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Sample records for gyromagnetic radius

  1. Rotating spacetimes with asymptotic nonflat structure and the gyromagnetic ratio

    NASA Astrophysics Data System (ADS)

    Aliev, Alikram N.

    2008-02-01

    In general relativity, the gyromagnetic ratio for all stationary, axisymmetric, and asymptotically flat Einstein-Maxwell fields is known to be g=2. In this paper, we continue our previous works of examination of this result for rotating charged spacetimes with asymptotic nonflat structure. We first consider two instructive examples of these spacetimes: The spacetime of a Kerr-Newman black hole with a straight cosmic string on its axis of symmetry and the Kerr-Newman Taub-NUT (Newman-Unti-Tamburino) spacetime. We show that for both spacetimes the gyromagnetic ratio g=2 independent of their asymptotic structure. We also extend this result to a general class of metrics which admit separation of variables for the Hamilton-Jacobi and wave equations. We proceed with the study of the gyromagnetic ratio in higher dimensions by considering the general solution for rotating charged black holes in minimal five-dimensional gauged supergravity. We obtain the analytic expressions for two distinct gyromagnetic ratios of these black holes that are associated with their two independent rotation parameters. These expressions reveal the dependence of the gyromagnetic ratio on both the curvature radius of the AdS background and the parameters of the black holes: The mass, electric charge, and two rotation parameters. We explore some special cases of interest and show that when the two rotation parameters are equal to each other and the rotation occurs at the maximum angular velocity, the gyromagnetic ratio g=4 regardless of the value of the electric charge. This agrees precisely with our earlier result obtained for general Kerr-AdS black holes with a test electric charge. We also show that in the Bogomol’nyi-Prasad-Sommerfield (BPS) limit the gyromagnetic ratio for a supersymmetric black hole with equal rotation parameters ranges between 2 and 4.

  2. Rotating spacetimes with asymptotic nonflat structure and the gyromagnetic ratio

    SciTech Connect

    Aliev, Alikram N.

    2008-02-15

    In general relativity, the gyromagnetic ratio for all stationary, axisymmetric, and asymptotically flat Einstein-Maxwell fields is known to be g=2. In this paper, we continue our previous works of examination of this result for rotating charged spacetimes with asymptotic nonflat structure. We first consider two instructive examples of these spacetimes: The spacetime of a Kerr-Newman black hole with a straight cosmic string on its axis of symmetry and the Kerr-Newman Taub-NUT (Newman-Unti-Tamburino) spacetime. We show that for both spacetimes the gyromagnetic ratio g=2 independent of their asymptotic structure. We also extend this result to a general class of metrics which admit separation of variables for the Hamilton-Jacobi and wave equations. We proceed with the study of the gyromagnetic ratio in higher dimensions by considering the general solution for rotating charged black holes in minimal five-dimensional gauged supergravity. We obtain the analytic expressions for two distinct gyromagnetic ratios of these black holes that are associated with their two independent rotation parameters. These expressions reveal the dependence of the gyromagnetic ratio on both the curvature radius of the AdS background and the parameters of the black holes: The mass, electric charge, and two rotation parameters. We explore some special cases of interest and show that when the two rotation parameters are equal to each other and the rotation occurs at the maximum angular velocity, the gyromagnetic ratio g=4 regardless of the value of the electric charge. This agrees precisely with our earlier result obtained for general Kerr-AdS black holes with a test electric charge. We also show that in the Bogomol'nyi-Prasad-Sommerfield (BPS) limit the gyromagnetic ratio for a supersymmetric black hole with equal rotation parameters ranges between 2 and 4.

  3. Gyromagnetically induced transparency of metasurfaces.

    PubMed

    Mousavi, S Hossein; Khanikaev, Alexander B; Allen, Jeffery; Allen, Monica; Shvets, Gennady

    2014-03-21

    We demonstrate that the presence of a (gyro) magnetic substrate can produce an analog of electromagnetically induced transparency in Fano-resonant metamolecules. The simplest implementation of such gyromagnetically induced transparency (GIT) in a metasurface, comprised of an array of resonant antenna pairs placed on a gyromagnetic substrate and illuminated by a normally incident electromagnetic wave, is analyzed. Time reversal and spatial inversion symmetry breaking introduced by the dc magnetization makes metamolecules bianisotropic. This causes Fano interference between the otherwise uncoupled symmetric and antisymmetric resonances of the metamolecules giving rise to a sharp transmission peak through the otherwise reflective metasurface. We show that, for an oblique wave incidence, one-way GIT can be achieved by the combination of spatial dispersion and gyromagnetic effect. These theoretically predicted phenomena pave the way to nonreciprocal switches and isolators that can be dynamically controlled by electric currents. PMID:24702414

  4. Gyromagnetically Induced Transparency of Metasurfaces

    NASA Astrophysics Data System (ADS)

    Mousavi, S. Hossein; Khanikaev, Alexander B.; Allen, Jeffery; Allen, Monica; Shvets, Gennady

    2014-03-01

    We demonstrate that the presence of a (gyro) magnetic substrate can produce an analog of electromagnetically induced transparency in Fano-resonant metamolecules. The simplest implementation of such gyromagnetically induced transparency (GIT) in a metasurface, comprised of an array of resonant antenna pairs placed on a gyromagnetic substrate and illuminated by a normally incident electromagnetic wave, is analyzed. Time reversal and spatial inversion symmetry breaking introduced by the dc magnetization makes metamolecules bianisotropic. This causes Fano interference between the otherwise uncoupled symmetric and antisymmetric resonances of the metamolecules giving rise to a sharp transmission peak through the otherwise reflective metasurface. We show that, for an oblique wave incidence, one-way GIT can be achieved by the combination of spatial dispersion and gyromagnetic effect. These theoretically predicted phenomena pave the way to nonreciprocal switches and isolators that can be dynamically controlled by electric currents.

  5. Gyromagnetically-induced transparency for ferrites

    NASA Astrophysics Data System (ADS)

    Chang, Tsun-Hsu

    2016-04-01

    The magnetic permeability is generally a second-rank tensor for an anisotropic medium. By considering a dc bias magnetic field and an ac circularly polarized wave, a generalized permeability can be derived. The formula for the generalized permeability explains why most dielectrics, paramagnetic and diamagnetic materials, and even metals have a relative permeability close to unity. For ferromagnetic or ferrimagnetic materials, the permeability strongly depends on the applied magnetic field and the polarizations of the electromagnetic waves. This work discusses how a circularly polarized wave interacts with the magnetic dipole moment being induced by and precessing around the applied dc bias field. The gyromagnetic resonance between the wave and the induced dipole allows us to find a condition where the incident wave can propagate through the medium without reflection. This explains the mysterious effect of gyromagnetically induced transparency.

  6. Gyromagnetically induced transparency of metasurfaces (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Shvets, Gennady B.; Mousavi, Hossein; Khanikaev, Alexander; Allen, Jeffery W.; Allen, Monica

    2015-09-01

    The concept of symmetry pervades modern physics. Through the conservation laws derived from various symmetries, high-level restrictions and selection rules can be derived for a variety of physical systems without any need for detailed investigations of their specific properties. The spatial symmetries of electric charge distribution on the metamaterial's surface determine whether the EM resonance is "bright" (radiatively coupled to) or "dark" (radiatively de-coupled from) the EM continuum. As we demonstrate in this talk, other (non-spatial) symmetries and their breaking can also be crucial to determine the properties of EM resonances and enable their mutual coupling, which in turn can give rise to EM Fano interferences. I will consider a meta-surface formed by a two-dimensional array of double-antenna meta-molecules resting on a gyromagnetic ferrite substrate. In conclusion, I will use simple symmetry considerations to predict and numerically demonstrate two phenomena that occur in meta-surfaces when symmetry of the system is reduced by a gyromagnetic substrate: gyromagnetically induced transparency and nonreciprocal Fano interference. These phenomena hold significant promise for practical applications such as the dynamic control of resonant EM interactions using magnetic fields produced by the external currents, mitigation of co-site interference and improving isolation. Spectral positions, radiative lifetimes and quality factors of Fano resonances can be controlled by the magnitude of the external magnetic field. This class of effects may lead to a new generation of tunable and nonreciprocal Fano resonant systems for various applications where strong field enhancement, tunability and nonreciprocity are simultaneously required.

  7. Nonreciprocal optical diffraction by a single layer of gyromagnetic cylinders.

    PubMed

    Guo, Tian-Jing; Li, Teng-Fei; Yang, Mu; Cui, Hai-Xu; Guo, Qing-Hua; Cao, Xue-Wei; Chen, Jing

    2014-01-13

    We study the diffraction of optical waves by a single layer of gyromagnetic cylinders. We show that a nonvanishing rotating dipole momentum is excited in a single gyromagnetic cylinder because of the classic analog of the Zeeman effect on photonic angular momentum states (PAMSs). Consequently, different collective dipole modes are excited in a gyromagnetic cylinder array at opposite incident angles. Nonreciprocal optical diffraction effects can be observed, where the transmission and reflection coefficients depend on the sign of the incident angle. A novel phenomenon of nonreciprocal negative directional transmission is demonstrated and numerically analyzed. This work highlights the potential of PAMSs in manipulating the propagation of optical waves for various applications. PMID:24515014

  8. Possibility of observing dark matter via the gyromagnetic Faraday effect.

    PubMed

    Gardner, Susan

    2008-02-01

    If dark matter consists of cold, neutral particles with a nonzero magnetic moment, then, in the presence of an external magnetic field, a measurable gyromagnetic Faraday effect becomes possible. This enables direct constraints on the nature and distribution of such dark matter through detailed measurements of the polarization and temperature of the cosmic-microwave background radiation. PMID:18352256

  9. Relativistic AC gyromagnetic effects in ultraintense laser-matter interaction.

    PubMed

    Geindre, J P; Audebert, P; Marjoribanks, R S

    2006-08-25

    We demonstrate that in ultraintense ultrafast laser-matter interaction, the interplay of laser-induced oscillating space-charge fields with laser E and B fields can strongly affect whether the interaction is relativistic or not: stronger laser fields may not in fact produce more relativistic plasma interactions. We show that there exists a regime of interaction, in the relation of laser intensity and incident angle, for which the Brunel effect of electron acceleration is strongly suppressed by AC gyromagnetic fields, at a frequency different from the laser field. Analytically and with 1.5D particle-in-cell modeling, we show that from gyromagnetic effects, even in the absence of usual J x B second-harmonic contributions, there are strong effects on the harmonic emission and on the generation of attosecond pulses. PMID:17026310

  10. Hyperfine-enhanced gyromagnetic ratio of a nuclear spin in diamond

    NASA Astrophysics Data System (ADS)

    Sangtawesin, S.; McLellan, C. A.; Myers, B. A.; Bleszynski Jayich, A. C.; Awschalom, D. D.; Petta, J. R.

    2016-08-01

    The nuclear spin gyromagnetic ratio can be enhanced by hyperfine coupling to the electronic spin. Here we show wide tunability of this enhancement on a 15N nuclear spin intrinsic to a single nitrogen-vacancy center in diamond. We perform control of the nuclear spin near the ground state level anti-crossing (GSLAC), where the enhancement of the gyromagnetic ratio from the ground state hyperfine coupling is maximized. We demonstrate a two order of magnitude enhancement of the effective nuclear gyromagnetic ratio compared to the value obtained at 500 G, a typical operating field that is suitable for nuclear spin polarization. Finally, we show that with strong enhancements, the nuclear spin ultimately suffers dephasing from the inhomogeneous broadening of the NMR transition frequency at the GSLAC.

  11. Simultaneous π/2 rotation of two spin species of different gyromagnetic ratios

    DOE PAGESBeta

    Chu, Ping -Han; Peng, Jen -Chieh

    2015-06-05

    Here, we examine the characteristics of the π/2 pulse for simultaneously rotating two spin species of different gyromagnetic ratios with the same sign. For a π/2 pulse using a rotating magnetic field, we derive an equation relating the frequency and strength of the pulse to the gyromagnetic ratios of the two particles and the strength of the constant holding field. For a π/2 pulse using a linear oscillatory magnetic field, we obtain the solutions numerically, and compare them with the solutions for the rotating π/2 pulse. Application of this analysis to the specific case of rotating neutrons and 3He atomsmore » simultaneously with a π/2 pulse, proposed for a neutron electric dipole moment experiment, is also presented.« less

  12. Spatial configuration of a plasma bunch formed under gyromagnetic resonance in a magnetic mirror trap

    NASA Astrophysics Data System (ADS)

    Andreev, V. V.; Novitskii, A. A.; Umnov, A. M.; Chuprov, D. V.

    2016-06-01

    The spatial configuration of a relativistic plasma bunch generated under the gyromagnetic autoresonance and confined in a magnetic mirror trap has been studied experimentally and numerically. The characteristics of bremsstrahlung generated by the plasma bunch from the gas and chamber walls were investigated using X-ray spectroscopy and radiometry, which made it possible to determine the localization of the bunch and analyze the dynamics of its confinement.

  13. Realization of self-guided unidirectional waveguides by a chain of gyromagnetic rods.

    PubMed

    Li, Zhen; Wu, Rui-Xin; Li, Qing-Bo; Poo, Yin

    2015-02-20

    To achieve a unidirectional transmission waveguide with miniature dimensions and flexible geometry, we propose a self-guided unidirectional waveguide composed of a chain of gyromagnetic rods. Two configurations of the waveguides were demonstrated. One is of a zigzag chain form, the other is a straight-line chain. These two types of waveguides have very wide one-way edge mode bandwidths. The simulated and experimental results illustrate their extraordinary wideband one-way transmission characteristics. They can also be expected to function as flexible platforms for practical applications because of their thin transverse dimensions and robustness to bending. PMID:25968186

  14. Large mode radius resonators

    NASA Technical Reports Server (NTRS)

    Harris, Michael R.

    1987-01-01

    Resonator configurations permitting operation with large mode radius while maintaining good transverse mode discrimination are considered. Stable resonators incorporating an intracavity telescope and unstable resonator geometries utilizing an output coupler with a Gaussian reflectivity profile are shown to enable large radius single mode laser operation. Results of heterodyne studies of pulsed CO2 lasers with large (11mm e sup-2 radius) fundamental mode sizes are presented demonstrating minimal frequency sweeping in accordance with the theory of laser-induced medium perturbations.

  15. Bias-field controlled phasing and power combination of gyromagnetic nonlinear transmission lines

    SciTech Connect

    Reale, D. V. Bragg, J.-W. B.; Gonsalves, N. R.; Johnson, J. M.; Neuber, A. A.; Dickens, J. C.; Mankowski, J. J.

    2014-05-15

    Gyromagnetic Nonlinear Transmission Lines (NLTLs) generate microwaves through the damped gyromagnetic precession of the magnetic moments in ferrimagnetic material, and are thus utilized as compact, solid-state, frequency agile, high power microwave (HPM) sources. The output frequency of a NLTL can be adjusted by control of the externally applied bias field and incident voltage pulse without physical alteration to the structure of the device. This property provides a frequency tuning capability not seen in many conventional e-beam based HPM sources. The NLTLs developed and tested are mesoband sources capable of generating MW power levels in the L, S, and C bands of the microwave spectrum. For an individual NLTL the output power at a given frequency is determined by several factors including the intrinsic properties of the ferrimagnetic material and the transmission line structure. Hence, if higher power levels are to be achieved, it is necessary to combine the outputs of multiple NLTLs. This can be accomplished in free space using antennas or in a transmission line via a power combiner. Using a bias-field controlled delay, a transient, high voltage, coaxial, three port, power combiner was designed and tested. Experimental results are compared with the results of a transient COMSOL simulation to evaluate combiner performance.

  16. Investigation of a stripline transmission line structure for gyromagnetic nonlinear transmission line high power microwave sources

    NASA Astrophysics Data System (ADS)

    Reale, D. V.; Parson, J. M.; Neuber, A. A.; Dickens, J. C.; Mankowski, J. J.

    2016-03-01

    A stripline gyromagnetic nonlinear transmission line (NLTL) was constructed out of yttrium iron garnet ferrite and tested at charge voltages of 35 kV-55 kV with bias fields ranging from 10 kA/m to 20 kA/m. Typically, high power gyromagnetic NLTLs are constructed in a coaxial geometry. While this approach has many advantages, including a uniform transverse electromagnetic (TEM) mode, simple interconnection between components, and the ability to use oil or pressurized gas as an insulator, the coaxial implementation suffers from complexity of construction, especially when using a solid insulator. By moving to a simpler transmission line geometry, NLTLs can be constructed more easily and arrayed on a single substrate. This work represents a first step in exploring the suitability of various transmission line structures, such as microstrips and coplanar waveguides. The resulting high power microwave (HPM) source operates in ultra high frequency (UHF) band with an average bandwidth of 40.1% and peak rf power from 2 MW to 12.7 MW.

  17. Repetitive sub-gigawatt rf source based on gyromagnetic nonlinear transmission line.

    PubMed

    Romanchenko, Ilya V; Rostov, Vladislav V; Gubanov, Vladimir P; Stepchenko, Alexey S; Gunin, Alexander V; Kurkan, Ivan K

    2012-07-01

    We demonstrate a high power repetitive rf source using gyromagnetic nonlinear transmission line to produce rf oscillations. Saturated NiZn ferrites act as active nonlinear medium first sharpening the pumping high voltage nanosecond pulse and then radiating at central frequency of about 1 GHz: shock rise time excites gyromagnetic precession in ferrites forming damping rf oscillations. The optimal length of nonlinear transmission line was found to be of about 1 m. SINUS-200 high voltage driver with Tesla transformer incorporated into pulse forming line has been designed and fabricated to produce bursts of 1000 pulses with 200 Hz repetition rate. A band-pass filter and mode-converter have been designed to extract rf pulse from low-frequency component and to form TE(11) mode of circular waveguide with linear polarization. A wide-band horn antenna has been fabricated to form Gaussian distribution of radiation pattern. The peak value of electric field strength of a radiated pulse at the distance of 3.5 m away from antenna is measured to be 160 kV/m. The corresponding rf peak power of 260 MW was achieved. PMID:22852710

  18. Bias-field controlled phasing and power combination of gyromagnetic nonlinear transmission lines.

    PubMed

    Reale, D V; Bragg, J-W B; Gonsalves, N R; Johnson, J M; Neuber, A A; Dickens, J C; Mankowski, J J

    2014-05-01

    Gyromagnetic Nonlinear Transmission Lines (NLTLs) generate microwaves through the damped gyromagnetic precession of the magnetic moments in ferrimagnetic material, and are thus utilized as compact, solid-state, frequency agile, high power microwave (HPM) sources. The output frequency of a NLTL can be adjusted by control of the externally applied bias field and incident voltage pulse without physical alteration to the structure of the device. This property provides a frequency tuning capability not seen in many conventional e-beam based HPM sources. The NLTLs developed and tested are mesoband sources capable of generating MW power levels in the L, S, and C bands of the microwave spectrum. For an individual NLTL the output power at a given frequency is determined by several factors including the intrinsic properties of the ferrimagnetic material and the transmission line structure. Hence, if higher power levels are to be achieved, it is necessary to combine the outputs of multiple NLTLs. This can be accomplished in free space using antennas or in a transmission line via a power combiner. Using a bias-field controlled delay, a transient, high voltage, coaxial, three port, power combiner was designed and tested. Experimental results are compared with the results of a transient COMSOL simulation to evaluate combiner performance. PMID:24880394

  19. On the Gyromagnetic and Gyrogravito-Magnetic Ratios of the Electron

    NASA Astrophysics Data System (ADS)

    Pollock, M. D.

    2015-06-01

    The magnetic dipole moment of the Kerr-Newman metric, defined by mass , electrical charge and angular momentum , is , corresponding, for all values of , to a gyromagnetic ratio , which is also the value of the intrinsic gyromagnetic ratio of the electron, as first noted by Carter. Here, we argue that this result can be understood in terms of the particle-wave complementarity principle. For can only be defined at asymptotic spatial infinity, where the metric appears to describe a spinning point particle, and therefore setting , , we necessarily have a model of the electron. From the Dirac equation we can construct a covariantly conserved four-current that is the source of the electromagnetic field generated by the charge . The result then follows from the minimal gauge principle which is implicit in the formulation of the spinorial wave equation, and which can also be justified from the line action for a spin-1/2 point particle interacting with an external electromagnetic field, due to Berezin and Marinov. By contrast, analysis of the gyrogravito-magnetic effect, investigated classically by Wald and quantum mechanically by Adler et al., yields the result in all non-relativistic cases, which can be explained from the principle of equivalence. The results are in accord with the correspondence principle.

  20. Bias-field controlled phasing and power combination of gyromagnetic nonlinear transmission lines

    NASA Astrophysics Data System (ADS)

    Reale, D. V.; Bragg, J.-W. B.; Gonsalves, N. R.; Johnson, J. M.; Neuber, A. A.; Dickens, J. C.; Mankowski, J. J.

    2014-05-01

    Gyromagnetic Nonlinear Transmission Lines (NLTLs) generate microwaves through the damped gyromagnetic precession of the magnetic moments in ferrimagnetic material, and are thus utilized as compact, solid-state, frequency agile, high power microwave (HPM) sources. The output frequency of a NLTL can be adjusted by control of the externally applied bias field and incident voltage pulse without physical alteration to the structure of the device. This property provides a frequency tuning capability not seen in many conventional e-beam based HPM sources. The NLTLs developed and tested are mesoband sources capable of generating MW power levels in the L, S, and C bands of the microwave spectrum. For an individual NLTL the output power at a given frequency is determined by several factors including the intrinsic properties of the ferrimagnetic material and the transmission line structure. Hence, if higher power levels are to be achieved, it is necessary to combine the outputs of multiple NLTLs. This can be accomplished in free space using antennas or in a transmission line via a power combiner. Using a bias-field controlled delay, a transient, high voltage, coaxial, three port, power combiner was designed and tested. Experimental results are compared with the results of a transient COMSOL simulation to evaluate combiner performance.

  1. Investigation of a stripline transmission line structure for gyromagnetic nonlinear transmission line high power microwave sources.

    PubMed

    Reale, D V; Parson, J M; Neuber, A A; Dickens, J C; Mankowski, J J

    2016-03-01

    A stripline gyromagnetic nonlinear transmission line (NLTL) was constructed out of yttrium iron garnet ferrite and tested at charge voltages of 35 kV-55 kV with bias fields ranging from 10 kA/m to 20 kA/m. Typically, high power gyromagnetic NLTLs are constructed in a coaxial geometry. While this approach has many advantages, including a uniform transverse electromagnetic (TEM) mode, simple interconnection between components, and the ability to use oil or pressurized gas as an insulator, the coaxial implementation suffers from complexity of construction, especially when using a solid insulator. By moving to a simpler transmission line geometry, NLTLs can be constructed more easily and arrayed on a single substrate. This work represents a first step in exploring the suitability of various transmission line structures, such as microstrips and coplanar waveguides. The resulting high power microwave (HPM) source operates in ultra high frequency (UHF) band with an average bandwidth of 40.1% and peak rf power from 2 MW to 12.7 MW. PMID:27036802

  2. The Proton Radius Puzzle

    NASA Astrophysics Data System (ADS)

    Downie, E. J.

    2016-03-01

    The proton radius puzzle is the difference between the proton radius as measured with electron scattering and in the excitation spectrum of atomic hydrogen, and that measured with muonic hydrogen spectroscopy. Since the inception of the proton radius puzzle in 2010 by the measurement of Pohl et al.[1], many possible resolutions to the puzzle have been postulated, but, to date, none has been generally accepted. New data are therefore necessary to resolve the issue. We briefly review the puzzle, the proposed solutions, and the new electron scattering and spectroscopy experiments planned and underway. We then introduce the MUSE experiment, which seeks to resolve the puzzle by simultaneously measuring elastic electron and muon scattering on the proton, in both charge states, thereby providing new information to the puzzle. MUSE addresses issues of two-photon effects, lepton universality and, possibly, new physics, while providing simultaneous form factor, and therefore radius, measurements with both muons and electrons.

  3. Characteristics of a four element gyromagnetic nonlinear transmission line array high power microwave source.

    PubMed

    Johnson, J M; Reale, D V; Krile, J T; Garcia, R S; Cravey, W H; Neuber, A A; Dickens, J C; Mankowski, J J

    2016-05-01

    In this paper, a solid-state four element array gyromagnetic nonlinear transmission line high power microwave system is presented as well as a detailed description of its subsystems and general output capabilities. This frequency agile S-band source is easily adjusted from 2-4 GHz by way of a DC driven biasing magnetic field and is capable of generating electric fields of 7.8 kV/m at 10 m correlating to 4.2 MW of RF power with pulse repetition frequencies up to 1 kHz. Beam steering of the array at angles of ±16.7° is also demonstrated, and the associated general radiation pattern is detailed. PMID:27250448

  4. Characteristics of a four element gyromagnetic nonlinear transmission line array high power microwave source

    NASA Astrophysics Data System (ADS)

    Johnson, J. M.; Reale, D. V.; Krile, J. T.; Garcia, R. S.; Cravey, W. H.; Neuber, A. A.; Dickens, J. C.; Mankowski, J. J.

    2016-05-01

    In this paper, a solid-state four element array gyromagnetic nonlinear transmission line high power microwave system is presented as well as a detailed description of its subsystems and general output capabilities. This frequency agile S-band source is easily adjusted from 2-4 GHz by way of a DC driven biasing magnetic field and is capable of generating electric fields of 7.8 kV/m at 10 m correlating to 4.2 MW of RF power with pulse repetition frequencies up to 1 kHz. Beam steering of the array at angles of ±16.7° is also demonstrated, and the associated general radiation pattern is detailed.

  5. High power microwave beam steering based on gyromagnetic nonlinear transmission lines

    NASA Astrophysics Data System (ADS)

    Romanchenko, I. V.; Rostov, V. V.; Gunin, A. V.; Konev, V. Yu.

    2015-06-01

    We demonstrate electronically controlled beam steering by high power RF pulses produced by two gyromagnetic nonlinear transmission lines (NLTLs) connected to a one high voltage driver. Each NLTL is capable of producing several ns RF pulses with peak power from 50 to 700 MW (6% standard deviation) at frequencies from 0.5 to 1.7 GHz (1% standard deviation) with 100 Hz repetition rate. Using a helix antenna allows irradiating of RF pulses with almost circular polarization and 350 MW maximum peak power, which corresponds to 350 kV effective potential of radiation. At the installation of two identical channels, we demonstrate the possibility of beam steering within ±15° in the horizontal plane by coherent RF pulses with circular polarization at 1.0 GHz center frequency. Fourfold increase in the power flux density for in-phase irradiation of RF pulses is confirmed by comparison with one-channel operation.

  6. High power microwave beam steering based on gyromagnetic nonlinear transmission lines

    SciTech Connect

    Romanchenko, I. V. Rostov, V. V.; Gunin, A. V.; Konev, V. Yu.

    2015-06-07

    We demonstrate electronically controlled beam steering by high power RF pulses produced by two gyromagnetic nonlinear transmission lines (NLTLs) connected to a one high voltage driver. Each NLTL is capable of producing several ns RF pulses with peak power from 50 to 700 MW (6% standard deviation) at frequencies from 0.5 to 1.7 GHz (1% standard deviation) with 100 Hz repetition rate. Using a helix antenna allows irradiating of RF pulses with almost circular polarization and 350 MW maximum peak power, which corresponds to 350 kV effective potential of radiation. At the installation of two identical channels, we demonstrate the possibility of beam steering within ±15° in the horizontal plane by coherent RF pulses with circular polarization at 1.0 GHz center frequency. Fourfold increase in the power flux density for in-phase irradiation of RF pulses is confirmed by comparison with one-channel operation.

  7. Observation of broadband unidirectional transmission by fusing the one-way edge states of gyromagnetic photonic crystals.

    PubMed

    Li, Zhen; Wu, Rui-xin; Li, Qing-Bo; Lin, Zhi-fang; Poo, Yin; Liu, Rong-Juan; Li, Zhi-Yuan

    2015-04-20

    We experimentally demonstrate a broadband one-way transmission by merging the operating bands of two types of one-way edge modes that are associated with Bragg scattering and magnetic surface plasmon (MSP) resonance, respectively. By tuning the configuration of gyromagnetic photonic crystals and applied bias magnetic field, the fused bandwidth of unidirectional propagation is up to 2 GHz in microwave frequency range, much larger than either of the individual one-way bandwidth associated with Bragg scattering or MSP resonance. Our scheme for broadband one-way transmission paves the way for the practical applications of one-way transmission. PMID:25969002

  8. Distal radius fractures: current concepts.

    PubMed

    Schneppendahl, Johannes; Windolf, Joachim; Kaufmann, Robert A

    2012-08-01

    Despite the frequency of distal radius fractures, the optimal treatment remains without consensus opinion. A trend toward increased distal radius fracture open reduction and internal fixation has been identified, with biomechanical and clinical studies suggesting treatment advantages of certain fixation methods over others. Well-controlled patient trials are still missing to lend objective findings to management algorithms. This article reviews the literature over the past 5 years to guide our management regarding this common upper-extremity injury. PMID:22763062

  9. Laser differential confocal radius measurement.

    PubMed

    Zhao, Weiqian; Sun, Ruoduan; Qiu, Lirong; Sha, Dingguo

    2010-02-01

    A new laser differential confocal radius measurement (DCRM) is proposed for high precision measurement of radius. Based on the property of an axial intensity curve that the absolute zero precisely corresponds to the focus of the objective in a differential confocal system (DCS), DCRM uses the zero point of the DCS axial intensity curve to precisely identify the cat's-eye and confocal positions of the test lens, and measures the accurate distance between the two positions to achieve the high-precision measurement of radius of curvature (ROC). In comparison with the existing measurement methods, DCRM proposed has a high measurement precision, a strong environmental anti-interference capability and a low cost. The theoretical analyses and preliminary experimental results indicate that DCRM has a relative measurement error of better than 5 ppm. PMID:20174065

  10. Zeeman splitting, its specific features, and gyromagnetic ratios for configurations 1 snf ( n = 4-10) of the helium atom

    NASA Astrophysics Data System (ADS)

    Anisimova, G. P.; Gorbenko, A. P.; Dolmatova, O. A.; Krylov, I. R.; Mashek, I. Ch.; Tsygankova, G. A.

    2016-02-01

    The fine structure parameters of configurations 1 snf ( n = 4-10) with new refined energy values are calculated by the semiempirical method. The emphasis is on the study of the Zeeman structure in order to determine the gyromagnetic ratios of all four the levels of the configuration from the splitting. For this purpose, the matrices of an energy operator with allowance for the interaction between the atom and a magnetic field were diagonalized for all possible values of quantum number M. For each configuration, 17 values of crossing fields of the Zeeman sublevels with Δ M = ±1, ±2 and the regions of anticrossings with Δ M = 0 were determined. It is remarkable that, because the levels are closely spaced, anticrossings are observed for each pair of levels in these systems. The regions of linearity of a magnetic field, which are different for different configurations, and the levels in them are established. The g-factors are calculated from the coefficients of an intermediate coupling scheme in a magnetic field that is guaranteed to be linear. They are compared with the analogous values in the absence of a field.

  11. Radius of curvature controlled mirror

    DOEpatents

    Neil, George R.; Rathke, John Wickham; Schultheiss, Thomas John; Shinn, Michelle D.; Dillon-Townes, Lawrence A.

    2006-01-17

    A controlled radius of curvature mirror assembly comprising: a distortable mirror having a reflective surface and a rear surface; and in descending order from the rear surface; a counter-distortion plate; a flow diverter having a flow diverter aperture at the center thereof; a flow return plate having a flow return aperture at the center thereof; a thermal isolation plate having a thermal isolation plate aperture at the center thereof and a flexible heater having a rear surface and a flexible heater aperture at the center thereof; a double walled tube defining a coolant feed chamber and a coolant return chamber; said coolant feed chamber extending to and through the flow diverter aperture and terminating at the counter-distortion plate and the coolant return chamber extending to and through the thermal isolation backplate and terminating at the flow diverter; and a coolant feed and a coolant return exit at the rear of said flexible heater.

  12. Treatment of distal radius fractures.

    PubMed

    Lichtman, David M; Bindra, Randipsingh R; Boyer, Martin I; Putnam, Matthew D; Ring, David; Slutsky, David J; Taras, John S; Watters, William C; Goldberg, Michael J; Keith, Michael; Turkelson, Charles M; Wies, Janet L; Haralson, Robert H; Boyer, Kevin M; Hitchcock, Kristin; Raymond, Laura

    2010-03-01

    The clinical practice guideline is based on a systematic review of published studies on the treatment of distal radius fractures in adults. None of the 29 recommendations made by the work group was graded as strong; most are graded as inconclusive or consensus; seven are graded as weak. The remaining five moderate-strength recommendations include surgical fixation, rather than cast fixation, for fractures with postreduction radial shortening >3 mm, dorsal tilt >10 degrees , or intra-articular displacement or step-off >2 mm; use of rigid immobilization rather than removable splints for nonsurgical treatment; making a postreduction true lateral radiograph of the carpus to assess dorsal radial ulnar joint alignment; beginning early wrist motion following stable fixation; and recommending adjuvant treatment with vitamin C to prevent disproportionate pain. PMID:20190108

  13. Treatment of distal radius fractures.

    PubMed

    Murray, Jayson; Gross, Leeaht

    2013-08-01

    The American Academy of Orthopaedic Surgeons has developed Appropriate Use Criteria (AUC) for treating distal radius fractures (DRF). Evidence-based information, in conjunction with the clinical expertise of physicians, was used to develop the criteria to improve patient care and obtain best outcomes while considering the subtleties and distinctions necessary in making clinical decisions. The DRF AUC clinical patient scenarios were derived from patient indications that generally accompany a DRF, as well as from current evidence-based clinical practice guidelines and supporting literature. The 216 indications and 10 treatments were developed by the Writing Panel, a group of clinicians who are specialists in this AUC topic. Next, the Review Panel, a separate group of volunteer physicians, independently reviewed these materials to ensure that they were representative of patient scenarios that clinicians are likely to encounter in daily practice. Finally, the multidisciplinary Voting Panel (made up of specialists and nonspecialists) rated the appropriateness of treatment of each patient scenario using a 9-point scale to designate a treatment as Appropriate (median rating, 7 to 9), May Be Appropriate (median rating, 4 to 6), or Rarely Appropriate (median rating, 1 to 3). PMID:23908256

  14. Mirror with thermally controlled radius of curvature

    DOEpatents

    Neil, George R.; Shinn, Michelle D.

    2010-06-22

    A radius of curvature controlled mirror for controlling precisely the focal point of a laser beam or other light beam. The radius of curvature controlled mirror provides nearly spherical distortion of the mirror in response to differential expansion between the front and rear surfaces of the mirror. The radius of curvature controlled mirror compensates for changes in other optical components due to heating or other physical changes. The radius of curvature controlled mirror includes an arrangement for adjusting the temperature of the front surface and separately adjusting the temperature of the rear surface to control the radius of curvature. The temperature adjustment arrangements can include cooling channels within the mirror body or convection of a gas upon the surface of the mirror. A control system controls the differential expansion between the front and rear surfaces to achieve the desired radius of curvature.

  15. Chondromyxoid Fibroma of Radius: A Case Report

    PubMed Central

    Bagewadi, Rajakumar M.; Hippargi, Surekha B.

    2016-01-01

    Chondromyxoid fibroma (CMF) is a rare benign cartilaginous tumour accounting to less than 1% of bone tumours. It is most commonly seen in lower extremity involving tibia. CMF of radius is rare. We report a rare case of CMF of proximal radius in a 37-year-old female who presented with swelling and pain over right elbow. Wide local excision of proximal radius along with radial head was done and above elbow POP slab was applied for one month. Elbow range of movement exercises started after one month. PMID:27437232

  16. Management of Complications of Distal Radius Fractures

    PubMed Central

    Chung, Kevin C.; Mathews, Alexandra L.

    2015-01-01

    Synopsis Treating a fracture of the distal radius may require the surgeon to make a difficult decision between surgical treatment and nonsurgical management. The use of surgical fixation has recently increased owing to complications associated with conservative treatment. However, conservative action may be necessary depending on certain patient factors. The treating surgeon must be aware of the possible complications associated with distal radius fracture treatments to prevent their occurrence. Prevention can be achieved with a proper understanding of the mechanism of these complications. This article discusses the most recent evidence on how to manage and prevent complications following a fracture of the distal radius. PMID:25934197

  17. Chondromyxoid Fibroma of Radius: A Case Report.

    PubMed

    Bagewadi, Rajakumar M; Nerune, Savitri Mallikarjun; Hippargi, Surekha B

    2016-05-01

    Chondromyxoid fibroma (CMF) is a rare benign cartilaginous tumour accounting to less than 1% of bone tumours. It is most commonly seen in lower extremity involving tibia. CMF of radius is rare. We report a rare case of CMF of proximal radius in a 37-year-old female who presented with swelling and pain over right elbow. Wide local excision of proximal radius along with radial head was done and above elbow POP slab was applied for one month. Elbow range of movement exercises started after one month. PMID:27437232

  18. Large-Larmor-radius interchange instability

    SciTech Connect

    Ripin, B.H.; McLean, E.A.; Manka, C.K.; Pawley, C.; Stamper, J.A.; Peyser, T.A.; Mostovych, A.N.; Grun, J.; Hassam, A.B.; Huba, J.

    1987-11-16

    We observe linear and nonlinear features of a strong plasma/magnetic field interchange Rayleigh-Taylor instability in the limit of large ion Larmor radius. The instability undergoes rapid linear growth culminating in free-streaming flute tips.

  19. Arthroscopic management of distal radius fractures.

    PubMed

    Wiesler, Ethan R; Chloros, George D; Mahirogullari, Mahir; Kuzma, Gary R

    2006-11-01

    Arthroscopy has the advantage of providing a direct and accurate assessment of the articular surfaces and detecting the presence of injuries associated with distal radius fractures. Current indications, although numerous and potentially expanding, also are controversial. This report presents a global view of the current status of arthroscopy in the management of distal radius fractures. The rationale of arthroscopic treatment, the available evidence, and finally the diagnosis and treatment are discussed. PMID:17095385

  20. A Maximum Radius for Habitable Planets.

    PubMed

    Alibert, Yann

    2015-09-01

    We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope. PMID:26159097

  1. Mass and radius of cosmic balloons

    NASA Technical Reports Server (NTRS)

    Wang, Yun

    1994-01-01

    Cosmic balloons are spherical domain walls with relativistic particles trapped inside. We derive the exact mass and radius relations for a static cosmic balloon using Gauss-Codazzi equations. The cosmic balloon mass as a function of its radius, M(R), is found to have a functional form similar to that of fermion soliton stars, with a fixed point at 2GM(R)/R approximately or equal to 0.486 which corresponds to the limit of infinite central density. We derive a simple analytical approximation for the mass density of a spherically symmetric relativistic gas star. When applied to the computation of the mass and radius of a cosmic balloon, the analytical approximation yields fairly good agreement with the exact numerical solutions.

  2. Inside the Bondi radius of M87

    NASA Astrophysics Data System (ADS)

    Russell, H. R.; Fabian, A. C.; McNamara, B. R.; Broderick, A. E.

    2015-07-01

    Chandra X-ray observations of the nearby brightest cluster galaxy M87 resolve the hot gas structure across the Bondi accretion radius of the central supermassive black hole (SMBH), a measurement possible in only a handful of systems but complicated by the bright nucleus and jet emission. By stacking only short frame-time observations to limit pileup, and after subtracting the nuclear point spread function, we analysed the X-ray gas properties within the Bondi radius at 0.12-0.22 kpc (1.5-2.8 arcsec), depending on the black hole mass. Within 2 kpc radius, we detect two significant temperature components, which are consistent with constant values of 2 and 0.9 keV down to 0.15 kpc radius. No evidence was found for the expected temperature increase within ˜ 0.25 kpc due to the influence of the SMBH. Within the Bondi radius, the density profile is consistent with ρ ∝ r-1. The lack of a temperature increase inside the Bondi radius suggests that the hot gas structure is not dictated by the SMBH's potential and, together with the shallow density profile, shows that the classical Bondi rate may not reflect the accretion rate on to the SMBH. If this density profile extends in towards the SMBH, the mass accretion rate on to the SMBH could be at least two orders of magnitude less than the Bondi rate, which agrees with Faraday rotation measurements for M87. We discuss the evidence for outflow from the hot gas and the cold gas disc and for cold feedback, where gas cooling rapidly from the hot atmosphere could feed the cirumnuclear disc and fuel the SMBH. At 0.2 kpc radius, the cooler X-ray temperature component represents ˜20 per cent of the total X-ray gas mass and, by losing angular momentum to the hot gas component, could provide a fuel source of cold clouds within the Bondi radius.

  3. Distal radius fracture: diagnosis, treatment, and controversies.

    PubMed

    Tang, Jin Bo

    2014-07-01

    This article presents the diagnosis and treatment of distal radius fractures with emphasis on (1) current common principles, (2) the author's current practices, and (3) controversies. The author emphasizes that displaced distal radius fractures should be approached first with a trial of closed reduction, with or without percutaneous pinning. If this reduction is unstable or unsuccessful, open reduction is indicated. Early treatments include percutaneous pinning through the distal radioulnar joint, early or delayed reattachment/repair of the avulsed dorsal periphery of the triangular fibrocartilage complex (TFCC), reattachment of the TFCC to the ulna fovea, and late reconstruction. PMID:24996466

  4. Exposure of the forearm and distal radius.

    PubMed

    Klausmeyer, Melissa A; Mudgal, Chaitanya

    2014-11-01

    Approaches to the forearm use internervous planes to allow adequate bone exposure and prevent muscle denervation. The Henry approach utilizes the plane between muscles supplied by the median and radial nerves. The Thompson approach utilizes the plane between muscles supplied by the radial and posterior interosseous nerves. The distal radius may be approached volarly. The extended flexor carpi radialis approach is useful for intraarticular fractures, subacute fractures, and malunions. The distal radius can be approached dorsally by releasing the third dorsal compartment and continuing the dissection subperiosteally. Choice of approach depends on the injury pattern and the need for exposure. PMID:25440071

  5. The Tidal Radius of the Arches Cluster

    NASA Astrophysics Data System (ADS)

    Hosek, Matthew; Lu, Jessica R.; Anderson, Jay; Ghez, Andrea; Morris, Mark; Clarkson, William

    2015-08-01

    At a projected distance of just ˜26 pc from the center of the Milky Way, the Arches cluster allows us to examine the structure of a young massive cluster in the strong tidal environment of the Galactic center (GC). We use the HST WFC3IR camera to conduct an astrometric and photometric study of the outer region of the Arches cluster (R > 6.25”) in order to measure its radial profile. Using proper motions we separate cluster members from field stars down to F153M = 20 mag (˜2.5 M_sun) over a 120” x 120” field of view, covering an area 144 times larger than previous proper motion studies. This is a significant improvement over photometrically-determined cluster membership, which is complicated by the high degree of differential reddening across the field. Using cluster membership probabilities, a derived extinction map, and extensive completeness simulations, we construct the radial profile of the Arches cluster to a radius of ˜80” (˜3.1 pc assuming a distance of 8 kpc). Evidence of mass segregation out to this radius is observed, and no significant tidal tail structure is apparent. We find that the projected radial extent of the Arches cluster is significantly larger than its expected tidal radius. This result suggests either that the cluster is not as close to the GC as previously thought or that it is inflated beyond its nominal tidal radius.

  6. Proton radius from electron scattering data

    NASA Astrophysics Data System (ADS)

    Higinbotham, Douglas W.; Kabir, Al Amin; Lin, Vincent; Meekins, David; Norum, Blaine; Sawatzky, Brad

    2016-05-01

    Background: The proton charge radius extracted from recent muonic hydrogen Lamb shift measurements is significantly smaller than that extracted from atomic hydrogen and electron scattering measurements. The discrepancy has become known as the proton radius puzzle. Purpose: In an attempt to understand the discrepancy, we review high-precision electron scattering results from Mainz, Jefferson Lab, Saskatoon, and Stanford. Methods: We make use of stepwise regression techniques using the F test as well as the Akaike information criterion to systematically determine the predictive variables to use for a given set and range of electron scattering data as well as to provide multivariate error estimates. Results: Starting with the precision, low four-momentum transfer (Q2) data from Mainz (1980) and Saskatoon (1974), we find that a stepwise regression of the Maclaurin series using the F test as well as the Akaike information criterion justify using a linear extrapolation which yields a value for the proton radius that is consistent with the result obtained from muonic hydrogen measurements. Applying the same Maclaurin series and statistical criteria to the 2014 Rosenbluth results on GE from Mainz, we again find that the stepwise regression tends to favor a radius consistent with the muonic hydrogen radius but produces results that are extremely sensitive to the range of data included in the fit. Making use of the high-Q2 data on GE to select functions which extrapolate to high Q2, we find that a Padé (N =M =1 ) statistical model works remarkably well, as does a dipole function with a 0.84 fm radius, GE(Q2) =(1+Q2/0.66 GeV2) -2 . Conclusions: Rigorous applications of stepwise regression techniques and multivariate error estimates result in the extraction of a proton charge radius that is consistent with the muonic hydrogen result of 0.84 fm; either from linear extrapolation of the extremely-low-Q2 data or by use of the Padé approximant for extrapolation using a larger

  7. On solar radius measurements with PICARD

    NASA Astrophysics Data System (ADS)

    Meftah, M.; Irbah, A.; Hauchecorne, A.; Corbard, T.; Hochedez, J. F.

    2014-12-01

    Solar diameter measurements performed from the ground for several decades seem to indicate a relation between the solar diameter and the solar activity. If this relationship is confirmed, it would be possible to use measurements of solar diameter as a proxy of solar activity in the past since the 1715 solar eclipses, and to use this input for the reconstruction of solar irradiance in climate models. However the interpretation of ground observations is controversial, ground-based measurements being affected by refraction, by atmospheric turbulence, and perhaps by atmospheric aerosols scattering. The only way to be free from atmospheric effects is to measure from space. This is the reason why, since the beginning, the PICARD program included a space and a ground component set up at the Calern site of the Observatoire de la Côte dAzur. During the last 4 years, the PICARD space mission has been used for observing the apparent solar diameter. First results of the astrometry program include a study of the June 2012 Venus transit for solar diameter determination. From this, the value of the solar radius from one astronomical unit was found to be equal to 959.86 arc-seconds at 607.1 nm. However, concerning observed variations in time of the solar radius, instrumental effects affect the results. Space is known to represent a harsh environment for optical instruments. Nevertheless, we can use the PICARD data to monitor the solar radius variation. PICARD aims to perpetuate historical series of the solar radius measurements, in particular during the solar cycle 24. This paper presents solar radius measurements obtained with PICARD.

  8. MASS-RADIUS RELATIONSHIPS FOR EXOPLANETS

    SciTech Connect

    Swift, D. C.; Eggert, J. H.; Hicks, D. G.; Hamel, S.; Caspersen, K.; Schwegler, E.; Collins, G. W.; Nettelmann, N.; Ackland, G. J.

    2012-01-01

    For planets other than Earth, particularly exoplanets, interpretation of the composition and structure depends largely on comparing the mass and radius with the composition expected given their distance from the parent star. The composition implies a mass-radius relation which relies heavily on equations of state calculated from electronic structure theory and measured experimentally on Earth. We lay out a method for deriving and testing equations of state, and deduce mass-radius and mass-pressure relations for key, relevant materials whose equation of state (EOS) is reasonably well established, and for differentiated Fe/rock. We find that variations in the EOS, such as may arise when extrapolating from low-pressure data, can have significant effects on predicted mass-radius relations and on planetary pressure profiles. The relations are compared with the observed masses and radii of planets and exoplanets, broadly supporting recent inferences about exoplanet structures. Kepler-10b is apparently 'Earth-like', likely with a proportionately larger core than Earth's, nominally 2/3 of the mass of the planet. CoRoT-7b is consistent with a rocky mantle over an Fe-based core which is likely to be proportionately smaller than Earth's. GJ 1214b lies between the mass-radius curves for H{sub 2}O and CH{sub 4}, suggesting an 'icy' composition with a relatively large core or a relatively large proportion of H{sub 2}O. CoRoT-2b is less dense than the hydrogen relation, which could be explained by an anomalously high degree of heating or by higher than assumed atmospheric opacity. HAT-P-2b is slightly denser than the mass-radius relation for hydrogen, suggesting the presence of a significant amount of matter of higher atomic number. CoRoT-3b lies close to the hydrogen relation. The pressure at the center of Kepler-10b is 1.5{sup +1.2}{sub -1.0} TPa. The central pressure in CoRoT-7b is probably close to 0.8 TPa, though may be up to 2 TPa. These pressures are accessible by planar

  9. Running with the radius in RS1

    NASA Astrophysics Data System (ADS)

    Lewandowski, Adam; May, Michael J.; Sundrum, Raman

    2003-01-01

    We derive a renormalization group formalism for the Randall-Sundrum scenario, where the renormalization scale is set by a floating compactification radius. While inspired by the AdS-CFT conjecture, our results are derived concretely within higher-dimensional effective field theory. Matching theories with different radii leads to running hidden brane couplings. The hidden brane Lagrangian consists of four-dimensional local operators constructed from the induced value of the bulk fields on the brane. We find hidden Lagrangians which are nontrivial fixed points of the RG flow. Calculations in RS1 can be greatly simplified by “running down” the effective theory to a small radius. We demonstrate these simplifications by studying the Goldberger-Wise stabilization mechanism. In this paper, we focus on the classical and tree-level quantum field theory of bulk scalar fields, which demonstrates the essential features of the RG in the simplest context.

  10. Surgical exposures of the radius and ulna.

    PubMed

    Catalano, Louis W; Zlotolow, Dan A; Hitchcock, Phillip B; Shah, Suparna N; Barron, O Alton

    2011-07-01

    The forearm contains many muscles, nerves, and vascular structures that change position on forearm rotation. Exposure of the radial shaft is best achieved with the Henry (volar) or Thompson (dorsal) approach. The volar flexor carpi radialis approaches are used increasingly for exposure of the distal radius. Although the dorsal approach is a safe utilitarian option with many applications, its use for managing fracture of the distal radius has waned. Potential complications associated with radial exposure include injury to the superficial branch of the radial nerve, the lateral antebrachial cutaneous nerve, and the cephalic vein. Dorsal and ulnar proximal radial exposures are associated with increased risk of injury to the posterior interosseous nerve. With surgical exposure of the ulna, care is required to avoid injuring the dorsal cutaneous branch of the ulnar nerve. PMID:21724922

  11. The Epidemiology of Distal Radius Fractures

    PubMed Central

    Nellans, Kate W.; Kowalski, Evan; Chung, Kevin C.

    2012-01-01

    Distal radius fractures are one of the most common types of fractures, accounting for around 25% of fractures in the pediatric population and up to 18% of all fractures in the elderly age group. Although the pediatric and elderly populations are at the greatest risk for this injury, distal radius fractures still have a significant impact on the health and well-being of young adults. Data from the past 40 years has documented a trend towards an overall increase in the prevalence of this injury. For the pediatric population, this increase can likely be attributed to a surge in sports related activities. The growth of the elderly population and a rise in the number of active elderly are directly responsible for the increase seen in this age group. Understanding the epidemiology of this fracture is an important step towards the improvement of the treatment strategies and preventative measures which target this debilitating injury. PMID:22554654

  12. Fractures of distal radius: an overview.

    PubMed

    Meena, Sanjay; Sharma, Pankaj; Sambharia, Abhishek Kumar; Dawar, Ashok

    2014-01-01

    Fractures of distal radius account for up to 20% of all fractures treated in emergency department. Initial assessment includes a history of mechanism of injury, associated injury and appropriate radiological evaluation. Treatment options include conservative management, internal fixation with pins, bridging and non-bridging external fixation, dorsal or volar plating with/without arthroscopy assistance. However, many questions regarding these fractures remain unanswered and good prospective randomized trials are needed. PMID:25657938

  13. Fractures of Distal Radius: An Overview

    PubMed Central

    Meena, Sanjay; Sharma, Pankaj; Sambharia, Abhishek Kumar; Dawar, Ashok

    2014-01-01

    Fractures of distal radius account for up to 20% of all fractures treated in emergency department. Initial assessment includes a history of mechanism of injury, associated injury and appropriate radiological evaluation. Treatment options include conservative management, internal fixation with pins, bridging and non-bridging external fixation, dorsal or volar plating with/without arthroscopy assistance. However, many questions regarding these fractures remain unanswered and good prospective randomized trials are needed. PMID:25657938

  14. Ulnar Shortening Osteotomy for Distal Radius Malunion

    PubMed Central

    Kamal, Robin N.; Leversedge, Fraser J.

    2014-01-01

    Background Malunion is a common complication of distal radius fractures. Ulnar shortening osteotomy (USO) may be an effective treatment for distal radius malunion when appropriate indications are observed. Methods The use of USO for treatment of distal radius fracture malunion is described for older patients (typically patients >50 years) with dorsal or volar tilt less than 20 degrees and no carpal malalignment or intercarpal or distal radioulnar joint (DRUJ) arthritis. Description of Technique Preoperative radiographs are examined to ensure there are no contraindications to ulnar shortening osteotomy. The neutral posteroanterior (PA) radiograph is used to measure ulnar variance and to estimate the amount of ulnar shortening required. An ulnar, mid-sagittal incision is used and the dorsal sensory branch of the ulnar nerve is preserved. An USO-specific plating system with cutting jig is used to create parallel oblique osteotomies to facilitate shortening. Intraoperative fluoroscopy and clinical range of motion are checked to ensure adequate shortening and congruous reduction of the ulnar head within the sigmoid notch. Results Previous outcomes evaluation of USO has demonstrated improvement in functional activities, including average flexion-extension and pronosupination motions, and patient reported outcomes. Conclusion The concept and technique of USO are reviewed for the treatment of distal radius malunion when specific indications are observed. Careful attention to detail related to surgical indications and to surgical technique typically will improve range of motion, pain scores, and patient-reported outcomes and will reduce the inherent risks of the procedure, such as ulnar nonunion or the symptoms related to unrecognized joint arthritis. Level of Evidence: Level IV PMID:25097811

  15. Solar Radius Measurements at Mount Wilson

    NASA Astrophysics Data System (ADS)

    Lefebvre, S.; Bertello, L.; Ulrich, R. K.; Boyden, J. E.; Rozelot, J.

    2004-12-01

    Variations of the solar radius are not only important for solar physics but they also play a fundamental role in the research of terrestrial climate. In fact, changes in the apparent size of the Sun could account for a significant fraction of the total irradiance variations, and solar irradiance is known to be a primary force in driving atmospheric circulation. While the MDI instrument aboard SOHO is likely to provide the most accurate constraint on possible solar radius variations, the radius measurements obtained from ground base observations represent a unique resource due to their long temporal coverage. Since 1970, the Mount Wilson synoptic programme of solar magnetic observations carried out at the 150-foot tower scans the solar disk using the radiation in the neutral iron line at 525.0 nm. For these images, the radius has been determined and results are presented on this paper. We show first the temporal behavior of these measurements. Secondly, if data are gathered by heliolatitude, the shape of the Sun differs from a perfect ellipsoid and shows solar distortions. We compare these results with others obtained with the heliometer at the Pic du Midi observatory in France. The comparison show a similitude in the shape with a bulge near the equator extending on 20-30 degrees followed by a depression at higher latitude near 60-70 degrees. These solar distortions needs to be confirmed by future space measurements (PICARD microsatellite) but it already raises the problem of a better understanding of the physics in the sub-surface layers.

  16. Solar radius change between 1925 and 1979

    NASA Technical Reports Server (NTRS)

    Sofia, S.; Dunham, D. W.; Dunham, J. B.; Fiala, A. D.

    1983-01-01

    From an analysis of numerous reports from different locations on the duration of totality of the solar eclipses on January 24, 1925, and February 26, 1979, it is found that the solar radius at the earlier date was 0.5 arcsec (or 375 km) larger than at the later date. The correction to the standard solar radius found for each eclipse is different when different subsets of the observations are used (for example, edge of path of totality timings compared with central timings). This is seen as suggesting the existence of systematic inaccuracies in our knowledge of the lunar figure. The differences between the corrections for both eclipses, however, are very similar for all subsets considered, indicating that changes of the solar size may be reliably inferred despite the existence of the lunar figure errors so long as there is proper consideration of the distribution of the observations. These results are regarded as strong evidence in support of the occurrence of solar radius changes on shorter than evolutionary time scales.

  17. Measurement of the Radius of Neutron Stars

    NASA Astrophysics Data System (ADS)

    Guillot, Sebastien

    2012-07-01

    A physical understanding of the behavior of cold ultra-dense matter -- at and above nuclear density -- can only be achieved by the study of neutron stars. The recent 1.97+/-0.04 Msun measurement for PSR 1614-2230 suggests that strange quark matter and hyperons/kaons condensate equations of state (EoSs) are disfavored, in favor of hadronic EoSs. Over much of the neutron star mass-radius parameter space, the latter EoSs produce lines of nearly constant radii (within about 10%). We present a simultaneous spectral analysis of several globular cluster quiescent low-mass x-ray binaries where we require the radius to be the same among all neutron stars analyzed. Our (preliminary) results suggest a neutron star radius much smaller than previously reported, in the range 7.5-10 km (90% confidence). The Markov-Chain Monte-Carlo method and the Bayesian approach developed in this analysis permits including uncertainties in the distance, in the hydrogen column density, and possible contributions to the spectra due to unmodelled spectrally hard components.

  18. Measurement of the Radius of Neutron Stars

    NASA Astrophysics Data System (ADS)

    Guillot, Sebastien; Rutledge, R. E.; Servillat, M.; Webb, N.

    2013-01-01

    A physical understanding of the behavior of cold ultra dense matter - at and above nuclear density - can only be achieved by the study of neutron stars. The recent 1.97 ± 0.04 M⊙ measurement for PSR 1614-2230 suggests that strange quark matter and hyperons/kaons condensate equations of state (EoSs) are disfavored, in favor of hadronic EoSs. Over much of the neutron star mass-radius parameter space, the latter EoSs produce lines of nearly constant radii (within about 10%). We present a simultaneous spectral analysis of several globular cluster quiescent low-mass X-ray binaries where we require the radius to be the same among all neutron stars analyzed. Our (preliminary) results suggest a neutron star radius much smaller than previously reported, in the range 7.5-10 km (90% confidence). The Markov-Chain Monte-Carlo method and the Bayesian approach developed in this analysis permits including uncertainties in the distance, in the hydrogen column density, and possible contributions to the spectra due to unmodeled spectrally hard components.

  19. Electrode radius predicts lesion radius during radiofrequency energy heating. Validation of a proposed thermodynamic model

    SciTech Connect

    Haines, D.E.; Watson, D.D.; Verow, A.F. )

    1990-07-01

    Myocardial heating by transcatheter delivery of radiofrequency (RF) energy has been proposed as an effective means of arrhythmia ablation. A thermodynamic model describing the radial temperature gradient at steady state during RF-induced heating is proposed. If one assumes that RF power output is adjusted to maintain a constant electrode-tissue interface temperature at all times, then this thermodynamic model predicts that the radius of the RF-induced lesion will be directly proportional to the electrode radius. A total of 76 RF-induced lesions were created in a model of isolated canine right ventricular free wall perfused and superfused with oxygenated Krebs-Henseleit buffer. Electrode radius was varied between 0.75 and 2.25 mm. RF energy (500 kHz) was delivered for 90 seconds, and the power output was adjusted to maintain a constant electrode-tissue interface temperature of 60 degrees C. A strong linear correlation was observed between electrode radius and lesion radius in two dimensions: transverse (p = 0.0001, r = 0.85) and transmural (p = 0.0001, r = 0.89). With these data, the temperature correlation with irreversible myocardial injury in this model was calculated at 46.6-48.8 degrees C. Therefore, the proposed thermodynamic model closely predicts the observed relation between electrode radius and lesion size during RF myocardial heating.

  20. External fixation of distal radius fractures.

    PubMed

    Slutsky, David J

    2007-12-01

    External fixation has been used for the treatment of distal radius fractures for more than 50 years. Although the fixator configurations have undergone considerable modification over time, the type of fixator itself is not as important as the underlying principles that provide the foundation for external fixation. Although volar plate fixation is currently in vogue, the indications for external fixation remain largely unchanged. Newer fixator designs have also expanded the traditional usage to include nonbridging applications that allow early wrist motion. The following discussion focuses on the myriad uses for external fixation as well as the shortcomings and potential pitfalls. PMID:18070654

  1. [Arthroscopic treatment of distal radius fracture].

    PubMed

    Lindau, T

    2006-11-01

    The orthopaedic surgeons cannot predict the functional results after a distal intra articular radius fracture. The intra-articular incongruity of more than 1 mm is associated with the development of secondary osteoarthrosis. The wrist arthroscopy became an essential help for the reduction of these fractures. The hand is normally in an upright position with a traction of approximately 4-5 kg which facilitates the reduction of the extra-articular fracture component. It is possible to use a technique of horizontal traction. The arthroscopy allows the reduction and control of the fixing of the various fragments, but also the treatment associated lesions associated. One randomized study, which compared 34 arthroscopically treated fractures with 48 openly treated, concluded that the arthroscopy-treated group had better outcome, better reduction, better grip strength and better range of motion than the openly treated group. The treatment of intra articular distal radius fractures with arthroscopic assistance is thus the guaranteeing of the most anatomical reduction of articular surface. It allows the diagnosis and the treatment of the associated lesions, decreases the peripheral fibrous scars of soft tissues by avoiding initially extensive approaches and finally gives better functional results. PMID:17361885

  2. [Arthroscopic treatment of distal radius fracture.

    PubMed

    Lindau, T

    2006-11-01

    The orthopaedic surgeons cannot predict the functional results after a distal intra articular radius fracture. The intra-articular incongruity of more than 1 mm is associated with the development of secondary osteoarthrosis. The wrist arthroscopy became an essential help for the reduction of these fractures. The hand is normally in an upright position with a traction of approximately 4-5 kg which facilitates the reduction of the extra-articular fracture component. It is possible to use a technique of horizontal traction. The arthroscopy allows the reduction and control of the fixing of the various fragments, but also the treatment associated lesions associated. One randomized study, which compared 34 arthroscopically treated fractures with 48 openly treated, concluded that the arthroscopy-treated group had better outcome, better reduction, better grip strength and better range of motion than the openly treated group. The treatment of intra articular distal radius fractures with arthroscopic assistance is thus the guaranteeing of the most anatomical reduction of articular surface. It allows the diagnosis and the treatment of the associated lesions, decreases the peripheral fibrous scars of soft tissues by avoiding initially extensive approaches and finally gives better functional results. PMID:17349390

  3. Ultrasound-Assisted Distal Radius Fracture Reduction

    PubMed Central

    Socransky, Steve; Skinner, Andrew; Bromley, Mark; Smith, Andrew; Anawati, Alexandre; Middaugh, Jeff; Ross, Peter

    2016-01-01

    Introduction Closed reduction of distal radius fractures (CRDRF) is a commonly performed emergency department (ED) procedure. The use of point-of-care ultrasound (PoCUS) to diagnose fractures and guide reduction has previously been described. The primary objective of this study was to determine if the addition of PoCUS to CRDRF changed the perception of successful initial reduction. This was measured by the rate of further reduction attempts based on PoCUS following the initial clinical determination of achievement of best possible reduction. Methods  We performed a multicenter prospective cohort study, using a convenience sample of adult ED patients presenting with a distal radius fracture to five Canadian EDs. All study physicians underwent standardized PoCUS training for fractures. Standard clinically-guided best possible fracture reduction was initially performed. PoCUS was then used to assess the reduction adequacy. Repeat reduction was performed if deemed indicated. A post-reduction radiograph was then performed. Clinician impression of reduction adequacy was scored on a 5 point Likert scale following the initial clinically-guided reduction and following each PoCUS scan and the post-reduction radiograph. Results  There were 131 patients with 132 distal radius fractures. Twelve cases were excluded prior to analysis. There was no significant difference in the assessment of the initial reduction status by PoCUS as compared to the clinical exam (mean score: 3.8 vs. 3.9; p = 0.370; OR 0.89; 95% CI 0.46 to 1.72; p = 0.87). Significantly fewer cases fell into the uncertain category with PoCUS than with clinical assessment (2 vs 12; p = 0.008). Repeat reduction was performed in 49 patients (41.2%). Repeat reduction led to a significant improvement (p < 0.001) in the PoCUS determined adequacy of reduction (mean score: 4.3 vs 3.1; p < 0.001). In this group, the odds ratio for adequate vs. uncertain or inadequate reduction assessment using PoCUS was 12.5 (95% CI 3

  4. Ultrasound-Assisted Distal Radius Fracture Reduction.

    PubMed

    Socransky, Steve; Skinner, Andrew; Bromley, Mark; Smith, Andrew; Anawati, Alexandre; Middaugh, Jeff; Ross, Peter; Atkinson, Paul

    2016-01-01

    Introduction Closed reduction of distal radius fractures (CRDRF) is a commonly performed emergency department (ED) procedure. The use of point-of-care ultrasound (PoCUS) to diagnose fractures and guide reduction has previously been described. The primary objective of this study was to determine if the addition of PoCUS to CRDRF changed the perception of successful initial reduction. This was measured by the rate of further reduction attempts based on PoCUS following the initial clinical determination of achievement of best possible reduction. Methods  We performed a multicenter prospective cohort study, using a convenience sample of adult ED patients presenting with a distal radius fracture to five Canadian EDs. All study physicians underwent standardized PoCUS training for fractures. Standard clinically-guided best possible fracture reduction was initially performed. PoCUS was then used to assess the reduction adequacy. Repeat reduction was performed if deemed indicated. A post-reduction radiograph was then performed. Clinician impression of reduction adequacy was scored on a 5 point Likert scale following the initial clinically-guided reduction and following each PoCUS scan and the post-reduction radiograph. Results  There were 131 patients with 132 distal radius fractures. Twelve cases were excluded prior to analysis. There was no significant difference in the assessment of the initial reduction status by PoCUS as compared to the clinical exam (mean score: 3.8 vs. 3.9; p = 0.370; OR 0.89; 95% CI 0.46 to 1.72; p = 0.87). Significantly fewer cases fell into the uncertain category with PoCUS than with clinical assessment (2 vs 12; p = 0.008). Repeat reduction was performed in 49 patients (41.2%). Repeat reduction led to a significant improvement (p < 0.001) in the PoCUS determined adequacy of reduction (mean score: 4.3 vs 3.1; p < 0.001). In this group, the odds ratio for adequate vs. uncertain or inadequate reduction assessment using PoCUS was 12.5 (95% CI 3

  5. [Distal radius fractures: conservative or surgical treatment?].

    PubMed

    Mark, G; Ryf, C

    1993-07-01

    The "classical" Colles fracture of the distal radius is the most common fracture in the adult. In order to reduce the still rather high rate of permanent disability, this fracture involving a functionally important joint requires accurate reduction. The AO-fracture classification introduced by Müller not only defines the severity of an injury, but also allows for decision-making as to the most adequate treatment. Besides the purely conservative management by closed reduction and plaster cast for the type-A fractures, we have a number of other treatment modalities for the more complex-B and C-type fractures, such as closed reduction and percutaneous K-wire application or the use of the small external fixator as well as open reduction and internal fixation by plates and screws for a few selected indications. PMID:8211844

  6. Understanding the mass-radius relation for sub-Neptunes: radius as a proxy for composition

    SciTech Connect

    Lopez, Eric D.; Fortney, Jonathan J.

    2014-09-01

    Transiting planet surveys like Kepler have provided a wealth of information on the distribution of planetary radii, particularly for the new populations of super-Earth- and sub-Neptune-sized planets. In order to aid in the physical interpretation of these radii, we compute model radii for low-mass rocky planets with hydrogen-helium envelopes. We provide model radii for planets 1-20 M {sub ⊕}, with envelope fractions 0.01%-20%, levels of irradiation 0.1-1000 times Earth's, and ages from 100 Myr to 10 Gyr. In addition we provide simple analytic fits that summarize how radius depends on each of these parameters. Most importantly, we show that at fixed H/He envelope fraction, radii show little dependence on mass for planets with more than ∼1% of their mass in their envelope. Consequently, planetary radius is to a first order a proxy for planetary composition, i.e., H/He envelope fraction, for Neptune- and sub-Neptune-sized planets. We recast the observed mass-radius relationship as a mass-composition relationship and discuss it in light of traditional core accretion theory. We discuss the transition from rocky super-Earths to sub-Neptune planets with large volatile envelopes. We suggest ∼1.75 R {sub ⊕} as a physically motivated dividing line between these two populations of planets. Finally, we discuss these results in light of the observed radius occurrence distribution found by Kepler.

  7. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to...

  8. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to...

  9. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to...

  10. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Corneal radius measuring device. 886.1450 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius measuring device is an AC-powered device intended to...

  11. Photospheric Radius Expansion During Magnetar Bursts

    NASA Astrophysics Data System (ADS)

    Watts, Anna L.; Kouveliotou, Chryssa; van der Horst, Alexander J.; Göǧüş, Ersin; Kaneko, Yuki; van der Klis, Michiel; Wijers, Ralph A. M. J.; Harding, Alice K.; Baring, Matthew G.

    2010-08-01

    On 2008 August 24 the new magnetar SGR 0501+4516 (discovered by Swift) emitted a bright burst with a pronounced double-peaked structure in hard X-rays, reminiscent of the double-peaked temporal structure seen in some bright thermonuclear bursts on accreting neutron stars. In the latter case this is due to Photospheric Radius Expansion (PRE): when the flux reaches the Eddington limit, the photosphere expands and cools so that emission becomes softer and drops temporarily out of the X-ray band, re-appearing as the photosphere settles back down. We consider the factors necessary to generate double-peaked PRE events, and show that such a mechanism could plausibly operate in magnetar bursts despite the vastly different emission process. Identification of the magnetic Eddington limit in a magnetar would constrain magnetic field and distance and could, in principle, enable a measurement of gravitational redshift. It would also locate the emitting region at the neutron star surface, constraining the burst trigger mechanism. Conclusive confirmation of PRE events will require more detailed radiative models for bursts. However, for SGR 0501+4516 the predicted critical flux (using the magnetic field strength inferred from timing and the distance suggested by its probable location in the Perseus arm of our Galaxy) is consistent with that observed in the August 24 burst.

  12. Experimental study of finite Larmor radius effects

    SciTech Connect

    Struve, K.W.

    1980-08-01

    Linear Z-pinches in Ar, Kr, Xe, N/sub 2/, and He are experimentally studied in regimes where strong finite Larmor radius effects could provide a significant stabilizing effect. Scaling arguments show that for deuterium such a pinch has an electron line density of order 2 x 10/sup 15//cm. For higher Z plasmas a higher line density is allowed, the exact value of which depends on the average ion charge. The pinch is formed by puffing gas axially through the cathode towards the anode of an evacuated pinch chamber. When the gas reaches the anode, the pinch bank is fired. The pinch current rises in 2 to 3 ..mu..sec to a maximum of 100 to 200 kA. The pinch bank capacitance is 900 ..mu..F, and the external inductance is 100 nH. Additionally, the bank is fused to increase dI/dt. The primary diagnostics are a framing camera, a spatially resolved Mach-Zehnder interferometer, and X-ray absorption.

  13. Tidal radius estimates for three open clusters

    NASA Astrophysics Data System (ADS)

    Danilov, V. M.; Loktin, A. V.

    2015-10-01

    A new method is developed for estimating tidal radii and masses of open star clusters (OCL) based on the sky-plane coordinates and proper motions and/or radial velocities of cluster member stars. To this end, we perform the correlation and spectral analysis of oscillations of absolute values of stellar velocity components relative to the cluster mass center along three coordinate planes and along each coordinate axis in five OCL models. Mutual correlation functions for fluctuations of absolute values of velocity field components are computed. The spatial Fourier transform of the mutual correlation functions in the case of zero time offset is used to compute wavenumber spectra of oscillations of absolute values of stellar velocity components. The oscillation spectra of these quantities contain series of local maxima at equidistant wavenumber k values. The ratio of the tidal radius of the cluster to the wavenumber difference Δ k of adjacent local maxima in the oscillation spectra of absolute values of velocity field components is found to be the same for all five OCL models. This ratio is used to estimate the tidal radii and masses of the Pleiades, Praesepe, and M67 based on the proper motions and sky-plane coordinates of the member stars of these clusters. The radial dependences of the absolute values of the tangential and radial projections of cluster star velocities computed using the proper motions relative to the cluster center are determined, along with the corresponding autocorrelation functions and wavenumber spectra of oscillations of absolute values of velocity field components. The Pleiades virial mass is estimated assuming that the cluster is either isolated or non-isolated. Also derived are the estimates of the Pleiades dynamical mass assuming that it is non-stationary and non-isolated. The inferred Pleiades tidal radii corresponding to these masses are reported.

  14. Contribution to the cloud droplet effective radius parameterization

    SciTech Connect

    Pontikis, C.; Hicks, E. )

    1992-11-01

    An analytic cloud droplet effective radius expression is derived and validated by using field experiment microphysical data. This expression shows that the effective radius depends simultaneously upon the cloud liquid water content, droplet concentration and droplet spectral dispersion. It further suggests that the variability in these parameters present at all scales, due to turbulent mixing and secondary droplet activation, could limit the accuracy of the effective radius parameterizations used in climate models. 12 refs.

  15. Discharge coefficients of cooling holes with radiused and chamfered inlets

    NASA Astrophysics Data System (ADS)

    Hay, N.; Spencer, A.

    1991-06-01

    The flow of cooling air within the internal passages of gas turbines is controlled and metered using holes in disks and casings. The effects of inlet radiusing and chamfering of these holes on the discharge coefficient are discussed. Experimental results for a range of radiusing and chamfering ratios for holes of different length to diameter ratios are presented, covering the range of pressure ratios of practical interest. The results indicate that radiusing and chamfering are both beneficial in increasing the discharge coefficient. Increases of 10-30 percent are possible. Chamfered holes give the more desirable performance characteristics in addition to being easier to produce than radiused holes.

  16. Improving optical bench radius measurements using stage error motion data

    SciTech Connect

    Schmitz, Tony L.; Gardner, Neil; Vaughn, Matthew; Medicus, Kate; Davies, Angela

    2008-12-20

    We describe the application of a vector-based radius approach to optical bench radius measurements in the presence of imperfect stage motions. In this approach, the radius is defined using a vector equation and homogeneous transformation matrix formulism. This is in contrast to the typical technique, where the displacement between the confocal and cat's eye null positions alone is used to determine the test optic radius. An important aspect of the vector-based radius definition is the intrinsic correction for measurement biases, such as straightness errors in the stage motion and cosine misalignment between the stage and displacement gauge axis, which lead to an artificially small radius value if the traditional approach is employed. Measurement techniques and results are provided for the stage error motions, which are then combined with the setup geometry through the analysis to determine the radius of curvature for a spherical artifact. Comparisons are shown between the new vector-based radius calculation, traditional radius computation, and a low uncertainty mechanical measurement. Additionally, the measurement uncertainty for the vector-based approach is determined using Monte Carlo simulation and compared to experimental results.

  17. The Origin of the Ionic-Radius Ratio Rules

    ERIC Educational Resources Information Center

    Jensen, William B.

    2010-01-01

    In response to a reader query, this article traces the origins of the ionic-radius ratio rules and their incorrect attribution to Linus Pauling in the chemical literature and to Victor Goldschmidt in the geochemical literature. In actual fact, the ionic-radius ratio rules were first proposed within the context of the coordination chemistry…

  18. Determination of Radius of Curvature for Teeth With Cycloid Profile

    NASA Astrophysics Data System (ADS)

    Shatalov, E. V.; Efremenkov, E. A.; Shibinskiy, K. G.

    2016-04-01

    In the article the geometric determination of curvature radius is considered for teeth with cycloid profile. The equations are obtained for the determination of a radius of curvature with point coordinates of a cycloid profile. The conditions of convexo-concavity of a teeth profile are defined for transmission with intermediate rollers.

  19. Decreasing the spectral radius of a graph by link removals.

    PubMed

    Van Mieghem, Piet; Stevanović, Dragan; Kuipers, Fernando; Li, Cong; van de Bovenkamp, Ruud; Liu, Daijie; Wang, Huijuan

    2011-07-01

    The decrease of the spectral radius, an important characterizer of network dynamics, by removing links is investigated. The minimization of the spectral radius by removing m links is shown to be an NP-complete problem, which suggests considering heuristic strategies. Several greedy strategies are compared, and several bounds on the decrease of the spectral radius are derived. The strategy that removes that link l=i~j with largest product (x(1))(i)(x(1))(j) of the components of the eigenvector x(1) belonging to the largest adjacency eigenvalue is shown to be superior to other strategies in most cases. Furthermore, a scaling law where the decrease in spectral radius is inversely proportional to the number of nodes N in the graph is deduced. Another sublinear scaling law of the decrease in spectral radius versus the number m of removed links is conjectured. PMID:21867251

  20. On the Variation of Solar Radius in Rotation Cycles

    NASA Astrophysics Data System (ADS)

    Qu, Z. N.; Kong, D. F.; Xiang, N. B.; Feng, W.

    2015-01-01

    The Date Compensated Discrete Fourier Transform and CLEANest algorithm are used to study the temporal variations of the solar radius observed at Rio de Janeiro Observatory from 1998 March 2 to 2009 November 6. The CLEANest spectra show several significant periodicities around 400, 312, 93.5, 86.2, 79.4, 70.9, 53.2, and 26.3 days. Then, combining the data on the daily solar radius measured at Calern Observatory and Rio de Janeiro Observatory and the corresponding daily sunspot areas, we study the short-term periodicity of the solar radius and the role of magnetic field in the variation of the solar radius. The rotation period of the daily solar radius is determined to be statistically significant. Moreover, its temporal evolution is anti-phase with that of sunspot activity, and it is found anti-phase with solar activity. Generally, the stronger solar activity is, the more obvious is the anti-phase relation of radius with solar activity. This indicates that strong magnetic fields have a greater inhibitive effect than weak magnetic fields on the variation of the radius.

  1. ON THE VARIATION OF SOLAR RADIUS IN ROTATION CYCLES

    SciTech Connect

    Qu, Z. N.; Kong, D. F.; Xiang, N. B.; Feng, W.

    2015-01-10

    The Date Compensated Discrete Fourier Transform and CLEANest algorithm are used to study the temporal variations of the solar radius observed at Rio de Janeiro Observatory from 1998 March 2 to 2009 November 6. The CLEANest spectra show several significant periodicities around 400, 312, 93.5, 86.2, 79.4, 70.9, 53.2, and 26.3 days. Then, combining the data on the daily solar radius measured at Calern Observatory and Rio de Janeiro Observatory and the corresponding daily sunspot areas, we study the short-term periodicity of the solar radius and the role of magnetic field in the variation of the solar radius. The rotation period of the daily solar radius is determined to be statistically significant. Moreover, its temporal evolution is anti-phase with that of sunspot activity, and it is found anti-phase with solar activity. Generally, the stronger solar activity is, the more obvious is the anti-phase relation of radius with solar activity. This indicates that strong magnetic fields have a greater inhibitive effect than weak magnetic fields on the variation of the radius.

  2. Thermoconvective vortices in a cylindrical annulus with varying inner radius

    NASA Astrophysics Data System (ADS)

    Castaño, D.; Navarro, M. C.; Herrero, H.

    2014-12-01

    This paper shows the influence of the inner radius on the stability and intensity of vertical vortices, qualitatively similar to dust devils and cyclones, generated in a cylindrical annulus non-homogeneously heated from below. Little relation is found between the intensity of the vortex and the magnitude of the inner radius. Strong stable vortices can be found for both small and large values of the inner radius. The Rankine combined vortex structure, that characterizes the tangential velocity in dust devils, is clearly observed when small values of the inner radius and large values of the ratio between the horizontal and vertical temperature differences are considered. A contraction on the radius of maximum azimuthal velocity is observed when the vortex is intensified by thermal mechanisms. This radius becomes then nearly stationary when frictional force balances the radial inflow generated by the pressure drop in the center, despite the vortex keeps intensifying. These results connect with the behavior of the radius of the maximum tangential wind associated with a hurricane.

  3. Thermoconvective vortices in a cylindrical annulus with varying inner radius.

    PubMed

    Castaño, D; Navarro, M C; Herrero, H

    2014-12-01

    This paper shows the influence of the inner radius on the stability and intensity of vertical vortices, qualitatively similar to dust devils and cyclones, generated in a cylindrical annulus non-homogeneously heated from below. Little relation is found between the intensity of the vortex and the magnitude of the inner radius. Strong stable vortices can be found for both small and large values of the inner radius. The Rankine combined vortex structure, that characterizes the tangential velocity in dust devils, is clearly observed when small values of the inner radius and large values of the ratio between the horizontal and vertical temperature differences are considered. A contraction on the radius of maximum azimuthal velocity is observed when the vortex is intensified by thermal mechanisms. This radius becomes then nearly stationary when frictional force balances the radial inflow generated by the pressure drop in the center, despite the vortex keeps intensifying. These results connect with the behavior of the radius of the maximum tangential wind associated with a hurricane. PMID:25554036

  4. Study of a non-intrusive electron beam radius diagnostic

    SciTech Connect

    Kwan, T.J.T.; DeVolder, B.G.; Goldstein, J.C.; Snell, C.M.

    1997-12-01

    The authors have evaluated the usefulness and limitation of a non-intrusive beam radius diagnostic which is based on the measurement of the magnetic moment of a high-current electron beam in an axisymmetric focusing magnetic field, and relates the beam root-mean-square (RMS) radius to the change in magnetic flux through a diamagnetic loop encircling the beam. An analytic formula that gives the RMS radius of the electron beam at a given axial position and a given time is derived and compared with results from a 2-D particle-in-cell code. The study has established criteria for its validity and optimal applications.

  5. Primary nonunion of the distal radius fractures in healthy children.

    PubMed

    Song, Kwang Soon; Lee, Si Wook; Bae, Ki Cheor; Yeon, Chang Jin; Naik, Premal

    2016-03-01

    There are no published case series of nonunion of distal radius fractures in healthy children because of the rarity of its occurrence. We searched for all reported cases of this condition in Pubmed, Google scholar, and SCOPUS. We found three series, which included one previously reported by our group. The aim of the present study was to define the predisposing factors leading to nonunion after treatment of distal radius fractures in healthy children. We also aimed to emphasize that nonunion should be included in the list of complications of distal radius fractures in children and be mentioned in the textbook of pediatric trauma. PMID:26583931

  6. New Precision Measurement for Proton Zemach Radius with Laser Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ma, Y.; Ishida, K.; Iwasaki, M.; Matsuzaki, Y.; Oishi, Y.; Okada, S.; Sato, M.; Midorikawa, K.; Saito, N.; Wada, S.; Aikawa, S.; Kanda, S.; Matsuda, Y.; Tanaka, K.; Takamine, A.

    2016-02-01

    In this proceeding, a new proposal aiming to improve the precision of the proton Zemach radius will be presented. A circularly polarized laser will be shed on a sample of muonic hydrogen in its ground state. By observing the maximum muon decay asymmetry during scanning laser wave length, the ground-state hyperfine splitting energy can be identified, which is directly related to Zemach radius.citedupays The precision of Zemach radius by this measurement is estimated to be three times better compared to PSI experiment. This result will contribute to the solution of proton size puzzle.

  7. An Asian perspective on the management of distal radius fractures.

    PubMed

    Sebastin, Sandeep J; Chung, Kevin C

    2012-05-01

    There is limited data regarding the epidemiology, pathology, and management of distal radius fractures from centers in Asia. The advanced economies in Asia include Hong Kong, Japan, Korea, Singapore, and Taiwan, whereas the prominent emerging economies are China, India, Malaysia, Philippines, and Thailand. This article examines the available epidemiological data from Asia, compares the management of distal radius fractures in the advanced and emerging Asian economies and how they compare with the current management in the west. It concludes by offering solutions for improving outcomes of distal radius fractures in Asia. PMID:22554658

  8. An Asian Perspective on the Management of Distal Radius Fractures

    PubMed Central

    Sebastin, Sandeep J.; Chung, Kevin C.

    2012-01-01

    Synopsis There is little data with regards to the epidemiology, pathology, or management of distal radius fractures from centers in Asia. Asia includes five advanced economies, namely Hong Kong SAR, Japan, Korea, Singapore, and Taiwan and a number of emerging economies prominent among which are China, India, Malaysia, Philippines, and Thailand. This article examines the available epidemiological data from Asia, and compares the management of distal radius fractures in the advanced and emerging Asian economies and how they match up to the current management in the west. It concludes by offering solutions for improving outcomes of distal radius fractures in both the advanced and emerging economies of Asia. PMID:22554658

  9. 21 CFR 886.1450 - Corneal radius measuring device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device... small, hand held, single tube penscope or eye gauge magnifier. (b) Classification. Class I...

  10. Laser confocal radius measurement method for unpolished spheres.

    PubMed

    Wang, Xu; Zhao, Weiqian; Qiu, Lirong; Yang, Shuai; Wang, Zhongyu

    2016-06-10

    A laser confocal radius measurement method for unpolished spheres (CRMUS) is proposed for measuring the radius of an unpolished sphere during optical sphere processing. CRMUS uses the laser confocal focusing technique to accurately identify the cat's eye and confocal positions of the unpolished sphere, and then uses the distance between the cat's eye and confocal positions measured by a distance measurement interferometer to derive the radius. The partially coherent optical theoretical model of the CRMUS derived indicates that the CRMUS is able to measure the radius of the unpolished sphere with a roughness of less than 0.15 μm. Using an unpolished sphere made of Schott BK7 as the test sphere, experimental results indicate that the CRMUS has a relative expanded uncertainty of less than 20 ppm. The CRMUS could greatly increase processing efficiency. PMID:27409012

  11. Fixed Lunate Flexion Deformity in Distal Radius Fractures.

    PubMed

    Lee, Sanglim; Yu, Jae-Ha; Jeon, Suk Ha

    2016-06-01

    Carpal malalignments in malunion of distal radius fracture are considered as an adaptive response of the carpus to loss of normal architecture of the distal radius. This condition leads to mechanical overload, ligament attenuation and progressive dynamic instability around the wrist joint. Radial corrective osteotomy is suggested as a treatment option of carpal malalignment after distal radius malunion. In radiocarpal malalignment, the lunate is usually observed in flexion in contrast to its extension posture in the more common midcarpal malalignment. We report two cases of fixed lunate flexion deformity after a distal radius fracture, in which reduction and fixation of fresh fracture or corrective osteotomy of malunion were not successful. Arthritic changes were observed in the radiolunate joint on arthroscopy. Thus, fixed flexion deformity of the lunate might be associated with posttraumatic arthritic change in the radiolunate joint. PMID:27247752

  12. Fixed Lunate Flexion Deformity in Distal Radius Fractures

    PubMed Central

    Lee, Sanglim; Yu, Jae-Ha

    2016-01-01

    Carpal malalignments in malunion of distal radius fracture are considered as an adaptive response of the carpus to loss of normal architecture of the distal radius. This condition leads to mechanical overload, ligament attenuation and progressive dynamic instability around the wrist joint. Radial corrective osteotomy is suggested as a treatment option of carpal malalignment after distal radius malunion. In radiocarpal malalignment, the lunate is usually observed in flexion in contrast to its extension posture in the more common midcarpal malalignment. We report two cases of fixed lunate flexion deformity after a distal radius fracture, in which reduction and fixation of fresh fracture or corrective osteotomy of malunion were not successful. Arthritic changes were observed in the radiolunate joint on arthroscopy. Thus, fixed flexion deformity of the lunate might be associated with posttraumatic arthritic change in the radiolunate joint. PMID:27247752

  13. LONG-TERM PERIODICITY VARIATIONS OF THE SOLAR RADIUS

    SciTech Connect

    Qu, Z. N.; Xie, J. L.

    2013-01-01

    In order to study the long-term periodicity variations of the solar radius, daily solar radius data from 1978 February to 2000 September at the Calern Observatory are used. Continuous observations of the solar radius are difficult due to the weather, seasonal effects, and instrument characteristics. Thus, to analyze these data, we first use the Dixon criterion to reject suspect values, then we measure the cross-correlation between the solar radius and sunspot numbers. The result indicates that the solar radius is in complete antiphase with the sunspot numbers and shows lead times of 74 months relative to the sunspot numbers. The Lomb-Scargle and date compensated discrete Fourier transform methods are also used to investigate the periodicity of the solar radius. Both methods yield similar significance periodicities around {approx}1 yr, {approx}2.6 yr, {approx}3.6 yr, and {approx}11 yr. Possible mechanisms for these periods are discussed. The possible physical cause of the {approx}11 yr period is the cyclic variation of the magnetic pressure of the concentrated flux tubes at the bottom of the solar convection zone.

  14. Isolated Diaphyseal Fractures of the Radius in Skeletally Immature Patients

    PubMed Central

    Guitton, Thierry G.; Van Dijk, Niek C.; Raaymakers, Ernst L.

    2009-01-01

    Diaphyseal radius fractures without associated ulna fracture or radioulnar dislocation (isolated fracture of the radius) are recognized in adults but are rarely described in skeletally immature patients. A search of our database (1974–2002) identified 17 pediatric patients that had an isolated fracture of the radius. Among the 13 patients with at least 1 year follow-up, ten were treated with manipulative reduction and immobilization in an above elbow cast and three had initial operative treatment with plate and screw fixation. These 13 patients were evaluated for an average of 18 months (range, 12 to 45 months) after injury using the system of Price and colleagues. The incidence of isolated diaphyseal radius fractures in skeletally immature patients was 0.56 per year in our database and represented 27% of the 63 patients with a diaphyseal forearm fracture. All 13 patients, with at least 1 year follow-up, regained full elbow flexion and extension and full forearm rotation. According to the classification system of Price, all 13 patients (100%) had an excellent result. As in adults, isolated radius fractures seem to occur in children more frequently than previously appreciated. Treatment of isolated radius fractures in skeletally immature patients has a low complication rate, and excellent functional outcomes are the rule. PMID:19859772

  15. Distal Radius Radiographic Indices and Perilunate Fracture Dislocation

    PubMed Central

    Bagherifard, Abolfazl; Jafari, Davod; Keihan Shokouh, Hassan; Motavallian, Ebrahim; Najd Mazhar, Farid

    2016-01-01

    Background Distal radius radiographic indices may play a role as risk factors in pathogenesis of Kienbock’s disease, scaphoid fracture and nonunion. Perilunate fracture dislocations are devastating wrist injuries, and their relationship and distal radius indices have not been addressed in the literature. Objectives The aim of this study was to evaluate the possible role of distal radius radiographic indices including radial height, radial inclination, ulnar variance and volar tilt as risk factors in the perilunate fracture dislocation injury of the wrist. Patients and Methods We studied distal radius radiographic indices including radial height, radial inclination, ulnar variance and volar tilt in 43 patients with perilunate fracture dislocations and compared them with 44 wrists in the control group. Results The mean values of the radial height, radial inclination, ulnar variance and volar tilt were 12.74 (5 - 18), 24.20 (7 - 35), -0.73 (-5 - 4) and 12.28 (2 - 20) in the patient group. These values were 12.68 (9 - 22), 23.22 (17 - 30), -0.11 (-4 - 3) and 11.05 (-3 - 20), respectively in the control group. There was no statistically significant difference between the two groups. Conclusions This study did not show that distal radius anatomical indices including the radial height, radial inclination, ulnar variance and volar tilt influence perilunate fracture dislocation as risk factors.

  16. ON THE CONSTANCY OF THE SOLAR RADIUS. III

    SciTech Connect

    Bush, R. I.; Emilio, M.; Kuhn, J. R. E-mail: memilio@uepg.b

    2010-06-20

    The Michelson Doppler Imager on board the Solar and Heliospheric Observatory satellite has operated for over a sunspot cycle. This instrument is now relatively well understood and provides a nearly continuous record of the solar radius in combination with previously developed algorithms. Because these data are obtained from above Earth's atmosphere, they are uniquely sensitive to possible long-term changes of the Sun's size. We report here on the first homogeneous, highly precise, and complete solar-cycle measurement of the Sun's radius variability. Our results show that any intrinsic changes in the solar radius that are synchronous with the sunspot cycle must be smaller than 23 mas peak to peak. In addition, we find that the average solar radius must not be changing (on average) by more than 1.2 mas yr{sup -1}. If ground- and space-based measurements are both correct, the pervasive difference between the constancy of the solar radius seen from space and the apparent ground-based solar astrometric variability can only be accounted for by long-term changes in the terrestrial atmosphere.

  17. The radius distribution of planets around cool stars

    SciTech Connect

    Morton, Timothy D.; Swift, Jonathan

    2014-08-10

    We calculate an empirical, non-parametric estimate of the shape of the period-marginalized radius distribution of planets with periods less than 150 days using the small yet well-characterized sample of cool (T{sub eff} < 4000 K) dwarf stars in the Kepler catalog. In particular, we present and validate a new procedure, based on weighted kernel density estimation, to reconstruct the shape of the planet radius function down to radii smaller than the completeness limit of the survey at the longest periods. Under the assumption that the period distribution of planets does not change dramatically with planet radius, we show that the occurrence of planets around these stars continues to increase to below 1 R{sub ⊕}, and that there is no strong evidence for a turnover in the planet radius function. In fact, we demonstrate using many iterations of simulated data that a spurious turnover may be inferred from data even when the true distribution continues to rise toward smaller radii. Finally, the sharp rise in the radius distribution below ∼3 R{sub ⊕} implies that a large number of planets await discovery around cool dwarfs as the sensitivities of ground-based transit surveys increase.

  18. The Mass - Radius Relation of Giant Gas Planets

    NASA Astrophysics Data System (ADS)

    Çelik Orhan, Zeynep; Kayhan, Cenk; Yildiz, Mutlu

    2016-07-01

    Thanks to CoRoT and Kepler space telescope, the thousand of exoplanets have been discovered. The only observational construct on planetary interior is planetary radius. Mass-radius relation is widely studied in the literature. Many mechanisms have been suggested in the literature to explain the inflated radii of these planets. In this study, our aim is to consider planet and host star interaction and assess the basic mechanisms responsible for excess in radius of transiting giant gas planets. We show that there is much more definite relation between radius and energy per gram per second (log (l- )). There is a good linear relation between planetary radius and log (l- ) for log (l- /l0 ) < 3.75. The relation changes if log (l- /l0 ) > 3.5. There is a relatively clump for the range log (l- /l0 ) > 3.75. The reason for the change in the relation may be related with the structure of the heated part of the planets. We focus on these inflated planet.

  19. Evidence for a large radius of the 11Be projectile

    NASA Astrophysics Data System (ADS)

    So, W. Y.; Choi, K. S.; Cheoun, Myung-Ki; Kim, K. S.

    2016-05-01

    We investigate ratios of the elastic scattering cross section to Rutherford cross section, PE, and angular distributions of breakup cross section by using an optical model which exploits various long-range dynamic polarization potentials as well as short-range nuclear bare potentials for the 11Be projectile. From these simultaneous analyses, we extract a large radius of a halo projectile from the experimental data for PE and the angular distribution of the breakup cross section of the 11Be + 64Zn and 11 + 120Sn systems. It results from the fact that a large radius for the long-range nuclear potential is more reasonable for properly explaining these data simultaneously. The extracted reduced interaction radius turns out to be r0=3.18 ˜3.61 fm for 11Be nucleus, which is larger than the conventional value of r0=1.1 ˜1.5 fm used in the standard radius form R =r0A1 /3 . Furthermore, the larger radius as well as the normalization constant N is shown to be important for understanding Coulomb dipole strength distribution.

  20. Solar radius measurements with the space instrument HMI (SDO)

    NASA Astrophysics Data System (ADS)

    Irbah, Abdanour; Hauchecorne, Alain; Meftah, Mustapha; Damé, Luc; Keckhut, Philippe

    2016-04-01

    The solar radius variations and its effects on the Earth climate are still a long scientific debate. The observed variations from ground experiments were not totally admitted and several space missions have had these measures as a goal. The high angular resolution of radius measurements and its long-term trend is however a challenge in space. The first attempts with MDI (Soho) then SODISM (PICARD) and HMI (SDO) revealed the difficulties of such measures due to the hostile environment which introduces thermal variations on the instruments all along the satellite orbit. These variations have non-negligible impacts on the optical properties of the onboard telescopes and therefore on the images and the parameters which are extracted such as the solar radius. We need then to make a posteriori corrections using the thermal housekeeping's recorded together with the data science. We present here how we make such correction on the solar radius obtained from the HMI images. We will then compare and discuss the results with the solar radius recorded at 607 nm with the ground-based instrument of PICARD.

  1. FY15 Progress Report for PL14-Lg Radius SIMS-PD1Ea: Large Radius SIMS Support / Large Radius SIMS for Nuclear Materials Analysis and Characterization

    SciTech Connect

    Zimmer, Mindy M.; Naes, Benjamin E.; Willingham, David G.; Cloutier, Janet M.

    2015-09-15

    PNNL has been procured a Cameca 1280 Large Radius Secondary Ions Mass Spectrometer (LRSIMS) from the Amtek corporation out of France. This state-of-the-art instrument is aligning PNNL to deliver to NNSA the ability to address issues from proliferation detection to nuclear archeology of reactor operation and cascade enrichment history verification pushing beyond the limits of currently available methods and instrumentation at PNNL.

  2. Hominid radius from the middle Pliocene of Lake Turkana, Kenya.

    PubMed

    Heinrich, R E; Rose, M D; Leakey, R E; Walker, A C

    1993-10-01

    A nearly complete left radius, KNM-ER 20419, was recovered from middle Pliocene sediments east of Lake Turkana, Kenya in 1988. Ape-like characteristics of the fossil include an eccentrically positioned articular fovea, relatively long radial neck, wide distal metaphysis, and large brachioradialis crest. The robustness of the radial neck in proportion to the radial head, and the semilunar shape of the distal diaphysis, however, clearly distinguish KNM-ER 20419 as hominid. The distal articular surface possesses a larger area for radius-lunate articulation than for radius and scaphoid, a radiocarpal arrangement that is associated with increased wrist adduction among quadrumanous climbers. Since this morphology is also found in hylobatids, Pongo, and other early australopithecines, it is argued to be plesiomorphic for hominoids. This further supports the argument that vertical climbing was an important locomotor behavior among both early hominoids and our more immediate prebipedal ancestors. PMID:8273826

  3. Attractor radius, a new determination criterion of predictability limit

    NASA Astrophysics Data System (ADS)

    Liu, Deqiang; Ding, Ruiqiang; Li, Jianping; Feng, Jie

    2014-05-01

    Firstly, the definition of the attractor radius was given and then the property of that the attractor radius (AR) in a given n-dimensional attractor A is a constant was proved in theory. Secondly, the SV of the square of the RMS difference was separated into two components - the systematic error and the attractor radius, and it was proved that the observed global climatological RMS (OCR) difference is not equal to 71% of the SV of the RMS difference when the systematic error is existed, however, it is always equal to 71% of the AR. Then the physical understanding of the AR and also the predictability limit determinated by it were discussed. Finally, the spatial distributions of the predictability limit calculated from CFSv2 data by different criterions were compared.

  4. Consistency of electron scattering data with a small proton radius

    NASA Astrophysics Data System (ADS)

    Griffioen, Keith; Carlson, Carl; Maddox, Sarah

    2016-06-01

    We determine the charge radius of the proton by analyzing the published low momentum transfer electron-proton scattering data from Mainz. We note that polynomial expansions of the form factor converge for momentum transfers squared below 4 mπ2 , where mπ is the pion mass. Expansions with enough terms to fit the data, but few enough not to overfit, yield proton radii smaller than the CODATA or Mainz values and in accord with the muonic atom results. We also comment on analyses using a wider range of data, and overall obtain a proton radius RE=0.840 (16 ) fm.

  5. Stability of a Wheel with Various Radius Rim

    NASA Astrophysics Data System (ADS)

    Kinugasa, Tetsuya; Yoshida, Koji

    This paper describes the dynamics and impact model of a wheel with various radius rim. The dynamics is expressed by a rst order linear ordinary dierential equation with respect to the absolute orientation of the wheel, and an analytic solution is derived. Poincaré map is also derived analytically. Stability and basin of attraction (BoA) of the Poincaré map are discussed. Finally, the analysis is validated through some numerical simulations. As a result, the rim radius aects the stability and broadens its BoA. The analysis helps understanding of not only a geometric tracking control but also many underactuated control methods for bipeds.

  6. A Unified Approach to Outcomes Assessment for Distal Radius Fractures.

    PubMed

    Waljee, Jennifer F; Ladd, Amy; MacDermid, Joy C; Rozental, Tamara D; Wolfe, Scott W

    2016-04-01

    Distal radius fractures are one of the most common upper extremity injuries. Currently, outcome assessment after treatment of these injuries varies widely with respect to the measures that are used, timing of assessment, and the end points that are considered. A more consistent approach to outcomes assessment would provide a standard by which to assess treatment options and best practices. In this summary, we review the consensus regarding outcomes assessment after distal radius fractures and propose a systematic approach that integrates performance, patient-reported outcomes, pain, complications, and radiographs. PMID:26952734

  7. The PRad experiment and the proton radius puzzle

    SciTech Connect

    Gasparian, Ashot H.

    2014-06-01

    New results from the recent muonic hydrogen experiments seriously questioned our knowledge of the proton charge radius, r_p. The new value, with its unprecedented less than sub-percent precision, is currently up to eight standard deviation smaller than the average value from all previous experiments, triggering the well-known "proton charge radius puzzle" in nuclear and atomic physics. The PRad collaboration is currently preparing a novel, magnetic-spectrometer-free ep scattering experiment in Hall B at JLab for a new independent r_p measurement to address this growing "puzzle" in physics.

  8. Proton Charge Radius (PRad) Experiment at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Peng, C.; Gao, H.

    2016-03-01

    The puzzle of proton charge radius was recently raised by the measurement of muonic hydrogen Lamb shift at Paul Scherrer Institute (PSI), whose results were seven standard deviations smaller than the CODATA recommended value. To investigate this discrepancy, the PRad experiment was proposed and approved at Thomas Jefferson National Accelerator Facility (JLab). The experiment will extract the proton charge radius with a sub-percent accuracy by measuring the cross-sections of unpolarized electronproton elastic scattering in an unprecedented low Q2 region (2×10-4 GeV2/c2).

  9. Nonlinear buckling analyses of a small-radius carbon nanotube

    NASA Astrophysics Data System (ADS)

    Liu, Ning; Wang, Yong-Gang; Li, Min; Jia, Jiao

    2014-04-01

    Carbon nanotube (CNT) was first discovered by Sumio Iijima. It has aroused extensive attentions of scholars from all over the world. Over the past two decades, we have acquired a lot of methods to synthesize carbon nanotubes and learn their many incredible mechanical properties such as experimental methods, theoretical analyses, and computer simulations. However, the studies of experiments need lots of financial, material, and labor resources. The calculations will become difficult and time-consuming, and the calculations may be even beyond the realm of possibility when the scale of simulations is large, as for computer simulations. Therefore, it is necessary for us to explore a reasonable continuum model, which can be applied into nano-scale. This paper attempts to develop a mathematical model of a small-radius carbon nanotube based on continuum theory. An Isotropic circular cross-section, Timoshenko beam model is used as a simplified mechanical model for the small-radius carbon nanotube. Theoretical part is mainly based on modified couple stress theory to obtain the numerical solutions of buckling deformation. Meanwhile, the buckling behavior of the small radius carbon nanotube is simulated by Molecular Dynamics method. By comparing with the numerical results based on modified couple stress theory, the dependence of the small-radius carbon nanotube mechanical behaviors on its elasticity constants, small-size effect, geometric nonlinearity, and shear effect is further studied, and an estimation of the small-scale parameter of a CNT (5, 5) is obtained.

  10. Multipurpose external fixator for intraarticular fracture of distal radius.

    PubMed

    Siripakarn, Yongyuth; Siripakarn, Zongyuti

    2010-12-01

    Fracture of distal radius is one of a complicated injury which can be difficult in reduction and maintaining its alignment and may result in malunion and shortening following a variety of fixation. Since Anderson's and O'neil described the use of sustain traction by extraskeletal device anchored to the radius and the first metacarpal of the hand. Vidal et al [1979] demonstrated that the ligamentotaxis could be used to reduce the fracture around the wrist, ankle, hip and knee. The external fixation frame can maintain radial length and inclination by the pullout force from the radial styloid. External fixation is useful for management of complex intraarticular fracture of distal radius. There are few types of commercially available fixator. It is important to use one that allow versatility and follow biomechanic principles of ligamentotaxis, which can be used to reduce the severe comminution and the most difficult fracture by distraction and stabilization effectively. The ideal characteristic of the external fixation are: Telescoping connecting frame fixed externally compose of two joints which can be easily adjust in any direction, two pins clamp connected to the external connecting rod. Our TU Multipurpose external fixator can be designed as a multiplana, can be used as a bridge or non bridge fixation, and can be adjusted to any direction which require for the treatment of distal radius fracture. It is differed to other commercially available devices. PMID:21294433

  11. Ultrasound-Guided Reduction of Distal Radius Fractures

    PubMed Central

    Sabzghabaei, Anita; Shojaee, Majid; Arhami Dolatabadi, Ali; Manouchehrifar, Mohammad; Asadi, Mahdi

    2016-01-01

    Introduction: Distal radius fractures are a common traumatic injury, particularly in the elderly population. In the present study we examined the effectiveness of ultrasound guidance in the reduction of distal radius fractures in adult patients presenting to emergency department (ED). Methods: In this prospective case control study, eligible patients were adults older than 18 years who presented to the ED with distal radius fractures. 130 consecutive patient consisted of two group of Sixty-Five patients were prospectively enrolled for around 1 years. The first group underwent ultrasound-guided reduction and the second (control group) underwent blind reduction. All procedures were performed by two trained emergency residents under supervision of senior emergency physicians. Results: Baseline characteristics between two groups were similar. The rate of repeat reduction was reduced in the ultrasound group (9.2% vs 24.6%; P = .019). The post reduction radiographic indices were similar between the two groups, although the ultrasound group had improved volar tilt (mean, 7.6° vs 3.7°; P = .000). The operative rate was reduced in the ultrasound groups (10.8% vs 27.7%; P = .014). Conclusion: Ultrasound guidance is effective and recommended for routine use in the reduction of distal radius fractures. PMID:27299141

  12. Computational Analysis of Dual Radius Circulation Control Airfoils

    NASA Technical Reports Server (NTRS)

    Lee-Rausch, E. M.; Vatsa, V. N.; Rumsey, C. L.

    2006-01-01

    The goal of the work is to use multiple codes and multiple configurations to provide an assessment of the capability of RANS solvers to predict circulation control dual radius airfoil performance and also to identify key issues associated with the computational predictions of these configurations that can result in discrepancies in the predicted solutions. Solutions were obtained for the Georgia Tech Research Institute (GTRI) dual radius circulation control airfoil and the General Aviation Circulation Control (GACC) dual radius airfoil. For the GTRI-DR airfoil, two-dimensional structured and unstructured grid computations predicted the experimental trend in sectional lift variation with blowing coefficient very well. Good code to code comparisons between the chordwise surface pressure coefficients and the solution streamtraces also indicated that the detailed flow characteristics were matched between the computations. For the GACC-DR airfoil, two-dimensional structured and unstructured grid computations predicted the sectional lift and chordwise pressure distributions accurately at the no blowing condition. However at a moderate blowing coefficient, although the code to code variation was small, the differences between the computations and experiment were significant. Computations were made to investigate the sensitivity of the sectional lift and pressure distributions to some of the experimental and computational parameters, but none of these could entirely account for the differences in the experimental and computational results. Thus, CFD may indeed be adequate as a prediction tool for dual radius CC flows, but limited and difficult to obtain two-dimensional experimental data prevents a confident assessment at this time.

  13. Finite Larmor radius flute mode theory with end loss

    SciTech Connect

    Kotelnikov, I.A.; Berk, H.L.

    1993-08-01

    The theory of flute mode stability is developed for a two-energy- component plasma partially terminated by a conducting limiter. The formalism is developed as a preliminary study of the effect of end-loss in open-ended mirror machines where large Larmor radius effects are important.

  14. Observational Constraints on the White Dwarf Mass--Radius Relation

    NASA Astrophysics Data System (ADS)

    Oswalt, Terry D.; Dhital, Saurav; Mizusawa, Trisha; Holberg, Jay B.; Zhao, Jingkun

    2014-02-01

    We propose to measure gravitational redshifts for white dwarf stars that have distant, non-interacting main-sequence companions. With independent radius constraints obtained from parallaxes and surface gravity determinations obtained by fitting the Balmer series from our spectra, we will make improved estimates of white dwarf masses and radii that can be critically compared with theoretical mass-radius relations specific to each star. These observations will allow us to examine serious discrepancies between the theoretical and empirical measurements of the white dwarf mass-radius relation and extend the range of masses over which it has been tested, spanning 0.5-1.2 Msun. Currently, the measured radius for only a single WD matches its predicted value. Using the same spectra, we will also estimate the metallicity of the main-sequence companion and examine how the initial-final-mass ratio for WDs depends on metallicity. Thus, this project will put robust constraints on two fundamental relations that govern our understanding of white dwarfs: the mass-ratio and the initial-final-mass relations.

  15. Observational Constraints on the White Dwarf Mass-Radius Relation

    NASA Astrophysics Data System (ADS)

    Dhital, Saurav; Oswalt, Terry D.; Holberg, J. B.; Zhao, Jingkun

    2014-08-01

    We propose to measure gravitational redshifts for white dwarf stars that have distant, non-interacting main-sequence companions. With independent radius constraints obtained from parallaxes and surface gravity determinations obtained by fitting the Balmer series from our spectra, we will make improved estimates of white dwarf masses and radii that can be critically compared with theoretical mass-radius relations specific to each star. These observations will allow us to examine serious discrepancies between the theoretical and empirical measurements of the white dwarf mass-radius relation and extend the range of masses over which it has been tested, spanning 0.5-1.2 Msun. Currently, the measured radius for only a single WD matches its predicted value within 5%. With the expected precision of ≲5% for over half the sample, we will also distinguish whether the white dwarfs have ``thick'' or ``thin'' H envelopes. Using the same spectra, we will also estimate the metallicity of the main-sequence companion and examine how the initial-final-mass ratio for WDs depends on metallicity. Thus, this project will put robust constraints on two fundamental relations that govern our understanding of white dwarfs: the mass-ratio and the initial-final-mass relations.

  16. Hemiarthroplasty for Complex Distal Radius Fractures in Elderly Patients

    PubMed Central

    Vergnenègre, Guillaume; Hardy, Jérémy; Mabit, Christian; Charissoux, Jean-Louis; Marcheix, Pierre-Sylvain

    2015-01-01

    Background In elderly patients, distal radius fractures frequently occur in osteoporotic bone and may be nonreconstructable. It is our hypothesis that a hemiarthroplasty replacment of the articular surface can provide satisfactory results in terms of range of motion, pain, and function for immediate salvage of a fracture that is not amenable to internal fixation. Methods Between July 2009 and January 2012, eight elderly patients were treated with insertion of a Sophia distal radius implant (Biotech, Paris, France). Inclusion criteria consisted of an isolated AO type C2 distal radius fracture in patients over 70 years old. All patients were reviewed by an independent surgeon. Results The mean follow-up was 25 months (range, 17–36 months). Mean wrist range of motion (ROM) was 45° (40–50°) of flexion, 44° (40–50°) of extension, and a mean pronation-supination arc of 160°. Mean grip force was 18 kgf. The mean QuickDASH (Disabilities of the Arm, Shoulder and Hand) was 18.2/100 (6.82–29.55), and the mean visual analog scale (VAS) was 2.33 (0–4). X-ray images did not demonstrate implant loosening or ulnar translation of the carpus. Conclusions The Sophia hemiarthroplasty provided rapid recovery of independence in elderly patients with a nonreconstructable comminuted distal radius fracture. PMID:26261741

  17. A 4-Sphere With Noncentral Radius and its Instanton Sheaf

    NASA Astrophysics Data System (ADS)

    Cirio, Lucio Simone; Pagani, Chiara

    2015-02-01

    We build an SU(2)-Hopf bundle over a quantum toric four-sphere whose radius is noncentral. The construction is carried out using local methods in terms of sheaves of Hopf-Galois extensions. The associated instanton bundle is presented and endowed with a connection with anti-self-dual curvature.

  18. Nonlinear buckling analyses of a small-radius carbon nanotube

    SciTech Connect

    Liu, Ning Li, Min; Jia, Jiao; Wang, Yong-Gang

    2014-04-21

    Carbon nanotube (CNT) was first discovered by Sumio Iijima. It has aroused extensive attentions of scholars from all over the world. Over the past two decades, we have acquired a lot of methods to synthesize carbon nanotubes and learn their many incredible mechanical properties such as experimental methods, theoretical analyses, and computer simulations. However, the studies of experiments need lots of financial, material, and labor resources. The calculations will become difficult and time-consuming, and the calculations may be even beyond the realm of possibility when the scale of simulations is large, as for computer simulations. Therefore, it is necessary for us to explore a reasonable continuum model, which can be applied into nano-scale. This paper attempts to develop a mathematical model of a small-radius carbon nanotube based on continuum theory. An Isotropic circular cross-section, Timoshenko beam model is used as a simplified mechanical model for the small-radius carbon nanotube. Theoretical part is mainly based on modified couple stress theory to obtain the numerical solutions of buckling deformation. Meanwhile, the buckling behavior of the small radius carbon nanotube is simulated by Molecular Dynamics method. By comparing with the numerical results based on modified couple stress theory, the dependence of the small-radius carbon nanotube mechanical behaviors on its elasticity constants, small-size effect, geometric nonlinearity, and shear effect is further studied, and an estimation of the small-scale parameter of a CNT (5, 5) is obtained.

  19. Effect of limiter end loss in finite Larmor radius theory

    SciTech Connect

    Berk, H.L.; Kotelnikov, I.A.

    1993-08-01

    We have examined the effect of incomplete line tying on the MHD flute mode with FLR (finite Larmor radius) effects. We show that the combination of line tying and FLR effects can slow down MHD instability, but cannot produce complete stabilization.

  20. [Differential treatment of fractures of the distal radius].

    PubMed

    Oestern, H J; Hüls, E

    1994-01-01

    Treatment of distal fractures of the radius has undergone considerable change during recent years. The cause for this lies primarily in the poor results of conservative treatments. In addition to osseous instability, the fractures of the radius are frequently combined with ligamentary instability as well, thereby exceeding the ability of conservative treatment. Among the many classifications, the AO classification of these fractures has proven to be the best and most widely accepted. This classification allows the recommendation of suitable procedures of treatment. The problem with inadequately healed fractures of the radius lies in the inherent unphysiological loading of the joint in the characteristic dorsal tilted position. This leads to a pathological displacement of the radius of flexion and extension and thereby to an overloading of the dorsal joint cartilage. The shortening of the radius leads to a mechanical impingement of the triangular fibrocartilagenous complex. The Kirschner wire fixation is particularly indicated in type A and type C fractures when combined with an external fixator. Of great importance here is the crossing of the K-wires, best accomplished by inserting an additional wire in a proximal to distal direction to achieve maximal mechanical stability. Biodegradable fixation devices are not yet in widespread use, as high costs and possible foreign body reactions have prevented their acceptance. The plate osteosynthesis has its domain in the treatment of volar luxation fractures (B3) and the partially articular fractures of the radius (B2). The domain of the external fixator, on the other hand, lies in the C2 and C3 fractures in combination with the K-wire osteosynthesis. Changing the mode of treatment to a plate osteosynthesis after two to three weeks allows a functional postoperative treatment. By use of a differentiated treatment regimen, the complication rate can be significantly reduced whose cause frequently lies in repeatedly attempted

  1. Optimal Taylor-Couette flow: radius ratio dependence

    NASA Astrophysics Data System (ADS)

    Ostilla-Mónico, Rodolfo; Huisman, Sander G.; Jannink, Tim J. G.; Van Gils, Dennis P. M.; Verzicco, Roberto; Grossmann, Siegfried; Sun, Chao; Lohse, Detlef

    2014-05-01

    Taylor-Couette flow with independently rotating inner (i) and outer (o) cylinders is explored numerically and experimentally to determine the effects of the radius ratio {\\eta} on the system response. Numerical simulations reach Reynolds numbers of up to Re_i=9.5 x 10^3 and Re_o=5x10^3, corresponding to Taylor numbers of up to Ta=10^8 for four different radius ratios {\\eta}=r_i/r_o between 0.5 and 0.909. The experiments, performed in the Twente Turbulent Taylor-Couette (T^3C) setup, reach Reynolds numbers of up to Re_i=2x10^6$ and Re_o=1.5x10^6, corresponding to Ta=5x10^{12} for {\\eta}=0.714-0.909. Effective scaling laws for the torque J^{\\omega}(Ta) are found, which for sufficiently large driving Ta are independent of the radius ratio {\\eta}. As previously reported for {\\eta}=0.714, optimum transport at a non-zero Rossby number Ro=r_i|{\\omega}_i-{\\omega}_o|/[2(r_o-r_i){\\omega}_o] is found in both experiments and numerics. Ro_opt is found to depend on the radius ratio and the driving of the system. At a driving in the range between {Ta\\sim3\\cdot10^8} and {Ta\\sim10^{10}}, Ro_opt saturates to an asymptotic {\\eta}-dependent value. Theoretical predictions for the asymptotic value of Ro_{opt} are compared to the experimental results, and found to differ notably. Furthermore, the local angular velocity profiles from experiments and numerics are compared, and a link between a flat bulk profile and optimum transport for all radius ratios is reported.

  2. OBSERVATIONAL CONSTRAINTS ON THE DEGENERATE MASS-RADIUS RELATION

    SciTech Connect

    Holberg, J. B.; Oswalt, T. D.; Barstow, M. A. E-mail: toswalt@fit.edu

    2012-03-15

    The white dwarf mass-radius relationship is fundamental to modern astrophysics. It is central to routine estimation of DA white dwarf masses derived from spectroscopic temperatures and gravities. It is also the basis for observational determinations of the white dwarf initial-final-mass relation. Nevertheless, definitive and detailed observational confirmations of the mass-radius relation (MRR) remain elusive owing to a lack of sufficiently accurate white dwarf masses and radii. Current best estimates of masses and radii allow only broad conclusions about the expected inverse relation between masses and radii in degenerate stars. In this paper, we examine a restricted set of 12 DA white dwarf binary systems for which accurate (1) trigonometric parallaxes, (2) spectroscopic effective temperatures and gravities, and (3) gravitational redshifts are available. We consider these three independent constraints on mass and radius in comparison with an appropriate evolved MRR for each star. For the best-determined systems it is found that the DA white dwarfs conform to evolve theoretical MRRs at the 1{sigma} to 2{sigma} level. For the white dwarf 40 Eri B (WD 0413-077) we find strong evidence for the existence of a 'thin' hydrogen envelope. For other stars improved parallaxes will be necessary before meaningful comparisons are possible. For several systems current parallaxes approach the precision required for the state-of-the-art mass and radius determinations that will be obtained routinely from the Gaia mission. It is demonstrated here how these anticipated results can be used to firmly constrain details of theoretical mass-radius determinations.

  3. Gyromagnetic gs factors of the spin-1/2 particles in the (1/2+-1/2--3/2-) triad of the four-vector spinor, ψμ, irreducibility and linearity

    NASA Astrophysics Data System (ADS)

    Delgado Acosta, E. G.; Banda Guzmán, V. M.; Kirchbach, M.

    2015-07-01

    The gauged Klein-Gordon equation, extended by a gsσμνFμν/4 interaction, the contraction of the electromagnetic field strength tensor, Fμν, with the generators, σμν/2, of the Lorentz group in (1/2, 0) ⊕ (0, 1/2), and gs being the gyromagnetic factor, is examined with the aim to find out as to what extent it qualifies as a wave equation for general relativistic spin-1/2 particles transforming as (1/2, 0) ⊕ (0, 1/2) and possibly distinct from the Dirac fermions. This equation can be viewed as the generalization of the gs = 2 case, known under the name of the Feynman-Gell-Mann equation, the only one which allows for a bilinearization into the gauged Dirac equation and its conjugate. At the same time, it is well-known a fact that a gs = 2 value can also be obtained upon the bilinearization of the nonrelativistic Schrödinger into nonrelativistic Pauli equations. The inevitable conclusion is that it must not be necessarily relativity which fixes the gyromagnetic factor of the electron to g(1/2) = 2, but rather the specific form of the primordial quadratic wave equation obeyed by it, that is amenable to a linearization. The fact is that space-time symmetries alone define solely the kinematic properties of the particles and neither fix the values of their interacting constants, nor do they necessarily prescribe linear Lagrangians. Information on such properties has to be obtained from additional physical inputs involving the dynamics. We here provide an example in support of the latter statement. Our case is that the spin-1/2- fermion residing within the four-vector spinor triad, ψμ (1/2+-1/2--3/2-), whose sectors at the free particle level are interconnected by spin-up and spin-down ladder operators, does not allow for a description within a linear framework at the interacting level. Upon gauging, despite transforming according to the irreducible (1/2, 1) ⊕ (1, 1/2) building block of ψμ, and being described by 16-dimensional four-vector spinors, though

  4. Variable radius cartography - History and perspectives of a new discipline

    NASA Astrophysics Data System (ADS)

    Scalera, Giancarlo

    2014-05-01

    The map that Toscanelli sent to Columbus was an unconscious application of cartography at a smaller radius than the real. The first really conscious attempts to represent the geography of Earth on globes of radius less than the current one occurred after the formulation of the concept of expanding Earth through geological time. The American chemist and geologist Richard Owen (1810-1890) in his book Key to the geology of the globe (1857) described the principles of what he himself called Anatomical Geology, with the Earth growing as a biological organism. The book contained a global paleogeographic map of the Earth that would have had a radius of about 4000 kilometers. In 1928 J.A.H. Kerkhoff (under the pseudonym Aero-dilettant) published a series of paleogeographic globes on which the modern oceans disappeared. With the same artisan methods of transfer continental outlines from a sphere to a smaller one, in 1933 O.C. Hilgenberg represented three different geological epochs, and, later, for the first time mapped paleopoles with their site-pole segments of meridian. Even today the traditional method of Hilgenberg is followed by senior researchers (Klaus Vogel, 2003) and younger geologists (James Maxlow). In England Hugh Owen applied the methods of traditional cartography to the variable radius one. His Atlas of Continental Displacement was in the 70s and 80s, for this discipline, a real milestone. While in the field of constant radius paleogeography the adherents to plate tectonics created many computer codes of automatic mapping (Bullard et al., 1965; Smith & Hallam, 1970; Scotese et al., 1979; and many others), in the variable radius field few tried to reach the same task. In 1972 in United States a first very simple attempt (but was not further developed) came from a private, R.B. Perry, followed by the still not-computerized Atlas of Owen, and both them constituted inspiration for the construction of a FORTRAN variable radius mapping code at INGV, with which it

  5. Motion perception during variable-radius swing motion in darkness.

    PubMed

    Rader, A A; Oman, C M; Merfeld, D M

    2009-10-01

    Using a variable-radius roll swing motion paradigm, we examined the influence of interaural (y-axis) and dorsoventral (z-axis) force modulation on perceived tilt and translation by measuring perception of horizontal translation, roll tilt, and distance from center of rotation (radius) at 0.45 and 0.8 Hz using standard magnitude estimation techniques (primarily verbal reports) in darkness. Results show that motion perception was significantly influenced by both y- and z-axis forces. During constant radius trials, subjects' perceptions of tilt and translation were generally almost veridical. By selectively pairing radius (1.22 and 0.38 m) and frequency (0.45 and 0.8 Hz, respectively), the y-axis acceleration could be tailored in opposition to gravity so that the combined y-axis gravitoinertial force (GIF) variation at the subject's ears was reduced to approximately 0.035 m/s(2) - in effect, the y-axis GIF was "nulled" below putative perceptual threshold levels. With y-axis force nulling, subjects overestimated their tilt angle and underestimated their horizontal translation and radius. For some y-axis nulling trials, a radial linear acceleration at twice the tilt frequency (0.25 m/s(2) at 0.9 Hz, 0.13 m/s(2) at 1.6 Hz) was simultaneously applied to reduce the z-axis force variations caused by centripetal acceleration and by changes in the z-axis component of gravity during tilt. For other trials, the phase of this radial linear acceleration was altered to double the magnitude of the z-axis force variations. z-axis force nulling further increased the perceived tilt angle and further decreased perceived horizontal translation and radius relative to the y-axis nulling trials, while z-axis force doubling had the opposite effect. Subject reports were remarkably geometrically consistent; an observer model-based analysis suggests that perception was influenced by knowledge of swing geometry. PMID:19625542

  6. Proton Radius, Darwin-Foldy Term and Radiative Corrections

    NASA Astrophysics Data System (ADS)

    Jentschura, Ulrich

    2013-04-01

    It is not an easy task to define the proton charge radius. Namely, by definition, the proton radius is the slope of the GESachs form factor of the proton at zero momentum transfer, provided one has subtracted from the scattering cross sections, all effects due to QED. That means that radiative corrections must be subtracted; these otherwise ``mask'' the proton structure from the surroundings. On the other hand, the self-energy of the proton (not of the electron or of the muon) also influence the spectrum of atomic hydrogen, or muonic hydrogen, respectively. In the talk, we shall review the difficulties faced by a consistent definition, offer a way to resolve them, and review the current status of Lamb shift predictions in muonic hydrogen, with a special reference to the current experimental-theoretical discrepancy, as reported by the CREMA collaboration.

  7. Measurements of small radius ratio turbulent Taylor-Couette flow

    NASA Astrophysics Data System (ADS)

    van der Veen, Roeland; Huisman, Sander; Merbold, Sebastian; Sun, Chao; Harlander, Uwe; Egbers, Christoph; Lohse, Detlef

    2014-11-01

    In Taylor-Couette flows, the radius ratio (η =ri /ro) is one of the key parameters of the system. For small η, the asymmetry of the inner and outer boundary layer becomes more important, affecting the general flow structure and boundary layer characteristics. Using high-resolution particle image velocimetry we measure flow profiles, local transport, and statistical properties of the flow for a radius ratio of 0.5 and a Reynolds number of up to 4 .104 . By measuring flow profiles at varying heights, roll structures are characterized for two different rotation ratios of the inner and outer cylinder. In addition, we systematically vary the rotation ratio and the Reynolds number. These results exemplify how curvature affects flow in strongly turbulent Taylor-Couette Flow.

  8. Maximal radius of the aftershock zone in earthquake networks

    NASA Astrophysics Data System (ADS)

    Mezentsev, A. Yu.; Hayakawa, M.

    2009-09-01

    In this paper, several seismoactive regions were investigated (Japan, Southern California and two tectonically distinct Japanese subregions) and structural seismic constants were estimated for each region. Using the method for seismic clustering detection proposed by Baiesi and Paczuski [M. Baiesi, M. Paczuski, Phys. Rev. E 69 (2004) 066106; M. Baiesi, M. Paczuski, Nonlin. Proc. Geophys. (2005) 1607-7946], we obtained the equation of the aftershock zone (AZ). It was shown that the consideration of a finite velocity of seismic signal leads to the natural appearance of maximal possible radius of the AZ. We obtained the equation of maximal radius of the AZ as a function of the magnitude of the main event and estimated its values for each region.

  9. Artificial gravity: head movements during short-radius centrifugation

    NASA Astrophysics Data System (ADS)

    Young, Laurence R.; Hecht, Heiko; Lyne, Lisette E.; Sienko, Kathleen H.; Cheung, Carol C.; Kavelaars, Jessica

    2001-08-01

    Short-radius centrifugation is a potential countermeasure to long-term weightlessness. Unfortunately, head movements in a rotating environment induce serious discomfort, non-compensatory vestibulo-ocular reflexes, and subjective illusions of body tilt. In two experiments we investigated the effects of pitch and yaw head movements in participants placed supine on a rotating bed with their head at the center of rotation, feel at the rim. The vast majority of participants experienced motion sickness, inappropriate vertical nystagmus and illusory tilt and roll as predicted by a semicircular canal model. However, a small but significant number of the 28 participants experienced tilt in the predicted plane but in the opposite direction. Heart rate was elevated following one-second duration head turns. Significant adaptation occurred following a series of head turns in the light. Vertical nystagmus, motion sickness and illusory tilt all decreased with adaptation. Consequences for artificial gravity produced by short-radius centrifuges as a countermeasure are discussed.

  10. Flute waves at the ion Larmor radius scales

    SciTech Connect

    Onishchenko, O. G.

    2010-12-14

    The theory of the magnetic Rayleigh-Taylor instability (RTI) is discussed. Modified linear kinetic theory allows us to investigate RTI and flute waves with arbitrary perpendicular spatial scales compared to the ion Larmor radius. It is shown that in the linear limit a Fourier transform of these equations yields the dispersion relation which in the so-called Pade approximation corresponds to results of the kinetic theory. This analysis represents an extension of the previous study of the magnetic RTI obtained in the large wave scale approximation. It is shown that incorporation of the effects associated with wave scales of the order of the ion Larmor radius leads to a broader wave number range of the magnetic RTI.

  11. [Results following percutaneous intramedullary pin fixation in distal radius fractures].

    PubMed

    Kirchner, R; Hüttl, T; Krüger-Franke, M; Rosemeyer, B

    1994-01-01

    42 distal radius fractures have been submitted to further examination after percutaneous intramedullary pin fixation. The outcome were 95.3% of very good to good anatomic results and 90.5% of satisfying functional results. This showed the close link between the radiological-anatomical and functional results. The success of the treatment was very acceptable, although the Morbus Sudeck as the major complication--with 7.2%--was still relatively frequently observed. It could be seen that particularly fractures at the risk of dislocation with smash zone constituted an indication for the percutaneous intramedullary pin fixation, that is to say all fractures for which a retention is primarily difficult. It constitutes a supplement, as well as an extension to the therapy of the distal radius fractures. PMID:7516105

  12. Reverse wedge osteotomy of the distal radius in Madelung's deformity.

    PubMed

    Mallard, F; Jeudy, J; Rabarin, F; Raimbeau, G; Fouque, P-A; Cesari, B; Bizot, P; Saint-Cast, Y

    2013-06-01

    Madelung's deformity results from a growth defect in the palmar and ulnar region of the distal radius. It presents as an excessively inclined radial joint surface, inducing "spontaneous progressive palmar subluxation of the wrist". The principle of reverse wedge osteotomy (RWO) consists in the reorientation of the radial joint surface by taking a circumferential bone wedge, the base of which is harvested from the excess of the radial and dorsal cortical bone of the distal radius, then turning it over and putting back this reverse wedge into the osteotomy so as to obtain closure on the excess and opening on the deficient cortical bone. RWO corrects the palmar subluxation of the carpus and improves distal radio-ulnar alignment. All five bilaterally operated patients were satisfied, esthetically and functionally. Its corrective power gives RWO a place apart among the surgical techniques currently available in Madelung's deformity. PMID:23622863

  13. Core Deuterium Fusion and Radius Inflation in Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Jaikumar, Prashanth; Rachid Ouyed

    2016-06-01

    Several laboratory-based studies have shown that the Deuterium fusion cross-section is enhanced in a solid deuterated target as compared to a gas target, attributable to enhanced mobility of deuterons in a metal lattice. As an application, we propose that, for core temperatures and compositions characterizing hot Jupiters, screened Deuterium fusion can occur deep in the interior, and show that the amount of radius inflation from this effect can be important if there is sufficient rock-ice in the core. The mechanism of screened Deuterium fusion, operating in the above temperature range, is generally consistent with the trend in radius anomaly with planetary equilibrium temperature. We also explore the trend with planetary mass using a simple analytic model.

  14. Thrombocytopenia with absent radius in a boy and his uncle.

    PubMed

    Schnur, R E; Eunpu, D L; Zackai, E H

    1987-09-01

    We report a boy and his maternal uncle who have Thrombocytopenia-Absent Radius (TAR) syndrome. The mother of the propositus is normal. A maternal aunt has mild radial hypoplasia, possibly representing partial expression of the syndrome. A review of the literature shows several pedigrees in which relatives other than sibs were affected with TAR. Thus, autosomal recessive inheritance may not account for all cases and alternate modes of transmission should be considered. PMID:3314504

  15. Medical management of fragility fractures of the distal radius.

    PubMed

    Morgan, Emily N; Crawford, David A; Scully, William F; Noce, Nicholas J

    2014-12-01

    Fragility fractures of the distal radius represent an opportunity to diagnose and treat osteoporosis before further fractures occur. The goal of this study was to determine the prevalence of prescriptions for calcium/vitamin D supplementation and the prevalence of dual-energy x-ray absorptiometry (DEXA) scans in patients who sustained fragility fractures of the distal radius. A further goal was to determine the prevalence of patients who received prescriptions for the treatment of osteoporosis after DEXA scans. The authors performed a retrospective review of all patients 50 years and older who sustained a fragility fracture of the distal radius and were treated by the orthopedic surgery service at the authors' institution from 2004 to 2010. After a fragility fracture of the distal radius, fewer than 25% of previously unidentified at-risk patients received a prescription for vitamin supplementation and underwent a DEXA scan. Women were 7 times more likely than men to receive calcium/vitamin D supplementation, 14 times more likely to undergo a DEXA scan for the evaluation of osteoporosis, and 25 times more likely to receive a prescription for bisphosphonates. Patients who underwent a DEXA scan were 9 times more likely to receive pharmacologic treatment than those who did not undergo this scan. More than half of patients did not receive a prescription for calcium/vitamin D supplementation and did not undergo DEXA scanning as recommended by current National Osteoporosis Foundation guidelines. Most patients who received prescriptions or underwent DEXA scans did so before rather than after fracture, indicating poor compliance with National Osteoporosis Foundation guidelines. PMID:25437080

  16. Radiographic Predictors of DRUJ Instability with Distal Radius Fractures

    PubMed Central

    Omokawa, Shohei; Iida, Akio; Fujitani, Ryotaro; Onishi, Tadanobu; Tanaka, Yasuhito

    2014-01-01

    Because the distal radioulnar joint (DRUJ) is an inherently unstable joint, the diagnosis and treatment of DRUJ instability is often difficult in a clinical hand surgery practice. Several soft tissue stabilizers are recognized, of which the deep limbs of the radioulnar ligament are primary stabilizers. This article discusses the predictors of DRUJ instability in distal radius fractures based on our clinical and biomechanical analyses. PMID:24533238

  17. Chondrosarcoma of the radius with distant metastasis in a dog.

    PubMed

    Boudrieau, R J; Schelling, S H; Pisanelli, E R

    1994-08-15

    A 9-year-old castrated male Doberman Pinscher was admitted for evaluation of lameness of the left forelimb. Radiography and examination of biopsy specimens revealed a moderately differentiated chondrosarcoma of the proximal portion of the radius. The dog was treated by local excision of the neoplasm, which involved resection of the radial head and proximal portion of the radius. Despite the large size of the dog and the weight-bearing forces exerted on the cubital joint, major problems with ambulation did not develop after surgery. Functional use of the limb returned slowly; however, substantial limb use was observed despite the development of mild degenerative changes of the joint and migration of the humeroulnar articulation. Six months after surgery, metastasis of a widely disseminated, poorly differentiated chondrosarcoma to the subcutaneous tissues and thoracic and abdominal cavities was diagnosed. Local redevelopment of the chondrosarcoma in the area of the cubital joint was not detected. Resection of the radial head and proximal portion of the radius may be considered a viable, alternative, limb-sparing technique. The biologically aggressive nature of this chondrosarcoma of the appendicular skeleton indicated that additional information was needed before a reliable prognosis could be established for this dog with this tumor type. Reports of low rates of metastasis have been based on insufficient numbers of dogs to adequately or accurately determine the long-term prognosis of dogs with chondrosarcoma of the appendicular skeleton. PMID:7961094

  18. Experimental bound on the charge radius of the electron neutrino

    SciTech Connect

    Allen, R.C.; Chen, H.H.; Doe, P.J.; Hausamann, R.; Lee, W.P.; Lu, X.; Mahler, H.J.; Potter, M.E.; Wang, K.C. ); Bowles, T.J.; Burman, R.L.; Carlini, R.D.; Cochran, D.R.F.; Frank, J.S.; Piasetzky, E.; Sandberg, V.D. ); Krakauer, D.A.; Talaga, R.L. )

    1991-01-01

    A limit on the electron-neutrino charge radius {vert bar}{ital r}{vert bar} is derived from a measurement of the weak-neutral-current vector coupling constant {ital g}{sub {ital V}} obtained in electron-neutrino electron elastic scattering. The 90%-confidence interval for {ital g}{sub {ital V}} is {minus}0.177{lt}{ital g}{sub {ital V}}{lt}0.187, which for sin{sup 2}{theta}{sub {ital W}}=0.227 implies that the {nu}{sub {ital e}} mean-square charge radius is in the range {minus}2.74{times}10{sup {minus}32}{lt}{l angle}{ital r}{sup 2}{r angle}{lt}4.88{times}10{sup {minus}32} cm{sup 2}, or simply {vert bar}{ital r}{vert bar}{lt}2.2{times}10{sup {minus}16} cm. This is the first experimental bound on the {nu}{sub {ital e}} charge radius, and is the same order of magnitude as bounds for {nu}{sub {mu}} structure.

  19. Ring polymer simulations with global radius of curvature.

    PubMed

    Neuhaus, T; Zimmermann, O; Hansmann, Ulrich H E

    2007-05-01

    We simulate three-dimensional flexible off-lattice ring polymers of length L up to L=4000 for various values of the global radius of curvature Rgrc=0.25 , 0.48, and 1.0 and Rgrc=2.0 . We utilize two different ensembles: one with a delta -function constraint on the radius, and the other with a theta -function. For both cases the global radius of curvature provides a valid regularization of polymers with thickness D=2Rgrc . The Flory-type critical exponent nu SAW of self-avoiding rings at D=2 is found to be nu SAW=0.5869(5) from the radii of gyration chain length scaling, while other D values produce consistent results. For our current implementation, the numerical effort of chain thickness calculations is bounded by a number O(LlnL) per single update. We also study low-temperature configurations of spatially dense Lennard-Jones homopolymers on a ring and identify some conformational building blocks. PMID:17677089

  20. Conversion of radius of curvature to power (and vice versa)

    NASA Astrophysics Data System (ADS)

    Wickenhagen, Sven; Endo, Kazumasa; Fuchs, Ulrike; Youngworth, Richard N.; Kiontke, Sven R.

    2015-09-01

    Manufacturing optical components relies on good measurements and specifications. One of the most precise measurements routinely required is the form accuracy. In practice, form deviation from the ideal surface is effectively low frequency errors, where the form error most often accounts for no more than a few undulations across a surface. These types of errors are measured in a variety of ways including interferometry and tactile methods like profilometry, with the latter often being employed for aspheres and general surface shapes such as freeforms. This paper provides a basis for a correct description of power and radius of curvature tolerances, including best practices and calculating the power value with respect to the radius deviation (and vice versa) of the surface form. A consistent definition of the sagitta is presented, along with different cases in manufacturing that are of interest to fabricators and designers. The results make clear how the definitions and results should be documented, for all measurement setups. Relationships between power and radius of curvature are shown that allow specifying the preferred metric based on final accuracy and measurement method. Results shown include all necessary equations for conversion to give optical designers and manufacturers a consistent and robust basis for decision-making. The paper also gives guidance on preferred methods for different scenarios for surface types, accuracy required, and metrology methods employed.

  1. Plate presetting arthroscopic reduction technique for the distal radius fractures.

    PubMed

    Abe, Yukio; Tsubone, Tetsu; Tominaga, Yasuhiro

    2008-09-01

    Wrist arthroscopy for the distal radius fractures is an effective adjunct to evaluate the reduction of intraarticular fragments and soft tissue injuries. In recent years, volar locking plate fixation has become popular, and arthroscopic procedures for distal radius fracture reduction have become problematic because vertical traction has to be both on and off during surgery. We developed a plate presetting arthroscopic reduction technique to simplify the combination of plating and arthroscopy. The fracture was reduced, and anatomic alignment was regained under an image intensifier, and then the volar locking plate was preset. Wrist arthroscopy was introduced under vertical traction, and the intraarticular condition was assessed. If dislocations of the intraarticular fragments were residual, they were reduced arthroscopically, and soft tissue injuries were treated subsequently. Finally, the traction was removed, and the plate was securely fixed. Since May 2005, the authors have used this technique in more than 50 patients. This article will review the history, indications, contraindications, technique, rehabilitation, and complications for the plate presetting arthroscopic reduction technique for distal radius fractures. PMID:18776773

  2. Stokes radius determination of radioiodinated polypeptide hormones by gel filtration

    SciTech Connect

    Ribela, M.T.; Bartolini, P.

    1988-11-01

    A simple technique for determination of the molecular (Stokes) radius of radioiodinated proteins was developed using the same column and chromatographic conditions employed in routine radioimmunoassay tracer purification. The calibration curve for five radioiodinated standard proteins presented a highly significant correlation (r = -0.996; P less than 0.001) and allowed precise molecular radius determination for labeled human growth hormone (hGH), luteotropin (hLH), follicle-stimulating hormone (hFSH), thyrotropin (hTSH), prolactin (hPRL), and corticotropin (hACTH), enabling detection of differences of the order of +/- 3%. The validity of the method was verified by determining the molecular radius of hGH in both ''cold'' (unlabeled standards and unknowns) and ''hot'' (radioiodinated standards and unknowns) systems. The technique can be applied in a very simple manner, requiring just one simple additional calibration run before Sephadex G-100 tracer purification. Furthermore, it can be applied to any protein, even when only extremely limited amounts are available. Since the standards and unknowns are labeled and chromatographed under identical conditions, potential common alterations of the molecule due to oxidation, iodine incorporation, tracer-carrier interactions, etc., are automatically corrected for.

  3. Is the proton radius puzzle evidence of extra dimensions?

    NASA Astrophysics Data System (ADS)

    Dahia, F.; Lemos, A. S.

    2016-08-01

    The proton charge radius inferred from muonic hydrogen spectroscopy is not compatible with the previous value given by CODATA-2010, which, on its turn, essentially relies on measurements of the electron-proton interaction. The proton's new size was extracted from the 2S-2P Lamb shift in the muonic hydrogen, which showed an energy excess of 0.3 meV in comparison to the theoretical prediction, evaluated with the CODATA radius. Higher-dimensional gravity is a candidate to explain this discrepancy, since the muon-proton gravitational interaction is stronger than the electron-proton interaction and, in the context of braneworld models, the gravitational potential can be hugely amplified in short distances when compared to the Newtonian potential. Motivated by these ideas, we study a muonic hydrogen confined in a thick brane. We show that the muon-proton gravitational interaction modified by extra dimensions can provide the additional separation of 0.3 meV between the 2S and 2P states. In this scenario, the gravitational energy depends on the higher-dimensional Planck mass and indirectly on the brane thickness. Studying the behavior of the gravitational energy with respect to the brane thickness in a realistic range, we find constraints for the fundamental Planck mass that solve the proton radius puzzle and are consistent with previous experimental bounds.

  4. Neutron charge radius and the neutron electric form factor

    SciTech Connect

    Gentile, T. R.; Crawford, C. B.

    2011-05-15

    For nearly forty years, the Galster parametrization has been employed to fit existing data for the neutron electric form factor, G{sub E}{sup n}, vs the square of the four-momentum transfer, Q{sup 2}. Typically this parametrization is constrained to be consistent with experimental data for the neutron charge radius. However, we find that the Galster form does not have sufficient freedom to accommodate reasonable values of the radius without constraining or compromising the fit. In addition, the G{sub E}{sup n} data are now at sufficient precision to motivate a two-parameter fit (or three parameters if we include thermal neutron data). Here we present a modified form of a two-dipole parametrization that allows this freedom and fits both G{sub E}{sup n} (including recent data at both low and high four-momentum transfer) and the charge radius well with simple, well-defined parameters. Analysis reveals that the Galster form is essentially a two-parameter approximation to the two-dipole form but becomes degenerate if we try to extend it naturally to three parameters.

  5. Infected Nonunion of Radius and Ulna – Strategy of Approach

    PubMed Central

    Parihar, Mangal; Ahuja, Divya

    2012-01-01

    Introduction: Infected nonunion of radius and ulna are rare but difficult problems to deal. We report a case of successfully managed infected non-unonion of forearm bones and the reasoning behind strategy of approach to the case. Case Report: 42 year old female presented with history of closed forearm fracture three months back for which she was operated with open reduction and internal fixation using dynamic compression plate. There was pain and fever post-surgery and discharge and wound gape. This was treated with resuturing of the wound and oral antibiotics. She continued to have pain fever and discharge and consulted another surgeon who removed first the radius plate and then the ulna plate sequentially with stabilisation by external fixation. She presented to us at three months post injury with infected nonunion of radius and ulna with loosening of fixators, sequestrum on radiograph and wristdrop. A staged treatment was planned for her. As first stage debridement, antibiotic Calcium Sulphate cement bead insertion and intramedullary flexible nail fixation. She was given iv antibiotics as per culture report. At 3 months post surgery the infection had settled and pellets were resorbed. Double barrel vascularized fibula graft was used to fill the gap and fixation using long locked plates was done. At one year follow up radiographs showed good healing and clinically patient had a good elbow movements and was able to carry out her daily activities. Conclusions: Proper planning and staged management of such cases helps to achieve goals with good functional outcome.

  6. Volar, Intramedullary, and Percutaneous Fixation of Distal Radius Fractures.

    PubMed

    Alluri, Ram; Longacre, Matthew; Pannell, William; Stevanovic, Milan; Ghiassi, Alidad

    2015-11-01

    Background The management of extra-articular distal radius fractures is highly variable, with no clear consensus regarding their optimal management. Purpose To assess comparatively the biomechanical stability of Kirschner wire (K-wire) fixation, volar plating, and intramedullary nailing for unstable, extra-articular distal radius fractures with both (1) constant and (2) cyclical axial compression, simulating forces experienced during early postoperative rehabilitation. Methods Twenty-six volar locking plate, intramedullary nail, and K-wire bone-implant constructs were biomechanically assessed using an unstable extra-articular distal radius bone model. Bone implant models were created for each type of construct. Three samples from each construct underwent compressive axial loading until fixation failure. The remaining samples from each construct underwent fatigue testing with a 50-N force for 2,000 cycles followed by repeat compressive axial loading until fixation failure. Results Axial loading revealed the volar plate was significantly stiffer than the intramedullary nail and K-wire constructs. Both the volar plate and intramedullary nail required greater than 300 N of force for fixation failure, while the K-wire construct failed at less than 150 N. Both the volar plate and intramedullary nail demonstrated less than 1 mm of displacement during cyclic loading, while the K-wire construct displaced greater than 3 mm. Postfatigue testing demonstrated the volar plate was stiffer than the intramedullary nail and K-wire constructs, and both the volar plate and intramedullary nail required greater than 300 N of force for fixation failure while the K-wire construct failed at less than 150 N. Conclusions Volar plating of unstable extra-articular distal radius fractures is biomechanically stiffer than K-wire and intramedullary fixation. Both the volar plate and intramedullary nail demonstrated the necessary stability and stiffness to maintain anatomic

  7. Maximum wind radius estimated by the 50 kt radius: improvement of storm surge forecasting over the Western North Pacific

    NASA Astrophysics Data System (ADS)

    Takagi, H.; Wu, W.

    2015-10-01

    Even though the maximum wind radius (Rmax) is an important parameter in determining the intensity and size of tropical cyclones, it has been overlooked in previous storm surge studies. This research reviewed the existing estimation methods of Rmax based on the central pressure or maximum wind speed. These over or underestimated Rmax because of the substantial variety of the data, though an average radius could be moderately estimated. Alternatively, we proposed an Rmax estimation method based on the radius of the 50 knot wind (R50). The data obtained during the passage of strong typhoons by a meteorological station network in the Japanese archipelago enabled us to derive the following formula, Rmax = 0.23R50. Although this new method substantially improved the estimation of Rmax compared to the existing models, an estimation error was unavoidable because of fundamental uncertainties regarding the typhoon's structure or insufficient number of available typhoon data. In fact, a numerical simulation from 2013 Typhoon Haiyan demonstrated a substantial difference in the storm surge height for different Rmax. Therefore, the variability of Rmax should be taken into account in storm surge simulations, independently of the model used, to minimize the risk of over or underestimation of storm surges. The proposed method is expected to increase the reliability of storm surge prediction and contribute to disaster risk management, particularly in the Western North Pacific, including countries such as Japan, China, Taiwan, Philippines, and Vietnam.

  8. HABITABILITY OF EXOMOONS AT THE HILL OR TIDAL LOCKING RADIUS

    SciTech Connect

    Hinkel, Natalie R.; Kane, Stephen R.

    2013-09-01

    Moons orbiting extrasolar planets are the next class of object to be observed and characterized for possible habitability. Like the host-planets to their host-star, exomoons have a limiting radius at which they may be gravitationally bound, or the Hill radius. In addition, they also have a distance at which they will become tidally locked and therefore in synchronous rotation with the planet. We have examined the flux phase profile of a simulated, hypothetical moon orbiting at a distant radius around the confirmed exoplanets {mu} Ara b, HD 28185 b, BD +14 4559 b, and HD 73534 b. The irradiated flux on a moon at its furthest, stable distance from the planet achieves its largest flux gradient, which places a limit on the flux ranges expected for subsequent (observed) moons closer in orbit to the planet. We have also analyzed the effect of planetary eccentricity on the flux on the moon, examining planets that traverse the habitable zone either fully or partially during their orbit. Looking solely at the stellar contributions, we find that moons around planets that are totally within the habitable zone experience thermal equilibrium temperatures above the runaway greenhouse limit, requiring a small heat redistribution efficiency. In contrast, exomoons orbiting planets that only spend a fraction of their time within the habitable zone require a heat redistribution efficiency near 100% in order to achieve temperatures suitable for habitability. This means that a planet does not need to spend its entire orbit within the habitable zone in order for the exomoon to be habitable. Because the applied systems comprise giant planets around bright stars, we believe that the transit detection method is most likely to yield an exomoon discovery.

  9. [Radius fractures in children--causes and mechanisms of injury].

    PubMed

    Antabak, Anko; Stanić, Lana; Matković, Nikša; Papeš, Dino; Romić, Ivan; Fuchs, Nino; Luetić, Tomislav

    2015-01-01

    Radius fractures are the most common fractures in childhood. The main mechanism of injury is fall onto an outstretched hand. This retrospective study analyzed the data on 201 children admitted for radius fractures at KBC-Zagreb in the period 2011-2013. The study included 85 girls (42.3%) and 116 boys (57.7%) . The average age of the children was 9.6 years. Radius was injured in the distal segment in 79.1% of children. The sites of injuries were: park, campi and beach (24.9% of all children), playground, skate park and swimming pool (23.9%), kindergarten or school (20.9%), at home and around the house (17.9%), in the street (11.4%) and in the store or at a hotel (0.9%). The boys were mostly injured at playgrounds, during skating and at swimming pools (37.1% of all boys), while girls were mostly injured in parks, camps and at beach (42.4% girls). Fall was the major cause of the injury (49.3%), and children usually fell during ice skating and skating (32.3% of all falls). In 20.4% the injury was caused by pushing and hitting. The smallest percentage (9.5%) of children were injured in traffic accidents while riding a bike (only one child was hit by a car). Sport related activities caused injuries in 53.7% of the cases. Sport activities are the most important cause of the radial fractures in the pediatric population and falls during sports are the main mechanism of injury. The peak incidence is at 12 years for boys and at 10 years for girls, so intervention and/or prevention should be aimed at the age groups. Preventive actions should be focused on injuries that tend to occur in parks, schools and during sport activities. PMID:26065283

  10. Radiographic Outcomes of Volar Locked Plating for Distal Radius Fractures

    PubMed Central

    Mignemi, Megan E.; Byram, Ian R.; Wolfe, Carmen C.; Fan, Kang-Hsien; Koehler, Elizabeth A.; Block, John J.; Jordanov, Martin I.; Watson, Jeffry T.; Weikert, Douglas R.; Lee, Donald H.

    2013-01-01

    Purpose To assess the ability of volar locked plating to achieve and maintain normal radiographic parameters for articular stepoff, volar tilt, radial inclination, ulnar variance, and radial height in distal radius fractures. Methods We performed a retrospective review of 185 distal radius fractures that underwent volar locked plating with a single plate design over a 5-year period. We reviewed radiographs and recorded measurements for volar tilt, radial inclination, ulnar variance, radial height, and articular stepoff. We used logistic regression to determine the association between return to radiographic standard norms and fracture type. Results At the first and final postoperative follow-up visits, we observed articular congruence less than 2 mm in 92% of fractures at both times. Normal volar tilt (11°) was restored in 46% at the first follow-up and 48% at the final one. Radial inclination (22°) was achieved in 44% at the first follow-up and 43% at the final one, and ulnar variance (01 ± 2 mm) was achieved in 53% at the first follow-up and 53% at the final one. In addition, radial height (14 ± 1mm) was restored in 14% at the first follow-up and 12% at the final one. More complex, intra-articular fractures (AO class B and C and Frykman types 3, 4, 7, and 8) were less likely to be restored to normal radiographic parameters. However, because of the small sample size for some fracture types, it was difficult to discover significant associations between fracture type and radiographic outcome. Conclusions Volar locked plating for distal radius fractures achieved articular stepoff less than 2 mm in most fractures but only restored and maintained normal radiographic measurements for volar tilt, radial inclination, and ulnar variance in 50% of fractures. The ability of volar locked plating to restore and maintain ulnar variance and volar tilt decreased with more complex intra-articular fracture types. PMID:23218558

  11. Measurement of Capillary Radius and Contact Angle within Porous Media.

    PubMed

    Ravi, Saitej; Dharmarajan, Ramanathan; Moghaddam, Saeed

    2015-12-01

    The pore radius (i.e., capillary radius) and contact angle determine the capillary pressure generated in a porous medium. The most common method to determine these two parameters is through measurement of the capillary pressure generated by a reference liquid (i.e., a liquid with near-zero contact angle) and a test liquid. The rate of rise technique, commonly used to determine the capillary pressure, results in significant uncertainties. In this study, we utilize a recently developed technique for independently measuring the capillary pressure and permeability to determine the equivalent minimum capillary radii and contact angle of water within micropillar wick structures. In this method, the experimentally measured dryout threshold of a wick structure at different wicking lengths is fit to Darcy's law to extract the maximum capillary pressure generated by the test liquid. The equivalent minimum capillary radii of different wick geometries are determined by measuring the maximum capillary pressures generated using n-hexane as the working fluid. It is found that the equivalent minimum capillary radius is dependent on the diameter of pillars and the spacing between pillars. The equivalent capillary radii of micropillar wicks determined using the new method are found to be up to 7 times greater than the current geometry-based first-order estimates. The contact angle subtended by water at the walls of the micropillars is determined by measuring the capillary pressure generated by water within the arrays and the measured capillary radii for the different geometries. This mean contact angle of water is determined to be 54.7°. PMID:26538412

  12. Ground solar radius survey in view of microsatellite missions

    NASA Astrophysics Data System (ADS)

    Delmas, C.; Morand, F.; Laclare, F.; Irbah, A.; Thuillier, G.; Bourget, P.

    For the last 25 years, ground time series of the solar radius have shown (different) apparent variations according to different instruments. The origin of these variations may search in the observer, the instrument, the atmosphere and up to the sun. Ground instruments are automated to reduce the “personnal equation” and place that origin in the atmosphere and/or in the sun. Astrometric satellites scheduled at the end of this decade will perform non ambiguous diameter measurements. A survey of the Solar radius has been initiated in 1975 by Francis Laclare, at the Calern site of the Observatoire de la Côte d’Azur, which have been chosen for hosting the ground segment of the Centre National d’Etudes Spatiales (CNES) Microsatellite PICARD mission, to be launched in 2008. This reference series was obtained by Visual observations of the Sun, with a Solar Astrolabe whose metrological character has to be stressed. Considering the Visual series results, we have compared the solar diameter variations with the solar activity cycle, and we found an opposite phase, for the whole series and at the different times of the cycles. Parallel to that series, CCD measurements were made with the same instrument and gave results which are perfectly blended together, within our quoted uncertainties. Located next to the Solar Astrolabe, DORAYSOL (Définition et Observation du Rayon Solaire) is a second generation instrument, which keeps the major features of the design of its predecessor and, which is designed to increase the number of CCD measurements and to be eventually automated. Since 1999, both series overlap correctly within our quoted uncertainties. Some information is added to explain the pattern of the PICARD mission ground segment, next to those instruments at Calern Observatory, as well as the international network intended to carry out the Sun’s Radius ground survey (R2S3: Réseau de Suivi au Sol du Rayon Solaire).

  13. Trajectory Calculator for Finite-Radius Cutter on a Lathe

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy; Strekalov, Dmitry; Yu, Nan

    2009-01-01

    A computer program calculates the two-dimensional trajectory (radial vs. axial position) of a finite-radius-of-curvature cutting tool on a lathe so as to cut a workpiece to a piecewise-continuous, analytically defined surface of revolution. (In the original intended application, the tool is a diamond cutter, and the workpiece is made of a crystalline material and is to be formed into an optical resonator disk.) The program also calculates an optimum cutting speed as F/L, where F is a material-dependent empirical factor and L is the effective instantaneous length of the cutting edge.

  14. Concentration at a radius for Hardy class functions

    NASA Astrophysics Data System (ADS)

    Kelly, Brian P.

    2007-03-01

    In this paper we establish the fundamental properties of concentration at a radius for functions in the classical Hardy space on the unit disk. For f(z) which is not identically zero and given r, 0

  15. Management of Intercarpal Ligament Injuries Associated with Distal Radius Fractures.

    PubMed

    Desai, Mihir J; Kamal, Robin N; Richard, Marc J

    2015-08-01

    The prevalence of ligamentous injury associated with fractures of the distal radius is reported to be as high as 69% with injury to the scapholunate interosseous ligament and lunotriquetral interosseous ligament occurring in 16% to 40% and 8.5% to 15%, respectively. There is a lack of consensus on which patients should undergo advanced imaging, arthroscopy, and treatment and whether this changes their natural history. Overall, patients with high-grade intercarpal ligament injuries are shown to have longer-term disability and sequelae compared with those with lower-grade injuries. This article reviews the diagnosis and treatment options for these injuries. PMID:26205702

  16. Radius of gyration and intrinsic viscosity of polyelectrolyte solutions

    SciTech Connect

    Milas, M.; Borsali, R.; Rinaudo, M.

    1993-12-31

    Relatively low molecular weights polyelectrolytes (10{sup 4}-10{sup 6}) behave as worm-like chain when electrostatic repulsions are assumed to govern the excluded volume parameter. Under such conditions, predictions of chain expansion and effect of polyelectrolyte concentrations are made assuming that unperturbed dimensions could be obtained at infinite salt content. Experimental studies of an ionic polysaccharide, namely the Na-hyaluronate, were done and the values obtained for the radius of gyration as well as the intrinsic viscosity at different charge densities are in good agreement with the predictions.

  17. Method and apparatus for logging short radius horizontal drainholes

    SciTech Connect

    Taylor, D.E.

    1991-04-30

    This patent describes an apparatus for use in logging a short radius horizontal drainhole. It comprises: a tubing string having a low portion; the lower portion of the tubing string including sensor support means therein; the lower portion of the tubing string containing openings communicating with the interior thereof in the vicinity of the sensor support means to thereby exposed the interior to the pressure and temperature conditions of the horizontal drainhole; and the lower portion of the tubing string including an end portion extending transversely of the tubing sting.

  18. Progress towards a measurement of the proton radius in hydrogen

    NASA Astrophysics Data System (ADS)

    Vutha, A. C.; Bezginov, N.; Ferchichi, I.; George, M. C.; Weel, M.; Storry, C. H.; Hessels, E. A.

    2014-05-01

    The proton's charge radius continues to have a 7 standard-deviation discrepancy between its CODATA value and determinations from muonic hydrogen measurements. Improved measurements in atomic hydrogen will shed light on this discrepancy. We present a novel experimental scheme, using frequency-offset separated oscillatory fields in standing-wave waveguides, to measure the n=2 Lamb shift in a fast metastable hydrogen beam. We report on our progress, including our first observations of microwave transitions in a fast metastable beam and high signal-to-noise ratio detection in a large-solid-angle photoionization detector. We acknowledge funding from NSERC, CFI, CRC, ORF, and NIST.

  19. Artificial gravity: head movements during short-radius centrifugation

    NASA Technical Reports Server (NTRS)

    Young, L. R.; Hecht, H.; Lyne, L. E.; Sienko, K. H.; Cheung, C. C.; Kavelaars, J.

    2001-01-01

    Short-radius centrifugation is a potential countermeasure to long-term weightlessness. Unfortunately, head movements in a rotating environment induce serious discomfort, non-compensatory vestibulo-ocular reflexes, and subjective illusions of body tilt. In two experiments we investigated the effects of pitch and yaw head movements in participants placed supine on a rotating bed with their head at the center of rotation, feet at the rim. The vast majority of participants experienced motion sickness, inappropriate vertical nystagmus and illusory tilt and roll as predicted by a semicircular canal model. However, a small but significant number of the 28 participants experienced tilt in the predicted plane but in the opposite direction. Heart rate was elevated following one-second duration head turns. Significant adaptation occurred following a series of head turns in the light. Vertical nystagmus, motion sickness and illusory tilt all decreased with adaptation. Consequences for artificial gravity produced by short-radius centrifuges as a countermeasure are discussed. Grant numbers: NCC 9-58. c 2001. Elsevier Science Ltd. All rights reserved.

  20. Corrective osteotomies of the radius: Grafting or not?

    PubMed Central

    Mugnai, Raffaele; Tarallo, Luigi; Lancellotti, Enrico; Zambianchi, Francesco; Di Giovine, Ettore; Catani, Fabio; Adani, Roberto

    2016-01-01

    AIM: To review the current literature regarding corrective osteotomies to provide the best evidence of the rule of bone grafting. METHODS: Our MEDLINE literature search included 280 studies using the following key words “Malunited distal radius fracture” and 150 studies using key words “Corrective osteotomy of the distal radius”. Inclusion criteria were: Malunited distal radial, extra articular fracture, volar locking plate, use of iliac bone graft (cancellous or corticocancellous), non-use of bone graft. Twelve studies met the inclusion criteria. RESULTS: Seven of the 12 studies considered, described the use of a graft; the remaining five studies didn’t use any graft. Type of malunion was dorsal in most of the studies. The healing time was comparable using the graft or not (mean 12.5 wk), ranging from 7.5 to 16 wk. The mean disabilities of the arm, shoulder and hand score improvement was 23 points both in the studies that used the graft and in those not using the graft. CONCLUSION: This review demonstrated that corrective osteotomy of extra-articular malunited fractures of the distal radius treated by volar locking plate does not necessarily require bone graft. PMID:26925385

  1. Pion loop contribution to the electromagnetic pion charge radius

    SciTech Connect

    Roberts, C.D.; Bender, A.; Alkofer, R.

    1995-08-01

    There is a widely held misconception, based on a misrepresentation of the application of chiral perturbation theory, that the electromagnetic structure of the pion is dominated by the pion`s own pion-cloud. To clarify this the Global Color-symmetry Model (GCM), was used to calculate the electromagnetic charge radius of the pion. In this calculation the contributions from the quark core and pion loop were identified and compared. It was shown explicitly that the divergence of the charge radius in the chiral limit is due solely to the pion loop and that, at the physical value of the pion mass, this loop contributes less than 15% {l_angle}r{sub {pi}}{sup 2}{r_angle}; i.e. the quark core is the dominant determining characteristic for the pion. This suggests that quark-based models that fail to reproduce the m{sub {pi}} divergence of {l_angle}{sub {pi}}{sup 2}{r_angle} nevertheless incorporate the dominant characteristic of the pion: its quark core. The result`s studylend further support to the contention that, away from resonances, the dominant determining characteristic of kinematic and dynamical properties of hadrons is their quark core. A paper describing this work was submitted for publication.

  2. Automated bone age assessment of older children using the radius

    NASA Astrophysics Data System (ADS)

    Tsao, Sinchai; Gertych, Arkadiusz; Zhang, Aifeng; Liu, Brent J.; Huang, Han K.

    2008-03-01

    The Digital Hand Atlas in Assessment of Skeletal Development is a large-scale Computer Aided Diagnosis (CAD) project for automating the process of grading Skeletal Development of children from 0-18 years of age. It includes a complete collection of 1,400 normal hand X-rays of children between the ages of 0-18 years of age. Bone Age Assessment is used as an index of skeletal development for detection of growth pathologies that can be related to endocrine, malnutrition and other disease types. Previous work at the Image Processing and Informatics Lab (IPILab) allowed the bone age CAD algorithm to accurately assess bone age of children from 1 to 16 (male) or 14 (female) years of age using the Phalanges as well as the Carpal Bones. At the older ages (16(male) or 14(female) -19 years of age) the Phalanges as well as the Carpal Bones are fully developed and do not provide well-defined features for accurate bone age assessment. Therefore integration of the Radius Bone as a region of interest (ROI) is greatly needed and will significantly improve the ability to accurately assess the bone age of older children. Preliminary studies show that an integrated Bone Age CAD that utilizes the Phalanges, Carpal Bones and Radius forms a robust method for automatic bone age assessment throughout the entire age range (1-19 years of age).

  3. A variable-radius measure of local hospital market structure.

    PubMed Central

    Phibbs, C S; Robinson, J C

    1993-01-01

    OBJECTIVE. To provide a radius measure of the structure of local hospital markets that varies with hospital characteristics and is available for all hospitals in the United States. DATA SOURCES. 1982 American Hospital Association (AHA) Survey of Hospitals, 1982 Area Resource File (ARF), and 1983 California Office of Statewide Health Planning and Development (OSHPD) discharge abstracts. STUDY DESIGN. The OSHPD data were used to measure the radii necessary to capture 75 percent and 90 percent of each hospital's admissions. These radii were used as the dependent variables in regression models in which the independent variables were from the AHA and ARF. To estimate predicted market radii, the estimated parameters from the California models were applied to all nonfederal, short-term, general hospitals in the continental United States. These radii were used to define each hospital's service area, and all other hospitals within the calculated radii were considered potential competitors. Using this definition, we calculated two measures of local market structure: the number of other hospitals within the radius and a Herfindahl-Hirschman Index based on the distribution of hospital bed shares in the market. DATA EXTRACTION METHODS. These measures were calculated for all nonfederal, short-term, acute care hospitals in the continental United States for whom complete data were available (N = 4,884). CONCLUSIONS. These measures are available from the authors on computer-readable diskette, matched to hospital identifiers. PMID:8344822

  4. Normal Age-Related Alterations on Distal Radius Radiography

    PubMed Central

    Namazi, Hamid; Khaje, Rohallah

    2015-01-01

    Background: The present study was designed to ascertain serial changes on distal radius radiographic parameters attributable to aging. Methods: In this prospective study, the sample consisted of 120 healthy individuals who were divided into four age groups each containing 15 males and 15 females. In the two below-20-year-old groups, only ulnar variance could be investigated. Wrist radiography was taken and then parameters of the distal radius were measured and compared based on age and sex. Results: Average UV was -2.48 mm and -1.6 mm in the 2-9 and 10-19-year-old age groups, respectively. Also, in the two above-20-year-old groups, the average radial inclination (RI), palmar tilt (PT), radial length (RL), and UV was 23.7º, 12.4º, 10.5 and +1.1 mm, respectively. Considering ulnar variance, no significant difference was found between the 2-9- and 10-19-year-old groups, as well as among the two above-20-year-old groups. However, a significant difference was observed between the below 20 and above 20 groups. The study results showed no significant differences between males and females in any of the study groups. Discussion: There is significant ulnar variance change toward less negative ulnar variance with aging until maturity. PMID:26550588

  5. The energy-weighted sum rule and the nuclear radius

    NASA Astrophysics Data System (ADS)

    Schröder, Hans Peter

    2015-09-01

    The energy-weighted integrated cross-section for photon absorption --known as sum rule -- is under certain conditions proportional to the mean square nuclear radius (Levinger, Bethe (Phys. Rev. 78, 115 (1950))). Due to the energy weight factor the low-energy absorption components are emphasized and the dipole transitions in the region of giant resonances contribute enhanced at . Thus, the cross-section of the full interaction can be replaced in good approximation by the dipole cross-section. Under these aspects, we have calculated and the radii of various gg-nuclei. For our purpose, we have chosen a simple shell model where the integrals can be solved analytically, and the contributions of uncorrelated functions and correlation corrections can be shown explicitly. The mean square radius as a function of differs by a factor of 1.5/0.87 from the previous result of Levinger and Kent (Phys. Rev. 95, 418 (1954)) without correlation corrections. Plotting the function of the correlation corrections and the uncorrelated function as a ratio it shows that tends towards a limit. Finally, our results for the radii of gg-nuclei are in good agreement with recent experiments (I. Angeli, K.P. Marinova, At. Data Nucl. Data Tables 99, 69 (2013)).

  6. Finite Larmor radius effect on ion pickup at Venus

    NASA Technical Reports Server (NTRS)

    Phillips, J. L.; Luhmann, J. G.; Russell, C. T.; Moore, K. R.

    1987-01-01

    The interaction of the solar wind with Venus is influenced by the pickup of newly born exospheric oxygen ions by the convecting magnetosheath plasma. The flow and field configuration of the magnetosheath plasma, together with the large gyroradius of the pickup ions, cause mass loading to occur preferentially on one side of the magnetosheath. The observed hemispherical asymmetry in the magnetic field in the near-planet magnetosheath, attributed to this pickup process, is confirmed by direct observation of the picked-up planetary particles. Test particle calculations show that a current system created by ion pickup has the appropriate location and magnitude to account for the magnetic field asymmetry. The results indicate that a fluid treatment of the Venus mass-loading problem is not entirely appropriate; a hybrid or kinetic model is necessary to incorporate the finite Larmor radius of the pickup particles which produces the observed asymmetry.

  7. Severely comminuted radius fracture presenting as a signature patterned injury

    PubMed Central

    Jain, Saurabh; Rajan, Sunil; Srivastava, Abhishek

    2016-01-01

    Dilemma still prevails, regarding the exact management of mangled extremity injuries between limb salvage versus amputation, each having there own set of complications. We here present a case of severely comminuted fractures of radius (bag of bones) along with the multiple criss-cross shaped lacerated wounds on the forearm and wrist presenting as a “signature pattern injury” caused by entrapment of the limb in the concrete mixer. MESS score of patient was 8, a score valid for amputation, but contrary, we successfully salvaged the patient's limb with use of radio-carpal distracter. Management of mangled injuries should be individualized, with due consideration to the mechanism and force of injury, associated injuries, and the patient profile. PMID:27053813

  8. Inductive voltage adder (IVA) for submillimeter radius electron beam

    SciTech Connect

    Mazarakis, M.G.; Poukey, J.W.; Maenchen, J.E.

    1996-12-31

    The authors have already demonstrated the utility of inductive voltage adder accelerators for production of small-size electron beams. In this approach, the inductive voltage adder drives a magnetically immersed foilless diode to produce high-energy (10--20 MeV), high-brightness pencil electron beams. This concept was first demonstrated with the successful experiments which converted the linear induction accelerator RADLAC II into an IVA fitted with a small 1-cm radius cathode magnetically immersed foilless diode (RADLAC II/SMILE). They present here first validations of extending this idea to mm-scale electron beams using the SABRE and HERMES-III inductive voltage adders as test beds. The SABRE experiments are already completed and have produced 30-kA, 9-MeV electron beams with envelope diameter of 1.5-mm FWHM. The HERMES-III experiments are currently underway.

  9. Radius of the ρ meson determined from its decay constant

    NASA Astrophysics Data System (ADS)

    Krutov, A. F.; Polezhaev, R. G.; Troitsky, V. E.

    2016-02-01

    We present a unified model describing electroweak properties of the π and ρ mesons. Using a general method of the relativistic parametrization of matrix elements of local operators, adjusted for the nondiagonal in the total angular momentum case, we calculate the ρ -meson lepton-decay constant fρ using the same parameters of free constituent quarks that have ensured exclusively good results for the π meson previously. The only free parameter, characterizing quark interactions, which include an additional spin-spin contribution and hence differ from the π -meson case, is fixed by matching the decay constant to its experimental value. The mean square charge radius is calculated, ⟨rρ2⟩=(0.56 ±0.04 ) fm2 . This result confirms, for the ρ -meson case, the conjecture of equality between electromagnetic and strong radii of hadrons. This conjecture was tested previously for proton, π and K mesons.

  10. Muonic bound systems, virtual particles, and proton radius

    NASA Astrophysics Data System (ADS)

    Jentschura, U. D.

    2015-07-01

    The proton radius puzzle questions the self-consistency of theory and experiment in light muonic and electronic bound systems. Here we summarize the current status of virtual particle models as well as Lorentz-violating models that have been proposed in order to explain the discrepancy. Highly charged one-electron ions and muonic bound systems have been used as probes of the strongest electromagnetic fields achievable in the laboratory. The average electric field seen by a muon orbiting a proton is comparable to hydrogenlike uranium and, notably, larger than the electric field in the most advanced strong-laser facilities. Effective interactions due to virtual annihilation inside the proton (lepton pairs) and process-dependent corrections (nonresonant effects) are discussed as possible explanations of the proton size puzzle. The need for more experimental data on related transitions is emphasized.

  11. Hydrodynamic radius fluctuations in model DNA-grafted nanoparticles

    NASA Astrophysics Data System (ADS)

    Vargas-Lara, Fernando; Starr, Francis W.; Douglas, Jack F.

    2016-05-01

    We utilize molecular dynamics simulations (MD) and the path-integration program ZENO to quantify hydrodynamic radius (Rh) fluctuations of spherical symmetric gold nanoparticles (NPs) decorated with single-stranded DNA chains (ssDNA). These results are relevant to understanding fluctuation-induced interactions among these NPs and macromolecules such as proteins. In particular, we explore the effect of varying the ssDNA-grafted NPs structural parameters, such as the chain length (L), chain persistence length (lp), NP core size (R), and the number of chains (N) attached to the nanoparticle core. We determine Rh fluctuations by calculating its standard deviation (σRh) of an ensemble of ssDNA-grafted NPs configurations generated by MD. For the parameter space explored in this manuscript, σR h shows a peak value as a function of N, the amplitude of which depends on L, lp and R, while the broadness depends on R.

  12. Inclusive jet spectrum for small-radius jets

    NASA Astrophysics Data System (ADS)

    Dasgupta, Mrinal; Dreyer, Frédéric A.; Salam, Gavin P.; Soyez, Gregory

    2016-06-01

    Following on our earlier work on leading-logarithmic (LL R ) resummations for the properties of jets with a small radius, R, we here examine the phenomenological considerations for the inclusive jet spectrum. We discuss how to match the NLO predictions with small- R resummation. As part of the study we propose a new, physically-inspired prescription for fixed-order predictions and their uncertainties. We investigate the R-dependent part of the next-to-next-to-leading order (NNLO) corrections, which is found to be substantial, and comment on the implications for scale choices in inclusive jet calculations. We also examine hadronisation corrections, identifying potential limitations of earlier analytical work with regards to their p t -dependence. Finally we assemble these different elements in order to compare matched (N)NLO+LLR predictions to data from ALICE and ATLAS, finding improved consistency for the R-dependence of the results relative to NLO predictions.

  13. Radius of Curvature Measurements: An Independent Look at Accuracy Using Novel Optical Metrology

    NASA Technical Reports Server (NTRS)

    Taylor, Bryon; Kahan, Mark; Russell, Kevin (Technical Monitor)

    2002-01-01

    The AMSD (Advanced Mirror System Demonstrator) program mirror specifications include the ability to manufacture the mirror to a radius of curvature of 10 m +/- 1 mm and to control its radius at 30K to the same specification. Therefore, it is necessary for the Government Team to be able to measure mirror radius of curvature to an accuracy of better than 0.5 mm. This presentation discusses a novel optical metrology system for measuring radius of curvature.

  14. Maximum wind radius estimated by the 50 kt radius: improvement of storm surge forecasting over the western North Pacific

    NASA Astrophysics Data System (ADS)

    Takagi, Hiroshi; Wu, Wenjie

    2016-03-01

    Even though the maximum wind radius (Rmax) is an important parameter in determining the intensity and size of tropical cyclones, it has been overlooked in previous storm surge studies. This study reviews the existing estimation methods for Rmax based on central pressure or maximum wind speed. These over- or underestimate Rmax because of substantial variations in the data, although an average radius can be estimated with moderate accuracy. As an alternative, we propose an Rmax estimation method based on the radius of the 50 kt wind (R50). Data obtained by a meteorological station network in the Japanese archipelago during the passage of strong typhoons, together with the JMA typhoon best track data for 1990-2013, enabled us to derive the following simple equation, Rmax = 0.23 R50. Application to a recent strong typhoon, the 2015 Typhoon Goni, confirms that the equation provides a good estimation of Rmax, particularly when the central pressure became considerably low. Although this new method substantially improves the estimation of Rmax compared to the existing models, estimation errors are unavoidable because of fundamental uncertainties regarding the typhoon's structure or insufficient number of available typhoon data. In fact, a numerical simulation for the 2013 Typhoon Haiyan as well as 2015 Typhoon Goni demonstrates a substantial difference in the storm surge height for different Rmax. Therefore, the variability of Rmax should be taken into account in storm surge simulations (e.g., Rmax = 0.15 R50-0.35 R50), independently of the model used, to minimize the risk of over- or underestimating storm surges. The proposed method is expected to increase the predictability of major storm surges and to contribute to disaster risk management, particularly in the western North Pacific, including countries such as Japan, China, Taiwan, the Philippines, and Vietnam.

  15. What Is the Largest Einstein Radius in the Universe?

    SciTech Connect

    Oguri, Masamune; Blandford, Roger D.

    2008-08-05

    The Einstein radius plays a central role in lens studies as it characterizes the strength of gravitational lensing. In particular, the distribution of Einstein radii near the upper cutoff should probe the probability distribution of the largest mass concentrations in the universe. Adopting a triaxial halo model, we compute expected distributions of large Einstein radii. To assess the cosmic variance, we generate a number of Monte-Carlo realizations of all-sky catalogues of massive clusters. We find that the expected largest Einstein radius in the universe is sensitive to parameters characterizing the cosmological model, especially {sigma}{sub s}: for a source redshift of unity, they are 42{sub -7}{sup +9}, 35{sub -6}{sup +8}, and 54{sub -7}{sup +12} arcseconds (errors denote 1{sigma} cosmic variance), assuming best-fit cosmological parameters of the Wilkinson Microwave Anisotropy Probe five-year (WMAP5), three-year (WMAP3) and one-year (WMAP1) data, respectively. These values are broadly consistent with current observations given their incompleteness. The mass of the largest lens cluster can be as small as {approx} 10{sup 15} M{sub {circle_dot}}. For the same source redshift, we expect in all-sky {approx} 35 (WMAP5), {approx} 15 (WMAP3), and {approx} 150 (WMAP1) clusters that have Einstein radii larger than 2000. For a larger source redshift of 7, the largest Einstein radii grow approximately twice as large. While the values of the largest Einstein radii are almost unaffected by the level of the primordial non-Gaussianity currently of interest, the measurement of the abundance of moderately large lens clusters should probe non-Gaussianity competitively with cosmic microwave background experiments, but only if other cosmological parameters are well-measured. These semi-analytic predictions are based on a rather simple representation of clusters, and hence calibrating them with N-body simulations will help to improve the accuracy. We also find that these 'superlens

  16. The Relation Between Radius, Mass, and Incident Flux of Exoplanets

    NASA Astrophysics Data System (ADS)

    Weiss, Lauren M.; Marcy, G. W.; Rowe, J.; Isaacson, H. T.; Howard, A.; Fortney, J. J.; Miller, N.; Demory, B.; Fischer, D.; Adams, E. A.; Dupree, A. K.; Howell, S. B.; Horch, E.; Everett, M. E.; Seager, S.; Fabrycky, D. C.

    2013-01-01

    We measure the mass of a modestly irradiated giant or "warm Jupiter," KOI-94d, in order to calculate its density. We wish to determine whether this planet, which is in a 22 day orbit and receives 107 times as much incident flux as the Earth, is bloated like "hot Jupiters" or as dense as our own Jupiter. In addition to its warm Jupiter, KOI-94 hosts at least 3 smaller planets, all of which were detected through transits by the Kepler Mission. This presents the opportunity to characterize a multi-planet system and to test dynamic stability and formation theory through observations of the masses and orbital elements of these planets. With 26 radial velocity measurements of KOI-94 from the W. M. Keck Observatory/HIRES, we measure the mass of the giant planet and upper limits to the masses of the three smaller planets. Transit timing variations will allow us to hone the mass measurements of the three smaller planets. Using the KOI-94 system and all other planets with published values for both mass and radius, we establish two fundamental planes for exoplanets that relate their mass, incident flux, and radius from a few Earth masses up to ten Jupiter masses: log(Rp/RE) = 0.007 + 0.53 log(M/ME) - 0.001 log(F/[erg/s/cm^2]) for Mp < 150ME; log(Rp/RE) = 0.67 - 0.036 log(M/ME) + 0.06 log(F/[erg/s/cm^2]) for Mp > 150ME. We also solve these planes in density-mass-flux space: log(ρp/[g/cm^3]) = 0.69 - 0.57 log(M/ME) + 0.02 log(F/[erg/s/cm^2]) for Mp < 150ME; log(ρp/[g/cm^3]) = -1.23 + 1.10 log(M/ME) - 0.18 log(F/[erg/s/cm^2]) for Mp > 150ME.

  17. Percutaneous pinning of fractures of the distal radius.

    PubMed

    Alm-Paulsen, Paal Sandoe; Rod, Oyvind; Rød, Kristian; Rajabi, Benjamin; Russwurm, Harald; Finsen, Vilhjalmur

    2012-09-01

    Reduction of fractures of the distal radius is often supplemented with percutaneous pinning, but there is little evidence that this affects the clinical outcome. A total of 43 patients with pinned, and 296 with conservatively-treated, fractures were reviewed a mean of 6 (range 3-13) years after injury. We found controls among the conservatively-treated patients who matched 30 of the patients with pinned fractures with respect to age, sex, trauma energy, and radiographic measurements at injury. Clinical and radiological results of the two groups were compared and contrasted. There was a trend for better radiological results in patients with pinned fractures, but not significantly so, and no difference in clinical variables. We identified seven published randomised studies in which pinning was compared with reduction and plaster of Paris alone. Most reported better radiological results at review. The three smallest studies with the shortest follow-up reported better clinical outcome for pinned fractures, while the remaining four studies found no significant clinical benefit from pinning. Although the radiological results were improved by percutaneous pinning in addition to reduction and plaster of Paris, the clinical outcome in extra-articular and simple intra-articular fractures seemed unaffected. PMID:22694081

  18. System Estimates Radius of Curvature of a Segmented Mirror

    NASA Technical Reports Server (NTRS)

    Rakoczy, John

    2008-01-01

    A system that estimates the global radius of curvature (GRoC) of a segmented telescope mirror has been developed for use as one of the subsystems of a larger system that exerts precise control over the displacements of the mirror segments. This GRoC-estimating system, when integrated into the overall control system along with a mirror-segment- actuation subsystem and edge sensors (sensors that measure displacements at selected points on the edges of the segments), makes it possible to control the GROC mirror-deformation mode, to which mode contemporary edge sensors are insufficiently sensitive. This system thus makes it possible to control the GRoC of the mirror with sufficient precision to obtain the best possible image quality and/or to impose a required wavefront correction on incoming or outgoing light. In its mathematical aspect, the system utilizes all the information available from the edge-sensor subsystem in a unique manner that yields estimates of all the states of the segmented mirror. The system does this by exploiting a special set of mirror boundary conditions and mirror influence functions in such a way as to sense displacements in degrees of freedom that would otherwise be unobservable by means of an edge-sensor subsystem, all without need to augment the edge-sensor system with additional metrological hardware. Moreover, the accuracy of the estimates increases with the number of mirror segments.

  19. Kinetic theory of plasma adiabatic major radius compression in tokamaks

    NASA Astrophysics Data System (ADS)

    Gorelenkova, M. V.; Gorelenkov, N. N.; Azizov, E. A.; Romannikov, A. N.; Herrmann, H. W.

    1998-05-01

    In order to understand the individual charged particle behavior as well as plasma macroparameters (temperature, density, etc.) during the adiabatic major radius compression (R-compression) in a tokamak, a kinetic approach is used. The perpendicular electric field from the Ohm's law at zero resistivity is made use of in order to describe particle motion during the R-compression. Expressions for both passing and trapped particle energy and pitch angle change are derived for a plasma with high aspect ratio and circular magnetic surfaces. The particle behavior near the passing trapped boundary during the compression is studied to simulate the compression-induced collisional losses of alpha particles. Qualitative agreement is obtained with the alphas loss measurements in deuterium-tritium (D-T) experiments in the Tokamak Fusion Test Reactor (TFTR) [World Survey of Activities in Controlled Fusion Research [Nucl. Fusion special supplement (1991)] (International Atomic Energy Agency, Vienna, 1991)]. The plasma macroparameters evolution at the R-compression is calculated by solving the gyroaveraged drift kinetic equation.

  20. Placing molecules with Bohr radius resolution using DNA origami.

    PubMed

    Funke, Jonas J; Dietz, Hendrik

    2016-01-01

    Molecular self-assembly with nucleic acids can be used to fabricate discrete objects with defined sizes and arbitrary shapes. It relies on building blocks that are commensurate to those of biological macromolecular machines and should therefore be capable of delivering the atomic-scale placement accuracy known today only from natural and designed proteins. However, research in the field has predominantly focused on producing increasingly large and complex, but more coarsely defined, objects and placing them in an orderly manner on solid substrates. So far, few objects afford a design accuracy better than 5 nm, and the subnanometre scale has been reached only within the unit cells of designed DNA crystals. Here, we report a molecular positioning device made from a hinged DNA origami object in which the angle between the two structural units can be controlled with adjuster helices. To test the positioning capabilities of the device, we used photophysical and crosslinking assays that report the coordinate of interest directly with atomic resolution. Using this combination of placement and analysis, we rationally adjusted the average distance between fluorescent molecules and reactive groups from 1.5 to 9 nm in 123 discrete displacement steps. The smallest displacement step possible was 0.04 nm, which is slightly less than the Bohr radius. The fluctuation amplitudes in the distance coordinate were also small (±0.5 nm), and within a factor of two to three of the amplitudes found in protein structures. PMID:26479026

  1. Mass-radius relation of strongly magnetized white dwarfs

    NASA Astrophysics Data System (ADS)

    Bera, Prasanta; Bhattacharya, Dipankar

    2016-07-01

    We study the strongly magnetized white dwarf configurations in a self-consistent manner as a progenitor of the over-luminous type-Ia supernovae. We compute static equilibria of white dwarf stars containing a strong magnetic field and present the modification of white dwarf mass-radius relation caused by the magnetic field. From a static equilibrium study, we find that a maximum white dwarf mass of about 1.9 M_{⊙} may be supported if the interior poloidal field is as strong as approximately 10^{10} T. On the other hand, if the field is purely toroidal the maximum mass can be more than 5 M_⊙. All these modifications are mainly from the presence of Lorenz force. The effects of i) modification of equation of state due to Landau quantization ii) electrostatic interaction due to ions, ii) general relativistic calculation on the stellar structure and, iii) field geometry are also considered. These strongly magnetised configurations are sensitive to magnetic instabilities where the perturbations grow at the corresponding Alfven time scales.

  2. Placing molecules with Bohr radius resolution using DNA origami

    NASA Astrophysics Data System (ADS)

    Funke, Jonas J.; Dietz, Hendrik

    2016-01-01

    Molecular self-assembly with nucleic acids can be used to fabricate discrete objects with defined sizes and arbitrary shapes. It relies on building blocks that are commensurate to those of biological macromolecular machines and should therefore be capable of delivering the atomic-scale placement accuracy known today only from natural and designed proteins. However, research in the field has predominantly focused on producing increasingly large and complex, but more coarsely defined, objects and placing them in an orderly manner on solid substrates. So far, few objects afford a design accuracy better than 5 nm, and the subnanometre scale has been reached only within the unit cells of designed DNA crystals. Here, we report a molecular positioning device made from a hinged DNA origami object in which the angle between the two structural units can be controlled with adjuster helices. To test the positioning capabilities of the device, we used photophysical and crosslinking assays that report the coordinate of interest directly with atomic resolution. Using this combination of placement and analysis, we rationally adjusted the average distance between fluorescent molecules and reactive groups from 1.5 to 9 nm in 123 discrete displacement steps. The smallest displacement step possible was 0.04 nm, which is slightly less than the Bohr radius. The fluctuation amplitudes in the distance coordinate were also small (±0.5 nm), and within a factor of two to three of the amplitudes found in protein structures.

  3. Detection of periodic motion trajectories: Effects of frequency and radius.

    PubMed

    Wilkinson, Frances; Haque, Yousra; Or, Charles C-F; Gottlieb, Audrey S; Wilson, Hugh R

    2016-05-01

    Periodic trajectories are an important component of biological motion. Or, Thabet, Wilkinson, and Wilson (2011) studied radial frequency (RF) motion trajectory detection and concluded that, for RF2-5 trajectories, the threshold function paralleled that of static RF patterns. We have extended Or et al.'s (2011) findings to a broader range of RFs (three to 24 cycles) and across a 4-fold range of radii (1°-4°). We report that (a) thresholds for RF trajectories decrease as a power function of RF for low RF trajectories (three to six cycles) before approaching an asymptote at high RFs (12-24 cycles); (b) detection thresholds for RF trajectories scale proportionally with radius; and (c) there is no lower versus upper field advantage in the parafoveal field for stimuli displaced from fixation on the vertical midline. The results are compared to earlier findings for static RF thresholds, and we argue that our findings support the existence of parallel spatial and temporal processing channels that may contribute to both action perception and production. PMID:27183192

  4. Massive radius-dependent flow slippage in carbon nanotubes.

    PubMed

    Secchi, Eleonora; Marbach, Sophie; Niguès, Antoine; Stein, Derek; Siria, Alessandro; Bocquet, Lydéric

    2016-01-01

    Measurements and simulations have found that water moves through carbon nanotubes at exceptionally high rates owing to nearly frictionless interfaces. These observations have stimulated interest in nanotube-based membranes for applications including desalination, nano-filtration and energy harvesting, yet the exact mechanisms of water transport inside the nanotubes and at the water-carbon interface continue to be debated because existing theories do not provide a satisfactory explanation for the limited number of experimental results available so far. This lack of experimental results arises because, even though controlled and systematic studies have explored transport through individual nanotubes, none has met the considerable technical challenge of unambiguously measuring the permeability of a single nanotube. Here we show that the pressure-driven flow rate through individual nanotubes can be determined with unprecedented sensitivity and without dyes from the hydrodynamics of water jets as they emerge from single nanotubes into a surrounding fluid. Our measurements reveal unexpectedly large and radius-dependent surface slippage in carbon nanotubes, and no slippage in boron nitride nanotubes that are crystallographically similar to carbon nanotubes, but electronically different. This pronounced contrast between the two systems must originate from subtle differences in the atomic-scale details of their solid-liquid interfaces, illustrating that nanofluidics is the frontier at which the continuum picture of fluid mechanics meets the atomic nature of matter. PMID:27604947

  5. The mass-radius relationship of massive compact stars

    SciTech Connect

    Chowdhury, Partha Roy

    2015-02-24

    The properties of pure hadronic and hybrid compact stars are reviewed using nuclear equation of state (EoS) for β-equilibrated neutron star (NS) matter obtained using a density-dependent M3Y (DDM3Y) effective nucleon-nucleon interaction. Depending on the model, the energy density of quark matter can be lower than that of this nuclear EoS at higher densities, implying the possibility of transition to quark matter inside the core and the transition density depends on the particular quark matter model used. The recent observations of the binary millisecond pulsar J1614–2230 by P.B. Demorest et al. [1] and PSR J0348+0432 by J. Antoniadis et al. [2] suggest that the masses lie within 1.97 ± 0.04 M{sub ⊙} and 2.01 ± 0.04 M{sub ⊙}, respectively, where M{sub ⊙} is the solar mass. In conformity with recent observations, a pure nucleonic EoS determines that the maximum mass of NS rotating with frequency ν∼ 667 Hz below r-mode instability is ∼ 1.95 M{sub ⊙} with radius ∼ 10 km. Compact stars with quark cores rotating with same frequency have the maximum mass of ∼ 1.72 M{sub ⊙} turns out to be lower than the observed masses.

  6. MASS-RADIUS RELATIONSHIPS FOR VERY LOW MASS GASEOUS PLANETS

    SciTech Connect

    Batygin, Konstantin; Stevenson, David J.

    2013-05-20

    Recently, the Kepler spacecraft has detected a sizable aggregate of objects, characterized by giant-planet-like radii and modest levels of stellar irradiation. With the exception of a handful of objects, the physical nature, and specifically the average densities, of these bodies remain unknown. Here, we propose that the detected giant planet radii may partially belong to planets somewhat less massive than Uranus and Neptune. Accordingly, in this work, we seek to identify a physically sound upper limit to planetary radii at low masses and moderate equilibrium temperatures. As a guiding example, we analyze the interior structure of the Neptune-mass planet Kepler-30d and show that it is acutely deficient in heavy elements, especially compared with its solar system counterparts. Subsequently, we perform numerical simulations of planetary thermal evolution and in agreement with previous studies, show that generally, 10-20 M{sub Circled-Plus }, multi-billion year old planets, composed of high density cores and extended H/He envelopes can have radii that firmly reside in the giant planet range. We subject our results to stability criteria based on extreme ultraviolet radiation, as well as Roche-lobe overflow driven mass-loss and construct mass-radius relationships for the considered objects. We conclude by discussing observational avenues that may be used to confirm or repudiate the existence of putative low mass, gas-dominated planets.

  7. Mass-Radius Relation for Rocky Planets Based on PREM

    NASA Astrophysics Data System (ADS)

    Zeng, Li; Sasselov, Dimitar D.; Jacobsen, Stein B.

    2016-03-01

    Several small dense exoplanets are now known, inviting comparisons to Earth and Venus. Such comparisons require translating their masses and sizes to composition models of evolved multi-layer interior planets. Such theoretical models rely on our understanding of the Earth’s interior, as well as independently derived equations of state, but so far have not involved direct extrapolations from Earth’s seismic model: the Preliminary Reference Earth Model (PREM). To facilitate more detailed compositional comparisons between small exoplanets and the Earth, we derive here a semi-empirical mass-radius relation for two-layer rocky planets based on PREM, \\frac{R}{{R}\\oplus }=(1.07-0.21\\cdot {CMF})\\cdot {≤ft(\\frac{M}{{M}\\oplus }\\right)}1/3.7, where CMF stands for core mass fraction. It is applicable to 1 ˜ 8 M⊕ and a CMF of 0.0 ˜ 0.4. Applying this formula to Earth and Venus and several known small exoplanets with radii and masses measured to better than ˜30% precision gives a CMF fit of 0.26 ± 0.07.

  8. Recombination radius of a Frenkel pair and capture radius of a self-interstitial atom by vacancy clusters in bcc Fe

    NASA Astrophysics Data System (ADS)

    Nakashima, Kenichi; Stoller, Roger E.; Xu, Haixuan

    2015-08-01

    The recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in irradiated materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain. Values from 1.0a0 to 3.3a0 have been employed as a recombination radius in previous studies using OKMC and RT. The recombination process of a Frenkel pair is investigated at the atomic level using the self-evolved atomistic kinetic Monte Carlo (SEAKMC) method in this paper. SEAKMC calculations reveal that a self-interstitial atom recombines with a vacancy in a spontaneous reaction from several nearby sites following characteristic pathways. The recombination radius of a Frenkel pair is estimated to be 2.26a0 by taking the average of the recombination distances from 80 simulation cases. In addition, we apply these procedures to the capture radius of a self-interstitial atom by a vacancy cluster. The capture radius is found to gradually increase with the size of the vacancy cluster. The fitting curve for the capture radius is obtained as a function of the number of vacancies in the cluster.

  9. Recombination radius of a Frenkel pair and capture radius of a self-interstitial atom by vacancy clusters in bcc Fe

    SciTech Connect

    Nakashima, Kenichi; Stoller, Roger E.; Xu, Haixuan

    2015-01-01

    The recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in neutron irradiated nuclear materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain. Values from 1:0a₀ to 3:3a₀ have been employed as a recombination radius in previous studies using OKMC and RT. The recombination process of a Frenkel pair is investigated at the atomic level using the self-evolved atomistic kinetic Monte Carlo (SEAKMC) method in this paper. SEAKMC calculations reveal that a self-interstitial atom recombines with a vacancy in a spontaneous reaction from several nearby sites following characteristic pathways. The recombination radius of a Frenkel pair is estimated to be 2.26a₀ by taking the average of the recombination distances from 80 simulation cases. This value agrees well with the experimental estimate. In addition, we apply these procedures to the capture radius of a self-interstitial atom by a vacancy cluster. The capture radius is found to gradually increase with the size of the vacancy cluster. The fitting curve for the capture radius is obtained as a function of the number of vacancies in the cluster.

  10. Recombination radius of a Frenkel pair and capture radius of a self-interstitial atom by vacancy clusters in bcc Fe.

    PubMed

    Nakashima, Kenichi; Stoller, Roger E; Xu, Haixuan

    2015-08-26

    The recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in irradiated materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain. Values from 1.0a0 to 3.3a0 have been employed as a recombination radius in previous studies using OKMC and RT. The recombination process of a Frenkel pair is investigated at the atomic level using the self-evolved atomistic kinetic Monte Carlo (SEAKMC) method in this paper. SEAKMC calculations reveal that a self-interstitial atom recombines with a vacancy in a spontaneous reaction from several nearby sites following characteristic pathways. The recombination radius of a Frenkel pair is estimated to be 2.26a0 by taking the average of the recombination distances from 80 simulation cases. In addition, we apply these procedures to the capture radius of a self-interstitial atom by a vacancy cluster. The capture radius is found to gradually increase with the size of the vacancy cluster. The fitting curve for the capture radius is obtained as a function of the number of vacancies in the cluster. PMID:26241190

  11. Recombination radius of a Frenkel pair and capture radius of a self-interstitial atom by vacancy clusters in bcc Fe

    DOE PAGESBeta

    Nakashima, Kenichi; Stoller, Roger E.; Xu, Haixuan

    2015-01-01

    The recombination radius of a Frenkel pair is a fundamental parameter for the object kinetic Monte Carlo (OKMC) and mean field rate theory (RT) methods that are used to investigate irradiation damage accumulation in neutron irradiated nuclear materials. The recombination radius in bcc Fe has been studied both experimentally and numerically, however there is no general consensus about its value. The detailed atomistic processes of recombination also remain uncertain. Values from 1:0a₀ to 3:3a₀ have been employed as a recombination radius in previous studies using OKMC and RT. The recombination process of a Frenkel pair is investigated at the atomicmore » level using the self-evolved atomistic kinetic Monte Carlo (SEAKMC) method in this paper. SEAKMC calculations reveal that a self-interstitial atom recombines with a vacancy in a spontaneous reaction from several nearby sites following characteristic pathways. The recombination radius of a Frenkel pair is estimated to be 2.26a₀ by taking the average of the recombination distances from 80 simulation cases. This value agrees well with the experimental estimate. In addition, we apply these procedures to the capture radius of a self-interstitial atom by a vacancy cluster. The capture radius is found to gradually increase with the size of the vacancy cluster. The fitting curve for the capture radius is obtained as a function of the number of vacancies in the cluster.« less

  12. A Large Radius Human Centrifuge: The Human Hypergravity Havitat

    NASA Astrophysics Data System (ADS)

    van Loon, J. J. W. A.

    2008-06-01

    Life on Earth has developed at unit gravity, 9.81 m/s2, but how would plants and animals have evolved on a larger planet, i.e. larger than Earth? We are able to address this question simply by studies using centrifuges. In the past decades numerous experiments have been performed on cells, plants and animals grown for longer durations, even multi generations, under hypergravity conditions. Based on these studies we have gained interesting insights in the physiological process of these systems when exposed to artificial gravity. Animals and plants adapt themselves to this new high-g environment. Information of adaptation to hyper-g in mammals is interesting, or maybe even proof vital, for future human space flight programs especially in light of long duration missions to Moon and Mars. We know from long duration animal studies that numerous physiological processes and structures like muscles, bones, neuro-vestibular, or the cardiovascular system are affected. However, humans have never been exposed to a hyper-g environment for long durations. Human studies are mostly in the order of hours at most. Current work on human centrifuges is all focused on short arm systems to apply artificial gravity in long duration space missions. In this paper we want to address the possible usefulness of a large radius human centrifuge on Earth, or even on Moon or Mars, for both basic research and possible applications. In such a centrifuge a group of humans may be exposed to hypergravity for, in principle, an unlimited period of time.

  13. VARIATION OF INNER RADIUS OF DUST TORUS IN NGC4151

    SciTech Connect

    Koshida, Shintaro; Sakata, Yu; Sugawara, Shota; Yoshii, Yuzuru; Minezaki, Takeo; Tomita, Hiroyuki; Kobayashi, Yukiyasu; Suganuma, Masahiro; Enya, Keigo; Aoki, Tsutomu; Peterson, Bruce A.

    2009-08-01

    Long-term optical and near-infrared monitoring observations for a type 1 active galactic nucleus (AGN) NGC 4151 were carried out for six years from 2001 to 2006 by using the MAGNUM telescope, and delayed response of flux variations in the K(2.2 {mu}m) band to those in the V(0.55 {mu}m) band was clearly detected. Based on cross-correlation analysis, we precisely measured a lag time {delta}t for eight separate periods and we found that {delta}t is not constant, changing between 30 and 70 d during the monitoring period. Since {delta}t is the light travel time from the central energy source out to the surrounding dust torus, this is the first convincing evidence that the inner radius of the dust torus did change in an individual AGN. In order to relate such a change of {delta}t with a change of AGN luminosity L, we present a method of taking an average of the observed V-band fluxes that corresponds to the measured value of {delta}t, and we find that the time-changing track of NGC 4151 in the {delta}t versus L diagram during the monitoring period deviates from the relation {delta}t {proportional_to} L {sup 0.5} expected from dust reverberation. This result, combined with the elapsed time from period to period for which {delta}t was measured, indicates that the timescale of dust formation is about one year, which should be taken into account as a new constraint in future studies of dust evolution in AGNs.

  14. The radius of gyration of an apomyoglobin folding intermediate

    SciTech Connect

    Eliezer, D.; Jennings, P.A.; Wright, P.E.

    1995-10-20

    Apomyoglobin (apoMb) forms a stable compact partially folded state under acidic conditions. This {open_quotes}molten globule{close_quotes} intermediate is slightly expanded relative to the native form of the protein, with a radius of gyration (R{sub g}) of 23 ({plus_minus} 2) {Angstrom} versus 19 ({plus_minus}) {Angstrom}, and shows stable secondary structure in the A,G, and H helices. We demonstrated recently, with the use of stopped-flow circular dichroism and pulse-labeling hydrogen exchange measurements, that the earliest detectable intermediate (formed with 6 ms) in the apoMb kinetic refolding pathway closely resembles the equilibrium molten globule state populated under acid conditions. A key question remained as to how compact this kinetic intermediate is compared to the equilibrium and native states. The cooperative unfolding of the kinetic intermediate and the significant protection from amide proton exchange (as compared to corresponding isolated peptides in solution) led us to propose that the kinetic intermediate is also compact. Such a proposal could best be verified by direct determination of the size of the protein as it folds, but measurements of this nature were not feasible at the time. Newly developed improvements in time-resolved small angle x-ray scattering (SAXS) experiments allow direct measurement of the time-dependent change of R{sub g} of a protein as it folds in the millisecond to second time frame. We initiated studies of the refolding of apoMb using this technique, under conditions similar to those employed in our previous work. SAXS data collected during the first 100 ms after initiation of the refolding reaction are shown. 11 refs., 2 figs.

  15. Contact Radius and the Insulator-Metal Transition in Films Comprised of Touching Semiconductor Nanocrystals.

    PubMed

    Lanigan, Deanna; Thimsen, Elijah

    2016-07-26

    Nanocrystal assemblies are being explored for a number of optoelectronic applications such as transparent conductors, photovoltaic solar cells, and electrochromic windows. Majority carrier transport is important for these applications, yet it remains relatively poorly understood in films comprised of touching nanocrystals. Specifically, the underlying structural parameters expected to determine the transport mechanism have not been fully elucidated. In this report, we demonstrate experimentally that the contact radius, between touching heavily doped ZnO nanocrystals, controls the electron transport mechanism. Spherical nanocrystals are considered, which are connected by a circular area. The radius of this circular area is the contact radius. For nanocrystals that have local majority carrier concentration above the Mott transition, there is a critical contact radius. If the contact radius between nanocrystals is less than the critical value, then the transport mechanism is variable range hopping. If the contact radius is greater than the critical value, the films display behavior consistent with metallic electron transport. PMID:27398597

  16. A biomechanical approach to distal radius fractures for the emergency radiologist.

    PubMed

    Bunch, Paul M; Sheehan, Scott E; Dyer, George S; Sodickson, Aaron; Khurana, Bharti

    2016-04-01

    Distal radius fractures are the most common upper extremity fracture and account for approximately one sixth of all fractures treated in US emergency departments. These fractures are associated with significant morbidity and have a major economic impact. Radiographic evaluation of distal radius fractures is frequently performed in the emergency department setting, has a profound impact on initial management, and is essential to assessing the quality and relative success of the initial reduction. While the most appropriate definitive management of distal radius fractures remains controversial, overarching treatment principles reflect distal radius injury mechanisms and biomechanics. An intuitive understanding of the biomechanics of the distal radius and of common mechanisms of injury informs and improves the emergency radiologist's ability to identify key imaging findings with important management implications and to communicate the critical information that emergency physicians and orthopedic surgeons need to best manage distal radius fractures. PMID:26564022

  17. [Study on Tracheal Intubation's Circular Arc Radius Measuring Method Based on Machine Vision].

    PubMed

    Yu, Dong; Li, Genchi; Feng, Yunhao; Yang, Yonghuan; Hao, Xiali

    2015-03-01

    It is difficult to measure the circular arc radius for central angle less than 30 degrees. The existing measuring methods are of low efficiency and big error. Through designing the machine vision system and studying the image detecting method for measurement, It is obtained good results by using the new measurement for tracheal intubation's circular arc radius, Realized a rapid and accurate measurement of the circular arc radius, and expanded the application in the field of machine vision. PMID:26524788

  18. Minimum required capture radius in a coplanar model of the aerial combat problem

    NASA Technical Reports Server (NTRS)

    Breakwell, J. V.; Merz, A. W.

    1977-01-01

    Coplanar aerial combat is modeled with constant speeds and specified turn rates. The minimum capture radius which will always permit capture, regardless of the initial conditions, is calculated. This 'critical' capture radius is also the maximum range which the evader can guarantee indefinitely if the initial range, for example, is large. A composite barrier is constructed which gives the boundary, at any heading, of relative positions for which the capture radius is less than critical.

  19. A simple approach for fabrication of dual-disk electrodes with a nanometer-radius electrode and a micrometer-radius electrode.

    PubMed

    Gao, Ning; Lin, Xiaohong; Jia, Wenzhi; Zhang, Xiaoli; Jin, Wenrui

    2007-09-30

    We developed a new simple approach to fabricate dual-disk electrodes with a nanometer-radius electrode and a micrometer-radius electrode. First, nanometer-sized electrodes and micrometer-sized electrodes were constructed using 10-mum-radius metal wires, respectively. To fabricate the nanometer-sized electrode, after the apex of the 10-mum-radius metal wire was electrochemically etched to an ultrafine point with a nanometer-radius, the metal wire was electrochemically coated with a phenol-allyphenol copolymer film. The micrometer-sized electrode was fabricated by directly electrochemical coating the metal wire with an extremely thin phenol-allyphenol copolymer film. Then, the nanometer-radius electrode (the first electrode) and the 10-mum-radius electrode (the second electrode) were inserted into two sides of a thick-septum borosilicate theta (theta) tubing, respectively. The second electrode protruded from the top of the theta tubing. The top of the theta tubing was sealed with insulating ethyl alpha-cyanoacrylate. The top of the theta tubing with both electrodes was ground flat and polished successively with fine sandpaper and aluminum oxide powder until the tip of the first electrode was exposed. Since the second electrode protruded from the top of the theta tubing, its 10-mum-radius tip was naturally formed during polishing. The dual-disk electrodes were characterized by scanning electron microscopy and cyclic voltammetry. The success rate for fabrication of the dual-disk electrodes is approximately 80% due to double insurance from two coating layers of different polymers. PMID:19073075

  20. Radial shortening following a fracture of the proximal radius

    PubMed Central

    2011-01-01

    Background and purpose The Essex-Lopresti lesion is thought to be rare, with a varying degree of disruption to forearm stability probable. We describe the range of radial shortening that occurs following a fracture of the proximal radius, as well as the short-term outcome in these patients. Patients and methods Over an 18-month period, we prospectively assessed all patients with a radiographically confirmed proximal radial fracture. Patients noted to have ipsilateral wrist pain at initial presentation underwent bilateral radiography to determine whether there was disruption of the distal radio-ulnar joint suggestive of an Essex-Lopresti lesion. Outcome was assessed after a mean of 6 (1.5–12) months using clinical and radiographic results, including the Mayo elbow score (MES) and the short musculoskeletal function assessment (SMFA) questionnaire. One patient with a Mason type-I fracture was lost to follow-up after initial presentation. Results 60 patients had ipsilateral wrist pain at the initial assessment of 237 proximal radial fractures. Radial shortening of ≥ 2mm (range: 2–4mm) was seen in 22 patients (mean age 48 (19–79) years, 16 females). The most frequent mechanism of injury was a fall from standing height (10/22). 21 fractures were classified as being Mason type-I or type-II, all of which were managed nonoperatively. One Mason type-III fracture underwent acute radial head replacement. Functional outcome was assessed in 21 patients. We found an excellent or good MES in 18 of the 20 patients with a Mason type-I or type-II injury. Interpretation The incidence of the Essex-Lopresti lesion type is possibly under-reported as there is a spectrum of injuries, and subtle disruptions often go unidentified. A full assessment of all patients with a proximal radial fracture is required in order to identify these injuries, and the index of suspicion is raised as the complexity of the fracture increases. PMID:21504305

  1. Application of three-body stability to globular clusters - I. The stability radius

    NASA Astrophysics Data System (ADS)

    Kennedy, Gareth F.

    2014-11-01

    The tidal radius is commonly determined analytically by equating the tidal field of the galaxy to the gravitational potential of the cluster. Stars crossing this radius can move from orbiting the cluster centre to independently orbiting the galaxy. In this paper, the stability radius of a globular cluster is estimated using a novel approach from the theoretical standpoint of the general three-body problem. This is achieved by an analytical formula for the transition radius between stable and unstable orbits in a globular cluster. A stability analysis, outlined by Mardling, is used here to predict the occurrence of unstable stellar orbits in the outermost region of a globular cluster in a distant orbit around a galaxy. It is found that the eccentricity of the cluster-galaxy orbit has a far more significant effect on the stability radius of globular clusters than previous theoretical results of the tidal radius have found. A simple analytical formula is given for determining the transition between stable and unstable orbits, which is analogous to the tidal radius for a globular cluster. The stability radius estimate is interior to tidal radius estimates and gives the innermost region from which stars can random walk to their eventual escape from the cluster. The time-scale for this random walk process is also estimated using numerical three-body scattering experiments.

  2. Estimation of weapon-radius versus maneuverability trade-off for air-to-air combat

    NASA Technical Reports Server (NTRS)

    Kelley, H. J.; Lefton, L.

    1977-01-01

    A chase in a horizontal plane between a pursuer with a large capture radius and a more maneuverable evading vehicle is examined with constant-speed vehicle models. An approximation to the 'sidestepping' maneuver of the Homicidal Chauffeur Game is modified to account for the effect of evader turning rate, and an estimate of capture radius required is so obtained which agrees remarkably well with Cockayne's point-capture result. The maneuver assumes central importance for barrier surfaces appearing in the Game of Two Cars. Results are given for required weapon capture-radius in terms of the maneuverability of the two vehicles. Some calculations of capture radius are presented.

  3. Effect of isospin dependence of radius on transverse flow and fragmentation in isobaric pairs

    NASA Astrophysics Data System (ADS)

    Gautam, Sakshi

    2013-11-01

    We study the role of nuclear structure effects through radius in reaction dynamics via transverse flow and multifragmentation of isobaric colliding pairs. Our study reveals that isospin-dependent radius [proposed by Royer and Rousseau [Eur. Phys. J. A10.1140/epja/i2008-10745-8 42, 541 (2009)] has significant effect towards isospin effects. The collective flow behavior and fragmentation pattern of neutron-rich system with respect to neutron-deficient system is found to get reversed with isospin-dependent radius compared to that with liquid drop radius.

  4. Separatrix radius measurement of field-reversed configuration plasma in FRX-L

    SciTech Connect

    Zhang, S.Y.; Tejero, E.M.; Taccetti, J.M.; Wurden, G.A.; Intrator, T.P.; Waganaar, W.J.; Perkins, R.

    2004-10-01

    Magnetic pickup coils and single turn flux loops are installed on the FRX-L device. The combination of the two measurements provides the excluded flux radius that approximates the separatrix radius of the field-reversed configuration (FRC) plasma. Arrays of similar probes are used to map out local magnetic field dynamics beyond both ends of the theta-coil confinement region to help understand the effects of cusp locations on flux trapping during the FRC formation process. Details on the probe design and system calibrations are presented. The overall system calibration of excluded flux radius measurement is examined by replacing FRC plasma with a known radius aluminum conductor cylinder.

  5. Evaluation of the Proton Charge Radius from Electron–Proton Scattering

    SciTech Connect

    Arrington, John; Sick, Ingo

    2015-09-15

    In light of the proton radius puzzle, the discrepancy between measurements of the proton charge radius from muonic hydrogen and those from electronic hydrogen and electron–proton (e–p) scattering measurements, we re-examine the charge radius extractions from electron scattering measurements. We provide a recommended value for the proton root-mean-square charge radius, r{sub E} = 0.879 ± 0.011 fm, based on a global examination of elastic e–p scattering data. The uncertainties include contributions to account for tension between different data sets and inconsistencies between radii using different extraction procedures.

  6. Radius scaling of X-radiation from gas-puff implosions on an inductive driver

    SciTech Connect

    Mosher, D.; Stephanakis, S. J.; Apruzese, J. P.; Black, D. C.; Boller, J. R.; Commisso, R. J.; Myers, M. C.; Peterson, G. G.; Weber, B. V.; Young, F. C.

    1997-05-05

    The output of X radiation from gas-puff implosions is studied in reference to its theoretical prediction by simple model. Results show that the gas-puff radius, but not implosion time, controls radiation yield. Radius-scaling models being fairly reliable may lead to an overestimation sometimes. (AIP)

  7. Active space of pheromone plume and its relationship to effective attraction radius in applied models

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Any lure’s semiochemical release rate that is attractive to flying insects has a specific effective attraction radius (EAR) that corresponds to the lure’s orientation response strength. The EAR was defined as the radius of a passive sphere that would intercept the same number of insects as a semioch...

  8. Measuring the Radius of the Earth from a Mountain Top Overlooking the Ocean

    ERIC Educational Resources Information Center

    Gangadharan, Dhevan

    2009-01-01

    A clear view of the ocean may be used to measure the radius of the Earth. To an observer looking out at the ocean, the horizon will always form some angle [theta] with the local horizontal plane. As the observer's elevation "h" increases, so does the angle [theta]. From measurements of the elevation "h" and the angle [theta], the radius "R" of the…

  9. On the Tidal Radius of Satellites on Prograde and Retrograde Orbits

    NASA Astrophysics Data System (ADS)

    Gajda, Grzegorz; Łokas, Ewa L.

    2016-03-01

    A tidal radius is the distance from a satellite orbiting in a host potential beyond which its material is stripped by the tidal force. We derive a revised expression for the tidal radius of a rotating satellite that properly takes into account the possibility of prograde and retrograde orbits of stars. Besides the eccentricity of the satellite orbit, the tidal radius also depends on the ratio of the satellite internal angular velocity to the orbital angular velocity. We compare our formula to the results of two N-body simulations of dwarf galaxies orbiting a Milky-Way-like host on a prograde and retrograde orbit. The tidal radius for the retrograde case is larger than for the prograde. We introduce a kinematic radius that separates stars still orbiting the dwarf galaxy from those already stripped and following the potential of the host galaxy. We find that the tidal radius matches the kinematic radius very well. Our results provide a connection between the formalism of the tidal radius derivation and the theory of resonant stripping.

  10. Studying the proton 'radius' puzzle with μp elastic scattering

    SciTech Connect

    Gilman, R.

    2013-11-07

    The disagreement between the proton radius determined from muonic hydrogen and from electronic measurements is called the proton radius puzzle. The resolution of the puzzle remains unclear and appears to require new experimental results. An experiment to measure muon-proton elastic scattering is presented here.

  11. Incidence and Mortality after Distal Radius Fractures in Adults Aged 50 Years and Older in Korea

    PubMed Central

    2016-01-01

    The purpose of this study was to assess the incidence and mortality of distal radius fracture among patients 50 years of age and older with diagnosis code (ICD10; S52.5, S52.6) and treatment code using a nationwide claims database from 2008 to 2012. All patients were followed using patient identification code to identify deaths. Standardized mortality ratios (SMRs) of distal radius fracture were calculated based on age and gender-specific rates in the entire Korean population. The number of distal radius fractures increased by 54.2% over the 5-year study (48,145 in 2008 and 74,240 in 2012). The incidence of distal radius fracture increased from 367.4/100,000 in 2008 to 474.1/100,000 in 2012. The cumulative mortality rate over the first 12 months after distal radius fracture was decreased from 2.0% (968/48,145) in 2008 to 1.4% (1,045/74,240) in 2012. The mean year mortality over 5 years in men (2.6%, 1,279/50,128) over the first 12 months was 1.7-times higher than in women (1.5%, 3,952/257,045). The mean of SMR of distal radius fracture at 1 year post-fracture was 1.45 in men and 1.17 in women. This study using a nationwide database demonstrates that the distal radius fractures are increasing with a decreasing mortality in Korea. PMID:27051250

  12. The Measurement and Parameterization of Effective Radius of Droplets in Warm Stratocumulus Clouds.

    NASA Astrophysics Data System (ADS)

    Martin, G. M.; Johnson, D. W.; Spice, A.

    1994-07-01

    Observations from the Meteorological Research Flight's Hercules C-130 aircraft of the microphysical characteristics of warm stratocumulus clouds have been analyzed to investigate the variation of the effective radius of cloud droplets in layer clouds. Results from experiments in the eastern Pacific, South Atlantic, subtropical regions of the North Atlantic, and the sea areas around the British Isles are presented. In situations where entrainment effects are small the (effective radius)3 is found to be a linear function of the (volume-averaged radius)3 in a given cloud and can thus be parameterized with respect to the liquid water content and the droplet number concentration in the cloud. However, the shape of the droplet size spectrum is very dependent on the cloud condensation nuclei (CCN) characteristics below cloud base, and the relationship between effective radius and volume-averaged radius varies between maritime air masses and continental air masses. This study also details comparisons that have been made in stratocumulus between the droplet number concentrations and (a) aerosol concentrations below cloud base in the size range 0.1 to 3.0 m and (b) CCN supersaturation spectra in the boundary layer. A parameterization relating droplet concentration and aerosol concentration is suggested. The effects of nonadiabatic processes on the parameterization of effective radius are discussed. Drizzle is found to have little effect near cloud top, but in precipitating stratocumulus clouds the parameterization breaks down near cloud base. Comparisons are made between this parameterization of effective radius and others used currently or in the past.

  13. Evolution of the solar radius during the solar cycle 24 rise time

    NASA Astrophysics Data System (ADS)

    Meftah, Mustapha

    2015-08-01

    One of the real motivations to observe the solar radius is the suspicion that it might be variable. Possible temporal variations of the solar radius are important as an indicator of internal energy storage and as a mechanism for changes in the total solar irradiance. Measurements of the solar radius are of great interest within the scope of the debate on the role of the Sun in climate change. Solar energy input dominates the surface processes (climate, ocean circulation, wind, etc.) of the Earth. Thus, it appears important to know on what time scales the solar radius and other fundamental solar parameters, like the total solar irradiance, vary in order to better understand and assess the origin and mechanisms of the terrestrial climate changes. The current solar cycle is probably going to be the weakest in 100 years, which is an unprecedented opportunity for studying the variability of the solar radius during this period. This paper presents more than four years of solar radius measurements obtained with a satellite and a ground-based observatory during the solar cycle 24 rise time. Our measurements show the benefit of simultaneous measurements obtained from ground and space observatories. Space observations are a priori most favourable, however, space entails also technical challenges, a harsh environment, and a finite mission lifetime. The evolution of the solar radius during the rising phase of the solar cycle 24 show small variations that are out of phase with solar activity.

  14. Solution to the discrepancy between the seismic and photospheric solar radius

    NASA Astrophysics Data System (ADS)

    Haberreiter, M.; Kosovichev, A. G.; Schmutz, W.

    2009-04-01

    Two methods are usually used to observationally determine the solar radius: One is the observation of the intensity profile at the limb, the other one uses f-mode frequencies to derive a 'seismic' solar radius which is then corrected to optical depth unity. The two methods are inconsistent and lead to a difference in the solar radius of approx. 0.3 Mm. Based on radiative transfer calculations we show that this discrepancy can be explained by the difference between the height at disk center where tau500=1 and the inflection point of the intensity profile on the limb. We calculate the intensity profile of the limb for the MDI continuum and the continuum at 5000 A for two atmosphere structures and compare the position of the inflection points with the radius at optical depth unity. The calculated difference between the 'seismic' radius and the inflection point is 0.347 Mm with respect to optical depth unity and 0.333 Mm with respect to the Rossland mean opacity. We conclude that the standard solar radius in evolutionary models has to be lowered by 0.333 Mm and is 695.66 Mm. This correction reconciles inflection point measurements and the seismic radius within the uncertainty. This finding is very important for the analysis of the solar diameter measurements with the SODISM instrument on PICARD.

  15. Outcomes Following Operative Treatment of open Fractures of the Distal Radius: A Case Control Study

    PubMed Central

    MacKay, Brendan J; Montero, Nicole; Paksima, Nader; Egol, Kenneth A

    2013-01-01

    Purpose To report radiographic, clinical, and patient-based functional outcomes following contemporary operative treatment of patients who sustained an open distal radius fracture and compare them to a similar group of patients treated operatively for closed distal radius fractures. Methods Over five years, 601 patients with a distal radius fracture presented to our academic medical center, including one Level 1 trauma hospital, and were prospectively enrolled in an upper extremity trauma database. Patients with open distal radius fractures underwent irrigation, debridement, and operative fixation within 24 hours of presentation. Closed distal radius fractures requiring operative fixation were treated electively. Retrospective review of the database identified eighteen open fractures of the distal radius (11 type I, 6 type II, 1 type IIIa). The open fracture patients were individually matched with eighteen closed distal radius fracture patients who underwent surgical fixation based on age, sex, injury to dominant extremity, fracture pattern, and method of fracture fixation. Clinical, radiographic, patient- based functional outcomes, and complications were recorded at routine postoperative intervals. Results Follow-up was greater than 77% in both groups at all time points. The open and closed groups were similar in regards to age, gender, BMI, race, tobacco use, income, employment status, hand dominance, injury to dominant extremity, mechanism of injury, fracture classification, method of fracture fixation, and presence of concomitant injury. Postoperative complications and reoperation rates were similar between the open and closed groups. Union rates and radiographic alignment one year postoperatively were similar between the open and closed fracture groups. At final follow-up, range of motion parameters, grip strengths, DASH indices, and subjective pain scores were similar between both groups. Discussion Open distal radius fractures treated with early debridement

  16. The Evolution of Distal Radius Fracture Management – A Historical Treatise

    PubMed Central

    Diaz-Garcia, Rafael J.; Chung, Kevin C.

    2012-01-01

    Distal radius fractures have been a common affliction for millennia, but their treatment is a more recent development as a result of human erudition. While immobilization has served as the only available treatment for most of our history, many advances have been made in the management of distal radius fractures over the last century as the field of orthopedics has grown. Yet, the topic remains hotly contested in the literature, and research continues to focus upon it given the frequency of the injury. In this article, we chronicle the evolution of distal radius fracture treatment in hopes of providing context for the future that lies ahead. PMID:22554653

  17. Mass-Radius Relationships for Low-Mass Planets: From Iron Planets to Water Planets

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2007-01-01

    Transit observations, and radial velocity measurements, have begun to populate the mass radius diagram for extrasolar planets; fubture astrometric measurements and direct images promise more mass and radius information. Clearly, the bulk density of a planet indicates something about a planet s composition--but what? I will attempt to answer this question in general for low-mass planets (radius relationship: an expansion whose first term is M approx. R(sup 3).

  18. Initialization effects via the nuclear radius on transverse in-plane flow and its disappearance

    NASA Astrophysics Data System (ADS)

    Bansal, Rajni; Gautam, Sakshi

    2014-04-01

    We study the dependence of collective transverse flow and its disappearance on initialization effects via the nuclear radius within the framework of the Isospin-dependent Quantum Molecular Dynamics (IQMD) model. We calculate the balance energy using different parametrizations of the radius available in the literature for the reaction of 12C+12C to explain its measured balance energy. A mass-dependent analysis of the balance energy through out the periodic table is also carried out by changing the default liquid drop IQMD radius.

  19. Radius of the Sun from observations of the total solar eclipse of 31 July 1981.

    NASA Astrophysics Data System (ADS)

    Akimov, L. A.; Belkina, I. L.; Dyatel, N. P.; Marchenko, G. P.

    The moments of local contacts of 24 points on the east and west solar limbs are determined from the cinematographic solar continuum observations during the 31 July 1981 eclipse. The value of the solar radius averaged over limb regions with different activity was found by the least-squares method - rs = 959.97±0.04″ The solar radius estimates made separately for active and quiet limb regions reveal that the effect of active regions on the measured radius value is significant and may be as much as 0.14″

  20. Radius of the sun from observations of the total solar eclipse of July 31, 1981

    NASA Astrophysics Data System (ADS)

    Akimov, L. A.; Belkina, I. L.; Dyatel, N. P.; Marchenko, G. P.

    1993-06-01

    Moments of the local contacts at 24 points on E and W solar limbs are determined from the July 31, 1981 solar eclipse cinematographic observations in the continuum. The r.m.s. value of the solar radius, averaged over limb regions with different activity, is rs = 959.97 +/- 0.04 arcsec. The solar radius estimates made separately for limb active regions and for undisturbed ones demonstrated the significance of the active region effects on the measured solar radius (up to 0.14 arcsec).

  1. Use of High-Speed X ray and Video to Analyze Distal Radius Fracture Pathomechanics.

    PubMed

    Gutowski, Christina; Darvish, Kurosh; Liss, Frederic E; Ilyas, Asif M; Jones, Christopher M

    2015-10-01

    The purpose of this study is to investigate the failure sequence of the distal radius during a simulated fall onto an outstretched hand using cadaver forearms and high-speed X ray and video systems. This apparatus records the beginning and propagation of bony failure, ultimately resulting in distal radius or forearm fracture. The effects of 3 different wrist guard designs are investigated using this system. Serving as a proof-of-concept analysis, this study supports this imaging technique to be used in larger studies of orthopedic trauma and protective devices and specifically for distal radius fractures. PMID:26410645

  2. Effect of microstructure and notch root radius on fracture toughness of an aluminum metal matrix composite

    NASA Technical Reports Server (NTRS)

    Manoharan, M.; Lewandowski, J. J.

    1989-01-01

    Recent results on the effects of matrix aging condition (matrix temper) and notch root radius on the measured fracture toughness of a SiC particulate reinforced aluminum alloy are reviewed. Stress intensity factors at catastrophic fracture were obtained for both underaged and overaged composites reveal. The linear relation found between apparent fracture toughness and the square root of the notch root radius implies a linear dependence of the crack opening displacement on the notch root radius. The results suggest a strain controlled fracture process, and indicate that there are differences in the fracture micromechanisms of the two aging conditions.

  3. Synchronous Multicentric Giant Cell Tumour of Distal Radius and Sacrum with Pulmonary Metastases

    PubMed Central

    Tandra, Varun Sharma; Kotha, Krishna Mohan Reddy; Satyanarayana, Moorthy Gadisetti Venkata; Vadlamani, Kali Varaprasad; Yerravalli, Vyjayanthi

    2015-01-01

    Giant cell tumour (GCT) is an uncommon primary bone tumour, and its multicentric presentation is exceedingly rare. We report a case of a 45-year-old female who presented to us with GCT of left distal radius. On the skeletal survey, osteolytic lesion was noted in her right sacral ala. Biopsy confirmed both lesions as GCT. Pulmonary metastasis was also present. Resection-reconstruction arthroplasty for distal radius and thorough curettage and bone grafting of the sacral lesion were done. Multicentric GCT involving distal radius and sacrum with primary sacral involvement is not reported so far to our knowledge. PMID:26106496

  4. Synchronous Multicentric Giant Cell Tumour of Distal Radius and Sacrum with Pulmonary Metastases.

    PubMed

    Tandra, Varun Sharma; Kotha, Krishna Mohan Reddy; Satyanarayana, Moorthy Gadisetti Venkata; Vadlamani, Kali Varaprasad; Yerravalli, Vyjayanthi

    2015-01-01

    Giant cell tumour (GCT) is an uncommon primary bone tumour, and its multicentric presentation is exceedingly rare. We report a case of a 45-year-old female who presented to us with GCT of left distal radius. On the skeletal survey, osteolytic lesion was noted in her right sacral ala. Biopsy confirmed both lesions as GCT. Pulmonary metastasis was also present. Resection-reconstruction arthroplasty for distal radius and thorough curettage and bone grafting of the sacral lesion were done. Multicentric GCT involving distal radius and sacrum with primary sacral involvement is not reported so far to our knowledge. PMID:26106496

  5. Atomic radii for atoms with the 6s shell outermost: The effective atomic radius and the van der Waals radius from 55Cs to 80Hg

    NASA Astrophysics Data System (ADS)

    Tatewaki, Hiroshi; Hatano, Yasuyo; Noro, Takeshi; Yamamoto, Shigeyoshi

    2015-06-01

    We consider, for atoms from 55Cs to 80Hg, the effective atomic radius (rear), which is defined as the distance from the nucleus at which the magnitude of the electric field is equal to that in He at one half of the equilibrium bond length of He2. The values of rear are about 50% larger than the mean radius of the outermost occupied orbital of 6s, . The value of rear decreases from 55Cs to 56Ba and undergoes increases and decreases with rising nuclear charge from 57La to 70Y b. In fact rear is understood as comprising two interlaced sequences; one consists of 57La, 58Ce, and 64Gd, which have electronic configuration (4fn-1)(5d1)(6s2), and the remaining atoms have configuration (4fn)(6s2). The sphere defined by rear contains 85%-90% of the 6s electrons. From 71Lu to 80Hg the radius rear also involves two sequences, corresponding to the two configurations 5dn+16s1 and 5dn6s2. The radius rear according to the present methodology is considerably larger than rvdW obtained by other investigators, some of who have found values of rvdW close to .

  6. Radius of Curvature of the Cornea--An Experiment for the Life-Science Physics Lab

    ERIC Educational Resources Information Center

    MacLatchy, C. S.

    1978-01-01

    Presents a quantitative laboratory experiment in geometrical optics. It involves the student in the measurement of the radius of curvature of the cornea and is based on an old method devised by Kohlrausch in 1839. (Author/GA)

  7. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... an AC-powered device that is a microscope and dial gauge intended to measure the radius of a contact... notification procedures in subpart E of part 807 of this chapter, subject to the limitations in § 886.9....

  8. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... an AC-powered device that is a microscope and dial gauge intended to measure the radius of a contact... notification procedures in subpart E of part 807 of this chapter, subject to the limitations in § 886.9....

  9. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... an AC-powered device that is a microscope and dial gauge intended to measure the radius of a contact... notification procedures in subpart E of part 807 of this chapter, subject to the limitations in § 886.9....

  10. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... an AC-powered device that is a microscope and dial gauge intended to measure the radius of a contact... notification procedures in subpart E of part 807 of this chapter, subject to the limitations in § 886.9....

  11. 21 CFR 886.1430 - Ophthalmic contact lens radius measuring device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... an AC-powered device that is a microscope and dial gauge intended to measure the radius of a contact... notification procedures in subpart E of part 807 of this chapter, subject to the limitations in § 886.9....

  12. Effective charge and effective radius of water droplet in dropwise cluster

    SciTech Connect

    Shavlov, A. V.; Romanyuk, S. N.; Dzhumandzhi, V. A.

    2013-02-15

    A particle with large electric charge Z (Z Much-Greater-Than 1) and radius R{sub 0} inserted into plasma is surrounded by a plasma shell, which is stable to weak and short-term external exposures. As a result, during experiments the particle can reveal an effective charge Z* lower than the true one (Z*{<=} Z), and an effective radius R* larger than the true one (R*{>=} R{sub 0}). The effective electric charge and the effective radius of a water droplet in a dropwise cluster have been calculated using the Poisson-Boltzmann equation. It has been recognized that these parameters are not the function of a droplet's true charge, but are the function of a droplet's true size and the Debye's radius of the plasma. Experimental data on the droplet properties in a dropwise cluster have been explained.

  13. Method for Determining the Radius Vector for a Planet from Two Observations of Position

    ERIC Educational Resources Information Center

    Gainer, Michael Kizinski

    1977-01-01

    Presents a method for determining the approximate radius vector of a planet or asteroid from two closely separated observation positions, using mathematics suitable for lower division college students. (MLH)

  14. Radius construction and structure in the orb-web of Zilla diodia (Araneidae).

    PubMed

    Zschokke, S

    2000-10-01

    In orb-webs, the tension of the sticky spiral produces a centripetal force on the radii, resulting in an increase in tension along each radius from the centre of the web to the periphery. Zilla diodia (Walckenaer, 1802) atypical of araneids, was found to adapt the structure of its radii to this tension gradient by building radii that are double stranded at the periphery of the web and single stranded near the centre. Furthermore, the proportion of each radius that is doubled was found to be larger in the upper part of the web - where the overall tensions in the radii are known to be higher than in the lower part of the web. suggesting that the spider adjusts the proportion of each radius that is doubled to the overall tension in the radius. PMID:11138801

  15. Focal length and radius of curvature measurement using wavefront difference method

    NASA Astrophysics Data System (ADS)

    Yang, Zhongming; Gao, Zhishan; Wang, Shuai; Cheng, Jinlong; Yuan, Qun

    2015-10-01

    A method for measuring the focal length of the lens and the radius of curvature of the spherical surface using wavefront difference method is proposed. Based on Fizeau interferometer, an experimental system for focal length measurements is set up to verify the principle. Based on the point diffraction interferometer, an experimental system for radius of curvature measurements is proposed to verify the proposed method. With the focal length testing system, both the positive and negative lens experimental results indicate that the measurement accuracy is less than 0.16%under normal experimental environment. With the radius of curvature testing system, the radius of curvature of spherical mirrors and the surface figure can be measured in a higher precision simultaneously. The experimental results indicate that the measurement accuracy is in the order of 10-4 .

  16. Radius of curvature measurement based on wavefront difference method by the point diffraction interferometer

    NASA Astrophysics Data System (ADS)

    Yang, Zhongming; Gao, Zhishan; Yuan, Qun; Ye, Jingfei; Li, Minjue

    2014-05-01

    A method for measuring the radius of curvature with a pinhole point diffraction interferometer (PDI) is proposed. Using the wavefront difference method and the Gaussian imaging equation, the longitudinal displacement of the converging rays passing through a standard plane-parallel-plate sample in PDI interference cavity is determined. Based on this longitudinal displacement, a precise formula for radius of curvature calculation is deduced. An experimental system for radius of curvature measurements is set up to verify the principle. With this testing system, the radius of curvature of spherical mirrors and the surface figure can be measured in a higher precision simultaneously. Some sources of uncertainty in measurement are discussed based on detailed error analysis. The experimental results indicate that the measurement accuracy ΔR/R0 is in the order of 10-4.

  17. A formula for the high frequency longitudinal impedance of a tube with smoothly varying radius

    SciTech Connect

    Warnock, R.L.

    1993-04-01

    A formula for the longitudinal coupling impedance at frequencies above or below the tube cut-off is derived. The round tube is infinite in length, and has an arbitrary, smooth variation of radius over a finite interval.

  18. Reynolds Number Effects on Leading Edge Radius Variations of a Supersonic Transport at Transonic Conditions

    NASA Technical Reports Server (NTRS)

    Rivers, S. M. B.; Wahls, R. A.; Owens, L. R.

    2001-01-01

    A computational study focused on leading-edge radius effects and associated Reynolds number sensitivity for a High Speed Civil Transport configuration at transonic conditions was conducted as part of NASA's High Speed Research Program. The primary purposes were to assess the capabilities of computational fluid dynamics to predict Reynolds number effects for a range of leading-edge radius distributions on a second-generation supersonic transport configuration, and to evaluate the potential performance benefits of each at the transonic cruise condition. Five leading-edge radius distributions are described, and the potential performance benefit including the Reynolds number sensitivity for each is presented. Computational results for two leading-edge radius distributions are compared with experimental results acquired in the National Transonic Facility over a broad Reynolds number range.

  19. Ionic Radius: Its Development and Use in the Teaching of Inorganic Chemistry.

    ERIC Educational Resources Information Center

    Lewis, J. I; Waddling, R. E. L.

    1986-01-01

    The topic of ionic radius is generally given scant treatment in modern textbooks. Therefore, this article reviews some historical work and illustrates some of the applications of ionic radii in the teaching of inorganic chemistry. (JN)

  20. Design of roundness measurement model with multi-systematic error for cylindrical components with large radius

    NASA Astrophysics Data System (ADS)

    Sun, Chuanzhi; Wang, Lei; Tan, Jiubin; Zhao, Bo; Tang, Yangchao

    2016-02-01

    The paper designs a roundness measurement model with multi-systematic error, which takes eccentricity, probe offset, radius of tip head of probe, and tilt error into account for roundness measurement of cylindrical components. The effects of the systematic errors and radius of components are analysed in the roundness measurement. The proposed method is built on the instrument with a high precision rotating spindle. The effectiveness of the proposed method is verified by experiment with the standard cylindrical component, which is measured on a roundness measuring machine. Compared to the traditional limacon measurement model, the accuracy of roundness measurement can be increased by about 2.2 μm using the proposed roundness measurement model for the object with a large radius of around 37 mm. The proposed method can improve the accuracy of roundness measurement and can be used for error separation, calibration, and comparison, especially for cylindrical components with a large radius.

  1. Design of roundness measurement model with multi-systematic error for cylindrical components with large radius.

    PubMed

    Sun, Chuanzhi; Wang, Lei; Tan, Jiubin; Zhao, Bo; Tang, Yangchao

    2016-02-01

    The paper designs a roundness measurement model with multi-systematic error, which takes eccentricity, probe offset, radius of tip head of probe, and tilt error into account for roundness measurement of cylindrical components. The effects of the systematic errors and radius of components are analysed in the roundness measurement. The proposed method is built on the instrument with a high precision rotating spindle. The effectiveness of the proposed method is verified by experiment with the standard cylindrical component, which is measured on a roundness measuring machine. Compared to the traditional limacon measurement model, the accuracy of roundness measurement can be increased by about 2.2 μm using the proposed roundness measurement model for the object with a large radius of around 37 mm. The proposed method can improve the accuracy of roundness measurement and can be used for error separation, calibration, and comparison, especially for cylindrical components with a large radius. PMID:26931894

  2. Open-grown crown radius of eleven bottomland hardwood species: Prediction and use in assessing stocking

    SciTech Connect

    Goelz, J.C.G.

    1996-08-01

    Equations were prepared to predict crown radius for eleven species of open-grown bottomland hardwood trees. Crown radius was predicted as a function of diameter at breast height (dbh) and as a function of dbh, total height, and crown ratio. Equations were prepared for individual species and species groups. Pecan has the largest crowns over a broad range of dbh. Eastern cottonwood has the smallest crowns for most levels of dbh. Sweetgum has relatively small crowns for trees of small dbh, but crown radius is comparable to most species at the largest dbh. The crown radius predictions may be used to calculate crown competition factor. B-lines of stocking may be calculated that represent a stand of one species as well as a mixed-species stand of any particular species proportion.

  3. Radiation Power Affected by Current and Wall Radius in Water Cooled Vortex Wall-stabilized Arc

    NASA Astrophysics Data System (ADS)

    Iwao, Toru; Nakamura, Takaya; Yanagi, Kentaro; Yamamoto, Shinji

    2015-11-01

    The arc lighting to obtain the environment to evacuate, save the life, keep the safety and be comfortable are focus on. The lack of radiation intensity and color rendering is problem because of inappropriate energy balance. Some researchers have researched the arc lamp mixed with metal vapor for improvement of color rendering spectrum. The metal vapor can emit the high intense radiation. In addition, the radiation is derived from the high temperature medium. Because the arc temperature can be controlled by current and arc radius, the radiation can be controlled by the current and arc radius. This research elucidates the radiation power affected by the current and wall radius in wall-stabilized arc of water-cooled vortex type. As a result, the radiation power increases with increasing the square of current / square of wall radius because of the temperature distribution which is derived from the current density at the simulation.

  4. Reverberation measurements of the inner radius of the dust torus in 17 Seyfert galaxies

    SciTech Connect

    Koshida, Shintaro; Minezaki, Takeo; Yoshii, Yuzuru; Sakata, Yu; Sugawara, Shota; Kobayashi, Yukiyasu; Suganuma, Masahiro; Enya, Keigo; Tomita, Hiroyuki; Aoki, Tsutomu; Peterson, Bruce A. E-mail: minezaki@ioa.s.u-tokyo.ac.jp

    2014-06-20

    We present the results of a dust reverberation survey for 17 nearby Seyfert 1 galaxies, which provides the largest homogeneous data collection for the radius of the innermost dust torus. A delayed response of the K-band light curve after the V-band light curve was found for all targets, and 49 measurements of lag times between the flux variation of the dust emission in the K band and that of the optical continuum emission in the V band were obtained by the cross-correlation function analysis and also by an alternative method for estimating the maximum likelihood lag. The lag times strongly correlated with the optical luminosity in the luminosity range of M{sub V} = –16 to –22 mag, and the regression analysis was performed to obtain the correlation log Δt (days) = –2.11 – 0.2 M{sub V} assuming Δt∝L {sup 0.5}, which was theoretically expected. We discuss the possible origins of the intrinsic scatter of the dust lag-luminosity correlation, which was estimated to be approximately 0.13 dex, and we find that the difference of internal extinction and delayed response of changes in lag times to the flux variations could have partly contributed to intrinsic scatter. However, we could not detect any systematic change of the correlation with the subclass of the Seyfert type or the Eddington ratio. Finally, we compare the dust reverberation radius with the near-infrared interferometric radius of the dust torus and the reverberation radius of broad Balmer emission lines. The interferometric radius in the K band was found to be systematically larger than the dust reverberation radius in the same band by the about a factor of two, which could be interpreted by the difference between the flux-weighted radius and response-weighted radius of the innermost dust torus. The reverberation radius of the broad Balmer emission lines was found to be systematically smaller than the dust reverberation radius by about a factor of four to five, which strongly supports the unified

  5. Effect of tip radius on the incipient plasticity of chromium studied by nanoindentation

    SciTech Connect

    Wu, Dong; Morris, James R; Nieh, T. G.

    2015-01-01

    The onset of plasticity in Cr was investigated by nanoindentation using indenters with tip radii ranging from 60 to 759 nm. The stress for incipient plasticity was found to increase with decreasing tip radius. The cumulative pop-in probability on load could be described successfully by a combined model over the full range of tip radius, indicating that the incipient plasticity might be triggered either by the homogeneous nucleation of dislocation or by the activation of existing dislocations underneath the indenter.

  6. A high speed capacitance based system for gauging turbomachinery blading radius during the tip grind process

    NASA Astrophysics Data System (ADS)

    Sheard, A. G.; Westerman, G. C.; Killeen, B.; Fitzpatrick, M.

    1992-06-01

    A new method for measuring the rotor radius over individual blades is presented. This measurement method employs a capacitance based clearance measurement system that enables rotor radius to be measured over each blade while spinning fast enough to ensure that the blades are centrifugally loaded into their true working position. The results of an experimental program, employing a fully bladed compressor disk undertaken to ascertain system performance, are presented.

  7. Hubble Space Telescope secondary mirror vertex radius/conic constant test

    NASA Technical Reports Server (NTRS)

    Parks, Robert

    1991-01-01

    The Hubble Space Telescope backup secondary mirror was tested to determine the vertex radius and conic constant. Three completely independent tests (to the same procedure) were performed. Similar measurements in the three tests were highly consistent. The values obtained for the vertex radius and conic constant were the nominal design values within the error bars associated with the tests. Visual examination of the interferometric data did not show any measurable zonal figure error in the secondary mirror.

  8. Bilateral Distal Radius Fracture in Third Trimester of Pregnancy with Accelerated Union: A Rare Case Report

    PubMed Central

    TV, Ravikumar; P, Rahul; Samorekar, Bheemsingh

    2015-01-01

    Bilateral distal radius fracture is a rare entity. There is no literature reporting a bilateral distal radius fracture in pregnancy. Fracture healing is influenced by hormones. Hormonal changes of pregnancy will affect the healing of a fracture. A 28-year-old female at 34 wk of pregnancy sustained a bilateral distal radius fracture after a self fall. One side was managed conservatively and open reduction was done for the other side. Both fractures united at four weeks. This case is unique in three ways. First distal radius fractures commonly occur in elderly postmenopausal females due to oestrogen deficiency. In this case a distal radius fracture occurred following a self fall in third trimester of pregnancy – a hyperestrogenic state. Second the time taken for union was only four weeks signifying the hormonal effects on pregnancy on fracture healing. Third the occurrence of bilateral distal radius fracture itself is very rare in adults. In pregnancy there is a faster rate of fracture healing due to effects of oestrogen and increased cardiac output. Fractures in pregnancy require special attention. Surgical intervention should be done with a multidisciplinary approach. While management of fractures in pregnancy, effect of hormonal and physiological changes should be kept in mind. PMID:26023611

  9. Outcome Analysis of Fernandez Osteotomy in Malunited Extra-Articular Fractures of Distal Radius.

    PubMed

    Bhattacharyya, A; Kumar, S

    2016-07-01

    Deformity of wrist is very common after mal union of extra articular fractures over distal end of Radius. It causes limitation of movements too in different directions with or without pain. Deformity may be treated by different types of corrective osteotomy. We treated cases of this type of malunion with Fernandez osteotomy. This study is to observe the amount of correction and recovery of functional status in patients with malunited distal radius fractures treated with Fernandez osteotomy. This is a prospective study. We treated 10 cases of malunited radius with Fernandez osteotomy from February 2013 to October 2014 in the Departments of Orthopaedics, Medical College and Hospital, Kolkata, India. There were six males and four females with mean age of thirty years (with range from twenty to forty years. Indications for surgical intervention include pain and functional deficit severe enough to interfere significantly with daily activities. Radius is exposed through distal dorsal radial incision and radial osteotomy done two and half centimetre proximal to the wrist joint and after achieving correction; gap is filled with iliac bone graft and fixed with contoured distal radius T-plate. Follow up was for an average one year and three months. Results were excellent in one, satisfactory in four cases, good in four cases and bad in one case. Fernandez osteotomy is valuable option for correction of malunited distal radius fracture especially in young demanding patients. PMID:27612904

  10. The Effect of Pulse Length and Ejector Radius on Unsteady Ejector Performance

    NASA Technical Reports Server (NTRS)

    Wilson, Jack

    2005-01-01

    The thrust augmentation of a set of ejectors driven by a shrouded Hartmann-Sprenger tube has been measured at four different frequencies. Each frequency corresponded to a different length to diameter ratio of the pulse of air leaving the driver shroud. Two of the frequencies had length to diameter ratios below the formation number, and two above. The formation number is the value of length to diameter ratio below which the pulse converts to a vortex ring only, and above which the pulse becomes a vortex ring plus a trailing jet. A three level, three parameter Box-Behnken statistical design of experiment scheme was performed at each frequency, measuring the thrust augmentation generated by the appropriate ejectors from the set. The three parameters were ejector length, radius, and inlet radius. The results showed that there is an optimum ejector radius and length at each frequency. Using a polynomial fit to the data, the results were interpolated to different ejector radii and pulse length to diameter ratios. This showed that a peak in thrust augmentation occurs when the pulse length to diameter ratio equals the formation number, and that the optimum ejector radius is 0.87 times the sum of the vortex ring radius and the core radius.