for scientists, engineers, and managers from all branches of industry worldwide in which glasses and glass ceramics are of interest. Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated. This new extended edition describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics. The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions. Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization. Thus g...

  13. Low thermal expansion glass ceramics

    CERN Document Server

    1995-01-01

    This book is one of a series reporting on international research and development activities conducted by the Schott group of companies With the series, Schott aims to provide an overview of its activities for scientists, engineers, and managers from all branches of industry worldwide where glasses and glass ceramics are of interest Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated This volume describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization Thus glass ceramics with thermal c...

  14. Regulation of gas infrastructure expansion

    International Nuclear Information System (INIS)

    De Joode, J.

    2012-01-01

    The topic of this dissertation is the regulation of gas infrastructure expansion in the European Union (EU). While the gas market has been liberalised, the gas infrastructure has largely remained in the regulated domain. However, not necessarily all gas infrastructure facilities - such as gas storage facilities, LNG import terminals and certain gas transmission pipelines - need to be regulated, as there may be scope for competition. In practice, the choice of regulation of gas infrastructure expansion varies among different types of gas infrastructure facilities and across EU Member States. Based on a review of economic literature and on a series of in-depth case studies, this study explains these differences in choices of regulation from differences in policy objectives, differences in local circumstances and differences in the intrinsic characteristics of the infrastructure projects. An important conclusion is that there is potential for a larger role for competition in gas infrastructure expansion.

  15. EBRPOCO - a program to calculate detailed contributions of power reactivity components of EBR-II

    International Nuclear Information System (INIS)

    Meneghetti, D.; Kucera, D.A.

    1981-01-01

    The EBRPOCO program has been developed to facilitate the calculations of the power coefficients of reactivity of EBR-II loadings. The program enables contributions of various components of the power coefficient to be delineated axially for every subassembly. The program computes the reactivity contributions of the power coefficients resulting from: density reduction of sodium coolant due to temperature; displacement of sodium coolant by thermal expansions of cladding, structural rods, subassembly cans, and lower and upper axial reflectors; density reductions of these steel components due to temperature; displacement of bond-sodium (if present) in gaps by differential thermal expansions of fuel and cladding; density reduction of bond-sodium (if present) in gaps due to temperature; free axial expansion of fuel if unrestricted by cladding or restricted axial expansion of fuel determined by axial expansion of cladding. Isotopic spatial contributions to the Doppler component my also be obtained. (orig.) [de

  16. Digital reactivity meter

    International Nuclear Information System (INIS)

    Jiang Zongbing

    1996-02-01

    The importance and the usual methods of reactivity measurement in a nuclear reactor are presented. Emphasis is put upon the calculation principle, software and hardware components, main specifications, application, as well as the features of the digital reactivity meter. The test results of operation in various reactors shown that the meter possess the following features: high accuracy, short response time, low output noise, high resolution, wide measuring range, simple and flexible to operate, high stability and reliability. In addition, the reactivity meter can save the measuring data automatically and have a perfect capability of self-verifying. It not only meet the requirement of the reactivity measurement in nuclear power plant, but also can be applied to various types of reactors. (1 tab.)

  17. Stress Reactivity in Insomnia.

    Science.gov (United States)

    Gehrman, Philip R; Hall, Martica; Barilla, Holly; Buysse, Daniel; Perlis, Michael; Gooneratne, Nalaka; Ross, Richard J

    2016-01-01

    This study examined whether individuals with primary insomnia (PI) are more reactive to stress than good sleepers (GS). PI and GS (n = 20 per group), matched on gender and age, completed three nights of polysomnography. On the stress night, participants received a mild electric shock and were told they could receive additional shocks during the night. Saliva samples were obtained for analysis of cortisol and alpha amylase along with self-report and visual analog scales (VAS). There was very little evidence of increased stress on the stress night, compared to the baseline night. There was also no evidence of greater stress reactivity in the PI group for any sleep or for salivary measures. In the GS group, stress reactivity measured by VAS scales was positively associated with an increase in sleep latency in the experimental night on exploratory analyses. Individuals with PI did not show greater stress reactivity compared to GS.

  18. Structure, Reactivity and Dynamics

    Indian Academy of Sciences (India)

    Understanding structure, reactivity and dynamics is the core issue in chemical ... functional theory (DFT) calculations, molecular dynamics (MD) simulations, light- ... between water and protein oxygen atoms, the superionic conductors which ...

  19. Taskable Reactive Agent Communities

    National Research Council Canada - National Science Library

    Myers, Karen

    2002-01-01

    The focus of Taskable Reactive Agent Communities (TRAC) project was to develop mixed-initiative technology to enable humans to supervise and manage teams of agents as they perform tasks in dynamic environments...

  20. The loop expansion as a divergent-power-series expansion

    International Nuclear Information System (INIS)

    Murai, N.

    1981-01-01

    The loop expansion should be divergent, possibly an asymptotic one, in the Euclidean path integral formulation. This consideration is important in applications of the symmetric and mass-independent renormalization. The [1,1] Pade approximant is calculated in a PHI 4 model. Its classical vacua may be not truely stable for nonzero coupling constant. (author)

  1. Cosmological expansion and local physics

    International Nuclear Information System (INIS)

    Faraoni, Valerio; Jacques, Audrey

    2007-01-01

    The interplay between cosmological expansion and local attraction in a gravitationally bound system is revisited in various regimes. First, weakly gravitating Newtonian systems are considered, followed by various exact solutions describing a relativistic central object embedded in a Friedmann universe. It is shown that the 'all or nothing' behavior recently discovered (i.e., weakly coupled systems are comoving while strongly coupled ones resist the cosmic expansion) is limited to the de Sitter background. New exact solutions are presented which describe black holes perfectly comoving with a generic Friedmann universe. The possibility of violating cosmic censorship for a black hole approaching the big rip is also discussed

  2. Temperature expansions for magnetic systems

    International Nuclear Information System (INIS)

    Cangemi, D.; Dunne, G.

    1996-01-01

    We derive finite temperature expansions for relativistic fermion systems in the presence of background magnetic fields, and with nonzero chemical potential. We use the imaginary-time formalism for the finite temperature effects, the proper-time method for the background field effects, and zeta function regularization for developing the expansions. We emphasize the essential difference between even and odd dimensions, focusing on 2+1 and 3+1 dimensions. We concentrate on the high temperature limit, but we also discuss the T=0 limit with nonzero chemical potential. Copyright copyright 1996 Academic Press, Inc

  3. Observational hints of radial migration in disc galaxies from CALIFA

    NARCIS (Netherlands)

    Ruiz-Lara, T.; Pérez, I.; Florido, E.; Sánchez-Blázquez, P.; Méndez-Abreu, J.; Sánchez-Menguiano, L.; Sánchez, S. F.; Lyubenova, M.; Falcón-Barroso, J.; van de Ven, G.; Marino, R. A.; de Lorenzo-Cáceres, A.; Catalán-Torrecilla, C.; Costantin, L.; Bland-Hawthorn, J.; Galbany, L.; García-Benito, R.; Husemann, B.; Kehrig, C.; Márquez, I.; Mast, D.; Walcher, C. J.; Zibetti, S.; Ziegler, B.

    2017-01-01

    Context. According to numerical simulations, stars are not always kept at their birth galactocentric distances but they have a tendency to migrate. The importance of this radial migration in shaping galactic light distributions is still unclear. However, if radial migration is indeed important,

  4. Radial supports of face motors with slack compensation

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsova, I I; Gelman, A B; Krekina, T V

    1982-01-01

    The design of a radial support of a face motor with slack compensation is described, and gives the results of field tests which confirm the performance capacity of the experimental support both from the viewpoint of durability, and in relation to preventing radial slack of the face motor shaft.

  5. Radial Color Gradient in a Globular Cluster 1. M68

    Directory of Open Access Journals (Sweden)

    Sukyoung Yi

    1990-12-01

    Full Text Available Stars in M68 from the observed color-magnitude diagrams with CCD were integrated to find any radial gradient. The result shows that M68 has a slightly bluer core. The main cause of these calculated radial color variations seems to come from the random distribution of giants.

  6. Modelling and analysis of radial thermal stresses and temperature ...

    African Journals Online (AJOL)

    A theoretical investigation has been undertaken to study operating temperatures, heat fluxes and radial thermal stresses in the valves of a modern diesel engine with and without air-cavity. Temperatures, heat fluxes and radial thermal stresses were measured theoretically for both cases under all four thermal loading ...

  7. Radiographic study of distal radial physeal closure in thoroughbred horses

    International Nuclear Information System (INIS)

    Vulcano, L.C.; Mamprim, M.J.; Muniz, L.M.R.; Moreira, A.F.; Luna, S.P.L.

    1997-01-01

    Monthly radiography was performed to study distal radial physeal closure in ten male and ten female Throughbred horses. The height, thoracic circumference and metacarpus circumference were also measured, Distal radial physeal closure time was sooner in females than males, and took 701 +/- 37 and 748 +/- 55 days respectively

  8. Reactive sputter deposition

    CERN Document Server

    Mahieu, Stijn

    2008-01-01

    In this valuable work, all aspects of the reactive magnetron sputtering process, from the discharge up to the resulting thin film growth, are described in detail, allowing the reader to understand the complete process. Hence, this book gives necessary information for those who want to start with reactive magnetron sputtering, understand and investigate the technique, control their sputtering process and tune their existing process, obtaining the desired thin films.

  9. Radial Velocities of 41 Kepler Eclipsing Binaries

    Science.gov (United States)

    Matson, Rachel A.; Gies, Douglas R.; Guo, Zhao; Williams, Stephen J.

    2017-12-01

    Eclipsing binaries are vital for directly determining stellar parameters without reliance on models or scaling relations. Spectroscopically derived parameters of detached and semi-detached binaries allow us to determine component masses that can inform theories of stellar and binary evolution. Here we present moderate resolution ground-based spectra of stars in close binary systems with and without (detected) tertiary companions observed by NASA’s Kepler mission and analyzed for eclipse timing variations. We obtain radial velocities and spectroscopic orbits for five single-lined and 35 double-lined systems, and confirm one false positive eclipsing binary. For the double-lined spectroscopic binaries, we also determine individual component masses and examine the mass ratio {M}2/{M}1 distribution, which is dominated by binaries with like-mass pairs and semi-detached classical Algol systems that have undergone mass transfer. Finally, we constrain the mass of the tertiary component for five double-lined binaries with previously detected companions.

  10. Nonlinear radial propagation of drift wave turbulence

    International Nuclear Information System (INIS)

    Prakash, M.

    1985-01-01

    We study the linear and the nonlinear radial propagation of drift wave energy in an inhomogeneous plasma. The drift mode excited in such a plasma is dispersive in nature. The drift wave energy spreads out symmetrically along the direction of inhomogeneity with a finite group velocity. To study the effect of the nonlinear coupling on the propagation of energy in a collision free plasma, we solve the Hasegawa-Mima equation as a mixed initial boundary-value problem. The solutions of the linearized equation are used to check the reliability of our numerical calculations. Additional checks are also performed on the invariants of the system. Our results reveal that a pulse gets distorted as it propagates through the medium. The peak of the pulse propagates with a finite velocity that depends on the amplitude of the initial pulse. The polarity of propagation depends on the initial parameters of the pulse. We have also studied drift wave propagation in a resistive plasma. The Hasegawa-Wakatani equations are used to investigate this problem

  11. THE NIRSPEC ULTRACOOL DWARF RADIAL VELOCITY SURVEY

    International Nuclear Information System (INIS)

    Blake, Cullen H.; Charbonneau, David; White, Russel J.

    2010-01-01

    We report the results of an infrared Doppler survey designed to detect brown dwarf and giant planetary companions to a magnitude-limited sample of ultracool dwarfs. Using the NIRSPEC spectrograph on the Keck II telescope, we obtained approximately 600 radial velocity (RV) measurements over a period of six years of a sample of 59 late-M and L dwarfs spanning spectral types M8/L0 to L6. A subsample of 46 of our targets has been observed on three or more epochs. We rely on telluric CH 4 absorption features in Earth's atmosphere as a simultaneous wavelength reference and exploit the rich set of CO absorption features found in the K-band spectra of cool stars and brown dwarfs to measure RVs and projected rotational velocities. For a bright, slowly rotating M dwarf standard we demonstrate an RV precision of 50 m s -1 and for slowly rotating L dwarfs we achieve a typical RV precision of approximately 200 m s -1 . This precision is sufficient for the detection of close-in giant planetary companions to mid-L dwarfs as well as more equal mass spectroscopic binary systems with small separations (a +0.7 -0.6 Gyr, similar to that of nearby sun-like stars. We simulate the efficiency with which we detect spectroscopic binaries and find that the rate of tight (a +8.6 -1.6 %, consistent with recent estimates in the literature of a tight binary fraction of 3%-4%.

  12. Vortex Ring Dynamics in Radially Confined Domains

    Science.gov (United States)

    Stewart, Kelley; Niebel, Casandra; Jung, Sunghwan; Vlachos, Pavlos

    2010-11-01

    Vortex ring dynamics have been studied extensively in semi-infinite quiescent volumes. However, very little is known about vortex-ring formation in wall-bounded domains where vortex wall interaction will affect both the vortex ring pinch-off and propagation velocity. This study addresses this limitation and studies vortex formation in radially confined domains to analyze the affect of vortex-ring wall interaction on the formation and propagation of the vortex ring. Vortex rings were produced using a pneumatically driven piston cylinder arrangement and were ejected into a long cylindrical tube which defined the confined downstream domain. A range of confinement domains were studied with varying confinement diameters Velocity field measurements were performed using planar Time Resolved Digital Particle Image Velocimetry (TRDPIV) and were processed using an in-house developed cross-correlation PIV algorithm. The experimental analysis was used to facilitate the development of a theoretical model to predict the variations in vortex ring circulation over time within confined domains.

  13. Energy expansion planning by considering electrical and thermal expansion simultaneously

    International Nuclear Information System (INIS)

    Abbasi, Ali Reza; Seifi, Ali Reza

    2014-01-01

    Highlights: • This paper focused on the expansion planning optimization of energy systems. • Employing two form of energy: the expansion of electrical and thermal energies. • The main objective is to minimize the costs. • A new Modified Honey Bee Mating Optimization (MHBMO) algorithm is applied. - Abstract: This study focused on the expansion planning optimization of energy systems employing two forms of energy: the expansion of electrical and thermal energies simultaneously. The main objective of this investigation is confirming network adequacy by adding new equipment to the network, over a given planning horizon. The main objective of the energy expansion planning (EEP) is to minimize the real energy loss, voltage deviation and the total cost of installation equipments. Since the objectives are different and incommensurable, it is difficult to solve the problem by the conventional approaches that may optimize a single objective. So, the meta-heuristic algorithm is applied to this problem. Here, Honey Bee Mating Optimization algorithm (HBMO) as a new evolutionary optimization algorithm is utilized. In order to improve the total ability of HBMO for the global search and exploration, a new modification process is suggested such a way that the algorithm will search the total search space globally. Also, regarding the uncertainties of the new complicated energy systems, in this paper for the first time, the EEP problem is investigated in a stochastic environment by the use of probabilistic load flow technique based on Point Estimate Method (PEM). In order to evaluate the feasibility and effectiveness of the proposed algorithm, two modified test systems are used as case studies

  14. The Thermal Expansion Of Feldspars

    Science.gov (United States)

    Hovis, G. L.; Medford, A.; Conlon, M.

    2009-12-01

    Hovis and others (1) investigated the thermal expansion of natural and synthetic AlSi3 feldspars and demonstrated that the coefficient of thermal expansion (α) decreases significantly, and linearly, with increasing room-temperature volume (VRT). In all such feldspars, therefore, chemical expansion limits thermal expansion. The scope of this work now has been broadened to include plagioclase and Ba-K feldspar crystalline solutions. X-ray powder diffraction data have been collected between room temperature and 925 °C on six plagioclase specimens ranging in composition from anorthite to oligoclase. When combined with thermal expansion data for albite (2,3,4) a steep linear trend of α as a function of VRT emerges, reflecting how small changes in composition dramatically affect expansion behavior. The thermal expansion data for five synthetic Ba-K feldspars ranging in composition from 20 to 100 mole percent celsian, combined with data for pure K-feldspar (3,4), show α-VRT relationships similar in nature to the plagioclase series, but with a slope and intercept different from the latter. Taken as a group all Al2Si2 feldspars, including anorthite and celsian from the present study along with Sr- (5) and Pb-feldspar (6) from other workers, show very limited thermal expansion that, unlike AlSi3 feldspars, has little dependence on the divalent-ion (or M-) site occupant. This apparently is due to the necessitated alternation of Al and Si in the tetrahedral sites of these minerals (7), which in turn locks the tetrahedral framework and makes the M-site occupant nearly irrelevant to expansion behavior. Indeed, in feldspar series with coupled chemical substitution it is the change away from a 1:1 Al:Si ratio that gives feldspars greater freedom to expand. Overall, the relationships among α, chemical composition, and room-temperature volume provide useful predictive tools for estimating feldspar thermal expansion and give insight into the controls of expansion behavior in

  15. Solution of radial spin-1 field equation in Robertson-Walker space-time via Heun's equation

    International Nuclear Information System (INIS)

    Zecca, A.

    2010-01-01

    The spin-1 field equation is considered in Robertson-Walker spacetime. The problem of the solution of the separated radial equations, previously discussed in the flat space-time case, is solved also for both the closed and open curvature case. The radial equation is reduced to Heun's differential equation that recently has been widely reconsidered. It is shown that the solution of the present Heun equation does not fall into the class of polynomial-like or hypergeometric functions. Heun's operator results also non-factorisable. The properties follow from application of general theorems and power series expansion. In the positive curvature case of the universe a discrete energy spectrum of the system is found. The result follows by requiring a polynomial-like behaviour of at least one component of the spinor field. Developments and applications of the theory suggest further study of the solution of Heun's equation.

  16. Understanding the requirements of self-expandable stents for heart valve replacement: Radial force, hoop force and equilibrium.

    Science.gov (United States)

    Cabrera, María Sol; Oomens, Cees W J; Baaijens, Frank P T

    2017-04-01

    A proper interpretation of the forces developed during stent crimping and deployment is of paramount importance for a better understanding of the requirements for successful heart valve replacement. The present study combines experimental and computational methods to assess the performance of a nitinol stent for tissue-engineered heart valve implantation. To validate the stent model, the mechanical response to parallel plate compression and radial crimping was evaluated experimentally. Finite element simulations showed good agreement with the experimental findings. The computational models were further used to determine the hoop force on the stent and radial force on a rigid tool during crimping and self-expansion. In addition, stent deployment against ovine and human pulmonary arteries was simulated to determine the hoop force on the stent-artery system and the equilibrium diameter for different degrees of oversizing. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. An alternative approach to the management of reactive metals: tolerant cementitious systems

    International Nuclear Information System (INIS)

    Swift, P.; Cox, J.; Wise, M.; McKinney, J.; Rhodes, C.

    2015-01-01

    In recent years research has focused on preventing or minimising corrosion of reactive metals to ensure long-term waste package integrity. An alternative approach to the encapsulation of reactive metals is being explored. The approach will identify a cementitious-based encapsulating material that will allow corrosion of reactive metals to occur in a controlled and predictable manner, rather than seeking to limit or prevent the corrosion, whilst retaining waste package integrity. A low strength grout will be developed that will be 'tolerant' to the expansive forces generated by the corrosion products of reactive metals. Novel cementitious systems (e.g. foamed cements, rubber composite cements, cenosphere composite cements, lime mortars, bentonite cements etc.) that may be tolerant to potentially expansive waste products, such as reactive metals will be considered and assessed in a series of small-scale preliminary trials (compressive strength, porosity, permeability, pore solution pH, etc.)

  18. Crude oil pipeline expansion summary

    International Nuclear Information System (INIS)

    2005-02-01

    The Canadian Association of Petroleum Producers has been working with producers to address issues associated with the development of new pipeline capacity from western Canada. This document presents an assessment of the need for additional oil pipeline capacity given the changing mix of crude oil types and forecasted supply growth. It is of particular interest to crude oil producers and contributes to current available information for market participants. While detailed, the underlying analysis does not account for all the factors that may come into play when individual market participants make choices about which expansions they may support. The key focus is on the importance of timely expansion. It was emphasized that if pipeline expansions lags the crude supply growth, then the consequences would be both significant and unacceptable. Obstacles to timely expansion are also discussed. The report reviews the production and supply forecasts, the existing crude oil pipeline infrastructure, opportunities for new market development, requirements for new pipeline capacity and tolling options for pipeline development. tabs., figs., 1 appendix

  19. Asymptotic Expansions - Methods and Applications

    International Nuclear Information System (INIS)

    Harlander, R.

    1999-01-01

    Different viewpoints on the asymptotic expansion of Feynman diagrams are reviewed. The relations between the field theoretic and diagrammatic approaches are sketched. The focus is on problems with large masses or large external momenta. Several recent applications also for other limiting cases are touched upon. Finally, the pros and cons of the different approaches are briefly discussed. (author)

  20. Model of clinker capacity expansion

    CSIR Research Space (South Africa)

    Stylianides, T

    1998-10-01

    Full Text Available This paper describes a model which has been applied in practice to determine an optimal plan for clinker capacity expansion. The problem was formulated as an integer linear program aiming to determine the optimal number, size and location of kilns...

  1. The bootstrap and edgeworth expansion

    CERN Document Server

    Hall, Peter

    1992-01-01

    This monograph addresses two quite different topics, in the belief that each can shed light on the other. Firstly, it lays the foundation for a particular view of the bootstrap. Secondly, it gives an account of Edgeworth expansion. Chapter 1 is about the bootstrap, witih almost no mention of Edgeworth expansion; Chapter 2 is about Edgeworth expansion, with scarcely a word about the bootstrap; and Chapters 3 and 4 bring these two themes together, using Edgeworth expansion to explore and develop the properites of the bootstrap. The book is aimed a a graduate level audience who has some exposure to the methods of theoretical statistics. However, technical details are delayed until the last chapter (entitled "Details of Mathematical Rogour"), and so a mathematically able reader without knowledge of the rigorous theory of probability will have no trouble understanding the first four-fifths of the book. The book simultaneously fills two gaps in the literature; it provides a very readable graduate level account of t...

  2. On Fourier re-expansions

    OpenAIRE

    Liflyand, E.

    2012-01-01

    We study an extension to Fourier transforms of the old problem on absolute convergence of the re-expansion in the sine (cosine) Fourier series of an absolutely convergent cosine (sine) Fourier series. The results are obtained by revealing certain relations between the Fourier transforms and their Hilbert transforms.

  3. On persistently positively expansive maps

    Directory of Open Access Journals (Sweden)

    Alexander Arbieto

    2010-06-01

    Full Text Available In this paper, we prove that any C¹-persistently positively expansive map is expanding. This improves a result due to Sakai (Sakai 2004.Neste artigo, mostramos que todo mapa C¹-persistentemente positivamente expansivo e expansor. Isto melhora um resultado devido a Sakai (Sakai 2004.

  4. The expansion of electric power systems considering the operation reliability; Expansion de sistemas electricos considerando la securidad de servicio

    Energy Technology Data Exchange (ETDEWEB)

    Cortes, Marcelo A. [Universidad de Antofagasta (Chile). Dept. de Ingenieria Electrica; Moya A, Oscar [Chile Univ., Santiago (Chile). Dept. de Ingenieria Civil

    1997-12-31

    This publication describes a procedure based in an linear programming for the planning of the expansion of mediating term in power systems. The implicit alternatives for network expansion, whether power plants or transmission lines, are classified according to indexes of reinforcement. The indexes are gotten resulting shadow pricing upon resolving a problem of minimum cost of operation and outage. The network is subjected to the most probable contingencies and from these outputs the expected reinforcement results are obtained. The problem of the reactive power accounts for restrictions in line capacity and prior evaluation of A C power flux. Results obtained are used for methodology validation. (author) 12 refs., 1 fig., 3 tabs.; e-mail: mcortes at apolo.cc.uantof.cl.; osmoya at tamarugo.cec.uchile.cl

  5. Assessment of PWR safety with regard to disturbances due to reactivity changes

    International Nuclear Information System (INIS)

    Pernica, R.

    1980-01-01

    The steady state method is briefly described for reactivity disturbances assessment using steady state calculations for two sets of reactivity coefficients and four values of the thermal conductivity of the gap. The variations were processed of the limit values of reactivity being applied with the thermal conductivity of the gap between the fuel and the can. All calculations were performed for a reactor with four core zones exposed to different radial thermal stresses with different fuel element proportional stresses. The results are shown in graphs. (J.B.)

  6. Reactive power compensator

    Science.gov (United States)

    El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.; Chen, Mingliang; Andexler, George; Huang, Tony

    1992-01-01

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

  7. Reactive power compensator

    Energy Technology Data Exchange (ETDEWEB)

    El-Sharkawi, Mohamed A. (Renton, WA); Venkata, Subrahmanyam S. (Woodinville, WA); Chen, Mingliang (Kirkland, WA); Andexler, George (Everett, WA); Huang, Tony (Seattle, WA)

    1992-01-01

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

  8. RADIAL VELOCITY MONITORING OF KEPLER HEARTBEAT STARS

    Energy Technology Data Exchange (ETDEWEB)

    Shporer, Avi [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Fuller, Jim [TAPIR, Walter Burke Institute for Theoretical Physics, Mailcode 350-17, Caltech, Pasadena, CA 91125 (United States); Isaacson, Howard [Department of Astronomy, University of California, Berkeley CA 94720 (United States); Hambleton, Kelly; Prša, Andrej [Department of Astrophysics and Planetary Science, Villanova University, 800 East Lancaster Avenue, Villanova, PA 19085 (United States); Thompson, Susan E. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Kurtz, Donald W. [Jeremiah Horrocks Institute, University of Central Lancashire, Preston, PR1 2HE (United Kingdom); Howard, Andrew W. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); O’Leary, Ryan M. [JILA, University of Colorado and NIST, 440 UCB, Boulder, 80309-0440 (United States)

    2016-09-20

    Heartbeat stars (HB stars) are a class of eccentric binary stars with close periastron passages. The characteristic photometric HB signal evident in their light curves is produced by a combination of tidal distortion, heating, and Doppler boosting near orbital periastron. Many HB stars continue to oscillate after periastron and along the entire orbit, indicative of the tidal excitation of oscillation modes within one or both stars. These systems are among the most eccentric binaries known, and they constitute astrophysical laboratories for the study of tidal effects. We have undertaken a radial velocity (RV) monitoring campaign of Kepler HB stars in order to measure their orbits. We present our first results here, including a sample of 22 Kepler HB systems, where for 19 of them we obtained the Keplerian orbit and for 3 other systems we did not detect a statistically significant RV variability. Results presented here are based on 218 spectra obtained with the Keck/HIRES spectrograph during the 2015 Kepler observing season, and they have allowed us to obtain the largest sample of HB stars with orbits measured using a single instrument, which roughly doubles the number of HB stars with an RV measured orbit. The 19 systems measured here have orbital periods from 7 to 90 days and eccentricities from 0.2 to 0.9. We show that HB stars draw the upper envelope of the eccentricity–period distribution. Therefore, HB stars likely represent a population of stars currently undergoing high eccentricity migration via tidal orbital circularization, and they will allow for new tests of high eccentricity migration theories.

  9. Scaling laws for radial foil bearings

    Science.gov (United States)

    Honavara Prasad, Srikanth

    The effects of fluid pressurization, structural deformation of the compliant members and heat generation in foil bearings make the design and analysis of foil bearings very complicated. The complex fluid-structural-thermal interactions in foil bearings also make modeling efforts challenging because these phenomena are governed by highly non-linear partial differential equations. Consequently, comparison of various bearing designs require detailed calculation of the flow fields (velocities, pressures), bump deflections (structural compliance) and heat transfer phenomena (viscous dissipation in the fluid, frictional heating, temperature profile etc.,) resulting in extensive computational effort (time/hardware). To obviate rigorous computations and aid in feasibility assessments of foil bearings of various sizes, NASA developed the "rule of thumb" design guidelines for estimation of journal bearing load capacity. The guidelines are based on extensive experimental data. The goal of the current work is the development of scaling laws for radial foil bearings to establish an analytical "rule of thumb" for bearing clearance and bump stiffness. The use of scale invariant Reynolds equation and experimentally observed NASA "rule of thumb" yield scale factors which can be deduced from first principles. Power-law relationships between: a. Bearing clearance and bearing radius, and b. bump stiffness and bearing radius, are obtained. The clearance and bump stiffness values obtained from scaling laws are used as inputs for Orbit simulation to study various cases. As the clearance of the bearing reaches the dimensions of the material surface roughness, asperity contact breaks the fluid film which results in wear. Similarly, as the rotor diameter increases (requiring larger bearing diameters), the load capacity of the fluid film should increase to prevent dry rubbing. This imposes limits on the size of the rotor diameter and consequently bearing diameter. Therefore, this thesis aims

  10. RADIAL VELOCITY MONITORING OF KEPLER HEARTBEAT STARS

    International Nuclear Information System (INIS)

    Shporer, Avi; Fuller, Jim; Isaacson, Howard; Hambleton, Kelly; Prša, Andrej; Thompson, Susan E.; Kurtz, Donald W.; Howard, Andrew W.; O’Leary, Ryan M.

    2016-01-01

    Heartbeat stars (HB stars) are a class of eccentric binary stars with close periastron passages. The characteristic photometric HB signal evident in their light curves is produced by a combination of tidal distortion, heating, and Doppler boosting near orbital periastron. Many HB stars continue to oscillate after periastron and along the entire orbit, indicative of the tidal excitation of oscillation modes within one or both stars. These systems are among the most eccentric binaries known, and they constitute astrophysical laboratories for the study of tidal effects. We have undertaken a radial velocity (RV) monitoring campaign of Kepler HB stars in order to measure their orbits. We present our first results here, including a sample of 22 Kepler HB systems, where for 19 of them we obtained the Keplerian orbit and for 3 other systems we did not detect a statistically significant RV variability. Results presented here are based on 218 spectra obtained with the Keck/HIRES spectrograph during the 2015 Kepler observing season, and they have allowed us to obtain the largest sample of HB stars with orbits measured using a single instrument, which roughly doubles the number of HB stars with an RV measured orbit. The 19 systems measured here have orbital periods from 7 to 90 days and eccentricities from 0.2 to 0.9. We show that HB stars draw the upper envelope of the eccentricity–period distribution. Therefore, HB stars likely represent a population of stars currently undergoing high eccentricity migration via tidal orbital circularization, and they will allow for new tests of high eccentricity migration theories.

  11. Development of micro-scale axial and radial turbines for low-temperature heat source driven organic Rankine cycle

    International Nuclear Information System (INIS)

    Al Jubori, Ayad; Daabo, Ahmed; Al-Dadah, Raya K.; Mahmoud, Saad; Ennil, Ali Bahr

    2016-01-01

    Highlights: • One and three-dimensional analysis with real gas properties are integrated. • Micro axial and radial-inflow turbines configurations are investigated. • Five organic working fluids are considered. • The maximum total isentropic efficiency of radial-inflow turbine 83.85%. • The maximum ORC thermal efficiency based on radial-inflow turbine is 10.60%. - Abstract: Most studies on the organic Rankine cycle (ORC) focused on parametric studies and selection working fluids to maximize the performance of organic Rankine cycle but without attention for turbine design features which are crucial to achieving them. The rotational speed, expansion ratio, mass flow rate and turbine size have markedly effect on turbine performance. For this purpose organic Rankine cycle modeling, mean-line design and three-dimensional computational fluid dynamics analysis were integrated for both micro axial and radial-inflow turbines with five organic fluids (R141b, R1234yf, R245fa, n-butane and n-pentane) for realistic low-temperature heat source <100 °C like solar and geothermal energy. Three-dimensional simulation is performed using ANSYS"R"1"7-CFX where three-dimensional Reynolds-averaged Navier-Stokes equations are solved with k-omega shear stress transport turbulence model. Both configurations of turbines are designed at wide range of mass flow rate (0.1–0.5) kg/s for each working fluid. The results showed that n-pentane has the highest performance at all design conditions where the maximum total-to-total efficiency and power output of radial-inflow turbine are 83.85% and 8.893 kW respectively. The performance of the axial turbine was 83.48% total-to-total efficiency and 8.507 kW power output. The maximum overall size of axial turbine was 64.685 mm compared with 70.97 mm for radial-inflow turbine. R245fa has the lowest overall size for all cases. The organic Rankine cycle thermal efficiency was about 10.60% with radial-inflow turbine and 10.14% with axial turbine

  12. Digital reactivity meter

    International Nuclear Information System (INIS)

    Copie, M.; Valantic, B.

    1978-01-01

    Digital reactivity meters (DRM) are mostly used as measuring instruments, e.g. for calibration of control rods, and there are only a few cases of their incorporation into the control systems of the reactors. To move in this direction there is more development work needed. First of all, fast algorithms are needed for inverse kinetics equations to relieve the computer for more important tasks of reactor model solving in real time. The next problem, currently under investigation, is the incorporation of the reactor thermal-hydraulic model into the DRM so that it can be used in the power range. Such an extension of DHM allows presentation not only of the instantaneous reactivity of the system, but also the inserted reactivity can be estimated from the temperature reactivity feed-backs. One of the applications of this concept is the anomalous digital reactivity monitor (ADRN) as part of the reactor protection system. As a solution of the first problem, a fast algorithm for solving the inverse kinetics equations has been implemented in the off-line program RODCAL on CDC 1700 computer and tested for its accuracy by performing different control rod calibrations on the reactor TRIGA

  13. Radial head fracture associated with posterior interosseous nerve injury

    Directory of Open Access Journals (Sweden)

    Bernardo Barcellos Terra

    Full Text Available ABSTRACT Fractures of the radial head and radial neck correspond to 1.7-5.4% of all fractures and approximately 30% may present associated injuries. In the literature, there are few reports of radial head fracture with posterior interosseous nerve injury. This study aimed to report a case of radial head fracture associated with posterior interosseous nerve injury. CASE REPORT: A male patient, aged 42 years, sought medical care after falling from a skateboard. The patient related pain and limitation of movement in the right elbow and difficulty to extend the fingers of the right hand. During physical examination, thumb and fingers extension deficit was observed. The wrist extension showed a slight radial deviation. After imaging, it became evident that the patient had a fracture of the radial head that was classified as grade III in the Mason classification. The patient underwent fracture fixation; at the first postoperative day, thumb and fingers extension was observed. Although rare, posterior interosseous nerve branch injury may be associated with radial head fractures. In the present case, the authors believe that neuropraxia occurred as a result of the fracture hematoma and edema.

  14. Influence of external source location in the reactivity calculation

    International Nuclear Information System (INIS)

    Silva, Adilson Costa da; Silva, Fernando Carvalho da; Martinez, Aquilino Senra

    2011-01-01

    We used the neutron diffusion equation with external neutron sources, in cartesian geometry and the two groups of energy, to verify the influence of external neutron source locations in the reactivity calculation. For this, a coarse mesh finite difference method was developed for the adjoint flux calculation and simplifies reactivity calculation in PWR type reactor, which uses the output of the nodal expansion method. The results were obtained for different locations on the two-dimensional plane, as well as for different types of fuel elements in the reactor core. (author)

  15. Influence of external source location in the reactivity calculation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Adilson Costa da; Silva, Fernando Carvalho da; Martinez, Aquilino Senra, E-mail: asilva@con.ufrj.b, E-mail: fernando@con.ufrj.b, E-mail: Aquilino@lmp.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2011-07-01

    We used the neutron diffusion equation with external neutron sources, in cartesian geometry and the two groups of energy, to verify the influence of external neutron source locations in the reactivity calculation. For this, a coarse mesh finite difference method was developed for the adjoint flux calculation and simplifies reactivity calculation in PWR type reactor, which uses the output of the nodal expansion method. The results were obtained for different locations on the two-dimensional plane, as well as for different types of fuel elements in the reactor core. (author)

  16. Evaluation of the radial design of fuel cells in an operation cycle of a BWR reactor; Evaluacion del diseno radial de celdas de combustible en un ciclo de operacion de un reactor BWR

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez C, J.; Martin del Campo M, C. [Laboratorio de Analisis en Ingenieria de Reactores Nucleares, Facultad de Ingenieria, UNAM, Paseo Cuauhnahuac 8532, Jiutepec, Morelos (Mexico)]. e-mail: jgco@ver.megared.net.mx

    2003-07-01

    This work is continuation of one previous in the one that the application of the optimization technique called Tabu search to the radial design of fuel cells of boiling water reactors (BWR, Boiling Water Reactor) is presented. The objective function used in the optimization process only include neutron parameters (k-infinite and peak of radial power) considering the cell at infinite media. It was obtained to reduce the cell average enrichment completing the characteristics of reactivity of an original cell. The objective of the present work is to validate the objective function that was used for the radial design of the fuel cell (test cell), analyzing the operation of a one cycle of the reactor in which fuels have been fresh recharged that contain an axial area with the nuclear database of the cell designed instead of the original cell. For it is simulated it with Cm-Presto the cycle 10 of the reactor operation of the Unit 1 of the Nuclear Power station of Laguna Verde (U1-CNLV). For the cycle evaluation its were applied so much the simulation with the Haling strategy, as the simulation of the one cycle with control rod patterns and they were evaluated the energy generation and several power limits and reactivity that are used as design parameters in fuel reloads of BWR reactors. The results at level of an operation cycle of the reactor, show that the objective function used in the optimization and radial design of the cell is adequate and that it can induce to one good use of the fuel. (Author)

  17. Stellar Angular Momentum Distributions and Preferential Radial Migration

    Science.gov (United States)

    Wyse, Rosemary; Daniel, Kathryne J.

    2018-04-01

    I will present some results from our recent investigations into the efficiency of radial migration in stellar disks of differing angular momentum distributions, within a given adopted 2D spiral disk potential. We apply to our models an analytic criterion that determines whether or not individual stars are in orbits that could lead to radial migration around the corotation resonance. We couch our results in terms of the local stellar velocity dispersion and find that the fraction of stars that could migrate radially decreases as the velocity dispersion increases. I will discuss implications and comparisons with the results of other approaches.

  18. Research on Radial Vibration of a Circular Plate

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2016-01-01

    Full Text Available Radial vibration of the circular plate is presented using wave propagation approach and classical method containing Bessel solution and Hankel solution for calculating the natural frequency theoretically. In cylindrical coordinate system, in order to obtain natural frequency, propagation and reflection matrices are deduced at the boundaries of free-free, fixed-fixed, and fixed-free using wave propagation approach. Furthermore, radial phononic crystal is constructed by connecting two materials periodically for the analysis of band phenomenon. Also, Finite Element Simulation (FEM is adopted to verify the theoretical results. Finally, the radial and piezoelectric effects on the band are also discussed.

  19. Evolution of radial profiles in regular Lemaitre-Tolman-Bondi dust models

    International Nuclear Information System (INIS)

    Sussman, Roberto A

    2010-01-01

    We undertake a comprehensive and rigorous analytic study of the evolution of radial profiles of covariant scalars in regular LemaItre-Tolman-Bondi (LTB) dust models. We consider specifically the phenomenon of 'profile inversions' in which an initial clump profile of density, spatial curvature or the expansion scalar might evolve into a void profile (and vice versa). Previous work in the literature on models with density void profiles and/or allowing for density profile inversions is given full generalization, with some erroneous results corrected. We prove rigorously that if an evolution without shell crossings is assumed, then only the 'clump to void' inversion can occur in density profiles, and only in hyperbolic models or regions with negative spatial curvature. The profiles of spatial curvature follow similar patterns as those of the density, with 'clump to void' inversions only possible for hyperbolic models or regions. However, profiles of the expansion scalar are less restrictive, with profile inversions necessarily taking place in elliptic models. We also examine radial profiles in special LTB configurations: closed elliptic models, models with a simultaneous big bang singularity, as well as a locally collapsing elliptic region surrounded by an expanding hyperbolic background. The general analytic statements that we obtain allow for setting up the right initial conditions to construct fully regular LTB models with any specific qualitative requirements for the profiles of all scalars and their time evolution. The results presented can be very useful in guiding future numerical work on these models and in revising previous analytic work on all their applications.

  20. Transport of secondary electrons and reactive species in ion tracks

    Science.gov (United States)

    Surdutovich, Eugene; Solov'yov, Andrey V.

    2015-08-01

    The transport of reactive species brought about by ions traversing tissue-like medium is analysed analytically. Secondary electrons ejected by ions are capable of ionizing other molecules; the transport of these generations of electrons is studied using the random walk approximation until these electrons remain ballistic. Then, the distribution of solvated electrons produced as a result of interaction of low-energy electrons with water molecules is obtained. The radial distribution of energy loss by ions and secondary electrons to the medium yields the initial radial dose distribution, which can be used as initial conditions for the predicted shock waves. The formation, diffusion, and chemical evolution of hydroxyl radicals in liquid water are studied as well. COST Action Nano-IBCT: Nano-scale Processes Behind Ion-Beam Cancer Therapy.

  1. Axial and Radial Forces of Cross-Bridges Depend on Lattice Spacing

    Science.gov (United States)

    Williams, C. David; Regnier, Michael; Daniel, Thomas L.

    2010-01-01

    Nearly all mechanochemical models of the cross-bridge treat myosin as a simple linear spring arranged parallel to the contractile filaments. These single-spring models cannot account for the radial force that muscle generates (orthogonal to the long axis of the myofilaments) or the effects of changes in filament lattice spacing. We describe a more complex myosin cross-bridge model that uses multiple springs to replicate myosin's force-generating power stroke and account for the effects of lattice spacing and radial force. The four springs which comprise this model (the 4sXB) correspond to the mechanically relevant portions of myosin's structure. As occurs in vivo, the 4sXB's state-transition kinetics and force-production dynamics vary with lattice spacing. Additionally, we describe a simpler two-spring cross-bridge (2sXB) model which produces results similar to those of the 4sXB model. Unlike the 4sXB model, the 2sXB model requires no iterative techniques, making it more computationally efficient. The rate at which both multi-spring cross-bridges bind and generate force decreases as lattice spacing grows. The axial force generated by each cross-bridge as it undergoes a power stroke increases as lattice spacing grows. The radial force that a cross-bridge produces as it undergoes a power stroke varies from expansive to compressive as lattice spacing increases. Importantly, these results mirror those for intact, contracting muscle force production. PMID:21152002

  2. Extracting kinetic freeze-out temperature and radial flow velocity from an improved Tsallis distribution

    Energy Technology Data Exchange (ETDEWEB)

    Lao, Hai-Ling; Liu, Fu-Hu [Shanxi University, Institute of Theoretical Physics, Shanxi (China); Lacey, Roy A. [Stony Brook University, Departments of Chemistry and Physics, Stony Brook, NY (United States)

    2017-03-15

    We analyze the transverse-momentum (p{sub T}) spectra of identified particles (π{sup ±}, K{sup ±}, p, and anti p) produced in gold-gold (Au-Au) and lead-lead (Pb-Pb) collisions over a √(s{sub NN}) (center-of-mass energy per nucleon pair) range from 14.5 GeV (one of the Relativistic Heavy Ion Collider (RHIC) energies) to 2.76 TeV (one of the Large Hadron Collider (LHC) energies). For the spectra with a narrow p{sub T} range, an improved Tsallis distribution which is in fact the Tsallis distribution with radial flow is used. For the spectra with a wide p{sub T} range, a superposition of the improved Tsallis distribution and an inverse power law is used. Both the extracted kinetic freeze-out temperature (T{sub 0}) and radial flow velocity (β{sub T}) increase with the increase of √(s{sub NN}), which indicates a higher excitation and larger expansion of the interesting system at the LHC. Both the values of T{sub 0} and β{sub T} in central collisions are slightly larger than those in peripheral collisions, and they are independent of isospin and slightly dependent on mass. (orig.)

  3. Kinetic transport properties of a bumpy torus with finite radial ambipolar field

    International Nuclear Information System (INIS)

    Spong, D.A.; Harris, E.G.; Hedrick, C.L.

    1978-04-01

    Bumpy torus neoclassical transport coefficients have been calculted including finite values of the radial ambipolar field. These are obtained by solving a bounce-averaged drift kinetic equation in a local approximation for perturbations in the distribution function (away from a stationary Maxwellian) caused by toroidicity and radial gradients in plasma density, temperature, and potential. Particle and energy fluxes along with the associated transport coefficients are then calculated by taking appropriate moments of the distribution function. Particle orbits are treated by breaking them up into a vertical drift component (due to toroidicity) and a theta precessional drift (as a result of Vector E x Vector B and drifts due to the bumpy toroidal field). The kinetic equation has been solved using both a functional expansion method and finite difference techniques [Alternating-Direction-Implicit (ADI)]. The resulting transport coefficients exhibit a strong dependence on the ambipolar electric field and plasma collisionality. In the large electric field limit, our results are in close agreement with the earlier work of Kovrizhnykh

  4. Exponential Expansion in Evolutionary Economics

    DEFF Research Database (Denmark)

    Frederiksen, Peter; Jagtfelt, Tue

    2013-01-01

    This article attempts to solve current problems of conceptual fragmentation within the field of evolutionary economics. One of the problems, as noted by a number of observers, is that the field suffers from an assemblage of fragmented and scattered concepts (Boschma and Martin 2010). A solution...... to this problem is proposed in the form of a model of exponential expansion. The model outlines the overall structure and function of the economy as exponential expansion. The pictographic model describes four axiomatic concepts and their exponential nature. The interactive, directional, emerging and expanding...... concepts are described in detail. Taken together it provides the rudimentary aspects of an economic system within an analytical perspective. It is argued that the main dynamic processes of the evolutionary perspective can be reduced to these four concepts. The model and concepts are evaluated in the light...

  5. Production expansion continues to accelerate

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that Saudi Arabian Oil Co. (Saudi Aramco) is continuing its accelerated Crude Oil Expansion Program initiated in 1989 that aims at achieving a 10 million bpd productive capacity by 1995. In addition to major engineering, construction and renovation work related to production expansion, Saudi Aramco drilling and workover operations have been markedly expanded. Since January 1991, rig activity has doubled. As an indication of aging of Saudi production, projects include modernizing current injection water treatment facilities, installing a new seawater injection plant on the Persian Gulf, installing dewatering facilities in a number of locations and installing a pilot gas lift project. In addition, equipment orders indicate the new discoveries south of Riyadh may also need the assistance of water injection from inception of production

  6. Shrub expansion in SW Greenland

    DEFF Research Database (Denmark)

    Jørgensen, Rasmus Halfdan

    Arctic regions have experienced higher temperatures in recent decades, and the warming trend is projected to continue in the coming years. Arctic ecosystems are considered to be particularly vulnerable to climate change. Expansion of shrubs has been observed widely in tundra areas across the Arctic......, and has a range of ecosystem effects where it occurs. Shrub expansion has to a large extend been attributed to increasing temperatures over the past century, while grazing and human disturbance have received less attention. Alnus viridis ssp. crispa is a common arctic species that contributes...... to increasing shrub cover. Despite this, there is only limited experimental evidence that growth of the species responds to warming. Plant populations in fragmented and isolated locations could face problems adapting to a warming climate due to limited genetic variation and restricted migration from southern...

  7. The contribution of CXCL12-expressing radial glia cells to neuro-vascular patterning during human cerebral cortex development

    Directory of Open Access Journals (Sweden)

    Mariella eErrede

    2014-10-01

    Full Text Available This study was conducted on human developing brain by laser confocal and transmission electron microscopy to make a detailed analysis of important features of blood-brain barrier microvessels and possible control mechanisms of vessel growth and differentiation during cerebral cortex vascularization. The blood-brain barrier status of cortex microvessels was examined at a defined stage of cortex development, at the end of neuroblast waves of migration and before cortex lamination, with blood-brain barrier-endothelial cell markers, namely tight junction proteins (occludin and claudin-5 and influx and efflux transporters (Glut-1 and P-glycoprotein, the latter supporting evidence for functional effectiveness of the fetal blood-brain barrier. According to the well-known roles of astroglia cells on microvessel growth and differentiation, the early composition of astroglia/endothelial cell relationships was analysed by detecting the appropriate astroglia, endothelial, and pericyte markers. GFAP, chemokine CXCL12, and connexin 43 (Cx43 were utilized as markers of radial glia cells, CD105 (endoglin as a marker of angiogenically activated endothelial cells, and proteoglycan NG2 as a marker of immature pericytes. Immunolabeling for CXCL12 showed the highest level of the ligand in radial glial fibres in contact with the growing cortex microvessels. These specialized contacts, recognizable on both perforating radial vessels and growing collaterals, appeared as CXCL12-reactive en passant, symmetrical and asymmetrical vessel-specific RG fibre swellings. At the highest confocal resolution, these RG varicosities showed a CXCL12-reactive dot-like content whose microvesicular nature was confirmed by ultrastructural observations. A further analysis of radial glial varicosities reveals colocalization of CXCL12 with connexin Cx43, which is possibly implicated in vessel-specific chemokine signalling.

  8. RELIABILITY OF LENTICULAR EXPANSION COMPENSATORS

    Directory of Open Access Journals (Sweden)

    Gabriel BURLACU,

    2011-11-01

    Full Text Available Axial lenticular compensators are made to take over the longitudinal heat expansion, shock , vibration and noise, made elastic connections for piping systems. In order to have a long life for installations it is necessary that all elements, including lenticular compensators, have a good reliability. This desire can be did by technology of manufactoring and assembly of compensators, the material for lenses and by maintenance.of compensator

  9. Granular Corneal Dystrophy Manifesting after Radial Keratotomy

    Directory of Open Access Journals (Sweden)

    Sepehr Feizi

    2008-12-01

    Full Text Available

    PURPOSE: To report manifestation of granular corneal dystrophy after radial keratotomy (RK. CASE REPORT: A 32-year-old man presented with white radial lines in both corneas. He had undergone uncomplicated RK in both eyes 8 years ago. Preoperative refraction had been OD: -3.5 -0.75@180 and OS: -3.0 -0.5@175. Uncorrected visual acuity was OD: 8/10 and OS: 7/10; best corrected visual acuity was 9/10 in both eyes with OD: -0.5 -0.5@60 and OS: -0.75 -0.5@80. Slit lamp examination revealed discrete well-demarcated whitish lesions with clear intervening stroma in the central anterior cornea consistent with granular dystrophy. Similar opacities were present within the RK incisions. CONCLUSION: Granular dystrophy deposits may appear within RK incisions besides other previously reported locations.

  1. The iodine reactivity

    International Nuclear Information System (INIS)

    2003-01-01

    The iodine is an important element because it has long life isotopes (such as iodine 129) and a great mobility in natural media. Iodine presents a complex chemistry because of its volatility and its strong redox reactivity. The S.E.C.R. works to better understand the reactivity of this element in different natural, industrial or biological environments. It plays a part in thermochemical sites as a possible way of hydrogen formation. This seminar gives some aspects relative to the chemical reactivity of iodine, since its thermochemistry in the I/S cycles to produce hydrogen to its reactivity in the natural medium and its potential radiological impact. This document includes 4 presentations transparencies) dealing with: the 129 I cycle rejected in the low radioactive gaseous and liquid effluents of the La Hague reprocessing plant (C. Frechou); a bibliographic review of iodine retention in soils (F. Bazer-Bachi); the hydrogen production and the iodine/sulfur thermochemical cycle (role of iodine in the process); and the direct characterization by electro-spray ionization mass spectroscopy of iodine fixation by fulvic acids (P. Reiller, B. Amekraz, C. Moulin, V. Moulin)

  2. Upscaling of reactive flows

    NARCIS (Netherlands)

    Kumar, K.

    2012-01-01

    The thesis deals with the upscaling of reactive flows in complex geometry. The reactions which may include deposition or dissolution take place at a part of the boundary and depending on the size of the reaction domain, the changes in the pore structure that are due to the deposition process may or

  3. Effect of Strain on the Reactivity of Metal Surfaces

    DEFF Research Database (Denmark)

    Mavrikakis, Manos; Hammer, Bjørk; Nørskov, Jens Kehlet

    1998-01-01

    Self-consistent density functional calculations for the adsorption of O and CO, and the dissociation of CO on strained and unstrained Ru(0001) surfaces are used to show how strained metal surfaces have chemical properties that are significantly different from those of unstrained surfaces. Surface...... reactivity increases with lattice expansion, following a concurrent up-shift of the metal d states. Consequences for the catalytic activity of thin metal overlayers are discussed....

  4. Endoscopic versus open radial artery harvest and mammario-radial versus aorto-radial grafting in patients undergoing coronary artery bypass surgery

    DEFF Research Database (Denmark)

    Carranza, Christian L; Ballegaard, Martin; Werner, Mads U

    2014-01-01

    the postoperative complications will be registered, and we will evaluate muscular function, scar appearance, vascular supply to the hand, and the graft patency including the patency of the central radial artery anastomosis. A patency evaluation by multi-slice computer tomography will be done at one year...... to aorto-radial revascularisation techniques but this objective is exploratory. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01848886.Danish Ethics committee number: H-3-2012-116.Danish Data Protection Agency: 2007-58-0015/jr.n:30-0838....

  5. Intravascular Papillary Endothelial Hyperplasia (Masson’s Tumor) of the Radial Artery: A Case Report

    International Nuclear Information System (INIS)

    Stark, Christopher; Olsen, Daniel; Morris, Christopher; Bertges, Daniel; Najarian, Kenneth

    2016-01-01

    Intravascular papillary endothelial hyperplasia (IPEH), often referred to as Masson’s tumor, is a benign non-neoplastic vascular lesion of the skin and subcutaneous tissues. Although it is rare, knowledge of the existence of IPEH is important as it can mimic other benign and malignant tumors, most notably angiosarcoma. IPEH remains an incompletely understood entity; however, most consider it to be the result of reactive endothelial proliferation following thrombus formation within a vessel, vascular malformation, or adjacent to a vessel. In this article, we report a case of IPEH arising within an arteriovenous malformation of the radial artery and present accompanying multimodality imaging and pathology figures. We will also describe the clinical presentation, pathophysiology, histology, imaging features, and management of IPEH.

  6. Intravascular Papillary Endothelial Hyperplasia (Masson’s Tumor) of the Radial Artery: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Stark, Christopher, E-mail: Christopher.stark@uvmhealth.org [University of Vermont Medical Center, Department of Radiology (United States); Olsen, Daniel [Mayo Clinic, Department of Pathology (United States); Morris, Christopher [University of Vermont Medical Center, Department of Radiology (United States); Bertges, Daniel [University of Vermont Medical Center, Department of Surgery (United States); Najarian, Kenneth [University of Vermont Medical Center, Department of Radiology (United States)

    2016-11-15

    Intravascular papillary endothelial hyperplasia (IPEH), often referred to as Masson’s tumor, is a benign non-neoplastic vascular lesion of the skin and subcutaneous tissues. Although it is rare, knowledge of the existence of IPEH is important as it can mimic other benign and malignant tumors, most notably angiosarcoma. IPEH remains an incompletely understood entity; however, most consider it to be the result of reactive endothelial proliferation following thrombus formation within a vessel, vascular malformation, or adjacent to a vessel. In this article, we report a case of IPEH arising within an arteriovenous malformation of the radial artery and present accompanying multimodality imaging and pathology figures. We will also describe the clinical presentation, pathophysiology, histology, imaging features, and management of IPEH.

  7. Computing closest saddle node bifurcations in a radial system via conic programming

    Energy Technology Data Exchange (ETDEWEB)

    Jabr, R.A. [Electrical, Computer and Communication Engineering Department, Notre Dame University, P.O. Box 72, Zouk Mikhael, Zouk Mosbeh (Lebanon); Pal, B.C. [Department of Electrical and Electronic Engineering, Imperial College London, SW7 2BT (United Kingdom)

    2009-07-15

    This paper considers the problem of computing the loading limits in a radial system which are (i) locally closest to current operating load powers and (ii) at which saddle node bifurcation occurs. The procedure is based on a known technique which requires iterating between two computational steps until convergence. In essence, step 1 produces a vector normal to the real and/or reactive load solution space boundary, whereas step 2 computes the bifurcation point along that vector. The paper shows that each of the above computational steps can be formulated as a second-order cone program for which polynomial time interior-point methods and efficient implementations exist. The proposed conic programming approach is used to compute the closest bifurcation points and the corresponding worst case load power margins of eleven different distribution systems. The approach is validated graphically and the existence of multiple load power margins is investigated. (author)

  8. Anterior transposition of the radial nerve--a cadaveric study.

    Science.gov (United States)

    Yakkanti, Madhusudhan R; Roberts, Craig S; Murphy, Joshua; Acland, Robert D

    2008-01-01

    The radial nerve is at risk during the posterior plating of the humerus. The purpose of this anatomic study was to assess the extent of radial nerve dissection required for anterior transposition through the fracture site (transfracture anterior transposition). A cadaver study was conducted approaching the humerus by a posterior midline incision. The extent of dissection of the nerve necessary for plate fixation of the humerus fracture was measured. An osteotomy was created to model a humeral shaft fracture at the spiral groove (OTA classification 12-A2, 12-A3). The radial nerve was then transposed anterior to the humeral shaft through the fracture site. The additional dissection of the radial nerve and the extent of release of soft tissue from the humerus shaft to achieve the transposition were measured. Plating required a dissection of the radial nerve 1.78 cm proximal and 2.13 cm distal to the spiral groove. Transfracture anterior transposition of the radial nerve required an average dissection of 2.24 cm proximal and 2.68 cm distal to the spiral groove. The lateral intermuscular septum had to be released for 2.21 cm on the distal fragment to maintain laxity of the transposed nerve. Transfracture anterior transposition of the radial nerve before plating is feasible with dissection proximal and distal to the spiral groove and elevation of the lateral intermuscular septum. Potential clinical advantages of this technique include enhanced fracture site visualization, application of broader plates, and protection of the radial nerve during the internal fixation.

  9. Radial-piston pump for drive of test machines

    Science.gov (United States)

    Nizhegorodov, A. I.; Gavrilin, A. N.; Moyzes, B. B.; Cherkasov, A. I.; Zharkevich, O. M.; Zhetessova, G. S.; Savelyeva, N. A.

    2018-01-01

    The article reviews the development of radial-piston pump with phase control and alternating-flow mode for seismic-testing platforms and other test machines. The prospects for use of the developed device are proved. It is noted that the method of frequency modulation with the detection of the natural frequencies is easily realized by using the radial-piston pump. The prospects of further research are given proof.

  10. Radially Polarized Conical Beam from an Embedded Etched Fiber

    OpenAIRE

    Kalaidji , D.; Spajer , M.; Marthouret , N.; Grosjean , T.

    2009-01-01

    International audience; We propose a method for producing a conical beam based on the lateral refraction of the TM01 mode from a two-mode fiber after chemical etching of the cladding, and for controlling its radial polarization. The whole power of the guided mode is transferred to the refracted beam with low diffraction. Polarization control by a series of azimuthal detectors and a stress controller affords the transmission of a stabilized radial polarization through an optical fiber. A solid...

  11. Luxation of the radial carpal bone in a cat

    International Nuclear Information System (INIS)

    Pitcher, G.D.C.

    1996-01-01

    A case of radial carpal bone luxation in the cat and its management is described. Open reduction was performed and surgically maintained, in combination with repair of rupture of the short radial collateral ligament and joint capsule. The carpus was supported for one month following surgery by application of transarticular external fixation. Four months after treatment the cat was sound, despite evidence of degenerative joint disease. The mechanism of luxation appears to be analogous to that seen in the dog

  12. Introducing radiality constraints in capacitated location-routing problems

    Directory of Open Access Journals (Sweden)

    Eliana Mirledy Toro Ocampo

    2017-03-01

    Full Text Available In this paper, we introduce a unified mathematical formulation for the Capacitated Vehicle Routing Problem (CVRP and for the Capacitated Location Routing Problem (CLRP, adopting radiality constraints in order to guarantee valid routes and eliminate subtours. This idea is inspired by formulations already employed in electric power distribution networks, which requires a radial topology in its operation. The results show that the proposed formulation greatly improves the convergence of the solver.

  13. Measurement of distribution coefficients using a radial injection dual-tracer test

    International Nuclear Information System (INIS)

    Pickens, J.F.; Jackson, R.E.; Inch, K.J.; Merritt, W.F.

    1981-01-01

    The dispersive and adsorptive properties of a sandy aquifer were evaluated by using a radial injection dual-tracer test with 131 I as the nonreactive tracer and 85 Sr as the reactive tracer. The tracer migration was monitored by using multilevel point-sampling devices located at various radial distances and depths. Nonequilibrium physical and chemical adsorption effects for 85 Sr were treated as a spreading or dispersion mechanism in the breakthrough curve analysis. The resulting effective dispersivity values for 85 Sr were typically a factor of 2 to 5 larger than those obtained for 131 I. The distribution coefficient (K/sub d//sup Sr/) values obtained from analysis of the breakthrough curves at three depths and two radial distances ranged from 2.6 to 4.5 ml/g. These compare favorably with values obtained by separation of fluids from solids in sediment cores, by batch experiments on core sediments and by analysis of a 25-year-old radioactive waste plume in another part of the same aquifer. Correlations of adsorbed 85 Sr radioactivity with grain size fractions demonstrated preferential adsorption to the coarsest fraction and to the finest fraction. The relative amounts of electrostatically and specifically adsorbed 85 Sr on the aquifer sediments were determined with desorption experiments on core sediments using selective chemical extractants. The withdrawal phase breakthrough curves for the well, obtained immediately following the injection phase, showed essentially full tracer recoveries for both 131 I and 85 Sr. Relatively slow desorption of 85 Sr provided further indication of the nonequilibrium nature of the adsorption-desorption phenomena

  14. A Power Series Expansion and Its Applications

    Science.gov (United States)

    Chen, Hongwei

    2006-01-01

    Using the power series solution of a differential equation and the computation of a parametric integral, two elementary proofs are given for the power series expansion of (arcsin x)[squared], as well as some applications of this expansion.

  15. Enhanced thermal expansion control rod drive lines for improving passive safety of fast reactors

    International Nuclear Information System (INIS)

    Edelmann, M.; Baumann, W.; Kuechle, M.; Kussmaul, G.; Vaeth, W.; Bertram, A.

    1992-01-01

    The paper presents a device for increasing the thermal expansion effect of control rod drive lines on negative reactivity feedback in fast reactors. The enhanced thermal expansion of this device can be utilized for both passive rod drop and forced insertion of absorbers in unprotected transients, e.g. ULOF. In this way the reactor is automatically brought into a permanently subcritical state and temperatures are kept well below the boiling point of the coolant. A prototype of such a device called ATHENa (German: Shut-down by THermal Expansion of Na) is presently under construction and will be tested. The paper presents the principle, design features and thermal properties of ATHENs as well as results of reactor dynamics calculations of ULOF's for EFR with enhanced thermal expansion control rod drive lines. (author)

  16. Illumination Profile & Dispersion Variation Effects on Radial Velocity Measurements

    Science.gov (United States)

    Grieves, Nolan; Ge, Jian; Thomas, Neil B.; Ma, Bo; Li, Rui; SDSS-III

    2015-01-01

    The Multi-object APO Radial-Velocity Exoplanet Large-Area Survey (MARVELS) measures radial velocities using a fiber-fed dispersed fixed-delay interferometer (DFDI) with a moderate dispersion spectrograph. This setup allows a unique insight into the 2D illumination profile from the fiber on to the dispersion grating. Illumination profile investigations show large changes in the profile over time and fiber location. These profile changes are correlated with dispersion changes and long-term radial velocity offsets, a major problem within the MARVELS radial velocity data. Characterizing illumination profiles creates a method to both detect and correct radial velocity offsets, allowing for better planet detection. Here we report our early results from this study including improvement of radial velocity data points from detected giant planet candidates. We also report an illumination profile experiment conducted at the Kitt Peak National Observatory using the EXPERT instrument, which has a DFDI mode similar to MARVELS. Using profile controlling octagonal-shaped fibers, long term offsets over a 3 month time period were reduced from ~50 m/s to within the photon limit of ~4 m/s.

  17. Channeling of protons through radial deformed carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Borka Jovanović, V., E-mail: vborka@vinca.rs [Atomic Physics Laboratory (040), Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Borka, D. [Atomic Physics Laboratory (040), Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Galijaš, S.M.D. [Faculty of Physics, University of Belgrade, P.O. Box 368, 11001 Belgrade (Serbia)

    2017-05-18

    Highlights: • For the first time we presented theoretically obtained distributions of channeled protons with radially deformed SWNT. • Our findings indicate that influence of the radial deformation is very strong and it should not be omitted in simulations. • We show that the spatial and angular distributions depend strongly of level of radial deformation of nanotube. • Our obtained results can be compared with measured distributions to reveal the presence of various types of defects in SWNT. - Abstract: In this paper we have presented a theoretical investigation of the channeling of 1 GeV protons with the radial deformed (10, 0) single-wall carbon nanotubes (SWNTs). We have calculated channeling potential within the deformed nanotubes. For the first time we presented theoretically obtained spatial and angular distributions of channeled protons with radially deformed SWNT. We used a Monte Carlo (MC) simulation technique. We show that the spatial and angular distributions depend strongly of level of radial deformation of nanotube. These results may be useful for nanotube characterization and production and guiding of nanosized ion beams.

  18. Heuristic for solving capacitor allocation problems in electric energy radial distribution networks

    Directory of Open Access Journals (Sweden)

    Maria A. Biagio

    2012-04-01

    Full Text Available The goal of the capacitor allocation problem in radial distribution networks is to minimize technical losses with consequential positive impacts on economic and environmental areas. The main objective is to define the size and location of the capacitors while considering load variations in a given horizon. The mathematical formulation for this planning problem is given by an integer nonlinear mathematical programming model that demands great computational effort to be solved. With the goal of solving this problem, this paper proposes a methodology that is composed of heuristics and Tabu Search procedures. The methodology presented explores network system characteristics of the network system reactive loads for identifying regions where procedures of local and intensive searches should be performed. A description of the proposed methodology and an analysis of computational results obtained which are based on several test systems including actual systems are presented. The solutions reached are as good as or better than those indicated by well referenced methodologies. The technique proposed is simple in its use and does not require calibrating an excessive amount of parameters, making it an attractive alternative for companies involved in the planning of radial distribution networks.

  19. Pathologic bone tissues in a Turkey vulture and a nonavian dinosaur: implications for interpreting endosteal bone and radial fibrolamellar bone in fossil dinosaurs.

    Science.gov (United States)

    Chinsamy, Anusuya; Tumarkin-Deratzian, Allison

    2009-09-01

    We report on similar pathological bone microstructure in an extant turkey vulture (Cathartes aura) and a nonavian dinosaur from Transylvania. Both these individuals exhibit distinctive periosteal reactive bone deposition accompanied by endosteal bone deposits in the medullary cavity. Our findings have direct implications on the two novel bone tissues recently described among nonavian dinosaurs, radial fibrolamellar bone tissue and medullary bone tissue. On the basis of the observed morphology of the periosteal reactive bone in the turkey vulture and the Transylvanian dinosaur, we propose that the radial fibrolamellar bone tissues observed in mature dinosaurs may have had a pathological origin. Our analysis also shows that on the basis of origin, location, and morphology, pathologically derived endosteal bone tissue can be similar to medullary bone tissues described in nonavian dinosaurs. As such, we caution the interpretation of all endosteally derived bone tissue as homologous to avian medullary bone. (c) 2009 Wiley-Liss, Inc.

  20. Reactive-brittle dynamics in peridotite alteration

    Science.gov (United States)

    Evans, O.; Spiegelman, M. W.; Kelemen, P. B.

    2017-12-01

    The interactions between reactive fluids and brittle solids are critical in Earth dynamics. Implications of such processes are wide-ranging: from earthquake physics to geologic carbon sequestration and the cycling of fluids and volatiles through subduction zones. Peridotite alteration is a common feature in many of these processes, which - despite its obvious importance - is relatively poorly understood from a geodynamical perspective. In particular, alteration reactions are thought to be self-limiting in nature, contradicting observations of rocks that have undergone 100% hydration/carbonation. One potential explanation of this observation is the mechanism of "reaction-driven cracking": that volume changes associated with these reactions are large enough to fracture the surrounding rock, leading to a positive feedback where new reactive surfaces are exposed and fluid pathways are created. The purpose of this study is to investigate the relative roles of reaction, elastic stresses and surface tension in alteration reactions. In this regard we derive a system of equations describing reactive fluid flow in an elastically deformable porous media, and explore them via a combination of analytic and numerical solutions. Using this model we show that the final stress state of a dry peridotite that has undergone reaction depends strongly on the rates of reaction versus fluid transport: significant fluid flow driven by pressure and/or surface tension gradients implies higher fractions of serpentinization, leaving behind a highly stressed residuum of partially reacted material. Using a model set-up that mimics a cylindrical triaxial apparatus we predict that the resulting stresses would lead to tensile failure and the generation of radially oriented cracks.

  1. Optimization of radially heterogeneous 1000-MW(e) LMFBR core configurations. Appendixes D and E. Research project 620-25

    International Nuclear Information System (INIS)

    Barthold, W.P.; Orechwa, Y.; Su, S.F.; Hutter, E.; Batch, R.V.; Beitel, J.C.; Turski, R.B.; Lam, P.S.K.

    1979-11-01

    A parameter study was conducted to determine the interrelated effects of: loosely or tightly coupled fuel regions separated by internal blanket assemblies, number of fuel regions, core height, number and arrangement of internal blanket subassemblies, number and size of fuel pins in a subassembly, etc. the effects of these parameters on sodium void reactivity, Doppler, incoherence, breeding gain, and thermohydraulics were of prime interest. Trends were established and ground work laid for optimization of a large, radially-heterogeneous, LMFBR core that will have low energetics in an HCDA and will have good thermal and breeding performance

  2. Expansion of a Bose-Einstein condensate formed on a joint harmonic and one-dimensional optical-lattice potential

    International Nuclear Information System (INIS)

    Adhikari, Sadhan K

    2003-01-01

    We study the expansion of a Bose-Einstein condensate trapped in a combined optical-lattice and axially-symmetric harmonic potential using the numerical solution of the mean-field Gross-Pitaevskii equation. First, we consider the expansion of such a condensate under the action of the optical-lattice potential alone. In this case the result of numerical simulation for the axial and radial sizes during expansion is in agreement with two experiments by Morsch et al (2002 Phys. Rev. A 66 021601(R) and 2003 Laser Phys. 13 594). Finally, we consider the expansion under the action of the harmonic potential alone. In this case the oscillation, and the disappearance and revival of the resultant interference pattern is in agreement with the experiment by Mueller et al (2003 J. Opt. B: Quantum Semiclass. Opt. 5 S38)

  3. Macrosegregation Due to Convection in Al-19Cu Alloy Directionally Solidified Through an Abrupt Expansion in Cross-Section: A Comparison with Al-7Si

    Science.gov (United States)

    Ghods, M.; Lauer, M.; Grugel, R. N.; Tewari, S. N.; Poirier, D. R.

    2017-10-01

    Hypoeutectic Al-19 wt.% Cu alloys were directionally solidified at two different growth speeds in cylindrical molds that featured an abrupt increase in cross-section, from 3.2 to 9.5 mm in diameter. The effects of thermosolutal convection and shrinkage flow induced by the cross-section change on macrosegregation were investigated. Dendrite clustering and extensive radial macrosegregation were seen, particularly in the larger cross-section after expansion. Negative longitudinal macrosegregation right after the cross-section increase was observed; the extent of macrosegregation, however, decreases with increasing growth speed. Both thermal and flow effects due to cross-section change were seen to influence the radial macrosegregation immediately before, and after the expansion. Radial macrosegregation pattern was found to be changing as the mushy zone enters the larger cross-section region above the cross-section change where the solidification is in its unsteady state. The effect of the solutal expansion coefficient on macrosegregation was studied by comparing the degree of thermosolutal convection in Al-19 wt.% Cu with a previous study in which we investigated Al-7 wt.% Si. A two-dimensional model accounting for both shrinkage and thermosolutal convection was used to simulate the resulting steepling, as well as the axial and radial macrosegregation. The experimentally observed macrosegregation associated with the expansion during directional solidification is well predicted by the numerical simulations.

  4. Combined Radial and Femoral Access Strategy and Radial-Femoral Rendezvous in Patients With Long and Complex Iliac Occlusions.

    Science.gov (United States)

    Hanna, Elias B; Mogabgab, Owen N; Baydoun, Hassan

    2018-01-01

    We present cases of complex, calcified iliac occlusive disease revascularized via a combined radial-femoral access strategy. Through a 6-French, 125-cm transradial guiding catheter, antegrade guidewires and catheters are advanced into the iliac occlusion, while retrograde devices are advanced transfemorally. The transradial and transfemoral channels communicate, allowing the devices to cross the occlusion into the true lumen (radial-femoral antegrade-retrograde rendezvous).

  5. Immune reactivities against gums.

    Science.gov (United States)

    Vojdani, Aristo; Vojdani, Charlene

    2015-01-01

    Different kinds of gums from various sources enjoy an extremely broad range of commercial and industrial use, from food and pharmaceuticals to printing and adhesives. Although generally recognized as safe by the US Food and Drug Administration (FDA), gums have a history of association with sensitive or allergic reactions. In addition, studies have shown that gums have a structural, molecular similarity to a number of common foods. A possibility exists for cross-reactivity. Due to the widespread use of gums in almost every aspect of modern life, the overall goal of the current investigation was to determine the degree of immune reactivity to various gum antigens in the sera of individuals representing the general population. The study was a randomized, controlled trial. 288 sera purchased from a commercial source. The sera was screened for immunoglobulin G (IgG) and immunoglobulin E (IgE) antibodies against extracts of mastic gum, carrageenan, xantham gum, guar gum, gum tragacanth, locust bean gum, and β-glucan, using indirect enzyme-linked immunosorbent assay (ELISA) testing. For each gum antigen, inhibition testing was performed on the 4 sera that showed the highest IgG and IgE immune reactivity against the different gums used in the study. Inhibition testing on these same sera for sesame albumin, lentil, corn, rice, pineapple, peanut, pea protein, shrimp, or kidney bean was used to determine the cross-reactivity of these foods with the gum. Of the 288 samples, 4.2%-27% of the specimens showed a significant elevation in IgG antibodies against various gums. Only 4 of 288, or 1.4%, showed a simultaneous elevation of the IgG antibody against all 7 gum extracts. For the IgE antibody, 15.6%-29.1% of the specimens showed an elevation against the various gums. A significant percentage of the specimens, 12.8%, simultaneously produced IgE antibodies against all 7 tested extracts. Overall, the percentage of elevation in IgE antibodies against different gum extracts, with

  6. Strain expansion-reduction approach

    Science.gov (United States)

    Baqersad, Javad; Bharadwaj, Kedar

    2018-02-01

    Validating numerical models are one of the main aspects of engineering design. However, correlating million degrees of freedom of numerical models to the few degrees of freedom of test models is challenging. Reduction/expansion approaches have been traditionally used to match these degrees of freedom. However, the conventional reduction/expansion approaches are only limited to displacement, velocity or acceleration data. While in many cases only strain data are accessible (e.g. when a structure is monitored using strain-gages), the conventional approaches are not capable of expanding strain data. To bridge this gap, the current paper outlines a reduction/expansion technique to reduce/expand strain data. In the proposed approach, strain mode shapes of a structure are extracted using the finite element method or the digital image correlation technique. The strain mode shapes are used to generate a transformation matrix that can expand the limited set of measurement data. The proposed approach can be used to correlate experimental and analytical strain data. Furthermore, the proposed technique can be used to expand real-time operating data for structural health monitoring (SHM). In order to verify the accuracy of the approach, the proposed technique was used to expand the limited set of real-time operating data in a numerical model of a cantilever beam subjected to various types of excitations. The proposed technique was also applied to expand real-time operating data measured using a few strain gages mounted to an aluminum beam. It was shown that the proposed approach can effectively expand the strain data at limited locations to accurately predict the strain at locations where no sensors were placed.

  7. Expansion of protein domain repeats.

    Directory of Open Access Journals (Sweden)

    Asa K Björklund

    2006-08-01

    Full Text Available Many proteins, especially in eukaryotes, contain tandem repeats of several domains from the same family. These repeats have a variety of binding properties and are involved in protein-protein interactions as well as binding to other ligands such as DNA and RNA. The rapid expansion of protein domain repeats is assumed to have evolved through internal tandem duplications. However, the exact mechanisms behind these tandem duplications are not well-understood. Here, we have studied the evolution, function, protein structure, gene structure, and phylogenetic distribution of domain repeats. For this purpose we have assigned Pfam-A domain families to 24 proteomes with more sensitive domain assignments in the repeat regions. These assignments confirmed previous findings that eukaryotes, and in particular vertebrates, contain a much higher fraction of proteins with repeats compared with prokaryotes. The internal sequence similarity in each protein revealed that the domain repeats are often expanded through duplications of several domains at a time, while the duplication of one domain is less common. Many of the repeats appear to have been duplicated in the middle of the repeat region. This is in strong contrast to the evolution of other proteins that mainly works through additions of single domains at either terminus. Further, we found that some domain families show distinct duplication patterns, e.g., nebulin domains have mainly been expanded with a unit of seven domains at a time, while duplications of other domain families involve varying numbers of domains. Finally, no common mechanism for the expansion of all repeats could be detected. We found that the duplication patterns show no dependence on the size of the domains. Further, repeat expansion in some families can possibly be explained by shuffling of exons. However, exon shuffling could not have created all repeats.

  8. Aneurisma idiopático de artéria radial: relato de caso Idiopathic radial artery aneurysm: case report

    Directory of Open Access Journals (Sweden)

    Luiz Ernani Meira Jr.

    2011-12-01

    Full Text Available Os aneurismas da artéria radial são extremamente raros. Em sua maioria, consistem de pseudoaneurismas pós-traumáticos. Os aneurismas da artéria radial verdadeiros podem ser idiopáticos, congênitos, pós-estenóticos ou associados a patologias, tais como vasculites e doenças do tecido conjuntivo. Foi relatado um caso de aneurisma idiopático de artéria radial em uma criança de três anos, que, após completa investigação diagnóstica complementar, foi submetida à ressecção cirúrgica.Radial artery aneurysms are extremely rare. Post-traumatic pseudoaneurysms are the vast majority. True radial artery aneurysms can be idiopathic, congenital, poststenotic, or associated with some pathologies, such as vasculitis and conjunctive tissue diseases. We report a case of an idiopathic aneurysm of the radial artery in a three-year-old child who was submitted to surgical resection after a complete diagnostic approach.

  9. Nuclear fuel reprocessing expansion strategies

    International Nuclear Information System (INIS)

    Gallagher, J.M.

    1975-01-01

    A description is given of an effort to apply the techniques of operations research and energy system modeling to the problem of determination of cost-effective strategies for capacity expansion of the domestic nuclear fuel reprocessing industry for the 1975 to 2000 time period. The research also determines cost disadvantages associated with alternative strategies that may be attractive for political, social, or ecological reasons. The sensitivity of results to changes in cost assumptions was investigated at some length. Reactor fuel types covered by the analysis include the Light Water Reactor (LWR), High-Temperature Gas-Cooled Reactor (HTGR), and the Fast Breeder Reactor (FBR)

  10. Thermal expansion of LATGS crystals

    International Nuclear Information System (INIS)

    Kassem, M.E.; Kandil, S.H.; Hamed, A.E.; Stankowska, J.

    1989-04-01

    The thermal expansion of triglycine sulphate crystals doped with L-α alanine (LATGS) has been studied around the phase transition temperature (30-60 deg. C) using thermomechanical analysis TMA. With increasing the content of admixture, the transition temperature (T c ) was shifted towards higher values, while the relative changes in the dimension of the crystals (ΔL/L 0 ) of the studied directions varied both in the para- and ferroelectric phases. The transition width in the case of doped crystals was found to be broad, and this broadening increases with increasing the content of L-α alanine. (author). 12 refs, 3 figs

  11. Contribution of thermal expansion and

    Directory of Open Access Journals (Sweden)

    O.I.Pursky

    2007-01-01

    Full Text Available A theoretical model is developed to describe the experimental results obtained for the isobaric thermal conductivity of rare gas solids (RGS. The isobaric thermal conductivity of RGS has been analysed within Debye approximation with regard to the effect of thermal expansion. The suggested model takes into consideration the fact that thermal conductivity is determined by U-processes while above the phonon mobility edge it is determined by "diffusive" modes migrating randomly from site to site. The mobility edge ω0 is determined from the condition that the phonon mean-free path restricted by the U-processes cannot be smaller than half of the phonon wavelength.

  12. Simple kinetic theory model of reactive collisions. IV. Laboratory fixed orientational cross sections

    International Nuclear Information System (INIS)

    Evans, G.T.

    1987-01-01

    The differential orientational cross section, obtainable from molecular beam experiments on aligned molecules, is calculated using the line-of-normals model for reactive collisions involving hard convex bodies. By means of kinetic theory methods, the dependence of the cross section on the angle of attack γ 0 is expressed in a Legendre function expansion. Each of the Legendre expansion coefficients is given by an integral over the molecule-fixed cross section and functions of the orientation dependent threshold energy

  13. Rehabilitation for distal radial fractures in adults.

    Science.gov (United States)

    Handoll, Helen H G; Elliott, Joanne

    2015-09-25

    Fracture of the distal radius is a common clinical problem, particularly in older people with osteoporosis. There is considerable variation in the management, including rehabilitation, of these fractures. This is an update of a Cochrane review first published in 2002 and last updated in 2006. To examine the effects of rehabilitation interventions in adults with conservatively or surgically treated distal radial fractures. We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL 2014; Issue 12), MEDLINE, EMBASE, CINAHL, AMED, PEDro, OTseeker and other databases, trial registers, conference proceedings and reference lists of articles. We did not apply any language restrictions. The date of the last search was 12 January 2015. Randomised controlled trials (RCTs) or quasi-RCTs evaluating rehabilitation as part of the management of fractures of the distal radius sustained by adults. Rehabilitation interventions such as active and passive mobilisation exercises, and training for activities of daily living, could be used on their own or in combination, and be applied in various ways by various clinicians. The review authors independently screened and selected trials, and reviewed eligible trials. We contacted study authors for additional information. We did not pool data. We included 26 trials, involving 1269 mainly female and older patients. With few exceptions, these studies did not include people with serious fracture or treatment-related complications, or older people with comorbidities and poor overall function that would have precluded trial participation or required more intensive treatment. Only four of the 23 comparisons covered by these 26 trials were evaluated by more than one trial. Participants of 15 trials were initially treated conservatively, involving plaster cast immobilisation. Initial treatment was surgery (external fixation or internal fixation) for all participants

  14. A feasibility study on wavelet transform for reactivity coefficient estimation

    International Nuclear Information System (INIS)

    Shimazu, Yoichiro

    2000-01-01

    Recently, a new method using Fourier transform has been introduced in place of the conventional method in order to reduce the time required for the measurement of moderator temperature coefficient in domestic PWRs. The basic concept of these methods is to eliminate noise in the reactivity signal. From this point of view, wavelet analysis is also known as an effective method. In this paper, we tried to apply this method to estimate reactivity coefficients of a nuclear reactor. The basic idea of the reactivity coefficient estimation is to analyze the ratios themselves of the corresponding expansion coefficients of the wavelet transform of the signals of reactivity and the relevant parameter. The concept requires no inverse wavelet transform. Based on numerical simulations, it is found that the method can reasonably estimate reactivity coefficient, for example moderator temperature coefficient, with less length of time sequence data than those required for Fourier transform method. We will continue this study to examine the validity of the estimation procedure for the actual reactor data and further to estimate the other reactivity coefficients. (author)

  15. What makes ecological systems reactive?

    Science.gov (United States)

    Snyder, Robin E

    2010-06-01

    Although perturbations from a stable equilibrium must ultimately vanish, they can grow initially, and the maximum initial growth rate is called reactivity. Reactivity thus identifies systems that may undergo transient population surges or drops in response to perturbations; however, we lack biological and mathematical intuition about what makes a system reactive. This paper presents upper and lower bounds on reactivity for an arbitrary linearized model, explores their strictness, and discusses their biological implications. I find that less stable systems (i.e. systems with long transients) have a smaller possible range of reactivities for which no perturbations grow. Systems with more species have a higher capacity to be reactive, assuming species interactions do not weaken too rapidly as the number of species increases. Finally, I find that in discrete time, reactivity is determined largely by mean interaction strength and neither discrete nor continuous time reactivity are sensitive to food web topology. 2010 Elsevier Inc. All rights reserved.

  16. Reactivity and Power Distribution Management in LEU-loaded Linear B and BR

    International Nuclear Information System (INIS)

    Hartanto, Donny; Kim, Yonghee

    2013-01-01

    In this paper, the relatively high excess reactivity issue during the initial transitional period was addressed. The design target is to achieve a maximum excess reactivity of about 1.0 dollar to prevent the possibility of the prompt jump critical accident. The initial core is divided into 2 radial Zr-zones in order to reduce the excess reactivity. By doing this, the power profile at the BOC can also be flattened. After the optimum initial core configuration has been found, the blanket region is also divided into 2 radial Zr-zones in order to flatten the power distribution at EOC. The neutronic analyses were all performed using the Monte Carlo code McCARD with ENDF-B/VII.0 library. It was found that by using the concave Zr-zoning in the initial core of B and BR, the maximum excess reactivity can be effectively lowered. The radial power profile can also be successfully flattened by using the Zr-zoning and concave initial core. The concave concept deserves more investigations for better performances of the B and BR core

  17. Bearing for the reactivation

    International Nuclear Information System (INIS)

    Santamaria Alexandra

    2003-01-01

    Ecopetrol undertook an aggressive plan to reactivate the activities of seismic that allows fulfilling the goals proposed for this year (2003). Although the production registered a descent of 9%, the financial results throw utilities for $1.1 trillion pesos to the closing of September and contributions in bonuses for $1.2 trillions. The author also refers to the general balance, to the finances, raw production, taxes and transfers

  18. Effective Geothermal Utilisation close to the surface by the TT-Geothermal Radial Drilling (GRD-Method

    Directory of Open Access Journals (Sweden)

    Hans-Joachim Bayer

    2007-01-01

    Full Text Available In the late 1970-Years, Tracto-Technik developped a very effective radial-shaped percussion system for a geothermal heating, the ECOtherm-System, which was very well accepted by customers. Nowadays, a radial-shaped drilling system, operating some decameters below the surface, was developped by Tracto-Technik, which offers the chance of a very effective drilling for the use of geothermal energy. The main advantage of this development is the reduction of drilling costs by new constructions and new handling possibilities. Drilling processes like the rod connecting or the drill-hole enlargement were solved in other ways as usual, by very time-shortening and effective ways, which are presented in the paper. The new TT-Geothermal radial drilling methods need only a very small but highly effective drilling unit, which reduces the operational drilling cost in a enormous way. All operational drilling steps are reduced to less than a half time as usual. By these GRD-methods, the use of surface-close geothermal energy is simplified and less expansive.

  19. High thermal expansion, sealing glass

    Science.gov (United States)

    Brow, R.K.; Kovacic, L.

    1993-11-16

    A glass composition is described for hermetically sealing to high thermal expansion materials such as aluminum alloys, stainless steels, copper, and copper/beryllium alloys, which includes between about 10 and about 25 mole percent Na[sub 2]O, between about 10 and about 25 mole percent K[sub 2]O, between about 5 and about 15 mole percent Al[sub 2]O[sub 3], between about 35 and about 50 mole percent P[sub 2]O[sub 5] and between about 5 and about 15 mole percent of one of PbO, BaO, and mixtures thereof. The composition, which may also include between 0 and about 5 mole percent Fe[sub 2]O[sub 3] and between 0 and about 10 mole percent B[sub 2]O[sub 3], has a thermal expansion coefficient in a range of between about 160 and 210[times]10[sup [minus]7]/C and a dissolution rate in a range of between about 2[times]10[sup [minus]7] and 2[times]10[sup [minus]9]g/cm[sup 2]-min. This composition is suitable to hermetically seal to metallic electrical components which will be subjected to humid environments over an extended period of time.

  20. Nonperturbative path integral expansion II

    International Nuclear Information System (INIS)

    Kaiser, H.J.

    1976-05-01

    The Feynman path integral representation of the 2-point function for a self-interacting Bose field is investigated using an expansion ('Path Integral Expansion', PIE) of the exponential of the kinetic term of the Lagrangian. This leads to a series - illustrated by a graph scheme - involving successively a coupling of more and more points of the lattice space commonly employed in the evaluation of path integrals. The values of the individual PIE graphs depend of course on the lattice constant. Two methods - Pade approximation and Borel-type extrapolation - are proposed to extract information about the continuum limit from a finite-order PIE. A more flexible PIE is possible by expanding besides the kinetic term a suitably chosen part of the interaction term too. In particular, if the co-expanded part is a mass term the calculation becomes only slightly more complicated than in the original formulation and the appearance of the graph scheme is unchanged. A significant reduction of the number of graphs and an improvement of the convergence of the PIE can be achieved by performing certain sums over an infinity of graph elements. (author)

  1. Inner-shell correlations and Sturm expansions in coupled perturbation calculations of atomic systems

    International Nuclear Information System (INIS)

    Sherstyuk, A.I.; Solov'eva, G.S.

    1995-01-01

    It is shown that virtual Hartree-Fock orbitals in Sturm-type expansions can be used to calculate the response of atomic systems to an external field within the framework of the coupled perturbation theory with allowance for correlation effects. The corrected electron-electron interaction in a system with field-distorted orbitals is considered by adding a nonlocal potential to a one-electron Hartree-Fock operator within each group of equivalent elections. The remaining correlation effects are calculated by solving a system of equations for corrections to the radial functions. The system is solved iteratively, with each subsequent iteration corresponding to a correction of an increasingly higher order in the electron--electron interaction. The explicit expression derived for the polarizability contains one-and two-particle radial integrals of the Sturm functions

  2. Ultra-low thermal expansion realized in giant negative thermal expansion materials through self-compensation

    OpenAIRE

    Fei-Ran Shen; Hao Kuang; Feng-Xia Hu; Hui Wu; Qing-Zhen Huang; Fei-Xiang Liang; Kai-Ming Qiao; Jia Li; Jing Wang; Yao Liu; Lei Zhang; Min He; Ying Zhang; Wen-Liang Zuo; Ji-Rong Sun

    2017-01-01

    Materials with zero thermal expansion (ZTE) or precisely tailored thermal expansion are in urgent demand of modern industries. However, the overwhelming majority of materials show positive thermal expansion. To develop ZTE or negative thermal expansion (NTE) materials as compensators has become an important challenge. Here, we present the evidence for the realization of ultra-low thermal expansion in Mn–Co–Ge–In particles. The bulk with the Ni2In-type hexagonal structure undergoes giant NTE o...

  3. Observational hints of radial migration in disc galaxies from CALIFA

    Science.gov (United States)

    Ruiz-Lara, T.; Pérez, I.; Florido, E.; Sánchez-Blázquez, P.; Méndez-Abreu, J.; Sánchez-Menguiano, L.; Sánchez, S. F.; Lyubenova, M.; Falcón-Barroso, J.; van de Ven, G.; Marino, R. A.; de Lorenzo-Cáceres, A.; Catalán-Torrecilla, C.; Costantin, L.; Bland-Hawthorn, J.; Galbany, L.; García-Benito, R.; Husemann, B.; Kehrig, C.; Márquez, I.; Mast, D.; Walcher, C. J.; Zibetti, S.; Ziegler, B.; Califa Team

    2017-07-01

    Context. According to numerical simulations, stars are not always kept at their birth galactocentric distances but they have a tendency to migrate. The importance of this radial migration in shaping galactic light distributions is still unclear. However, if radial migration is indeed important, galaxies with different surface brightness (SB) profiles must display differences in their stellar population properties. Aims: We investigate the role of radial migration in the light distribution and radial stellar content by comparing the inner colour, age, and metallicity gradients for galaxies with different SB profiles. We define these inner parts, avoiding the bulge and bar regions and up to around three disc scale lengths (type I, pure exponential) or the break radius (type II, downbending; type III, upbending). Methods: We analysed 214 spiral galaxies from the CALIFA survey covering different SB profiles. We made use of GASP2D and SDSS data to characterise the light distribution and obtain colour profiles of these spiral galaxies. The stellar age and metallicity profiles were computed using a methodology based on full-spectrum fitting techniques (pPXF, GANDALF, and STECKMAP) to the Integral Field Spectroscopic CALIFA data. Results: The distributions of the colour, stellar age, and stellar metallicity gradients in the inner parts for galaxies displaying different SB profiles are unalike as suggested by Kolmogorov-Smirnov and Anderson-Darling tests. We find a trend in which type II galaxies show the steepest profiles of all, type III show the shallowest, and type I display an intermediate behaviour. Conclusions: These results are consistent with a scenario in which radial migration is more efficient for type III galaxies than for type I systems, where type II galaxies present the lowest radial migration efficiency. In such a scenario, radial migration mixes the stellar content, thereby flattening the radial stellar properties and shaping different SB profiles. However

  4. Effect of the radial electric field on turbulence

    International Nuclear Information System (INIS)

    Carreras, B.A.; Lynch, V.E.

    1990-01-01

    For many years, the neoclassical transport theory for three- dimensional magnetic configurations, such as magnetic mirrors, ELMO Bumpy Tori (EBTs), and stellarators, has recognized the critical role of the radial electric field in the confinement. It was in these confinement devices that the first experimental measurements of the radial electric field were made and correlated with confinement losses. In tokamaks, the axisymmetry implies that the neoclassical fluxes are ambipolar and, as a consequence, independent of the radial electric field. However, axisymmetry is not strict in a tokamak with turbulent fluctuations, and near the limiter ambipolarity clearly breaks down. Therefore, the question of the effect of the radial electric field on tokamak confinement has been raised in recent years. In particular, the radial electric field has been proposed to explain the transition from L-mode to H-mode confinement. There is some initial experimental evidence supporting this type of explanation, although there is not yet a self-consistent theory explaining the generation of the electric field and its effect on the transport. Here, a brief review of recent results is presented. 27 refs., 4 figs

  5. Radial Structure Scaffolds Convolution Patterns of Developing Cerebral Cortex

    Directory of Open Access Journals (Sweden)

    Mir Jalil Razavi

    2017-08-01

    Full Text Available Commonly-preserved radial convolution is a prominent characteristic of the mammalian cerebral cortex. Endeavors from multiple disciplines have been devoted for decades to explore the causes for this enigmatic structure. However, the underlying mechanisms that lead to consistent cortical convolution patterns still remain poorly understood. In this work, inspired by prior studies, we propose and evaluate a plausible theory that radial convolution during the early development of the brain is sculptured by radial structures consisting of radial glial cells (RGCs and maturing axons. Specifically, the regionally heterogeneous development and distribution of RGCs controlled by Trnp1 regulate the convex and concave convolution patterns (gyri and sulci in the radial direction, while the interplay of RGCs' effects on convolution and axons regulates the convex (gyral convolution patterns. This theory is assessed by observations and measurements in literature from multiple disciplines such as neurobiology, genetics, biomechanics, etc., at multiple scales to date. Particularly, this theory is further validated by multimodal imaging data analysis and computational simulations in this study. We offer a versatile and descriptive study model that can provide reasonable explanations of observations, experiments, and simulations of the characteristic mammalian cortical folding.

  6. The effect of radial migration on galactic disks

    International Nuclear Information System (INIS)

    Vera-Ciro, Carlos; D'Onghia, Elena; Navarro, Julio; Abadi, Mario

    2014-01-01

    We study the radial migration of stars driven by recurring multi-arm spiral features in an exponential disk embedded in a dark matter halo. The spiral perturbations redistribute angular momentum within the disk and lead to substantial radial displacements of individual stars, in a manner that largely preserves the circularity of their orbits and that results, after 5 Gyr (∼40 full rotations at the disk scale length), in little radial heating and no appreciable changes to the vertical or radial structure of the disk. Our results clarify a number of issues related to the spatial distribution and kinematics of migrators. In particular, we find that migrators are a heavily biased subset of stars with preferentially low vertical velocity dispersions. This 'provenance bias' for migrators is not surprising in hindsight, for stars with small vertical excursions spend more time near the disk plane, and thus respond more readily to non-axisymmetric perturbations. We also find that the vertical velocity dispersion of outward migrators always decreases, whereas the opposite holds for inward migrators. To first order, newly arrived migrators simply replace stars that have migrated off to other radii, thus inheriting the vertical bias of the latter. Extreme migrators might therefore be recognized, if present, by the unexpectedly small amplitude of their vertical excursions. Our results show that migration, understood as changes in angular momentum that preserve circularity, can strongly affect the thin disk, but cast doubts on models that envision the Galactic thick disk as a relic of radial migration.

  7. A user's evaluation of radial flow HEPA filters

    International Nuclear Information System (INIS)

    Purcell, J.A.

    1992-07-01

    High efficiency particulate air (HEPA) filters of rectangular cross section have been used to remove particulates and the associated radioactivity from air ventilation streams since the advent of nuclear materials processing. Use of round axial flow HEPA filters is also longstanding. The advantages of radial flow filters in a circular configuration have been well demonstrated in UKAEA during the last 5--7 years. An evaluation of radial flow filters for fissile process gloveboxes reveals several substantial benefits in addition to the advantages claimed in UKAEA Facilities. The radial flow filter may be provided in a favorable geometry resulting in improved criticality safety. The filter configuration lends to in-place testing at the glovebox to exhaust duct interface. This will achieve compliance with DOE Order 6430.1A, Section 99.0.2. Preliminary testing at SRS for radial flow filters manufactured by Flanders Filters, Inc. revealed compliance in all the usual specifications for filtration efficiency, pressure differential and materials of construction. An evaluation, further detailed in this report, indicates that the radial flow HEPA filter should be considered for inclusion in new ventilation system designs

  8. Radial Fingering in a Porous Medium Digitation radiale dans un milieu poreux

    Directory of Open Access Journals (Sweden)

    Ni W.

    2006-11-01

    Full Text Available The theory of immiscible radial displacement in a Hele-Shaw cell is extended to the case of a porous medium contained between two closely-spaced parallel plates, and experiments are described for the displacement of glycerine by paraffin oil in such a system. Data are presented for the number of fingers, the breakthrough time, and the glycerine recovery, for a range of flowrates varying through three orders of magnitude. Good agreement between theory and experiment is observed. La théorie s'appliquant aux déplacements radiaux dans les cellules Hele-Shaw a été étendue à un système qui consiste en une couche mince de milieux poreux encapsulée entre deux plaques en verre. Dans cet article, on examine les déplacements de la glycérine par de l'huile de paraffine. En faisant varier le débit de l'huile de paraffine dans un intervalle de trois ordres de grandeur, on a étudié les variables telles que le nombre de digitations, le temps de percée et le taux de récupération de la glycérine. On a observé un bon accord entre la théorie et les résultats expérimentaux.

  9. Programming Reactive Extensions and LINQ

    CERN Document Server

    Liberty, Jesse

    2011-01-01

    Pro Reactive Extensions and LINQ is a deep dive into the next important technology for .NET developers: Reactive Extensions. This in-depth tutorial goes beyond what is available anywhere else to teach how to write WPF, Silverlight, and Windows Phone applications using the Reactive Extensions (Rx) to handle events and asynchronous method calls. Reactive programming allows you to turn those aspects of your code that are currently imperative into something much more event-driven and flexible. For this reason, it's sometimes referred to as LINQ for Events. Reactive programming hinges on the concep

  10. Radial mixing of material in the asterodial zone

    International Nuclear Information System (INIS)

    Ruzmaikina, T.V.; Safronov, V.S.; Weidenschilling, S.J.

    1989-01-01

    The asteroid belt shows radial zoning of compositional structure. The most abundant types are successively S, C and P types from the inner to the outer parts of the main belt, and D type in the Trojan clouds. Boundaries between compositional zones are not sharp, but gradual transitions over scales ∼1 AU in semimajor axis. The authors examine processes for producing this structure before, during and after the accretion of asteroids. The initial structure is established by temperature and composition gradients in the turbulent solar nebula during the collapse of the presolar cloud. The radial scale of the zoning, comparable to the disk thickness, favors disk models with relatively low turbulent viscosity. Radial decay of solid bodies due to gas drag during settling to the central plane and planetesimal formation probably causes only a small degree of mixing, due to the systematic nature of drag-induced motions

  11. Point Set Denoising Using Bootstrap-Based Radial Basis Function.

    Directory of Open Access Journals (Sweden)

    Khang Jie Liew

    Full Text Available This paper examines the application of a bootstrap test error estimation of radial basis functions, specifically thin-plate spline fitting, in surface smoothing. The presence of noisy data is a common issue of the point set model that is generated from 3D scanning devices, and hence, point set denoising is one of the main concerns in point set modelling. Bootstrap test error estimation, which is applied when searching for the smoothing parameters of radial basis functions, is revisited. The main contribution of this paper is a smoothing algorithm that relies on a bootstrap-based radial basis function. The proposed method incorporates a k-nearest neighbour search and then projects the point set to the approximated thin-plate spline surface. Therefore, the denoising process is achieved, and the features are well preserved. A comparison of the proposed method with other smoothing methods is also carried out in this study.

  12. Point Set Denoising Using Bootstrap-Based Radial Basis Function.

    Science.gov (United States)

    Liew, Khang Jie; Ramli, Ahmad; Abd Majid, Ahmad

    2016-01-01

    This paper examines the application of a bootstrap test error estimation of radial basis functions, specifically thin-plate spline fitting, in surface smoothing. The presence of noisy data is a common issue of the point set model that is generated from 3D scanning devices, and hence, point set denoising is one of the main concerns in point set modelling. Bootstrap test error estimation, which is applied when searching for the smoothing parameters of radial basis functions, is revisited. The main contribution of this paper is a smoothing algorithm that relies on a bootstrap-based radial basis function. The proposed method incorporates a k-nearest neighbour search and then projects the point set to the approximated thin-plate spline surface. Therefore, the denoising process is achieved, and the features are well preserved. A comparison of the proposed method with other smoothing methods is also carried out in this study.

  13. Rayleigh-Taylor instability of cylindrical jets with radial motion

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiang M. [GE Nuclear, Wilmington, NC (United States); Schrock, V.E.; Peterson, P.F. [Univ. of California, Berkeley, CA (United States)

    1995-09-01

    Rayleigh-Taylor instability of an interface between fluids with different densities subjected to accelleration normal to itself has interested researchers for almost a century. The classic analyses of a flat interface by Rayleigh and Taylor have shown that this type of instability depends on the direction of acceleration and the density differences of the two fluids. Plesset later analyzed the stability of a spherically symmetric flows (and a spherical interface) and concluded that the instability also depends on the velocity of the interface as well as the direction and magnitude of radial acceleration. The instability induced by radial motion in cylindrical systems seems to have been neglected by previous researchers. This paper analyzes the Rayleigh-Taylor type of the spherical case, the radial velocity also plays an important role. As an application, the example of a liquid jet surface in an Inertial Confinement Fusion (ICF) reactor design is analyzed.

  14. Mixed-Degree Spherical Simplex-Radial Cubature Kalman Filter

    Directory of Open Access Journals (Sweden)

    Shiyuan Wang

    2017-01-01

    Full Text Available Conventional low degree spherical simplex-radial cubature Kalman filters often generate low filtering accuracy or even diverge for handling highly nonlinear systems. The high-degree Kalman filters can improve filtering accuracy at the cost of increasing computational complexity; nevertheless their stability will be influenced by the negative weights existing in the high-dimensional systems. To efficiently improve filtering accuracy and stability, a novel mixed-degree spherical simplex-radial cubature Kalman filter (MSSRCKF is proposed in this paper. The accuracy analysis shows that the true posterior mean and covariance calculated by the proposed MSSRCKF can agree accurately with the third-order moment and the second-order moment, respectively. Simulation results show that, in comparison with the conventional spherical simplex-radial cubature Kalman filters that are based on the same degrees, the proposed MSSRCKF can perform superior results from the aspects of filtering accuracy and computational complexity.

  15. Reactivity costs in MARIA reactor

    International Nuclear Information System (INIS)

    Marcinkowska, Zuzanna E.; Pytel, Krzysztof M.; Frydrysiak, Andrzej

    2017-01-01

    Highlights: • The methodology for calculating consumed fuel cost of excess reactivity is proposed. • Correlation between time integral of the core excess reactivity and released energy. • Reactivity price gives number of fuel elements required for given excess reactivity. - Abstract: For the reactor operation at high power level and carrying out experiments and irradiations the major cost of reactor operation is the expense of nuclear fuel. In this paper the methodology for calculating consumed fuel cost-relatedness of excess reactivity is proposed. Reactivity costs have been determined on the basis of operating data. A number of examples of calculating the reactivity costs for processes such as: strong absorbing material irradiation, molybdenium-99 production, beryllium matrix poisoning and increased moderator temperature illustrates proposed method.

  16. Expansion of passive safety function

    International Nuclear Information System (INIS)

    Inai, Nobuhiko; Nei, Hiromichi; Kumada, Toshiaki.

    1995-01-01

    Expansion of the use of passive safety functions is proposed. Two notions are presented. One is that, in the design of passive safety nuclear reactors where aversion of active components is stressed, some active components are purposely introduced, by which a system is built in such a way that it behaves in an apparently passive manner. The second notion is that, instead of using a passive safety function alone, a passive safety function is combined with some active components, relating the passivity in the safety function with enhanced controllability in normal operation. The nondormant system which the authors propose is one example of the first notion. This is a system in which a standby safety system is a portion of the normal operation system. An interpretation of the nondormant system via synergetics is made. As an example of the second notion, a PIUS density lock aided with active components is proposed and is discussed

  17. Sharp Dissection versus Electrocautery for Radial Artery Harvesting

    Science.gov (United States)

    Marzban, Mehrab; Arya, Reza; Mandegar, Mohammad Hossein; Karimi, Abbas Ali; Abbasi, Kiomars; Movahed, Namvar; Abbasi, Seyed Hesameddin

    2006-01-01

    Radial arteries have been increasingly used during the last decade as conduits for coronary artery revascularization. Although various harvesting techniques have been described, there has been little comparative study of arterial damage and patency. A radial artery graft was used in 44 consecutive patients, who were randomly divided into 2 groups. In the 1st group, the radial artery was harvested by sharp dissection and in the 2nd, by electrocautery. These groups were compared with regard to radial artery free flow, harvest time, number of clips used, complications, and endothelial damage. Radial artery free flow before and after intraluminal administration of papaverine was significantly greater in the electrocautery group (84.3 ± 50.7 mL/min and 109.7 ± 68.5 mL/min) than in the sharp-dissection group (52.9 ± 18.3 mL/min and 69.6 ± 28.2 mL/ min) (P =0.003). Harvesting time by electrocautery was significantly shorter (25.4 ± 4.3 min vs 34.4 ± 5.9 min) (P =0.0001). Electrocautery consumed an average of 9.76 clips, versus 22.45 clips consumed by sharp dissection. The 2 groups were not different regarding postoperative complications, except for 3 cases of temporary paresthesia of the thumb in the electrocautery group; histopathologic examination found no endothelial damage. We conclude that radial artery harvesting by electrocautery is faster and more economical than harvesting by sharp dissection and is associated with better intraoperative flow and good preservation of endothelial integrity. PMID:16572861

  18. Multi objective Flower Pollination Algorithm for solving capacitor placement in radial distribution system using data structure load flow analysis

    Directory of Open Access Journals (Sweden)

    Tamilselvan V.

    2016-06-01

    Full Text Available The radial distribution system is a rugged system, it is also the most commonly used system, which suffers by loss and low voltage at the end bus. This loss can be reduced by the use of a capacitor in the system, which injects reactive current and also improves the voltage magnitude in the buses. The real power loss in the distribution line is the I2R loss which depends on the current and resistance. The connection of the capacitor in the bus reduces the reactive current and losses. The loss reduction is equal to the increase in generation, necessary for the electric power provided by firms. For consumers, the quality of power supply depends on the voltage magnitude level, which is also considered and hence the objective of the problem becomes the multi objective of loss minimization and the minimization of voltage deviation. In this paper, the optimal location and size of the capacitor is found using a new computational intelligent algorithm called Flower Pollination Algorithm (FPA. To calculate the power flow and losses in the system, novel data structure load flow is introduced. In this, each bus is considered as a node with bus associated data. Links between the nodes are distribution lines and their own resistance and reactance. To validate the developed FPA solutions standard test cases, IEEE 33 and IEEE 69 radial distribution systems are considered.

  19. Interactions between Radial Electric Field, Transport and Structure in Helical Plasmas

    International Nuclear Information System (INIS)

    Ida, Katsumi and others

    2006-01-01

    Control of the radial electric field is considered to be important in helical plasmas, because the radial electric field and its shear are expected to reduce neoclassical and anomalous transport, respectively. Particle and heat transport, that determines the radial structure of density and electron profiles, sensitive to the structure of radial electric field. On the other hand, the radial electric field itself is determined by the plasma parameters. In general, the sign of the radial electric field is determined by the plasma collisionality, while the magnitude of the radial electric field is determined by the temperature and/or density gradients. Therefore the structure of radial electric field and temperature and density are strongly coupled through the particle and heat transport and formation mechanism of radial electric field. Interactions between radial electric field, transport and structure in helical plasmas is discussed based on the experiments on Large Helical Device

  20. On the Equisummability of Hermite and Fourier Expansions

    Indian Academy of Sciences (India)

    We prove an equisummability result for the Fourier expansions and Hermite expansions as well as special Hermite expansions. We also prove the uniform boundedness of the Bochner-Riesz means associated to the Hermite expansions for polyradial functions.

  1. Reactivity insertion accident analysis

    International Nuclear Information System (INIS)

    Moreira, J.M.L.; Nakata, H.; Yorihaz, H.

    1990-04-01

    The correct prediction of postulated accidents is the fundamental requirement for the reactor licensing procedures. Accident sequences and severity of their consequences depend upon the analysis which rely on analytical tools which must be validated against known experimental results. Present work presents a systematic approach to analyse and estimate the reactivity insertion accident sequences. The methodology is based on the CINETHICA code which solves the point-kinetics/thermohydraulic coupled equations with weighted temperature feedback. Comparison against SPERT experimental results shows good agreement for the step insertion accidents. (author) [pt

  2. Bilateral radial neck fractures – A Case Report

    Directory of Open Access Journals (Sweden)

    ABY Ng

    2007-11-01

    Full Text Available Radial head and neck fractures are the most frequently seen elbow fractures. The usual cause of this injury is a fall onto an outstretched hand with a partly flexed elbow. We report here an unusual case of bilateral non-displaced radial neck fractures in a patient who presented with complaints of pain in both elbows following a simple fall. This case highlights the need for a high index of suspicion in the diagnosis of multiple injuries, no matter how `trivial` the mechanism of injury.

  3. Monte Carlo based radial shield design of typical PWR reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gul, Anas; Khan, Rustam; Qureshi, M. Ayub; Azeem, Muhammad Waqar; Raza, S.A. [Pakistan Institute of Engineering and Applied Sciences, Islamabad (Pakistan). Dept. of Nuclear Engineering; Stummer, Thomas [Technische Univ. Wien (Austria). Atominst.

    2016-11-15

    Neutron and gamma flux and dose equivalent rate distribution are analysed in radial and shields of a typical PWR type reactor based on the Monte Carlo radiation transport computer code MCNP5. The ENDF/B-VI continuous energy cross-section library has been employed for the criticality and shielding analysis. The computed results are in good agreement with the reference results (maximum difference is less than 56 %). It implies that MCNP5 a good tool for accurate prediction of neutron and gamma flux and dose rates in radial shield around the core of PWR type reactors.

  4. Imaging of radial wrist pain. I. Imaging modalities and anatomy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ryan Ka Lok; Griffith, James F.; Ng, Alex Wing Hung [The Chinese University of Hong Kong, Department of Imaging and Interventional Radiology, Prince of Wales Hospital, Hong Kong, Shatin (China); Wong, Clara Wing Yee [The Chinese University of Hong Kong, Department of Orthopedics and Traumatology, Shatin (China)

    2014-06-15

    Radial wrist pain is a common clinical complaint. The relatively complex anatomy in this region, combined with the small size of the anatomical structures and occasionally subtle imaging findings, can pose problems when trying to localize the exact cause of pain. To fully comprehend the underlying pathology, one needs a good understanding of both radial-sided wrist anatomy and the relative merits of the different imaging techniques used to assess these structures. In part I of this review, these aspects will be discussed. (orig.)

  5. Bessel-like beams modulated by arbitrary radial functions

    Science.gov (United States)

    Herman; Wiggins

    2000-06-01

    An approximate method for determining the radial and axial intensity of a Bessel-like beam is presented for the general case in which a radial Bessel distribution of any order is modulated by an arbitrary function. For Bessel-Gauss, generalized Bessel-Gauss, and Bessel-super-Gauss beams, this simple approximation yields results that are very close to the exact values, while they are exact for Bessel beams. A practical beam that can be generated with a combination of simple lenses is also analyzed and illustrated.

  6. Radial multipliers on amalgamated free products of II-factors

    DEFF Research Database (Denmark)

    Möller, Sören

    2014-01-01

    Let ℳi be a family of II1-factors, containing a common II1-subfactor 풩, such that [ℳi : 풩] ∈ ℕ0 for all i. Furthermore, let ϕ: ℕ0 → ℂ. We show that if a Hankel matrix related to ϕ is trace-class, then there exists a unique completely bounded map Mϕ on the amalgamated free product of the ℳi...... with amalgamation over 풩, which acts as a radial multiplier. Hereby, we extend a result of Haagerup and the author for radial multipliers on reduced free products of unital C*- and von Neumann algebras....

  7. Communication between radial nerve and medial cutaneous nerve of forearm

    Directory of Open Access Journals (Sweden)

    R R Marathe

    2010-01-01

    Full Text Available Radial nerve is usually a branch of the posterior cord of the brachial plexus. It innervates triceps, anconeous, brachialis, brachioradialis, extensor carpi radialis longus muscles and gives the posterior cutaneous nerve of the arm, lower lateral cutaneous nerve of arm, posterior cutaneous nerve of forearm; without exhibiting any communication with the medial cutaneous nerve of forearm or any other nerve. We report communication between the radial nerve and medial cutaneous nerve of forearm on the left side in a 58-year-old male cadaver. The right sided structures were found to be normal. Neurosurgeons should keep such variations in mind while performing the surgeries of axilla and upper arm.

  8. Tight focusing of radially polarized circular Airy vortex beams

    Science.gov (United States)

    Chen, Musheng; Huang, Sujuan; Shao, Wei

    2017-11-01

    Tight focusing properties of radially polarized circular Airy vortex beams (CAVB) are studied numerically. The light field expressions for the focused fields are derived based on vectorial Debye theory. We also study the relationship between focal profiles, such as light intensity distribution, radius of focal spot and focal length, and the parameters of CAVB. Numerical results demonstrate that we can generate a radially polarized CAVB with super-long focal length, super-strong longitudinal intensity or subwavelength focused spot at the focal plane by properly choosing the parameters of incident light and high numerical aperture (NA) lens. These results have potential applications for optical trapping, optical storage and particle acceleration.

  9. Studies of radial distortions of the ATLAS Inner Detector

    CERN Document Server

    The ATLAS collaboration

    2018-01-01

    The measurement of the absolute momentum scale of charged particles provided by the ATLAS inner detector is affected by biases related to geometrical deformations which are not well constrained by the track-based alignment procedure. The focus of this note is on momentum biases related to radial distortions of the inner detector. The $J/\\psi$, $\\Upsilon$, and $Z$-boson resonances decaying into pairs of muons are used to study and quantify such radial distortions in the barrel region of the inner detector. The analysis is performed on data collected in 2016 during Run 2 of the Large Hadron Collider, and corresponding to 33 fb$^{-1}$ of integrated luminosity.

  10. Bifurcated transition of radial transport in the HIEI tandem mirror

    International Nuclear Information System (INIS)

    Sakai, O.; Yasaka, Y.

    1995-01-01

    Transition to a high radial confinement mode in a mirror plasma is triggered by limiter biasing. Sheared plasma rotation is induced in the high confinement phase which is characterized by reduction of edge turbulence and a confinement enhancement factor of 2-4. Edge plasma parameters related to radial confinement show a hysteresis phenomenon as a function of bias voltage or bias current, leading to the fact that transition from low to high confinement mode occurs between the bifurcated states. A transition model based on azimuthal momentum balance is employed to clarify physics of the observed bifurcation. copyright 1995 American Institute of Physics

  11. Modeling the Radial Color Profile of M31

    Directory of Open Access Journals (Sweden)

    Semionov D.

    2003-12-01

    Full Text Available We present a preliminary study of a fragment of the radial color profile of the spiral galaxy M 31 in terms of 2-D model accounting for internal extinction in the disk. The two stellar population disk model was assumed. The old dust-free disk population is represented by the double exponential law, and the young disk population, well mixed with the dust, resides in spiral arms of various scale-heights. We find a good agreement among the radial color B-R profiles produced by this simple model and the profile measured around the spiral arm S4 of M 31.

  12. Radially polarized conical beam from an embedded etched fiber.

    Science.gov (United States)

    Kalaidji, Djamel; Spajer, Michel; Marthouret, Nadège; Grosjean, Thierry

    2009-06-15

    We propose a method for producing a conical beam based on the lateral refraction of the TM(01) mode from a two-mode fiber after chemical etching of the cladding, and for controlling its radial polarization. The whole power of the guided mode is transferred to the refracted beam with low diffraction. Polarization control by a series of azimuthal detectors and a stress controller affords the transmission of a stabilized radial polarization through an optical fiber. A solid component usable for many applications has been obtained.

  13. Transport profiles induced by radially localized modes in tokamak

    International Nuclear Information System (INIS)

    Beklemishev, A.D.; Horton, W.

    1991-04-01

    We describe a new approach to the calculation of turbulent transport coefficients for radially localized modes. The theory takes into account the nonuniformity of the distribution of rational (resonant) magnetic surfaces in minor radius. This distribution function is proportional to the density of available states of excitation. The resulting density of state correction qualitatively changes the radial profile of the transport coefficients, as compared to the usual local diffusivity formulae. The correction factor calculated for the η i -mode transport allows a much better agreement of χ i with the experimental data than previously achieved. 8 refs., 3 figs

  14. THE RADIAL VELOCITY EXPERIMENT (RAVE): THIRD DATA RELEASE

    International Nuclear Information System (INIS)

    Siebert, A.; Williams, M. E. K.; Siviero, A.; Boeche, C.; Steinmetz, M.; De Jong, R. S.; Enke, H.; Anguiano, B.; Reid, W.; Ritter, A.; Fulbright, J.; Wyse, R. F. G.; Munari, U.; Zwitter, T.; Watson, F. G.; Burton, D.; Cass, C. J. P.; Fiegert, K.; Hartley, M.; Russel, K. S.

    2011-01-01

    We present the third data release of the RAdial Velocity Experiment (RAVE) which is the first milestone of the RAVE project, releasing the full pilot survey. The catalog contains 83,072 radial velocity measurements for 77,461 stars in the southern celestial hemisphere, as well as stellar parameters for 39,833 stars. This paper describes the content of the new release, the new processing pipeline, as well as an updated calibration for the metallicity based upon the observation of additional standard stars. Spectra will be made available in a future release. The data release can be accessed via the RAVE Web site.

  15. Computer simulation of radial transport in tandem mirror machines

    International Nuclear Information System (INIS)

    Gilmore, J.M.

    1979-01-01

    A code used for simulation of classical radial transport in the 2XIIB experiment has been modified to simulate radial transport in TMX. Results have been obtained using classical transport coefficients and also using very simple trial neoclassical resonant transport coefficients. Comparison of the results obtained with solely classical transport and with both classical and neo-classical transport indicate that neoclassical transport depresses the ion density by approximately 5%. The central cell ion temperature is increased by approximately by the neo-classical transport, as is the electron temperature

  16. Matching problems in pulse power radial transmission lines

    International Nuclear Information System (INIS)

    Mittag, K.; Brandelik, A.

    1984-12-01

    In this report we study the power transfer from a generator along a coaxial transmission line followed by a radial transmission line into a load, which in our application is a pseudo-spark plasma of about one millimeter diameter and about 15 cm in length. First the theoretical background based on transmission line theory is described. Then numerical results are presented. The main conclusion is that when matching the pulse power generator to the pseudo-spark plasma, the effect of the impedance transformation caused by the radial transmission line has to be taken into account. The conditions to obtain an optimal match are described. (orig.) [de

  17. The CERES/NA45 radial drift Time Projection Chamber

    Science.gov (United States)

    Adamová, D.; Agakichiev, G.; Antończyk, D.; Appelshäuser, H.; Belaga, V.; Bielčíková, J.; Braun-Munzinger, P.; Campagnolo, R.; Cherlin, A.; Damjanović, S.; Dietel, T.; Dietrich, L.; Drees, A.; Dubitzky, W.; Esumi, S. I.; Filimonov, K.; Fraenkel, Z.; Garabatos, C.; Glässel, P.; Hering, G.; Holeczek, J.; Kushpil, V.; Marín, A.; Milošević, J.; Milov, A.; Miśkowiec, D.; Musa, L.; Panebrattsev, Y.; Pechenova, O.; Petráček, V.; Pfeiffer, A.; Rak, J.; Ravinovich, I.; Richter, M.; Sako, H.; Schäfer, E.; Schmitz, W.; Schukraft, J.; Seipp, W.; Sharma, A.; Shimansky, S.; Stachel, J.; Šumbera, M.; Tilsner, H.; Tserruya, I.; Wessels, J. P.; Wienold, T.; Windelband, B.; Wurm, J. P.; Xie, W.; Yurevich, S.; Yurevich, V.

    2008-08-01

    The design, calibration, and performance of the first radial drift Time Projection Chamber (TPC) are presented. The TPC was built and installed at the CERES/NA45 experiment at the CERN SPS in the late nineties, with the objective to improve the momentum resolution of the spectrometer. The upgraded experiment took data twice, in 1999 and in 2000. After a detailed study of residual distortions a spatial resolution of 340 μm in the azimuthal and 640 μm in the radial direction was achieved, corresponding to a momentum resolution of Δp/p=√{(1%·p/GeV)2+(2%)2}.

  18. The CERES/NA45 radial drift Time Projection Chamber

    CERN Document Server

    AUTHOR|(CDS)2073202; Antonczyk, D; Appelshäuser, H; Belaga, V; Bielcikova, J; Braun-Munzinger, P; Campagnolo, R; Cherlin, A; Damjanovic, S; Dietel, T; Dietrich, L; Drees, A; Dubitzky, W; Esumi, S I; Filimonov, K; Fraenkel, Zeev; Garabatos, C; Glässel, P; Hering, G; Holeczek, J; Kushpil, V; Marin, A; Milosevic, J; Milov, A; Mikowiec, D; Musa, L; Panebratsev, Yu A; Pechenova, O; Petretracek, V; Pfeiffer, A; Rak, J; Ravinovich, I; Richter, M; Sako, H; Schäfer, E; Schmitz, W; Schükraft, J; Seipp, W; Sharma, A; Shimansky, S; Stachel, J; Sumbera, M; Tilsner, H; Tserruya, Itzhak; Wessels, J P; Wienoldh, T; Windelband, B; Wurm, J P; Xie, W; Yurevich, S; Yurevich, V

    2008-01-01

    The design, calibration, and performance of the first radial drift Time Projection Chamber (TPC) are presented. The TPC was built and installed at the CERES/NA45 experiment at the CERN SPS in the late nineties, with the objective to improve the momentum resolution of the spectrometer. The upgraded experiment took data twice, in 1999 and in 2000. After a detailed study of residual distortions a spatial resolution of 340 um in the azimuthal and 640 um in the radial direction was achieved, corresponding to a momentum resolution of Dp/p = sqrt{(1% * p/GeV)^2 + (2%)^2}.

  19. MRI of radial displacement of the meniscus in the knee

    International Nuclear Information System (INIS)

    Chen Jian; Lv Houshan; Lao Shan; Guan Zhenpeng; Hong Nan; Liang Hao

    2006-01-01

    Objective: To describe the phenomenon of radial displacement of the meniscus of the knees in the study population with MR imaging, and to establish MRI diagnostic criteria for radial displacement of the meniscus and displacement index. Methods: MR signs of radial displacement of the meniscus were evaluated retrospectively in 398 patients with knee symptoms who were examined with non- weight bearing MR images from Jan. 2000 to Feb. 2004. The patients younger than 18 years old, with joint effusion or serious arthropathy were excluded and 312 patients were eligible to be enrolled in this study. The criterion for radial displacement of the meniscus was defined as the location of the edge of meniscal body beyond the femoral and tibial outer border line. A displacement index, defined as the ratio of meniscal overhang to meniscal width, was used to quantify meniscal displacement. Results: The prevalence of radial displacement of the meniscus was 16.7% (52/312) and 13.9% (21/151) in right knee and 19.3% (31/161 )in left knee, respectively. There was no significant difference between left and right knee (χ 2 =1.60, P>0.05) and the ratio between medial and lateral meniscus was 7.8:1. The average displacement index was 0.54±0.24. The displacement indices were significant higher in older group (F=3.63, P<0.05). The incidence and indices of radial displacement of the meniscus for patients under or above 50 year older were 12.0%(17/142), 0.46±0.22 and 20.6% (35/170), 0.64±0.20, respectively. Difference was highly significant (t=0.84, P<0.01). Conclusion: It was concluded that radial displacement of the meniscus in knees was not a rare finding with MR imaging in patients with knee symptoms. The incidence increased in older age group. Further investigations were recommended to understand the etiology and clinical significance of the phenomenon of radial displacement of the meniscus. (authors)

  20. [Tissular expansion in giant congenital nevi treatment].

    Science.gov (United States)

    Nguyen Van Nuoi, V; Francois-Fiquet, C; Diner, P; Sergent, B; Zazurca, F; Franchi, G; Buis, J; Vazquez, M-P; Picard, A; Kadlub, N

    2014-08-01

    Surgical management of giant melanotic naevi remains a surgical challenge. Tissue expansion provides tissue of the same quality for the repair of defects. The aim of this study is to review tissular expansion for giant melanotic naevi. We conducted a retrospective study from 2000 to 2012. All children patients who underwent a tissular expansion for giant congenital naevi had been included. Epidemiological data, surgical procedure, complication rate and results had been analysed. Thirty-tree patients had been included; they underwent 61 procedures with 79 tissular-expansion prosthesis. Previous surgery, mostly simple excision had been performed before tissular expansion. Complete naevus excision had been performed in 63.3% of the cases. Complications occurred in 45% of the cases, however in 50% of them were minor. Iterative surgery increased the complication rate. Tissular expansion is a valuable option for giant congenital naevus. However, complication rate remained high, especially when iterative surgery is needed. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  1. Simulation program for multiple expansion Stirling machines

    International Nuclear Information System (INIS)

    Walker, G.; Weiss, M.; Fauvel, R.; Reader, G.; Bingham, E.R.

    1992-01-01

    Multiple expansion Stirling machines have been a topic of interest at the University of Calgary for some years. Recently a second-order computer simulation program with integral graphics package for Stirling cryocoolers with up to four stages of expansion were developed and made available to the Stirling community. Adaptation of the program to multiple expansion Stirling power systems is anticipated. This paper briefly introduces the program and presents a specimen result

  2. Semiclassical expansions for confined N fermion systems

    International Nuclear Information System (INIS)

    Krivine, H.; Martorell, J.; Casas, M.

    1989-01-01

    A new derivation of the Wigner Kirkwood expansion for N-fermion systems is presented, showing explicitly the connection to the WKB approximation for a single level. This allows to study separately the two ansatz required to obtain the semiclassical expansions: the asymptotic expansions in powers of ℎ and the smoothing of quantal effects. We discuss the one dimensional and three dimensional, with spherical symmetry, cases. Applications for standard potentials used in nuclear physics are described in detail

  3. Thermal and hygroscopic expansion characteristics of bamboo

    OpenAIRE

    Huang, Puxi; Chang, Wen-shao; Ansell, Martin P.; Bowen, Chris R.; Chew, John Y. M.; Adamak, Vana i

    2017-01-01

    The expansion and contraction of bamboo caused by temperature and moisture variations must be evaluated\\ud if bamboo is to be utilised as a building material. However, detailed expansion data, especially data in the ascent and\\ud descent processes of temperature and moisture are unexplored. The aim of this study is to investigate the expansion\\ud characteristics of Phyllostachys edulis (Moso bamboo) in ascent and descent processes of temperature and moisture.\\ud The measurement of linear ther...

  4. $\\delta$-Expansion at Finite Temperature

    OpenAIRE

    Ramos, Rudnei O.

    1996-01-01

    We apply the $\\delta$-expansion perturbation scheme to the $\\lambda \\phi^{4}$ self-interacting scalar field theory in 3+1 D at finite temperature. In the $\\delta$-expansion the interaction term is written as $\\lambda (\\phi^{2})^{ 1 + \\delta}$ and $\\delta$ is considered as the perturbation parameter. We compute within this perturbative approach the renormalized mass at finite temperature at a finite order in $\\delta$. The results are compared with the usual loop-expansion at finite temperature.

  5. Chromatic Derivatives, Chromatic Expansions and Associated Spaces

    OpenAIRE

    Ignjatovic, Aleksandar

    2009-01-01

    This paper presents the basic properties of chromatic derivatives and chromatic expansions and provides an appropriate motivation for introducing these notions. Chromatic derivatives are special, numerically robust linear differential operators which correspond to certain families of orthogonal polynomials. Chromatic expansions are series of the corresponding special functions, which possess the best features of both the Taylor and the Shannon expansions. This makes chromatic derivatives and ...

  6. Thermal expansion in small metallic particles

    International Nuclear Information System (INIS)

    Ivanov, A.S.

    1985-01-01

    An anomalously low thermal expansion observable in small particles is attributed to extending effect of the shell. It is shown that the coefficient of thermal expansion of the oxide-film-coated aluminium particles calculated using elastic constants and coefficients of thermal expansion of massive materials agres well with those measured experimentally. The linear dilatation of the shell, its stress to rupture and the values of the structural tension are estimated vs the temperature

  7. Detonative propagation and accelerative expansion of the Crab Nebula shock front.

    Science.gov (United States)

    Gao, Yang; Law, Chung K

    2011-10-21

    The accelerative expansion of the Crab Nebula's outer envelope is a mystery in dynamics, as a conventional expanding blast wave decelerates when bumping into the surrounding interstellar medium. Here we show that the strong relativistic pulsar wind bumping into its surrounding nebula induces energy-generating processes and initiates a detonation wave that propagates outward to form the current outer edge, namely, the shock front, of the nebula. The resulting detonation wave, with a reactive downstream, then provides the needed power to maintain propagation of the shock front. Furthermore, relaxation of the curvature-induced reduction of the propagation velocity from the initial state of formation to the asymptotic, planar state of Chapman-Jouguet propagation explains the observed accelerative expansion. Potential richness in incorporating reactive fronts in the description of various astronomical phenomena is expected. © 2011 American Physical Society

  8. Reactive documentation system

    Science.gov (United States)

    Boehnlein, Thomas R.; Kramb, Victoria

    2018-04-01

    Proper formal documentation of computer acquired NDE experimental data generated during research is critical to the longevity and usefulness of the data. Without documentation describing how and why the data was acquired, NDE research teams lose capability such as their ability to generate new information from previously collected data or provide adequate information so that their work can be replicated by others seeking to validate their research. Despite the critical nature of this issue, NDE data is still being generated in research labs without appropriate documentation. By generating documentation in series with data, equal priority is given to both activities during the research process. One way to achieve this is to use a reactive documentation system (RDS). RDS prompts an operator to document the data as it is generated rather than relying on the operator to decide when and what to document. This paper discusses how such a system can be implemented in a dynamic environment made up of in-house and third party NDE data acquisition systems without creating additional burden on the operator. The reactive documentation approach presented here is agnostic enough that the principles can be applied to any operator controlled, computer based, data acquisition system.

  9. Disjoint sum expansion method in FTA

    International Nuclear Information System (INIS)

    Ruan Keqiang

    1987-01-01

    An expansion formula for transforming boolean algebraic expressions into disjoint form was proved. Based on this expansion formula, a method for transforming system failure function into disjoint form was devised. The fact that the expansion can be done for several elements simulatneously makes the method flexible and fast. Some examples from fault tree analysis (FTA) and network analysis were examined by the new method to show its algorithm and its merit. Besides, by means of the proved expansion formula some boolean algebraic relations can proved very easily

  10. Thermal expansion of L-ascorbic acid

    Science.gov (United States)

    Nicolaï, B.; Barrio, M.; Tamarit, J.-Ll.; Céolin, R.; Rietveld, I. B.

    2017-04-01

    The specific volume of vitamin C has been investigated by X-ray powder diffraction as a function of temperature from 110 K up to complete degradation around 440 K. Its thermal expansion is relatively small in comparison with other organic compounds with an expansivity α v of 1.2(3) × 10-4 K-1. The structure consists of strongly bound molecules in the ac plane through a dense network of hydrogen bonds. The thermal expansion is anisotropic. Along the b axis, the expansion has most leeway and is about 10 times larger than in the other directions.

  11. Adiabatic supernova expansion into the circumstellar medium

    International Nuclear Information System (INIS)

    Band, D.L.; Liang, E.P.

    1987-01-01

    We perform one dimensional numerical simulations with a Lagrangian hydrodynamics code of the adiabatic expansion of a supernova into the surrounding medium. The early expansion follows Chevalier's analytic self-similar solution until the reverse shock reaches the ejecta core. We follow the expansion as it evolves towards the adiabatic blast wave phase. Some memory of the earlier phases of expansion is retained in the interior even when the outer regions expand as a blast wave. We find the results are sensitive to the initial configuration of the ejecta and to the placement of gridpoints. 6 refs., 2 figs

  12. Sensitivity analysis for reactivity parameter change of the creole experiment caused by the differences between ENDF-BVII and JENDL neutron cross section evaluations

    International Nuclear Information System (INIS)

    Boulaich, Y.; Bardouni, C.; Elyounoussi, C.; Elbakkari, H.; Boukhal, H.; Erradi, L.; Nacir, B.

    2011-01-01

    Full text: In this work, we present our analysis of the CREOLE experiment on the parameter by using the three-dimensional continuous energy code (MCNPS) and the last updated nuclear data evaluations. This experiment performed in the EOLE critical facility located at CEA-Cadarache, was dedicated to studies for both UO2 and UO2-PuO2 PWR type lattices covering the whole temperature range from 20 0 C to 300 0 C. We have developed an accurate model of the EOLE reactor to be used by the MCNP5 Monte Carlo code. This model guarantees a high level of fidelity in the description of different configurations at various temperatures taking into account their consequence on neutron cross section data and all thermal expansion effects. In this case, the remaining error between calculation and experiment will be awarded mainly to uncertainties on nuclear data. Our own cross section library was constructed by using NJOY99.259 code with point-wise nuclear data based on ENDF-BVII. JEFF3.1, JENDL3.3 and JENDL4 evaluation files. The MCNP model was validated through the axial and radial fission rate measurements at room and hot temperatures. Calculation-experiment discrepancies of the reactivity parameter were analyzed and the results have shown that the JENDL evaluations give the most consistent values. In order to specify the source of the relatively large difference between experiment and calculation due to ENDF-BVII nuclear data evaluation, the discrepancy in reactivity between ENDF-BVII and JENDL evaluations was decomposed using sensitivity and uncertainty analysis technique

  13. A Novel Integrated Structure with a Radial Displacement Sensor and a Permanent Magnet Biased Radial Magnetic Bearing

    Directory of Open Access Journals (Sweden)

    Jinji Sun

    2014-01-01

    Full Text Available In this paper, a novel integrated structure is proposed in order to reduce the axial length of the high speed of a magnetically suspended motor (HSMSM to ensure the maximum speed, which combines radial displacement sensor probes and the permanent magnet biased radial magnetic bearing in HSMSM. The sensor probes are integrated in the magnetic bearing, and the sensor preamplifiers are placed in the control system of the HSMSM, separate from the sensor probes. The proposed integrated structure can save space in HSMSMs, improve the working frequency, reduce the influence of temperature on the sensor circuit, and improve the stability of HSMSMs.

  14. Microtubules Nonlinear Models Dynamics Investigations through the exp(−Φ(ξ-Expansion Method Implementation

    Directory of Open Access Journals (Sweden)

    Nur Alam

    2016-02-01

    Full Text Available In this research article, we present exact solutions with parameters for two nonlinear model partial differential equations(PDEs describing microtubules, by implementing the exp(−Φ(ξ-Expansion Method. The considered models, describing highly nonlinear dynamics of microtubules, can be reduced to nonlinear ordinary differential equations. While the first PDE describes the longitudinal model of nonlinear dynamics of microtubules, the second one describes the nonlinear model of dynamics of radial dislocations in microtubules. The acquired solutions are then graphically presented, and their distinct properties are enumerated in respect to the corresponding dynamic behavior of the microtubules they model. Various patterns, including but not limited to regular, singular kink-like, as well as periodicity exhibiting ones, are detected. Being the method of choice herein, the exp(−Φ(ξ-Expansion Method not disappointing in the least, is found and declared highly efficient.

  15. Expansion of direction space around the cardinal axes revealed by smooth pursuit eye movements

    Science.gov (United States)

    Krukowski, Anton E.; Stone, Leland S.

    2005-01-01

    It is well established that perceptual direction discrimination shows an oblique effect; thresholds are higher for motion along diagonal directions than for motion along cardinal directions. Here, we compare simultaneous direction judgments and pursuit responses for the same motion stimuli and find that both pursuit and perceptual thresholds show similar anisotropies. The pursuit oblique effect is robust under a wide range of experimental manipulations, being largely resistant to changes in trajectory (radial versus tangential motion), speed (10 versus 25 deg/s), directional uncertainty (blocked versus randomly interleaved), and cognitive state (tracking alone versus concurrent tracking and perceptual tasks). Our data show that the pursuit oblique effect is caused by an effective expansion of direction space surrounding the cardinal directions and the requisite compression of space for other directions. This expansion suggests that the directions around the cardinal directions are in some way overrepresented in the visual cortical pathways that drive both smooth pursuit and perception.

  16. Aft-body loading function for penetrators based on the spherical cavity-expansion approximation.

    Energy Technology Data Exchange (ETDEWEB)

    Longcope, Donald B., Jr.; Warren, Thomas Lynn; Duong, Henry

    2009-12-01

    In this paper we develop an aft-body loading function for penetration simulations that is based on the spherical cavity-expansion approximation. This loading function assumes that there is a preexisting cavity of radius a{sub o} before the expansion occurs. This causes the radial stress on the cavity surface to be less than what is obtained if the cavity is opened from a zero initial radius. This in turn causes less resistance on the aft body as it penetrates the target which allows for greater rotation of the penetrator. Results from simulations are compared with experimental results for oblique penetration into a concrete target with an unconfined compressive strength of 23 MPa.

  17. Analysis of the stress field in a wedge using the fast expansions with pointwise determined coefficients

    Science.gov (United States)

    Chernyshov, A. D.; Goryainov, V. V.; Danshin, A. A.

    2018-03-01

    The stress problem for the elastic wedge-shaped cutter of finite dimensions with mixed boundary conditions is considered. The differential problem is reduced to the system of linear algebraic equations by applying twice the fast expansions with respect to the angular and radial coordinate. In order to determine the unknown coefficients of fast expansions, the pointwise method is utilized. The problem solution derived has explicit analytical form and it’s valid for the entire domain including its boundary. The computed profiles of the displacements and stresses in a cross-section of the cutter are provided. The stress field is investigated for various values of opening angle and cusp’s radius.

  18. Development of Cone Wedge Ring Expansion Test to Evaluate Mechanical Properties of Clad Tubing Structure

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-01

    To determine the hoop tensile properties of irradiated fuel cladding in a hot cell, a cone wedge ring expansion test method was developed. A four-piece wedge insert was designed with tapered angles matched to the cone shape of a loading piston. The ring specimen was expanded in the radial direction by the lateral expansion of the wedges under the downward movement of the piston. The advantages of the proposed method are that implementation of the test setup in a hot cell is simple and easy, and that it enables a direct strain measurement of the test specimen from the piston’s vertical displacement soon after the wedge-clad contact resistance is initiated.

  19. Radial profile of pressure in a storm ring current as a function of D st

    Science.gov (United States)

    Kovtyukh, A. S.

    2010-06-01

    Using satellite data obtained near the equatorial plane during 12 magnetic storms with amplitudes from -61 down to -422 nT, the dependences of maximum in L-profile of pressure ( L m) of the ring current (RC) on the current value of D st are constructed, and their analytical approximations are derived. It is established that function L m( D st ) is steeper on the phase of recovery than during the storm’s main phase. The form of the outer edge of experimental radial profiles of RC pressure is studied, and it is demonstrated to correspond to exponential growth of the total energy of RC particles on a given L shell with decreasing L. It is shown that during the storms’ main phase the ratio of plasma and magnetic field pressures at the RC maximum does not practically depend on the storm strength and L m value. This fact reflects resistance of the Earth’s magnetic field to RC expansion, and testifies that during storms the possibilities of injection to small L are limited for RC particles. During the storms’ recovery phase this ratio quickly increases with increasing L m, which reflects an increased fraction of plasma in the total pressure balance. It is demonstrated that function L m( D st ) is derived for the main phase of storms from the equations of drift motion of RC ions in electrical and magnetic fields, reflecting the dipole character of magnetic field and scale invariance of the pattern of particle convection near the RC maximum. For the recovery phase it is obtained from the Dessler-Parker-Sckopke relationship. The obtained regularities allow one to judge about the radial profile of RC pressure from ground-based magnetic measurements (data on the D st variation).

  20. Thermoelastic expansion in prompt-critical neutron pulse idealized in a fissile metallic sphere

    International Nuclear Information System (INIS)

    Barroso, D.E.G.; Ribeiro, S.G.

    1985-01-01

    Prompt critical pulses in solid and homogeneous spheres of enriched uranium (93%) and metallic plutonium are studied. The feedback mechanism of the negative inserted reactivity is given by the elastic expansion due to the increase of the temperature in the sphere. Thermomechanical behavior and the capability of the system to become subcritical without a very large increase of energy released in the pulse are analysed. The neutronic and thermoelasticity equations are solved in the time. (M.C.K.) [pt

  1. Application of radial basis neural network for state estimation of ...

    African Journals Online (AJOL)

    An original application of radial basis function (RBF) neural network for power system state estimation is proposed in this paper. The property of massive parallelism of neural networks is employed for this. The application of RBF neural network for state estimation is investigated by testing its applicability on a IEEE 14 bus ...

  2. Softening of the Radial Breathing Mode in Metallic Carbon Nanotubes

    Czech Academy of Sciences Publication Activity Database

    Farhat, H. (ed.); Sasaki, K.; Kalbáč, Martin; Hofmann, M.; Saito, R.; Dresselhaus, M. S.; Kong, J.

    2009-01-01

    Roč. 102, č. 12 (2009), 126804-1-126804-4 ISSN 0031-9007 Institutional research plan: CEZ:AV0Z40400503 Keywords : metallic carbon nanotubes * radial breathing mode * single waled carbon nanotubes Subject RIV: CG - Electrochemistry Impact factor: 7.328, year: 2009

  3. Transport in Silicon Nanowires: Role of Radial Dopant Profile

    DEFF Research Database (Denmark)

    Markussen, Troels; Rurali, Riccardo; Jauho, Antti-Pekka

    2008-01-01

    distributions of P dopant impurities. We find that the radial distribution of the dopants influences the conductance properties significantly: surface doped wires have longer mean-free paths and smaller sample-to-sample fluctuations in the cross-over from ballistic to diffusive transport. These findings can...

  4. Radial basis function neural network in fault detection of automotive ...

    African Journals Online (AJOL)

    Radial basis function neural network in fault detection of automotive engines. ... Five faults have been simulated on the MVEM, including three sensor faults, one component fault and one actuator fault. The three sensor faults ... Keywords: Automotive engine, independent RBFNN model, RBF neural network, fault detection

  5. Some aspects of radial flow between parallel disks

    International Nuclear Information System (INIS)

    Tabatabai, M.; Pollard, A.

    1985-01-01

    Radial flow of air between two closely spaced parallel disks is examined experimentally. A comprehensive review of the previous work performed on similar flow situations is given by Tabatabai and Pollard. The present paper is a discussion of some of the results obtained so far and offers some observations on the decay of turbulence in this flow. (author)

  6. Orthogonal bases of radial functions for charge density refinements

    International Nuclear Information System (INIS)

    Restori, R.

    1990-01-01

    Charge density determination from X-ray measurements necessitates the evaluation of the Fourier-Bessel transforms of the radial functions used to expand the charge density. Analytical expressions are given here for four sets of orthogonal functions which can substitute for the 'traditional exponential functions' set in least-squares refinements. (orig.)

  7. Effects of Radial Electric Fields on ICRF Waves

    International Nuclear Information System (INIS)

    Phillips, C.K.; Hosea, J.C.; Ono, M.; Wilson, J.R.

    2001-01-01

    Equilibrium considerations infer that large localized radial electric fields are associated with internal transport barrier structures in tokamaks and other toroidal magnetic confinement configurations. In this paper, the effects of an equilibrium electric field on fast magnetosonic wave propagation are considered in the context of a cold plasma model

  8. Space-time transformations in radial path integrals

    International Nuclear Information System (INIS)

    Steiner, F.

    1984-09-01

    Nonlinear space-time transformations in the radial path integral are discussed. A transformation formula is derived, which relates the original path integral to the Green's function of a new quantum system with an effective potential containing an observable quantum correction proportional(h/2π) 2 . As an example the formula is applied to spherical Brownian motion. (orig.)

  9. Radial Matrix Elements of Hydrogen Atom and the Correspondence ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Hydrogen excited states—radial matrix element—corres- ... atoms, its availability, production, its spectras, and importance in astrophysics (Dupree ... far away revolving lazily around in a slow orbit like a distant planet in the solar system. As the electron orbit diameter grows rapidly, its energy also decreases rapidly. Currently ...

  10. Radial tunnel syndrome. Findings and treatment in 17 patients

    Directory of Open Access Journals (Sweden)

    Gustavo Alberto Breglia

    2015-05-01

    Full Text Available Backround Radial tunnel syndrome is a condition secondary to the intermittent entrapment of the posterior interosseous nerve between superficial and deep mass of short supinator adjacent structures, such as vessels and fascias. The purpose of this study was to identify the anatomical structures that produce the eventual compression, to establish and communicate the differences in the subjective pain perception before and after the release of the posterior interosseous nerve in the radial tunnel. Method Between 2009 and 2014, 17 patients underwent surgical treatment by posterior interosseous nerve release. We used the approach between the first external radial and brachioradialis. Patients were assessed by visual analogue scale for pain intensity before surgery and at week 6, and according to the Roles and Maudsley functional criteria. Results The causes of posterior interosseous nerve compression were fibrous band of short supinator (arcade of Frohse (7 cases, recurrent vessels (4 cases, compression by the mass of the superficial portion of the short supinator muscle (2 cases and secondary compression by extensor carpi radialis brevis tendon (4 cases. Results were excellent (4 patients, good (10 patients and fair (3 patients. Patients treated through the Labor Risk Insurance had worse outcomes than those who were not covered by this system. Conclusions Radial tunnel syndrome is a condition that must be taken into account when there is refractory lateral epicondylalgia. This disease has a marked effect in patients with labor conflict, which may bias the outcome of treatment.

  11. Radial Basis Function Based Quadrature over Smooth Surfaces

    Science.gov (United States)

    2016-03-24

    Radial Basis Functions φ(r) Piecewise Smooth (Conditionally Positive Definite) MN Monomial |r|2m+1 TPS thin plate spline |r|2mln|r| Infinitely Smooth...smooth surfaces using polynomial interpolants, while [27] couples Thin - Plate Spline interpolation (see table 1) with Green’s integral formula [29

  12. Clinical Presentation, Surgical Treatment, and Outcome in Radial Polydactyly.

    Science.gov (United States)

    Dijkman, R R; van Nieuwenhoven, C A; Hovius, S E R; Hülsemann, W

    2016-02-01

    Radial polydactyly or 'thumb duplication' is the most common congenital upper limb anomaly ('CULA') affecting the thumb. The clinical presentation is highly diverse, ranging from an extra thumb floating on a skin bridge to complicated thumb triplications with triphalangeal, deviating, and hypoplastic components. Radial polydactyly can be classified into one of 7 osseous presentations using the Wassel classification, with type IV (45%), type II (20%), and type VII (15%) occurring most frequently. When faced with a radial polydactyly case, hand surgeons specialised in congenital anomalies must weigh the preoperative functional potential and degree of hypoplasia of both thumbs in order to decide whether to resect one thumb and reconstruct the other ('resection and reconstruction'), excise a central part of both thumbs and unite the lateral tissues into one thumb ('the Bilhaut procedure'), transfer the better-developed distal tissues of one thumb onto the better-developed proximal tissues of the other ('on-top plasty'), or discard both severely hypoplastic thumbs and pollicise the index finger. Mere excision of the hypoplastic thumb is rarely indicated since it often requires subsequent revision surgery. Even after being treated by experienced surgeons, about 15% of patients with polydactyly will need additional procedures to correct residual and/or new problems such as deviation from the longitudinal axis and joint instability. Nevertheless, radial polydactyly patients usually achieve unimpaired everyday hand function postoperatively. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Coherence of Radial Implicative Fuzzy Systems with Nominal Consequents

    Czech Academy of Sciences Publication Activity Database

    Coufal, David

    -, č. 4 (2006), s. 60-66 ISSN 1509-4553 R&D Projects: GA MŠk 1M0545 Institutional research plan: CEZ:AV0Z10300504 Keywords : implicative fuzzy system * radial fuzzy system * nominal output space * coherence Subject RIV: IN - Informatics, Computer Science

  14. Radial oscillations of neutron stars in strong magnetic fields

    Indian Academy of Sciences (India)

    The eigen frequencies of radial pulsations of neutron stars are calculated in a strong magnetic field. At low densities we use the magnetic BPS equation of state (EOS) similar to that obtained by Lai and Shapiro while at high densities the EOS obtained from the relativistic nuclear mean field theory is taken and extended to ...

  15. Classification of EEG Signals by Radial Neuro-Fuzzy Systems

    Czech Academy of Sciences Publication Activity Database

    Coufal, David

    2006-01-01

    Roč. 5, č. 2 (2006), s. 415-423 ISSN 1109-2777 R&D Projects: GA MŠk ME 701 Institutional research plan: CEZ:AV0Z10300504 Keywords : neuro-fuzzy systems * radial fuzzy systems * data mining * hybrid systems Subject RIV: BA - General Mathematics

  16. Radial Transport and Meridional Circulation in Accretion Disks

    Energy Technology Data Exchange (ETDEWEB)

    Philippov, Alexander A. [Department of Astrophysical Sciences, Princeton University, Ivy Lane, Princeton, NJ 08540 (United States); Rafikov, Roman R., E-mail: sashaph@princeton.edu [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)

    2017-03-10

    Radial transport of particles, elements and fluid driven by internal stresses in three-dimensional (3D) astrophysical accretion disks is an important phenomenon, potentially relevant for the outward dust transport in protoplanetary disks, origin of the refractory particles in comets, isotopic equilibration in the Earth–Moon system, etc. To gain better insight into these processes, we explore the dependence of meridional circulation in 3D disks with shear viscosity on their thermal stratification, and demonstrate a strong effect of the latter on the radial flow. Previous locally isothermal studies have normally found a pattern of the radial outflow near the midplane, switching to inflow higher up. Here we show, both analytically and numerically, that a flow that is inward at all altitudes is possible in disks with entropy and temperature steeply increasing with height. Such thermodynamic conditions may be typical in the optically thin, viscously heated accretion disks. Disks in which these conditions do not hold should feature radial outflow near the midplane, as long as their internal stress is provided by the shear viscosity. Our results can also be used for designing hydrodynamical disk simulations with a prescribed pattern of the meridional circulation.

  17. Simple overlay device for determining radial head and neck height

    International Nuclear Information System (INIS)

    Moon, Jun-Gyu; Southgate, Richard D.; Fitzsimmons, James S.; O'Driscoll, Shawn W.

    2010-01-01

    The purpose of this study was to test the hypothesis that a simple overlay device can be used on radiographs to measure radial head and neck height. Thirty anteroposterior elbow radiographs from 30 patients with a clinical diagnosis of lateral epicondylitis were examined to measure radial head and neck height. Three methods using different points along the bicipital tuberosity as a landmark were used. Method 1 used the proximal end of the bicipital tuberosity, method 2 used the most prominent point of the bicipital tuberosity, and method 3 used a simple overlay device (SOD) template that was aligned with anatomic reference points. All measurements were performed three times by three observers to determine interobserver and intraobserver reliability. Intraclass correlation coefficients revealed higher interobserver and intraobserver correlations for the SOD template method than for the other two methods. The 95% limits of agreement between observers were markedly better (-1.8 mm to +1.0 mm) for the SOD template method than for the proximal point method (-3.8 mm to +3.4 mm) or the prominent point method (-5.9 mm to +4.9 mm). We found that the SOD template method was reliable for assessing radial head and neck height. It had less variability than other methods, its 95% limit of agreement being less than 2 mm. This method could be helpful for assessing whether or not the insertion of a radial head prosthesis has resulted in over-lengthening of the radius. (orig.)

  18. Modelling and analysis of radial thermal stresses and temperature ...

    African Journals Online (AJOL)

    user

    it acts as an insulating medium and prevents the heat flow, hence the need of providing insulation coating on valves is ... geometry metal components (piston, liner and cylinder head) and found a satisfactory .... model. Step8: Find the radial thermal stress at all the nodal point with the use of temperature ..... Cast iron St. 70.

  19. Vascularised Fibular Graft for a Radial Defect following Tumour ...

    African Journals Online (AJOL)

    HP

    The mass was located on the radial aspect of the distal right ... modification, internal or external fixation with bone grafting, structural grafts of ... Our index case report demonstrates that free vascularized fibular graft transfer is a feasible option ... structural support, the potential for graft hypertrophy, relative resistance to ...

  20. Surface interpolation with radial basis functions for medical imaging

    International Nuclear Information System (INIS)

    Carr, J.C.; Beatson, R.K.; Fright, W.R.

    1997-01-01

    Radial basis functions are presented as a practical solution to the problem of interpolating incomplete surfaces derived from three-dimensional (3-D) medical graphics. The specific application considered is the design of cranial implants for the repair of defects, usually holes, in the skull. Radial basis functions impose few restrictions on the geometry of the interpolation centers and are suited to problems where interpolation centers do not form a regular grid. However, their high computational requirements have previously limited their use to problems where the number of interpolation centers is small (<300). Recently developed fast evaluation techniques have overcome these limitations and made radial basis interpolation a practical approach for larger data sets. In this paper radial basis functions are fitted to depth-maps of the skull's surface, obtained from X-ray computed tomography (CT) data using ray-tracing techniques. They are used to smoothly interpolate the surface of the skull across defect regions. The resulting mathematical description of the skull's surface can be evaluated at any desired resolution to be rendered on a graphics workstation or to generate instructions for operating a computer numerically controlled (CNC) mill

  1. Simple overlay device for determining radial head and neck height

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Jun-Gyu; Southgate, Richard D.; Fitzsimmons, James S.; O' Driscoll, Shawn W. [Mayo Clinic, Department of Orthopaedic Surgery, Rochester, MN (United States)

    2010-09-15

    The purpose of this study was to test the hypothesis that a simple overlay device can be used on radiographs to measure radial head and neck height. Thirty anteroposterior elbow radiographs from 30 patients with a clinical diagnosis of lateral epicondylitis were examined to measure radial head and neck height. Three methods using different points along the bicipital tuberosity as a landmark were used. Method 1 used the proximal end of the bicipital tuberosity, method 2 used the most prominent point of the bicipital tuberosity, and method 3 used a simple overlay device (SOD) template that was aligned with anatomic reference points. All measurements were performed three times by three observers to determine interobserver and intraobserver reliability. Intraclass correlation coefficients revealed higher interobserver and intraobserver correlations for the SOD template method than for the other two methods. The 95% limits of agreement between observers were markedly better (-1.8 mm to +1.0 mm) for the SOD template method than for the proximal point method (-3.8 mm to +3.4 mm) or the prominent point method (-5.9 mm to +4.9 mm). We found that the SOD template method was reliable for assessing radial head and neck height. It had less variability than other methods, its 95% limit of agreement being less than 2 mm. This method could be helpful for assessing whether or not the insertion of a radial head prosthesis has resulted in over-lengthening of the radius. (orig.)

  2. Control of radial electric field in torus plasma

    International Nuclear Information System (INIS)

    Ida, K.; Idei, H.; Sanuki, H.

    1994-09-01

    The radial electric fields is controlled by changing the direction of neutral beam from co to counter to plasma current in tokamak, while it is controlled by the 2nd harmonic ECH and NBI and pellet injection in heliotron/torsatron. (author)

  3. Radial solutions to semilinear elliptic equations via linearized operators

    Directory of Open Access Journals (Sweden)

    Phuong Le

    2017-04-01

    Full Text Available Let $u$ be a classical solution of semilinear elliptic equations in a ball or an annulus in $\\mathbb{R}^N$ with zero Dirichlet boundary condition where the nonlinearity has a convex first derivative. In this note, we prove that if the $N$-th eigenvalue of the linearized operator at $u$ is positive, then $u$ must be radially symmetric.

  4. Press-fit bipolar radial head arthroplasty, midterm results

    NARCIS (Netherlands)

    Kodde, Izaäk F.; Heijink, Andras; Kaas, Laurens; Mulder, Paul G. H.; van Dijk, C. Niek; Eygendaal, Denise

    2016-01-01

    Theoretical advantages of bipolar compared with monopolar radial head arthroplasty include better accommodation of radiocapitellar malalignment, reduction of capitellar abrasion, and reduction of stress at the bone-implant interfaces. Our purpose was to report the midterm results of press-fit

  5. Isolated posterior dislocation of the radial head in an adult.

    Directory of Open Access Journals (Sweden)

    Negi A

    1992-07-01

    Full Text Available Isolated posterior dislocation of the radial head was detected on X-ray in a patient following a vehicular accident. Such a dislocation without an associated fracture is extremely rare in adults. Immobilization of the elbow in full pronation and 90 degrees flexion for 4 weeks normalized the position of the head of the radius.

  6. Rayleigh-Taylor instability of cylindrical jets with radial motion

    International Nuclear Information System (INIS)

    Chen, X.M.; Schrock, V.E.; Peterson, P.F.

    1997-01-01

    Rayleigh-Taylor instability of an interface between fluids with different densities subjected to acceleration normal to itself has interested researchers for almost a century. The classic analyses of a flat interface by Rayleigh and Taylor have shown that this type of instability depends on the direction of acceleration and the density differences of the two fluids. Plesset later analyzed the stability of a spherically symmetric flows (and a spherical interface) and concluded that the instability also depends on the velocity of the interface as well as the direction and magnitude of radial acceleration. The instability induced by radial motion in cylindrical systems seems to have been neglected by previous researchers. This paper analyzes the Rayleigh-Taylor type of instability for a cylindrical surface with radial motions. The results of the analysis show that, like the spherical case, the radial velocity also plays an important role. As an application, the example of a liquid jet surface in an Inertial Confinement Fusion (ICF) reactor design is analyzed. (orig.)

  7. Vertical, radial and drag force analysis of superconducting magnetic bearings

    International Nuclear Information System (INIS)

    Cansiz, Ahmet

    2009-01-01

    The behavior of the force between a permanent magnet (PM) and a high temperature superconductor (HTS) was tested with the frozen-image model based on flux pinning. It was found that the associated dipole moment assumptions of the method of the frozen image underestimate the force somewhat; thus a quadrupole moment analysis is proposed. The radial and drag forces associated with the rotation of the PM levitated above the HTS were measured by using a force transducer and by means of a cantilevered beam technique. The radial force was found not to be dependent on the radial direction, and the least radial force was found to be periodic with an angular displacement during the slow rotation of the PM relative to the HTS. The periodicity behavior of the force is attributed to the geometric eccentricity from the magnetization distribution of the PM and HTS. The drag force associated with the torsional stiffness of the levitated PM during the low and high rotational speeds was incorporated with the data from the literature.

  8. Radial electron beam laser excitation: the REBLE report

    International Nuclear Information System (INIS)

    Ramirez, J.J.; Prestwich, K.R.

    1978-10-01

    The results of an investigation of techniques to generate high-power radially converging electron beams and the application of these beams to gas lasers is discussed. The design and performance of the REBLE accelerator that was developed for this program is presented. Reliable operation of the radial diode has been obtained at levels up to 1 MV, 200 kA, and 20 ns. It has been demonstrated that the anode current density can be made uniform to better than 15% over 1000 cm 2 areas with 100 to 250 A/cm 2 intensities. The measured total and spatially resolved energy deposition of this radial electron beam in various gases is compared with Monte Carlo calculations. In most cases, these codes give an accurate description of the beam transport and energy deposition. With the electron beam pumping xenon gas, the amplitude of xenon excimer radiation (1720 A 0 ) was radially uniform to within the experimental uncertainty. The efficiency of converting deposited electron beam energy to xenon excimer radiation was 20%

  9. Radial mode structure of curvature-driven instabilities in EBT

    International Nuclear Information System (INIS)

    Spong, D.A.

    1983-01-01

    Viewgraphs describe the theoretical treatment of the radial mode structure of plasma instabilities in the Elmo Bumpy Torus. The calculation retains nonlocal structure of the modes, connects inner and outer ring regions together, uses a self-consistent finite β, includes the relativistic effects for the hot electron ring, and examines a wide range of parameters

  10. On radio frequency wave induced radial transport and wave helicity

    International Nuclear Information System (INIS)

    Petrzilka, V.

    1992-09-01

    Expressions for wave induced radial transport are derived allowing simple estimates. The transport is enhanced due to the presence of poloidal magnetostatic field and in the vicinity of the ion cyclotron resonance. The direction of the wave induced transport depends also on the wave polarization. (author) 19 refs

  11. Non Radial Oscillations in an Axisymmetric MHD Incompressible Fluid

    Indian Academy of Sciences (India)

    tribpo

    Abstract. It is well known from Helioseismology that the Sun exhibits oscillations on a global scale, most of which are non radial in nature. These oscillations help us to get a clear picture of the internal structure of the Sun as has been demonstrated by the theoretical and observational. (such as GONG) studies. In this study ...

  12. Analysis of radial vibrations of poroelastic circular cylindrical shells ...

    African Journals Online (AJOL)

    DR OKE

    vanished, the considered problem reduces to the problem of radial vibrations of fluid-filled poroelastic circular cylindrical shell. (2). When the .... the volume change of the solid to that of liquid. ..... When the outer fluid density is zero, that is, ρof = 0 then the poroelastic cylindrical shell immersed in an acoustic medium will.

  13. Drying and radial shrinkage characteristics and changes in color ...

    African Journals Online (AJOL)

    Drying and radial shrinkage characteristics and changes in color and shape of carrots tissues during air drying were studied. Slices dimensions were obtained by computer vision and the color was quantified by chroma, hue, whitening index and total carotenoids contents. The drying time became shorter of 1 h when ...

  14. Hubble expansion in static spacetime

    International Nuclear Information System (INIS)

    Rossler, Otto E.; Froehlich, Dieter; Movassagh, Ramis; Moore, Anthony

    2007-01-01

    A recently proposed mechanism for light-path expansion in a static spacetime is based on the moving-lenses paradigm. Since the latter is valid independently of whether space expands or not, a static universe can be used to better see the implications. The moving-lenses paradigm is related to the paradigm of dynamical friction. If this is correct, a Hubble-like law is implicit. It is described quantitatively. A bent in the Hubble-like line is predictably implied. The main underlying assumption is Price's Principle (PI 3 ). If the theory is sound, the greatest remaining problem in cosmology becomes the origin of hydrogen. Since Blandford's jet production mechanism for quasars is too weak, a generalized Hawking radiation hidden in the walls of cosmic voids is invoked. A second prediction is empirical: slow pattern changes in the cosmic microwave background. A third is ultra-high redshifts for Giacconi quasars. Bruno's eternal universe in the spirit of Augustine becomes a bit less outlandish

  15. Primordial vorticity and gradient expansion

    CERN Document Server

    Giovannini, Massimo

    2012-01-01

    The evolution equations of the vorticities of the electrons, ions and photons in a pre-decoupling plasma are derived, in a fully inhomogeneous geometry, by combining the general relativistic gradient expansion and the drift approximation within the Adler-Misner-Deser decomposition. The vorticity transfer between the different species is discussed in this novel framework and a set of general conservation laws, connecting the vorticities of the three-component plasma with the magnetic field intensity, is derived. After demonstrating that a source of large-scale vorticity resides in the spatial gradients of the geometry and of the electromagnetic sources, the total vorticity is estimated to lowest order in the spatial gradients and by enforcing the validity of the momentum constraint. By acknowledging the current bounds on the tensor to scalar ratio in the (minimal) tensor extension of the $\\Lambda$CDM paradigm the maximal comoving magnetic field induced by the total vorticity turns out to be, at most, of the or...

  16. Clinical Outcomes following median to radial nerve transfers

    Science.gov (United States)

    Ray, Wilson Z.; Mackinnon, Susan E.

    2010-01-01

    Purpose In this study the authors evaluate the clinical outcomes in patients with radial nerve palsy who underwent nerve transfers utilizing redundant fascicles of median nerve (innervating the flexor digitorum superficialis and flexor carpi radialis muscles) to the posterior interosseous nerve and the nerve to the extensor carpi radialis brevis. Methods A retrospective review of the clinical records of 19 patients with radial nerve injuries who underwent nerve transfer procedures using the median nerve as a donor nerve were included. All patients were evaluated using the Medical Research Council (MRC) grading system. Results The mean age of patients was 41 years (range 17 – 78 years). All patients received at least 12 months of follow-up (20.3 ± 5.8 months). Surgery was performed at a mean of 5.7 ± 1.9 months post-injury. Post-operative functional evaluation was graded according to the following scale: grades MRC 0/5 - MRC 2/5 were considered poor outcomes, while MRC of 3/5 was a fair result, MRC grade 4/5 was a good result, and grade 4+/5 was considered an excellent outcome. Seventeen patients (89%) had a complete radial nerve palsy while two patients (11%) had intact wrist extension but no finger or thumb extension. Post-operatively all patients except one had good to excellent recovery of wrist extension. Twelve patients recovered good to excellent finger and thumb extension, two patients had fair recovery, five patients had a poor recovery. Conclusions The radial nerve is a commonly injured nerve, causing significant morbidity in affected patients. The median nerve provides a reliable source of donor nerve fascicles for radial nerve reinnervation. This transfer was first performed in 1999 and evolved over the subsequent decade. The important nuances of both surgical technique and motor re-education critical for to the success of this transfer have been identified and are discussed. PMID:21168979

  17. Radial scars detected mammographically in a breast cancer screening programme

    International Nuclear Information System (INIS)

    Azavedo, E.; Svane, G.

    1992-01-01

    Radial scars are getting more and more common since implementation of mammography as diagnostic tool in screening women for breast cancer. At Karolinska Hospital, 18987 asymptomatic women, aged 50-69, were screened for breast cancer through mammography during August 1989-May 1991. A total of 735 (3.87%) were recalled for additional views after initial mammograms and 463 (2.44%) were assessed with help of cytology. In all 175 women (0.92%) were selected for surgery and 146 (0.77%) had histologically verified cancers. The remaining 29 (0.15%) had non- malignant lesions of which 11 (0.06%) were radial scars. All radial scars were diagnosed on mammograms and later confirmed with histology. The radiologic characteristics were found to be a) rather thick and long radiating structures accompanied by radiolucent linear structures parallel to some of the spicules, b) absence of calcifications, c) radiolucent areas in the body of the lesion, d) an average mean size of 6 mm and e) changing image in different views. Most of the lesions, 73% (8/11), were in moderately dense breasts and there was no specific relation to the right or left breast. A majority of radial scars, 64% (7/11), were found in the upper outer quadrants, 3/11 in the lower outer quadrants and 1/11 in the lower inner quadrant. Literature shows that histology uses many synonyms for radial scars and therefore team work between radiologists and pathologists is suggested for better conformity of the diagnosis. (author). 32 refs.; 1 fig

  18. Reactive Power from Distributed Energy

    Energy Technology Data Exchange (ETDEWEB)

    Kueck, John; Kirby, Brendan; Rizy, Tom; Li, Fangxing; Fall, Ndeye

    2006-12-15

    Distributed energy is an attractive option for solving reactive power and distribution system voltage problems because of its proximity to load. But the cost of retrofitting DE devices to absorb or produce reactive power needs to be reduced. There also needs to be a market mechanism in place for ISOs, RTOs, and transmission operators to procure reactive power from the customer side of the meter where DE usually resides. (author)

  19. Reactive Power from Distributed Energy

    International Nuclear Information System (INIS)

    Kueck, John; Kirby, Brendan; Rizy, Tom; Li, Fangxing; Fall, Ndeye

    2006-01-01

    Distributed energy is an attractive option for solving reactive power and distribution system voltage problems because of its proximity to load. But the cost of retrofitting DE devices to absorb or produce reactive power needs to be reduced. There also needs to be a market mechanism in place for ISOs, RTOs, and transmission operators to procure reactive power from the customer side of the meter where DE usually resides. (author)

  20. Reactive programming in eventsourcing systems

    OpenAIRE

    Kučinskas, Žilvinas

    2017-01-01

    Eventsourcing describes current state as series of events that occurred in a system. Events hold all information that is needed to recreate current state. This method allows to achieve high volume of transactions, and enables efficient replication. Whereas reactive programming lets implement reactive systems in declarative style, decomposing logic into smaller, easier to understand components. Thesis aims to create reactive programming program interface, incorporating both principles. Applyin...

  1. Reactive Programming in Standard ML

    OpenAIRE

    Pucella, Riccardo

    2004-01-01

    Reactive systems are systems that maintain an ongoing interaction with their environment, activated by receiving input events from the environment and producing output events in response. Modern programming languages designed to program such systems use a paradigm based on the notions of instants and activations. We describe a library for Standard ML that provides basic primitives for programming reactive systems. The library is a low-level system upon which more sophisticated reactive behavi...

  2. Positive void reactivity

    International Nuclear Information System (INIS)

    Diamond, D.J.

    1992-09-01

    This report is a review of some of the important aspects of the analysis of large loss-of-coolant accidents (LOCAs). One important aspect is the calculation of positive void reactivity. To study this subject the lattice physics codes used for void worth calculations and the coupled neutronic and thermal-hydraulic codes used for the transient analysis are reviewed. Also reviewed are the measurements used to help validate the codes. The application of these codes to large LOCAs is studied with attention focused on the uncertainty factor for the void worth used to bias the results. Another aspect of the subject dealt with in the report is the acceptance criteria that are applied. This includes the criterion for peak fuel enthalpy and the question of whether prompt criticality should also be a criterion. To study the former, fuel behavior measurements and calculations are reviewed. (Author) (49 refs., 2 figs., tab.)

  3. Massive florid reactive periostitis

    International Nuclear Information System (INIS)

    Nance, K.V.; Renner, J.B.; Brashear, H.R.; Siegal, G.P.; North Carolina Univ., Chapel Hill, NC

    1990-01-01

    Florid reactive periostitis is a rare, benign process usually occurring in the small, tubular bones of the hands and feet. Typically the lesion occurs in an adolescent or young adult and presents as a small area of pain and erythema over the affected bone. Although the histologic features may suggest malignancy, there is usually little radiographic evidence to support such a diagnosis. In the following report an unusual example of this entity is described whose large size and relentless local progression led to initial diagnostic uncertainty and eventual aggressive management. This case suggests that a wide spectrum of radiologic and morphologic changes may be seen in this entity and that a seemingly unrelated genetic disease may alter the typical clinical course. (orig.)

  4. Pembrolizumab reactivates pulmonary granulomatosis

    Directory of Open Access Journals (Sweden)

    Majdi Al-dliw

    2017-01-01

    Full Text Available Sarcoid like reaction is a well-known entity that occurs as a consequence to several malignancies or their therapies. Immunotherapy has gained a lot of interest in the past few years and has recently gained approval as first line therapy in multiple advanced stage malignancies. Pneumonitis has been described as complication of such therapy. Granulomatous inflammation has been only rarely reported subsequent to immunotherapy. We describe a case of granulomatous inflammation reactivation affecting the lungs in a patient previously exposed to Pembrolizumab and have evidence of a distant granulomatous infection. We discuss potential mechanisms of the inflammation and assert the importance of immunosuppression in controlling the dis-inhibited immune system.

  5. Reactive Oxygen Species

    DEFF Research Database (Denmark)

    Franchina, Davide G.; Dostert, Catherine; Brenner, Dirk

    2018-01-01

    T cells are a central component of defenses against pathogens and tumors. Their effector functions are sustained by specific metabolic changes that occur upon activation, and these have been the focus of renewed interest. Energy production inevitably generates unwanted products, namely reactive...... and transcription factors, influencing the outcome of the T cell response. We discuss here how ROS can directly fine-tune metabolism and effector functions of T cells....... oxygen species (ROS), which have long been known to trigger cell death. However, there is now evidence that ROS also act as intracellular signaling molecules both in steady-state and upon antigen recognition. The levels and localization of ROS contribute to the redox modeling of effector proteins...

  6. Intense passionate love attenuates cigarette cue-reactivity in nicotine-deprived smokers: an FMRI study.

    Directory of Open Access Journals (Sweden)

    Xiaomeng Xu

    Full Text Available Self-expanding experiences like falling in love or engaging in novel, exciting and interesting activities activate the same brain reward mechanism (mesolimbic dopamine pathway that reinforces drug use and abuse, including tobacco smoking. This suggests the possibility that reward from smoking is substitutable by self-expansion (through competition with the same neural system, potentially aiding cessation efforts. Using a model of self-expansion in the context of romantic love, the present fMRI experiment examined whether, among nicotine-deprived smokers, relationship self-expansion is associated with deactivation of cigarette cue-reactivity regions. Results indicated that among participants who were experiencing moderate levels of craving, cigarette cue-reactivity regions (e.g., cuneus and posterior cingulate cortex showed significantly less activation during self-expansion conditions compared with control conditions. These results provide evidence that rewards from one domain (self-expansion can act as a substitute for reward from another domain (nicotine to attenuate cigarette cue reactivity.

  7. Intense passionate love attenuates cigarette cue-reactivity in nicotine-deprived smokers: an FMRI study.

    Science.gov (United States)

    Xu, Xiaomeng; Wang, Jin; Aron, Arthur; Lei, Wei; Westmaas, J Lee; Weng, Xuchu

    2012-01-01

    Self-expanding experiences like falling in love or engaging in novel, exciting and interesting activities activate the same brain reward mechanism (mesolimbic dopamine pathway) that reinforces drug use and abuse, including tobacco smoking. This suggests the possibility that reward from smoking is substitutable by self-expansion (through competition with the same neural system), potentially aiding cessation efforts. Using a model of self-expansion in the context of romantic love, the present fMRI experiment examined whether, among nicotine-deprived smokers, relationship self-expansion is associated with deactivation of cigarette cue-reactivity regions. Results indicated that among participants who were experiencing moderate levels of craving, cigarette cue-reactivity regions (e.g., cuneus and posterior cingulate cortex) showed significantly less activation during self-expansion conditions compared with control conditions. These results provide evidence that rewards from one domain (self-expansion) can act as a substitute for reward from another domain (nicotine) to attenuate cigarette cue reactivity.

  8. Weigle Reactivation in Acinetobacter Calcoaceticus

    DEFF Research Database (Denmark)

    Berenstein, Dvora

    1982-01-01

    phage and host survivals of about 5 times 10-6 and 1 times 10-1, respectively. Intracellular development of W-reactivated P78 was followed by one-step growth experiments. Conditions which allowed maximal W-reactivation also extended the period of phage production and yielded a somewhat reduced burst......Weigle (W)-reactivation was demonstrated in Acinetobacter calcoaceticus for the UV-irra-diated lysogenic phage P78. The reactivation factor (survival of irradiated phage on irradiated bacteria/ survival on unirradiated bacteria) reached a maximum value of 20. This was obtained at UV-doses giving...

  9. Negative thermal expansion materials: technological key for control of thermal expansion

    OpenAIRE

    Koshi Takenaka

    2012-01-01

    Most materials expand upon heating. However, although rare, some materials contract upon heating. Such negative thermal expansion (NTE) materials have enormous industrial merit because they can control the thermal expansion of materials. Recent progress in materials research enables us to obtain materials exhibiting negative coefficients of linear thermal expansion over −30 ppm K−1. Such giant NTE is opening a new phase of control of thermal expansion in composites. Specifically examining pra...

  10. Optimization design of energy deposition on single expansion ramp nozzle

    Science.gov (United States)

    Ju, Shengjun; Yan, Chao; Wang, Xiaoyong; Qin, Yupei; Ye, Zhifei

    2017-11-01

    Optimization design has been widely used in the aerodynamic design process of scramjets. The single expansion ramp nozzle is an important component for scramjets to produces most of thrust force. A new concept of increasing the aerodynamics of the scramjet nozzle with energy deposition is presented. The essence of the method is to create a heated region in the inner flow field of the scramjet nozzle. In the current study, the two-dimensional coupled implicit compressible Reynolds Averaged Navier-Stokes and Menter's shear stress transport turbulence model have been applied to numerically simulate the flow fields of the single expansion ramp nozzle with and without energy deposition. The numerical results show that the proposal of energy deposition can be an effective method to increase force characteristics of the scramjet nozzle, the thrust coefficient CT increase by 6.94% and lift coefficient CN decrease by 26.89%. Further, the non-dominated sorting genetic algorithm coupled with the Radial Basis Function neural network surrogate model has been employed to determine optimum location and density of the energy deposition. The thrust coefficient CT and lift coefficient CN are selected as objective functions, and the sampling points are obtained numerically by using a Latin hypercube design method. The optimized thrust coefficient CT further increase by 1.94%, meanwhile, the optimized lift coefficient CN further decrease by 15.02% respectively. At the same time, the optimized performances are in good and reasonable agreement with the numerical predictions. The findings suggest that scramjet nozzle design and performance can benefit from the application of energy deposition.

  11. Two satellite study of substorm expansion near geosynchronous orbit

    Directory of Open Access Journals (Sweden)

    Ø. Holter

    2004-12-01

    Full Text Available During several time intervals in 1979–1980 the satellites GEOS-2 and SCATHA were situated relatively close on the nightside of the Earth at geosynchronous distances. Several substorm events were identified during these periods. The event considered in this paper was recorded on 22 May 1979, when the satellites were separated by less than 30min in local time around 21:00 LT. The observed 45 to 60 s delay of magnetic signatures observed at the two s/c indicates a westward expansion of ~7.7°/min. At the two s/c, the magnetic signatures are, in particular for the azimuthal magnetic field components, quite different. At GEOS-2, being close to the magnetic equator, the dominant feature is a dipolarization with a weak field-aligned current signature corresponding to a symmetric current which cancels at the equator. On SCATHA, however, being close to the current sheet boundary, the azimuthal magnetic field indicates a strong field-aligned Birkeland current structure. On both s/c the first indication of an approaching substorm was an increase in the high energy ion flux followed by a reduction in the flux intensity of energetic electrons and a further tailward stretching of the magnetic field, starting ~2min before the onset of the magnetic field dipolarization. The tailward stretching, the observed variations of the magnetic field components, and the subsequent dipolarization are interpreted in terms of an azimuthally tilted field-aligned current system passing the s/c on the tailward side from east to west. The westward expansion and dipolarization observed at the two s/c are consistent with the propagation of a Rayleigh-Taylor type instability. The increased radial ion flux corresponds to the ExB-drift due to the substorm associated electric field.

    Key words. Magnetospheric physics (storms and substorms; plasma waves and instabilities; current systems

  12. Finnish Higher Education Expansion and Regional Policy

    Science.gov (United States)

    Saarivirta, Toni

    2010-01-01

    This paper concentrates on the expansion of Finnish higher education between the 1960s and 1970s, exposes its background in the light of the policy decisions that were made, compares the unique features of this expansion with those of certain other countries, discusses the impact of the controlled "top down" governance of higher…

  13. The δ expansion for stochastic quantization

    International Nuclear Information System (INIS)

    Bender, C.M.; Cooper, F.; Milton, K.A.; Department of Physics, Brown University, Providence, Rhode Island 02912; Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexic o 87545; Department of Physics, The Ohio State University, Columbus, Ohio 43210; Department of Physics and Astronomy, University of Oklahoma, Norman, Oklaho ma 73019)

    1989-01-01

    Using a recently proposed perturbation expansion called the δ expansion, we show how to solve the Langevin equation associated with a gphi 4 field theory. We illustrate the technique in zero- and one-dimensional space-time, and then generalize this approach to d dimensions

  14. The heavy quark expansion of QCD

    International Nuclear Information System (INIS)

    Falk, A.F.

    1997-01-01

    These lectures contain an elementary introduction to heavy quark symmetry and the heavy quark expansion. Applications such as the expansion of heavy meson decay constants and the treatment of inclusive and exclusive semileptonic B decays are included. Heavy hadron production via nonperturbative fragmentation processes is also discussed. 54 refs., 7 figs

  15. The heavy quark expansion of QCD

    Energy Technology Data Exchange (ETDEWEB)

    Falk, A.F. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Physics and Astronomy

    1997-06-01

    These lectures contain an elementary introduction to heavy quark symmetry and the heavy quark expansion. Applications such as the expansion of heavy meson decay constants and the treatment of inclusive and exclusive semileptonic B decays are included. Heavy hadron production via nonperturbative fragmentation processes is also discussed. 54 refs., 7 figs.

  16. Thermal expansion of doped lanthanum gallates

    Indian Academy of Sciences (India)

    Administrator

    Since the components are in intimate mechanical contact, any stress generated due to their thermal expansion mis- match during thermal cycling could lead to catastrophic failure of the cell. The functional materials must have similar thermal expansions to avoid mechanical stresses. Hence it is useful to study the thermal ...

  17. Platform Expansion Design as Strategic Choice

    DEFF Research Database (Denmark)

    Staykova, Kalina S.; Damsgaard, Jan

    2016-01-01

    In this paper, we address how the strategic choice of platform expansion design impacts the subse-quent platform strategy. We identify two distinct approaches to platform expansion – platform bun-dling and platform constellations, which currently co-exist. The purpose of this paper is to outline...

  18. Series expansion of the modified Einstein Procedure

    Science.gov (United States)

    Seema Chandrakant Shah-Fairbank

    2009-01-01

    This study examines calculating total sediment discharge based on the Modified Einstein Procedure (MEP). A new procedure based on the Series Expansion of the Modified Einstein Procedure (SEMEP) has been developed. This procedure contains four main modifications to MEP. First, SEMEP solves the Einstein integrals quickly and accurately based on a series expansion. Next,...

  19. Radial and humeral fractures as predictors of subsequent hip, radial or humeral fractures in women, and their seasonal variation

    DEFF Research Database (Denmark)

    Lauritzen, J B; Schwarz, Peter; McNair, P

    1993-01-01

    Hip fractures are common in elderly women, and early risk assessment of future hip fractures is relevant in relation to prevention. We studied the predictive value of radial and humeral fractures in women. The influence of weather conditions on the risk was also studied. Women aged 20-99 years...

  20. Maxwell superalgebras and Abelian semigroup expansion

    Directory of Open Access Journals (Sweden)

    P.K. Concha

    2014-09-01

    Full Text Available The Abelian semigroup expansion is a powerful and simple method to derive new Lie algebras from a given one. Recently it was shown that the S-expansion of so(3,2 leads us to the Maxwell algebra M. In this paper we extend this result to superalgebras, by proving that different choices of abelian semigroups S lead to interesting D=4 Maxwell Superalgebras. In particular, the minimal Maxwell superalgebra sM and the N-extended Maxwell superalgebra sM(N recently found by the Maurer–Cartan expansion procedure, are derived alternatively as an S-expansion of osp(4|N. Moreover, we show that new minimal Maxwell superalgebras type sMm+2 and their N-extended generalization can be obtained using the S-expansion procedure.