Science.gov

Sample records for gyromagnetic radius

  1. 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

  2. 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.

  3. 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

  4. Effect of gyromagnetic fields on human prostatic adenocarcinoma cells

    PubMed Central

    Lei, Hongen; Xu, Yongde; Guan, Ruili; Li, Meng; Hui, Yu; Gao, Zhezhu; Yang, Bicheng; Xin, Zhongcheng

    2015-01-01

    Purpose To investigate the biological effect of gyromagnetic fields (GMFs) on cell proliferation and apoptosis of human prostatic adenocarcinoma cells and explore the underlying mechanisms. Methods PC-3 cells were grouped into normal control (NC) and GMF treatment groups. Cell proliferation was analyzed with kit-8 and Ki67 immunofluorescence staining, while cell apoptosis was analyzed with flow cytometry double staining of Annexin V-PE/7-AAD. The Akt and p38 MAPK/Caspase signaling pathways were analyzed by western blotting and immunofluorescence staining, and cell polarization was analyzed with PARD3. Results Cell proliferation and activity of the Akt pathway were significantly decreased by the GMF, while cell apoptosis, activity of p38 MAPK, and PARD3-positive cell number were significantly increased in the GMF group compared to the NC group. Conclusion GMFs inhibit cell proliferation, induce apoptosis, and regulate tumor cell polarity conditions, potentially through down-regulating Akt, activating the p38 MAPK/Caspase pathway, and promoting PARD3 expression in PC-3 cells. PMID:26648740

  5. Temperature dependent ferromagnetic relaxation and gyromagnetic ratio in Ni80Fe20 / Gd thin films

    NASA Astrophysics Data System (ADS)

    Khodadadi, Behrouz; Mohammadi, Jamileh; Mewes, Claudia; Mewes, Tim; Eggers, Tatiana; Miller, Casey; MINT Center Team; Rochester Institute of Technology Team

    2015-03-01

    We report on the temperature dependence of the magnetization dynamics of NiFe thin films (5nm & 10nm) capped with a 3nm Gd layer using broadband ferromagnetic resonance. We observe that the effective Gilbert damping parameter determined from the broadband measurements increases as the temperature approaches the Curie-temperature of the Gd layer. Part of the enhancement can be explained by an increase of the spin-pumping contribution to the relaxation as the temperature approaches the Curie temperature of Gd. We also measure a strong increase of the gyromagnetic ratio with decreasing temperature which resembles the increase of the gyromagnetic ratio in rare earth containing transition metals near the compensation point. This increase in the gyromagnetic ratio is expected to lead to an increased Gilbert type damping due to spin-orbit interaction, that likely also contributes to the increase in damping. NSF-CAREER Award No. 0952929 and NSF-ECCS-1231929.

  6. 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.

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

    DOE PAGES

    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

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

    NASA Astrophysics Data System (ADS)

    Chu, Ping-Han; Peng, Jen-Chieh

    2015-09-01

    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 atoms simultaneously with a π / 2 pulse, proposed for a neutron electric dipole moment experiment, is also presented.

  9. 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.

  10. Gyromagnetic Imaging: Dynamic Optical Contrast Using Gold Nanostars With Magnetic Cores

    PubMed Central

    Wei, Qingshan; Song, Hyon-Min; Leonov, Alexei P.; Hale, Jacob A.; Oh, Dongmyung; Ong, Quy K.; Ritchie, Kenneth; Wei, Alexander

    2009-01-01

    Plasmon-resonant nanoparticles with optical scattering in the near infrared (NIR) are valuable contrast agents for biophotonic imaging and may be detected at the single-particle limit against a dark background, but their contrast is often limited in environments with high noise. Here we consider gyromagnetic imaging as a dynamic mode of optical contrast, using gold nanostars with superparamagnetic cores. The nanostars exhibit polarization-sensitive NIR scattering, and can produce a frequency-modulated signal in response to a rotating magnetic field gradient. This periodic “twinkling” can be converted into Fourier-domain images with a dramatic reduction in background. We demonstrate gyromagnetic imaging of nanostars inside of tumor cells, using broadband excitation: while their time-domain signals are obscured by incoherent scattering, their Fourier-domain signals can be clearly resolved in less than a second. The gyromagnetically active nanostars do not cause a loss in viability, and can even have a mild stimulatory effect on cell growth. PMID:19435348

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. Eclipse radius measurements

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    Methods for predicting the path edges and reducing observations of total solar eclipses for determining variations of the solar radius are described. Analyzed observations of the 1925 January eclipse show a 0.7 (arc second) decrease in the solar radius during the past fifty years.

  17. Effective Cleaning Radius Studies

    SciTech Connect

    Churnetski, B.V.

    2001-10-15

    This report discusses results of testing done in the Savannah River Laboratory half tank and full tank mockup facilities using kaolin clay slurries and the relationship between cleaning radius and pump and slurry characteristics.

  18. 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.

  19. Variability of the Solar Radius

    NASA Astrophysics Data System (ADS)

    Bertello, L.; Ulrich, R. K.

    2003-05-01

    Possible temporal variability of the solar radius is important as an indicator of internal energy storage and as a mechanism for changes in the total solar irradiance (TSI). Variations in the TSI with an amplitude of 0.1% have been observed from space for more than two decades. Although the variability of this solar output is definitely established, the detailed dependence of the rate of energy output on the level of solar magnetic activity has not yet been measured with enough continuity and precision to establish the correlation throughout the full solar cycle. Changes in the solar radius could account for a significant fraction of the total irradiance variations. However, studies of the solar radius variation have reported contradictory results in the form of both correlations and anticorrelations between the solar radius and, for example, the cycle of sunspot numbers. Most of these studies however, are affected by the highly inhomogeneous data used in the analysis. This factor becomes particularly critical in the case of measurements that cover a very long period of time. We present consistent solar radius measurements obtained from the Mt Wilson synoptic programme of solar magnetic observations carried out at the 150-foot tower. Two definitions of the solar radius are used: the longest reduced record beginning in 1975 is derived from the fit of a circle to the isophote having an intensity equal to 40%\\ of the central intensity and more recently we have developed a definition based on intensity fits within 16 sectors around the solar circumference. Ulrich and Bertello (Nature, 1995, 377, 214) have made a re-analysis of an older database correcting for such effects as scattered light and atmospheric refraction. The older database is brought up to date and compared to results based on the new radius definition as well as other published radius variations. This work was supported by NASA through grants NAG5-10905 and NAG5-11708 as well as by NSF through grant ATM

  20. The Pb radius experiment (PREX)

    NASA Astrophysics Data System (ADS)

    Mammei, Juliette M.

    2013-10-01

    We report the first measurement of the parity-violating asymmetry APV in the elastic scattering of polarized electrons from 208Pb from the Lead Radius Experiment PREX which ran in Hall A at the Thomas Jefferson National Accelerator Facility (JLab). APV is sensitive to the radius of the neutron distribution Rn. The Z boson that mediates the weak neutral interaction couples mainly to neutrons and provides a clean, model-independent measurement of the RMS radius Rn of the neutron distribution in the nucleus and is a fundamental test of nuclear structure theory. The result, APV = 0.656±0.060(stat)±0.014(syst) ppm, corresponds to a difference between the radii of the neutron and proton distributions Rn-Rp = 0.33-0.18+0.16 fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. Nuclear charge radius of 8He.

    PubMed

    Mueller, P; Sulai, I A; Villari, A C C; Alcántara-Núñez, J A; Alves-Condé, R; Bailey, K; Drake, G W F; Dubois, M; Eléon, C; Gaubert, G; Holt, R J; Janssens, R V F; Lecesne, N; Lu, Z-T; O'Connor, T P; Saint-Laurent, M-G; Thomas, J-C; Wang, L-B

    2007-12-21

    The root-mean-square (rms) nuclear charge radius of 8He, the most neutron-rich of all particle-stable nuclei, has been determined for the first time to be 1.93(3) fm. In addition, the rms charge radius of 6He was measured to be 2.068(11) fm, in excellent agreement with a previous result. The significant reduction in charge radius from 6He to 8He is an indication of the change in the correlations of the excess neutrons and is consistent with the 8He neutron halo structure. The experiment was based on laser spectroscopy of individual helium atoms cooled and confined in a magneto-optical trap. Charge radii were extracted from the measured isotope shifts with the help of precision atomic theory calculations.

  7. 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.

  8. Nonbridging external fixation of distal radius fractures.

    PubMed

    Eichenbaum, Matthew D; Shin, Eon K

    2010-08-01

    Surgical management of distal radius fractures continues to evolve because of their high incidence in an increasingly active elderly population. Traditional radiocarpal external fixation relies on ligamentotaxis for fracture reduction but has several drawbacks. Nonbridging external fixation has evolved to provide early wrist mobility in the setting of anatomic fracture reduction. Several studies of the nonbridging technique have demonstrated satisfactory results in isolated nonbridging external fixation series and in comparison with traditional spanning external fixation. Nonbridging external fixation for surgical treatment of distal radius fractures can be technically demanding and requires at least 1 cm of intact volar cortex in the distal fracture fragment for successful implementation.

  9. 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

  10. 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

  11. Mass-Radius Relationships for Exoplanets

    NASA Astrophysics Data System (ADS)

    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 H2O and CH4, suggesting an "icy" composition with a relatively large core or a relatively large proportion of H2O. 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+1.2 - 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 shock and ramp

  12. 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

  13. 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.

  14. 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.

  15. The effective pore radius of screen wicks

    SciTech Connect

    Imura, Hideaki; Kozai, Hiroaki; Ikeda, Yuji

    1994-10-01

    The effective pore radius in screen-wick heat pipes was investigated, which is very important for the prediction of maximum heat transfer rates due to capillary limitation. An equation for the effective pore radius of the screen wicks was derived based on the model of the screen geometry. The capillary height for stainless steel and phosphor bronze screens was measured using water, ethyl alcohol, and Freon 113 as the test liquids. The effect of surface treatment (acid cleaning and oxidation) on the capillary height was also examined. From the comparison of the experimental data for water and ethyl alcohol with those for Freon 113, it was indicated that the contact angle was 24.2{degree} for water and 16.9{degree} for ethyl alcohol. Consequently, it was found that the effective pore radius of the screen wicks could be predicted fairly well from the expression presented in this study, and that the contact angle should be taken into consideration to evaluate the maximum capillary pressure accurately.

  16. 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.

  17. ULTRASONIC ASSESSMENT OF THE RADIUS IN VITRO

    PubMed Central

    Le Floch, Vincent; Luo, Gangming; Kaufman, Jonathan J.; Siffert, Robert S.

    2008-01-01

    The overall objective of this research is to develop an ultrasonic system for non-invasive assessment of the distal radius. The specific objective of this study was to examine the relationship between geometrical features of cortical bone and ultrasound measurements in vitro. Nineteen radii were measured in through transmission in a water bath. A 3.5 MHz rectangular (1 cm × 4.8 cm) single element transducer served as the source and a 3.5 MHz rectangular (1 cm × 4.8 cm) linear array transducer served as the receiver. The linear array consisted of 64 elements with a pitch of 0.75 mm. Ultrasound measurements were carried out at a location that was 1/3 of the length from the distal end of each radius, and two net time delay parameters, τNetDW and τNetCW, associated with a direct wave (DW) and a circumferential wave (CW), respectively, were evaluated. The cortical thickness (CT), medullar thickness (MT) and cross-sectional area (CSA) of each radius was also evaluated based on a digital image of the cross-section at the “1/3” location. The linear correlations between CT and τNetDW was r = 0.91 (p<0.001) and between MT and τNetDW - τNetCW was r = 0.63 (p<0.05). The linear correlation between CSA and a non-linear combination of the two net time delays, τNetDW and τNetCW, was r = 0.95 (p<0.001). The study shows that ultrasound measurements can be used to non-invasively assess cortical bone geometrical features in vitro as represented by cortical thickness, medullar thickness and cross-sectional area. PMID:18692295

  18. An Exoplanet Radius and Transit Timing Survey

    NASA Astrophysics Data System (ADS)

    Deming, Drake; Jennings, Jonald; Sada, Pedro

    2010-02-01

    Many exoplanet systems contain Jupiter-mass planets on close-in orbits. Theories of planetary system formation account for these hot Jupiters as being end states of inward migration. Variants of those theories also predict terrestrial planets to be captured in mean motion resonance with the hot Jupiters. A continuing explosion of discoveries by transit surveys have given us a sample of 45 hot Jupiters transiting planets brighter than V=13. A transit timing survey of these systems could detect hot Earths in resonance, via the large (~ 180 second) perturbations they induce on the giant planet transits. Moreover, the discovery photometry for these systems usually provides only relatively coarse photometric precision, but larger-aperture follow-up can determine the giant planet radius to a precision limited only by knowledge of the stellar mass, and thereby reveal the diversity of giant exoplanet structure, such as the presence of heavy element cores. The relatively large sample now available means that a radius- and transit timing-survey is well matched to classical observing and telescope scheduling. We propose continued observations to perform transit photometry using FLAMINGOS on the 2.1-meter in the J-band, where stellar limb darkening is minimal and transit photometry has excellent sensitivity to planetary radii and shifts in transit time.

  19. An Exoplanet Radius and Transit Timing Survey

    NASA Astrophysics Data System (ADS)

    Deming, Drake; Jennings, Jonald; Sada, Pedro

    2009-08-01

    Many exoplanet systems contain Jupiter-mass planets on close-in orbits. Theories of planetary system formation account for these hot Jupiters as being end states of inward migration. Variants of those theories also predict terrestrial planets to be captured in mean motion resonance with the hot Jupiters. A recent explosion of discoveries by transit surveys have given us a sample of 37 hot Jupiters transiting planets brighter than V=13. A transit timing survey of these systems could detect hot Earths in resonance, via the large (~ 180 second) perturbations they induce on the giant planet transits. Moreover, the discovery photometry for these systems usually provides only relatively coarse photometric precision, but larger-aperture follow-up can determine the giant planet radius to a precision limited only by knowledge of the stellar mass, and thereby reveal the diversity of giant exoplanet structure, such as the presence of heavy element cores. The relatively large sample now available means that a radius- and transit timing-survey is well matched to classical observing and telescope scheduling. We propose continued observations to perform transit photometry using FLAMINGOS on the 2.1-meter in the J-band, where stellar limb darkening is minimal and transit photometry has excellent sensitivity to planetary radii and shifts in transit time.

  20. Nuclear Charge Radius of Lithium-11

    SciTech Connect

    Sanchez, Rodolfo; Nortershauser, W.; Dax, A. ..; Ewald, G.; Gotte, S.; Kirchner, R. G.; Kluge, H. J.; Kuhl, T. H.; Wojtaszek, A.; Bushaw, Bruce A.; Drake, Gordon W. F.; Yan, Z. C.; Zimmermann, Claus; Albers, Daniel; Behr, John; Bricault, Pierre; Dilling, Jens; Dombsky, Marik; Lassen, J.; Levy, C.D. P.; Pearson, Matthew; Prime, Erika; Ryjkov, Vladimir L.

    2006-07-01

    We have determined the nuclear charge radius of 11Li by high-precision laser spectroscopy. The experiment was performed at the TRIUMF-ISAC facility where the 7Li-11Li isotope shift was measured in the 2s to 3s electronic transition using Doppler-free two-photon spectroscopy with a relative accuracy better than 10 5. The accuracy reached in previous experiments on the other lithium isotopes was improved. Most of the isotope shifts measured in the experiment are due to difference in the mass of the nuclei but small contributions are produced by the change in proton distribution, QED and relativistic effects have to be taken into account as well. By comparing the experimental results with sophisticated atomic calculations of the mass dependent effect the nuclear charge radii of the lithium isotopes are found to decrease monotonically from 6Li to 9Li while the nuclear charge radius of 11Li is about 11% larger than that of 9Li.

  1. What radius does the conventional keratometer measure?

    PubMed

    Bennett, A G; Rabbetts, R B

    1991-07-01

    The reflected mire images used in conventional keratometry suffer from oblique astigmatism, resulting in separated sagittal and tangential image planes. Further complications arise if the cornea is assumed to be aspherical. To investigate the consequential effects on the readings--hitherto largely neglected--ray tracing methods were applied to two hypothetical models. One was representative of modern variable-doubling constructions and the other of the Javal-Schiötz design. Both are seen to require the tangential image plane to be focused. Given a spherical cornea, the measured tangential image height can be converted into an accurate radius reading by means of a linear calibration formula. In the Javal-Schiötz design, a non-linear correction is needed for this. Appropriately calibrated in these ways, each model is shown to give readings extremely close to the sagittal radius of curvature at the point of incidence when applied to corneae of conicoidal form. Extensive numerical results are tabulated and the detailed calculating schemes illustrated by worked examples.

  2. 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

  3. 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

  4. [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

  5. 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.

  6. 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...

  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, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Corneal radius measuring device. 886.1450 Section 886.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1450 Corneal radius measuring device. (a) Identification. A corneal radius...

  9. On Galaxy Mass-Radius Relationship

    NASA Astrophysics Data System (ADS)

    Bindoni, D.; Secco, L.; Contini, E.; Caimmi, R.

    In the Clausius' virial maximum theory (TCV) [Secco and Bindoni, NewA 14, 567 (2009)] to explain the galaxy Fundamental Plane (FP) a natural explanation follows about the observed relationship between stellar mass and effective radius, M ∗ - r e , for early type galaxies (ETGs). The key of this correlation lies in the deep link which has to exist between cosmology and the existence of the FP. The general strategy consists in using the two-component tensor virial theorem to describe the virial configuration of the baryonic component of mass M B ≃ M ∗ embedded in a dark matter (DM) halo of mass M D at the end of relaxation phase. In a ΛCDM flat cosmology, starting from variance at equivalence epoch, we derive some preliminary theoretical relationships, M ∗ - r e , which are functions of mass ratio m = M D / M B . They appear to be in agreement with the trends extracted from the data of galaxy sample used by [Tortora et al., MNRAS 396, 1132 (2009)].

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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…

  15. Osteoarticular Allograft Reconstruction for an Angiosarcoma of the Distal Radius.

    PubMed

    Mavrogenis, Andreas F; Galanopoulos, John; Vottis, Christos; Megaloikonomos, Panayiotis D; Palmerini, Emanuela; Kokkalis, Zinon T

    2016-01-01

    Angiosarcoma of bone is a rare high-grade malignant vascular tumor accounting for <1% of malignant bone tumors. Tumor location in the distal radius is very rare. Complete surgical resection with limb salvage surgery or amputation is essential for the outcome of the patient. However, the literature is vague regarding the best surgical approach for resection of the distal radius and the optimal reconstruction option after a bone tumor resection. Several reconstruction techniques have been described, varying from arthrodesis to arthroplasties. In this article, we present a report of a patient with angiosarcoma of the distal radius treated with complete resection and reconstruction with a distal radius osteoarticular allograft. We discuss the advantages and the limitations of this surgical technique for the distal radius. PMID:27649764

  16. [Effect of ski tapering on turning radius and stress].

    PubMed

    Mössner, M; Nachbauer, W; Schindelwig, K

    1997-12-01

    The first part of this paper deals with the influence of the side cut on the turn radius, which was examined by measuring the turn radius of a self-running sledge-like construction and by comparing it to Howe's prediction. The turn radius at the beginning of the turn has proved to be between 65 and 85% of the theoretically expected result. In the second part a carvers turn radius was determined and the reaction force acting on the skier was calculated. The result shows a strong reduction of the turn radius along the path which increases the load on the skier. The effect of side cut and velocity on the load was examined. Using carver skis even small changes in velocity resulted in considerable load changes.

  17. Thrombocytopenia with Unilateral Dysplastic Radius- Is it Thrombocytopenia - Absent Radius (TAR) Syndrome?

    PubMed

    Kumar, Mani Kant; Chaudhary, Indradeo Prasad; Ranjan, Ram Bilas; Kumar, Prashant

    2015-03-01

    Thrombocytopenia - absent radii (TAR) syndrome is an autosomal recessive genetic rare disorder with hypomegakaryocytic thrombocytopenia and bilateral absent radius that may have additional anomalies. This disorder is characterized by thrombocytopenia resulting in potentially severe bleeding episodes primarily during infancy. We report the case of a 7-day-old term appropriate for gestational age (AGA) male baby, product of non consanguineous marriage presented with bloody loose stool, right sided upper limb deformity and paleness of the body, was diagnosed as TAR syndrome with some atypical presentation. Such type of atypical presentation has not been previously reported in a case with TAR Syndrome.Patient was managed in our hospital with packed cell transfusion and two units platelets concentrates transfusion, Intra-venous antimicrobials, and other supportive treatment. He gradually improved and was discharged after seven days of hospital stay with advice to consult orthopedic surgeon for opinion regarding limb reconstruction. PMID:25954675

  18. 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.

  19. Finite Larmor radius modification of the Mercier criterion

    SciTech Connect

    Connor, J.W.; Tang, W.M.; Allen, L.

    1984-04-01

    The finite Larmor radius modification of the Suydam criterion involves a competition between stabilizing finite Larmor radius effects and destabilizing curvature. In the case of the toroidal calculation, corresponding to the Mercier criterion, ballooning effects from regions of unfavorable curvature must be taken into account. In the case of a model equilibrium, valid near the magnetic axis, a complete solution is obtained. Results indicate that the amount of finite Larmor radius stabilization needed to overcome the effects of unfavorable average curvature increases as a function of the toroidal ballooning parameter.

  20. 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

  1. 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.

  2. 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.

  3. Experiments towards resolving the proton charge radius puzzle

    NASA Astrophysics Data System (ADS)

    Antognini, A.; Schuhmann, K.; Amaro, F. D.; Amaro, P.; Abdou-Ahmed, M.; Biraben, F.; Chen, T.-L.; Covita, D. S.; Dax, A. J.; Diepold, M.; Fernandes, L. M. P.; Franke, B.; Galtier, S.; Gouvea, A. L.; Götzfried, J.; Graf, T.; Hänsch, T. W.; Hildebrandt, M.; Indelicato, P.; Julien, L.; Kirch, K.; Knecht, A.; Kottmann, F.; Krauth, J. J.; Liu, Y.-W.; Machado, J.; Monteiro, C. M. B.; Mulhauser, F.; Nez, F.; Santos, J. P.; dos Santos, J. M. F.; Szabo, C. I.; Taqqu, D.; Veloso, J. F. C. A.; Voss, A.; Weichelt, B.; Pohl, R.

    2016-03-01

    We review the status of the proton charge radius puzzle. Emphasis is given to the various experiments initiated to resolve the conflict between the muonic hydrogen results and the results from scattering and regular hydrogen spectroscopy.

  4. Laser differential confocal radius measurement method for the cylindrical surfaces.

    PubMed

    Qiu, Lirong; Xiao, Yang; Zhao, Weiqian

    2016-05-30

    This paper proposes a laser differential confocal cylindrical radius of curvature measurement (DCCRM) method for high accuracy measurement of the radius of curvature of the cylindrical lens. Based on the property that the null point of an axial intensity curve precisely corresponds to the focus of the objective in a differential confocal system (DCS), the DCCRM uses the null point of the DCS axial intensity curve to precisely identify the cat's eye position and confocal position of the test cylindrical lens. The distance between the two positions is measured accurately using a laser distance instrument, thus achieving high precision radius measurement. In comparison with existing measurement methods, the proposed DCCRM has high measurement precision and strong environmental anti-interference capability. Theoretical analyses and preliminary experimental results indicate that the DCCRM has a relative measurement uncertainty of better than 0.03% and provides a new approach for a high precision radius measurement of the cylindrical lens.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. Optimal network modification for spectral radius dependent phase transitions

    NASA Astrophysics Data System (ADS)

    Rosen, Yonatan; Kirsch, Lior; Louzoun, Yoram

    2016-09-01

    The dynamics of contact processes on networks is often determined by the spectral radius of the networks adjacency matrices. A decrease of the spectral radius can prevent the outbreak of an epidemic, or impact the synchronization among systems of coupled oscillators. The spectral radius is thus tightly linked to network dynamics and function. As such, finding the minimal change in network structure necessary to reach the intended spectral radius is important theoretically and practically. Given contemporary big data resources such as large scale communication or social networks, this problem should be solved with a low runtime complexity. We introduce a novel method for the minimal decrease in weights of edges required to reach a given spectral radius. The problem is formulated as a convex optimization problem, where a global optimum is guaranteed. The method can be easily adjusted to an efficient discrete removal of edges. We introduce a variant of the method which finds optimal decrease with a focus on weights of vertices. The proposed algorithm is exceptionally scalable, solving the problem for real networks of tens of millions of edges in a short time.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Future treatment and research directions in distal radius fracture.

    PubMed

    Jupiter, Jesse

    2012-05-01

    Whether or not they will have their lives dramatically extended in the next few decades, it is clear that people are living longer, healthier, and more active lives. The two peak incidences of distal radius fractures will remain within the pediatric and geriatric age groups, with the latter experiencing a substantial increase in the coming years. This article attempts to project future developments with regard to epidemiology, risk and prevention, fracture assessment, and treatment of distal radius fractures, and the ever increasing concern for the economic impact of this prevalent injury.

  16. 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).

  17. 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.

  18. About the horizontal variability of effective radius in stratocumulus clouds

    NASA Astrophysics Data System (ADS)

    Magaritz-Ronen, L.; Khain, A.; Pinsky, M.

    2016-08-01

    The role of turbulent mixing in formation of low horizontal variability of effective radius near the top of nondrizzling stratocumulus clouds is investigated in simulations of clouds observed during the Second Dynamics and Chemistry of Marine Stratocumulus field experiment. The clouds are simulated using a spectral bin microphysics Lagrangian-Eulerian model consisting of ~2000 adjacent parcels moving in a turbulence-like field with observed correlation properties. The parcels interact through drop sedimentation and turbulent mixing. It was found that the effective radius variability in the horizontal direction near cloud top does not exceed ~10% of the averaged value. Three different types of cloud parcels are revealed to be differently influenced by mixing: ascending slightly diluted parcels, cloudy parcels experiencing intense mixing with parcels from inversion, and initially dry parcels. The evolution of droplet size distributions in parcels belonging to these types is investigated. It is shown that in parcels of the first two types the values of effective radii do not change or change only slightly remaining close to the adiabatic value. In initially droplet-free parcels effective radius rapidly reaches a value close to the adiabatic value, while liquid water content remains low. Therefore, turbulent mixing leads to establishing vertical profiles of effective radius, which are close to the adiabatic profile.

  19. 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.

  20. 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

  1. Focus retrocollimated interferometry for long-radius-of-curvature measurement

    NASA Astrophysics Data System (ADS)

    Xiang, Yang

    2001-12-01

    Focus retrocollimated interferometry is described for measuring long radius of curvature (>1 m), and achievable accuracy is discussed. It is shown that this method can be applied to both concave and convex spherical surfaces and can provide measurement to accuracy of 0.01-0.1%.

  2. 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.

  3. 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.

  4. [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

  5. 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.

  6. 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.

  7. 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

  8. Motion Perception During Variable-Radius Swing Motion in Darkness

    PubMed Central

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

    2009-01-01

    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 ∼0.035 m/s2 – 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/s2 at 0.9 Hz, 0.13 m/s2 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

  9. 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

  10. 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.

  11. 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.

  12. [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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Predicting jet radius in electrospinning by superpositioning exponential functions

    NASA Astrophysics Data System (ADS)

    Widartiningsih, P. M.; Iskandar, F.; Munir, M. M.; Viridi, S.

    2016-08-01

    This paper presents an analytical study of the correlation between viscosity and fiber diameter in electrospinning. Control over fiber diameter in electrospinning process was important since it will determine the performance of resulting nanofiber. Theoretically, fiber diameter was determined by surface tension, solution concentration, flow rate, and electric current. But experimentally it had been proven that significantly viscosity had an influence to fiber diameter. Jet radius equation in electrospinning process was divided into three areas: near the nozzle, far from the nozzle, and at jet terminal. There was no correlation between these equations. Superposition of exponential series model provides the equations combined into one, thus the entire of working parameters on electrospinning take a contribution to fiber diameter. This method yields the value of solution viscosity has a linear relation to jet radius. However, this method works only for low viscosity.

  18. Radius fracture from an electrical injury involving an electric guitar.

    PubMed

    Pappano, Dante

    2010-03-01

    Electrical injury ranges widely from simple shock and mild burns to more extensive superficial injury, internal injury, and mortality. Bony fracture from electrically-induced tetanic muscle contraction is a rare but recognized injury. We report the case of a 14-year-old boy who suffered a minor burn and radius fracture related to an electrical injury involving his electric guitar. An interesting pattern is emerging from available case reports of similar injuries.

  19. 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

  20. Epithelioid Hemangioendothelioma of the Distal Radius: A Case Report.

    PubMed

    Duncan, Scott F M; Krochmal, Daniel J; Craft, Randall O; Merritt, Marianne V; Smith, Anthony A

    2007-01-01

    Epithelioid hemangioendothelioma is a rare vascular tumor with cytologic behavior between angiosarcoma and hemangioma. We present the case of a 58-year-old male with primary epithelioid hemangioendothelioma of the distal radius measuring 6.2 × 5 cm with extension into the pronator quadratus and brachioradialis muscles. We discuss our approach to performing a limb-sparing resection combined with reconstruction to preserve upper extremity function. A review of the clinical, radiographic, and pathologic features of epithelioid hemangioendothelioma is also presented.

  1. 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.

  2. Effective Radius Retrieval Using Microwave and Near-Infrared Observations

    NASA Astrophysics Data System (ADS)

    Schofield, R.; Daniel, J. S.; Solomon, S.; Miller, H. L.; Portmann, R. W.; Turner, D. D.

    2005-12-01

    The role that aerosols play in changing the radiative properties of clouds is uncertain, with even the sign of the forcing undetermined. The need for remotely sensing clouds is becoming more apparent with the desire to achieve a global estimate of the radiative forcing due to changes in clouds. A new technique of combining microwave and near-infrared spectroscopic measurements of liquid water path (LWP) and path integrated liquid water path (PLWP) respectively, to obtain effective radius information is outlined. Microwave measurements of brightness temperature are made routinely as part of the Aerosol and Radiation Measurement (ARM) program. Near-infrared measurements are conducted using spectroscopic measurements made in the wavelength region between 900 and 1700 nm. The effective radius of clouds is retrieved using an optimal estimation retrieval scheme that takes into account the measurements, their uncertainties, prior knowledge of the effective radius and its uncertainty. The technique is applied to ground-based observations of clouds made during September at Barrow, Alaska, 2004.

  3. Explaining the proton radius puzzle with disformal scalars

    NASA Astrophysics Data System (ADS)

    Brax, Philippe; Burrage, Clare

    2015-02-01

    We analyze the consequences of a disformal interaction between a massless scalar and matter particles in the context of atomic physics. We focus on the displacement of the atomic energy levels that it induces, and in particular the change in the Lamb shift between the 2s and 2p states. We find that the correction to the Lamb shift depends on the mass of the fermion orbiting around the nucleus, implying a larger effect for muonic atoms. Taking the cutoff scale describing the effective scalar field theory close to the QCD scale, we find that the disformal interaction can account for the observed difference in the proton radius of muonic versus electronic hydrogen. Explaining the proton radius puzzle is only possible when the scalar field is embedded in nonlinear theories which alleviate constraints from collider and stellar physics. Short distance properties of the Galileon where nonperturbative effects in vacuum are present ensure that unitarity is preserved in high-energy particle collisions. In matter, the chameleon mechanism alleviates the constraints on disformal interactions coming from the burning rates for stellar objects. We show how to combine these two properties in a single model which renders the proposed explanation of the proton radius puzzle viable.

  4. 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.

  5. 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.

  6. Experimental investigation of streamer radius and length in SF6

    NASA Astrophysics Data System (ADS)

    Bujotzek, M.; Seeger, M.; Schmidt, F.; Koch, M.; Franck, C.

    2015-06-01

    SF6 has for decades been widely used in high voltage insulation and switching applications, e.g. in gas insulated switchgear. Despite its widespread use some important parameters, like the properties of streamers, are still not sufficiently understood. Since breakdown in SF6 always occurs via the streamer-leader transition the streamer properties are decisive for leader inception and, therefore, breakdown of the insulation. Important parameters are, for example, the streamer radius and the streamer propagation length of arrested streamers. Such properties enter in breakdown prediction models. In the present study the streamer radius and the propagation length were investigated experimentally at 50 and 100 kPa for both polarities using strongly and weakly non-uniform background fields. No experimental information was available so far for negative polarity. The resulting streamer radius scaling agrees with previous experimental results for positive polarity and with expectations from breakdown models for negative polarity. These results were similar for strongly non-uniform and weakly non-uniform background fields. A difference between the two setups was observed for the streamer lengths. It was found that for strongly non-uniform fields the streamer length scales as expected with the critical electric field but with a different field for weakly non-uniform background fields. This was similar for both polarities.

  7. 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.

  8. Complications of pediatric distal radius and forearm fractures.

    PubMed

    Chia, Benjamin; Kozin, Scott H; Herman, Martin J; Safier, Shannon; Abzug, Joshua M

    2015-01-01

    Distal radius and forearm fractures represent a large percentage of pediatric fractures. The most common mechanism of injury is a fall onto an outstretched arm, which can lead to substantial rotational displacement. If this rotational displacement is not adequately addressed, there will be resultant loss of forearm motion and subsequent limitations in performing the activities of daily living. Good initial reductions and proper casting techniques are necessary when treating distal radius and forearm fractures nonsurgically; however, maintaining an acceptable reduction is not always possible. Atraumatic reduction of a displaced physeal fracture should occur within 7 days of the injury. If an impending malunion presents at 2 weeks or later after injury, observation is warranted because of concerns about physeal arrest with repeated attempts at manipulation, and it should be followed by a later assessment of functional limitations. Pediatric patients and their parents have higher expectations for recovery, which has contributed to an increase in the surgical management of pediatric distal radius and forearm fractures. In addition, surgical interventions, such as intramedullary nailing, have their own associated complications.

  9. Quantitative, Comparative Assessment of Gait Between Single-Radius and Multi-Radius Total Knee Arthroplasty Designs.

    PubMed

    Larsen, Bethany; Jacofsky, Marc C; Jacofsky, David J

    2015-06-01

    Gait of single-radius (SR, n=16) and multi-radius (MR, n=16) posterior stabilized total knee arthroplasties was compared, along with controls (n=16), pre-op and 1 year post-op. Computer navigation and standard order sets controlled confounding variables. Post-operatively, SR knees did not differ from controls while MR knees continued to differ in important knee kinetic and kinematic properties. MR knees remained more extended (P=0.019) and had decreased power absorption (P=0.0001) during weight acceptance compared to the SR knees. Both surgical groups had similar KSS for Knee Scores (P=0.22) and Function Scores (P=0.58). The significant biomechanical differences are likely influenced by patella-femoral moment arm geometry and changing ligament laxity throughout the active range of motion.

  10. The Arches Cluster: Extended Structure and Tidal Radius

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    At a projected distance of ˜26 pc from Sgr A*, the Arches cluster provides insight into star formation in the extreme Galactic center (GC) environment. Despite its importance, many key properties, such as the cluster’s internal structure and orbital history, are not well known. We present an astrometric and photometric study of the outer region of the Arches cluster (R > 6.″25) using Hubble Space Telescope WFC3IR. Using proper motions, we calculate membership probabilities for stars down to F153M = 20 mag (˜2.5 M⊙) over a 120″ × 120″ field of view, an area 144 times larger than previous astrometric studies of the cluster. We construct the radial profile of the Arches to a radius of 75″ (˜3 pc at 8 kpc), which can be well described by a single power law. From this profile we place a 3σ lower limit of 2.8 pc on the observed tidal radius, which is larger than the predicted tidal radius (1-2.5 pc). Evidence of mass segregation is observed throughout the cluster, and no tidal tail structures are apparent along the orbital path. The absence of breaks in the profile suggests that the Arches has not likely experienced its closest approach to the GC between ˜0.2 and 1 Myr ago. If accurate, this constraint indicates that the cluster is on a prograde orbit and is located in front of the sky plane that intersects Sgr A*. However, further simulations of clusters in the GC potential are required to interpret the observed profile with more confidence.

  11. Distal Radius Isoelastic Resurfacing Prosthesis: A Preliminary Report

    PubMed Central

    Ichihara, Satoshi; Díaz, Juan José Hidalgo; Peterson, Brett; Facca, Sybille; Bodin, Frédéric; Liverneaux, Philippe

    2015-01-01

    Background Here we present a preliminary case series of unicompartmental isoelastic resurfacing prosthesis of the distal radius to treat comminuted articular fractures of osteoporotic elderly patients. Materials and Methods Our study included 12 patients, mean age 76 years, who presented with comminuted osteoporotic distal radius fracture. Because of the severity of injury and poor bone quality; osteosynthesis was not deemed to be a good option. Description of Technique The surgery was performed through a dorsal approach. The subchondral bone of the entire distal radial articular was excised and a unicompartmental prosthesis was applied. Results At an average follow-up of 32 months, the pain was 2.8/10, Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) 37.4/100, grip strength in neutral 49.9%, in supination 59.0%, and in pronation 56.2% of the contralateral normal side. The wrist ranges of motion in flexion and extension were 56.1% and 79.3%, in supination and pronation 87.7% and 91.0% of the contralateral normal side. Two patients experienced a complex regional pain syndrome (CRPS) type II; these resolved spontaneously. One patient experienced distal radioulnar joint (DRUJ) stiffness, which improved after an ulna head resection. Finally, one patient required revision surgery after a secondary traumatic fracture. Radiographically; the average volar tilt was 9.8°; the average of radial inclination was 11.6°. Conclusion The concept of a unicompartmental isoelastic resurfacing prosthesis offers a promising option for the treatment of comminuted, osteoporotic distal radius articular fractures of elderly patients. Level of Evidence IV PMID:26261738

  12. 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.

  13. Stabilisation of distal radius fractures: Lessons learned and future directions.

    PubMed

    Horst, Taylor A; Jupiter, Jesse B

    2016-02-01

    Our understanding of the diagnosis and management of distal radius fractures has been a long developed over centuries. There has been a shift in treatment of these very common injuries from closed reduction and casting to internal fixation. The answer to the best method of treatment has yet to be found. Today, we have a multitude of treatment options available with varying degrees of evidence to support their use. This review helps to illustrate the lessons we have learned and future directions for treatment.

  14. Experimental Method for Microbubbles Dynamics Monitoring and Radius Sizing

    NASA Astrophysics Data System (ADS)

    Fouan, Damien; Achaoui, Younes; Payan, Cedric; Mensah, Serge

    Rationale and aim: Within the context of divers' decompression illness prevention, ultrasonic detection and sizing of circulating microbubbles in blood is of great interest. In order to be representative of the divers gas tension level (supersaturation) and thus, to optimize decompression stages, the measurements (made in the right ventricle region) should be performed during a short period of time (ventricle filling <20 ms), efficient to detect a broad range of bubbles' radii population (radius from 20 to 200 _m) and harmless (Mechanical Index MI<0.3).

  15. 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.

  16. 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

  17. 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.

  18. 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).

  19. Distal Radius Attachments of the Radiocarpal Ligaments: An Anatomical Study

    PubMed Central

    Zumstein, M. A.; Hasan, A. P.; McGuire, D. T.; Eng, Kevin; Bain, Gregory Ian

    2013-01-01

    Background Understanding the anatomy of the ligaments of the distal radius aids in the surgical repair of ligamentous injuries and the prediction of intraarticular fracture patterns. Purposes (1) to measure the horizontal and vertical distances of the origins of the radiocarpal ligaments from the most ulnar corner of the sigmoid notch and the joint line, respectively; and (2) to express them as a percentile of the total width of the bony distal radius. Methods We dissected 8 cadaveric specimens and identified the dorsal radiocarpal, radioscaphocapitate, and the long and short radiolunate ligaments. Results The dorsal radiocarpal ligament attached from the 16th to the 52nd percentile of the radial width. The radioscaphocapitate ligament attached around the radial styloid from the 86th percentile volarly to the 87th percentile dorsally. The long radiolunate ligament attached from the 59th to the 85th percentile, and the short radiolunate ligament attached from the 14th to the 41st percentile. Discussion There was a positive correlation between the radial width and the horizontal distance of the ligaments from the sigmoid notch. These findings may aid individualized surgical repair or reconstruction adjusted to patient size and enable further standardized research on distal radial fractures and their relationship with radiocarpal ligaments. PMID:24436840

  20. 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.

  1. 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.

  2. 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.

  3. Heliocentric radius of the cosmic ray modulation boundary

    NASA Technical Reports Server (NTRS)

    Randall, B. A.; Van Allen, J. A.

    1986-01-01

    A semiempirical analysis is made of an extensive body of observed cosmic ray intensity data from Pioneers 10 and 11, and related spectral information from other authors, in order to infer the radius R of the modulation region surrounding the sun. During the period 1972-1985, the inferred values of R vary with time systematically and in a manner generally similar to that of sunspot numbers. The range of values of R is from 42 AU at the time of minimum solar activity (circa 1976) to 88 AU about 1.5 yr following the time of maximum solar activity (circa 1980). A specific, testable prediction is that Pioneer 10 will reach the modulation boundary in 1988, and will remain in its vicinity for several years thereafter.

  4. 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.

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

    PubMed

    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

  6. 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.

  7. 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.

  8. 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

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

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic contact lens radius measuring device... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1430 Ophthalmic contact lens radius measuring device. (a) Identification. An ophthalmic contact lens radius measuring device...

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

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic contact lens radius measuring device... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1430 Ophthalmic contact lens radius measuring device. (a) Identification. An ophthalmic contact lens radius measuring device...

  11. 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.

  12. Measurement of ulnar variance and radial inclination on X-rays of healed distal radius fractures. With the axis of the distal radius or ulna?

    PubMed

    Thuysbaert, Gilles; Ringburg, Akkie; Petronilia, Steven; Vanden Berghe, Alex; Hollevoet, Nadine

    2015-06-01

    Ulnar variance and radial inclination are radiological parameters frequently used to evaluate displacement of distal radius fractures. In most studies measurements are based on the long central axis of the distal radius, although the axis of the distal ulna can also be used. The purpose of this study was to determine which axis is more reliable. Four observers performed measurements on standard anteroposterior digital wrist X-rays of 20 patients taken 1 and 2 months after sustaining an extra-articular distal radius fracture. Intraobserver reliability was similar with both methods. No difference was found in interobserver reliability between both methods for ulnar variance, but for radial inclination it was better with the axis through the radius. Measurements on two X-rays of the same wrist taken at a different moment were similar with both methods. It can be concluded that the central axis of the distal radius can remain the basis to determine ulnar variance and radial inclination.

  13. Failure of dual radius hydroxyapatite-coated acetabular cups

    PubMed Central

    D'Angelo, Fabio; Molina, Mauro; Riva, Giacomo; Zatti, Giovanni; Cherubino, Paolo

    2008-01-01

    Introduction Many kind of hydroxyapatite-coated cups were used, with favorable results in short term studies; it was supposed that its use could improve osteointegration of the cup, enhancing thus stability and survivorship. The purpose of this study is to analyze the long term behavior of the hemispheric HA coated, Dual Radius Osteonics cup and to discuss the way of failure through the exam of the revised components and of both periacetabular and osteolysis tissue. Materials and Methods Between 1994 and 1997, at the Department of Orthopedic Sciences of the Insubria University, using the posterolateral approach, were implanted 276 Dual Radius Osteonics® in 256 patients, with mean age of 63 years. Results At a mean follow-up of 10 years (range 8–12 years), 183 cups in 165 patients, were available for clinical and radiographical evaluation. 22 Cups among the 183 were revised (11%). The cause of revision was aseptic loosening in 17 cases, septic loosening in one case, periprosthetic fracture in another case, osteolysis and polyethylene wear in two cases and, finally, recurrent dislocations in the last one. In the remaining patients, mean HHS increased from a preoperative value of 50,15 to a postoperative value of 92,69. The mean polyethylene wear was 1,25 mm (min. 0,08, max. 3,9 mm), with a mean annual wear of 0,17 mm. The mean acetabular migration on the two axis was 1,6 mm and 1,8 mm. Peri-acetabular osteolysis were recorded in 89% of the implants (163 cases). The cumulative survivorship (revision as endpoint) at the time was 88,9%. Conclusion Our study confirms the bad behavior of this type of cup probably related to the design, to the method of HA fixation. The observations carried out on the revised cup confirm these hypotheses but did not clarify if the third body wear could be a further problem. Another interesting aspect is the high incidence of osteolysis, which are often asymptomatic becoming a problem for the surgeon as the patient refuses the

  14. 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.

  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. 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

  17. 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.

  18. Optimum Cavity Radius Within a Bottle-Shaped Thermoacoustic Engine

    NASA Astrophysics Data System (ADS)

    Bridge, Justin; Andersen, Bonnie

    2009-10-01

    Heat energy can be used to generate acoustic energy due to thermoacoustic interactions. These engines can be used to create sound waves without any moving parts, like pistons, and could be used in space to convert solar energy into electricity. This research focused on the optimization of the geometry of bottle-shaped resonators used for thermoacoustic prime movers. These resonators have the advantage of non-harmonic overtones compared with half-wave resonators. The resonators for this research were constructed of concentric cylinders consisting of a neck piece and a cavity. The dimensions were approximately 5 cm with an ID of 2 cm for the neck and 10 cm long with IDs varying from about 2 cm to 12 cm for the cavity, producing operating frequencies ranging from approximately 1.2 to 1.5 kHz, following a theoretical model. Twelve different cavity radii were tested. The optimal cavity radius of 2.06 cm had an onset time that was 27 s faster and an onset temperature difference that was lower by 12 C than the smallest cavity (a half-wave resonator). Future research will explore the quality factor and optimum stack to surface area ratio of the engines.

  19. Thrombocytopenia-absent radius syndrome: a clinical genetic study

    PubMed Central

    Greenhalgh, K; Howell, R; Bottani, A; Ancliff, P; Brunner, H; Verschuuren-Bemel..., C; Vernon, E; Brown, K; Newbury-Ecob, R

    2002-01-01

    The thrombocytopenia-absent radius (TAR) syndrome is a congenital malformation syndrome characterised by bilateral absence of the radii and a thrombocytopenia. The lower limbs, gastrointestinal, cardiovascular, and other systems may also be involved. Shaw and Oliver in 1959 were the first to describe this condition, but it was Hall et al in 1969 who reported the first major series of patients. Since then most reports have been based on single or small numbers of cases. We report the results of a clinical study looking at the phenotype of 34 patients with TAR syndrome. All cases had a documented thrombocytopenia and bilateral radial aplasia, 47% had lower limb anomalies, 47% cow's milk intolerance, 23% renal anomalies, and 15% cardiac anomalies. Congenital anomalies not previously described in association with TAR syndrome included facial capillary haemangiomata, intracranial vascular malformation, sensorineural hearing loss, and scoliosis. Karyotype analysis, chromosome breakage studies including premature centromeric separation and fluorescence in situ hybridisation studies looking for a deletion of chromosome 22q11 were undertaken. Two abnormal karyotypes were identified. PMID:12471199

  20. Measurement of small radius gradient magnets using ion beams

    SciTech Connect

    Charles W. Schmidt et al.

    2001-07-16

    Several small and precise 90{degree}, 20-inch-radius bending and focusing magnet systems will be needed for the transport line of the Fermilab Electron Cooling Project to transport 4.36 MeV electrons. Originally, it was anticipated that these magnets would have a gradient index of {minus}1/2. To measure these magnets and complete achromatic bend modules, a well defined beam transport system was developed to determine the transfer matrix knowing the position and angle of several input and output beam rays passing through the magnet. The beam for this was a 12.5 keV proton beam that has the same magnetic rigidity as the electron beam in the final setup. The magnetic field is approximately 300 Gauss. For this purpose a high-brightness proton source was used and the beam collimated to give a low emittance ({approximately}10{sup {minus}8} m rad) pencil beam of {approximately}1 mm diameter with a current of {approximately}100 nA. Details of the system and results of measuring a magnet will be presented.

  1. 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

  2. Massive radius-dependent flow slippage in carbon nanotubes

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

    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.

  3. 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.

  4. 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.

  5. Determination of Optimal Blank Shape by Radius Vector Method

    NASA Astrophysics Data System (ADS)

    Shim, Hyun Bo; Park, Jong Kyu; Kim, Yang Soo

    2004-06-01

    A new method of optimal blank shape design for stampings of arbitrary shapes has been proposed. Similar to the sensitivity method, a past work of the present author, the basic nature of this method is iterative modification of an undeformed blank shape by adjusting the nodal positions at the boundary of the blank, until the final shape satisfies a target shape. The main difference from the sensitivity method is that both shape error measure and blank shape modification is done along the normal to a boundary direction in the current method instead of nodal moving direction as in the sensitivity method. Even though the sensitivity method has been proven to be excellent through experiment, huge computational effort is still a problem since the method requires a couple of deformation process analyses per each design stage. Differently from the sensitivity method, the present radius vector method requires only a single deformation analysis per each design step and it can handle an extraordinary motion due to a rigid-body rotation during forming. Drawings of L-shaped cup and wheel housing have been chosen as the examples to verify the present method. In every cases the optimal blank shapes have been obtained after a few times of modification. Through the investigation, the present method, which incorporates normal to boundary is found to be an excellent, or better than the sensitivity method, which incorporates moving direction, for the optimal blank design.

  6. Carpals and epiphyses of radius and ulna as age indicators.

    PubMed

    Cameriere, Roberto; Ferrante, Luigi; Mirtella, Dora; Cingolani, Mariano

    2006-05-01

    Estimation of skeletal age using radiographic images is widely used for assessing biological growth in clinical and auxological studies. The most frequent areas used for age estimation in children and adolescents are tooth and wrist/hand, both giving good results with only a low level of radiation. In particular, ossification of the carpals shows good agreement with chronological age. This study of a sample of 150 Italian children and adolescents aged between 5 and 17 years focused on analyzing the possible applications of the proportion of carpal area (Ca) mineralization as a criterion of age estimation. The ratio between the total area of carpal bones and epiphyses of the ulna and radius (Bo) and Ca was calculated. This ratio (Bo/Ca) was used for linear regression analysis. The regression model, describing age as a linear function of the ratio Bo/Ca, yielded the following equation: Age=-3.253+0.719 g+20.610 Bo/Ca, and explained 83% of the total variance (R (2)=0.83). The median of the absolute values of residuals (observed age minus predicted age) was 0.08 years, with a quartile deviation of 1.59 years, and a standard error of estimate of 1.19 years.

  7. 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.

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

    PubMed

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

    2016-09-07

    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.

  9. 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.

  10. 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.

  11. Massive radius-dependent flow slippage in carbon nanotubes

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

    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.

  12. 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

  13. 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.

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

    DOE PAGES

    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

  15. 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.

  16. 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.

  17. Effect of orifice inner lip radius on synthetic jet efficiency

    NASA Astrophysics Data System (ADS)

    Nani, David J.; Smith, Barton L.

    2012-11-01

    A synthetic jet is formed by periodic oscillation of a fluid through an orifice. The oscillatory motion is driven by a diaphragm or other driver. Previous studies have demonstrated that synthetic jet formation and time-averaged cavity pressure are a function of the orifice shape. Traditionally, the performance of the jet is evaluated with varying configurations of fixed driver input voltage or fixed driver displacement. Neither of these measures accurately reflect the efficiency of the actuator. Defining efficiency as "desired output divided by required input," these traditional measures may not account for increase in required driving current or force. A sharp inside edge of a thin synthetic jet orifice can result in separated flow and increased momentum flux (due to the decreased flow area) for a fixed driver displacement. This can lead one to believe that efficiency has been improved, when, in reality, much more power was required for the driver. Acoustic power, which is the time-average of volume flow rate through the orifice multiplied by the driving pressure, accurately accounts for the power required to drive the actuator. For any synthetic jet actuator, the power to the driver is the power to the fluid (acoustic power) divided by the driver efficiency. If we assume that the driver efficiency is not a strong function of the load, any change to the acoustic power will result in the same proportional change in the driver input power. This study investigates the efficiency of a round (axisymmetric) synthetic jet actuator as a function of the radius of curvature of the interior edge of the orifice. Simultaneous particle image velocimetry measurements at the jet exit and cavity pressure measurements are used to measure the acoustic power required to generate the jet. The resultant momentum flux of the jet is used as a measure of output of the jet. Results are obtained for a range of displacement amplitudes (or stroke lengths) and radii of curvature, while

  18. Rights and wrongs of the temporal solar radius variability

    NASA Astrophysics Data System (ADS)

    Rozelot, J. P.; Damiani, C.

    2012-10-01

    From time immemorial men have strived to measure the size of celestial bodies. Among them, the diameter of the Sun was a source of curiosity and study. Tackled by Greek astronomers from a geometric point of view, an estimate, although incorrect, has been first determined, not truly called into question for several centuries. One must wait up to the XVIIth century to get the first precise determinations made by the French school of astronomy. Gradually, as the techniques were more and more sophisticated, many other solar diameter measurements were carried out, notably in England, Germany, Italy and US. However, even with instruments at the cutting edge of progress, no absolute value of the solar diameter has been provided yet, even if the community has adopted a canonical radius of 959''&dotbelow;63, given in all ephemeris since the end of the XIXth century. One of the major difficulties is to define a correct solar diameter. Another issue is the possible temporal variability of the size of the Sun, as first advocated at the end of the XIXth century by the Italian school. Today, this question is just on the way to being solved in spite of considerable efforts developed on ground-based facilities or on board space experiments. We will here give a review of some of the most remarkable techniques used in the past, emphasising how incorrect measurements have driven new ideas, leading to develop new statements for the underlying physics. On such new grounds, it can be speculated that the roundness of the Sun is not perfect, but developing a thin "cantaloupe skin" in periods of higher activity, with departures from sphericity being inevitably bounded by a few kilometers (around 80 km or 10 to 15 mas).

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. Brodie's abscess of the distal radius: an unusual complication after percutaneous pinning.

    PubMed

    Johnson, Jeff W; Bindra, Randip R

    2008-12-01

    We report a case of Brodie's abscess of the distal radius that presented 4 years after closed reduction and percutaneous pinning for a closed distal radius fracture. This condition has not been previously reported in the adult distal radius and we detail the clinical features and imaging findings. We also present a new way of management of Brodie's abscess using injectable bone substitute along with adjunctive parenteral antibiotic therapy.

  5. Brodie’s Abscess of the Distal Radius: An Unusual Complication after Percutaneous Pinning

    PubMed Central

    Bindra, Randip R.

    2008-01-01

    We report a case of Brodie’s abscess of the distal radius that presented 4 years after closed reduction and percutaneous pinning for a closed distal radius fracture. This condition has not been previously reported in the adult distal radius and we detail the clinical features and imaging findings. We also present a new way of management of Brodie’s abscess using injectable bone substitute along with adjunctive parenteral antibiotic therapy. PMID:18780011

  6. 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

  7. 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.

  8. On the critical flame radius and minimum ignition energy for spherical flame initiation

    SciTech Connect

    Chen, Zheng; Burke, M. P.; Ju, Yiguang

    2011-01-01

    Spherical flame initiation from an ignition kernel is studied theoretically and numerically using different fuel/oxygen/helium/argon mixtures (fuel: hydrogen, methane, and propane). The emphasis is placed on investigating the critical flame radius controlling spherical flame initiation and its correlation with the minimum ignition energy. It is found that the critical flame radius is different from the flame thickness and the flame ball radius and that their relationship depends strongly on the Lewis number. Three different flame regimes in terms of the Lewis number are observed and a new criterion for the critical flame radius is introduced. For mixtures with Lewis number larger than a critical Lewis number above unity, the critical flame radius is smaller than the flame ball radius but larger than the flame thickness. As a result, the minimum ignition energy can be substantially over-predicted (under-predicted) based on the flame ball radius (the flame thickness). The results also show that the minimum ignition energy for successful spherical flame initiation is proportional to the cube of the critical flame radius. Furthermore, preferential diffusion of heat and mass (i.e. the Lewis number effect) is found to play an important role in both spherical flame initiation and flame kernel evolution after ignition. It is shown that the critical flame radius and the minimum ignition energy increase significantly with the Lewis number. Therefore, for transportation fuels with large Lewis numbers, blending of small molecule fuels or thermal and catalytic cracking will significantly reduce the minimum ignition energy.

  9. 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.

  10. 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.

  11. 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…

  12. 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.

  13. COUPLED EVOLUTION WITH TIDES OF THE RADIUS AND ORBIT OF TRANSITING GIANT PLANETS: GENERAL RESULTS

    SciTech Connect

    Ibgui, Laurent; Burrows, Adam E-mail: burrows@astro.princeton.edu

    2009-08-01

    Some transiting extrasolar giant planets (EGPs) have measured radii larger than predicted by the standard theory. In this paper, we explore the possibility that an earlier episode of tidal heating can explain such radius anomalies and apply the formalism we develop to HD 209458b as an example. We find that for strong enough tides the planet's radius can undergo a transient phase of inflation that temporarily interrupts canonical, monotonic shrinking due to radiative losses. Importantly, an earlier episode of tidal heating can result in a planet with an inflated radius, even though its orbit has nearly circularized. Moreover, we confirm that at late times, and under some circumstances, by raising tides on the star itself a planet can spiral into its host. We note that a 3x to 10x solar planet atmospheric opacity with no tidal heating is sufficient to explain the observed radius of HD 209458b. However, our model demonstrates that with an earlier phase of episodic tidal heating, we can fit the observed radius of HD 209458b even with lower (solar) atmospheric opacities. This work demonstrates that, if a planet is left with an appreciable eccentricity after early inward migration and/or dynamical interaction, coupling radius and orbit evolution in a consistent fashion that includes tidal heating, stellar irradiation, and detailed model atmospheres might offer a generic solution to the inflated radius puzzle for transiting EGPs such as WASP-12b, TrES-4, and WASP-6b.

  14. 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.

  15. 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

  16. Comparison of continuous and discrete frequency-versus-radius frequency-modulated reticles.

    PubMed

    Taylor, J S; Driggers, R G; Halford, C E; Sanders, J S; Griffin, S T; Wellfare, M

    1992-04-01

    We present a general expression for the transmission function of the discrete frequency-versus-radius reticle and compare such a reticle with the more common continuous reticle. A discrete form of the frequency-versus-radius reticle has an integer number of chopping cycles on a single radius. The discreteform limits the resolution of the reticle in the radial direction, but this limit is not severe for small-target images. However, since no phase reversal occurs, electronic processing is simplified. PMID:20720799

  17. Linear stability of circular Couette flow in the limit of small radius ratio

    NASA Astrophysics Data System (ADS)

    Pearlstein, Arne J.

    2005-11-01

    In the context of a detailed study of the linear stability of spiral Poiseuille flow at small radius ratio (Cotrell and Pearlstein, J. Fluid Mech., in press), we have shown that in the limiting case of no rotation, annular Poiseuille flow is linearly stable at all Re, provided that the radius ratio lies below a critical value. Here, we consider the other limiting case, of no axial flow, and report a numerical investigation of the stability of circular Couette flow for small radius ratio. The results are compared to experimental work of Theodorsen for a whirling shaft in an unbounded, otherwise quiescent fluid.

  18. 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).

  19. 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

  20. A new method on measuring radius of curvature of a conic aspherical mirror

    NASA Astrophysics Data System (ADS)

    Huang, Chuan-ke; Wu, Yong-qian; Fan, Bin; Yan, Feng-tao; Liu, Feng-wei; Zhang, Yong-hong

    2014-09-01

    We present a method to measure the radius of curvature of a concave conic asphere. By analysis the central area of the asphere, we can measure the radius of an arbitrary point in the central area instead of the vertex of asphere. In the procedure, we firstly adjust the interferometer until the interferogram of the central area approach nulls, then put the laser tracker ball at the beam focus of the interferometer and move the tracker ball to touch the central area of the aspherical surface to get the two positions. With these measurement data, we can calculate the radius of curvature of the aspherical vertex and its uncertainty.

  1. 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″

  2. 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).

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. Concurrent Minimally Invasive Carpal Tunnel Release Techniques in Distal Radius Open Reduction Internal Fixation.

    PubMed

    Low, O-Wern; Cheah, Andre E J

    2016-02-01

    Carpal tunnel syndrome is a common complication associated with distal radius fractures. Open carpal tunnel release in the same setting as open reduction and internal fixation of distal radius fractures is widely accepted. In this paper, we describe the technical details of a minimally invasive carpal tunnel release in the same setting as the fixation of a distal radius fracture via the same incision. Two options of minimally invasive techniques are described: The Knifelight® (Stryker, Kalamazoo, Michigan, USA) instrument and the single portal carpal tunnel release system (Agee, 3M Healthcare, St Paul, Minnesota, USA). Being well known and accepted techniques of carpal tunnel release, we believe that the techniques described in this paper provide a viable alternative for carpal tunnel release in the setting of distal radius fracture fixation; with the added advantages of the original minimally invasive techniques. PMID:27454517

  8. 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)

  9. Self-equilibration of the radius distribution in self-catalyzed GaAs nanowires

    NASA Astrophysics Data System (ADS)

    Leshchenko, E. D.; Turchina, M. A.; Dubrovskii, V. G.

    2016-08-01

    This work addresses the evolution of radius distribution function in self-catalyzed vapor-liquid-solid growth of GaAs nanowires from Ga droplets. Different growth regimes are analyzed depending on the V/III flux ratio. In particular, we find a very unusual selfequilibration regime in which the radius distribution narrows up to a certain stationary radius regardless of the initial size distribution of Ga droplets. This requires that the arsenic vapor flux is larger than the gallium one and that the V/III influx imbalance is compensated by a diffusion flux of gallium adatoms. Approximate analytical solution is compared to the numerical radius distribution obtained by solving the corresponding Fokker-Planck equation by the implicit difference scheme.

  10. 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

  11. 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)

  12. Using a video camera to measure the radius of the Earth

    NASA Astrophysics Data System (ADS)

    Carroll, Joshua; Hughes, Stephen

    2013-11-01

    A simple but accurate method for measuring the Earth’s radius using a video camera is described. A video camera was used to capture a shadow rising up the wall of a tall building at sunset. A free program called ImageJ was used to measure the time it took the shadow to rise a known distance up the building. The time, distance and length of the sidereal day were used to calculate the radius of the Earth. The radius was measured as 6394.3 ± 118 km, which is within 1.8% of the accepted average value of 6371 km and well within the experimental error. The experiment is suitable as a high school or university project and should produce a value for Earth’s radius within a few per cent at latitudes towards the equator, where at some times of the year the ecliptic is approximately normal to the horizon.

  13. 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.

  14. 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)

  15. 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

  16. Critical loss radius in a Penning trap subject to multipole fields

    SciTech Connect

    Fajans, J.; Madsen, N.; Robicheaux, F.

    2008-03-15

    When particles in a Penning trap are subject to a magnetic multipole field, those beyond a critical radius will be lost. The critical radius depends on the history by which the field is applied, and can be much smaller if the particles are injected into a preexisting multipole than if the particles are subject to a ramped multipole. Both cases are relevant to ongoing experiments designed to trap antihydrogen.

  17. A method for measuring the radius of curvature of a spherical mirror

    NASA Astrophysics Data System (ADS)

    Engelen, J.; El-Zaiat, S. Y.; Missotten, L.

    1992-01-01

    Evan's method for measuring the radius of curvature of both convex and concave spherical mirrors is adapted and applied. The optical set-up is modified by adding a beam splitter, and a screen with two pinholes at a distance d apart. The laser source and the mirror under test remain fixed; this greatly facilitates the displacement measurements. The quartic equation of which one of the roots gives the radius of curvature of the mirror under test is derived without approximation.

  18. 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.

  19. Carpal tunnel syndrome: A rare manifestation of distal radius osteoid osteoma.

    PubMed

    Basran, Sukhvinder Singh; Kumar, Sandeep; Jameel, Javed; Sajid, Imran

    2015-09-01

    Osteoid Osteoma is a benign bone tumor that normally affects long bones and rarely affects distal radius. Because of its nonspecific presentation in the wrist, it remains a diagnostic challenge. We report an unusual case of Osteoid Osteoma at distal radius having symptoms resembling that of carpal tunnel syndrome. The diagnosis was confirmed preoperatively with X-rays; bone scintigraphy, CT, and MRI, later histological examination confirmed the diagnoses. Surgical excision lead to a dramatic improvement in the condition of the patient.

  20. 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

  1. Measurement of super large radius optics in the detection of gravitational waves

    NASA Astrophysics Data System (ADS)

    Yang, Cheng; Han, Sen; Wu, Quanying; Liang, Binming; Hou, Changlun

    2015-10-01

    The existence of Gravitational Wave (GW) is one of the greatest predictions of Einstein's relative theory. It has played an important part in the radiation theory, black hole theory, space explore and so on. The GW detection has been an important aspect of modern physics. With the research proceeding further, there are still a lot of challenges existing in the interferometer which is the key instrument in GW detection especially the measurement of the super large radius optics. To solve this problem, one solution , Fizeau interference, for measuring the super large radius has been presented. We change the tradition that curved surface must be measured with a standard curved surface. We use a flat mirror as a reference flat and it can lower both the cost and the test requirement a lot. We select a concave mirror with the radius of 1600mm as a sample. After the precision measurement and analysis, the experimental results show that the relative error of radius is better than 3%, and it can fully meet the requirements of the measurement of super large radius optics. When calculating each pixel with standard cylinder, the edges are not sharp because of diffraction or some other reasons, we detect the edge and calculate the diameter of the cylinder automatically, and it can improve the precision a lot. In general, this method is simple, fast, non-traumatic, and highly precision, it can also provide us a new though in the measurement of super large radius optics.

  2. Effects of corner radius on periodic nanoantenna for surface-enhanced Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Chao, Bo-Kai; Lin, Shih-Che; Nien, Li-Wei; Li, Jia-Han; Hsueh, Chun-Hway

    2015-12-01

    Corner radius is a concept to approximate the fabrication limitation due to the effective beam broadening at the corner in using electron-beam lithography. The purpose of the present study is to investigate the effects of corner radius on the electromagnetic field enhancement and resonance wavelength for three periodic polygon dimers of bowtie, twin square, and twin pentagon. The enhancement factor of surface-enhanced Raman spectroscopy due to the localized surface plasmon resonances in fabricated gold bowtie nanostructures was investigated using both Raman spectroscopy and finite-difference time-domain simulations. The simulated enhancement factor versus corner radius relation was in agreement with measurements and it could be fitted by a power-law relation. In addition, the resonance wavelength showed blue shift with the increasing corner radius because of the distribution of concentrated charges in a larger area. For different polygons, the corner radius instead of the tip angle is the dominant factor of the electromagnetic field enhancement because the surface charges tend to localize at the corner. Greater enhancements can be obtained by having both the smaller gap and sharper corner although the corner radius effect on intensity enhancement is less than the gap size effect.

  3. Weak charge form factor and radius of 208Pb through parity violation in electron scattering

    DOE PAGES

    Horowitz, C. J.; Ahmed, Z.; Jen, C. -M.; Rakhman, A.; Souder, P. A.; Dalton, M. M.; Liyanage, N.; Paschke, K. D.; Saenboonruang, K.; Silwal, R.; et al

    2012-03-26

    We use distorted wave electron scattering calculations to extract the weak charge form factor FW(more » $$\\bar{q}$$), the weak charge radius RW, and the point neutron radius Rn, of 208Pb from the PREX parity violating asymmetry measurement. The form factor is the Fourier transform of the weak charge density at the average momentum transfer $$\\bar{q}$$ = 0.475 fm-1. We find FW($$\\bar{q}$$) = 0.204 ± 0.028(exp) ± 0.001(model). We use the Helm model to infer the weak radius from FW($$\\bar{q}$$). We find RW = 5.826 ± 0.181(exp) ± 0.027(model) fm. Here the exp error includes PREX statistical and systematic errors, while the model error describes the uncertainty in RW from uncertainties in the surface thickness σ of the weak charge density. The weak radius is larger than the charge radius, implying a 'weak charge skin' where the surface region is relatively enriched in weak charges compared to (electromagnetic) charges. We extract the point neutron radius Rn = 5.751 ± 0.175 (exp) ± 0.026(model) ± 0.005(strange) fm, from RW. Here there is only a very small error (strange) from possible strange quark contributions. We find Rn to be slightly smaller than RW because of the nucleon's size. As a result, we find a neutron skin thickness of Rn-Rp = 0.302 ± 0.175 (exp) ± 0.026 (model) ± 0.005 (strange) fm, where Rp is the point proton radius.« less

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

    SciTech Connect

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

    2015-06-15

    We consider, for atoms from {sub 55}Cs to {sub 80}Hg, the effective atomic radius (r{sub ear}), 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 He{sub 2}. The values of r{sub ear} are about 50% larger than the mean radius of the outermost occupied orbital of 6s, . The value of r{sub ear} decreases from {sub 55}Cs to {sub 56}Ba and undergoes increases and decreases with rising nuclear charge from {sub 57}La to {sub 70}Y b. In fact r{sub ear} is understood as comprising two interlaced sequences; one consists of {sub 57}La, {sub 58}Ce, and {sub 64}Gd, which have electronic configuration (4f{sup n−1})(5d{sup 1})(6s{sup 2}), and the remaining atoms have configuration (4f{sup n})(6s{sup 2}). The sphere defined by r{sub ear} contains 85%–90% of the 6s electrons. From {sub 71}Lu to {sub 80}Hg the radius r{sub ear} also involves two sequences, corresponding to the two configurations 5d{sup n+1}6s{sup 1} and 5d{sup n}6s{sup 2}. The radius r{sub ear} according to the present methodology is considerably larger than r{sub vdW} obtained by other investigators, some of who have found values of r{sub vdW} close to .

  5. Effects of changes in convective efficiency on the solar radius and luminosity

    NASA Technical Reports Server (NTRS)

    Sweigart, A. V.

    1981-01-01

    A sequence of solar models has been constructed in order to investigate the sensitivity of the solar radius and luminosity to small changes in the ratio alpha of the mixing length lambda to the pressure-scale height Hp throughout the solar convective envelope. The basic procedure for determining this sensitivity was to impose a perturbation in alpha within the convective envelope and then to follow the resulting changes in the solar radius delta R and luminosity delta L for the next 10 to the 6th power yrs. These calculations gave the following results. (1) A perturbation in alpha produces immediate changes in the solar radius and luminosity. Initially delta L and delta alpha are related by delta L/L = 0.30 delta alpha/alpha. (2) The value of the ratio w = delta log R/delta log L is strongly time dependent. Its value just after the perturbation in alpha is 6.5 x 10 to the minus 4th power. (3) The ratio H = (delta log L) d delta log R/dt is much less time dependent and is a more suitable means for relating the changes in the solar radius and luminosity. (4) Both of these ratios imply that for any reasonable change in the solar luminosity the corresponding change in the solar radius is negligible.

  6. Space Inside a Liquid Sphere Transforms into De Sitter Space by Hilbert Radius

    NASA Astrophysics Data System (ADS)

    Rabounski, Dmitri; Borissova, Larissa

    2010-04-01

    Consider space inside a sphere of incompressible liquid, and space surrounding a mass-point. Metrics of the spaces were deduced in 1916 by Karl Schwarzschild. 1) Our calculation shows that a liquid sphere can be in the state of gravitational collapse (g00 = 0) only if its mass and radius are close to those of the Universe (M = 8.7x10^55 g, a = 1.3x10^28 cm). However if the same mass is presented as a mass-point, the radius of collapse rg (Hilbert radius) is many orders lesser: g00 = 0 realizes in a mass-point's space by other conditions. 2) We considered a liquid sphere whose radius meets, formally, the Hilbert radius of a mass-point bearing the same mass: a = rg, however the liquid sphere is not a collapser (see above). We show that in this case the metric of the liquid sphere's internal space can be represented as de Sitter's space metric, wherein λ = 3/a^2 > 0: physical vacuum (due to the λ-term) is the same as the field of an ideal liquid where ρ0 < 0 and p = -ρ0 c^2 > 0 (the mirror world liquid). The gravitational redshift inside the sphere is produced by the non-Newtonian force of repulsion (which is due to the λ-term, λ = 3/a^2 > 0); it is also calculated.

  7. High precision measurement of the proton charge radius: The PRad experiment

    SciTech Connect

    Meziane, Mehdi

    2013-11-01

    The recent high precision measurements of the proton charge radius performed at PSI from muonic hydrogen Lamb shift puzzled the hadronic physics community. A value of 0.8418 {+-} 0.0007 fm was extracted which is 7{sigma} smaller than the previous determinations obtained from electron-proton scattering experiments and based on precision spectroscopy of electronic hydrogen. An additional extraction of the proton charge radius from electron scattering at Mainz is also in good agreement with these "electronic" determinations. An independent measurement of the proton charge radius from unpolarized elastic ep scattering using a magnetic spectrometer free method was proposed and fully approved at Jefferson Laboratory in June 2012. This novel technique uses the high precision calorimeter HyCal and a windowless hydrogen gas target which makes possible the extraction of the charge radius at very forward angles and thus very low momentum transfer Q{sup 2} up to 10{sup -4} (GeV/c){sup 2} with an unprecedented sub-percent precision for this type of experiment. In this paper, after a review of the recent progress on the proton charge radius extraction and the new high precision experiment PRad will be presented.

  8. MEASURING THE SOLAR RADIUS FROM SPACE DURING THE 2012 VENUS TRANSIT

    SciTech Connect

    Emilio, M.; Couvidat, S.; Bush, R. I.; Kuhn, J. R.; Scholl, I. F. E-mail: kuhn@ifa.hawaii.edu E-mail: couvidat@stanford.edu

    2015-01-01

    We report in this work the determination of the solar radius from observations by the Helioseismic and Magnetic Imager (HMI) and the Atmospheric Imaging Assembly (AIA) instruments on board the Solar Dynamics Observatory during the 2012 June Venus transit of the Sun. Two different methods were utilized to determine the solar radius using images of Sun taken by the HMI instrument. The first technique fit the measured trajectory of Venus in front of the Sun for seven wavelengths across the Fe I absorption line at 6173 Å. The solar radius determined from this method varies with the measurement wavelength, reflecting the variation in the height of line formation. The second method measured the area of the Sun obscured by Venus to determine the transit duration from which the solar radius was derived. This analysis focused on measurements taken in the continuum wing of the line, and applied a correction for the instrumental point spread function (PSF) of the HMI images. Measurements taken in the continuum wing of the 6173 Å line, resulted in a derived solar radius at 1 AU of 959.''57 ± 0.''02 (695, 946 ± 15 km). The AIA instrument observed the Venus transit at ultraviolet wavelengths. Using the solar disk obscuration technique, similar to that applied to the HMI images, analysis of the AIA data resulted in values of R {sub ☉} = 963.''04 ± 0.''03 at 1600 Å and R {sub ☉} = 961.''76 ± 0.''03 at 1700 Å.

  9. The effect of adhesion on the contact radius in atomic force microscopy indentation.

    PubMed

    Sirghi, L; Rossi, F

    2009-09-01

    The effect of adhesion on nanoscale indentation experiments makes the interpretation of force-displacement curves acquired in these experiments very difficult. The indentation force results from the addition of adhesive and elastic forces at the indenter-sample contact. The evolution of the two forces during the indentation is determined by the variation of the indenter-sample contact radius. In the present work the variation of contact radius during atomic force microscopy (AFM) indentation of elastic and adhesive samples with conical indenters (AFM tips) is indirectly determined by measurements of the contact dynamic stiffness. For weak sample deformations, the contact radius is determined mainly by the adhesion force and indenter apex radius. For strong sample deformations, the contact radius increases linearly with the increase of the indenter displacement, the slope of this linear dependence being in agreement with Sneddon's theory of indentation (Sneddon 1965 Int. J. Eng. Sci. 3 47). Based on these results, a theoretical expression of indentation force dependence on displacement is found. This expression allows for determination of the thermodynamic work of adhesion at the indenter-sample interface and the sample elasticity modulus.

  10. High precision measurement of the proton charge radius: The PRad experiment

    SciTech Connect

    Meziane, Mehdi; Collaboration: PRad Collaboration

    2013-11-07

    The recent high precision measurements of the proton charge radius performed at PSI from muonic hydrogen Lamb shift puzzled the hadronic physics community. A value of 0.8418 ± 0.0007 fm was extracted which is 7σ smaller than the previous determinations obtained from electron-proton scattering experiments and based on precision spectroscopy of electronic hydrogen. An additional extraction of the proton charge radius from electron scattering at Mainz is also in good agreement with these 'electronic' determinations. An independent measurement of the proton charge radius from unpolarized elastic ep scattering using a magnetic spectrometer free method was proposed and fully approved at Jefferson Laboratory in June 2012. This novel technique uses the high precision calorimeter HyCal and a windowless hydrogen gas target which makes possible the extraction of the charge radius at very forward angles and thus very low momentum transfer Q{sup 2} up to 10{sup −4} (GeV/c){sup 2} with an unprecedented sub-percent precision for this type of experiment. In this paper, after a review of the recent progress on the proton charge radius extraction and the new high precision experiment PRad will be presented.

  11. Chemically etched modulation in wire radius for wire array Z-pinch perturbation studies

    SciTech Connect

    Jones, B.; Deeney, C.; McKenney, J.L.; Garrity, J.E.; Lobley, D.K.; Martin, K.L.; Griego, A.E.; Ramacciotti, J.P.; Bland, S.N.; Lebedev, S.V.; Bott, S.C.; Ampleford, D.J.; Palmer, J.B.A.; Rapley, J.; Hall, G.

    2004-11-01

    A technique for manufacturing wires with imposed modulation in radius with axial wavelengths as short as 1 mm is presented. Extruded aluminum 5056 with 15 {mu}m diameter was masked and chemically etched to reduce the radius by {approx}20% in selected regions. Characterized by scanning electron microscopy, the modulation in radius is a step function with a {approx}10 {mu}m wide conical transition between thick and thin segments, with some pitting in etched regions. Techniques for mounting and aligning these wires in arrays for fast z-pinch experiments will be discussed. Axially mass-modulated wire arrays of this type will allow the study of seeded Rayleigh-Taylor instabilities in z pinches, corona formation, wire initiation with varying current density in the wire core, and correlation of perturbations between adjacent wires. This tool will support magnetohydrodynamics code validation in complex three-dimensional geometries, and perhaps x-ray pulse shaping.

  12. En bloc joystick reduction of a comminuted intra-articular distal radius fracture: a technical trick.

    PubMed

    Siegall, Evan; Ziran, Bruce

    2014-08-01

    A patient with a 1-month-old intra-articular distal radius fracture (treated closed in a splint) presented with an unacceptable degree of pain and stiffness caused by shortening and dorsal angulation of the distal radius. The fracture was comminuted with 4 or 5 distinct fragments, several involving the articular surface. Surgical correction was attempted. During the procedure, it was noted that, though the distal radius was shortened and angulated, there was actually acceptable congruity of the articular surface itself, despite the intra-articular nature of the fracture. Bone quality was poor and healing incomplete. Thus, we were concerned the currently congruous articular surface would fall apart with manipulation. Given this situation, we used a unique scaffolding technique with Kirschner wires placed in perpendicular fashion to both hold the articular surface intact and manipulate it en bloc. This technique is a simple way to turn a complex fracture into an easily reduced 2-part fracture.

  13. The sup 11 Li neutron halo radius from pion double charge exchange

    SciTech Connect

    Hayes, A.C.

    1991-01-01

    We have analzed the pion double charge exchange data for the direct population of the ground state of {sup 11}Li by the {sup 11}B({pi}{sup {minus}}, {pi}{sup +}){sup 11}Li reaction and find that the measured cross section determines the rms radius of the last two neutrons in {sup 11}Li to be 5.1{sub {minus} 0.8}{sup +0.6} fm. It is shown that the pion cross-section falls off as the sixth power of the assumed neutron halo radius, so that a radius greater than about 6 fm is ruled out. Indeed, pion double charge is found to act as an unusually sensitive probe of the properties of this exotic neutron rich nucleus. 9 refs., 2 figs.

  14. Formula for the rms blur circle radius of Wolter telescope based on aberration theory

    NASA Technical Reports Server (NTRS)

    Shealy, David L.; Saha, Timo T.

    1990-01-01

    A formula for the rms blur circle for Wolter telescopes has been derived using the transverse ray aberration expressions of Saha (1985), Saha (1984), and Saha (1986). The resulting formula for the rms blur circle radius over an image plane and a formula for the surface of best focus based on third-, fifth-, and seventh-order aberration theory predict results in good agreement with exact ray tracing. It has also been shown that one of the two terms in the empirical formula of VanSpeybroeck and Chase (1972), for the rms blur circle radius of a Wolter I telescope can be justified by the aberration theory results. Numerical results are given comparing the rms blur radius and the surface of best focus vs the half-field angle computed by skew ray tracing and from analytical formulas for grazing incidence Wolter I-II telescopes and a normal incidence Cassegrain telescope.

  15. Efficiency Enhancement in a Tapered Free Electron Laser by Varying the Electron Beam Radius

    SciTech Connect

    Jiao, Yi; Wu, J.; Cai, Y.; Chao, A.W.; Fawley, W.M.; Frisch, J.; Huang, Z.; Nuhn, H.-D.; Pellegrini, C.; Reiche, S.; /PSI, Villigen

    2012-02-15

    Energy extraction efficiency of a free electron laser (FEL) can be increased when the undulator is tapered after the FEL saturation. By use of ray equation approximation to combine the one-dimensional FEL theory and optical guiding approach, an explicit physical model is built to provide insight to the mechanism of the electron-radiation coherent interaction with variable undulator parameters as well as electron beam radius. The contribution of variation in electron beam radius and related transverse effects are studied based on the presented model and numerical simulation. Taking a recent studied terawatt, 120 m long tapered FEL as an example, we demonstrate that a reasonably varied, instead of a constant, electron beam radius along the undulator helps to improve the optical guiding and thus the radiation output.

  16. Sagittal wrist motion of carpal bones following intraarticular fractures of the distal radius.

    PubMed

    Lutz, M; Rudisch, A; Kralinger, F; Smekal, V; Goebel, G; Gabl, M; Pechlaner, S

    2005-06-01

    Forty patients (mean age, 37 years) with intraarticular C2 and C3 Colles fractures were treated by open reduction, internal fixation and bone grafting. At a mean follow-up of 8 years radiocarpal and midcarpal motion was evaluated, the depth of the articular surface of the distal radius in the sagittal plane was measured and the presence of arthritis was noted. The fractures healed with a mean palmar tilt of 6 degrees , a mean ulnar tilt of 18 degrees and ulna variance within 1 mm of the contralateral side. The depth of the articular surface of the distal radius was 1.3 mm greater than the uninvolved side. Measurement of carpal bone angles relative to the radius in maximum flexion and extension revealed lunate extension of 23 degrees , lunate flexion of 15 degrees , capitate extension of 62 degrees , capitate flexion of 40 degrees . There was a significant correlation between articular surface depth and radiocarpal motion.

  17. Radius and chirality dependent conformation of polymer molecule at nanotube interface.

    PubMed

    Wei, Chenyu

    2006-08-01

    Temperature-dependent conformations of linear polymer molecules adsorbed at carbon nanotube (CNT) interfaces are investigated through molecule dynamics simulations. Model polyethylene (PE) molecules are shown to have selective conformations on the CNT surface, controlled by atomic structures of the CNT lattice and geometric coiling energy. PE molecules form entropy driven assembly domains, and their preferred wrapping angles around large radius CNT (40, 40) reflect the molecule configurations with energy minimums on a graphite plane. While PE molecules prefer 0 degrees wrapping on small radius armchair CNT (5, 5) predominantly at low temperatures, their configurations are shifted to larger wrapping angle ones on a similar radius zigzag CNT (10, 0). A nematic transformation around 280 K is identified through the Landau-de Gennes theory, with molecule aligning along tube axis in extended conformations.

  18. Reconstruction of Attritional Rupture of Flexor Tendons with Fascia Lata Graft Following Distal Radius Fracture Malunion.

    PubMed

    Bhat, A K; Acharya, A M; Soni, N

    2016-10-01

    Incidence of multiple flexor tendon rupture following distal radius fractures is rare with very few cases being reported in literature. We present an unusual case of a patient who had come to us with complaints of weakness and paresthesia of the right hand of one month prior and with a past history of dorsal plating for distal radius fracture nine years ago. Radiographs showed a distal radius fracture malunion with intact dorsal plate and protrusion of screws through the volar cortex. On exploration, attritional ruptures of all digital flexors were found with sparing of the Flexor Pollicis Longus tendon. The fibrous mass was excised and flexors reconstructed with a fascia lata graft. Attempt was made to correct the malunion with radial and ulnar osteotomies. At one year the patient had excellent restoration of digital flexion. PMID:27595963

  19. The binary Feige 24 - The mass, radius, and gravitational redshift of the DA white dwarf

    NASA Technical Reports Server (NTRS)

    Vennes, Stephane; Shipman, Harry L.; Thorstensen, John R.; Thejll, Peter

    1991-01-01

    Observations are reported which refine the binary ephemeris of the Feige 24 system, which contains a peculiar hot DA white dwarf and an M dwarf with an atmosphere illuminated by extreme ultraviolet radiation from the white dwarf. With the new ephemeris and a set of IUE high-dispersion spectra, showing phase-dependent redshifted C IV, N V, and Si IV resonance lines, the orbital velocity, and hence the mass (0.54 + or - 0.20 solar masses), and the gravitational redshift of the white dwarf (14.1 + or - 5.2 km/s) are determined independently. It is shown that the measured Einstein redshift is consistent with an estimated radius for the white dwarf obtained from a model atmosphere solid angle and a parallax measurement. This radius is twice the Hamada-Salpeter radius for the given mass and offers a prospect to investigate the presence of a massive hydrogen envelope in that white dwarf star.

  20. OSTEOTOMY OF THE DISTAL RADIUS USING A FIXED-ANGLE VOLAR PLATE

    PubMed Central

    de Oliveira, Ricardo Kaempf; Binz, Mário Arthur Rockenbach; Ferreira, Marco Tonding; Ruschel, Paulo Henrique; Serrano, Pedro Delgado; Praetzel, Rafael Pêgas

    2015-01-01

    Objective: Skewed consolidation of the distal radius, due to sequelae of fractures, may cause functional incapacity, thus leading such patients to present pain, loss of strength and diminished mobility. Based on the excellent results obtained from surgical treatment of unstable fractures of the distal radius through a volar approach and use of rigid fixation with a fixed-angle volar plate, we started to use the same method for osteotomy of the distal radius. Methods: A retrospective review was conducted, and 20 patients treated between February 2002 and October 2009 were found. The mean length of follow-up was 43.9 months (range: 12 to 96 months). The surgical indications were persistent pain, deformity and functional limitation subsequent to a dorsally displaced fracture. Results: The mean preoperative deformity was 27° of dorsal tilt of the distal radius, 87° of ulnar tilt, and 7.3 mm of shortening of the radius. All the osteotomies consolidated and the final mean volar tilt was 6.2°, with ulnar tilt of 69.3° and shortening of 1 mm. The mean mobility of the wrist increased by 19.9° (flexion) and by 24° (extension). Mean forearm supination increased by 23.5° and pronation by 21.7°. Grip strength increased from 13.4 to 34.5 pounds. Conclusion: Use of a fixed-angle volar plate for a volar approach towards osteotomy of the distal radius enables satisfactory correction of the deformities and eliminates the need for removal of the synthesis material caused by tendon complications PMID:27042618

  1. Radius evolution of sodium isotopes in mean-field and generator coordinate methods

    NASA Astrophysics Data System (ADS)

    Naulin, F.; Zhang, Jing-Ye; Flocard, H.; Vautherin, D.; Heenen, P. H.; Bonche, P.

    1998-06-01

    Radii of sodium isotopes have been calculated by using the Hartree-Fock-BCS model and the Generator Coordinate Method (GCM) with different forces. It is found that Hartree-Fock-BCS results present a jump in both neutron and proton radii from 22Na to 23Na. However, configuration mixing calculations performed with the GCM result in a smooth increase of the neutron radius and an almost constant proton radius for the sodium isotopes. We analyze and discuss our results in the light of recent experimental data.

  2. Acute Ulnar Shortening for Delayed Presentation of Distal Radius Growth Arrest in an Adolescent

    PubMed Central

    Ellanti, Prasad; Harrington, Paul

    2012-01-01

    Distal radius physeal fractures are common in children and adolescents. However, posttraumatic growth arrest is uncommon. The management of posttraumatic growth arrest is dependent on the severity of the deformity and the remaining growth potential of the patient. Various treatment options exist. We present a 17-year-old male with distal radius growth arrest who presented four years after the initial injury. He had a symptomatic 15 mm positive ulnar variance managed with an ulnar shortening osteotomy with the use of the AO mini distractor intraoperatively. To the best of our knowledge, an acute ulnar shortening of 15 mm is the largest reported. PMID:23227397

  3. An Examination of Proton Charge Radius Extractions from e–p Scattering Data

    SciTech Connect

    Arrington, John

    2015-09-15

    A detailed examination of issues associated with proton radius extractions from elastic electron–proton scattering experiments is presented. Sources of systematic uncertainty and model dependence in the extractions are discussed, with an emphasis on how these may impact the proton charge and magnetic radii. A comparison of recent Mainz data to previous world data is presented, highlighting the difference in treatment of systematic uncertainties as well as tension between different data sets. We find several issues that suggest that larger uncertainties than previously quoted may be appropriate, but do not find any corrections which would resolve the proton radius puzzle.

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

    DOE PAGES

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

    2014-10-01

    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. We find that 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.

  5. Skyrmion core size dependence as a function of the perpendicular anisotropy and radius in magnetic nanodots

    NASA Astrophysics Data System (ADS)

    Castro, M. A.; Allende, S.

    2016-11-01

    A detailed analytical and numerical analysis of the skyrmion core size dependence as a function of the uniaxial perpendicular anisotropy and radius in magnetic nanodots has been carried out. Results from micromagnetic calculations show a non-monotonic behavior between the skyrmion core size and the uniaxial perpendicular anisotropy. The increment of the radius reduces the skyrmion core size at constant uniaxial perpendicular anisotropy. Thus, these results can be used for the control of the core sizes in magnetic artificial skyrmion crystals or spintronic devices that need to use a skyrmion configuration at room temperature.

  6. Anomaly Mediation and Radius Stabilization by a Boundary Constant Superpotential in a Warped Space

    SciTech Connect

    Maru, Nobuhito; Sakai, Norisuke; Uekusa, Nobuhiro

    2008-11-23

    We present a very simple model of the radius stabilization in a supersymmetric (SUSY) Randall-Sundrum model with a hypermultiplet and a boundary constant superpotential. A wide range of parameters where the anomaly mediation of SUSY breaking is dominated is found although there are many problematic bulk effects of SUSY breaking. A negative cosmological constant in the radius stabilized vacuum can be cancelled by a localized SUSY breaking. Making use of this localized SUSY breaking also solves the {mu}-problem by Giudice-Masiero mechanism.

  7. Sensitivity of hyperfine structure to nuclear radius and quark mass variation

    SciTech Connect

    Dinh, T. H.; Dunning, A.; Dzuba, V. A.; Flambaum, V. V.

    2009-05-15

    To search for the temporal variation in the fundamental constants, one needs to know dependence of atomic transition frequencies on these constants. We study the dependence of the hyperfine structure of atomic s levels on nuclear radius and, via radius, on quark masses. An analytical formula has been derived and tested by the numerical relativistic Hartree-Fock calculations for Rb, Cd{sup +}, Cs, Yb{sup +}, and Hg{sup +}. The results of this work allow the use of the results of past and future atomic clock experiments and quasar spectra measurements to put constraints on time variation in the quark masses.

  8. Should muffin tin radius vary in different structures of a material?: A case study

    SciTech Connect

    Nayak, Vikas Banger, Suman Verma, U. P.

    2014-04-24

    Quantum mechanical calculations based on density functional theory and a generalized gradient approximation (GGA) have been used to study the structural properties of YbN. Its predicted unit cell lattice parameter in NaCl (B1) structure is 4.7810Å and in CsCl (B2) structure it is 2.8685Å. In the determination of lattice parameter the muffin tin radius (R{sub MT}) of constituent atoms play important role. In both the structures the muffin tin radius for Yb and N converges to 2.3 and 1.4 a.u., respectively.

  9. A Non-Interfering Beam Radius Diagnostic Suitable For Induction Linacs

    SciTech Connect

    Nexsen, W E

    2005-06-07

    High current electron induction linacs operate in a parameter regime that allows the use of a diamagnetic loop (DML) to measure the beam magnetic moment. Under certain easily met conditions the beam radius can be derived from the moment measurement. The DML has the advantage over the present methods of measuring beam radius in that it is an electrical measurement with good time resolution that does not interfere with the beam transport. I describe experiments on the LLNL accelerators, ETA-II and FXR that give confidence in the use of a DML as a beam diagnostic.

  10. Epidemiology and changed surgical treatment methods for fractures of the distal radius

    PubMed Central

    2013-01-01

    Background and purpose The incidence of fractures of the distal radius may have changed over the last decade, and operative treatment has been commoner during that time. We investigated the incidence of fractures of the distal radius and changing trends in surgical treatment during the period 2004–2010. Patients and methods Registry data on 42,583 patients with a fracture of the distal radius from 2004 to 2010 were evaluated regarding diagnosis, age, sex, and surgical treatment. Results The crude incidence rate was 31 per 104 person-years with a bimodal distribution. After the age of 45 years, the incidence rate in women increased rapidly and leveled off first at a very high age. The incidence rate in postmenopausal women was lower than previously reported. In men, the incidence was low and it increased slowly until the age of 80 years, when it amounted to 31 per 104 person-years. The number of surgical procedures increased by more than 40% despite the fact that there was reduced incidence during the study period. In patients ≥ 18 years of age, the proportion of fractures treated with plating increased from 16% to 70% while the use of external fixation decreased by about the same amount. Interpretation The incidence rate of distal radius fractures in postmenopausal women appears to have decreased over the last few decades. There has been a shift in surgical treatment from external fixation to open reduction and plating. PMID:23594225

  11. How to Measure the Radius of the Earth on Your Beach Vacation.

    ERIC Educational Resources Information Center

    Levine, Zachary H.

    1993-01-01

    Describes a method for determining the distance to the horizon which leads to determining the radius of the Earth. The article answers two interesting science questions: (1) Can you see the state of Kansas from Pike's Peak in Colorado? and (2) Can you see two sunsets in one day on the Keys of Florida? (MVL)

  12. Pearls and Pitfalls of the Volar Locking Plating for Distal Radius Fractures.

    PubMed

    Im, Jin-Hyung; Lee, Joo-Yup

    2016-06-01

    Volar locking plate fixation has been widely accepted method for the treatment of unstable distal radius fractures. Although the results of volar locking plate fixation are encouraging, it may cause implant-related complications such as flexor or extensor tendon injuries. In depth understanding of anatomy of the distal radius is mandatory in order to obtain adequate fixation of the fracture fragments and to avoid these complications. This article will review the anatomic characteristics of the distal radius because selecting proper implant and positioning of the plate is closely related to the volar surface anatomy of the distal radius. The number and the length of distal locking screws are also important to provide adequate fixation strength to maintain fracture fixation. We will discuss the pros and cons of the variable-angle locking plate, which was introduced in an effort to provide surgeons with more freedom for fixation. Finally, we will discuss about correcting radial length and volar tilt by using eccentric drill holes and distal locking first technique.

  13. Exposure of both the radius and ulna through a single posterior incision: a technical note.

    PubMed

    Wahsh, Abdel-Azim Hassan

    2015-01-01

    Fractures of both the radius and ulna are usually treated with two separate incisions and rarely with one single incision. However, both methods have disadvantages. For this we describe a relatively safe single straight posterior incision for exposure of the whole shafts of both the radius and ulna with the forearm rested on a board across the chest. This procedure was used in 116 forearms in 115 patients. The incision was in a straight line from the lateral humeral epicondyle to the ulnar head. The ulna was exposed between the extensor carpi ulnaris muscle and flexor digitorum profundus muscle covered by the aponeurosis of the flexor carpi ulnaris muscle and the radius between the extensor digitorum muscle and the extensor carpi radialis brevis muscle. During operation there was no difficulty in reducing or fixing any of the fractures in the whole shafts of the radius and ulna and at follow-up (average 5.2 years) there was no radioulnar synostosis or neurovascular injury in any of the forearms. PMID:27163077

  14. Friction in metal-on-metal total disc arthroplasty: effect of ball radius.

    PubMed

    Moghadas, Parshia; Mahomed, Aziza; Hukins, David W L; Shepherd, Duncan E T

    2012-02-01

    Total disc arthroplasty (TDA) can be used to replace a degenerated intervertebral disc in the spine. There are different designs of prosthetic discs, but one of the most common is a ball-and-socket combination. Contact between the bearing surfaces can result in high frictional torque, which can then result in wear and implant loosening. This study was designed to determine the effects of ball radius on friction. Generic models of metal-on-metal TDA were manufactured with ball radii of 10, 12, 14 and 16 mm, with a radial clearance of 0.015 mm. A simulator was used to test each sample in flexion-extension, lateral bending and axial rotation at frequencies of 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75 and 2 Hz under loads of 50, 600, 1200 and 2000 N, in new born calf serum. Frictional torque was measured and Stribeck curves were plotted to illustrate the lubrication regime in each case. It was observed that implants with a smaller ball radius showed lower friction and showed boundary and mixed lubrication regimes, whereas implants with larger ball radius showed boundary lubrication only. This study suggests designing metal-on-metal TDAs with ball radius of 10 or 12 mm, in order to reduce wear and implant loosening.

  15. Turnaround radius in an accelerated universe with quasi-local mass

    SciTech Connect

    Faraoni, Valerio; Lapierre-Léonard, Marianne; Prain, Angus E-mail: mlapierre12@ubishops.ca

    2015-10-01

    We apply the Hawking-Hayward quasi-local energy construct to obtain in a rigorous way the turnaround radius of cosmic structures in General Relativity. A splitting of this quasi-local mass into local and cosmological parts describes the interplay between local attraction and cosmological expansion.

  16. Laser differential confocal ultra-large radius measurement for convex spherical surface.

    PubMed

    Li, Zhigang; Qiu, Lirong; Zhao, Weiqian; Yang, Shuai

    2016-08-22

    A new laser differential confocal ultra-large radius measurement (LDCRM) method is proposed for high-precision measurement of ultra-large radii. Based on the property that the zero point of a differential confocal axial intensity curve precisely corresponds to the focus points of focusing beam, LDCRM measures the vertex positions of the test lens and the last optical surface of objective lens to obtain position difference L1, and then measures the vertex positions of the reflector and the last optical surface of objective lens to obtain the position difference L2, finally uses the measured L1 and L2 to calculate the radius of test lens. This method does not require the identification of confocal position. Preliminary experimental results and theoretical analyses indicate that the relative uncertainty is 0.03% for a convex spherical lens with a radius of approximately 20 m. LDCRM provides a novel approach for high-precision ultra-large radius measurement. PMID:27557251

  17. Observations of a probable change in the solar radius between 1715 and 1979.

    PubMed

    Dunham, D W; Sofia, S; Fiala, A D; Herald, D; Muller, P M

    1980-12-12

    Solar eclipses were observed from locations near both edges of the paths of totality in England in 1715, in Australia in 1976, and in North America in 1979. Analysis of these observations shows that the solar radius has contracted by 0.34 +/- 0.2 arc second in 264 years. PMID:17810770

  18. Management of Giant Cell Tumour Radius in a Three Year old Child with an Improvised Technique

    PubMed Central

    Puri, Ajay; Gulia, Ashish; Sharma, Seema; Verma, Amit K

    2014-01-01

    Giant cell tumours of immature skeleton have a very low incidence and epi-metaphyseal location. We are presenting giant cell tumour distal radius in a skeletally immature patient; an uncontained defect with a large soft tissue component which was managed by wide excision and reconstruction with an improvised technique. PMID:25654002

  19. Stability Radius as a Method for Comparing the Dynamics of Neuromechanical Systems

    PubMed Central

    Bingham, Jeffrey T.; Ting, Lena H.

    2015-01-01

    Robust motor behaviors emerge from neuromechanical interactions that are nonlinear, have delays, and contain redundant neural and biomechanical components. For example, in standing balance a subject’s muscle activity (neural control) decreases as stance width (biomechanics) increases when responding to a lateral perturbation, yet the center-of-mass motion (behavior) is nearly identical regardless of stance width. We present stability radius, a technique from robust control theory, to overcome the limitations of classical stability analysis tools, such as gain margin, which are insufficient for predicting how concurrent changes in both biomechanics (plant) and neural control (controller) affect system behavior. We first present the theory and then an application to a neuromechanical model of frontal-plane standing balance with delayed feedback. We show that stability radius can quantify differences in the sensitivity of system behavior to parameter changes, and predict that narrowing stance width increases system robustness. We further demonstrate that selecting combinations of stance width (biomechanics) and feedback gains (neural control) that have the same stability radius produce similar center-of-mass behavior in simulation. Therefore, stability radius may provide a useful tool for understanding neuromechanical interactions in movement and could aid in the design of devices and therapies for improving motor function. PMID:23744699

  20. Understanding the proton radius puzzle: Nuclear structure effects in light muonic atoms

    NASA Astrophysics Data System (ADS)

    Ji, Chen; Hernandez, Oscar Javier; Nevo Dinur, Nir; Bacca, Sonia; Barnea, Nir

    2016-03-01

    We present calculations of nuclear structure effects to the Lamb shift in light muonic atoms. We adopt a modern ab-initio approach by combining state-of-the-art nuclear potentials with the hyperspherical harmonics method. Our calculations are instrumental to the determination of nuclear charge radii in the Lamb shift measurements, which will shed light on the proton radius puzzle.

  1. A Spitzer Infrared Radius for the Transiting Extrasolar Planet HD 209458 b

    NASA Technical Reports Server (NTRS)

    Richardson, L. Jeremy; Harrington, Joseph; Seager, Sara; Deming, Drake

    2007-01-01

    We have measured the infrared transit of the extrasolar planet HD 209458 b using the Spitzer Space Telescope. We observed two primary eclipse events (one partial and one complete transit) using the 24 micrometer array of the Multiband Imaging Photometer for Spitzer (MIPS). We analyzed a total of 2392 individual images (10-second integrations) of the planetary system, recorded before, during, and after transit. We perform optimal photometry on the images and use the local zodiacal light as a short-term flux reference. At this long wavelength, the transit curve has a simple box-like shape, allowing robust solutions for the stellar and planetary radii independent of stellar limb darkening, which is negligible at 24 micrometers. We derive a stellar radius of R(sub *) = 1.06 plus or minus 0.07 solar radius, a planetary radius of R(sub p) = 1.26 plus or minus 0.08 R(sub J), and a stellar mass of 1.17 solar mass. Within the errors, our results agree with the measurements at visible wavelengths. The 24 micrometer radius of the planet therefore does not differ significantly compared to the visible result. We point out the potential for deriving extrasolar transiting planet radii to high accuracy using transit photometry at slightly shorter IR wavelengths where greater photometric precision is possible.

  2. Predictions of Crystal Structure Based on Radius Ratio: How Reliable Are They?

    ERIC Educational Resources Information Center

    Nathan, Lawrence C.

    1985-01-01

    Discussion of crystalline solids in undergraduate curricula often includes the use of radius ratio rules as a method for predicting which type of crystal structure is likely to be adopted by a given ionic compound. Examines this topic, establishing more definitive guidelines for the use and reliability of the rules. (JN)

  3. Finite Larmor radius assisted velocity shear stabilization of the interchange instability in magnetized plasmas

    SciTech Connect

    Ng Sheungwah; Hassam, A.B.

    2005-06-15

    Finite Larmor radius (FLR) effects, originally shown to stabilize magnetized plasma interchange modes at short wavelength, are shown to assist velocity shear stabilization of long wavelength interchanges. It is shown that the FLR effects result in stabilization with roughly the same efficacy as the stabilization from dissipative (resistive and viscous) effects found earlier.

  4. The magnetic Rayleigh-Taylor instability and flute waves at the ion Larmor radius scales

    SciTech Connect

    Onishchenko, O. G.; Pokhotelov, O. A.; Stenflo, L.; Shukla, P. K.

    2011-02-15

    The theory of flute waves (with arbitrary spatial scales compared to the ion Larmor radius) driven by the Rayleigh-Taylor instability (RTI) is developed. Both the kinetic and hydrodynamic models are considered. In this way we have extended the previous analysis of RTI carried out in the long wavelength limit. It is found that complete finite ion Larmor radius stabilization is absent when the ion diamagnetic velocity attains the ion gravitation drift velocity. The hydrodynamic approach allowed us to deduce a new set of nonlinear equations for flute waves with arbitrary spatial scales. It is shown that the previously deduced equations are inadequate when the wavelength becomes of the order of the ion Larmor radius. In the linear limit a Fourier transform of these equations yields the dispersion relation which in the so-called Pade approximation corresponds to the results of the fully kinetic treatment. The development of such a theory gives us enough grounds for an adequate description of the RTI stabilization by the finite ion Larmor radius effect.

  5. ROTATIONAL CORRECTIONS TO NEUTRON-STAR RADIUS MEASUREMENTS FROM THERMAL SPECTRA

    SciTech Connect

    Bauböck, Michi; Özel, Feryal; Psaltis, Dimitrios; Morsink, Sharon M.

    2015-01-20

    We calculate the rotational broadening in the observed thermal spectra of neutron stars spinning at moderate rates in the Hartle-Thorne approximation. These calculations accurately account for the effects of the second-order Doppler boosts as well as for the oblate shapes and the quadrupole moments of the neutron stars. We find that fitting the spectra and inferring the bolometric fluxes under the assumption that a star is not rotating causes an underestimate of the inferred fluxes and, thus, radii. The correction depends on the stellar spin, mass, radius, and the observer's inclination. For a 10 km, 1.4 M {sub ☉} neutron star spinning at 600 Hz, the rotational correction to the flux is ∼1%-4%, while for a 15 km neutron star with the same spin period, the correction ranges from 2% for pole-on sources to 12% for edge-on sources. We calculate the inclination-averaged corrections to inferred radii as a function of the neutron-star radius and mass and provide an empirical formula for the corrections. For realistic neutron-star parameters (1.4 M {sub ☉}, 12 km, 600 Hz), the stellar radius is on the order of 4% larger than the radius inferred under the assumption that the star is not spinning.

  6. Prebending of a titanium elastic intramedullary nail in the treatment of distal radius fractures in children.

    PubMed

    Cai, Haoqi; Wang, Zhigang; Cai, Haiqing

    2014-01-01

    The aims of this study were to introduce a method to treat distal radius diaphyseal metaphyseal junction fractures by prebending an elastic intramedullary nail and to evaluate the factors influencing fracture apposition. Fifty-two consecutive patients (4 to 15 years old) with a distal radius diaphyseal metaphyseal junction fracture were included. The nail was inserted and advanced into the proximal radial fragment as normal. After bending the nail distally about 90° at the site predetermined to lie at the distal segment, the elastic intramedullary nail was advanced until the prebent part completely entered the marrow cavity. The fracture angular deformity was fully corrected in anterior-posterior and lateral views. The apposition rate was 90% to 100% in lateral view, >50% in anterior-posterior view. The operation time was 16.73 ± 6.253 minutes. The average time of fracture healing was 5 months (range, 4-7 months). During 12 to 19 months of follow-up, firm fracture healing and good remodeling were observed, and there was no impaired forearm rotation function or secondary fracture. Our study showed the treatment of distal radius diaphyseal metaphyseal junction fractures by prebent intramedullary nail could make up for the deficiency of Kirschner wires and steel plates and keep the fracture stable. Fracture type and the anatomical features of the distal radius were associated with fracture apposition. PMID:24833151

  7. Estimating the Radius of the Convective Core of Main-sequence Stars from Observed Oscillation Frequencies

    NASA Astrophysics Data System (ADS)

    Yang, Wuming

    2016-10-01

    The determination of the size of the convective core of main-sequence stars is usually dependent on the construction of models of stars. Here we introduce a method to estimate the radius of the convective core of main-sequence stars with masses between about 1.1 and 1.5 M ⊙ from observed frequencies of low-degree p-modes. A formula is proposed to achieve the estimation. The values of the radius of the convective core of four known stars are successfully estimated by the formula. The radius of the convective core of KIC 9812850 estimated by the formula is 0.140 ± 0.028 R ⊙. In order to confirm this prediction, a grid of evolutionary models was computed. The value of the convective-core radius of the best-fit model of KIC 9812850 is 0.149 R ⊙, which is in good agreement with that estimated by the formula from observed frequencies. The formula aids in understanding the interior structure of stars directly from observed frequencies. The understanding is not dependent on the construction of models.

  8. Dorsal displacement of the ulnar nerve after a displaced distal radius fracture: case report.

    PubMed

    Sohal, Jennifer Kaur R; Chia, Benjamin; Catalano, Louis W

    2009-03-01

    We report on a patient in whom ulnar nerve palsy developed after a closed distal radius fracture due to displacement of the ulnar nerve dorsal to the ulnar styloid. After delayed exploration and decompression of the ulnar nerve, the patient had recovery of both motor and sensory function of the ulnar nerve.

  9. RADIUS: Research Archive on Disability in the United States. [CD-ROMs].

    ERIC Educational Resources Information Center

    Sociometrics Corp., Los Altos, CA.

    This Research Archive on Disability in the United States (RADIUS), a database on CD-ROM, contains 19 data sets on the prevalence, incidence, correlates, and consequences of disability in the United States. The 19 data sets are: (1) 1991 National Maternal and Infant Health Follow-Up Survey; (2) National Pediatric Trauma Registry, 1988-1994; (3)…

  10. The mass and radius evolution of globular clusters in tidal fields

    NASA Astrophysics Data System (ADS)

    Gieles, Mark

    We present a simple theory for the evolution of initially compact clusters in a tidal field. The fundamental ingredient of the model is that a cluster conducts a constant fraction of its own energy through the half-mass radius by two-body interactions every half-mass relaxation time. This energy is produced in a self-regulative way in the core by an (unspecified) energy source. We find that the half-mass radius increases during the first part (roughly half) of the evolution and decreases in the second half, while the escape rate is constant and set by the tidal field. We present evolutionary tracks and isochrones for clusters in terms of cluster half-mass density, cluster mass and galacto-centric radius. We find substantial agreement between model isochrones and Milky Way globular cluster parameters, which suggests that there is a balance between the flow of energy and the central energy production for almost all globular clusters. We also find that the majority of the globular clusters are still expanding towards their tidal radius. Finally, a fast code for cluster evolution is presented.

  11. Correction to the interfacial tension by curvature radius: differences between droplets and bubbles.

    PubMed

    Castellanos, Aly J; Toro-Mendoza, Jhoan; Garcia-Sucre, Maximo

    2009-04-30

    In this work we analyze the behavior of the interfacial tension with the curvature radius of the disperse phase. Following the Young-Laplace deduction of the equation relating the internal pressure with the curvature radius for a fluid confined by a spherical interface, we restate the Tolman approach [J. Chem. Phys. 1949, 108, 333] to obtain an analytical expression relating the interfacial tension with the radius. We have found small differences between our results and those of Tolman for the liquid/gas (droplets) case. However, important differences between liquid/gas (droplets) and gas/liquid (bubbles) dispersions were found. In particular, the decrease in the interfacial tension of bubbles may be expected to occur for much larger curvature radii than for the case of droplets when the curvature radius decreases. A simple relation between the Tolman's delta parameter and the interfacial width is also discussed. In our calculations we have considered dispersions of droplet of water in methane and bubbles of methane in water at T = 273.15 K.

  12. Estimate for the size of the compactification radius of a one extra dimension universe

    SciTech Connect

    Da Rosa, Felipe S; Pascoal, F; Oliveira, L F; Farina, C

    2008-01-01

    In this work, we use the Casimir effect to probe the existence of one extra dimension. We begin by evaluating the Casimir pressure between two plates in a M{sup 4} x S{sup 1} manifold, and then use an appropriate statistical analysis in order to compare the theoretical expression with a recent experimental data and set bounds for the compactification radius.

  13. Pearls and Pitfalls of the Volar Locking Plating for Distal Radius Fractures.

    PubMed

    Im, Jin-Hyung; Lee, Joo-Yup

    2016-06-01

    Volar locking plate fixation has been widely accepted method for the treatment of unstable distal radius fractures. Although the results of volar locking plate fixation are encouraging, it may cause implant-related complications such as flexor or extensor tendon injuries. In depth understanding of anatomy of the distal radius is mandatory in order to obtain adequate fixation of the fracture fragments and to avoid these complications. This article will review the anatomic characteristics of the distal radius because selecting proper implant and positioning of the plate is closely related to the volar surface anatomy of the distal radius. The number and the length of distal locking screws are also important to provide adequate fixation strength to maintain fracture fixation. We will discuss the pros and cons of the variable-angle locking plate, which was introduced in an effort to provide surgeons with more freedom for fixation. Finally, we will discuss about correcting radial length and volar tilt by using eccentric drill holes and distal locking first technique. PMID:27454625

  14. Superhumps in Cataclysmic Binaries. XXV. qcrit, ɛ(q), and Mass-Radius

    NASA Astrophysics Data System (ADS)

    Patterson, Joseph; Kemp, Jonathan; Harvey, David A.; Fried, Robert E.; Rea, Robert; Monard, Berto; Cook, Lewis M.; Skillman, David R.; Vanmunster, Tonny; Bolt, Greg; Armstrong, Eve; McCormick, Jennie; Krajci, Thomas; Jensen, Lasse; Gunn, Jerry; Butterworth, Neil; Foote, Jerry; Bos, Marc; Masi, Gianluca; Warhurst, Paul

    2005-11-01

    We report on successes and failures in searching for positive superhumps in cataclysmic variables, and show the superhumping fraction as a function of orbital period. Basically, all short-period system do, all long-period systems do not, and a 50% success rate is found at Porb=3.1+/-0.2 hr. We can use this to measure the critical mass ratio for the creation of superhumps. With a mass-radius relation appropriate for cataclysmic variables, and an assumed mean white-dwarf mass of 0.75 Msolar, we find a mass ratio qcrit=0.35+/-0.02. We also report superhump studies of several stars of independently known mass ratio: OU Vir, XZ Eri, UU Aqr, and KV UMa (=XTE J1118+480). The latter two are of special interest, because they represent the most extreme mass ratios for which accurate superhump measurements have been made. We use these to improve the ɛ(q) calibration, by which we can infer the elusive q from the easy-to-measure ɛ (the fractional period excess of Psuperhump over Porb). This relation allows mass and radius estimates for the secondary star in any cataclysmic variable (CV) showing superhumps. The consequent mass-radius law shows an apparent discontinuity in radius near 0.2 Msolar, as predicted by the disrupted magnetic braking model for the 2.1-2.7 hr period gap. This is effectively the ``empirical main sequence'' for CV secondaries.

  15. Influence of radius of cylinder HTS bulk on guidance force in a maglev vehicle system

    NASA Astrophysics Data System (ADS)

    Longcai, Zhang

    2014-07-01

    Bulk superconductors had great potential for various engineering applications, especially in a high-temperature superconducting (HTS) maglev vehicle system. In such a system, the HTS bulks were always exposed to AC external magnetic field, which was generated by the inhomogeneous surface magnetic field of the NdFeB guideway. In our previous work, it was observed that the guidance force of the YBCO bulk over the NdFeB guideway used in the HTS maglev vehicle system was decayed by the application of the AC external magnetic field. In this paper, we investigated the influence of the radius of the cylinder HTS bulk exposed to an AC magnetic field perturbation on the guidance force in the maglev vehicle system. From the results, it was found that the guidance force was stronger for the bulk with bigger radius and the guidance force decay rates of the bulks were approximately equal despite of the different radius in the maglev vehicle system. Therefore, in order to obtain higher guidance force in the maglev vehicle system, we could use the cylinder HTS bulks with the bigger radius.

  16. Adaptive evolution of a derived radius morphology in manakins (Aves, Pipridae) to support acrobatic display behavior.

    PubMed

    Friscia, Anthony; Sanin, Gloria D; Lindsay, Willow R; Day, Lainy B; Schlinger, Barney A; Tan, Josh; Fuxjager, Matthew J

    2016-06-01

    The morphology of the avian skeleton is often studied in the context of adaptations for powered flight. The effects of other evolutionary forces, such as sexual selection, on avian skeletal design are unclear, even though birds produce diverse behaviors that undoubtedly require a variety of osteological modifications. Here, we investigate this issue in a family of passerine birds called manakins (Pipridae), which have evolved physically unusual and elaborate courtship displays. We report that, in species within the genus Manacus, the shaft of the radius is heavily flattened and shows substantial solidification. Past work anecdotally notes this morphology and attributes it to the species' ability to hit their wings together above their heads to produce loud mechanical sonations. Our results show that this feature is unique to Manacus compared to the other species in our study, including a variety of taxa that produce other sonations through alternate wing mechanisms. At the same time, our data reveal striking similarities across species in total radius volume and solidification. Together, this suggests that supposedly adaptive alterations in radial morphology occur within a conserved framework of a set radius volume and solidness, which in turn is likely determined by natural selection. Further allometric analyses imply that the radius is less constrained by body size and the structural demands that underlie powered flight, compared to other forelimb bones that are mostly unmodified across taxa. These results are consistent with the idea that the radius is more susceptible to selective modification by sexual selection. Overall, this study provides some of the first insight into the osteological evolution of passerine birds, as well as the way in which opposing selective forces can shape skeletal design in these species. J. Morphol. 277:766-775, 2016. © 2016 Wiley Periodicals, Inc. PMID:27027525

  17. ULTRASOUND SIMULATION IN THE DISTAL RADIUS USING CLINICAL HIGH-RESOLUTION PERIPHERAL-CT IMAGES

    PubMed Central

    Floch, Vincent Le; McMahon, Donald J.; Luo, Gangming; Cohen, Adi; Kaufman, Jonathan J.; Shane, Elizabeth; Siffert, Robert S.

    2008-01-01

    The overall objective of this research is to develop an ultrasonic method for noninvasive assessment of the distal radius. The specific objective of this study was to examine the propagation of ultrasound through the distal radius and determine the relationships between bone mass and architecture and ultrasound parameters. Twenty-six high-resolution peripheral-CT clinical images were obtained from a set of subjects that were part of a larger study on secondary osteoporosis. A single midsection binary slice from each image was selected and used in the two-dimensional (2D) simulation of an ultrasound wave propagating from the anterior to the posterior surfaces of each radius. Mass and architectural parameters associated with each radius, including total (trabecular and cortical) bone mass, trabecular volume fraction, trabecular number and trabecular thickness were computed. Ultrasound parameters, including net time delay (NTD), broadband ultrasound attenuation (BUA) and ultrasound velocity (UV) were also evaluated. Significant correlations were found between NTD and total bone mass (R2 = 0.92, p < 0.001), BUA and trabecular number (R2 = 0.78, p < 0.01) and UV and trabecular bone volume fraction (R2 = 0.82, p < 0.01). There was only weak, statistically insignificant correlation (R2 < 0.14, p = 0.21) found between trabecular thickness and any of the ultrasound parameters. The study shows that ultrasound measurements are correlated with bone mass and architecture at the distal radius and, thus, ultrasound may prove useful as a method for noninvasive assessment of osteoporosis and fracture risk. PMID:18343017

  18. An accurate mass and radius measurement for an ultracool white dwarf

    NASA Astrophysics Data System (ADS)

    Parsons, S. G.; Gänsicke, B. T.; Marsh, T. R.; Bergeron, P.; Copperwheat, C. M.; Dhillon, V. S.; Bento, J.; Littlefair, S. P.; Schreiber, M. R.

    2012-11-01

    Studies of cool white dwarfs in the solar neighbourhood have placed a limit on the age of the Galactic disc of 8-9 billion years. However, determining their cooling ages requires the knowledge of their effective temperatures, masses, radii and atmospheric composition. So far, these parameters could only be inferred for a small number of ultracool white dwarfs for which an accurate distance is known, by fitting their spectral energy distributions in conjunction with a theoretical mass-radius relation. However, the mass-radius relation remains largely untested, and the derived cooling ages are hence model dependent. Here we report direct measurements of the mass and radius of an ultracool white dwarf in the double-lined eclipsing binary SDSS J013851.54-001621.6. We find MWD = 0.529 ± 0.010 M⊙ and RWD = 0.0131 ± 0.0003 R⊙. Our measurements are consistent with the mass-radius relation and we determine a robust cooling age of 9.5 billion years for the 3570 K white dwarf. We find that the mass and radius of the low-mass companion star, Msec = 0.132 ± 0.003 M⊙ and Rsec = 0.165 ± 0.001 R⊙, are in agreement with evolutionary models. We also find evidence that this >9.5 Gyr old M5 star is still active, far beyond the activity lifetime for a star of its spectral type. This is likely caused by the high tidally enforced rotation rate of the star. The companion star is close to filling its Roche lobe and the system will evolve into a cataclysmic variable in only 70 Myr. Our direct measurements demonstrate that this system can be used to calibrate ultracool white dwarf atmospheric models.

  19. Three-dimensional tool radius compensation for multi-axis peripheral milling

    NASA Astrophysics Data System (ADS)

    Chen, Youdong; Wang, Tianmiao

    2013-05-01

    Few function about 3D tool radius compensation is applied to generating executable motion control commands in the existing computer numerical control (CNC) systems. Once the tool radius is changed, especially in the case of tool size changing with tool wear in machining, a new NC program has to be recreated. A generic 3D tool radius compensation method for multi-axis peripheral milling in CNC systems is presented. The offset path is calculated by offsetting the tool path along the direction of the offset vector with a given distance. The offset vector is perpendicular to both the tangent vector of the tool path and the orientation vector of the tool axis relative to the workpiece. The orientation vector equations of the tool axis relative to the workpiece are obtained through homogeneous coordinate transformation matrix and forward kinematics of generalized kinematics model of multi-axis machine tools. To avoid cutting into the corner formed by the two adjacent tool paths, the coordinates of offset path at the intersection point have been calculated according to the transition type that is determined by the angle between the two tool path tangent vectors at the corner. Through the verification by the solid cutting simulation software VERICUT® with different tool radiuses on a table-tilting type five-axis machine tool, and by the real machining experiment of machining a soup spoon on a five-axis machine tool with the developed CNC system, the effectiveness of the proposed 3D tool radius compensation method is confirmed. The proposed compensation method can be suitable for all kinds of three- to five-axis machine tools as a general form.

  20. Constraining the initial conditions of globular clusters using their radius distribution

    NASA Astrophysics Data System (ADS)

    Alexander, Poul E. R.; Gieles, Mark

    2013-05-01

    Studies of extragalactic globular clusters (GCs) have shown that the peak size of the GC radius distribution (RD) depends only weakly on galactic environment. We model RDs of GC populations using a simple prescription for a Hubble time of relaxation-driven evolution of cluster mass and radius. We consider a power-law cluster initial mass function (CIMF) with and without an exponential truncation, and focus in particular on a flat and a steep CIMF (power-law indices of 0 and -2, respectively). For the initial half-mass radii at birth, we adopt either Roche volume (RV) filling conditions (`filling', meaning that the ratio of half-mass to Jacobi radius is approximately rh/rJ ≃ 0.15) or strongly RV under-filling conditions (`under-filling', implying that initially rh/rJ ≪ 0.15). Assuming a constant orbital velocity about the galaxy centre, we find for a steep CIMF that the typical half-light radius scales with the galactocentric radius RG as R{^{1/3}_G}. This weak scaling is consistent with observations, but this scenario has the (well-known) problem that too many low-mass clusters survive. A flat CIMF with `filling' initial conditions results in the correct MF at old ages, but with too many large (massive) clusters at large RG. An `under-filling' GC population with a flat CIMF also results in the correct MF, and can also successfully reproduce the shape of the RD, with a peak size that is (almost) independent of RG. In this case, the peak size depends (almost) only on the peak mass of the GC MF. The (near) universality of the GC RD is therefore because of the (near) universality of the CIMF. There are some extended GCs in the outer halo of the Milky Way that cannot be explained by this model.

  1. Determination of the optical thickness and effective particle radius of clouds from reflected solar radiation measurements. I - Theory

    NASA Technical Reports Server (NTRS)

    Nakajima, Teruyuki; King, Michael D.

    1990-01-01

    A method is presented for determining the optical thickness and effective particle radius of stratiform cloud layers from reflected solar radiation measurements. A detailed study is presented which shows that the cloud optical thickness (tau c) and effective particle radius (r/e/) of water clouds can be determined solely from reflection function measurements at 0.75 micron and 2.16 microns, provided tau c is not less than 4 and r(e) is not less than 6 microns. For optically thin clouds, the retrieval becomes ambiguous, resulting in two possible solutions for the effective radius and optical thickness. Adding a third channel near 1.65 micron does not improve the situation noticeably, whereas the addition of a channel near 3.70 microns reduces the ambiguity in deriving the effective radius. The effective radius determined by the above procedure corresponds to the droplet radius at some optical depth within the cloud layer.

  2. Radius of Curvature Measurement of Large Optics Using Interferometry and Laser Tracker

    NASA Technical Reports Server (NTRS)

    Hagopian, John; Connelly, Joseph

    2011-01-01

    The determination of radius of curvature (ROC) of optics typically uses either a phase measuring interferometer on an adjustable stage to determine the position of the ROC and the optics surface under test. Alternatively, a spherometer or a profilometer are used for this measurement. The difficulty of this approach is that for large optics, translation of the interferometer or optic under test is problematic because of the distance of translation required and the mass of the optic. Profilometry and spherometry are alternative techniques that can work, but require a profilometer or a measurement of subapertures of the optic. The proposed approach allows a measurement of the optic figure simultaneous with the full aperture radius of curvature.

  3. Slow axis collimation lens with variable curvature radius for semiconductor laser bars

    NASA Astrophysics Data System (ADS)

    Xiong, Ling-Ling; Cai, Lei; Zheng, Yan-Fang; Liu, Hui; Zhang, Pu; Nie, Zhi-Qiang; Liu, Xing-Sheng

    2016-03-01

    Based on Snell's law and the constant phase in the front of optical field, a design method of the slow axis collimation lens with variable curvature radius is proposed for semiconductor laser bars. Variable radius of the collimator is designed by the transmission angle, and it is demonstrated that the collimator has good beam collimation ability by material with low refractive index. Resorting to the design thought of finite element method, the surface of the collimator has been divided, and it is feasible to be fabricated. This method is applied as an example in collimation of a 976 nm semiconductor laser bar. 6 mrad divergence angle of collimated beam at slow axis is realized by the designed collimation lens with refraction index of 1.51.

  4. Cloud Liquid Water, Mean Droplet Radius and Number Density Measurements Using a Raman Lidar

    NASA Technical Reports Server (NTRS)

    Whiteman, David N.; Melfi, S. Harvey

    1999-01-01

    A new technique for measuring cloud liquid water, mean droplet radius and droplet number density is outlined. The technique is based on simultaneously measuring Raman and Mie scattering from cloud liquid droplets using a Raman lidar. Laboratory experiments on liquid micro-spheres have shown that the intensity of Raman scattering is proportional to the amount of liquid present in the spheres. This fact is used as a constraint on calculated Mie intensity assuming a gamma function particle size distribution. The resulting retrieval technique is shown to give stable solutions with no false minima. It is tested using Raman lidar data where the liquid water signal was seen as an enhancement to the water vapor signal. The general relationship of retrieved average radius and number density is consistent with traditional cloud physics models. Sensitivity to the assumed maximum cloud liquid water amount and the water vapor mixing ratio calibration are tested. Improvements to the technique are suggested.

  5. The effect of perturbations of convective energy transport on the luminosity and radius of the Sun

    NASA Technical Reports Server (NTRS)

    Endal, A. S.; Twigg, L. W.

    1982-01-01

    The response of solar models to perturbations of the efficiency of convective energy transport is studied for a number of cases. Such perturbations primarily effect the shallow superadiabatic layer of the convective envelope (at depth of approx. 1000 km below the photosphere). Independent of the details of the perturbation scheme, the resulting change in the solar radius is always very small compared to the change in luminosity. This appears to be true for any physical mechanism of solar variability which operates in the outer layers of the convection zone. Changes of the solar radius have been inferred from historical observations of solar eclipses. Considering the constraints on concurrent luminosity changes, this type of solar variability must be indicative of changes in the solar structure at substantial depths below the superadiabatic layer of the convective envelope.

  6. Cloud liquid water, mean droplet radius, and number density measurements using a Raman lidar

    SciTech Connect

    Whiteman, David N.; Melfi, S. Harvey

    1999-12-27

    A new technique for measuring cloud liquid water, mean droplet radius, and droplet number density is outlined. The technique is based on simultaneously measuring Raman and Mie scattering from cloud liquid droplets using a Raman lidar. Laboratory experiments on liquid microspheres have shown that the intensity of Raman scattering is proportional to the amount of liquid present in the spheres. This fact is used as a constraint on calculated Mie intensity assuming a gamma function particle size distribution. The resulting retrieval technique is shown to give stable solutions with no false minima. It is tested using Raman lidar data where the liquid water signal was seen as an enhancement to the water vapor signal. The general relationship of retrieved average radius and number density is consistent with traditional cloud physics models. Sensitivity to the assumed maximum cloud liquid water amount and the water vapor mixing ratio calibration are tested. Improvements to the technique are suggested. (c) 1999 American Geophysical Union.

  7. [Intra-articular fracture of the distal radius: results following osteosynthesis with a support plate].

    PubMed

    Ferguson, G A; Leutenegger, A; Mark, G; Breiter, H; Rüedi, T

    1989-01-01

    The treatment of comminuted intra-articular fractures of the distal radius often requires an operative fixation. Beside the recently recommended external fixator, the support plate fixation offers a helpful alternative to treatment. Between 1980 and 1986, 30 wrists in 29 patients with intra-articular fractures of the distal radius were stabilized with a buttress plate an the Kantonsspital Chur, Switzerland. The mean follow-up-time was 15 months. These follow-ups showed that the buttress plate in treatment of complicated intra-articular fractures allows a satisfactory reduction and stabilization with restoration of the articular congruity and the possibility for early active assisted motion. Buttress plate fixation still remains a demanding technique, which in complicated cases, should be reserved for the experienced surgeon. PMID:2500786

  8. Model independent extraction of the proton magnetic radius from electron scattering

    NASA Astrophysics Data System (ADS)

    Epstein, Zachary; Paz, Gil; Roy, Joydeep

    2014-10-01

    We combine constraints from analyticity with experimental electron-proton scattering data to determine the proton magnetic radius without model-dependent assumptions on the shape of the form factor. We also study the impact of including electron-neutron scattering data, and ππ→NN ¯ data. Using representative data sets we find for a cut of Q2≤0.5 GeV2, rMp=0.91-0.06+0.03±0.02 fm using just proton scattering data; rMp=0.87-0.05+0.04±0.01 fm adding neutron data; and rMp=0.87-0.02+0.02 fm adding ππ data. We also extract the neutron magnetic radius from these data sets obtaining rMn=0.89-0.03+0.03 fm from the combined proton, neutron, and ππ data.

  9. Estimating permeability using median pore-throat radius obtained from mercury intrusion porosimetry

    NASA Astrophysics Data System (ADS)

    Gao, Zhiye; Hu, Qinhong

    2013-04-01

    Mercury intrusion porosimetry (MIP) has been widely used to characterize the pore structure for various types of porous media. Several relationships between permeability and pore structure information (e.g., porosity and pore-size distribution) have been developed in the literature. This work is to introduce a new, and simpler, empirical equation to predict permeability by solely using the median pore-throat radius (r50), which is the pore-throat radius corresponding to 50% mercury saturation. The total of 18 samples used in this work have a wide range of permeability, from 10-6 to 103 mD, which makes the new equation more applicable. The predicted permeabilities by using the new equation are comparable with permeability values obtained from other measurement methods, as shown from ten samples with permeability data measured with nitrogen.

  10. Two-dimensional positive column structure in a discharge tube with radius discontinuity

    SciTech Connect

    Zobnin, A. V. Usachev, A. D.; Petrov, O. F.; Fortov, V. E.

    2014-11-15

    The low-pressure (40 and 90 Pa) low-current (4 and 10 mA) direct current discharge in a tube with a sharp change of its radius is studied both numerically and experimentally. A fully self-consistent hybrid numerical model of a two-dimensional non-uniform positive column in neon is developed using a nonlocal approach. The model combines kinetic simulation of the electrons (under two-terms approach) and fluid description of the neon ions and permits to calculate the distribution of all plasma parameters in the direct current discharges in the cameras with cylindrical geometry and radius discontinuity. The simulation results are compared with the measured 585.3 nm neon spectral line absolute intensities and excited 1s{sub 3} metastable neon atom number densities. Non-local electron kinetics in the transition region and formation of standing strata are discussed.

  11. The modulational instability in the extended Hasegawa-Mima equation with a finite Larmor radius

    SciTech Connect

    Gallagher, S.; Hnat, B.; Rowlands, G.; Connaughton, C.; Nazarenko, S.

    2012-12-15

    The effects of the finite Larmor radius on the generation of zonal flows by the four-wave modulational instability are investigated using an extended form of the Hasegawa-Mima equation. Growth rates of the zonal mode are quantified using analytical predictions from a four-mode truncated model, as well as from direct numerical simulation of the nonlinear extended Hasegawa-Mima equation. We not only consider purely zonal flows but also examine the generic oblique case and show that, for small Larmor radii, off-axis modes may become dominant. We find a key parameter M{sub {rho}} which characterises the behaviour of the system due to changes in the Larmor radius. We find that, similarly to previous results obtained by changing the driving wave amplitude, two separate dynamical regimes can be accessed. These correspond to oscillatory energy transfer between zonal flows and a driving wave and the fully saturated zonal flow.

  12. The modulational instability in the extended Hasegawa-Mima equation with a finite Larmor radius

    NASA Astrophysics Data System (ADS)

    Gallagher, S.; Hnat, B.; Connaughton, C.; Nazarenko, S.; Rowlands, G.

    2012-12-01

    The effects of the finite Larmor radius on the generation of zonal flows by the four-wave modulational instability are investigated using an extended form of the Hasegawa-Mima equation. Growth rates of the zonal mode are quantified using analytical predictions from a four-mode truncated model, as well as from direct numerical simulation of the nonlinear extended Hasegawa-Mima equation. We not only consider purely zonal flows but also examine the generic oblique case and show that, for small Larmor radii, off-axis modes may become dominant. We find a key parameter Mρ which characterises the behaviour of the system due to changes in the Larmor radius. We find that, similarly to previous results obtained by changing the driving wave amplitude, two separate dynamical regimes can be accessed. These correspond to oscillatory energy transfer between zonal flows and a driving wave and the fully saturated zonal flow.

  13. Analytical study of striated nozzle flow with small radius of curvature ratio throats

    NASA Technical Reports Server (NTRS)

    Norton, D. J.; White, R. E.

    1972-01-01

    An analytical method was developed which is capable of estimating the chamber and throat conditions in a nozzle with a low radius of curvature throat. The method was programmed using standard FORTRAN 4 language and includes chemical equilibrium calculation subprograms (modified NASA Lewis program CEC71) as an integral part. The method determines detailed and gross rocket characteristics in the presence of striated flows and gives detailed results for the motor chamber and throat plane with as many as 20 discrete zones. The method employs a simultaneous solution of the mass, momentum, and energy equations and allows propellant types, 0/F ratios, propellant distribution, nozzle geometry, and injection schemes to be varied so to predict spatial velocity, density, pressure, and other thermodynamic variable distributions in the chamber as well as the throat. Results for small radius of curvature have shown good comparison to experimental results. Both gaseous and liquid injection may be considered with frozen or equilibrium flow calculations.

  14. Throughput maximization of particle radius measurements through balancing size versus current of the electron probe.

    PubMed

    Van den Broek, W; Van Aert, S; Goos, P; Van Dyck, D

    2011-06-01

    In this paper we investigate which probe size maximizes the throughput when measuring the radius of nanoparticles in high angle annular dark field scanning transmission electron microscopy (HAADF STEM). The size and the corresponding current of the electron probe determine the precision of the estimate of a particle's radius. Maximizing throughput means that a maximum number of particles should be imaged within a given time frame, so that a prespecified precision is attained. We show that Bayesian statistical experimental design is a very useful approach to determine the optimal probe size using a certain amount of prior knowledge about the sample. The dependence of the optimal probe size on the detector geometry and the diameter, variability and atomic number of the particles is investigated. An expression for the optimal probe size in the absence of any kind of prior knowledge about the specimen is derived as well.

  15. The core mass-radius relation for giants - A new test of stellar evolution theory

    NASA Technical Reports Server (NTRS)

    Joss, P. C.; Rappaport, S.; Lewis, W.

    1987-01-01

    It is demonstrated here that the measurable properties of systems containing degenerate dwarfs can be used as a direct test of the core mass-radius relation for moderate-mass giants if the final stages of the loss of the envelope of the progenitor giant occurred via stable critical lobe overflow. This relation directly probes the internal structure of stars at a relatively advanced evolutionary state and is only modestly influenced by adjustable parameters. The measured properties of six binary systems, including such diverse systems as Sirius and Procyon and two millisecond pulsars, are utilized to derive constraints on the empirical core mass-radius relation, and the constraints are compared to the theoretical relation. The possibility that the final stages of envelope ejection of the giant progenitor of Sirius B occurred via critical lobe overflow in historical times is considered.

  16. Brodie's abscess following percutaneous fixation of distal radius fracture in a child.

    PubMed

    Rajakulendran, Karthig; Picardo, Natasha E; El-Daly, Ibraheim; Hussein, Rami

    2016-04-01

    We report the case of a Brodie's abscess presenting five and a half years following closed reduction and percutaneous pinning of a distal radius fracture. The index surgery was complicated by a pin site infection that was treated successfully with antibiotics. The patient represented with forearm pain years later, and radiological investigations revealed a Brodie's abscess in the distal radius at the site of the previous Kirschner wires. The Brodie's abscess was managed through surgical curettage and antibiotics. Staphylococcus aureus and diphtheroid organisms were cultured from the intraoperative specimens. A Brodie's abscess is a form of localised subacute osteomyelitis, which usually occurs in the metaphysis of long bones and can mimic malignancy. Previous trauma or surgery has been implicated as predisposing factors. We have only identified one previously reported case of Brodie's abscess following percutaneous pinning. Ours is the first reported case in an adolescent. The aim of this paper is to raise awareness of this rare complication and review the current literature.

  17. Is Single-Radius Design Better for Quadriceps Recovery in Total Knee Arthroplasty?

    PubMed Central

    Kim, Duk-Hyun; Kim, Dong-Kyoon; Lee, Sang-Hak; Bae, Dae-Kyung

    2015-01-01

    Purpose Although single-radius (SR) designs have a theoretical advantage in quadriceps recovery following total knee arthroplasty (TKA), there has been a paucity of objective evaluation studies. Materials and Methods One hundred and twenty minimally invasive TKAs were prospectively randomized by a single surgeon into 2 groups: SR design TKA group and multi-radius design TKA group. Quadriceps force and power were assessed using a dynamometer, and clinical data were investigated preoperatively and 6 weeks, 3 months, 6 months and 1 year postoperatively. Results There were no differences between two groups in quadriceps recovery and clinical results throughout the follow-up period. Furthermore, the proportion of patients whose postoperative quadriceps force and power reached preoperative level was similar in both groups. Conclusions Femoral component design itself would not significantly influence quadriceps recovery after TKA. PMID:26676282

  18. A miniaturized biconvex quartz-crystal microbalance with large-radius spherical thickness distribution

    SciTech Connect

    Li Li; Esashi, Masayoshi; Abe, Takashi

    2004-09-27

    A miniaturized biconvex quartz-crystal microbalance (QCM) with large-radius spherical thickness distribution was fabricated by reactive ion etching (RIE) and photoresist reflow with solvent vapor technology. A conventional polishing method could not manufacture the miniaturized, spherically convex shape, which is necessary to suppress a spurious mode and obtain a high Q factor. Not only can the large-radius spherical convex shape be achieved by this technology, but also miniaturization and batch fabrication. The Q factor of the fabricated QCM (80 000) is two times higher than that of the planar QCM, and the spurious mode around the fundamental vibration mode is suppressed very well. It also has superior resonant characteristic under the viscoelastic liquid.

  19. RADIUS DETERMINATION OF SOLAR-TYPE STARS USING ASTEROSEISMOLOGY: WHAT TO EXPECT FROM THE KEPLER MISSION

    SciTech Connect

    Stello, Dennis; Bruntt, Hans; Bedding, Timothy R.; Chaplin, William J.; Elsworth, Yvonne; Creevey, Orlagh L.; Jimenez-Reyes, Sebastian J.; Garcia-Hernandez, Antonio; Moya, Andres; Suarez, Juan-Carlos; Monteiro, Mario J. P. F. G.; Sousa, Sergio G.; Quirion, Pierre-Olivier; Arentoft, Torben; Christensen-Dalsgaard, Joergen; Appourchaux, Thierry; Ballot, Jerome; Fletcher, Stephen T.; Garcia, Rafael A.

    2009-08-01

    For distant stars, as observed by the NASA Kepler satellite, parallax information is currently of fairly low quality and is not complete. This limits the precision with which the absolute sizes of the stars and their potential transiting planets can be determined by traditional methods. Asteroseismology will be used to aid the radius determination of stars observed during NASA's Kepler mission. We report on the recent asteroFLAG hare-and-hounds Exercise no. 2, where a group of 'hares' simulated data of F-K main-sequence stars that a group of 'hounds' sought to analyze, aimed at determining the stellar radii. We investigated stars in the range 9 < V < 15, both with and without parallaxes. We further test different uncertainties in T {sub eff}, and compare results with and without using asteroseismic constraints. Based on the asteroseismic large frequency spacing, obtained from simulations of 4 yr time series data from the Kepler mission, we demonstrate that the stellar radii can be correctly and precisely determined, when combined with traditional stellar parameters from the Kepler Input Catalogue. The radii found by the various methods used by each independent hound generally agree with the true values of the artificial stars to within 3%, when the large frequency spacing is used. This is 5-10 times better than the results where seismology is not applied. These results give strong confidence that radius estimation can be performed to better than 3% for solar-like stars using automatic pipeline reduction. Even when the stellar distance and luminosity are unknown we can obtain the same level of agreement. Given the uncertainties used for this exercise we find that the input log g and parallax do not help to constrain the radius, and that T {sub eff} and metallicity are the only parameters we need in addition to the large frequency spacing. It is the uncertainty in the metallicity that dominates the uncertainty in the radius.

  20. High performance reversed shear plasmas with a large radius transport barrier in JT-60U

    NASA Astrophysics Data System (ADS)

    Fujita, T.; Hatae, T.; Oikawa, T.; Takeji, S.; Shirai, H.; Koide, Y.; Ishida, S.; Ide, S.; Ishii, Y.; Ozeki, T.; Higashijima, S.; Yoshino, R.; Kamada, Y.; Neyatani, Y.

    1998-02-01

    The operation of reversed shear plasmas in JT-60U has been extended to the low-q, high-Ip region keeping a large radius transport barrier, and a high fusion performance has been achieved. Record values of deuterium-tritium (DT)-equivalent power gain in JT-60U have been obtained: QDTeq = 1.05, τE = 0.97 s, nD(0) = 4.9 × 1019 m-3 and Ti(0) = 16.5 keV. A large improvement in confinement resulted from the formation of an internal transport barrier (ITB) with a large radius, which was characterized by steep gradients in electron density, electron temperature and ion temperature just inside the position of qmin. Large negative shear regions, up to 80% of the plasma minor radius in the low-qmin regime (qmin~2), were obtained by plasma current ramp-up after the formation of the ITB with the pressure and current profiles being controlled by adjustment of plasma volume and beam power. The ITB was established by on-axis beam heating into a low density target plasma with reversed shear that was formed by current ramp-up without beam heating. The confinement time increased with the radius of the ITB and the decrease of qmin at a fixed toroidal field. High H factors, up to 3.3, were achieved with an L mode edge. The effective one fluid thermal diffusivity χeff had its minimum in the ITB. The values of H/q95 and βt increased with the decrease of q95, and the highest performance was achieved at q95 ~3.1 (2.8 MA). The performance was limited by disruptive beta collapses with βN~2 at qmin~2.

  1. HZ Her: Stellar radius from X-ray eclipse observations, evolutionary state, and a new distance

    SciTech Connect

    Leahy, D. A.; Abdallah, M. H.

    2014-10-01

    Observations of HZ Her/Her X-1 by the Rossi X-Ray Timing Explorer (RXTE) covering high state eclipses of the neutron star are analyzed here. Models of the eclipse are used to measure the radius and atmospheric scale height of HZ Her, the stellar companion to the neutron star. The radius is 2.58-3.01 × 10{sup 11} cm, depending on system inclination and mass ratio (q), with an accuracy of ∼1 part in 1000 for given inclination and q. We fit Kurucz model stellar atmosphere models to archival optical observations. The resulting effective temperature (T {sub eff}) of the unheated face of HZ Her is determined to be in the 2σ range of 7720 K-7865 K, and metallicity (log (Z/Z {sub ☉})) in the range of –0.27 to +.03. The model atmosphere surface flux and new radius yield a new distance to HZ Her/Her X-1, depending on system inclination and q: a best-fit value of 6.1 kpc with upper and lower limits of 5.7 kpc and 7.0 kpc. We calculate stellar evolution models for the range of allowed masses (from orbital parameters) and allowed metallicities (from optical spectrum fits). The stellar models agree with T {sub eff} and the radius of HZ Her for two narrow ranges of mass: 2.15-2.20 M {sub ☉} and 2.35-2.45 M {sub ☉}. This lower mass range implies a low neutron star mass (1.3 M {sub ☉}), whereas the higher mass range implies a high neutron star mass (1.5-1.7 M {sub ☉}).

  2. Unitarity limits on the mass and radius of dark matter particles

    SciTech Connect

    Griest, K.; Kamionkowski, M.

    1989-09-01

    Using partial wave unitarity and the observed density of the Universe, it is show that a stable elementary particle which was once in thermal equilibrium cannot have a mass greater than 340 TeV. An extended object which was once in thermal equilibrium cannot have a radius less than 7.5 x 10(exp -7) fm. A lower limit to the relic abundance of such particles is also found.

  3. Unitarity limits on the mass and radius of dark-matter particles

    NASA Technical Reports Server (NTRS)

    Griest, Kim; Kamionkowski, Marc

    1990-01-01

    Using partial wave unitarity and the observed density of the Universe, it is shown that a stable elementary particle which was once in thermal equilibrium cannot have a mass greater than 340 TeV. An extended object which was once in thermal equlibrium cannot have a radius less than 7.5 x 10(exp -7) fm. A lower limit to the relic abundance of such particles is also found.

  4. Unitarity limits on the mass and radius of dark-matter particles

    SciTech Connect

    Griest, K. ); Kamionkowski, M. NASA/Fermilab Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, Illinois 60510-0500 )

    1990-02-05

    Using partial-wave unitarity and the observed density of the Universe, we show that a stable elementary particle which was once in thermal equilibrium cannot have a mass greater than 340 TeV. An extended object which was once in thermal equilibrium cannot have a radius less than 7.5{times}10{sup {minus}7} fm. A lower limit to the relic abundance of such particles is also found.

  5. [Fracture of the diaphyseal radius during Cyr wheel practice - an uncommon injury of wheel gymnastics].

    PubMed

    Kauther, M D; Rummel, S; Hussmann, B; Lendemans, S; Nast-Kolb, D; Wedemeyer, C

    2011-12-01

    The cyr wheel is a modified gymnastic wheel with only one ring that can lead to extreme forces on the gymnast. We report on a distal radius shaft fracture (AO 22 A 2.1) and a fracture of the styloid process of the ulna that occurred after holding on to a slipping Cyr wheel and exposition to high pressure on the lower arm. The fracture was fixed by screws and a plate. PMID:22161268

  6. Unitarity limits on the mass and radius of dark matter particles

    NASA Technical Reports Server (NTRS)

    Griest, Kim; Kamionkowski, Marc

    1989-01-01

    Using partial wave unitarity and the observed density of the Universe, it is show that a stable elementary particle which was once in thermal equilibrium cannot have a mass greater than 340 TeV. An extended object which was once in thermal equilibrium cannot have a radius less than 7.5 x 10(exp -7) fm. A lower limit to the relic abundance of such particles is also found.

  7. Analytical description of extension, torque and supercoiling radius of a stretched twisted DNA

    PubMed Central

    Neukirch, Sébastien; Marko, John F.

    2011-01-01

    We study the mixture of extended and supercoiled DNA that occurs in a twisted DNA molecule under tension. Closed-form asymptotic solutions for the supercoiling radius, extension and torque of the molecule are obtained in the high-force limit where electrostatic and elastic effects dominate. We demonstrate that experimental data obey the extension and torque scaling laws apparent in our formulae, in the regime where thermal fluctuation effects are quenched by applied force. PMID:21517425

  8. Is Bone Grafting Necessary in the Treatment of Malunited Distal Radius Fractures?

    PubMed Central

    Disseldorp, Dominique J. G.; Poeze, Martijn; Hannemann, Pascal F. W.; Brink, Peter R. G.

    2015-01-01

    Background Open wedge osteotomy with bone grafting and plate fixation is the standard procedure for the correction of malunited distal radius fractures. Bone grafts are used to increase structural stability and to enhance new bone formation. However, bone grafts are also associated with donor site morbidity, delayed union at bone–graft interfaces, size mismatch between graft and osteotomy defect, and additional operation time. Purpose The goal of this study was to assess bone healing and secondary fracture displacement in the treatment of malunited distal radius fractures without the use of bone grafting. Methods Between January 1993 and December 2013, 132 corrective osteotomies and plate fixations without bone grafting were performed for malunited distal radius fractures. The minimum follow-up time was 12 months. Primary study outcomes were time to complete bone healing and secondary fracture displacement. Preoperative and postoperative radiographs during follow-up were compared with each other, as well as with radiographs of the uninjured side. Results All 132 osteotomies healed. In two cases (1.5%), healing took more than 4 months, but reinterventions were not necessary. No cases of secondary fracture displacement or hardware failure were observed. Significant improvements in all radiographic parameters were shown after corrective osteotomy and plate fixation. Conclusion This study shows that bone grafts are not required for bone healing and prevention of secondary fracture displacement after corrective osteotomy and plate fixation of malunited distal radius fractures. Level of evidence Therapeutic, level IV, case series with no comparison group PMID:26261748

  9. Effect of workpiece edge angle on radius produced by vibratory finishing

    SciTech Connect

    Gillespie, L.K.

    1981-06-01

    An investigation was conducted to determine the effect of the included edge angle upon the radius produced by vibratory finishing of small precision parts. Workpiece materials studied included phosphor bronze, 6061-T6 aluminum, and 303Se stainless steel. Edges having included angles smaller than 90/sup 0/ require finishing cycles up to 20 times longer than those having angles greater than 90/sup 0/. The effect of the edge angle can be easily calculated.

  10. Radius Determination of Solar-type Stars Using Asteroseismology: What to Expect from the Kepler Mission

    NASA Astrophysics Data System (ADS)

    Stello, Dennis; Chaplin, William J.; Bruntt, Hans; Creevey, Orlagh L.; García-Hernández, Antonio; Monteiro, Mario J. P. F. G.; Moya, Andrés; Quirion, Pierre-Olivier; Sousa, Sergio G.; Suárez, Juan-Carlos; Appourchaux, Thierry; Arentoft, Torben; Ballot, Jerome; Bedding, Timothy R.; Christensen-Dalsgaard, Jørgen; Elsworth, Yvonne; Fletcher, Stephen T.; García, Rafael A.; Houdek, Günter; Jiménez-Reyes, Sebastian J.; Kjeldsen, Hans; New, Roger; Régulo, Clara; Salabert, David; Toutain, Thierry

    2009-08-01

    For distant stars, as observed by the NASA Kepler satellite, parallax information is currently of fairly low quality and is not complete. This limits the precision with which the absolute sizes of the stars and their potential transiting planets can be determined by traditional methods. Asteroseismology will be used to aid the radius determination of stars observed during NASA's Kepler mission. We report on the recent asteroFLAG hare-and-hounds Exercise#2, where a group of "hares" simulated data of F-K main-sequence stars that a group of "hounds" sought to analyze, aimed at determining the stellar radii. We investigated stars in the range 9 < V < 15, both with and without parallaxes. We further test different uncertainties in T eff, and compare results with and without using asteroseismic constraints. Based on the asteroseismic large frequency spacing, obtained from simulations of 4 yr time series data from the Kepler mission, we demonstrate that the stellar radii can be correctly and precisely determined, when combined with traditional stellar parameters from the Kepler Input Catalogue. The radii found by the various methods used by each independent hound generally agree with the true values of the artificial stars to within 3%, when the large frequency spacing is used. This is 5-10 times better than the results where seismology is not applied. These results give strong confidence that radius estimation can be performed to better than 3% for solar-like stars using automatic pipeline reduction. Even when the stellar distance and luminosity are unknown we can obtain the same level of agreement. Given the uncertainties used for this exercise we find that the input log g and parallax do not help to constrain the radius, and that T eff and metallicity are the only parameters we need in addition to the large frequency spacing. It is the uncertainty in the metallicity that dominates the uncertainty in the radius.

  11. The Impact of Patient Activity Level on Wrist Disability after Distal Radius Malunion in Older Adults

    PubMed Central

    Nelson, Gregory N.; Stepan, Jeffrey G.; Osei, Daniel A.; Calfee, Ryan P.

    2014-01-01

    Objective To determine if high-activity older adults are adversely affected by distal radius malunion. Design Cross-sectional study. Setting Hand clinics at a tertiary institution. Participants 96 patients ≥60 years old at time of fracture evaluated at least 1 year following distal radius fracture. Intervention Physical Activity Scale of the Elderly (PASE) scores stratified participants into high- and low-activity groups. Malunions were defined radiographically by change of ≥20° of lateral tilt, ≥15° radial inclination, ≥4 mm of ulnar variance, or ≥4 mm intra-articular gap or step-off, compared to the uninjured wrist. Main Outcome Measure Patient-rated disability of the upper-extremity was measured by the QuickDASH and Visual Analog Scales (VAS) for pain/function. Strength and motion measurements objectively quantified wrist function. Results High-activity participants with a distal radius malunion were compared to high-activity participants with well-aligned fractures. There was no significant difference in QuickDASH scores, VAS function, strength, and wrist motion despite statistically, but not clinically relevant, increases in VAS pain scores (difference 0.5, p=0.04) between the groups. Neither PASE score (β= 0.001, 95%CI: −0.002 to 0.004) nor malunion (β=0.133, 95%CI: −0.26 to 0.52) predicted QuickDASH scores in regression modeling after accounting for age, sex, and treatment. Operative management failed to improve outcomes and resulted in decreased grip strength (p=0.05) and more frequent complications (26% vs 7%, p=0.01) when compared to nonoperatively management. Conclusion Even among highly active older adults, distal radius malunion does not impact functional outcomes. Judicious use of operative management is warranted provided heightened complication rates. PMID:25233158

  12. Using a Video Camera to Measure the Radius of the Earth

    ERIC Educational Resources Information Center

    Carroll, Joshua; Hughes, Stephen

    2013-01-01

    A simple but accurate method for measuring the Earth's radius using a video camera is described. A video camera was used to capture a shadow rising up the wall of a tall building at sunset. A free program called ImageJ was used to measure the time it took the shadow to rise a known distance up the building. The time, distance and length of…

  13. Rupture of Flexor Pollicis Longus Tendon: A Complication of Volar Locking Plating of the Distal Radius.

    PubMed

    Rajeev, Aysha Sethunathan; Sreverthana, Shanaka; Harrison, John

    2010-08-01

    We report an unusual case of complete rupture of the flexor pollicis longus tendon following volar locking plating for a distal radius fracture. We believe that the prominence of a distal locking screw head predisposed to the rupture of the tendon. We highlight that correctly attaching the distal locking screws to the plate is essential for obtaining the correct biomechanics of the device and preventing flexor tendon rupture.

  14. [New minimally invasive approach for palmar plating in distal radius fractures].

    PubMed

    Chmielnicki, M; Prokop, A

    2015-02-01

    Distal radius fractures are among the most common fractures. Types A3 and C2 make up almost half of these. Volar fixed-angle plate fixation is the gold standard of treatment today. We wanted to minimise the approach to the distal radius through a transverse 2-3 cm incision in the wrist flexor fold, tunnelling beneath the pronator muscle. The operative technique is demonstrated here. 11 patients, averaging 70 years of age, underwent surgery for 7 A3 and 4 C2 type fractures. Average operating time was 50 minutes. Length of admission averaged 2.9 days. Using a visual analogue scale, pain decreased from 6/10 preoperatively to 3/10 on post-op day one and 2/10 on post-op day three. After 6 weeks, flexion and extension averaged 45-0-45°, and radial and ulnar deviation 20-0-20°. Pronation and supination averaged 85-0-85°. Grip strength with manometer averaged 90 % compared to the contralateral side at 6 weeks and 96 % at 3 months. As comparison, from 1 January 2008 until 31 May 2013, we treated 908 patients with distal radius fractures with volar fixed-angle plates through a conventional longitudinal incision of 5-8 cm. The average skin to skin time was 46 minutes, with an average length of admission of 5.6 days. A minimally invasive approach to treat distal radius fractures with volar plate fixation and sparing of the pronator muscle is possible. The initial patients treated with this approach experienced minimal post-operative pain, shorter hospital admissions, and rapid grip strength recovery with almost undisturbed rotational motion.

  15. Bone density of the radius, spine, and proximal femur in osteoporosis

    SciTech Connect

    Mazess, R.B.; Barden, H.; Ettinger, M.; Schultz, E.

    1988-02-01

    Bone mineral density (BMD) was measured in 140 normal young women (aged 20 to 39 years) and in 423 consecutive women over age 40 referred for evaluation of osteoporosis. Lumbar spine and proximal femur BMD was measured using dual-photon absorptiometry (/sup 153/Gd), whereas the radius shaft measurement used single-photon absorptiometry (/sup 125/I). There were 324 older women with no fractures, of which 278 aged 60 to 80 years served as age-matched controls. There were 99 women with fractures including 32 with vertebral and 22 with hip fractures. Subsequently, another 25 women with hip fractures had BMD measured in another laboratory; their mean BMD was within 2% of that of the original series. The mean age in both the nonfracture and fracture groups was 70 +/- 5 years. The BMD in the age-matched controls was 20% to 25% below that of normal young women for the radius, spine, and femur, but the Ward's triangle region of the femur showed even greater loss (35%). The mean BMD at all sites in the crush fracture cases was about 10% to 15% below that of age-matched controls. Spinal abnormality was best discriminated by spine and femoral measurements (Z score about 0.9). In women with hip fractures, the BMD was 10% below that of age-matched controls for the radius and the spine, and the BMD for the femoral sites was about 25% to 30% below that of age-matched control (Z score about 1.6). Femoral densities gave the best discrimination of hip fracture cases and even reflected spinal osteopenia. In contrast, neither the spine nor the radius reflected the full extent of femoral osteopenia in hip fracture.

  16. Adaptive optics for resolution/throughput optimization; variable-radius-mirror application for a PGM

    NASA Astrophysics Data System (ADS)

    Morikawa, Eizi; Scott, John D.; Saile, Volker

    1992-08-01

    The utilization of a bendable, variable-radius mirror as a key optical element to control resolution (and throughput) of an XUV monochromator is discussed. A bendable mirror is placed between source and grating; by bending it to either a concave or a convex figure along the dispersion direction, a variation of monochromator resolution is accomplished. As an application example, a plane-grating soft X-ray monochromator equipped with this bendable mirror system was investigated with ray-tracing calculations.

  17. Study on singular radius and surface boundary constraint in refractive beam shaper design

    SciTech Connect

    Liu, C.; Zhang, Shukui

    2007-10-01

    Abstract: This paper presents analysis on important issues associated with the design of the refractive laser beam shaping system. The concept of â singular radiusâ is introduced along with solutions to minimize its adverse effect on the shaper performance. In addition, the surface boundary constraint is also discussed in details. This study provides useful guidelines against possible general design errors that would degrade the shaper quality or add undesired complication to the system.

  18. The Impact of Surface Temperature Inhomogeneities on Quiescent Neutron Star Radius Measurements

    NASA Astrophysics Data System (ADS)

    Elshamouty, K. G.; Heinke, C. O.; Morsink, S. M.; Bogdanov, S.; Stevens, A. L.

    2016-08-01

    Fitting the thermal X-ray spectra of neutron stars (NSs) in quiescent X-ray binaries can constrain the masses and radii of NSs. The effect of undetected hot spots on the spectrum, and thus on the inferred NS mass and radius, has not yet been explored for appropriate atmospheres and spectra. A hot spot would harden the observed spectrum, so that spectral modeling tends to infer radii that are too small. However, a hot spot may also produce detectable pulsations. We simulated the effects of a hot spot on the pulsed fraction and spectrum of the quiescent NSs X5 and X7 in the globular cluster 47 Tucanae, using appropriate spectra and beaming for hydrogen atmosphere models, incorporating special and general relativistic effects, and sampling a range of system angles. We searched for pulsations in archival Chandra HRC-S observations of X5 and X7, placing 90% confidence upper limits on their pulsed fractions below 16%. We use these pulsation limits to constrain the temperature differential of any hot spots, and to then constrain the effects of possible hot spots on the X-ray spectrum and the inferred radius from spectral fitting. We find that hot spots below our pulsation limit could bias the spectroscopically inferred radius downward by up to 28%. For Cen X-4 (which has deeper published pulsation searches), an undetected hot spot could bias its inferred radius downward by up to 10%. Improving constraints on pulsations from quiescent LMXBs may be essential for progress in constraining their radii.

  19. Inter- and intra-observer agreement of the AO classification for operatively treated distal radius fractures.

    PubMed

    van Buijtenen, Jesse M; van Tunen, Mischa L C; Zuidema, Wietse P; Heilbron, Emile A; de Haan, Jeroen; de Vet, Henrica C W; Derksen, Robert J

    2015-11-01

    The reproducibility of the AO classification for distal radius fractures remains a topic of debate. Previous studies showed variable reproducibility results. Important treatment decisions depend on correct classification, especially in comminuted, intra-articular fractures. Therefore, reliable reproducibility results need to be undisputedly determined. Hence, the study objective was to assess inter- and intra-observer agreement of the AO classification for operatively treated distal radius fractures. A database of 54 radiographs of all AO types (A, B and C) and groups (A2-3, B1-3, and C1-3) of distal radius fractures was assessed in twofold. Likewise, a subset of 152 radiographs of solely C-type groups (C1-3) was assessed. All fractures were classified by six observers with different experience levels: three consultant trauma surgeons, one sixth-year trauma surgery resident, a consultant trauma radiologist, and an intern with limited experienced. The inter-observer agreement of both main types and groups was moderate (κ = 0.49 resp. κ = 0.48) in combination with a good intra-observer agreement (κ = 0.68 resp. κ = 0.70). The inter-observer agreement of the subset C-type fractures group was fair (κ = 0.27) with moderate intra-observer agreement (κ = 0.43). According to these results, the reproducibility of the AO classification of main types and groups of distal radius fractures based on conventional radiographs is insufficient (κ < 0.50), especially at group level of C-type fractures. PMID:26614083

  20. A lower radius and mass for the transiting extrasolar planet HAT-P-8 b

    NASA Astrophysics Data System (ADS)

    Mancini, L.; Southworth, J.; Ciceri, S.; Fortney, J. J.; Morley, C. V.; Dittmann, J. A.; Tregloan-Reed, J.; Bruni, I.; Barbieri, M.; Evans, D. F.; D'Ago, G.; Nikolov, N.; Henning, Th.

    2013-03-01

    Context. The extrasolar planet HAT-P-8 b was thought to be one of the more inflated transiting hot Jupiters. Aims: By using new and existing photometric data, we computed precise estimates of the physical properties of the system. Methods: We present photometric observations comprising eleven light curves covering six transit events, obtained using five medium-class telescopes and telescope-defocussing technique. One transit was simultaneously obtained through four optical filters, and two transits were followed contemporaneously from two observatories. We modelled these and seven published datasets using the jktebop code. The physical parameters of the system were obtained from these results and from published spectroscopic measurements. In addition, we investigated the theoretically-predicted variation of the apparent planetary radius as a function of wavelength, covering the range 330-960 nm. Results: We find that HAT-P-8 b has a significantly lower radius (1.321 ± 0.037 RJup) and mass (1.275 ± 0.053 MJup) compared to previous estimates (1.50-0.06+0.08 R_{Jup} and 1.52-0.16+0.18 M_{Jup} respectively). We also detect a radius variation in the optical bands that, when compared with synthetic spectra of the planet, may indicate the presence of a strong optical absorber, perhaps TiO and VO gases, near the terminator of HAT-P-8 b. Conclusions: These new results imply that HAT-P-8 b is not significantly inflated, and that its position in the planetary mass-radius diagram is congruent with those of many other transiting extrasolar planets. Full Table 2 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/551/A11

  1. DISCOVERY AND ATMOSPHERIC CHARACTERIZATION OF GIANT PLANET KEPLER-12b: AN INFLATED RADIUS OUTLIER

    SciTech Connect

    Fortney, Jonathan J.; Nutzman, Philip; Demory, Brice-Olivier; Desert, Jean-Michel; Buchhave, Lars A.; Charbonneau, David; Fressin, Francois; Rowe, Jason; Caldwell, Douglas A.; Jenkins, Jon M.; Ciardi, David; Gautier, Thomas N.; Bryson, Stephen T.; Howell, Steve B.; Everett, Mark; and others

    2011-11-01

    We report the discovery of planet Kepler-12b (KOI-20), which at 1.695 {+-} 0.030 R{sub J} is among the handful of planets with super-inflated radii above 1.65 R{sub J}. Orbiting its slightly evolved G0 host with a 4.438 day period, this 0.431 {+-} 0.041 M{sub J} planet is the least irradiated within this largest-planet-radius group, which has important implications for planetary physics. The planet's inflated radius and low mass lead to a very low density of 0.111 {+-} 0.010 g cm{sup -3}. We detect the occultation of the planet at a significance of 3.7{sigma} in the Kepler bandpass. This yields a geometric albedo of 0.14 {+-} 0.04; the planetary flux is due to a combination of scattered light and emitted thermal flux. We use multiple observations with Warm Spitzer to detect the occultation at 7{sigma} and 4{sigma} in the 3.6 and 4.5 {mu}m bandpasses, respectively. The occultation photometry timing is consistent with a circular orbit at e < 0.01 (1{sigma}) and e < 0.09 (3{sigma}). The occultation detections across the three bands favor an atmospheric model with no dayside temperature inversion. The Kepler occultation detection provides significant leverage, but conclusions regarding temperature structure are preliminary, given our ignorance of opacity sources at optical wavelengths in hot Jupiter atmospheres. If Kepler-12b and HD 209458b, which intercept similar incident stellar fluxes, have the same heavy-element masses, the interior energy source needed to explain the large radius of Kepler-12b is three times larger than that of HD 209458b. This may suggest that more than one radius-inflation mechanism is at work for Kepler-12b or that it is less heavy-element rich than other transiting planets.

  2. Measuring the neutron star radius to constrain the dense-matter equation of state.

    NASA Astrophysics Data System (ADS)

    Guillot, Sebastien; Servillat, Mathieu; Webb, Natalie; Rutledge, Robert E.

    2014-08-01

    A physical understanding of the behaviour of cold ultra-dense matter - at and above nuclear density - can only be achieved by the study of neutron stars, and the thermal emission from quiescent low-mass X-ray binaries inside globular clusters have proven very useful for that purpose. The recent ~2M⊙ mass measurements suggest that strange quark matter and hyperons/kaons condensate equations of states (EoS) are disfavoured, in favour of hadronic "normal matter" EoSs. Over much of the neutron star mass-radius parameter space, "normal matter" EoSs produce lines of quasi-constant radii (within the measurement uncertainties, of 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. 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 un-modelled spectrally hard components. Our results suggest a neutron star radius much smaller than previously reported, with a value RNS = 9.1±1.4 km, at 90% confidence, using conservative assumptions, which suggests that neutron star matter is best described by the softest "normal matter" equations of state.

  3. Prediction and Assessment of Reynolds Number Sensitivities Associated with Wing Leading-Edge Radius Variations

    NASA Technical Reports Server (NTRS)

    Wahls, Richard A.; Rivers, Melissa B.; Owens, Lewis R., Jr.

    1999-01-01

    The primary objectives of this study were to expand the data base showing the effects of LE radius distribution and corresponding sensitivity to Rn at subsonic and transonic conditions, and to assess the predictive capability of CFD for these effects. Several key elements led to the initiation of this project: 1) the necessity of meeting multipoint design requirements to enable a viable HSCT, 2) the demonstration that blunt supersonic leading-edges can be associated with performance gain at supersonic speeds , and 3) limited data. A test of a modified Reference H model with the TCA planform and 2 LE radius distributions was performed in the NTF, in addition to Navier-Stokes analysis for an additional 3 LE radius distributions. Results indicate that there is a tremendous potential to improve high-lift performance through the use of a blunt LE across the span given an integrated, fully optimized design, and that low Rn data alone is probably not sufficient to demonstrate the benefit.

  4. Prediction and Assessment of Reynolds Number Sensitivities Associated with Wing Leading-Edge Radius Variations

    NASA Technical Reports Server (NTRS)

    Wahls, Richard A.; Rivers, Melissa B.; Owen, Lewis R., Jr.

    1999-01-01

    The primary objectives of this study were to expand the data base showing the effects of LE radius distribution and corresponding . sensitivity to Rn at subsonic and transonic conditions, and to assess the predictive capability of CFD for these effects. Several key elements led to the initiation of this project: 1) the necessity of meeting multipoint design requirements to enable a viable HSCT, 2) the demonstration that blunt supersonic leading-edges can be associated with performance gain at supersonic speeds , and 3) limited data. A test of a modified Reference H model with the TCA planform and 2 LE radius distributions was performed in the NTF, in addition to Navier-Stokes analysis for an additional 3 LE radius distributions. Results indicate that there is a tremendous potential to improve high-lift performance through the use of a blunt LE across the span given an integrated, fully optimized design, and that low Rn data alone is probably not sufficient to demonstrate the benefit.

  5. Argon gas-puff radius optimiaztion for Saturn operating in the long-pulse mode.

    SciTech Connect

    Apruzese, John P.; Jackson, S. L.; Commisso, Robert J.; Weber, Bruce V.; Mosher, Daniel A.

    2010-06-01

    Argon gas puff experiments using the long pulse mode of Saturn (230-ns rise time) have promise to increase the coupled energy and simplify operations because the voltage is reduced in vacuum and the forward-going energy is higher for the same Marx charge. The issue addressed in this work is to determine if the 12-cm-diameter triple nozzle used in Saturn long-pulse-mode experiments to date provides maximum K-shell yield, or if a different-radius nozzle provides additional radiation. Long-pulse implosions are modeled by starting with measured density distributions from the existing 12-cm-diameter nozzle, and then varying the outer radius in an implosion-energy-conserving self-similar manner to predict the gas-puff diameter that results in the maximum K-shell yield. The snowplow-implosions and multi-zone radiation transport models used in the analysis are benchmarked against detailed measurements from the 12-cm-diameter experiments. These calculations indicate that the maximum K-shell emission is produced with very nearly the existing nozzle radius.

  6. Flory radius of polymers in a periodic field: an exact analytic theory.

    PubMed

    Chervanyov, A I; Heinrich, G

    2007-11-01

    We found an exact expression for the Flory radius R (F) of Gaussian polymers placed in an external periodic field. This solution is expressed in terms of the two parameters eta and a that describe the reduced strength of an external field and the period of the field to the polymer gyration radius ratio, respectively. R (F) is found to be a decaying function of eta for any values of a . Provided that the gyration radius is of the order of the period of an external field or less, the ground-state (GS) approximation of the exact result for R (F) is shown to give qualitatively incorrect results. In addition to the "ground-state" contribution, the exact solution for R (F) contains an additional term that is overlooked by the GS approximation. This term gives rise to the fact that R (F) as a function of eta exhibits power law behavior (rather than exponential decay obtained from the GS result) once eta exceeds the threshold value eta(con) .

  7. Determination of recombination radius in Si for binary collision approximation codes

    SciTech Connect

    Vizkelethy, Gyorgy; Foiles, Stephen M.

    2015-09-11

    Displacement damage caused by ions or neutrons in microelectronic devices can have significant effect on the performance of these devices. Therefore, it is important to predict not only the displacement damage profile, but also its magnitude precisely. Analytical methods and binary collision approximation codes working with amorphous targets use the concept of displacement energy, the energy that a lattice atom has to receive to create a permanent replacement. It was found that this “displacement energy” is direction dependent; it can range from 12 to 32 eV in silicon. Obviously, this model fails in BCA codes that work with crystalline targets, such as Marlowe. Marlowe does not use displacement energy; instead, it uses lattice binding energy only and then pairs the interstitial atoms with vacancies. Then based on the configuration of the Frenkel pairs it classifies them as close, near, or distant pairs, and considers the distant pairs the permanent replacements. Unfortunately, this separation is an ad hoc assumption, and the results do not agree with molecular dynamics calculations. After irradiation, there is a prompt recombination of interstitials and vacancies if they are nearby, within a recombination radius. In order to implement this recombination radius in Marlowe, we used the comparison of MD and Marlowe calculation in a range of ion energies in single crystal silicon target. As a result, the calculations showed that a single recombination radius of ~7.4 Å in Marlowe for a range of ion energies gives an excellent agreement with MD.

  8. The importance of GR for the radius of massive white dwarfs

    SciTech Connect

    Carvalho, Geanderson; Marinho, Rubens; Malheiro, Manuel

    2015-12-17

    In this work we investigate the structure of WD stars using the Tolman-Oppenheimer-Volkoff equations and compare with the Newtonian equations of gravitation in order to put in evidence the importance of the General Relativity in the study of these stars. Instead of using politropic equations of state we have solved the equations using the exact relativistic energy equation for the model of completely degenerate electron gas. We find a good fit of the TOV solution with the general EoS for the WD mass-radius diagram. We propose that our fit has to be used as relation between mass and radius for general relativistic WD instead of that Newtonian M ∼ 1/R{sup 3}, this fit is given by M = R/(a + bR + cR{sup 2} + dR{sup 3} + kR{sup 4}), where a, b, c and d are parameters and 1/k is the constant of the Newtonian mass-radius relation and it can be used in simulation study of binary systems that occurs accretion.

  9. Treatment of Distal Radius Fracture Nonunion With Posterior Interosseous Bone Flap

    PubMed Central

    Saremi, Hossein; Shahryar-Kamrani, Reza; Ghane, Bahareh; Yavarikia, Alireza

    2016-01-01

    Background Nonunion of distal radius fractures is disabling. Treatment is difficult and the results are not predictable. However, posterior interosseous bone flap (PIBF) has been successful in treating forearm nonunion. Objectives To treat distal radius fracture nonunion with PIBF as a new procedure. Patients and Methods This prospective non-randomized cohort study was performed at two hospitals in Tehran between January 2011 and September 2015. PIBFs were applied in nine patients (10 nonunions) with a mean age of 55 years. Union success rate, grip strength, wrist range of motion, and forearm rotation were then evaluated. Results Although four of the patients had a history of infection, all participants achieved fracture union at a mean time of 3.8 months. Grip strength improved by 12.4 kg. There was also 36° improvement in wrist flexion, 20° improvement in wrist extension, 60° improvement in forearm supination, and 46° improvement in forearm pronation. The range of motion and grip strength improvements were significant. Conclusions Pedicled PIBF is a new option for treating distal radius fracture nonunion. The results are predictable in achieving union and good function, and this technique can be successfully used in cases with extensive soft-tissue damage or infection.

  10. Determination of recombination radius in Si for binary collision approximation codes

    NASA Astrophysics Data System (ADS)

    Vizkelethy, Gyorgy; Foiles, Stephen M.

    2016-03-01

    Displacement damage caused by ions or neutrons in microelectronic devices can have significant effect on the performance of these devices. Therefore, it is important to predict not only the displacement damage profile, but also its magnitude precisely. Analytical methods and binary collision approximation codes working with amorphous targets use the concept of displacement energy, the energy that a lattice atom has to receive to create a permanent replacement. It was found that this "displacement energy" is direction dependent; it can range from 12 to 32 eV in silicon. Obviously, this model fails in BCA codes that work with crystalline targets, such as Marlowe. Marlowe does not use displacement energy; instead, it uses lattice binding energy only and then pairs the interstitial atoms with vacancies. Then based on the configuration of the Frenkel pairs it classifies them as close, near, or distant pairs, and considers the distant pairs the permanent replacements. Unfortunately, this separation is an ad hoc assumption, and the results do not agree with molecular dynamics calculations. After irradiation, there is a prompt recombination of interstitials and vacancies if they are nearby, within a recombination radius. In order to implement this recombination radius in Marlowe, we used the comparison of MD and Marlowe calculation in a range of ion energies in single crystal silicon target. The calculations showed that a single recombination radius of ∼7.4 Å in Marlowe for a range of ion energies gives an excellent agreement with MD.

  11. Monitoring the Solar Radius from the Royal Observatory of the Spanish Navy since 1773

    NASA Astrophysics Data System (ADS)

    Vaquero, J. M.; Gallego, M. C.; Ruiz-Lorenzo, J. J.; López-Moratalla, T.; Carrasco, V. M. S.; Aparicio, A. J. P.; González-González, F. J.; Hernández-García, E.

    2016-08-01

    The solar diameter has been monitored at the Royal Observatory of the Spanish Navy (today the Real Instituto y Observatorio de la Armada: ROA) almost continuously since its creation in 1753 ( i.e. during the past 250 years). After a painstaking effort to collect data in the historical archive of this institution, we present here the data of the solar semidiameter from 1773 to 2006, making up an extensive new database for solar-radius measurements, which can be considered. We have calculated the solar semidiameter from the transit times registered by the observers (except for values of the solar radius from the modern Danjon astrolabe, which were published by ROA). These data were analysed to reveal any significant long-term trends, but no such trends were found. Therefore, the data sample confirms the constancy of the solar diameter during the past 250 years (approximately) within instrumental and methodological limits. Moreover, no relationship between solar radius and the new sunspot-number index has been found from measurements of the ROA. Finally, the mean value for the solar semidiameter (with one standard deviation) calculated from the observations made in the ROA (1773 - 2006), after applying corrections for refraction and diffraction, is equal to 958.87^''±1.77^''.

  12. Tool holder for preparation and inspection of a radiused edge cutting tool

    DOEpatents

    Asmanes, Charles

    1979-01-01

    A tool holding fixture is provided for removably holding a radiused edge cutting tool in a tool edge lapping apparatus. The fixture allows the operator to preset the lapping radius and angle before the tool holder is placed in the fixture and the holder may be removed from the lapping apparatus to inspect the tool and simply replaced in the fixture to continue lapping in accordance with a precise alignment without realignment of the tool relative to the lap. The tool holder includes a pair of self aligning bearings in the form of precision formed steel balls connected together by a rigid shaft. The tool is held by an arm extending from the shaft and the balls set in fixed position bearing cups and the holder is oscillated back and forth about a fixed axis of rotation to lap the tool radius by means of a reversibly driven belt-pulley arrangement coupled to the shaft between the bearings. To temporarily remove the holder, the drive belt is slipped over the rearward end of the holder and the holder is lifted out of the bearing cups.

  13. Radius vertical graded nanoscale interlaced-coupled photonic crystal sensors array

    NASA Astrophysics Data System (ADS)

    Zhang, Pan; Tian, Huiping; Yang, Daquan; Liu, Qi; Zhou, Jian; Huang, Lijun; Ji, Yuefeng

    2015-11-01

    A radius vertical graded photonic crystal sensors array based on a monolithic substrate is proposed, which is potentially to be used as label-free detection in aqueous environments. The sensors array device consists of five resonant cavities including three H1 cavities and two L2 cavities which are interlaced-coupled to a radius vertical graded single photonic crystal line defect waveguide (W1). Each resonator has a different resonant wavelength dip which can shift independently with crosstalk lower than -13 dB in response to the refractive index change of air holes around every cavity. With three-dimensional finite-difference time-domain (3D-FDTD) method, simulation results demonstrate that the quality factors of microcavities are over 104. Besides, the refractive index sensitivity is 100 nm/RIU with the detection limit approximately of 5.63×10-4. Meanwhile, the radius vertical graded photonic crystal with more interlaced cavities is more suited to ultracompact optical monolithic integration.

  14. On the Radius Anomaly of Hot Jupiters: Reexamination of the Possibility and Impact of Layered Convection

    NASA Astrophysics Data System (ADS)

    Kurokawa, Hiroyuki; Inutsuka, Shu-ichiro

    2015-12-01

    Observations have revealed that a significant number of hot Jupiters have anomalously large radii. Layered convection induced by compositional inhomogeneity has been proposed to account for the radius anomaly of hot Jupiters. To reexamine the impact of the compositional inhomogeneity, we perform an evolutionary calculation by determining the convection regime at each evolutionary time step according to the criteria from linear analyses. It is shown that the impact is limited in the case of the monotonic gradient of heavy-element abundance. The layered convection is absent for the first 1 Gyr from the formation of hot Jupiters, and instead overturning convection develops. The superadiabaticity of the temperature gradient is limited by the neutrally stable state for the Ledoux stability criterion. The effect of the increased mass of heavy elements essentially compensates the effect of the delayed contraction on the planetary radius caused by compositional inhomogeneity. In addition, even in the case where the layered convection is artificially imposed, this mechanism requires extremely thin layers (˜101-103 cm) to account for the observed radius anomaly. The long-term stability of such thin layers remains to be studied. Therefore, if the criteria adopted in this paper are adequate, it might be difficult to explain the inflated radii of hot Jupiters by the monotonic gradient of heavy-element abundance alone.

  15. Solar spectral irradiance model validation using Solar Spectral Irradiance and Solar Radius measurements

    NASA Astrophysics Data System (ADS)

    Thuillier, Gérard; Zhu, Ping; Shapiro, Alexander; Sofia, Sabatino; Tagirov, Rinat; Van Ruymbeke, Michel; Schmutz, Werner

    2016-04-01

    The importance of the reliable solar spectral irradiance (SSI) data for solar and climate physics is now well acknowledged. In particular, the irradiance time series are necessary for most of the current studies concerning climate evolution. However, space instruments are vulnerable to the degradation due to the environment while ground based measurements are limited in wavelength range and need atmospheric effects corrections. This is why SSI modeling is necessary to understand the mechanism of the solar irradiance variability and to provide long and uninterrupted irradiance records to climate and Earth atmosphere scientists. Here we present COSI (COde for Solar Irradiance) model of the SSI variability. The COSI model is based on the Non local thermodynamic Equilibrium Spectral SYnthesis Code (NESSY). We validate NESSY by two independent datasets: - The SSI at solar minimum occurring in 2008, - The radius variation with wavelength and absolute values determined from PREMOS and BOS instruments onboard the PICARD spacecraft. Comparisons between modeling and measured SSI will be shown. However, since SSI measurements have an accuracy estimated between 2 to 3%, the comparison with the solar radius data provides a very important additional constrains on model. For that, 17 partial solar occultations by the Moon are used providing solar radii clearly showing the dependence of the solar radius with wavelength. These results are compared with the NESSY predictions. The agreement between NESSY and observations is within the model and measurements accuracy.

  16. Finite ion Larmor radius effects and wall effects on m = 1 instabilities

    SciTech Connect

    Cayton, T.E.

    1980-12-01

    A set of fluid-like equations that simultaneously includes effects due to geometry and finite ion gyroradii is used to examine the stability of a straight, radially diffuse screw pinch in the regime where the poloidal magnetic field is very small compared with the axial magnetic field. It is shown that this pinch may be rendered completely stable through a combination of finite Larmor radius effects and wall effects. Many of the m = 1 modes of the diffuse pinch can be stabilized by finite ion Larmor radius effects, just as all flute modes can be stabilized. Because of the special nature of the m = 1 eigenfunctions, finite ion gyroradius effects are negligible for the kink modes of very large wavelength. This special nature of the eigenfunctions, however, makes these modes good candidates for wall stabilization. The finite Larmor radius stabilization of m = 1 modes of a diffuse pinch is contrary to the conventional wisdom that has evolved from studies of sharp-boundary, skin-current models of the pinch.

  17. THE LICK AGN MONITORING PROJECT: ALTERNATE ROUTES TO A BROAD-LINE REGION RADIUS

    SciTech Connect

    Greene, Jenny E.; Hood, Carol E.; Barth, Aaron J.; Bentz, Misty C.; Walsh, Jonelle L.; Bennert, Vardha N.; Treu, Tommaso; Filippenko, Alexei V.; Gates, Elinor; Malkan, Matthew A.; Woo, Jong-Hak

    2010-11-01

    It is now possible to estimate black hole (BH) masses across cosmic time, using broad emission lines in active galaxies. This technique informs our views of how galaxies and their central BHs coevolve. Unfortunately, there are many outstanding uncertainties associated with these 'virial' mass estimates. One of these comes from using the accretion luminosity to infer a size for the broad-line region (BLR). Incorporating the new sample of low-luminosity active galaxies from our recent monitoring campaign at Lick Observatory, we recalibrate the radius-luminosity relation with tracers of the accretion luminosity other than the optical continuum. We find that the radius of the BLR scales as the square root of the X-ray and H{beta} luminosities, in agreement with recent optical studies. On the other hand, the scaling appears to be marginally steeper with narrow-line luminosities. This is consistent with a previously observed decrease in the ratio of narrow-line to X-ray luminosity with increasing total luminosity. The radius of the BLR correlates most tightly with H{beta} luminosity, while the X-ray and narrow-line relations both have comparable scatter of a factor of 2. These correlations provide useful alternative virial BH masses in objects with no detectable optical/UV continuum emission, such as high-redshift galaxies with broad emission lines, radio-loud objects, or local active galaxies with galaxy-dominated continua.

  18. The neutron star radius and the dense-matter equation of state

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

    A physical understanding of the behaviour of cold ultra-dense matter - at and above nuclear density - can only be achieved by the study of neutron stars, and the thermal emission from quiescent low-mass X-ray binaries inside globular clusters have proven very useful for that purpose. The recent 1.97±0.04 Msun measurement for the radio pulsar PSR 1614-2230 suggests that strange quark matter and hyperons/kaons condensate equations of states (EoS) are disfavoured, in favour of hadronic "normal matter" EoSs. Over much of the neutron star mass-radius parameter space, "normal matter" EoSs produce lines of quasi-constant radii (within the measurement uncertainties, of 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. 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 un-modelled spectrally hard components. Our results suggest a neutron star radius much smaller than previously reported, with a value Rns = 9.1±1.4 km, at 90% confidence, using conservative assumptions, which suggests that neutron start matter is best described by the softest "normal matter" equations of state.

  19. Radius of curvature and asphericity of the anterior and posterior surface of human cadaver crystalline lenses.

    PubMed

    Manns, Fabrice; Fernandez, Viviana; Zipper, Stanley; Sandadi, Samith; Hamaoui, Marie; Ho, Arthur; Parel, Jean Marie

    2004-01-01

    The purpose of this study was to measure the shape of the anterior and posterior surface of human cadaver lenses in situ using a corneal topography system. Measurements were performed on 13 pairs of eyes using the PAR Corneal Topography System (PAR-CTS). The age of the donors ranged from 46 to 93 years, with an average age of 76.4 years. Anterior lens topography was measured after excision of the cornea and iris. Posterior lens topography was measured after sectioning the posterior segment and adherent vitreous. The PAR-CTS files providing raw surface height were exported for analysis. In each surface, 18 meridians separated by 10 degrees were fitted using conic sections to obtain values of the apical radius of curvature (R) and shape factor (p). The average apical radius of curvature and asphericity were R=10.15+/-1.39mm and p=4.27+/-1.39 for the anterior surface and R=-6.25+/-0.79mm and p=-0.64+/-1.85 for the posterior surface. A significant variation of the radius of curvature and shape factor as a function of the meridian angle (lens astigmatism) was found in some lenses. Contrary to previous findings, the anterior lens surface was found to steepen toward the periphery.

  20. Laser confocal measurement system for curvature radius of lenses based on grating ruler

    NASA Astrophysics Data System (ADS)

    Tian, Jiwei; Wang, Yun; Zhou, Nan; Zhao, Weirui; Zhao, Weiqian

    2015-02-01

    In the modern optical measurement field, the radius of curvature (ROC) is one of the fundamental parameters of optical lens. Its measurement accuracy directly affects the other optical parameters, such as focal length, aberration and so on, which significantly affect the overall performance of the optical system. To meet the demand of measurement instruments for radius of curvature (ROC) with high accuracy in the market, we develop a laser confocal radius measurement system with grating ruler. The system uses the peak point of the confocal intensity curve to precisely identify the cat-eye and confocal positions and then measure the distance between these two positions by using the grating ruler, thereby achieving the high-precision measurement for the ROC. The system has advantages of high focusing sensitivity and anti-environment disturbance ability. And the preliminary theoretical analysis and experiments show that the measuring repeatability can be up to 0.8 um, which can provide an effective way for the accurate measurement of ROC.

  1. Contact Modelling of Large Radius Air Bending with Geometrically Exact Contact Algorithm

    NASA Astrophysics Data System (ADS)

    Vorkov, V.; Konyukhov, A.; Vandepitte, D.; Duflou, J. R.

    2016-08-01

    Usage of high-strength steels in conventional air bending is restricted due to limited bendability of these metals. Large-radius punches provide a typical approach for decreasing deformations during the bending process. However, as deflection progresses the loading scheme changes gradually. Therefore, modelling of the contact interaction is essential for an accurate description of the loading scheme. In the current contribution, the authors implemented a plane frictional contact element based on the penalty method. The geometrically exact contact algorithm is used for the penetration determination. The implementation is done using the OOFEM - open source finite element solver. In order to verify the simulation results, experiments have been conducted on a bending press brake for 4 mm Weldox 1300 with a punch radius of 30 mm and a die opening of 80 mm. The maximum error for the springback calculation is 0.87° for the bending angle of 144°. The contact interaction is a crucial part of large radius bending simulation and the implementation leads to a reliable solution for the springback angle.

  2. Probabilistic Mass-Radius Relationship for Sub-Neptune-Sized Planets

    NASA Astrophysics Data System (ADS)

    Wolfgang, Angie; Rogers, Leslie Anne; Ford, Eric B.

    2015-08-01

    The Kepler Mission has discovered thousands of super-Earths, paving the way for the first statistical studies of the dynamics, formation, and evolution of these planets. Planetary masses are an important physical property that these studies consider, and yet the vast majority of Kepler planet candidates do not have theirs measured. A key concern for these studies is therefore how to map the measured radii to mass estimates, in this regime of planetary sizes where there are no Solar System analogs. Previous works have derived deterministic, one-to-one relationships between radius and mass. However, if these planets span a range of compositions as expected, then an intrinsic scatter about this relationship must exist in the population. Here we present the first probabilistic mass-radius relationship (M-R relation) evaluated within a Bayesian framework, which both quantifies this intrinsic dispersion and the uncertainties on the M-R relation parameters given the data. We analyze how the details depend on the radius range of the sample, and on the method used to provide the mass measurements. Assuming that the M-R relation can be described as a power law with a dispersion that is constant and normally distributed, we find that M/M_Earth = 2.7 (R/R_Earth)^1.2 and a scatter in mass of 1.7 M_Earth is the "best-fit" probabilistic M-R relation for the sample of RV-measured transiting sub-Neptunes.

  3. Estimation of the radius of a star based on its effective temperature and surface gravity

    NASA Astrophysics Data System (ADS)

    Sichevskij, S. G.

    2016-06-01

    Amethod for determining the radius of a star using its effective temperature and surface gravity is proposed. The method assumes that the relationship between the radius, effective temperature, and surface gravity can be approximated using models for the internal structure and evolution of the star. The method is illustrated using the Geneva-Toulouse evolutionary computations for two metal abundances—solar and one-tenth of solar. Analysis of the systematic errors shows that the accuracy of the method is better than 10% over most part of the Hertzsprung-Russell diagram, and is about 5% for main-sequence stars. The maximum relative systematic error due to the simplifications underlying the method is about 15%. A test using eclipsing binaries confirms the viability of the proposed method for estimating stellar radii. In the region of the main sequence, systematic deviations do not exceed 2%, and the relative standard deviation is ≤4.7%. It is expected that th maximum relative error over the rest of the Hertzsprung-Russell diagram will likewise be close to the systematic error, about 15-20%. The method is applied to estimate the radii of model stellar atmospheres. Such estimates can be used to synthesize the color index and luminosity of a star. The method can be used whenever accuracies of about 10% in the estimated stellar radius and luminosity are acceptable.

  4. Towards a measurement of the proton radius using the Lamb shift in hydrogen

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    The discrepancy between the charge radius of the proton, measured using muon-proton interactions versus electron-proton interactions, constitutes the proton radius puzzle [Pohl et al., Nature 466:213 (2010), arXiv:1301.0905 (2013), Science 339:417 (2013)]. To aid in a resolution of the proton radius puzzle, we are developing an experiment with a fast metastable hydrogen beam, to measure the n =2 Lamb shift using the microwave separated oscillatory fields (SOF) technique. To avoid systematic effects from the frequency-dependent response of our microwave system, the measurement will use an SOF technique [Klein et al., Phys. Rev. A 36, 3494 (1987)], in which the frequency is fixed and the relative phase is varied. We report on the current status of the experiment, including metastable hydrogen beam production by charge exchange of protons with a molecular hydrogen target, hyperfine-state preparation using microwaves, and Lyman-alpha photon detection using a large-solid-angle high-efficiency detector.

  5. Bone geometry, density, and strength indices of the distal radius reflect loading via childhood gymnastic activity.

    PubMed

    Dowthwaite, Jodi N; Flowers, Portia P E; Spadaro, Joseph A; Scerpella, Tamara A

    2007-01-01

    The distal radius bears unique forces during gymnastic activity. Its relatively simple anatomy, minimal soft tissue envelope, and varied composition make the distal radius ideal for evaluating the effects of loading on bone properties. For 56 premenarcheal gymnasts and nongymnasts, ultradistal and 1/3 distal radius DXA scans measured bone mineral content (BMC), areal bone mineral density, and projected area. Simplified geometric models were used to generate bone mineral apparent density (BMAD), geometric indices, strength indices, and fall strength ratios. Ratios of regional BMC vs total body fat-free mass (FFM) were calculated. Separate Tanner I and II analyses of covariance adjusted bone parameters for age and height. Ratios were compared using maturity-matched analyses of variance. At the 1/3 region, periosteal width, BMC, cortical cross-sectional area, and section modulus were greater in gymnasts than nongymnasts (p<0.05); 1/3 BMAD means were equivalent. Ultradistal BMAD, BMC, and index for structural strength in axial compression were higher in gymnasts than nongymnasts; ultradistal periosteal width was only larger in Tanner I gymnasts. Fall strength ratios and BMC/FFM ratios were greater in gymnasts (p<0.05). Geometric and volumetric responses to mechanical loading are site specific during late childhood and early adolescence.

  6. Interior phase transformations and mass-radius relationships of silicon-carbon planets

    SciTech Connect

    Wilson, Hugh F.; Militzer, Burkhard

    2014-09-20

    Planets such as 55 Cancri e orbiting stars with a high carbon-to-oxygen ratio may consist primarily of silicon and carbon, with successive layers of carbon, silicon carbide, and iron. The behavior of silicon-carbon materials at the extreme pressures prevalent in planetary interiors, however, has not yet been sufficiently understood. In this work, we use simulations based on density functional theory to determine high-pressure phase transitions in the silicon-carbon system, including the prediction of new stable compounds with Si{sub 2}C and SiC{sub 2} stoichiometry at high pressures. We compute equations of state for these silicon-carbon compounds as a function of pressure, and hence derive interior structural models and mass-radius relationships for planets composed of silicon and carbon. Notably, we predict a substantially smaller radius for SiC planets than in previous models, and find that mass radius relationships for SiC planets are indistinguishable from those of silicate planets. We also compute a new equation of state for iron. We rederive interior models for 55 Cancri e and are able to place more stringent restrictions on its composition.

  7. Limb-sparing surgery using tantalum metal endoprosthesis in a dog with osteosarcoma of the distal radius

    PubMed Central

    MacDonald, Tamara L.; Schiller, Teresa D.

    2010-01-01

    A 5-year-old, male neutered, mixed breed dog was presented for left forelimb lameness and swelling over the left distal radius. A primary bone tumor of the distal radius was diagnosed and limb-sparing surgery of the left forelimb was performed using a tantalum metal-DCP endoprosthesis. Post-operative histopathology confirmed osteosarcoma. PMID:20676291

  8. Measure the Earth's Radius and the Speed of Light with Simple and Inexpensive Computer-Based Experiments

    ERIC Educational Resources Information Center

    Martin, Michael J.

    2004-01-01

    With new and inexpensive computer-based methods, measuring the speed of light and the Earth's radius--historically difficult endeavors--can be simple enough to be tackled by high school and college students working in labs that have limited budgets. In this article, the author describes two methods of estimating the Earth's radius using two…

  9. Gravitational anisotropies of gyromagnetic ratios and tests of general relativity

    NASA Astrophysics Data System (ADS)

    Gallop, J. C.; Petley, B. W.

    1983-05-01

    Consideration is given to experiments which may have demonstrated frequency shifts in an NMR clock that display a gravitational redshift. The experiments have been performed to test the Einstein equivalence principle that two clocks at the same point in space-time will run at the same rate. Comparisons have been made between the ticks of a cesium clock and the NMR clock, which has a time signal originating from the free precession of a sample of polarized nuclear spins in a stable and uniform magnetic field. Nonzero measurements of gravity-affected precessions have thus far not been obtained, indicating an isotropy of space or the exactness of the local Lorentz invariance. The NMR clocks, placed in the earth's magnetic field, have a sensitivity of 10 to the -17th eV for energy shifts caused by the gravitational field. Studies of the isotropy of the gravitational interaction for spin 1/2 particles in the fields of the earth, sun, and galaxy are shown to have been made with instruments which are barely capable of detecting the variations in the precession frequencies, and instrumentation which would be capable of detecting the changes are indicated.

  10. Gyromagnetic factors in {sup 144-150}Nd

    SciTech Connect

    Giannatiempo, A.

    2011-09-15

    The U(5) to SU(3) evolution of the nuclear structure in the even {sup 144-156}Nd isotopes has been investigated in the framework of the interacting boson approximation (IBA-2) model, taking into account the effect of the partial Z=64 subshell closure on the structure of the states of a collective nature. The analysis, which led to a satisfactory description of excitation energy patterns, quadrupole moments, and decay properties of the states (even when important M1 components were present in the transitions), is extended to the available data on g factors, in {sup 144-150}Nd. Their values are reasonably reproduced by the calculations.

  11. Bone Geometry, Density and Strength Indices of the Distal Radius Reflect Loading via Childhood Gymnastic Activity

    PubMed Central

    Dowthwaite, Jodi N.; Flowers, Portia P.E.; Spadaro, Joseph A.; Scerpella, Tamara A.

    2007-01-01

    The distal radius bears unique forces during gymnastic activity. Its relatively simple anatomy, minimal soft tissue envelope and varied composition make the distal radius ideal for evaluating the effects of loading on bone properties. For 56 premenarcheal gymnasts and non-gymnasts, ultradistal and 1/3 distal radius DXA scans measured bone mineral content (BMC), areal bone mineral density and projected area. Simplified geometric models were used to generate bone mineral apparent density (BMAD), geometric indices, strength indices and fall strength ratios. Ratios of regional BMC vs. total body fat free mass (FFM) were calculated. Separate Tanner I and II analyses of covariance adjusted bone parameters for age and height. Ratios were compared using maturity-matched analyses of variance. At the 1/3 region, periosteal width, BMC, cortical cross-sectional area, and section modulus were greater in gymnasts than non-gymnasts (p<0.05); 1/3 BMAD means were equivalent. Ultradistal BMAD, BMC and index for structural strength in axial compression were higher in gymnasts than non-gymnasts; ultradistal periosteal width was only larger in Tanner I gymnasts. Fall strength ratios and BMC/FFM ratios were greater in gymnasts (p<0.05). Geometric and volumetric responses to mechanical loading are site-specific during late childhood and early adolescence. The distal radius bears unique forces during gymnastic activity, and fan beam magnification error is negligible at this site, making it ideal for DXA evaluation of associated bone properties. For 56 premenarcheal gymnasts and non-gymnasts, ultradistal and 1/3 distal radius DXA scans measured bone mineral content, areal bone mineral density and projected area. Simplified geometric models were used to generate bone mineral apparent density, geometric indices, strength indices and fall strength ratios. Ratios of regional bone mineral content vs. total body fat free mass were calculated. Separate Tanner I and II analyses of covariance

  12. Saharan dust coarse mode effective radius retrieved from IASI over the Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Peyridieu, S.; Capelle, V.; Tsamalis, C.; Pierangelo, C.; Chédin, A.

    2012-04-01

    Infrared Atmospheric Sounder Interferometer (IASI) observations have been interpreted in terms of monthly mean, 1°x1°, 10 μm dust layer aerosol optical depth (DOD), mean altitude and coarse mode effective radius. The geographical area of the present study concerns the northern tropical Atlantic, a region regularly affected by strong dust events. The method developed relies on the construction of Look-Up-Tables computed for a large selection of atmospheric situations and observing conditions and follows three main steps: determination of the observed atmospheric thermodynamic situation, determination of the dust layer mean optical depth and altitude, and determination of the mean coarse mode effective radius, Reff. This presentation focuses on the latter variable. The main advantage of using infrared radiances is the fact that infrared radiation is mainly sensitive to coarse mode particles, the effect of the accumulation mode and of the width of the distribution being negligible, once the DOD is given. Therefore, the only remaining parameter to be retrieved is Reff. "Radius-Look-Up Tables", sampling different values of the dust infrared optical depth, mean altitude and Reff, using a monomodal lognormal size distribution, are built for four IASI channels close to 9.32 µm. They are selected for their high sensitivity to dust size and insensitivity to other atmospheric components or to dust asphericity. From an analysis of the performances of this algorithm made by Pierangelo et al. (2005) it results that the coarse mode effective radius is retrieved with an accuracy varying from 0.5 µm for smaller radii to 1 µm for larger radii. The monthly mean, 1°x1°, dust coarse mode effective radius is retrieved from IASI over the Atlantic Ocean for the period July 2007 to December 2011. Results compare well with measurements from aircraft and ground based campaigns, or sun-photometer observations (AERONET). During the dust season (summer), we find that Reff remains almost

  13. MASS/RADIUS CONSTRAINTS ON THE QUIESCENT NEUTRON STAR IN M13 USING HYDROGEN AND HELIUM ATMOSPHERES

    SciTech Connect

    Catuneanu, A.; Heinke, C. O.; Sivakoff, G. R.; Ho, W. C. G.; Servillat, M.

    2013-02-20

    The mass and radius of the neutron star (NS) in low-mass X-ray binaries can be obtained by fitting the X-ray spectrum of the NS in quiescence, and the mass and radius constrains the properties of dense matter in NS cores. A critical ingredient for spectral fits is the composition of the NS atmosphere: hydrogen atmospheres are assumed in most prior work, but helium atmospheres are possible if the donor star is a helium white dwarf. Here we perform spectral fits to XMM-Newton, Chandra, and ROSAT data of a quiescent NS in the globular cluster M13. This NS has the smallest inferred radius from previous spectral fitting. Assuming an atmosphere composed of hydrogen, we find a significantly larger radius, more consistent with those from other quiescent NSs. With a helium atmosphere (an equally acceptable fit), we find even larger values for the radius.

  14. Charge-radius change and nuclear moments in the heavy tin isotopes from laser spectroscopy: Charge radius of {sup 132}Sn

    SciTech Connect

    Le Blanc, F.; Cottereau, E.; Essabaa, S.; Obert, J.; Oms, J.; Ouchrif, A.; Roussiere, B.; Sauvage, J.; Verney, D.; Cabaret, L.; Pinard, J.; Crawford, J.E.; Lee, J.K.P.; Genevey, J.; Le Scornet, G.; Lettry, J.; Ravn, H.

    2005-09-01

    Laser spectroscopy measurements have been carried out on the neutron-rich tin isotopes with the COMPLIS experimental setup. Using the 5s{sup 2}5p{sup 23}P{sub 0}{yields}5s{sup 2}5p6s {sup 3}P{sub 1} optical transition, hyperfine spectra of {sup 126-132}Sn and {sup 125,127,129-131}Sn{sup m} were recorded for the first time. The nuclear moments and the mean square charge radius variation ({delta}) were extracted. From the quadrupole moment values, these nuclei appear to be spherical. The magnetic moments measured are thus compared with those predicted by spherical basis approaches. From the measured {delta}, the absolute charge radii of these isotopes were deduced in particular that of the doubly magic {sup 132}Sn nucleus. The comparison of the results with several mean-field-type calculations have shown that dynamical effects play an important role in the tin isotopes.

  15. Characterization of exoplanets from their formation. II. The planetary mass-radius relationship

    NASA Astrophysics Data System (ADS)

    Mordasini, C.; Alibert, Y.; Georgy, C.; Dittkrist, K.-M.; Klahr, H.; Henning, T.

    2012-11-01

    Context. The research of extrasolar planets has entered an era in which we characterize extrasolar planets. This has become possible with measurements of the radii of transiting planets and of the luminosity of planets observed by direct imaging. Meanwhile, the precision of radial velocity surveys makes it possible to discover not only giant planets but also very low-mass ones. Aims: Uniting all these different observational constraints into one coherent picture to better understand planet formation is an important and simultaneously difficult undertaking. One approach is to develop a theoretical model that can make testable predictions for all these observational techniques. Our goal is to have such a model and use it in population synthesis calculations. Methods: In a companion paper, we described how we have extended our formation model into a self-consistently coupled formation and evolution model. In this second paper, we first continue with the model description. We describe how we calculate the internal structure of the solid core of the planet and include radiogenic heating. We also introduce an upgrade of the protoplanetary disk model. Finally, we use the upgraded model in population synthesis calculations. Results: We present how the planetary mass-radius relationship of planets with primordial H2/He envelopes forms and evolves in time. The basic shape of the mass-radius relationship can be understood from the core accretion model. Low-mass planets cannot bind massive envelopes, while super-critical cores necessarily trigger runway gas accretion, leading to "forbidden" zones in the M - R plane. For a given mass, there is a considerable diversity of radii, mainly due to different bulk compositions, reflecting different formation histories. We compare the synthetic M - R plane with the observed one, finding good agreement for a > 0.1 AU. The synthetic planetary radius distribution is characterized by a strong increase towards small R and a second, lower

  16. Is the proton radius a player in the redefinition of the International System of Units?

    PubMed

    Nez, F; Antognini, A; Amaro, F D; Biraben, F; Cardoso, J M R; Covita, D; Dax, A; Dhawan, S; Fernandes, L; Giesen, A; Graf, T; Hänsch, T W; Indelicato, P; Julien, L; Kao, C-Y; Knowles, P E; Le Bigot, E; Liu, Y-W; Lopes, J A M; Ludhova, L; Monteiro, C M B; Mulhauser, F; Nebel, T; Rabinowitz, P; dos Santos, J M F; Schaller, L; Schuhmann, K; Schwob, C; Taqqu, D; Veloso, J F C A; Kottmann, F; Pohl, R

    2011-10-28

    It is now recognized that the International System of Units (SI units) will be redefined in terms of fundamental constants, even if the date when this will occur is still under debate. Actually, the best estimate of fundamental constant values is given by a least-squares adjustment, carried out under the auspices of the Committee on Data for Science and Technology (CODATA) Task Group on Fundamental Constants. This adjustment provides a significant measure of the correctness and overall consistency of the basic theories and experimental methods of physics using the values of the constants obtained from widely differing experiments. The physical theories that underlie this adjustment are assumed to be valid, such as quantum electrodynamics (QED). Testing QED, one of the most precise theories is the aim of many accurate experiments. The calculations and the corresponding experiments can be carried out either on a boundless system, such as the electron magnetic moment anomaly, or on a bound system, such as atomic hydrogen. The value of fundamental constants can be deduced from the comparison of theory and experiment. For example, using QED calculations, the value of the fine structure constant given by the CODATA is mainly inferred from the measurement of the electron magnetic moment anomaly carried out by Gabrielse's group. (Hanneke et al. 2008 Phys. Rev. Lett. 100, 120801) The value of the Rydberg constant is known from two-photon spectroscopy of hydrogen combined with accurate theoretical quantities. The Rydberg constant, determined by the comparison of theory and experiment using atomic hydrogen, is known with a relative uncertainty of 6.6×10(-12). It is one of the most accurate fundamental constants to date. A careful analysis shows that knowledge of the electrical size of the proton is nowadays a limitation in this comparison. The aim of muonic hydrogen spectroscopy was to obtain an accurate value of the proton charge radius. However, the value deduced from this

  17. Distal Radius Volar Rim Fracture Fixation Using DePuy-Synthes Volar Rim Plate.

    PubMed

    Kachooei, Amir Reza; Tarabochia, Matthew; Jupiter, Jesse B

    2016-03-01

    Background To assess the results of distal radius fractures with the involvement of the volar rim fixed with the DePuy-Synthes Volar Rim Plate. Case Description We searched for the patients with volar rim fracture and/or volar rim fractures as part of a complex fracture fixed with a volar rim plate. Ten patients met the inclusion criteria: three patients with type 23B3, six patients with type 23C, and one patient with very distal type 23A. The mean follow-up was 14 months (range: 2-26). Fractures healed in all patients. Of the three patients with isolated volar rim fractures (type 23B3), two patients had no detectable deficits in motion. These patients had an average Gartland and Werley score of 9 (range: 2-14). Of the other seven patients (six with type 23C and one with type 23A fracture), three patients healed with full range of motion and four had some deficits in range of motion. Two patients had excellent results, three had good results, and two had fair results using the Gartland and Werley categorical rating. One patient healed with a shortened radius and ulnar impingement requiring a second surgery for ulnar head resection arthroplasty. Literature Review Results after nonoperative treatment of volar rim fractures are not satisfactory and often require subsequent corrective osteotomy. Satisfactory outcomes are achieved when the fragments are well reduced and secured regardless of the device type. Clinical Relevance Volar rim plates give an adequate buttress of the volar radius distal to volar projection of the lunate facet and do not interfere with wrist mobility. Furthermore, the dorsal fragments can be fixed securely through the volar approach eliminating the need for a secondary posterior incision. However, patients should be informed of the potential problems and the need to remove the plate if symptoms develop.

  18. Distal radius geometry and skeletal strength indices after peripubertal artistic gymnastics

    PubMed Central

    Scerpella, T. A.

    2011-01-01

    Summary Development of optimal skeletal strength should decrease adult bone fragility. Nongymnasts (NON) were compared with girls exposed to gymnastics during growth (EX/GYM), using peripheral quantitative computed tomography (pQCT) to evaluate postmenarcheal bone geometry, density, and strength. Pre- and perimenarcheal gymnastic loading yields advantages in indices of postmenarcheal bone geometry and skeletal strength. Introduction Two prior studies using pQCT have reported bone density and size advantages in Tanner I/II gymnasts, but none describe gymnasts’ bone properties later in adolescence. The current study used pQCT to evaluate whether girls exposed to gymnastics during late childhood growth and perimenarcheal growth exhibited greater indices of distal radius geometry, density, and skeletal strength. Methods Postmenarcheal subjects underwent 4% and 33% distal radius pQCT scans, yielding: 1) vBMD and cross-sectional areas (CSA) (total bone, compartments); 2) polar strength-strain index; 3) index of structural strength in axial compression. Output was compared for EX/GYM vs. NON, adjusting for gynecological age and stature (maturity and body size), reporting means, standard errors, and significance. Results Sixteen postmenarcheal EX/GYM (age 16.7 years; gynecological age 3.4 years) and 13 NON (age 16.2 years; gynecological age 3.6 years) were evaluated. At both diaphysis and metaphysis, EX/GYM exhibited greater CSA and bone strength indices than NON; EX/GYM exhibited 79% larger intramedullary CSA than NON (p<0.05). EX/GYM had significantly higher 4% trabecular vBMD; differences were not detected for 4% total vBMD and 33% cortical vBMD. Conclusions Following pre-/perimenarcheal gymnastic exposure, relative to nongymnasts, postmenarcheal EX/GYM demonstrated greater indices of distal radius geometry and skeletal strength (metaphysis and diaphysis) with greater metaphyseal trabecular vBMD; larger intramedullary cavity size was particularly striking. PMID

  19. How to Constrain Your M Dwarf: Measuring Effective Temperature, Bolometric Luminosity, Mass, and Radius

    NASA Astrophysics Data System (ADS)

    Mann, Andrew W.; Feiden, Gregory A.; Gaidos, Eric; Boyajian, Tabetha; von Braun, Kaspar

    2015-05-01

    Precise and accurate parameters for late-type (late K and M) dwarf stars are important for characterization of any orbiting planets, but such determinations have been hampered by these stars’ complex spectra and dissimilarity to the Sun. We exploit an empirically calibrated method to estimate spectroscopic effective temperature (Teff) and the Stefan-Boltzmann law to determine radii of 183 nearby K7-M7 single stars with a precision of 2%-5%. Our improved stellar parameters enable us to develop model-independent relations between Teff or absolute magnitude and radius, as well as between color and Teff. The derived Teff-radius relation depends strongly on [Fe/H], as predicted by theory. The relation between absolute KS magnitude and radius can predict radii accurate to ≃ 3%. We derive bolometric corrections to the V{{R}C}{{I}C}grizJH{{K}S} and Gaia passbands as a function of color, accurate to 1%-3%. We confront the reliability of predictions from Dartmouth stellar evolution models using a Markov chain Monte Carlo to find the values of unobservable model parameters (mass, age) that best reproduce the observed effective temperature and bolometric flux while satisfying constraints on distance and metallicity as Bayesian priors. With the inferred masses we derive a semi-empirical mass-absolute magnitude relation with a scatter of 2% in mass. The best-agreement models overpredict stellar Teff values by an average of 2.2% and underpredict stellar radii by 4.6%, similar to differences with values from low-mass eclipsing binaries. These differences are not correlated with metallicity, mass, or indicators of activity, suggesting issues with the underlying model assumptions, e.g., opacities or convective mixing length.

  20. The Impact of Subsampling on MODIS Level-3 Statistics of Cloud Optical Thickness and Effective Radius

    NASA Technical Reports Server (NTRS)

    Oreopoulos, Lazaros

    2004-01-01

    The MODIS Level-3 optical thickness and effective radius cloud product is a gridded l deg. x 1 deg. dataset that is derived from aggregation and subsampling at 5 km of 1 km, resolution Level-2 orbital swath data (Level-2 granules). This study examines the impact of the 5 km subsampling on the mean, standard deviation and inhomogeneity parameter statistics of optical thickness and effective radius. The methodology is simple and consists of estimating mean errors for a large collection of Terra and Aqua Level-2 granules by taking the difference of the statistics at the original and subsampled resolutions. It is shown that the Level-3 sampling does not affect the various quantities investigated to the same degree, with second order moments suffering greater subsampling errors, as expected. Mean errors drop dramatically when averages over a sufficient number of regions (e.g., monthly and/or latitudinal averages) are taken, pointing to a dominance of errors that are of random nature. When histograms built from subsampled data with the same binning rules as in the Level-3 dataset are used to reconstruct the quantities of interest, the mean errors do not deteriorate significantly. The results in this paper provide guidance to users of MODIS Level-3 optical thickness and effective radius cloud products on the range of errors due to subsampling they should expect and perhaps account for, in scientific work with this dataset. In general, subsampling errors should not be a serious concern when moderate temporal and/or spatial averaging is performed.

  1. [Efficacy of compound Xiatianwu tablets in elderly patients with osteoporotic distal radius fractures].

    PubMed

    Zhang, Bin; Chen, Gang; Li, Hai-long; Ren, Hai-peng; Yang, Tao; Chen, Min; Guo, Li-gang

    2015-06-01

    Xiatianwu tablet is based on the theory of traditional Chinese medicine (TCM), combined with modern TCM pharmacology and selected 33 famous traditional Chinese crude drugs to compose. Its recipe helps cure rheumatism, relax tendons, promote blood circulation to relieve pain, et al. Although Xiatianwu tablets are widely applied to clinical remedy such as rheumatic arthritis, lumbar disc hernia, osteoarthritis and so on, there is no report about its application in fracture. This article is to observe the efficacy of compound Xiatianwu tablets in elderly patients with osteoporotic distal radius fractures and its impact on the wrist function and complications. 180 elderly patients with osteoporotic distal radius fractures, from January 2011 to June 2014, were divided into observation group and control group by the method of random number table, each group had 90 cases. The control group were gave Caltrate D after manipulative reduction and plaster immobilization, observation group were treated with compound Xiatianwu tablets in the basis of the control group. Efficacy, wrist function and complication rates were observed in two groups after treatment. The excellent and good rate was 95.56% in observation group better than 77.78% in control group, the difference was statistically significant (χ2 = 4.712, P < 0.05). The complication rate in observation group was significantly lower compared with the control group (P < 0.05). This study shows that compound Xiatianwu tablets can improve the efficacy in elderly patients with osteoporotic distal radius fractures, reduce the incidence of complications and relieve the pain of patients which plays a significant role in improving the quality of life. PMID:26591540

  2. MRI of bone marrow in the distal radius: in vivo precision of effective transverse relaxation times

    NASA Technical Reports Server (NTRS)

    Grampp, S.; Majumdar, S.; Jergas, M.; Lang, P.; Gies, A.; Genant, H. K.

    1995-01-01

    The effective transverse relaxation time T2* is influenced by the presence of trabecular bone, and can potentially provide a measure of bone density as well as bone structure. We determined the in vivo precision of T2* in repeated bone marrow measurements. The T2* measurements of the bone marrow of the distal radius were performed twice within 2 weeks in six healthy young volunteers using a modified water-presaturated 3D Gradient-Recalled Acquisition at Steady State (GRASS) sequence with TE 7, 10, 12, 20, and 30; TR 67; flip angle (FA) 90 degrees. An axial volume covering a length of 5.6 cm in the distal radius was measured. Regions of interest (ROIs) were determined manually and consisted of the entire trabecular bone cross-section extending proximally from the radial subchondral endplate. Reproducibility of T2* and area measurements was expressed as the absolute precision error (standard deviation [SD] in ms or mm2) or as the relative precision error (SD/mean x 100, or coefficient of variation [CV] in %) between the two-point measurements. Short-term precision of T2* and area measurements varied depending on section thickness and location of the ROI in the distal radius. Absolute precision errors for T2* times were between 1.3 and 2.9 ms (relative precision errors 3.8-9.5 %) and for area measurements between 20 and 55 mm2 (relative precision errors 5.1-16.4%). This MR technique for quantitative assessment of trabecular bone density showed reasonable reproducibility in vivo and is a promising future tool for the assessment of osteoporosis.

  3. THE RADIUS DISCREPANCY IN LOW-MASS STARS: SINGLE VERSUS BINARIES

    SciTech Connect

    Spada, F.; Demarque, P.; Kim, Y.-C.; Sills, A.

    2013-10-20

    A long-standing issue in the theory of low-mass stars is the discrepancy between predicted and observed radii and effective temperatures. In spite of the increasing availability of very precise radius determinations from eclipsing binaries and interferometric measurements of radii of single stars, there is no unanimous consensus on the extent (or even the existence) of the discrepancy and on its connection with other stellar properties (e.g., metallicity, magnetic activity). We investigate the radius discrepancy phenomenon using the best data currently available (accuracy ∼< 5%). We have constructed a grid of stellar models covering the entire range of low-mass stars (0.1-1.25 M{sub ☉}) and various choices of the metallicity and mixing length parameter, α. We used an improved version of the Yale Rotational stellar Evolution Code, implementing surface boundary conditions based on the most up-to-date PHOENIX atmosphere models. Our models are in good agreement with others in the literature and improve and extend the low mass end of the Yale-Yonsei isochrones. Our calculations include rotation-related quantities, such as moments of inertia and convective turnover timescales, useful in studies of magnetic activity and rotational evolution of solar-like stars. Consistent with previous works, we find that both binaries and single stars have radii inflated by about 3% with respect to the theoretical models; among binaries, the components of short orbital period systems are found to be the most deviant. We conclude that both binaries and single stars are comparably affected by the radius discrepancy phenomenon.

  4. Determination of recombination radius in Si for binary collision approximation codes

    DOE PAGES

    Vizkelethy, Gyorgy; Foiles, Stephen M.

    2015-09-11

    Displacement damage caused by ions or neutrons in microelectronic devices can have significant effect on the performance of these devices. Therefore, it is important to predict not only the displacement damage profile, but also its magnitude precisely. Analytical methods and binary collision approximation codes working with amorphous targets use the concept of displacement energy, the energy that a lattice atom has to receive to create a permanent replacement. It was found that this “displacement energy” is direction dependent; it can range from 12 to 32 eV in silicon. Obviously, this model fails in BCA codes that work with crystalline targets,more » such as Marlowe. Marlowe does not use displacement energy; instead, it uses lattice binding energy only and then pairs the interstitial atoms with vacancies. Then based on the configuration of the Frenkel pairs it classifies them as close, near, or distant pairs, and considers the distant pairs the permanent replacements. Unfortunately, this separation is an ad hoc assumption, and the results do not agree with molecular dynamics calculations. After irradiation, there is a prompt recombination of interstitials and vacancies if they are nearby, within a recombination radius. In order to implement this recombination radius in Marlowe, we used the comparison of MD and Marlowe calculation in a range of ion energies in single crystal silicon target. As a result, the calculations showed that a single recombination radius of ~7.4 Å in Marlowe for a range of ion energies gives an excellent agreement with MD.« less

  5. Measurement of Malrotation on Direct Radiography in Pediatric Distal Radius Fractures

    PubMed Central

    Duymus, Tahir Mutlu; Mutlu, Serhat; Komur, Baran; Mutlu, Harun; Yucel, Bulent; Parmaksizoglu, Atilla Sancar

    2016-01-01

    Abstract The aim of this prospective study was to test a mathematical method of measuring the malrotation of pediatric distal radius fractures (PDRFs) from direct radiographs. A total of 70 pediatric patients who presented at the Emergency Department with a distal radius fracture were evaluated. For 38 selected patients conservative treatment for PDRF was planned. Anteroposterior and lateral radiographs were taken of all of the patients for comparison before and after reduction. Radius bone diameters were measured in the coronal and sagittal planes on the healthy and fractured sides. Using the diameter values on the healthy side and the new diameter values on the fractured side in the rotation formula, the degree of malrotation between the fracture ends was calculated. The mean follow-up period was 13.5 months. Patients’ mean age was 10.00 ± 3.19 years (range, 4–12 years). The rotation degree in the sagittal plane significantly differed between the proximal (26.52°±2.84°) and distal fracture ends (20.96°±2.73°) (P = 0.001). The rotation degree in the coronal plane significantly differed between the proximal (26.70°±2.38°) and distal fracture ends (20.26°±2.86°) (P = 0.001). The net rotation deformity of the fracture line was determined to be 5.55°± 3.54° on lateral radiographs and 5.44°± 3.35° on anteroposterior radiographs, no significant difference was observed between measurements (P >0.05). The malrotation deformity in PDRF occurs with greater rotation in the proximal fragment than in the distal fragment. The net rotation deformity created between the fracture ends can be calculated on direct radiographs. Level of Evidence: Diagnostic, Level II PMID:27149480

  6. Combining ergometer exercise and artificial gravity in a compact-radius centrifuge

    NASA Astrophysics Data System (ADS)

    Diaz, Ana; Trigg, Chris; Young, Laurence R.

    2015-08-01

    Humans experience physiological deconditioning during space missions, primarily attributable to weightlessness. Some of these adverse consequences include bone loss, muscle atrophy, sensory-motor deconditioning, and cardiovascular alteration, which may lead to orthostatic intolerance when astronauts return to Earth. Artificial gravity could provide a comprehensive countermeasure capable of challenging all the physiological systems at once, particularly if combined with exercise, thereby maintaining overall health during extended exposure to weightlessness. A new Compact Radius Centrifuge (CRC) platform was designed and built on the existing Short Radius Centrifuge (SRC) at the Massachusetts Institute of Technology (MIT). The centrifuge has been constrained to a radius of 1.4 m, the upper radial limit for a centrifuge to fit within an International Space Station (ISS) module without extensive structural alterations. In addition, a cycle ergometer has been added for exercise during centrifugation. The CRC now includes sensors of foot forces, cardiovascular parameters, and leg muscle electromyography. An initial human experiment was conducted on 12 subjects to analyze the effects of different artificial gravity levels (0 g, 1 g, and 1.4 g, measured at the feet) and ergometer exercise intensities (25 W warm-up, 50 W moderate and 100 W vigorous) on the musculoskeletal function as well as motion sickness and comfort. Foot forces were measured during the centrifuge runs, and subjective comfort and motion sickness data were gathered after each session. Preliminary results indicate that ergometer exercise on a centrifuge may be effective in improving musculoskeletal function. The combination is well tolerated and motion sickness is minimal. The MIT CRC is a novel platform for future studies of exercise combined with artificial gravity. This combination may be effective as a countermeasure to space physiological deconditioning.

  7. Probabilistic Mass-Radius Relationship for Sub-Neptune-Sized Planets

    NASA Astrophysics Data System (ADS)

    Wolfgang, Angie; Rogers, Leslie A.; Ford, Eric B.

    2016-07-01

    The Kepler Mission has discovered thousands of planets with radii <4 {R}\\oplus , paving the way for the first statistical studies of the dynamics, formation, and evolution of these sub-Neptunes and super-Earths. Planetary masses are an important physical property for these studies, and yet the vast majority of Kepler planet candidates do not have theirs measured. A key concern is therefore how to map the measured radii to mass estimates in this Earth-to-Neptune size range where there are no Solar System analogs. Previous works have derived deterministic, one-to-one relationships between radius and mass. However, if these planets span a range of compositions as expected, then an intrinsic scatter about this relationship must exist in the population. Here we present the first probabilistic mass–radius relationship (M–R relation) evaluated within a Bayesian framework, which both quantifies this intrinsic dispersion and the uncertainties on the M–R relation parameters. We analyze how the results depend on the radius range of the sample, and on how the masses were measured. Assuming that the M–R relation can be described as a power law with a dispersion that is constant and normally distributed, we find that M/{M}\\oplus =2.7{(R/{R}\\oplus )}1.3, a scatter in mass of 1.9{M}\\oplus , and a mass constraint to physically plausible densities, is the “best-fit” probabilistic M–R relation for the sample of RV-measured transiting sub-Neptunes (R pl < 4 {R}\\oplus ). More broadly, this work provides a framework for further analyses of the M–R relation and its probable dependencies on period and stellar properties.

  8. Can we constrain the interior structure of rocky exoplanets from mass and radius measurements?

    NASA Astrophysics Data System (ADS)

    Dorn, Caroline; Khan, Amir; Heng, Kevin; Connolly, James A. D.; Alibert, Yann; Benz, Willy; Tackley, Paul

    2015-05-01

    Aims: We present an inversion method based on Bayesian analysis to constrain the interior structure of terrestrial exoplanets, in the form of chemical composition of the mantle and core size. Specifically, we identify what parts of the interior structure of terrestrial exoplanets can be determined from observations of mass, radius, and stellar elemental abundances. Methods: We perform a full probabilistic inverse analysis to formally account for observational and model uncertainties and obtain confidence regions of interior structure models. This enables us to characterize how model variability depends on data and associated uncertainties. Results: We test our method on terrestrial solar system planets and find that our model predictions are consistent with independent estimates. Furthermore, we apply our method to synthetic exoplanets up to 10 Earth masses and up to 1.7 Earth radii, and to exoplanet Kepler-36b. Importantly, the inversion strategy proposed here provides a framework for understanding the level of precision required to characterize the interior of exoplanets. Conclusions: Our main conclusions are (1) observations of mass and radius are sufficient to constrain core size; (2) stellar elemental abundances (Fe, Si, Mg) are principal constraints to reduce degeneracy in interior structure models and to constrain mantle composition; (3) the inherent degeneracy in determining interior structure from mass and radius observations does not only depend on measurement accuracies, but also on the actual size and density of the exoplanet. We argue that precise observations of stellar elemental abundances are central in order to place constraints on planetary bulk composition and to reduce model degeneracy. We provide a general methodology of analyzing interior structures of exoplanets that may help to understand how interior models are distributed among star systems. The methodology we propose is sufficiently general to allow its future extension to more complex

  9. Probabilistic Mass-Radius Relationship for Sub-Neptune-Sized Planets

    NASA Astrophysics Data System (ADS)

    Wolfgang, Angie; Rogers, Leslie A.; Ford, Eric B.

    2016-07-01

    The Kepler Mission has discovered thousands of planets with radii <4 {R}\\oplus , paving the way for the first statistical studies of the dynamics, formation, and evolution of these sub-Neptunes and super-Earths. Planetary masses are an important physical property for these studies, and yet the vast majority of Kepler planet candidates do not have theirs measured. A key concern is therefore how to map the measured radii to mass estimates in this Earth-to-Neptune size range where there are no Solar System analogs. Previous works have derived deterministic, one-to-one relationships between radius and mass. However, if these planets span a range of compositions as expected, then an intrinsic scatter about this relationship must exist in the population. Here we present the first probabilistic mass-radius relationship (M-R relation) evaluated within a Bayesian framework, which both quantifies this intrinsic dispersion and the uncertainties on the M-R relation parameters. We analyze how the results depend on the radius range of the sample, and on how the masses were measured. Assuming that the M-R relation can be described as a power law with a dispersion that is constant and normally distributed, we find that M/{M}\\oplus =2.7{(R/{R}\\oplus )}1.3, a scatter in mass of 1.9{M}\\oplus , and a mass constraint to physically plausible densities, is the “best-fit” probabilistic M-R relation for the sample of RV-measured transiting sub-Neptunes (R pl < 4 {R}\\oplus ). More broadly, this work provides a framework for further analyses of the M-R relation and its probable dependencies on period and stellar properties.

  10. THE MASS-RADIUS RELATION FOR 65 EXOPLANETS SMALLER THAN 4 EARTH RADII

    SciTech Connect

    Weiss, Lauren M.; Marcy, Geoffrey W.

    2014-03-01

    We study the masses and radii of 65 exoplanets smaller than 4 R {sub ⊕} with orbital periods shorter than 100 days. We calculate the weighted mean densities of planets in bins of 0.5 R {sub ⊕} and identify a density maximum of 7.6  g cm{sup –3} at 1.4 R {sub ⊕}. On average, planets with radii up to R {sub P} = 1.5 R {sub ⊕} increase in density with increasing radius. Above 1.5 R {sub ⊕}, the average planet density rapidly decreases with increasing radius, indicating that these planets have a large fraction of volatiles by volume overlying a rocky core. Including the solar system terrestrial planets with the exoplanets below 1.5 R {sub ⊕}, we find ρ{sub P} = 2.43 + 3.39(R {sub P}/R {sub ⊕}) g cm{sup –3} for R {sub P} < 1.5 R {sub ⊕}, which is consistent with rocky compositions. For 1.5 ≤ R {sub P}/R {sub ⊕} < 4, we find M {sub P}/M {sub ⊕} = 2.69(R {sub P}/R {sub ⊕}){sup 0.93}. The rms of planet masses to the fit between 1.5 and 4 R {sub ⊕} is 4.3 M {sub ⊕} with reduced χ{sup 2} = 6.2. The large scatter indicates a diversity in planet composition at a given radius. The compositional diversity can be due to planets of a given volume (as determined by their large H/He envelopes) containing rocky cores of different masses or compositions.

  11. Measurement of Gaussian laser beam radius using the knife-edge technique: improvement on data analysis

    SciTech Connect

    Araujo, Marcos A. de; Silva, Rubens; Lima, Emerson de; Pereira, Daniel P.; Oliveira, Paulo C. de

    2009-01-10

    We revisited the well known Khosrofian and Garetz inversion algorithm [Appl. Opt.22, 3406-3410 (1983)APOPAI0003-6935] that was developed to analyze data obtained by the application of the traveling knife-edge technique. We have analyzed the approximated fitting function that was used for adjusting their experimental data and have found that it is not optimized to work with a full range of the experimentally-measured data. We have numerically calculated a new set of coefficients, which makes the approximated function suitable for a full experimental range, considerably improving the accuracy of the measurement of a radius of a focused Gaussian laser beam.

  12. EXPLORATIONS INTO THE VIABILITY OF COUPLED RADIUS-ORBIT EVOLUTIONARY MODELS FOR INFLATED PLANETS

    SciTech Connect

    Ibgui, Laurent; Spiegel, David S.; Burrows, Adam E-mail: dsp@astro.princeton.edu

    2011-02-01

    The radii of some transiting extrasolar giant planets are larger than would be expected by the standard theory. We address this puzzle with the model of coupled radius-orbit tidal evolution developed by Ibgui and Burrows. The planetary radius is evolved self-consistently with orbital parameters, under the influence of tidal torques and tidal dissipation in the interior of the planet. A general feature of this model, which we have previously demonstrated in the generic case, is that a possible transient inflation of the planetary radius can temporarily interrupt its standard monotonic shrinking and can lead to the inflated radii that we observe. Importantly, we demonstrate that the use of a constant time lag model for the orbital evolution does not improve the accuracy of the evolutionary calculations. First, though formulated in a closed form by the equations of Hut, it is not valid at large eccentricities, as for the constant phase lag model truncated at the second order in eccentricity that we adopt; ambiguities in tidal theories are perhaps the most significant source of uncertainty in evolutionary calculations. Second, we find evolutionary tracks that fit within the 1{sigma} error bars, the radius, the eccentricity, and the semimajor axis of HD 209458b in its current estimated age range, using the constant time lag model, as we find fitting tracks with the constant phase lag model. Both models show that a bloated planet with a circular orbit may still be inflated, due to thermal inertia. We have modified our constant phase lag model to include an orbital period dependence of the tidal dissipation factor in the star, Q'{sub *} {proportional_to} P{sup {gamma}}, -1 {<=} {gamma} {<=} 1. For some inflated planets (WASP-6b and WASP-15b), we find fitting tracks; for another (TrES-4), we do not; and for others (WASP-4b and WASP-12b), we find fitting tracks, but our model might imply that we are observing the planets at a special time. Finally, we stress a 2-3 order

  13. Limits on the radius and a possible atmosphere of Charon from its 1980 stellar occultation

    NASA Technical Reports Server (NTRS)

    Elliot, J. L.; Young, L. A.

    1991-01-01

    Walker's (1980) stellar occultation data for Charon are presently fit by a model which encompasses the possibility of differential refraction by an atmosphere, followed by a sudden occultation behind Charon's limb. The 601.5-km Charon radius lower limit thus obtained may serve as a constraint in models of the mutual event data; while the model fits considered support a Charonian atmosphere of indeterminate composition, time resolution is insufficient for certainty and the data may be interpretable as indications of either a slight extinction near Charon or an entirely unidentified and unassociated effect.

  14. Every timelike geodesic in Anti-de Sitter spacetime is a circle of the same radius

    NASA Astrophysics Data System (ADS)

    Sokołowski, Leszek M.; Golda, Zdzisław A.

    2016-10-01

    In this paper, we refine and analytically prove an old proposition due to Calabi and Markus on the shape of timelike geodesics of anti-de Sitter space in the ambient flat space. We prove that each timelike geodesic forms in the ambient space a circle of the radius determined by Λ, lying on a Euclidean two-plane. Then, we outline an alternative proof for AdS4. We also make a comment on the shape of timelike geodesics in de Sitter space.

  15. Comments on finite Larmor radius models for ion cyclotron range of frequencies heating in tokamaks

    SciTech Connect

    Phillips, C.K.; Wilson, J.R.; Hosea, J.C.; Majeski, R.; Smithe, D.N.

    1994-06-01

    The accuracy of standard finite Larmor radius (FLR) models for wave propagation in the ion cyclotron range of frequencies (ICRF) is compared against full hot plasma models. For multiple ion species plasmas, the FLR model is shown to predict the presence of a spurious second harmonic ion-ion type resonance between the second harmonic cyclotron layers of two ion species. It is shown explicitly here that the spurious resonance is an artifact of the FLR models and that no absorption occurs in the plasma as a result of this ``resonance.``

  16. Inverse Radius of Biological Flocculus in the Reactor of the Water Decontamination

    NASA Astrophysics Data System (ADS)

    Liu, Ke-An; Wang, Xi-Lian; Han, Bo; Liu, Jia-Qi; Zhao, Hong-Bin

    2003-04-01

    The biological flocculus in the water disposing reactor can be treated as the spherical cell model. The biological flocculus grows with the time - the volume becomes big, the biological membrane becomes thick, the permeability becomes bad and the interior biophore dies so that to decrease the reactor's decontaminating ability. Properly controlling the volume of biological flocculus can improve the reactor's efficiency. The satisfactory radius of the biological flocculus is obtained by us of the finite-difference method, considering the properly controlling of biological flocculus volume as the mathematical inverse problem of geometrical boundary.

  17. Absence of Complete Finite-Larmor-Radius Stabilization in Extended MHD

    SciTech Connect

    Zhu, P.; Schnack, D. D.; Ebrahimi, F.; Zweibel, E. G.; Suzuki, M.; Hegna, C. C.; Sovinec, C. R.

    2008-08-22

    The dominant finite-Larmour-radius (FLR) stabilization effects on interchange instability can be retained by taking into account the ion gyroviscosity or the generalized Ohm's law in an extended MHD model. However, recent simulations and theoretical calculations indicate that complete FLR stabilization of the interchange mode may not be attainable by ion gyroviscosity or the two-fluid effect alone in the framework of extended MHD. For a class of plasma equilibria in certain finite-{beta} or nonisentropic regimes, the critical wave number for complete FLR stabilization tends toward infinity.

  18. Measurement of the Neutron Radius of 208Pb Through Parity-Violation in Electron Scattering

    DOE PAGES

    Abrahamyan, Sergey; Albataineh, Hisham; Aniol, Konrad; Armstrong, David; Armstrong, Whitney; Averett, Todd; Babineau, Benjamin; Barbieri, A.; Bellini, Vincenzo; Beminiwattha, Rakitha; et al

    2012-03-15

    We report the first measurement of the parity-violating asymmetry APV in the elastic scattering of polarized electrons from 208Pb. APV is sensitive to the radius of the neutron distribution (Rn). The result APV = 0.656 ± 0.060 (stat) ± 0.013 (syst) corresponds to a difference between the radii of the neutron and proton distributions Rn-Rp = 0.33-0.18+0.16 fm and provides the first electroweak observation of the neutron skin which is expected in a heavy, neutron-rich nucleus.

  19. Conservative Treatment Is Sufficient for Acute Distal Radioulnar Joint Instability With Distal Radius Fracture.

    PubMed

    Lee, Sang Ki; Kim, Kap Jung; Cha, Yong Han; Choy, Won Sik

    2016-09-01

    Treatments for acute distal radioulnar joint (DRUJ) instability with distal radius fracture vary from conservative to operative treatment, although it seems to be no consensus regarding which treatment is optimal. This prospective randomized study was designed to compare the clinical outcomes for operative and conservative treatment of acute DRUJ instability with distal radius fracture, according to the presence or absence and type of ulnar styloid process fracture and the degree of its displacement. Between July 2008 and February 2013, we enrolled 157 patients who exhibited an unstable DRUJ during intraoperative manual stress testing (via the ballottement test) after fixation of the distal radius. Patients were classified according to the type of the ulnar styloid process fracture, using preoperative wrist radiography, and each group was divided into subgroups, according to their treatment method. We then compared the clinical outcomes between the conservative and operative treatments, using their range of motion; Disabilities of the Arm, Shoulder, and Hand score; modified Mayo wrist score; and grip strength. At 3 months after surgery, among patients without ulnar styloid process fracture, the flexion-extension range was 79 ± 15° after supination sugar-tong splinting (group A-1), 91 ± 14° after DRUJ transfixation (group A-2), and 89 ± 10° after arthroscopic triangular fibrocartilage complex repair (group A-3); the operative treatments provided greater joint motion ranges than conservative treatment. The groups with ulnar styloid process fractures at the tip (group B) or base (group C) also exhibited better clinical outcomes after the operative treatments, compared with after the conservative treatment. However, at the final follow-up, groups A-1, A-2, and A-3 exhibited similar flexion-extension ranges (122 ± 25°, 119° ± 18°, and 120° ± 16°, respectively) and modified Mayo wrist scores (87 ± 7, 89 ± 8, and 85 ± 9). Thus, the conservative and

  20. Finite Larmor radius effects on the (m = 2, n = 1) cylindrical tearing mode

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Chowdhury, J.; Parker, S. E.; Wan, W.

    2015-04-01

    New field solvers are developed in the gyrokinetic code GEM [Chen and Parker, J. Comput. Phys. 220, 839 (2007)] to simulate low-n modes. A novel discretization is developed for the ion polarization term in the gyrokinetic vorticity equation. An eigenmode analysis with finite Larmor radius effects is developed to study the linear resistive tearing mode. The mode growth rate is shown to scale with resistivity as γ ˜ η1/3, the same as the semi-collisional regime in previous kinetic treatments [Drake and Lee, Phys. Fluids 20, 1341 (1977)]. Tearing mode simulations with gyrokinetic ions are verified with the eigenmode calculation.

  1. Replica-exchange method in van der Waals radius space: overcoming steric restrictions for biomolecules.

    PubMed

    Itoh, Satoru G; Okumura, Hisashi; Okamoto, Yuko

    2010-04-01

    We present a new type of the Hamiltonian replica-exchange method, where the van der Waals radius parameter and not the temperature is exchanged. By decreasing the van der Waals radii, which control spatial sizes of atoms, this Hamiltonian replica-exchange method overcomes the steric restrictions and energy barriers. Furthermore, the simulation based on this method escapes from the local-minimum free-energy states and realizes effective sampling in the conformational space. We applied this method to an alanine dipeptide in aqueous solution and showed the effectiveness of the method by comparing the results with those obtained from the conventional canonical and replica-exchange methods.

  2. Influence of Surface Radius Curvature on Laser Plasma Propulsion with Ablation Water Propellant

    NASA Astrophysics Data System (ADS)

    Liang, Tian; Zheng, Zhiyuan; Zhang, Siqi; Tang, Weichong; Xiao, Ke; Liang, Wenfei; Gao, Lu; Gao, Hua

    2016-10-01

    The surface shape of liquid water is well controlled during nanosecond pulse laser ablation plasma propulsion. In this study, we measured the effect of the shape on the coupling coefficient and the specific impulse. We found that the coupling coefficient and specific impulse could be optimized by varying the surface convexity. Based on the analysis of the surface radius curvature, we demonstrate that the convex surface changes the laser focal positions to achieve high efficiency. supported by National Natural Science Foundation of China (No. 10905049) and Fundamental Research Funds for the Central Universities of China (Nos. 53200859165, 2562010050)

  3. Fat drops in wrist tendon sheaths on MRI in conjunction with a radius fracture.

    PubMed

    Verhagen, Martijn V; Chesaru, Ileana

    2016-08-01

    A case is presented in which fat drops are seen on MRI inside extensor compartment 2 and 3, in conjunction with a radius fracture. The occurrence of traumatic tendon sheath fat-fluid levels has been sparsely reported on CT and MR imaging. This case is the first report of post-traumatic tendon sheath fat drops. Although the clinical relevance of tendon sheath fat drops seems to be limited, it is important to detect and correctly diagnose these fat drops in order to provide an accurate and complete radiologic report. PMID:27170371

  4. Jeans instability of magnetized quantum plasma: Effect of viscosity, rotation and finite Larmor radius corrections

    SciTech Connect

    Jain, Shweta Sharma, Prerana; Chhajlani, R. K.

    2015-07-31

    The Jeans instability of self-gravitating quantum plasma is examined considering the effects of viscosity, finite Larmor radius (FLR) corrections and rotation. The analysis is done by normal mode analysis theory with the help of relevant linearized perturbation equations of the problem. The general dispersion relation is obtained using the quantum magneto hydrodynamic model. The modified condition of Jeans instability is obtained and the numerical calculations have been performed to show the effects of various parameters on the growth rate of Jeans instability.

  5. New relationships connecting the dipole polarizability, radius, and second ionization potential for atoms.

    PubMed

    Hohm, Uwe; Thakkar, Ajit J

    2012-01-12

    The atomic dipole polarizability α of the 101 elements from He to No is related to the second ionization potential I₂ and the Waber-Cromer radius r(WC). Our recommended model is the function α = P₁·I₂⁻⁴ + P₂·r(WC)(3) I₂(y). With the parameters P₁ = 2.26, P₂ = 3.912, and y = 0.439, it reproduces the polarizabilities of all 101 elements with a mean absolute deviation of 7.5 au.

  6. Fast polarization-state tracking scheme based on radius-directed linear Kalman filter.

    PubMed

    Yang, Yanfu; Cao, Guoliang; Zhong, Kangping; Zhou, Xian; Yao, Yong; Lau, Alan Pak Tao; Lu, Chao

    2015-07-27

    We propose and experimentally demonstrate a fast polarization tracking scheme based on radius-directed linear Kalman filter. It has the advantages of fast convergence and is inherently insensitive to phase noise and frequency offset effects. The scheme is experimentally compared to conventional polarization tracking methods on the polarization rotation angular frequency. The results show that better tracking capability with more than one order of magnitude improvement is obtained in the cases of polarization multiplexed QPSK and 16QAM signals. The influences of the filter tuning parameters on tracking performance are also investigated in detail.

  7. Finite Larmor radius effects on the coupled trapped electron and ion temperature gradient modes

    SciTech Connect

    Sandberg, I.; Isliker, H.; Pavlenko, V. P.

    2007-09-15

    The properties of the coupled trapped electron and toroidal ion temperature gradient modes are investigated using the standard reactive fluid model and taking rigorously into account the effects attributed to the ion polarization drift and to the drifts associated with the lowest-order finite ion Larmor radius effects. In the flat density regime, where the coupling between the modes is relatively weak, the properties of the unstable modes are slightly modified through these effects. For the peak density regions, where the coupling of the modes is rather strong, these second-order drifts determine the spectra of the unstable modes near the marginal conditions.

  8. Modeling the Impact of Drizzle and 3D Cloud Structure on Remote Sensing of Effective Radius

    NASA Technical Reports Server (NTRS)

    Platnick, Steven; Zinner, Tobias; Ackerman, S.

    2008-01-01

    Remote sensing of cloud particle size with passive sensors like MODIS is an important tool for cloud microphysical studies. As a measure of the radiatively relevant droplet size, effective radius can be retrieved with different combinations of visible through shortwave infrared channels. MODIS observations sometimes show significantly larger effective radii in marine boundary layer cloud fields derived from the 1.6 and 2.1 pm channel observations than for 3.7 pm retrievals. Possible explanations range from 3D radiative transport effects and sub-pixel cloud inhomogeneity to the impact of drizzle formation on the droplet distribution. To investigate the potential influence of these factors, we use LES boundary layer cloud simulations in combination with 3D Monte Carlo simulations of MODIS observations. LES simulations of warm cloud spectral microphysics for cases of marine stratus and broken stratocumulus, each for two different values of cloud condensation nuclei density, produce cloud structures comprising droplet size distributions with and without drizzle size drops. In this study, synthetic MODIS observations generated from 3D radiative transport simulations that consider the full droplet size distribution will be generated for each scene. The operational MODIS effective radius retrievals will then be applied to the simulated reflectances and the results compared with the LES microphysics.

  9. Postexercise and positional variation in mechanical properties of the radius in young horses.

    PubMed

    Batson, E L; Reilly, G C; Currey, J D; Balderson, D S

    2000-03-01

    The metacarpal of the horse is severely loaded during vigorous exercise. Metacarpal specimens have a greater impact strength in young horses that have been exercised than in those that have only been walked. We did not find a corresponding difference in the radius of the same horses. We show that cranial (anterior) cortical bone from the radius, which is loaded in tension during locomotion, has a greater Young's modulus, and tensile and bending strength, than bone from the caudal (posterior) cortex, which is loaded in compression. Caudal bone is, however, stronger in compression. The differences can be explained by differences in the histological structure developed by the 2 cortices and are presumably adaptive. This work confirms the work of others. Furthermore, we demonstrate that the impact energy absorption of cranial bone is nearly twice as great as that of caudal bone. The caudal cortex has apparently paid a heavy price in its reduction in resistance to accidental impact loading for being stronger than the cranial cortex in compressive loading.

  10. MEASURING THE SOLAR RADIUS FROM SPACE DURING THE 2003 AND 2006 MERCURY TRANSITS

    SciTech Connect

    Emilio, M.; Kuhn, J. R.; Scholl, I. F.; Bush, R. I. E-mail: kuhn@ifa.hawaii.edu E-mail: rock@sun.stanford.edu

    2012-05-10

    The Michelson Doppler Imager (MDI) aboard the Solar and Heliospheric Observatory observed the transits of Mercury on 2003 May 7 and 2006 November 8. Contact times between Mercury and the solar limb have been used since the seventeenth century to derive the Sun's size but this is the first time that high-quality imagery from space, above the Earth's atmosphere, has been available. Unlike other measurements, this technique is largely independent of optical distortion. The true solar radius is still a matter of debate in the literature as measured differences of several tenths of an arcsecond (i.e., about 500 km) are apparent. This is due mainly to systematic errors from different instruments and observers since the claimed uncertainties for a single instrument are typically an order of magnitude smaller. From the MDI transit data we find the solar radius to be 960.''12 {+-} 0.''09 (696, 342 {+-} 65 km). This value is consistent between the transits and consistent between different MDI focus settings after accounting for systematic effects.

  11. The Mass-Radius Relation of Young Stars from K2

    NASA Astrophysics Data System (ADS)

    Kraus, Adam L.; Cody, Ann Marie; Covey, Kevin R.; Rizzuto, Aaron C.; Mann, Andrew; Ireland, Michael; Jensen, Eric L. N.; Muirhead, Philip Steven

    2016-01-01

    Evolutionary models of pre-main sequence stars remain largely uncalibrated, especially for masses below that of the Sun, and dynamical masses and radii pose valuable tests of these theoretical models. Stellar mass dependent features of star formation (such as disk evolution, planet formation, and even the IMF) are fundamentally tied to these models, which implies a systematic uncertainty that can only be improved with precise measurements of calibrator stars. We will describe the discovery and characterization of ten eclipsing binary systems in the Upper Scorpius star-forming region from K2 Campaign 2 data, spanning from B stars to the substellar boundary. We have obtained complementary RV curves, spectral classifications, and high-resolution imaging for these targets; the combination of these data yield high-precision masses and radii for the binary components, and hence a dense sampling of the (nominally coeval) mass-radius relation of 10 Myr old stars. We already reported initial results from this program for the young M4.5 eclipsing binary UScoCTIO 5 (Kraus et al. 2015), demonstrating that theoretically predicted masses are discrepant by ~50% for low-mass stars. K2's unique radius measurements allow us to isolate the source of the discrepancy: models of young stars do not predict luminosities that are too low, as is commonly thought, but rather temperatures that are too warm.

  12. Type IIA Monteggia Fracture Dislocation with Ipsilateral Distal Radius Fracture in Adult – A Rare Association

    PubMed Central

    James, Boblee

    2016-01-01

    Monteggia fracture constitutes about 5-10% of the forearm fractures. Monteggia fracture by definition is proximal ulnar fracture with disruption of proximal radioulnar joint. Bado classified Monteggia fracture dislocation into four types and Jupiter subclassified type II Bado’s fractures into four types. The associated injury in the form of distal radial fractures and distal humerus fractures are rare though many cases of distal radial physeal injuries have been reported in paediatric population. Hereby we report a rare association of type IIA Monteggia fracture dislocation with ipsilateral distal radius fracture in an adult patient. This case report also highlights on proper examination and full length radiographs of forearm to avoid missing injury at wrist in cases of elbow injuries. Management of such complex injuries included open reduction and internal fixation of olecronon fracture, distal radius fracture and radial head resection. Functional outcome at six months was good at wrist whereas at elbow, stiffness was a major concern with elbow range of movement from 40°-110°. PMID:27656518

  13. Type IIA Monteggia Fracture Dislocation with Ipsilateral Distal Radius Fracture in Adult - A Rare Association.

    PubMed

    Kembhavi, Raghavendra S; James, Boblee

    2016-08-01

    Monteggia fracture constitutes about 5-10% of the forearm fractures. Monteggia fracture by definition is proximal ulnar fracture with disruption of proximal radioulnar joint. Bado classified Monteggia fracture dislocation into four types and Jupiter subclassified type II Bado's fractures into four types. The associated injury in the form of distal radial fractures and distal humerus fractures are rare though many cases of distal radial physeal injuries have been reported in paediatric population. Hereby we report a rare association of type IIA Monteggia fracture dislocation with ipsilateral distal radius fracture in an adult patient. This case report also highlights on proper examination and full length radiographs of forearm to avoid missing injury at wrist in cases of elbow injuries. Management of such complex injuries included open reduction and internal fixation of olecronon fracture, distal radius fracture and radial head resection. Functional outcome at six months was good at wrist whereas at elbow, stiffness was a major concern with elbow range of movement from 40°-110°. PMID:27656518

  14. Measurement of humerus and radius bone mineral content in the term and preterm infant

    SciTech Connect

    Vyhmeister, N.R.; Linkhart, T.A.

    1988-07-01

    We compared two anatomic sites for single-photon absorptiometric measurement of bone mineral content (BMC) in term and preterm infants. The distal one third of the radius and the midportion of the humerus were evaluated for measurements of BMC with an unmodified, commercially available bone densitometer. We assessed reproducibility of BMC and bone width (BW) measurements and defined normal at-birth ranges of BMC, BW, and BMC/BW ratio for infants with gestational ages of 24 to 42 weeks. Humerus BMC correlated with gestational age, birth weight, and BW of patients and did not differ from humerus BMC values determined over the same range of gestational ages at another center. Representative serial measurements of two very low birth weight (VLBW) infants are presented to demonstrate the feasibility of using humerus BMC in longitudinal studies to assess changes in bone mineralization. We conclude that bone densitometer measurements of mid-humerus BMC can be successfully performed and are preferable to similar measurements of the radius for VLBW infants. Normal humerus BMC values were defined for use in diagnosis and evaluation of the efficacy of treatment in VLBW infants who are at high risk of developing osteopenia of prematurity.

  15. Low Velocity Impacts of Variable Tip Radius on Carbon/Epoxy Plates

    NASA Astrophysics Data System (ADS)

    Delaney, Mac P.

    With a growing use of composite materials in aircraft structures, there is a greater need to understand the response of these materials to low velocity impacts. Low velocity impacts from tool drops or ground equipment collisions can be of varying bluntness and can leave little or no visible evidence of damage. Therefore, a need exists to investigate the initiation of internal damage and the relationship between this internal damage and the external visible damage with respect to the bluntness of the impactor. A pendulum impactor was used to impact 76.2 x 127 mm carbon/epoxy panels that were 8, 16, and 24 plies thick. The panels were impacted by hardened steel tips with radii of 12.7 to 76.2 mm. The experimental results show that the failure threshold energies for each panel thickness and tip radius combination occur at a distinct and consistent energy. This threshold increases with impactor bluntness, and this effect is greater for the 8 ply panel than it is for the 16 or 24 ply panels. To describe the visibility of impact damage, the area of delamination was compared to the depth of the dents resulting from the impacts. For the sharper impact tips, there is a clear relationship between the delamination area and the depth of the dents. However, these relationships are dependent on the radius of the impact tip, and for the blunter impact tips no strong correlation could be determined between the delamination area and the depth of the dents.

  16. Free-jet acoustic investigation of high-radius-ratio coannular plug nozzles

    NASA Technical Reports Server (NTRS)

    Knott, P. R.; Janardan, B. A.; Majjigi, R. K.; Bhutiani, P. K.; Vogt, P. G.

    1984-01-01

    The experimental and analytical results of a scale model simulated flight acoustic exploratory investigation of high radius ratio coannular plug nozzles with inverted velocity and temperature profiles are summarized. Six coannular plug nozzle configurations and a baseline convergent conical nozzle were tested for simulated flight acoustic evaluation. The nozzles were tested over a range of test conditions that are typical of a Variable Cycle Engine for application to advanced high speed aircraft. It was found that in simulate flight, the high radius ratio coannular plug nozzles maintain their jet noise and shock noise reduction features previously observed in static testing. The presence of nozzle bypass struts will not significantly affect the acousticn noise reduction features of a General Electric type nozzle design. A unique coannular plug nozzle flight acoustic spectral prediction method was identified and found to predict the measured results quite well. Special laser velocimeter and acoustic measurements were performed which have given new insights into the jet and shock noise reduction mechanisms of coannular plug nozzles with regard to identifying further benificial research efforts.

  17. A fluid finite ion Larmor radius model of the magnetopause layer

    SciTech Connect

    Stasiewicz, K. )

    1989-07-01

    A model of the magnetopause current layer is constructed on the basis of fluid equations for collision-free plasmas with finite ion Larmor radius (FLR). The model provides self-consistent solutions for the plasma flow vector, magnetic field, and electric currents inside the magnetopause layer. This is the first fluid model that offers explanations for some observations at the terrestrial magnetopause that are inexplicable by earlier models. In particular, it is shown that the erosion of the dayside magnetosphere can be explained by the normal component of the gyroviscous stress tensor that is related to the intensity of field-aligned currents inside the magnetopause layer. It is found that the sense of rotation of the magnetic field across the magnetopause is determined by the ratio of the normal component of the Alfven velocity to the normal flow velocity {xi}={ital B}{sub {ital n}}/({mu}{sub 0}{rho}){sup 1/2}{ital V}{sub {ital n}}. For {vert bar} {xi} {vert bar}{gt}1 the sense of rotation corresponds to electron polarization, and {vert bar} {xi} {vert bar}{lt}1 yields proton polarization. It is argued that the case {vert bar} {xi} {vert bar}=1 corresponds to the formation of transient flux transfer events. The observed departures from MHD jump conditions across the magnetopause are explained by additional, finite Larmor radius terms in the moment equations. An expression is also derived for the characteristic thickness of the magnetopause layer. {copyright} American Geophysical Union 1989

  18. Polymer microlens with independent control of radius and focal length for an imaging fiber

    NASA Astrophysics Data System (ADS)

    Ashraf, Mohammed; Chollet, Franck; Matham, Murukeshan; Yang, Chun

    2006-01-01

    Fabrication of microlens array using polymer reflow is beginning to be a mainstream process, whether the polymer is directly used or whether the spherical profile is transferred by plasma etching to a glass substrate as, for example, in some handphone cameras. The focus so far has been on uniformity and obtaining lenses with equal radius and equal focal length. Actually it is easy to show using a phenomenological model that the focal length is depending on the lens radius, and not much on the contact angle, an effect that can be traced to the line tension force. For a biomedical application we need to terminate a 600um diameter imaging fiber with a group of lenses of different diameters - but with similar focal length. We have devised a microfabrication process on a silicon wafer to produce the lens with variable diameter and identical focal length, while etching the silicon wafer has helped us producing a sheath to insert the optical fiber and mount the lenses on the optical fiber.

  19. TRACING THE GAS TO THE VIRIAL RADIUS (R{sub 100}) IN A FOSSIL GROUP

    SciTech Connect

    Humphrey, Philip J.; Buote, David A.; Flohic, Helene M. L. G.; Gastaldello, Fabio; Brighenti, Fabrizio; Mathews, William G.

    2012-03-20

    We present a Chandra, Suzaku, and ROSAT study of the hot intragroup medium (IGrM) of the relaxed fossil group/poor cluster RX J1159+5531. This group exhibits an advantageous combination of flat surface brightness profile, high luminosity, and optimal distance, allowing the gas to be detected out to the virial radius (R{sub vir}{identical_to} R{sub 108} = 1100 kpc) in a single Suzaku pointing, while the complementary Chandra data reveal a round morphology and relaxed IGrM image down to kpc scales. We measure the IGrM entropy profile over {approx}3 orders of magnitude in radius, including three data bins beyond {approx}0.5R{sub 200} that have good azimuthal coverage (>30%). We find no evidence that the profile flattens at large scales (>R{sub 500}), and when corrected for the enclosed gas fraction, the entropy profile is very close to the predictions from self-similar structure formation simulations, as seen in massive clusters. Within R{sub vir}, we measure a baryon fraction of 0.17 {+-} 0.02, consistent with the cosmological value. These results are in sharp contrast to the gas behavior at large scales recently reported in the Virgo and Perseus clusters and indicate that substantial gas clumping cannot be ubiquitous near R{sub vir}, at least in highly evolved (fossil) groups.

  20. Pinhole Solar Monitor to Detect 0.01”RADIUS Variations

    NASA Astrophysics Data System (ADS)

    Sigismondi, Costantino; Contento, Carla

    The Pinhole Solar Monitor (PSM) is a small space-device with two pinholes projecting two identical images on the focal plane. It has the advantage to be an astigmatic heliometer without optics compact without need of accurate pointing and costless. On the payload of a satellite PSM exploits the side facing the Sun and monitors the secular variations of the angular solar diameter D. Two pinholes of equal radius r are built on the same rigid platform at distance d between the centers; they project two images on the focal plane a flat screen parallel to the platform at distance f. When those images are in contact tan(D)=d/f. The contact between the two solar limbs is simulated with a raytracer and studied numerically. The focal length of contact about 1 meter can be measured with a system of encoder-actuators within 10 micron of precision. Although d and r are measurable within a micron of accuracy they introduce errors in the calculation of D which are systematic due to thermal stability in the space. With such a compact device an accuracy of 0.01 arcseconds is expected evaluating the variations of the mean angular solar radius D/2~960 arcseconds.

  1. Galaxies as Clocks: the Radius -- Velocity Relationship of HI Rich Galaxies

    NASA Astrophysics Data System (ADS)

    Meurer, Gerhardt; Obreschkow, D.; Hanish, D.; Wong, O.; Zheng, Z.; de Blok, E.; Thilker, D. A.; SINGG Team; SUNGG Team

    2014-01-01

    We show that the outskirts of HI rich galaxies obey a linear radius (R) versus rotational velocity (Vrot) relationship. This means they behave like clocks: they have the same orbital time of ~800 Myr. The relationship is valid over the full range for which we have data - a factor of 30 from dwarf galaxies with R ~ 1 kpc and Vrot ~ 10 km/s to giant spirals with R = 30 kpc and Vrot = 300 km/s with an intrinsic scatter smaller than 40%. A linear R -- Vrot relationship is expected for Cold Dark Matter (CDM) dominated halos. The fact that the collapsed baryons of disk galaxies obey this relationship can be readily understood within the CDM paradigm. We show what is required for the situation to occur. The mean density within the outer radius is 3e-3 Msun/pc^3, requiring that the baryonic component of disk galaxies to have collapsed by a factor of ~40. We outline the practical uses of the relationship and the implications for galaxy evolution.

  2. RADIUS-DEPENDENT ANGULAR MOMENTUM EVOLUTION IN LOW-MASS STARS. I

    SciTech Connect

    Reiners, Ansgar; Mohanty, Subhanjoy

    2012-02-10

    Angular momentum evolution in low-mass stars is determined by initial conditions during star formation, stellar structure evolution, and the behavior of stellar magnetic fields. Here we show that the empirical picture of angular momentum evolution arises naturally if rotation is related to magnetic field strength instead of to magnetic flux and formulate a corrected braking law based on this. Angular momentum evolution then becomes a strong function of stellar radius, explaining the main trends observed in open clusters and field stars at a few Gyr: the steep transition in rotation at the boundary to full convection arises primarily from the large change in radius across this boundary and does not require changes in dynamo mode or field topology. Additionally, the data suggest transient core-envelope decoupling among solar-type stars and field saturation at longer periods in very low mass stars. For solar-type stars, our model is also in good agreement with the empirical Skumanich law. Finally, in further support of the theory, we show that the predicted age at which low-mass stars spin down from the saturated to unsaturated field regimes in our model corresponds remarkably well to the observed lifetime of magnetic activity in these stars.

  3. A Precise Asteroseismic Age and Radius for the Evolved Sun-like Star KIC 11026764

    NASA Astrophysics Data System (ADS)

    Metcalfe, T. S.; Monteiro, M. J. P. F. G.; Thompson, M. J.; Molenda-Żakowicz, J.; Appourchaux, T.; Chaplin, W. J.; Doǧan, G.; Eggenberger, P.; Bedding, T. R.; Bruntt, H.; Creevey, O. L.; Quirion, P.-O.; Stello, D.; Bonanno, A.; Silva Aguirre, V.; Basu, S.; Esch, L.; Gai, N.; Di Mauro, M. P.; Kosovichev, A. G.; Kitiashvili, I. N.; Suárez, J. C.; Moya, A.; Piau, L.; García, R. A.; Marques, J. P.; Frasca, A.; Biazzo, K.; Sousa, S. G.; Dreizler, S.; Bazot, M.; Karoff, C.; Frandsen, S.; Wilson, P. A.; Brown, T. M.; Christensen-Dalsgaard, J.; Gilliland, R. L.; Kjeldsen, H.; Campante, T. L.; Fletcher, S. T.; Handberg, R.; Régulo, C.; Salabert, D.; Schou, J.; Verner, G. A.; Ballot, J.; Broomhall, A.-M.; Elsworth, Y.; Hekker, S.; Huber, D.; Mathur, S.; New, R.; Roxburgh, I. W.; Sato, K. H.; White, T. R.; Borucki, W. J.; Koch, D. G.; Jenkins, J. M.

    2010-11-01

    The primary science goal of the Kepler Mission is to provide a census of exoplanets in the solar neighborhood, including the identification and characterization of habitable Earth-like planets. The asteroseismic capabilities of the mission are being used to determine precise radii and ages for the target stars from their solar-like oscillations. Chaplin et al. published observations of three bright G-type stars, which were monitored during the first 33.5 days of science operations. One of these stars, the subgiant KIC 11026764, exhibits a characteristic pattern of oscillation frequencies suggesting that it has evolved significantly. We have derived asteroseismic estimates of the properties of KIC 11026764 from Kepler photometry combined with ground-based spectroscopic data. We present the results of detailed modeling for this star, employing a variety of independent codes and analyses that attempt to match the asteroseismic and spectroscopic constraints simultaneously. We determine both the radius and the age of KIC 11026764 with a precision near 1%, and an accuracy near 2% for the radius and 15% for the age. Continued observations of this star promise to reveal additional oscillation frequencies that will further improve the determination of its fundamental properties.

  4. RADIUS CONSTRAINTS AND MINIMAL EQUIPARTITION ENERGY OF RELATIVISTICALLY MOVING SYNCHROTRON SOURCES

    SciTech Connect

    Barniol Duran, Rodolfo; Piran, Tsvi; Nakar, Ehud E-mail: tsvi.piran@mail.huji.ac.il

    2013-07-20

    A measurement of the synchrotron self-absorption flux and frequency provides tight constraints on the physical size of the source and a robust lower limit on its energy. This lower limit is also a good estimate of the magnetic field and electrons' energy, if the two components are at equipartition. This well-known method was used for decades to study numerous astrophysical sources moving at non-relativistic (Newtonian) speeds. Here, we generalize the Newtonian equipartition theory to sources moving at relativistic speeds including the effect of deviation from spherical symmetry expected in such sources. As in the Newtonian case, minimization of the energy provides an excellent estimate of the emission radius and yields a useful lower limit on the energy. We find that the application of the Newtonian formalism to a relativistic source would yield a smaller emission radius, and would generally yield a larger lower limit on the energy (within the observed region). For sources where the synchrotron-self-Compton component can be identified, the minimization of the total energy is not necessary and we present an unambiguous solution for the parameters of the system.

  5. Chondroblastoma of Diaphysis of Radius in a Seven Year Old Child

    PubMed Central

    Punit, Abhinandan; Nadkarni, Sambaprasad; Doomra, Tanvir

    2014-01-01

    Introduction: Chondroblastoma is a rare, benign tumor derived from chondroblasts, is almost exclusively an epiphyseal lesion, although it may secondarily extend into metaphysis. It is most commonly found in lower extremity with most common sites being distal femur followed by proximal femur, proximal humerus and proximal tibia. It is the purpose of the report to describe chondroblastoma in a seven year old child in the diaphyseal area of radius which is a rare entity & frequently presents as diagnostic dilemma. Case Report: The authors report a case of chondroblastoma involving the diaphyseal area of radius in a seven year old female child. She presented with pain and swelling around the left distal third forearm for eight months. Wide excision of tumor was performed and the defect was bridged with avascular fibular auto graft, secured to host bone with k-wires and dynamic compression plate to achieve osteosynthesis. Conclusion: Pure metaphyseal and/or diaphyseal chondroblastomas are exceedingly rare. A presumptive diagnosis may be considered in the appropriate age group in the presence of chondroid matrix, perilesional edema, periosteal reaction, and marginal sclerosis. Regardless of all the diagnostic possibilities biopsy may still be required. However, knowledge of this entity will help make the final diagnosis and guide the correct treatment. PMID:27298978

  6. Solar cycle dependence of the sun's radius at lambda = 525.0 nm

    NASA Technical Reports Server (NTRS)

    Ulrich, Roger K.; Bertello, L.

    1995-01-01

    The Mount Wilson (California) synoptic program of solar magnetic observations scans the solar disk between 1 and 20 times per day. As part of this program, the radius is determined as an average distance between the image center and the point where the intensity in the FeI line at lambda = 525.0 nm drops to 25 percent of its value at the disk's center. The data base of information was analyzed and corrected for effects such as scattered light and atmospheric reflection. The solar variability and the measurement techniques are described. The observation data sets, the corrections made to the data, and the observed variations, are discussed. It is stated that similar spectral lines at lambda = 525.0 nm, which are common in the solar spectrum, probably exhibit similar radius changes. All portions of the sun are weighted equally so that it is concluded that, within spectral lines, the radiating area of the sun is increased at the solar maximum.

  7. Hummingbirds control turning velocity using body orientation and turning radius using asymmetrical wingbeat kinematics.

    PubMed

    Read, Tyson J G; Segre, Paolo S; Middleton, Kevin M; Altshuler, Douglas L

    2016-03-01

    Turning in flight requires reorientation of force, which birds, bats and insects accomplish either by shifting body position and total force in concert or by using left-right asymmetries in wingbeat kinematics. Although both mechanisms have been observed in multiple species, it is currently unknown how each is used to control changes in trajectory. We addressed this problem by measuring body and wingbeat kinematics as hummingbirds tracked a revolving feeder, and estimating aerodynamic forces using a quasi-steady model. During arcing turns, hummingbirds symmetrically banked the stroke plane of both wings, and the body, into turns, supporting a body-dependent mechanism. However, several wingbeat asymmetries were present during turning, including a higher and flatter outer wingtip path and a lower more deviated inner wingtip path. A quasi-steady analysis of arcing turns performed with different trajectories revealed that changes in radius were associated with asymmetrical kinematics and forces, and changes in velocity were associated with symmetrical kinematics and forces. Collectively, our results indicate that both body-dependent and -independent force orientation mechanisms are available to hummingbirds, and that these kinematic strategies are used to meet the separate aerodynamic challenges posed by changes in velocity and turning radius.

  8. A SCALING RELATION BETWEEN MEGAMASER DISK RADIUS AND BLACK HOLE MASS IN ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Wardle, Mark; Yusef-Zadeh, Farhad E-mail: zadeh@northwestern.edu

    2012-05-10

    Several thin, Keplerian, sub-parsec megamaser disks have been discovered in the nuclei of active galaxies and used to precisely determine the mass of their host black holes. We show that there is an empirical linear correlation between the disk radius and the black hole mass. We demonstrate that such disks are naturally formed by the partial capture of molecular clouds passing through the galactic nucleus and temporarily engulfing the central supermassive black hole. Imperfect cancellation of the angular momenta of the cloud material colliding after passing on opposite sides of the hole leads to the formation of a compact disk. The radial extent of the disk is determined by the efficiency of this process and the Bondi-Hoyle capture radius of the black hole, and naturally produces the empirical linear correlation of the radial extent of the maser distribution with black hole mass. The disk has sufficient column density to allow X-ray irradiation from the central source to generate physical and chemical conditions conducive to the formation of 22 GHz H{sub 2}O masers. For initial cloud column densities {approx}< 10{sup 23.5} cm{sup -2} the disk is non-self-gravitating, consistent with the ordered kinematics of the edge-on megamaser disks; for higher cloud columns the disk would fragment and produce a compact stellar disk similar to that observed around Sgr A* at the galactic center.

  9. The Mass-Radius-Eccentricity Distribution of Near-Resonant Transiting Exoplanet Pairs Detected by Kepler

    NASA Astrophysics Data System (ADS)

    Shabram, Megan; Jontof-Hutter, Daniel; Ford, Eric B.

    2015-12-01

    We characterize the mass-radius-eccentricity distribution of transiting planets near first-order mean motion resonances using Transit Timing Variation (TTV) observations from NASA's Kepler mission. Kepler's precise measurements of transit times (Mazeh et al. 2014; Rowe et al. 2015) constrain the planet-star mass ratio, eccentricity and pericenter directions for hundreds of planets. Strongly-interacting planetary systems allow TTVs to provide precise measurements of masses and orbital eccentricities separately (e.g., Kepler-36, Carter et al. 2012). In addition to these precisely characterized planetary systems, there are several systems harboring at least two planets near a mean motion resonance (MMR) for which TTVs provide a joint constraint on planet masses, eccentricities and pericenter directions (Hadden et al. 2015). Unfortunately, a near degeneracy between these parameters leads to a posterior probability density with highly correlated uncertainties. Nevertheless, the population encodes valuable information about the distribution of planet masses, orbital eccentricities and the planet mass-radius relationship. We characterize the distribution of masses and eccentricities for near-resonant transiting planets by combining a hierarchical Bayesian model with an analytic model for the TTV signatures of near-resonant planet pairs (Lithwick & Wu 2012). By developing a rigorous statistical framework for analyzing the TTV signatures of a population of planetary systems, we significantly improve upon previous analyses. For example, our analysis includes transit timing measurements of near-resonant transiting planet pairs regardless of whether there is a significant detection of TTVs, thereby avoiding biases due to only including TTV detections.

  10. Sensitivity bias in the mass-radius distribution from transit timing variations and radial velocity measurements

    NASA Astrophysics Data System (ADS)

    Steffen, Jason H.

    2016-04-01

    Motivated by recent discussions, both in private and in the literature, we use a Monte Carlo simulation of planetary systems to investigate sources of bias in determining the mass-radius distribution of exoplanets for the two primary techniques used to measure planetary masses - radial velocities (RVs) and transit timing variations (TTVs). We assert that mass measurements derived from these two methods are comparably reliable - as the physics underlying their respective signals is well understood. Nevertheless, their sensitivity to planet mass varies with the properties of the planets themselves. We find that for a given planet size, the RV method tends to find planets with higher mass while the sensitivity of TTVs is more uniform. This `sensitivity bias' implies that a complete census of TTV systems is likely to yield a more robust estimate of the mass-radius distribution provided there are not important physical differences between planets near and far from mean-motion resonance. We discuss differences in the sensitivity of the two methods with orbital period and system architecture, which may compound the discrepancies between them (e.g. short-period planets detectable by RVs may be more dense due to atmospheric loss). We advocate for continued mass measurements using both approaches as a means both to measure the masses of more planets and to identify potential differences in planet structure that may result from their dynamical and environmental histories.

  11. A PRECISE ASTEROSEISMIC AGE AND RADIUS FOR THE EVOLVED SUN-LIKE STAR KIC 11026764

    SciTech Connect

    Metcalfe, T. S.; Monteiro, M. J. P. F. G.; Thompson, M. J.; Molenda-Zakowicz, J.; Appourchaux, T.; Chaplin, W. J.; Dogan, G.; Eggenberger, P.; Bedding, T. R.; Stello, D.; Bruntt, H.; Creevey, O. L.; Quirion, P.-O.; Bonanno, A.; Silva Aguirre, V.; Basu, S.; Esch, L.; Gai, N.; Di Mauro, M. P.; Kosovichev, A. G.

    2010-11-10

    The primary science goal of the Kepler Mission is to provide a census of exoplanets in the solar neighborhood, including the identification and characterization of habitable Earth-like planets. The asteroseismic capabilities of the mission are being used to determine precise radii and ages for the target stars from their solar-like oscillations. Chaplin et al. published observations of three bright G-type stars, which were monitored during the first 33.5 days of science operations. One of these stars, the subgiant KIC 11026764, exhibits a characteristic pattern of oscillation frequencies suggesting that it has evolved significantly. We have derived asteroseismic estimates of the properties of KIC 11026764 from Kepler photometry combined with ground-based spectroscopic data. We present the results of detailed modeling for this star, employing a variety of independent codes and analyses that attempt to match the asteroseismic and spectroscopic constraints simultaneously. We determine both the radius and the age of KIC 11026764 with a precision near 1%, and an accuracy near 2% for the radius and 15% for the age. Continued observations of this star promise to reveal additional oscillation frequencies that will further improve the determination of its fundamental properties.

  12. Design-Optimization and Material Selection for a Proximal Radius Fracture-Fixation Implant

    NASA Astrophysics Data System (ADS)

    Grujicic, M.; Xie, X.; Arakere, G.; Grujicic, A.; Wagner, D. W.; Vallejo, A.

    2010-11-01

    The problem of optimal size, shape, and placement of a proximal radius-fracture fixation-plate is addressed computationally using a combined finite-element/design-optimization procedure. To expand the set of physiological loading conditions experienced by the implant during normal everyday activities of the patient, beyond those typically covered by the pre-clinical implant-evaluation testing procedures, the case of a wheel-chair push exertion is considered. Toward that end, a musculoskeletal multi-body inverse-dynamics analysis is carried out of a human propelling a wheelchair. The results obtained are used as input to a finite-element structural analysis for evaluation of the maximum stress and fatigue life of the parametrically defined implant design. While optimizing the design of the radius-fracture fixation-plate, realistic functional requirements pertaining to the attainment of the required level of the devise safety factor and longevity/lifecycle were considered. It is argued that the type of analyses employed in the present work should be: (a) used to complement the standard experimental pre-clinical implant-evaluation tests (the tests which normally include a limited number of daily-living physiological loading conditions and which rely on single pass/fail outcomes/decisions with respect to a set of lower-bound implant-performance criteria) and (b) integrated early in the implant design and material/manufacturing-route selection process.

  13. The Utility of the Fluoroscopic Skyline View During Volar Locking Plate Fixation of Distal Radius Fractures

    PubMed Central

    Vaiss, Lucile; Ichihara, Satoshi; Hendriks, Sarah; Taleb, Chihab; Liverneaux, Philippe; Facca, Sybille

    2014-01-01

    Background Open reduction and internal fixation (ORIF) using a volar locking plate is a common method for treating displaced distal radius fractures. There is, however, the risk of extensor tendon rupture due to protrusion of the screw tips past the dorsal cortex, which cannot always be adequately seen on a lateral fluoroscopic view. We therefore wished to compare the sensitivity of an intraoperative fluoroscopic skyline view to a lateral fluorosocopic view in detecting past pointing of these screws. Material and Methods Our series included 75 patients with an average age of 59 years who underwent volar locked plate fixation of a displaced distal radius fracture. Intraoperative anteroposterior (AP), lateral, and skyline fluoroscopic views were performed in each case. The number of screws that were seen to protrude past the dorsal cortex of the distal fracture fragment were recorded for both the lateral and skyline views. The number of screws that required exchange was also documented. Results No screws were seen to protrude past the dorsal cortical bone on the lateral fluroscopic views. 15 of 300 screws (5%) were seen to protrude past the dorsal cortex by an average of 0.8 mm (range, 0.5 to 2 mm) and were exchanged for shorter screws in 11/75 patients. Conclusion Our results demonstrate that the skyline is more sensitive than a lateral fluoroscopic view at demonstrating protrusion of the screws in the distal fracture fragment following volar locked plate fixation. Level of Evidence IV PMID:25364637

  14. Charon's radius and atmospheric constraints from observations of a stellar occultation.

    PubMed

    Gulbis, A A S; Elliot, J L; Person, M J; Adams, E R; Babcock, B A; Emilio, M; Gangestad, J W; Kern, S D; Kramer, E A; Osip, D J; Pasachoff, J M; Souza, S P; Tuvikene, T

    2006-01-01

    The physical characteristics of Pluto and its moon, Charon, provide insight into the evolution of the outer Solar System. Although previous measurements have constrained the masses of these bodies, their radii and densities have remained uncertain. The observation of a stellar occultation by Charon in 1980 established a lower limit on its radius of 600 km (ref. 3) (later refined to 601.5 km; ref. 4) and suggested a possible atmosphere. Subsequent, mutual event modelling yielded a range of 600-650 km (ref. 5), corresponding to a density of 1.56 +/- 0.22 g cm(-3) (refs 2, 5). Here we report multiple-station observations of a stellar occultation by Charon. From these data, we find a mean radius of 606 +/- 8 km, a bulk density of 1.72 +/- 0.15 g cm(-3), and rock-mass fraction 0.63 +/- 0.05. We do not detect a significant atmosphere and place 3sigma upper limits on atmospheric number densities for candidate gases. These results seem to be consistent with collisional formation for the Pluto-Charon system in which the precursor objects may have been differentiated, and they leave open the possibility of atmospheric retention by the largest objects in the outer Solar System.

  15. M DWARF LUMINOSITY, RADIUS, AND α-ENRICHMENT FROM I-BAND SPECTRAL FEATURES

    SciTech Connect

    Terrien, Ryan C.; Mahadevan, Suvrath; Bender, Chad F.; Deshpande, Rohit; Robertson, Paul

    2015-03-20

    Despite the ubiquity of M dwarfs and their growing importance to studies of exoplanets, Galactic evolution, and stellar structure, methods for precisely measuring their fundamental stellar properties remain elusive. Existing techniques for measuring M dwarf luminosity, mass, radius, or composition are calibrated over a limited range of stellar parameters or require expensive observations. We find a strong correlation between the K{sub S}-band luminosity (M{sub K}), the observed strength of the I-band sodium doublet absorption feature, and [Fe/H] in M dwarfs without strong Hα emission. We show that the strength of this feature, coupled with [Fe/H] and spectral type, can be used to derive M dwarf M{sub K} and radius without requiring parallax. Additionally, we find promising evidence that the strengths of the I-band sodium doublet and the nearby I-band calcium triplet may jointly indicate α-element enrichment. The use of these I-band features requires only moderate-resolution near-infrared spectroscopy to provide valuable information about the potential habitability of exoplanets around M dwarfs, and surface gravity and distance for M dwarfs throughout the Galaxy. This technique has immediate applicability for both target selection and candidate planet–host system characterization for exoplanet missions such as TESS and K2.

  16. Laser beam shape and curvature radius of the laser wavefront passing through ZnO nanostructures

    NASA Astrophysics Data System (ADS)

    Mousavi, S. H.; Haratizadeh, H.

    2012-03-01

    In the present work, we focus on synthesis and optical properties of ZnO nanostructures prepared by the chemical vapour deposition method. The nonlinear optical properties of ZnO nanostructures in ethanol solution were studied by the Z-scan technique using CW He-Ne laser at 632.8 nm. The results show a negative nonlinearity and a large nonlinear refractive index. The magnitude and the sign of nonlinear refractive index, n2, were measured using the single beam Z-scan technique. The effect of morphology on nonlinear optical properties of ZnO nanowires is investigated. The laser beam shape and variation of the curvature radius of the wavefront have been simulated when the Gaussian laser beam passes through ZnO nanowires in ethanol. The effect of concentration is investigated in the nonlinearity. We have reported the curvature radius of the wavefront to the nonlinearity for ZnO nanowires as nonlinear sample. Also we found good agreement between the results of theoretical laser beam shape passing through ZnO nanostructure and the experimental data.

  17. Measurement Of Neutron Radius In Lead By Parity Violating Scattering Flash ADC DAQ

    SciTech Connect

    Ahmed, Zafar

    2012-06-01

    This dissertation reports the experiment PREx, a parity violation experiment which is designed to measure the neutron radius in 208Pb. PREx is performed in hall A of Thomas Jefferson National Accelerator Facility from March 19th to June 21st. Longitudionally polarized electrons at energy 1 GeV scattered at and angle of θlab = 5.8 ° from the Lead target. Beam corrected pairty violaing counting rate asymmetry is (Acorr= 594 ± 50(stat) ± 9(syst))ppb at Q2 = 0.009068GeV 2. This dissertation also presents the details of Flash ADC Data Acquisition(FADC DAQ) system for Moller polarimetry in Hall A of Thomas Jefferson National Accelerator Facility. The Moller polarimeter measures the beam polarization to high precision to meet the specification of the PREx(Lead radius experiment). The FADC DAQ is part of the upgrade of Moller polarimetery to reduce the systematic error for PREx. The hardware setup and the results of the FADC DAQ analysis are presented

  18. Treatment of scaphoid nonunion with vascularised and nonvascularised dorsal bone grafting from the distal radius

    PubMed Central

    Medina, Carlos Eduardo Gonzalez; Mattar, Rames; Ulson, Heitor Jose Rizzardo; de Resende, Marcelo Rosa; Etchebehere, Mauricio

    2009-01-01

    We conducted a prospective randomised study comparing the clinical, functional and radiographic results of 46 patients treated for scaphoid nonunion using a vascularised bone graft from the dorsal and distal aspect of the radius (group I), relative to 40 patients treated by means of a conventional non-vascularised bone graft from the distal radius (group II). Surgical findings included 30 sclerotic, poorly-vascularised scaphoids in group I versus 20 in group II. Bone fusion was achieved in 89.1% of group I and 72.5% of group II patients (p = 0.024). Functional results were good to excellent in 72.0% of the patients in group I and 57.5% in group II. Considering only patients with sclerotic, poorly-vascularised scaphoids, the mean final outcome scores obtained were 7.5 and 6.0 for groups I and group II, respectively. We conclude that vascularised bone grafting yields superior results and is more efficient when there is a sclerotic, poorly-vascularised proximal pole in patients in scaphoid nonunion. PMID:19730861

  19. Linear vs. nonlinear acceleration in plasma turbulence. II. Hall–finite-Larmor-radius magnetohydrodynamics

    SciTech Connect

    Ghosh, Sanjoy; Parashar, Tulasi N.

    2015-04-15

    The local k-space ratio of linear and nonlinear accelerations associated with a variety of initial conditions undergoing steady relaxation is investigated for the Hall–finite-Larmor-radius magnetohydrodynamics (MHD) system in the presence of a mean magnetic field. Building on a related study (Paper I) where it was shown that discrepancies exist between describing the global and local characterizations of the pure MHD system with mean magnetic field, we find regions of the Fourier space that are consistently dominated by linear acceleration and other regions that are consistently dominated by nonlinear acceleration, independent of the overall system's description as linear, weakly nonlinear, or turbulent. In general, dynamics within a certain angular range of the mean magnetic field direction are predominantly linear, while dynamics adjacent the Hall scales along the field-parallel direction and dynamics adjacent the finite Larmor radius scales in the field-perpendicular direction can become strongly nonlinear. The nonlinear influences are particularly significant as the plasma beta increases from unity to higher values.

  20. A Brachioradialis Splitting Approach Sparing the Pronator Quadratus for Volar Plating of the Distal Radius.

    PubMed

    Kashir, Abdalla; O'Donnell, Turlough

    2015-12-01

    Fractures of the distal radius account for up to 15% of all extremity fractures. Volar plating has become more popular, as it allows locking plate technology to be applied. Traditionally, access to the volar radius has been achieved through the approach of Henry using the interval between flexor carpi radialis and the radial artery, involving incising the radial border of the pronator quadratus (PQ). With this approach, PQ repair is difficult, and when attempted is often incomplete or tenuous, as it is a direct muscle-to-muscle repair. Theoretical advantages of repairing the PQ include the provision of plate coverage, a protective gliding layer, a well-vascularized coverage of the fracture fragments, and a protective barrier against deep infection in the case of superficial infection. Techniques have been developed to try and improve on the Henry approach. We have developed a surgical approach to volar plating that utilizes the anatomic relationship between brachioradialis and PQ in a way that allows simple and stable reattachment of the PQ muscle. We have termed the technique the "Brachioradialis splitting" approach. We present it here.

  1. Can carpal malalignment predict early and late instability in nonoperatively managed distal radius fractures?

    PubMed

    Batra, Sameer; Debnath, U; Kanvinde, R

    2008-10-01

    The purpose of this study was to assess the frequency of carpal instability as a concomitant lesion in distal radius fractures and identify other factors including carpal malalignment in an attempt to predict the final radiological outcome more accurately following conservative treatment of distal radius fractures. An observational study from patient records and standardised radiological follow-up examinations as data sources was used. The alignment of each wrist was checked radiographically immediately post-reduction and subsequently at 1- and 6-week follow-up assessments. Serial measurements of radial length, dorsal tilt, radial inclination, scapho-lunate, radio-lunate, radioscaphoid, scapho-capitate angles and effective radiolunate flexion angle were made. Regression analysis showed high correlation among the severity of axial shortening, pre-reduction dorsal angulation and radio-carpal malalignment pattern with early loss of reduction at 1 week. We found the age, severity of axial radial shortening, dorsal angulation, presence of dorsal comminution and radio-carpal malalignment pattern to be significant predictors of adverse radiological outcome at 6 weeks (late instability). Our study highlights the importance of radio-carpal instability pattern on post-reduction radiographs as a predictor of early and late instability.

  2. The Definition and Significance of an Effective Radius for Ice Clouds.

    NASA Astrophysics Data System (ADS)

    McFarquhar, Greg M.; Heymsfield, Andrew J.

    1998-06-01

    Single scattering shortwave properties of ice clouds are frequently derived in terms of the `effective' radius (re) of the ice crystal population. Substantial discrepancies between definitions exist, making interpretation and comparison of various radiative parameterization schemes and satellite retrieval techniques difficult. Each definition of effective radius can be related to more physically based parameters, such as the crystal dimension of median mass. For vertically inhomogeneous clouds, the relative importance of different cloud heights in determining the retrieved re is examined, and a definition of re for vertically inhomogeneous clouds composed of hexagonal columns is proposed. This definition shows reasonable agreement with the re values that would be retrieved using visible and near-infrared channels for some microphysical data acquired in tropical ice clouds near Kwajalein, Marshall Islands, in the mid-1970s. Because only the upper parts of a thick ice cloud are detected by satellite, and because the near-infrared channels demonstrate reduced sensitivity to large crystals, it may not be possible to obtain information about typical particle sizes over the entire depth of thick clouds using current satellite retrievals alone.

  3. A method to provide rapid in situ determination of tip radius in dynamic atomic force microscopy.

    PubMed

    Santos, Sergio; Guang, Li; Souier, Tewfik; Gadelrab, Karim; Chiesa, Matteo; Thomson, Neil H

    2012-04-01

    We provide a method to characterize the tip radius of an atomic force microscopy in situ by monitoring the dynamics of the cantilever in ambient conditions. The key concept is that the value of free amplitude for which transitions from the attractive to repulsive force regimes are observed, strongly depends on the curvature of the tip. In practice, the smaller the value of free amplitude required to observe a transition, the sharper the tip. This general behavior is remarkably independent of the properties of the sample and cantilever characteristics and shows the strong dependence of the transitions on the tip radius. The main advantage of this method is rapid in situ characterization. Rapid in situ characterization enables one to continuously monitor the tip size during experiments. Further, we show how to reproducibly shape the tip from a given initial size to any chosen larger size. This approach combined with the in situ tip size monitoring enables quantitative comparison of materials measurements between samples. These methods are set to allow quantitative data acquisition and make direct data comparison readily available in the community.

  4. Nanoscale contact-radius determination by spectral analysis of polymer roughness images.

    PubMed

    Knoll, Armin W

    2013-11-12

    In spite of the long history of atomic force microscopy (AFM) imaging of soft materials such as polymers, little is known about the detailed effect of a finite tip size and applied force on the imaging performance on such materials. Here we exploit the defined scaling of roughness amplitudes on amorphous polymer films to determine the transfer function imposed by the imaging tip. The finite indentation of the nanometer-scale tip into the comparatively soft polymer surface leads to a finite contact area, which in turn effectively acts as a moving average filter for the surface roughness. In the power spectral density (PSD), this leads to an attenuation of the roughness amplitudes related to the Airy pattern known from light diffraction of a circular aperture. This transfer function is affected by the roughness-induced local modulation of the tip height and contact area, which is studied by performing simulations of the polymer roughness and the imaging process. We find that for typical polymer parameters and sharp tips the contact radius of the tip-sample contact can be recovered from the roughness spectrum. We experimentally verify and demonstrate the method by measuring the nanoscale contact radius as a function of applied load and travel distance on a highly cross-linked model polymer. The data are consistent with the Johnson-Kendall-Roberts (JKR) contact model and verifies its applicability at the nanometer scale. Using the model, quantitative values of the elastic sample parameters can be determined.

  5. Experimental research on radius of curvature measurement of spherical lenses based on laser differential confocal technique

    NASA Astrophysics Data System (ADS)

    Ding, Xiang; Sun, Ruoduan; Li, Fei; Zhao, Weiqian; Liu, Wenli

    2011-11-01

    A new approach based on laser differential confocal technique is potential to achieve high accuracy in radius of curvature (ROC) measurement. It utilizes two digital microscopes with virtual pinholes on the CCD detectors to precisely locate the cat's-eye and the confocal positions, which can enhance the focus-identification resolution. An instrumental system was established and experimental research was carried out to determine how error sources contribute to the uncertainty of ROC measurement, such as optical axis misalignment, dead path of the interferometer, surface figure error of tested lenses and temperature fluctuation, etc. Suggestions were also proposed on how these factors could be avoided or suppressed. The system performance was tested by employing four pairs of template lenses with a serial of ROC values. The relative expanded uncertainty was analyzed and calculated based on theoretical analysis and experimental determination, which was smaller than 2x10-5 (k=2). The results were supported by comparison measurement between the differential confocal radius measurement (DCRM) system and an ultra-high accuracy three-dimensional profilometer, showing good consistency. It demonstrated that the DCRM system was capable of high-accuracy ROC measurement.

  6. Palæomagnetic evidence relevant to a change in the earth's radius

    USGS Publications Warehouse

    Cox, Allan; Doell, Richard R.

    1961-01-01

    INTEREST in the hypothesis that the Earth's radius has increased during geological history has been renewed in recent years because of several sets of independent observations and interpretations. From studies of the deformation of mountain ranges and the distribution of faults and oceans, Carey1 proposes an increase in the Earth's area of 45 per cent since the Palæozoic era. Heezen2 similarly interprets submarine topography as indicating that the oceans may be immense rift valleys formed by a pulling apart of the continents as the Earth expanded. Using a different approach, Egyed3,4 infers a rate of increase of the Earth's radius of 0.4–0.8 mm. per year. This calculation is based on a decrease in the total amount of continental area covered by oceans during the past 400 million years, as determined palæographically. Egyed4 has also pointed out the desirability of using palæomagnetic data to test this hypothesis.

  7. Grout long radius flow testing to support Saltstone disposal Unit 5 design

    SciTech Connect

    Stefanko, D. B.; Langton, C. A.; Serrato, M. G.; Brooks, T. E. II; Huff, T. H.

    2013-02-24

    The Saltstone Facility, located within the Savannah River Site (SRS) near Aiken, South Carolina, consists of two facility segments: The Saltstone Production Facility (SPF) and the Saltstone Disposal Facility (SDF). The SPF receives decontaminated legacy low level sodium salt waste solution that is a byproduct of prior nuclear material processing. The salt solution is mixed with cementitious materials to form a grout slurry known as “Saltstone”. The grout is pumped to the SDF where it is placed in a Saltstone Disposal Unit (SDU) to solidify. SDU 6 is referred to as a “mega vault” and is currently in the design stage. The conceptual design for SDU 6 is a single cell, cylindrical geometry approximately 114.3 meters in diameter by 13.1 meter high and is larger than previous cylindrical SDU designs, 45.7 meters in diameter by 7.01 meters high (30 million gallons versus 2.9 million gallons of capacity). Saltstone slurry will be pumped into the new waste disposal unit through roof openings at a projected flow rate of about 34.1 cubic meters per hour. Nine roof openings are included in the design to discharge material into the SDU with an estimated grout pour radius of 22.9 to 24.4 meters and initial drop height of 13.1 meters. The conceptual design for the new SDU does not include partitions to limit the pour radius of the grout slurry during placement other than introducing material from different pour points. This paper addresses two technical issues associated with the larger diameter of SDU 6; saltstone flow distance in a tank 114.3 meters in diameter and quality of the grout. A long-radius flow test scaled to match the velocity of an advancing grout front was designed to address these technology gaps. The emphasis of the test was to quantify the flow distance and to collect samples to evaluate cured properties including compressive strength, porosity, density, and saturated hydraulic conductivity. Two clean cap surrogate mixes (saltstone premix plus water

  8. Vascularized proximal fibular autograft for treatment of post-traumatic segmental bony defects in the distal radius.

    PubMed

    Shimizu, Takamasa; Yajima, Hiroshi; Kobata, Yasunori; Shigematsu, Koji; Kawamura, Kenji; Takakura, Yoshinori

    2008-11-01

    Vascularized proximal fibular autograft is reported as one of the reconstructive procedures for the wrists following tumor resection in the distal end of the radius. However, it is rarely performed for the treatment of segmental bony defects in the distal radius after trauma. A 19-year-old man who had traumatic bony defects in the distal radius involving the articular surface underwent vascularized proximal fibular grafting for reconstruction of the wrist. After surgery, he regained wrist functions, with 40 degrees of flexion, 45 degrees of extension, 90 degrees of pronation, and 45 degrees of supination. No evidence of instability or degenerative changes was noted in the reconstructed wrist at 3 years after surgery. Vascularized proximal fibular autograft appears a useful procedure both for reconstruction of the wrist in cases with segmental bony defects in the distal radius after trauma, as well as for after tumor resection. PMID:18925543

  9. The channel radius and energy of cloud-to-ground lightning discharge plasma with multiple return strokes

    SciTech Connect

    Wang, Xuejuan; Yuan, Ping; Cen, Jianyong; Liu, Jianguo; Li, Yajun

    2014-03-15

    Using the spectra of a cloud-to-ground (CG) lightning flash with multiple return strokes and combining with the synchronous radiated electrical field information, the linear charge density, the channel radius, the energy per unit length, the thermal energy, and the energy of dissociation and ionization in discharge channel are calculated with the aid of an electrodynamic model of lightning. The conclusion that the initial radius of discharge channel is determined by the duration of the discharge current is confirmed. Moreover, the correlativity of several parameters has been analyzed first. The results indicate that the total intensity of spectra is positive correlated to the channel initial radius. The ionization and thermal energies have a linear relationship, and the dissociation energy is correlated positively to the ionization and thermal energies, the energy per unit length is in direct proportion to the square of initial radius in different strokes of one CG lightning.

  10. Correlation between dorsovolar translation and rotation of the radius on the distal radioulnar joint during supination and pronation of forearm.

    PubMed

    Lee, Sang Ki; Song, Young Dong; Choy, Won Sik

    2015-09-01

    This study aimed to describe the patterns of movements about radius and ulna in individual degrees of forearm rotation. And, we also determined the effect of forearm rotation on translation and rotation of the radius with reference to the ulna, and to measure the relationship between forearm rotation, translation and rotation of the radius. Computed tomography of multiple, individual forearm positions, from 90° pronation to 90° supination, was conducted in 26 healthy volunteers (mean age, 43.9 years) to measure dorsovolar translation and rotation of the radius in the DRUJ in each forearm position. The mean dorsovolar translations were within 1.99 mm at 90° pronation to -2.03 mm at 90° supination. The rotations of the radius were 71.20° at 90° pronation and -46.63° at 90° supination. There were strong correlations between degrees of forearm rotation and dorsovolar translation (r=0.861, p<0.001) and rotation of the radius (r=0.960, p<0.001), suggesting that the DRUJ, carpal joints, and rotatory laxity of the carpal ligament, especially in supination, contribute to forearm supination and pronation. These findings provide an understanding of wrist kinematics, are may be useful in reconstructive wrist surgery to achieve normal range of motion, and are may be helpful for the design of DRUJ reconstruction using prostheses.

  11. Jets from jets: re-clustering as a tool for large radius jet reconstruction and grooming at the LHC

    NASA Astrophysics Data System (ADS)

    Nachman, Benjamin; Nef, Pascal; Schwartzman, Ariel; Swiatlowski, Maximilian; Wanotayaroj, Chaowaroj

    2015-02-01

    Jets with a large radius R ≳ 1 and grooming algorithms are widely used to fully capture the decay products of boosted heavy particles at the Large Hadron Collider (LHC). Unlike most discriminating variables used in such studies, the jet radius is usually not optimized for specific physics scenarios. This is because every jet configuration must be calibrated, insitu, to account for detector response and other experimental effects. One solution to enhance the availability of large- R jet configurations used by the LHC experiments is jet re-clustering. Jet re-clustering introduces an intermediate scale r < R at which jets are calibrated and used as the inputs to reconstruct large radius jets. In this paper we systematically study and propose new jet re-clustering configurations and show that re-clustered large radius jets have essentially the same jet mass performance as large radius groomed jets. Jet re-clustering has the benefit that no additional large-R calibration is necessary, allowing the re-clustered large radius parameter to be optimized in the context of specific precision measurements or searches for new physics.

  12. Implications of the contact radius to line step (CRLS) ratio in AFM for nanotribology measurements.

    PubMed

    Helt, James M; Batteas, James D

    2006-07-01

    Investigating the mechanisms of defect generation and growth at surfaces on the nanometer scale typically requires high-resolution tools such as the atomic force microscope (AFM). To accurately assess the kinetics and activation parameters of defect production over a wide range of loads (F(z)), the AFM data should be properly conditioned. Generally, AFM wear trials are performed over an area defined by the length of the slow (L(sscan)) and fast scan axes. The ratio of L(sscan) to image resolution (res, lines per image) becomes an important experimental parameter in AFM wear trials because it defines the magnitude of the line step (LS = L(sscan)/res), the distance the AFM tip steps along the slow scan axis. Comparing the contact radius (a) to the line step (LS) indicates that the overlap of successive scans will result unless the contact radius-line step ratio (CRLS) is < or =(1)/(2). If this relationship is not considered, then the scan history (e.g., contact frequency) associated with a single scan is not equivalent at different loads owing to the scaling of contact radius with load (a proportional variant F(z)(1/3)). Here, we present a model in conjunction with empirical wear tests on muscovite mica to evaluate the effects of scan overlap on surface wear. Using the Hertz contact mechanics definition of a, the CRLS model shows that scan overlap pervades AFM wear trials even under low loads. Such findings indicate that simply counting the number of scans (N(scans)) in an experiment underestimates the full history conveyed to the surface by the tip and translates into an error in the actual extent to which a region on the surface is contacted. Utilizing the CRLS method described here provides an approach to account for image scan history accurately and to predict the extent of surface wear. This general model also has implications for any AFM measurement where one wishes to correlate scan-dependent history to image properties as well as feature resolution in scanned

  13. Primary Wrist Hemiarthroplasty for Irreparable Distal Radius Fracture in the Independent Elderly

    PubMed Central

    Herzberg, Guillaume; Burnier, Marion; Marc, Antoine; Izem, Yadar

    2015-01-01

    Background Volar plating for acute distal radius fractures (DRF) in the elderly has been recommended. Some studies have suggested that open reduction with internal fixation (ORIF) in this situation results in frequent complications. Our purposes were to provide a definition of irreparable DRF in independent elderly patients and to review the results of a preliminary retrospective series of wrist hemiarthroplasty (WHA) in this patient population. Materials Between 2011 and 2014, 11 consecutive independent elderly patients (12 wrists) with irreparable intra-articular DRF were treated with primary WHA at the acute stage. A resection of the ulnar head was associated in nine wrists. A total of 11 wrists with more than 2 years of follow-up form the basis of this paper. Description of Technique The approach was dorsal longitudinal. An osteotome longitudinally entered the dorsal aspect of the fracture medial to the Lister tubercle. Two thick osteoperiosteal flaps were elevated radially and ulnarly in a fashion similar to opening a book. The distal radius articular surface was excised. The implant was pressed into the radial canal with attention to restoring distal radius length. The two osteoperiosteal flaps were brought back together and sutured so as to close, again like a book, the osseous and soft tissues around the implant. Results At mean follow-up of 30 months, average visual analog scale (VAS) pain was 1/10. Mean QuickDASH (Disabilities of the Arm, Shoulder and Hand) score was 32, and mean Patient-Rated Wrist Evaluation (PRWE) score was 24. Mean forearm rotation arc was 151°. Mean active flexion-extension arc was 60°. Mean active extension was 34°. Mean grip strength was 14 kg (64% of contralateral wrist). Mean Lyon wrist score was 73%. Bone healing around the implants was satisfactory in all but one case. Conclusions Out data suggest that treatment of irreparable DRF in the independent elderly patient with a bone-preserving WHA may be a viable

  14. Tibia and radius bone geometry and volumetric density in obese compared to non-obese adolescents☆

    PubMed Central

    Leonard, Mary B.; Zemel, Babette S.; Wrotniak, Brian H.; Klieger, Sarah B.; Shults, Justine; Stallings, Virginia A.; Stettler, Nicolas

    2015-01-01

    Childhood obesity is associated with biologic and behavioral characteristics that may impact bone mineral density (BMD) and structure. The objective was to determine the association between obesity and bone outcomes, independent of sexual and skeletal maturity, muscle area and strength, physical activity, calcium intake, bio-markers of inflammation, and vitamin D status. Tibia and radius peripheral quantitative CT scans were obtained in 91 obese (BMI > 97th percentile) and 51 non-obese adolescents (BMI > 5th and <85th percentiles). Results were converted to sex- and race-specific Z-scores relative to age. Cortical structure, muscle area and muscle strength (by dynamometry) Z-scores were further adjusted for bone length. Obese participants had greater height Z-scores (p < 0.001), and advanced skeletal maturity (p < 0.0001), compared with non-obese participants. Tibia cortical section modulus and calf muscle area Z-scores were greater in obese participants (1.07 and 1.63, respectively, both p < 0.0001). Tibia and radius trabecular and cortical volumetric BMD did not differ significantly between groups. Calf muscle area and strength Z-scores, advanced skeletal maturity, and physical activity (by accelerometry) were positively associated with tibia cortical section modulus Z-scores (all p < 0.01). Adjustment for muscle area Z-score attenuated differences in tibia section modulus Z-scores between obese and non-obese participants from 1.07 to 0.28. After multivariate adjustment for greater calf muscle area and strength Z-scores, advanced maturity, and less moderate to vigorous physical activity, tibia section modulus Z-scores were 0.32 (95% CI −0.18, 0.43, p = 0.06) greater in obese, vs. non-obese participants. Radius cortical section modulus Z-scores were 0.45 greater (p = 0.08) in obese vs. non-obese participants; this difference was attenuated to 0.14 with adjustment for advanced maturity. These findings suggest that greater tibia cortical section modulus in obese

  15. Implications of the contact radius to line step (CRLS) ratio in AFM for nanotribology measurements.

    PubMed

    Helt, James M; Batteas, James D

    2006-07-01

    Investigating the mechanisms of defect generation and growth at surfaces on the nanometer scale typically requires high-resolution tools such as the atomic force microscope (AFM). To accurately assess the kinetics and activation parameters of defect production over a wide range of loads (F(z)), the AFM data should be properly conditioned. Generally, AFM wear trials are performed over an area defined by the length of the slow (L(sscan)) and fast scan axes. The ratio of L(sscan) to image resolution (res, lines per image) becomes an important experimental parameter in AFM wear trials because it defines the magnitude of the line step (LS = L(sscan)/res), the distance the AFM tip steps along the slow scan axis. Comparing the contact radius (a) to the line step (LS) indicates that the overlap of successive scans will result unless the contact radius-line step ratio (CRLS) is < or =(1)/(2). If this relationship is not considered, then the scan history (e.g., contact frequency) associated with a single scan is not equivalent at different loads owing to the scaling of contact radius with load (a proportional variant F(z)(1/3)). Here, we present a model in conjunction with empirical wear tests on muscovite mica to evaluate the effects of scan overlap on surface wear. Using the Hertz contact mechanics definition of a, the CRLS model shows that scan overlap pervades AFM wear trials even under low loads. Such findings indicate that simply counting the number of scans (N(scans)) in an experiment underestimates the full history conveyed to the surface by the tip and translates into an error in the actual extent to which a region on the surface is contacted. Utilizing the CRLS method described here provides an approach to account for image scan history accurately and to predict the extent of surface wear. This general model also has implications for any AFM measurement where one wishes to correlate scan-dependent history to image properties as well as feature resolution in scanned

  16. Assessment of the healing process in distal radius fractures by high resolution peripheral quantitative computed tomography.

    PubMed

    de Jong, Joost J A; Willems, Paul C; Arts, Jacobus J; Bours, Sandrine G P; Brink, Peter R G; van Geel, Tineke A C M; Poeze, Martijn; Geusens, Piet P; van Rietbergen, Bert; van den Bergh, Joop P W

    2014-07-01

    In clinical practice, fracture healing is evaluated by clinical judgment in combination with conventional radiography. Due to limited resolution, radiographs don't provide detailed information regarding the bone micro-architecture and bone strength. Recently, assessment of in vivo bone density, architectural and mechanical properties at the microscale became possible using high resolution peripheral quantitative computed tomography (HR-pQCT) in combination with micro finite element analysis (μFEA). So far, such techniques have been used mainly to study intact bone. The aim of this study was to explore whether these techniques can also be used to assess changes in bone density, micro-architecture and bone stiffness during fracture healing. Therefore, the fracture region in eighteen women, aged 50 years or older with a stable distal radius fracture, was scanned using HR-pQCT at 1-2 (baseline), 3-4, 6-8 and 12weeks post-fracture. At 1-2 and 12 weeks post-fracture the distal radius at the contra-lateral side was also scanned as control. Standard bone density, micro-architectural and geometric parameters were calculated and bone stiffness in compression, torsion and bending was assessed using μFEA. A linear mixed effect model with time post-fracture as fixed effect was used to detect significant (p-value ≤0.05) changes from baseline. Wrist pain and function were scored using the patient-rated wrist evaluation (PRWE) questionnaire. Correlations between the bone parameters and the PRWE score were calculated by Spearman's correlation coefficient. At the fracture site, total and trabecular bone density increased by 11% and 20%, respectively, at 6-8 weeks, whereas cortical density was decreased by 4%. Trabecular thickness increased by 23-31% at 6-8 and 12 weeks and the intertrabecular area became blurred, indicating intertrabecular bone formation. Compared to baseline, calculated bone stiffness in compression, torsion and bending was increased by 31% after 12 weeks. A

  17. First experimentally determined thermodynamic values of francium: hydration energy, energy of partitioning, and thermodynamic radius.

    PubMed

    Delmau, Lætitia H; Moine, Jérôme; Mirzadeh, Saed; Moyer, Bruce A

    2013-08-01

    The Gibbs energy of partitioning of Fr(+) ion between water and nitrobenzene has been determined to be 14.5 ± 0.6 kJ/mol at 25 °C, the first ever Gibbs energy of partitioning for francium in particular and the first ever solution thermodynamic quantity for francium in general. This value enabled the ionic radius and standard Gibbs energy of hydration for Fr(+) to be estimated as 173 pm and -251 kJ/mol, respectively, the former value being significantly smaller than previously thought. A new experimental method was established using a cesium dicarbollide as a cation-exchange agent, overcoming problems inherent to the trace-level concentrations of francium. The methodology opens the door to the study of the partitioning behavior of francium to other water-immiscible solvents and the determination of complexation constants for francium binding by receptor molecules. PMID:23848436

  18. How do sharp transmission boundaries change the effective radius of a transiting exoplanet?

    NASA Astrophysics Data System (ADS)

    Betremieux, Yan; Swain, Mark R.

    2016-10-01

    Most radiative transfer codes for exoplanet transmission spectroscopy either use or are validated against the formalism of Lecavelier des Etangs et al. (2008). Although extremely useful to understand what shapes transmission spectra, this formalism does not consider the effects of sharp boundaries below which an exoplanet's limb transmission suddenly decreases. However, with recent advances on the effects of refraction in transmission spectroscopy (Bétrémieux & Kaltenegger 2014, Bétrémieux 2016), it turns out that all exoplanets possess one such boundary in the form of either a surface, optically-thick clouds, or in the form of a refractive boundary. We have deriveda first-order analytical expression for an exoplanet's effective radius, which can be used to further validate or improve radiative transfer codes, which accounts for the presence of these boundaries, and discuss their effects on exoplanetary transmission spectra.

  19. A Silicon detector system on carbon fiber support at small radius

    SciTech Connect

    Marvin E. Johnson

    2004-04-28

    The design of a silicon detector for a p{bar p} collider experiment will be described. The detector uses a carbon fiber support structure with sensors positioned at small radius with respect to the beam. A brief overview of the mechanical design is given. The emphasis is on the electrical characteristics of the detector. General principles involved in grounding systems with carbon fiber structures will be covered. The electrical characteristics of the carbon fiber support structure will be presented. Test results imply that carbon fiber must be regarded as a conductor for the frequency region of interest of 10 to 100 MHz. No distinction is found between carbon fiber and copper. Performance results on noise due to pick-up through the low mass fine pitch cables carrying the analogue signals and floating metal is discussed.

  20. [Secondary dislocations in fractures of the distal end of the radius].

    PubMed

    Zdun, H; Kanchanlall, W

    1990-01-01

    In the group of 31 patients treated by immobilization of the forearm we observed 71% of secondary dislocations and in group of 46 with the full-arm plaster 65% of secondary dislocation occurred. In the group of 20 patients with the full-arm plaster and the X-ray done between the 7th and 10th day after reduction to correct possible dislocation, followed always by the new, similar plaster cast, we observed 40% of secondary dislocations. Whenever the full-arm plaster was used Sudeck syndrome was observed very rarely. No direct relationship between kind of plaster used and the degree of shortening of the radius length after healing of the fracture was found. Comminuted fractures and osteoporosis are in favour for secondary dislocations. PMID:1369865

  1. [Technique and results of modified percutaneous bore wire osteosynthesis of the distal radius].

    PubMed

    Habernek, H; Schmid, L

    1992-07-01

    A modified technique for percutaneous K-wire pinning of distal radius fractures is presented. With this method, three to four K-wires are introduced from the radial styloid process towards and through the dorsal, volar and ulnar proximal cortical wall, respectively. After the fracture fragments have been demonstrated to be stable, the wires are cut, bent over and fixed. Then a dorsal plaster splint is applied, which should be worn for 4-6 weeks, depending on whether or not there is a dorsal comminution zone. Fifty-five patients have been operated on by this method. At follow-up 6 months after the operation, no secondary dislocation, wire migration, infection, Sudeck syndrome or functional disturbance was seen. The advantage of this method is emphasized as compared with the usual, previously published method. PMID:1502573

  2. Mass, radius and composition of the outer crust of nonaccreting cold neutron stars

    NASA Astrophysics Data System (ADS)

    Hempel, Matthias; Schaffner-Bielich, Jürgen

    2008-01-01

    The properties and composition of the outer crust of nonaccreting cold neutron stars are studied by applying the model of Baym, Pethick and Sutherland, which was extended by including higher order corrections of the atomic binding, screening, exchange and zero-point energy. The most recent experimental nuclear data from the atomic mass table of Audi, Wapstra and Thibault from 2003 are used. Extrapolation to the drip line is utilized by various state-of-the-art theoretical nuclear models (finite range droplet, relativistic nuclear field and non-relativistic Skyrme Hartree Fock parameterizations). The different nuclear models are compared with respect to the mass and radius of the outer crust for different neutron star configurations and the nuclear compositions of the outer crust.

  3. Constraining the mass-radius relation of neutron stars through superbursts

    NASA Astrophysics Data System (ADS)

    In't Zand, Jean

    2011-10-01

    Superbursts are thermonuclear X-ray flashes on neutron stars that last up to 14~hr. We propose to carry out 2 quick 25 ks XMM-Newton triggered observations on superbursts from any of 30 (candidate) superbursters that persistently radiate at 30% of Eddington or slower, with the purpose to carry out X-ray spectroscopy of the neutron star surface and constrain the mass-radius relation and equation of state of neutron stars. We will make use of superburst alerts from INTEGRAL/IBIS, Swift/BAT and ISS-MAXI. The potential of this program is at least as good as that of the program on EXO 0748-676, but at much reduced exposure requirements (50 ks in total).

  4. Constraining the mass-radius relation of neutron stars through superbursts

    NASA Astrophysics Data System (ADS)

    in't Zand, Jean

    2010-10-01

    Superbursts are thermonuclear X-ray flashes on neutron stars that last up to 14 hr. We propose to carry out 2 quick 25 ks XMM-Newton triggered observations on superbursts from any of 23 (candidate) superbursters that persistently radiate at 30% of Eddington or slower, to carry out high-resolution X-ray spectroscopy of the neutron star surface and constrain the mass-radius relation and equation of state of neutron stars. We will make use of superburst alerts from INTEGRAL/IBIS and Swift/BAT. The potential of this program is at least as good as that of the program on EXO 0748-676, but at much reduced exposure requirements (50 ks in total).

  5. Orientation illusions and heart-rate changes during short-radius centrifugation

    NASA Technical Reports Server (NTRS)

    Hecht, H.; Kavelaars, J.; Cheung, C. C.; Young, L. R.

    2001-01-01

    Intermittent short-radius centrifugation is a promising countermeasure against the adverse effects of prolonged weightlessness. To assess the feasibility of this countermeasure, we need to understand the disturbing sensory effects that accompany some movements carried out during rotation. We tested 20 subjects who executed yaw and pitch head movements while rotating at constant angular velocity. They were supine with their main body axis perpendicular to earth gravity. The head was placed at the centrifuge's axis of rotation. Head movements produced a transient elevation of heart-rate. All observers reported head-contingent sensations of body tilt although their bodies remained supine. Mostly, the subjective sensations conform to a model based on semicircular canal responses to angular acceleration. However, some surprising deviations from the model were found. Also, large inter-individual differences in direction, magnitude, and quality of the illusory body tilt were observed. The results have implications for subject screening and prediction of subjective tolerance for centrifugation.

  6. Response of Ambulatory Human Subjects to Artificial Gravity (Short Radius Centrifugation)

    NASA Technical Reports Server (NTRS)

    Paloski, William H.; Arya, Maneesh; Newby, Nathaniel; Tucker, Jon-Michael; Jarchow, Thomas; Young, Laurence

    2006-01-01

    Prolonged exposure to microgravity results in significant adaptive changes, including cardiovascular deconditioning, muscle atrophy, bone loss, and sensorimotor reorganization, that place individuals at risk for performing physical activities after return to a gravitational environment. Planned missions to Mars include unprecedented hypogravity exposures that would likely result in unacceptable risks to crews. Artificial gravity (AG) paradigms may offer multisystem protection from the untoward effects of adaptation to the microgravity of space or the hypogravity of planetary surfaces. While the most effective AG designs would employ a rotating spacecraft, perceived issues may preclude their use. The questions of whether and how intermittent AG produced by a short radius centrifuge (SRC) could be employed have therefore sprung to the forefront of operational research. In preparing for a series of intermittent AG trials in subjects deconditioned by bed rest, we have examined the responses of several healthy, ambulatory subjects to SRC exposures.

  7. Numerical Investigation Of Nonlinear Waves Connected To Blood Flow In An Elastic Tube With Variable Radius

    NASA Astrophysics Data System (ADS)

    Dimitrova, Zlatinka I.

    2015-12-01

    We investigate flow of incompressible fluid in a cylindrical tube with elastic walls. The radius of the tube may change along its length. The discussed problem is connected to the fluid-structure interaction in large human arteries and especially to nonlinear effects. The long-wave approximation is applied to solve model equations. The obtained model Korteweg-deVries equation possessing a variable coefficient is reduced to a nonlinear dynamical system of three first order differential equations. The low probability of a solitary wave arising is shown. Periodic wave solutions of the model system of equations are studied and it is shown that the waves, that are consequence of the irregular heart pulsations may be modelled by a sequence of parts of such periodic wave solutions.

  8. Automated Classification of Epiphyses in the Distal Radius and Ulna using a Support Vector Machine.

    PubMed

    Wang, Ya-hui; Liu, Tai-ang; Wei, Hua; Wan, Lei; Ying, Chong-liang; Zhu, Guang-you

    2016-03-01

    The aim of this study was to automatically classify epiphyses in the distal radius and ulna using a support vector machine (SVM) and to examine the accuracy of the epiphyseal growth grades generated by the support vector machine. X-ray images of distal radii and ulnae were collected from 140 Chinese teenagers aged between 11.0 and 19.0 years. Epiphyseal growth of the two elements was classified into five grades. Features of each element were extracted using a histogram of oriented gradient (HOG), and models were established using support vector classification (SVC). The prediction results and the validity of the models were evaluated with a cross-validation test and independent test for accuracy (PA ). Our findings suggest that this new technique for epiphyseal classification was successful and that an automated technique using an SVM is reliable and feasible, with a relative high accuracy for the models. PMID:27404614

  9. Salter-Harris type-IV displaced distal radius fracture in a 5-year-old.

    PubMed

    Huntley, Samuel R; Summers, Spencer H; Stricker, Stephen J

    2016-03-01

    Displaced Salter-Harris type-IV fractures are rare in young children and can result in articular incongruity or premature physeal arrest. We describe a 5-year-old boy who sustained a displaced left distal radial Salter-Harris type-IV fracture. The patient had normal wrist function and physeal growth at the 3-year postoperative follow-up. Our patient is by far the youngest reported child with a displaced Salter-Harris type-IV fracture of the distal radius. Prompt anatomic reduction and fixation of a displaced distal radial Salter-Harris type-IV fracture can result in excellent short-term wrist motion with maintenance of physeal function.

  10. Intraoperative C-arm CT imaging in angular stable plate osteosynthesis of distal radius fractures.

    PubMed

    Mehling, I; Rittstieg, P; Mehling, A P; Küchle, R; Müller, L P; Rommens, P M

    2013-09-01

    The purpose of this study was to analyze the practicability and benefit of intraoperative C-arm computed tomography (CT) imaging in volar plate osteosynthesis of unstable distal radius fractures. During a 1 year period, intraoperative three dimensional (3D) imaging with the ARCADIS Orbic 3D was performed in addition to standard fluoroscopy in 51 cases. The volar angular stable plate oesteosyntheses were analyzed intraoperatively and, if necessary, improved immediately. The duration of the scan and radiation exposure dose were measured. On average, performance of the scan and analysis of the CT dataset took 6.7 minutes. In 31.3% of the surgeries a misplacement of screws was detected and correction was done immediately. C-arm CT imaging can easily be integrated in the normal course of surgery. As a complement to the standard 2D-fluoroscopy, the C-arm CT is a useful tool to evaluate the quality of osteosynthesis.

  11. Aerothermal Performance Constraints for Hypervelocity Small Radius Unswept Leading Edges and Nosetips

    NASA Technical Reports Server (NTRS)

    Kolodziej, Paul

    1997-01-01

    Small radius leading edges and nosetips were utilized to minimize wave drag in early hypervelocity vehicle concepts until further analysis demonstrated that extreme aerothermodynamic heating would cause severe ablation or blunting of the available thermal protection system materials. Recent studies indicate that ultrahigh temperature ceramic (UHTC) materials are shape stable at temperatures approaching 3033 K and will be available for use as sharp UHTC leading edge components in the near future. Aerothermal performance constraints for sharp components made from these materials are presented in this work to demonstrate the effects of convective blocking, surface catalycity, surface emissivity, and rarefied flow effects on steady state operation at altitudes from sea level to 90 km. These components are capable of steady state operation at velocities up to 7.9 km/s at attitudes near 90 km.

  12. Measurement of the Earth's radius based on historical evidence of its curvature

    NASA Astrophysics Data System (ADS)

    Roura, Pere; Calbó, Josep

    2005-09-01

    Probably the most direct observation of the Earth’s curvature is how objects appear from over the horizon when we approach them and disappear as we get further away from them. Similarly, the portion of a high object (a building or a mountain) that is visible depends on the height of the site where the observation is made. Based upon these very obvious facts, a simple method to estimate the Earth's radius R has been applied. The method does not need either sophisticated instrumentation or complex mathematics. In our application of the method presented here, the result is R = 6600 +/- 600 km in the best case. A discussion is presented about the possible use of this method in ancient times. Surprisingly enough, we have not found any reference to the use of this method despite its being simpler than, for example, the classical approach of Eratosthenes.

  13. Acute plastic bowing of the radius with a distal radioulnar joint injury: a case report.

    PubMed

    Uehara, Masashi; Yamazaki, Hiroshi; Kato, Hiroyuki

    2010-01-01

    Acute plastic bowing is an incomplete fracture with a deformation that shows no obvious macroscopic fracture line or cortical discontinuity. Although cases of acute plastic bowing of the ulna with a dislocation of the radial head have been previously reported, we present here a rare case of acute plastic bowing of the radius with a distal radioulnar joint injury in a 16-year-old boy. Internal fixation of the detached fragment to the ulnar styloid and repair of the triangular fibrocartilagenous complex resulted in the disappearance of wrist pain. In cases of distal radioulnar joint injuries in children or adolescents, radiographs of the entire forearm should be taken to evaluate the existence of radial bowing. PMID:21089197

  14. Radius constraints from high-speed photometry of 20 low-mass white dwarf binaries

    SciTech Connect

    Hermes, J. J.; Brown, Warren R.; Kilic, Mukremin; Gianninas, A.; Chote, Paul; Sullivan, D. J.; Winget, D. E.; Bell, Keaton J.; Falcon, R. E.; Winget, K. I.; Harrold, Samuel T.; Montgomery, M. H.; Mason, Paul A.

    2014-09-01

    We carry out high-speed photometry on 20 of the shortest-period, detached white dwarf binaries known and discover systems with eclipses, ellipsoidal variations (due to tidal deformations of the visible white dwarf), and Doppler beaming. All of the binaries contain low-mass white dwarfs with orbital periods of less than four hr. Our observations identify the first eight tidally distorted white dwarfs, four of which are reported for the first time here. We use these observations to place empirical constraints on the mass-radius relationship for extremely low-mass (≤0.30 M {sub ☉}) white dwarfs. We also detect Doppler beaming in several of these binaries, which confirms their high-amplitude radial-velocity variability. All of these systems are strong sources of gravitational radiation, and long-term monitoring of those that display ellipsoidal variations can be used to detect spin-up of the tidal bulge due to orbital decay.

  15. Ion finite Larmor radius effects on the interchange instability in an open system

    SciTech Connect

    Katanuma, I.; Sato, S.; Okuyama, Y.; Kato, S.; Kubota, R.

    2013-11-15

    A particle simulation of an interchange instability was performed by taking into account the ion finite Larmor radius (FLR) effects. It is found that the interchange instability with large FLR grows in two phases, that is, linearly growing phase and the nonlinear phase subsequent to the linear phase, where the instability grows exponentially in both phases. The linear growth rates observed in the simulation agree well with the theoretical calculation. The effects of FLR are usually taken in the fluid simulation through the gyroviscosity, the effects of which are verified in the particle simulation with large FLR regime. The gyroviscous cancellation phenomenon observed in the particle simulation causes the drifts in the direction of ion diamagnetic drifts.

  16. Interchange and Flow Velocity Shear Instabilities in the Presence of Finite Larmor Radius Effects

    NASA Astrophysics Data System (ADS)

    Sotnikov, V.; Kim, T.; Mishin, E.; Genoni, T.; Rose, D.; Mehlhorn, T.

    2014-09-01

    Ionospheric irregularities cause scintillations of electromagnetic signals that can severely affect navigation and transionospheric communication, in particular during Equatorial Plasma Bubbles (EPBs) events. However, the existing ionospheric models do not describe density irregularities with typical scales of several ion Larmor radii that affect UHF and L bands. These irregularities can be produced in the process of nonlinear evolution of interchange or flow velocity shear instabilities. The model of nonlinear development of these instabilities based on two-fluid hydrodynamic description with inclusion of finite Larmor radius effects will be presented. The derived nonlinear equations will be numerically solved by using the code Flute, which was originally developed for High Energy Density applications and modified to describe interchange and flow velocity shear instabilities in the ionosphere. The high-resolution simulations will be driven by the ambient conditions corresponding to the AFRL C/NOFS satellite low-resolution data during EPBs.

  17. Retrospective comparison of percutaneous fixation and volar internal fixation of distal radius fractures.

    PubMed

    Lozano-Calderón, Santiago A; Doornberg, Job N; Ring, David

    2008-06-01

    A change in the practice of a single surgeon provided an opportunity for retrospective comparison of comparable cohorts treated with percutaneous fixation (17 patients) or a volar plate and screws (23 patients) an average of 30 months after surgery. The final evaluation was performed according to the Gartland and Werley and Mayo rating systems and the DASH questionnaire. There were no significant differences on the average scores for the percutaneous and volar plating groups, respectively: Gartland and Werley, 4 vs 5; Mayo, 82 vs 83; and DASH score 13 for both cohorts. Motion, grip, and radiographical parameters were likewise comparable. Volar internal plate and screw fixation can achieve results comparable to percutaneous fixation techniques in the treatment of fractures of the distal radius.

  18. A possible correlation between planetary radius and orbital period for small planets

    NASA Astrophysics Data System (ADS)

    Helled, Ravit; Lozovsky, Michael; Zucker, Shay

    2016-01-01

    We suggest the existence of a correlation between the planetary radius and orbital period for planets with radii smaller than 4 R⊕. Using the Kepler data, we find a correlation coefficient of 0.5120, and suggest that the correlation is not caused solely by survey incompleteness. While the correlation coefficient could change depending on the statistical analysis, the statistical significance of the correlation is robust. Further analysis shows that the correlation originates from two contributing factors. One seems to be a power-law dependence between the two quantities for intermediate periods (3-100 d), and the other is a dearth of planets with radii larger than 2 R⊕ in short periods. This correlation may provide important constraints for small-planet formation theories and for understanding the dynamical evolution of planetary systems.

  19. TRENDS IN DWARF EARLY-TYPE KINEMATICS WITH CLUSTER-CENTRIC RADIUS DRIVEN BY TIDAL STIRRING

    SciTech Connect

    Benson, A. J.; Toloba, E.; Simon, J. D.; Mayer, L.; Guhathakurta, P.

    2015-02-01

    We model the dynamics of dwarf early-type galaxies in the Virgo cluster when subject to a variety of environmental processes. We focus on how these processes imprint trends in the dynamical state (rotational versus pressure support as measured by the λ{sub Re/2}{sup ∗} statistic) with projected distance from the cluster center, and compare these results to observational estimates. We find a large scatter in the gradient of λ{sub Re/2}{sup ∗} with projected radius. A statistical analysis shows that models with no environmental effects produce gradients as steep as those observed in none of the 100 cluster realizations we consider, while in a model incorporating tidal stirring by the cluster potential 34% of realizations produce gradients as steep as that observed. Our results suggest that tidal stirring may be the cause of the observed radial dependence of dwarf early-type dynamics in galaxy clusters.

  20. Multiasperity contact adhesion model for universal asperity height and radius of curvature distributions.

    PubMed

    Prokopovich, Polina; Perni, Stefano

    2010-11-16

    A new approach to the multiasperities contact interaction between two surfaces is presented. Each asperity is individually considered with its own different height and radius of curvature. Different materials, such as polyvinylchlorine (PVC) and stainless steel, are used as model systems. For each of the model materials, a set of asperities was generated using Monte Carlo method. Both asperity heights and radii were based on their statistical distributions experimentally obtained. Contact forces were determined for each asperity at a given distance between the two surfaces, while the deformation of each asperity was calculated according to the Johnson-Kendall-Roberts (JKR) or the Derjaguin-Muller-Toporov (DMT) model (depending on the material). The contribution of each asperity to the overall surface was summed, and the overall contact force was determined. The developed method was validated against contact force measurements obtained with atomic force microscopy (AFM).

  1. The Hα surface brightness — radius plane as a diagnostic tool for photoionized nebulae

    NASA Astrophysics Data System (ADS)

    Frew, David J.; Bojičić, Ivan S.; Parker, Quentin A.

    2016-07-01

    The Hα surface brightness - radius (SHα-r) relation is a robust distance indicator for planetary nebulae (PNe), further enhanced by different populations of PNe having distinct loci in SHα-r space. Other types of photoionized nebulae also plot in quite distinct regions in the SHa-r plane, allowing its use as a diagnostic tool. In particular, the nova shells and massive star ejecta (MSE) plot on relatively tight loci illustrating their evolutionary sequences. For the MSE, there is potential to develop a distance indicator for these objects, based on their trend in SHα-r space. As high-resolution, narrowband surveys of the nearest galaxies become more commonplace, the SHα-r plane is a potentially useful diagnostic tool to help identify the various ionized nebulae in these systems.

  2. Realization of sub-micron radius of curvature measurement in vertical interferometer workstation

    NASA Astrophysics Data System (ADS)

    Miao, Erlong; Wang, Rudong; Zhang, Wei; Peng, Shijun

    2014-09-01

    Radius of curvature (ROC) is one of the key parameters for optical elements and it is especially important for high quality optical system, in which the computer-aided integration is wildly used. ROC is one of the main input parameters and its measurement accuracy is a premise for high quality integration. In this paper, sub-micron ROC measurements are realized in a vertical interference workstation based on Fizeau interferometer. The error sources and uncertainty of the system are analyzed. Experiment results based on samples with difference ROC are presented and in accordance with the analysis. At last, a ROC comparing tests between the system and a three-coordinates measuring machine (CMM) are performed on a SiC ball to certify the workstation's measurement uncertainty.

  3. REVERBERATION AND PHOTOIONIZATION ESTIMATES OF THE BROAD-LINE REGION RADIUS IN LOW-z QUASARS

    SciTech Connect

    Negrete, C. Alenka; Dultzin, Deborah; Marziani, Paola; Sulentic, Jack W. E-mail: deborah@astro.unam.mx E-mail: sulentic@iaa.es

    2013-07-01

    Black hole mass estimation in quasars, especially at high redshift, involves the use of single-epoch spectra with signal-to-noise ratio and resolution that permit accurate measurement of the width of a broad line assumed to be a reliable virial estimator. Coupled with an estimate of the radius of the broad-line region (BLR) this yields the black hole mass M{sub BH}. The radius of the BLR may be inferred from an extrapolation of the correlation between source luminosity and reverberation-derived r{sub BLR} measures (the so-called Kaspi relation involving about 60 low-z sources). We are exploring a different method for estimating r{sub BLR} directly from inferred physical conditions in the BLR of each source. We report here on a comparison of r{sub BLR} estimates that come from our method and from reverberation mapping. Our ''photoionization'' method employs diagnostic line intensity ratios in the rest-frame range 1400-2000 A (Al III {lambda}1860/Si III] {lambda}1892, C IV {lambda}1549/Al III {lambda}1860) that enable derivation of the product of density and ionization parameter with the BLR distance derived from the definition of the ionization parameter. We find good agreement between our estimates of the density, ionization parameter, and r{sub BLR} and those from reverberation mapping. We suggest empirical corrections to improve the agreement between individual photoionization-derived r{sub BLR} values and those obtained from reverberation mapping. The results in this paper can be exploited to estimate M{sub BH} for large samples of high-z quasars using an appropriate virial broadening estimator. We show that the width of the UV intermediate emission lines are consistent with the width of H{beta}, thereby providing a reliable virial broadening estimator that can be measured in large samples of high-z quasars.

  4. Energy harvesting efficiency optimization via varying the radius of curvature of a piezoelectric THUNDER

    NASA Astrophysics Data System (ADS)

    Wang, Fengxia; Wang, Zengmei; Soroush, Mahmoudiandehkordi; Abedini, Amin

    2016-09-01

    In this work the energy harvesting performance of a piezoelectric curved energy generator (THin layer UNimorph DrivER (THUNDER)) is studied via experimental and analytical methods. The analytical model of the THUNDER is created based on the linear mechanical electrical constitutive law of the piezoelectric material, the linear elastic constitutive law of the substrate, and the Euler–Bernoulli beam theory. With these linear modal functions, the Rayleigh-Ritz approach was used to obtain the reduced mechanical–electrical coupled modulation equations. The analytical model is verified by the experimental results. Both the experimental and analytical results of the THUNDER’s AC power output, DC power output with Rectifier Bridge and a capacitor, as well as the power output with a microcontroller energy harvesting circuit are reported. Based on the theoretical model, the analytical solution of the DC power is derived in terms of the vibration amplitude, frequency, and the electrical load. To harvest energy from low-frequency vibration source by a piezoelectric generator requires the piezoelectric device possessing low resonance frequency and good flexibility. The THUNDER developed by Langley Research Center exhibits high power when it is used as an energy generator and large displacement when it is used as an actuator. Compared to the less flexible PZT, although THUNDER is more difficult to model, THUNDER has better vibration absorption capacity and higher energy recovery efficiency. The effect of the THUNDER’s radius of curvature on energy harvesting efficiency is mainly investigated. We set the THUNDER’s radius of curvature as a dynamic tuning parameter which can tune the piezoelectric generators’ frequency with the source excitation frequency.

  5. Energy harvesting efficiency optimization via varying the radius of curvature of a piezoelectric THUNDER

    NASA Astrophysics Data System (ADS)

    Wang, Fengxia; Wang, Zengmei; Soroush, Mahmoudiandehkordi; Abedini, Amin

    2016-09-01

    In this work the energy harvesting performance of a piezoelectric curved energy generator (THin layer UNimorph DrivER (THUNDER)) is studied via experimental and analytical methods. The analytical model of the THUNDER is created based on the linear mechanical electrical constitutive law of the piezoelectric material, the linear elastic constitutive law of the substrate, and the Euler-Bernoulli beam theory. With these linear modal functions, the Rayleigh-Ritz approach was used to obtain the reduced mechanical-electrical coupled modulation equations. The analytical model is verified by the experimental results. Both the experimental and analytical results of the THUNDER’s AC power output, DC power output with Rectifier Bridge and a capacitor, as well as the power output with a microcontroller energy harvesting circuit are reported. Based on the theoretical model, the analytical solution of the DC power is derived in terms of the vibration amplitude, frequency, and the electrical load. To harvest energy from low-frequency vibration source by a piezoelectric generator requires the piezoelectric device possessing low resonance frequency and good flexibility. The THUNDER developed by Langley Research Center exhibits high power when it is used as an energy generator and large displacement when it is used as an actuator. Compared to the less flexible PZT, although THUNDER is more difficult to model, THUNDER has better vibration absorption capacity and higher energy recovery efficiency. The effect of the THUNDER’s radius of curvature on energy harvesting efficiency is mainly investigated. We set the THUNDER’s radius of curvature as a dynamic tuning parameter which can tune the piezoelectric generators’ frequency with the source excitation frequency.

  6. Repair of segmental bone defects with bone marrow and BMP-2 adenovirus in the rabbit radius

    NASA Astrophysics Data System (ADS)

    Cheng, Lijia; Lu, Xiaofeng; Shi, Yujun; Li, Li; Xue, Jing; Zhang, Li; Xia, Jie; Wang, Yujia; Zhang, Xingdong; Bu, Hong

    2012-12-01

    Bone tissue engineering (BTE) is approached via implantation of autogenous mesenchymal stem cells (MSCs), marrow cells, or platelet-rich plasma, etc. To the contrary, gene therapy combining with the bone marrow (BM) has not been often reported. This study was performed to investigate whether a modified BTE method, that is, the BM and a recombinant human bone morphogenetic protein-2 adenovirus (Ad.hBMP-2) gene administering in hydroxyapatite/β-tricalcium phosphate (HA/β-TCP) ceramics could accelerate the healing of segmental defects in the rabbit radius. In our study, ceramics were immersed in the adenovirus overnight, and half an hour before surgery, autologous BM aspirates were thoroughly mixed with the ceramics; at the same time, a 15-mm radius defect was introduced in the bilateral forelimbs of all animals, after that, this defect was filled with the following: (1) Ad.hBMP-2 + HA/β-TCP + autologous BM (group 1); (2) HA/β-TCP + Ad.hBMP-2 (group 2); (3) HA/β-TCP alone (group 3); (4) an empty defect as a control (group 4). Histological observation and μ-CT analyses were performed on the specimens at weeks 2, 4, 8, and 12, respectively. In group 1, new bone was observed at week 4 and BM appeared at week 12, in groups 2 and 3, new bone was observed at week 8 and it was more mature at week 12, in contrast, the defect was not bridged in group 4 at week 12. The new bone area percentage in group 1 was significantly higher than that in groups 2 and 3. Our study indicated that BM combined with hBMP-2 adenovirus and porous ceramics could significantly increase the amount of newly formed bone. And this modified BTE method thus might have potentials in future clinical application.

  7. Importance of Radius of Influence and its Estimation in a Limestone Quarry

    NASA Astrophysics Data System (ADS)

    Soni, A. K.; Sahoo, L. K.; Ghosh, U. K.; Khond, M. V.

    2015-04-01

    Limestone mining at Lanjiberna limestone and dolomite quarry has created positive as well negative impacts on ground water. With further deepening of the mine, drawdown trend (negative effect) is observed and at the same time ground water recharge of the order of 4,527.48 m3/day, through mine pits (positive impact) is noticed. The aquifer present in the area is unconfined and mainly consists of weathered quartzite, phyllites, limestone and dolomite. To know the cumulative impact of mining on surroundings, the effective radius of influence (Re) for excavated mine area is calculated as 1,059 m. Here, it may be noted that three `concentric working pits' (Pit No. 2 & 6; Pit no 1 & 3 and Pit No 4 & 5) produces limestone at this mine and the pit-wise radius of influence (Ro) is estimated. Value of Ro for Pit-2 & 6 is 612.14 m; Pit-1 & 3 is 475 m and Pit-4 & 5 is 384.15 m. Its average i.e., Ro (for all three pits, cumulative) is estimated as 490 m. From this typical case study and estimation of Ro and Re values, it is concluded that the maximum and minimum value of overall impact/influence lies in between 0.49 and 1.05 km. These estimated values of `area of influence' are less compared to the whole mine lease area values. Local aquifer, which lies at shallower as well as at deeper depth had behaved consistently with respect to recharge and drawdown conditions. Thus, assessment of Ro and Re is extremely helpful for `integrated mine planning' to achieve targeted production, economically with minimum interruptions.

  8. Effective pore size and radius of capture for K(+) ions in K-channels.

    PubMed

    Moldenhauer, Hans; Díaz-Franulic, Ignacio; González-Nilo, Fernando; Naranjo, David

    2016-01-01

    Reconciling protein functional data with crystal structure is arduous because rare conformations or crystallization artifacts occur. Here we present a tool to validate the dimensions of open pore structures of potassium-selective ion channels. We used freely available algorithms to calculate the molecular contour of the pore to determine the effective internal pore radius (r(E)) in several K-channel crystal structures. r(E) was operationally defined as the radius of the biggest sphere able to enter the pore from the cytosolic side. We obtained consistent r(E) estimates for MthK and Kv1.2/2.1 structures, with r(E) = 5.3-5.9 Å and r(E) = 4.5-5.2 Å, respectively. We compared these structural estimates with functional assessments of the internal mouth radii of capture (r(C)) for two electrophysiological counterparts, the large conductance calcium activated K-channel (r(C) = 2.2 Å) and the Shaker Kv-channel (r(C) = 0.8 Å), for MthK and Kv1.2/2.1 structures, respectively. Calculating the difference between r(E) and r(C), produced consistent size radii of 3.1-3.7 Å and 3.6-4.4 Å for hydrated K(+) ions. These hydrated K(+) estimates harmonize with others obtained with diverse experimental and theoretical methods. Thus, these findings validate MthK and the Kv1.2/2.1 structures as templates for open BK and Kv-channels, respectively. PMID:26831782

  9. Effective pore size and radius of capture for K+ ions in K-channels

    PubMed Central

    Moldenhauer, Hans; Díaz-Franulic, Ignacio; González-Nilo, Fernando; Naranjo, David

    2016-01-01

    Reconciling protein functional data with crystal structure is arduous because rare conformations or crystallization artifacts occur. Here we present a tool to validate the dimensions of open pore structures of potassium-selective ion channels. We used freely available algorithms to calculate the molecular contour of the pore to determine the effective internal pore radius (rE) in several K-channel crystal structures. rE was operationally defined as the radius of the biggest sphere able to enter the pore from the cytosolic side. We obtained consistent rE estimates for MthK and Kv1.2/2.1 structures, with rE = 5.3–5.9 Å and rE = 4.5–5.2 Å, respectively. We compared these structural estimates with functional assessments of the internal mouth radii of capture (rC) for two electrophysiological counterparts, the large conductance calcium activated K-channel (rC = 2.2 Å) and the Shaker Kv-channel (rC = 0.8 Å), for MthK and Kv1.2/2.1 structures, respectively. Calculating the difference between rE and rC, produced consistent size radii of 3.1–3.7 Å and 3.6–4.4 Å for hydrated K+ ions. These hydrated K+ estimates harmonize with others obtained with diverse experimental and theoretical methods. Thus, these findings validate MthK and the Kv1.2/2.1 structures as templates for open BK and Kv-channels, respectively. PMID:26831782

  10. Effects of Nose Radius and Aerodynamic Loading on Leading Edge Receptivity

    NASA Technical Reports Server (NTRS)

    Hammerton, P. W.; Kerschen, E. J.

    1998-01-01

    An analysis is presented of the effects of airfoil thickness and mean aerodynamic loading on boundary-layer receptivity in the leading-edge region. The case of acoustic free-stream disturbances, incident on a thin cambered airfoil with a parabolic leading edge in a low Mach number flow, is considered. An asymptotic analysis based on large Reynolds number is developed, supplemented by numerical results. The airfoil thickness distribution enters the theory through a Strouhal number based on the nose radius of the airfoil, S = (omega)tau(sub n)/U, where omega is the frequency of the acoustic wave and U is the mean flow speed. The influence of mean aerodynamic loading enters through an effective angle-of-attack parameter ti, related to flow around the leading edge from the lower surface to the upper. The variation of the receptivity level is analyzed as a function of S, mu, and characteristics of the free-stream acoustic wave. For an unloaded leading edge, a finite nose radius dramatically reduces the receptivity level compared to that for a flat plate, the amplitude of the instability waves in the boundary layer being decreased by an order of magnitude when S = 0.3. Modest levels of aerodynamic loading are found to further decrease the receptivity level for the upper surface of the airfoil, while an increase in receptivity level occurs for the lower surface. For larger angles of attack close to the critical angle for boundary layer separation, a local rise in the receptivity level occurs for the upper surface, while for the lower surface the receptivity decreases. The effects of aerodynamic loading are more pronounced at larger values of S. Oblique acoustic waves produce much higher receptivity levels than acoustic waves propagating downstream parallel to the airfoil chord.

  11. The Hα surface brightness-radius relation: a robust statistical distance indicator for planetary nebulae

    NASA Astrophysics Data System (ADS)

    Frew, David J.; Parker, Q. A.; Bojičić, I. S.

    2016-01-01

    Measuring the distances to Galactic planetary nebulae (PNe) has been an intractable problem for many decades. We have now established a robust optical statistical distance indicator, the Hα surface brightness-radius or SHα-r relation, which addresses this problem. We developed this relation from a critically evaluated sample of primary calibrating PNe. The robust nature of the method results from our revised calibrating distances with significantly reduced systematic uncertainties, and the recent availability of high-quality data, including updated nebular diameters and integrated Hα fluxes. The SHα-r technique is simple in its application, requiring only an angular size, an integrated Hα flux, and the reddening to the PN. From these quantities, an intrinsic radius is calculated, which when combined with the angular size, yields the distance directly. Furthermore, we have found that optically thick PNe tend to populate the upper bound of the trend, while optically thin PNe fall along the lower boundary in the SHα-r plane. This enables sub-trends to be developed which offer even better precision in the determination of distances, as good as 18 per cent in the case of optically thin, high-excitation PNe. This is significantly better than any previous statistical indicator. We use this technique to create a catalogue of statistical distances for over 1100 Galactic PNe, the largest such compilation in the literature to date. Finally, in an appendix, we investigate both a set of transitional PNe and a range of PN mimics in the SHα-r plane, to demonstrate its use as a diagnostic tool. Interestingly, stellar ejecta around massive stars plot on a tight locus in SHα-r space with the potential to act as a separate distance indicator for these objects.

  12. Critical Radius of Supercooled Water Droplets: On the Transition toward Dendritic Freezing.

    PubMed

    Buttersack, Tillmann; Bauerecker, Sigurd

    2016-01-28

    The freezing of freely suspended supercooled water droplets with a diameter of bigger than a few micrometers splits into two rather different freezing stages. Within the first very fast dendritic freezing stage a spongy network ice with an ice portion of less than one-third forms and more than two-thirds of liquid water remain. In the present work the distribution of the ice portion in the droplet directly after the dendritic freezing phase as well as the evolution of the ice and temperature distribution has been investigated in dependence of the most relevant parameters as droplet diameter, dendritic freezing velocity (which correlates with the supercooling) and heat transfer coefficient to the surroundings (which correlates with the relative droplet velocity compared to the ambient air and with the droplet size). For this purpose on the experimental side acoustically levitated droplets in climate chambers have been investigated in combination with high-speed cameras. The obtained results have been used for finite element method (FEM) simulations of the dendritic freezing phase under consideration of the beginning second, much slower heat-transfer dominated freezing phase. A theoretical model covering 30 layers and 5 shells of the droplet has been developed which allows one to describe the evolution of both freezing phases at the same time. The simulated results are in good agreement with experimental as well as with calculated results exploiting the heat balance equation. The most striking result of this work is the critical radius of the droplet which describes the transition of one-stage freezing of the supercooled water droplet toward the thermodynamically forced dendritical two-stage freezing in which the droplet cannot sufficiently get rid of the formation heat anymore. Depending on the parameters named above this critical radius was found to be in the range of 0.1 to 1 μm by FEM simulation.

  13. THE LOW-LUMINOSITY END OF THE RADIUS-LUMINOSITY RELATIONSHIP FOR ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Bentz, Misty C.; Denney, Kelly D.; Vestergaard, Marianne; Grier, Catherine J.; Peterson, Bradley M.; De Rosa, Gisella; Pogge, Richard W.; Barth, Aaron J.; Bennert, Vardha N.; Canalizo, Gabriela; Filippenko, Alexei V.; Li Weidong; Gates, Elinor L.; Malkan, Matthew A.; Stern, Daniel; Treu, Tommaso; Woo, Jong-Hak

    2013-04-20

    We present an updated and revised analysis of the relationship between the H{beta} broad-line region (BLR) radius and the luminosity of the active galactic nucleus (AGN). Specifically, we have carried out two-dimensional surface brightness decompositions of the host galaxies of nine new AGNs imaged with the Hubble Space Telescope Wide Field Camera 3. The surface brightness decompositions allow us to create ''AGN-free'' images of the galaxies, from which we measure the starlight contribution to the optical luminosity measured through the ground-based spectroscopic aperture. We also incorporate 20 new reverberation-mapping measurements of the H{beta} time lag, which is assumed to yield the average H{beta} BLR radius. The final sample includes 41 AGNs covering four orders of magnitude in luminosity. The additions and updates incorporated here primarily affect the low-luminosity end of the R{sub BLR}-L relationship. The best fit to the relationship using a Bayesian analysis finds a slope of {alpha}= 0.533{sup +0.035}{sub -0.033}, consistent with previous work and with simple photoionization arguments. Only two AGNs appear to be outliers from the relationship, but both of them have monitoring light curves that raise doubt regarding the accuracy of their reported time lags. The scatter around the relationship is found to be 0.19 {+-} 0.02 dex, but would be decreased to 0.13 dex by the removal of these two suspect measurements. A large fraction of the remaining scatter in the relationship is likely due to the inaccurate distances to the AGN host galaxies. Our results help support the possibility that the R{sub BLR}-L relationship could potentially be used to turn the BLRs of AGNs into standardizable candles. This would allow the cosmological expansion of the universe to be probed by a separate population of objects, and over a larger range of redshifts.

  14. Detection of the Splashback Radius and Halo Assembly Bias of Massive Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    More, Surhud; Miyatake, Hironao; Takada, Masahiro; Diemer, Benedikt; Kravtsov, Andrey V.; Dalal, Neal K.; More, Anupreeta; Murata, Ryoma; Mandelbaum, Rachel; Rozo, Eduardo; Rykoff, Eli S.; Oguri, Masamune; Spergel, David N.

    2016-07-01

    We show that the projected number density profiles of Sloan Digital Sky Survey photometric galaxies around galaxy clusters display strong evidence for the splashback radius, a sharp halo edge corresponding to the location of the first orbital apocenter of satellite galaxies after their infall. We split the clusters into two subsamples with different mean projected radial distances of their members, < {R}{{mem}}> , at fixed richness and redshift. The sample with smaller < {R}{{mem}}> has a smaller ratio of the splashback radius to the traditional halo boundary {R}{{200m}} than the subsample with larger < {R}{{mem}}> , indicative of different mass accretion rates for these subsamples. The same subsamples were recently used by Miyatake et al. to show that their large-scale clustering differs despite their similar weak lensing masses, demonstrating strong evidence for halo assembly bias. We expand on this result by presenting a 6.6σ difference in the clustering amplitudes of these samples using cluster-photometric galaxy cross-correlations. This measurement is a clear indication that halo clustering depends on parameters other than halo mass. If < {R}{{mem}}> is related to the mass assembly history of halos, the measurement is a manifestation of the halo assembly bias. However, our measured splashback radii are smaller, while the strength of the assembly bias signal is stronger, than the predictions of collisionless Λ cold dark matter simulations. We show that dynamical friction, cluster mis-centering, or projection effects are not likely to be the sole source of these discrepancies. However, further investigations regarding unknown catastrophic weak lensing or cluster identification systematics are warranted.

  15. ON THE CONSISTENCY OF NEUTRON-STAR RADIUS MEASUREMENTS FROM THERMONUCLEAR BURSTS

    SciTech Connect

    Galloway, Duncan K.; Lampe, Nathanael

    2012-03-01

    The radius of neutron stars can in principle be measured via the normalization of a blackbody fitted to the X-ray spectrum during thermonuclear (type-I) X-ray bursts, although few previous studies have addressed the reliability of such measurements. Here we examine the apparent radius in a homogeneous sample of long, mixed H/He bursts from the low-mass X-ray binaries GS 1826-24 and KS 1731-26. The measured blackbody normalization (proportional to the emitting area) in these bursts is constant over a period of up to 60 s in the burst tail, even though the flux (blackbody temperature) decreased by a factor of 60%-75% (30%-40%). The typical rms variation in the mean normalization from burst to burst was 3%-5%, although a variation of 17% was found between bursts observed from GS 1826-24 in two epochs. A comparison of the time-resolved spectroscopic measurements during bursts from the two epochs shows that the normalization evolves consistently through the burst rise and peak, but subsequently increases further in the earlier epoch bursts. The elevated normalization values may arise from a change in the anisotropy of the burst emission or alternatively variations in the spectral correction factor, f{sub c} , of order 10%. Since burst samples observed from systems other than GS 1826-24 are more heterogeneous, we expect that systematic uncertainties of at least 10% are likely to apply generally to measurements of neutron-star radii, unless the effects described here can be corrected for.

  16. Radius exponent in elastic and rigid arterial models optimized by the least energy principle

    PubMed Central

    Nakamura, Yoshihiro; Awa, Shoichi

    2014-01-01

    Abstract It was analyzed in normal physiological arteries whether the least energy principle would suffice to account for the radius exponent x. The mammalian arterial system was modeled as two types, the elastic or the rigid, to which Bernoulli's and Hagen‐Poiseuille's equations were applied, respectively. We minimized the total energy function E, which was defined as the sum of kinetic, pressure, metabolic and thermal energies, and loss of each per unit time in a single artery transporting viscous incompressible blood. Assuming a scaling exponent α between the vessel radius (r) and length (l) to be 1.0, x resulted in 2.33 in the elastic model. The rigid model provided a continuously changing x from 2.33 to 3.0, which corresponded to Uylings’ and Murray's theories, respectively, through a function combining Reynolds number with a proportional coefficient of the l − r relationship. These results were expanded to an asymmetric arterial fractal tree with the blood flow preservation rule. While x in the optimal elastic model accounted for around 2.3 in proximal systemic (r >1 mm) and whole pulmonary arteries (r ≥0.004 mm), optimal x in the rigid model explained 2.7 in elastic‐muscular (0.1 < r ≤1 mm) and 3.0 in peripheral resistive systemic arteries (0.004 ≤ r ≤0.1 mm), in agreement with data obtained from angiographic, cast‐morphometric, and in vivo experimental studies in the literature. The least energy principle on the total energy basis provides an alternate concept of optimality relating to mammalian arterial fractal dimensions under α = 1.0. PMID:24744905

  17. EVIDENCE FOR A SNOW LINE BEYOND THE TRANSITIONAL RADIUS IN THE TW Hya PROTOPLANETARY DISK

    SciTech Connect

    Zhang, K.; Pontoppidan, K. M.; Salyk, C.; Blake, G. A.

    2013-04-01

    We present an observational reconstruction of the radial water vapor content near the surface of the TW Hya transitional protoplanetary disk, and report the first localization of the snow line during this phase of disk evolution. The observations are comprised of Spitzer-IRS, Herschel-PACS, and Herschel-HIFI archival spectra. The abundance structure is retrieved by fitting a two-dimensional disk model to the available star+disk photometry and all observed H{sub 2}O lines, using a simple step-function parameterization of the water vapor content near the disk surface. We find that water vapor is abundant ({approx}10{sup -4} per H{sub 2}) in a narrow ring, located at the disk transition radius some 4 AU from the central star, but drops rapidly by several orders of magnitude beyond 4.2 AU over a scale length of no more than 0.5 AU. The inner disk (0.5-4 AU) is also dry, with an upper limit on the vertically averaged water abundance of 10{sup -6} per H{sub 2}. The water vapor peak occurs at a radius significantly more distant than that expected for a passive continuous disk around a 0.6 M{sub Sun} star, representing a volatile distribution in the TW Hya disk that bears strong similarities to that of the solar system. This is observational evidence for a snow line that moves outward with time in passive disks, with a dry inner disk that results either from gas giant formation or gas dissipation and a significant ice reservoir at large radii. The amount of water present near the snow line is sufficient to potentially catalyze the (further) formation of planetesimals and planets at distances beyond a few AU.

  18. Weak charge form factor and radius of 208Pb through parity violation in electron scattering

    SciTech Connect

    Horowitz, C. J.; Ahmed, Z.; Jen, C. -M.; Rakhman, A.; Souder, P. A.; Dalton, M. M.; Liyanage, N.; Paschke, K. D.; Saenboonruang, K.; Silwal, R.; Franklin, G. B.; Friend, M.; Quinn, B.; Kumar, K. S.; McNulty, D.; Mercado, L.; Riordan, S.; Wexler, J.; Michaels, R. W.; Urciuoli, G. M.

    2012-03-26

    We use distorted wave electron scattering calculations to extract the weak charge form factor FW($\\bar{q}$), the weak charge radius RW, and the point neutron radius Rn, of 208Pb from the PREX parity violating asymmetry measurement. The form factor is the Fourier transform of the weak charge density at the average momentum transfer $\\bar{q}$ = 0.475 fm-1. We find FW($\\bar{q}$) = 0.204 ± 0.028(exp) ± 0.001(model). We use the Helm model to infer the weak radius from FW($\\bar{q}$). We find RW = 5.826 ± 0.181(exp) ± 0.027(model) fm. Here the exp error includes PREX statistical and systematic errors, while the model error describes the uncertainty in RW from uncertainties in the surface thickness σ of the weak charge density. The weak radius is larger than the charge radius, implying a 'weak charge skin' where the surface region is relatively enriched in weak charges compared to (electromagnetic) charges. We extract the point neutron radius Rn = 5.751 ± 0.175 (exp) ± 0.026(model) ± 0.005(strange) fm, from RW. Here there is only a very small error (strange) from possible strange quark contributions. We find Rn to be slightly smaller than RW because of the nucleon's size. As a result, we find a neutron skin thickness of Rn-Rp = 0.302 ± 0.175 (exp) ± 0.026 (model) ± 0.005 (strange) fm, where Rp is the point proton radius.

  19. Dearth of short-period Neptunian exoplanets: A desert in period-mass and period-radius planes

    NASA Astrophysics Data System (ADS)

    Mazeh, T.; Holczer, T.; Faigler, S.

    2016-05-01

    A few studies have reported a significant dearth of exoplanets with Neptune mass and radius with orbital periods below 2-4 d. This cannot be explained by observational biases because many Neptunian planets with longer orbital periods have been detected. The existence of this desert is similar to the appearance of the so-called brown-dwarf desert that suggests different formation mechanisms of planets and stellar companions with short orbital periods. Similarly, the Neptunian desert might indicate different mechanisms of formation and evolution for hot Jupiters and short-period super-Earths. We here follow a previous study and examine the location and shape of the desert in both the period-mass and period-radius planes, using the currently available large samples of planets. The desert in the period-mass plane has a relatively sharp upper edge, with a planetary mass that is inversely proportional to the planetary orbital period, while the lower, somewhat blurred, boundary is located along masses that are apparently linearly proportional to the period. The desert in the period-radius plane of the transiting planets is less clear. It seems as if the radius along the upper boundary is inversely proportional to the period to the power of one-third, while the lower boundary shows a radius that is proportional to the period to the power of two-thirds. The combination of the two upper bounds of the desert, in the period-mass and period-radius planes, yields a planetary mass-radius relation of Rp/RJup ≃ (1.2 ± 0.3)(Mp/MJup)0.27 ± 0.11 for 0.1 ≲ Mp/MJup ≲ 1. The derived shape of the desert, which might extend up to periods of 5-10 d, could shed some light on the formation and evolution of close-in planets.

  20. Bone mineral density of the spine and radius shaft in children with X-linked hypophosphatemic rickets (XLH).

    PubMed

    Oliveri, M B; Cassinelli, H; Bergadá, C; Mautalen, C A

    1991-02-01

    X-linked hypophosphatemic rickets (XLH) is characterized by inadequate skeletal mineralization. The bone mineral density (BMD) of the radius shaft and the lumbar spine was determined in 13 children with XLH. Ten patients were on treatment, whereas three patients had discontinued treatment 20-32 months prior to this study. Two of them had radiological evidence of rickets. The radius shaft BMD was significantly diminished: Z score was -1.33 +/- 0.89 (P less than 0.001), while the BMD of lumbar spine was significantly augmented (Z score +1.95 +/- 1.17, P less than 0.001). A positive correlation was found between the Z scores for the BMD of the radius shaft and spine. The two patients with overt rickets had lower radius shaft BMD values and a lesser increment of BMD of the spine. The BMD deficit of cortical bone may be related to the lack of efficacy of the treatment and/or to an intrinsic defect of the bone on this disease. On the other hand, the augmented BMD of the lumbar spine might reflect the overabundance of partially mineralized osteoid. The determination of the BMD of the radius shaft by SPA was a sensitive method for detecting abnormalities of the bone mass in XLH patients under treatment without radiological signs of rickets.

  1. THE BEHAVIOR OF THE 17 GHz SOLAR RADIUS AND LIMB BRIGHTENING IN THE SPOTLESS MINIMUM XXIII/XXIV

    SciTech Connect

    Selhorst, C. L.; Gimenez de Castro, C. G.; Valio, A.; Costa, J. E. R.; Shibasaki, K.

    2011-06-10

    The current solar minimum has surprised the entire solar community because the spotless period is presently almost 2-3 years longer than the usual minima. To better understand this, we studied the variation of the solar radius and the polar limb brightening at 17 GHz, comparing the results from the minimum at the end of cycle XXIII with those of the previous one. Daily maps obtained by the Nobeyama Radioheliograph (NoRH) from 1992 through 2010 were analyzed. Whereas the variation of the solar radius at radio frequencies indicates the heating of the solar atmosphere due to solar activity, the limb brightening intensity depends on the organization of the polar magnetic field of the Sun, including the global dipole and the features formed around it. These features are more prominent during minima periods. As a common result, researchers have observed a decrease in both radius and limb brightness intensity at 17 GHz during the present minimum when compared with the previous one. The mean solar radius is 0.''9 {+-} 0.''6 smaller and the limb brightening reduced its intensity by around 20%. Both decrements are interpreted in terms of the weaker solar chromospheric activity of the present cycle. Measurement of the radius and limb brightening at 17 GHz can be used as an alternative solar activity index and should be included in the set of parameters used to predict future cycles.

  2. Tailored ion radius distribution for increased dynamic range in FT-ICR mass analysis of complex mixtures.

    PubMed

    Kaiser, Nathan K; McKenna, Amy M; Savory, Joshua J; Hendrickson, Christopher L; Marshall, Alan G

    2013-01-01

    Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) typically utilizes an m/z-independent excitation magnitude to excite all ions to the same cyclotron radius, so that the detected signal magnitude is directly proportional to the relative ion abundance. However, deleterious space charge interaction between ion clouds is maximized for clouds of equal radius. To minimize ion cloud interactions, we induce an m/z-dependent ion radius distribution (30%-45% of the maximum cell radius) that results in a 3-fold increase in mass spectral dynamic range for complex mixtures, consistent with increased ion cloud lifetime for less-abundant ion clouds. Further, broadband frequency-sweep (chirp) excitation that contains the second and/or third harmonic frequency of an excited ion cloud swept from low-to-high frequency produces systematic variations in accurate mass measurement not observed when the sweep direction is reversed. The ion cyclotron radius distribution induces an m/z-dependent frequency shift that can be corrected to provide a root-mean-square (rms) mass measurement error of <100 ppb on petroleum-based mixtures that contain tens of thousands of identified peaks.

  3. THE MASS OF KOI-94d AND A RELATION FOR PLANET RADIUS, MASS, AND INCIDENT FLUX

    SciTech Connect

    Weiss, Lauren M.; Marcy, Geoffrey W.; Isaacson, Howard; Kolbl, Rea; Rowe, Jason F.; Howell, Steve B.; Howard, Andrew W.; Fortney, Jonathan J.; Miller, Neil; Demory, Brice-Olivier; Seager, Sara; Fischer, Debra A.; Adams, Elisabeth R.; Dupree, Andrea K.; Johnson, John Asher; Horch, Elliott P.; Everett, Mark E.; Fabrycky, Daniel C.

    2013-05-01

    We measure the mass of a modestly irradiated giant planet, KOI-94d. We wish to determine whether this planet, which is in a 22 day orbit and receives 2700 times as much incident flux as Jupiter, is as dense as Jupiter or rarefied like inflated hot Jupiters. KOI-94 also hosts at least three smaller transiting planets, all of which were detected by the Kepler mission. With 26 radial velocities of KOI-94 from the W. M. Keck Observatory and a simultaneous fit to the Kepler light curve, we measure the mass of the giant planet and determine that it is not inflated. Support for the planetary interpretation of the other three candidates comes from gravitational interactions through transit timing variations, the statistical robustness of multi-planet systems against false positives, and several lines of evidence that no other star resides within the photometric aperture. We report the properties of KOI-94b (M{sub P} = 10.5 {+-} 4.6 M{sub Circled-Plus }, R{sub P} = 1.71 {+-} 0.16 R{sub Circled-Plus }, P = 3.74 days), KOI-94c (M{sub P} = 15.6{sup +5.7}{sub -15.6} M{sub Circled-Plus }, R{sub P} = 4.32 {+-} 0.41 R{sub Circled-Plus }, P = 10.4 days), KOI-94d (M{sub P} = 106 {+-} 11 M{sub Circled-Plus }, R{sub P} = 11.27 {+-} 1.06 R{sub Circled-Plus }, P = 22.3 days), and KOI-94e (M{sub P} = 35{sup +18}{sub -28} M{sub Circled-Plus }, R{sub P} = 6.56 {+-} 0.62 R{sub Circled-Plus }, P = 54.3 days). The radial velocity analyses of KOI-94b and KOI-94e offer marginal (>2{sigma}) mass detections, whereas the observations of KOI-94c offer only an upper limit to its mass. Using the KOI-94 system and other planets with published values for both mass and radius (138 exoplanets total, including 35 with M{sub P} < 150 M{sub Circled-Plus }), we establish two fundamental planes for exoplanets that relate their mass, incident flux, and radius from a few Earth masses up to 13 Jupiter masses: (R{sub P}/R{sub Circled-Plus }) = 1.78(M{sub P}/M{sub Circled-Plus }){sup 0.53}(F/erg s{sup -1} cm

  4. Multi-Segment Radius Measurement Using an Absolute Distance Meter Through a Null Assembly

    NASA Technical Reports Server (NTRS)

    Merle, Cormic; Wick, Eric; Hayden, Joseph

    2011-01-01

    This system was one of the test methods considered for measuring the radius of curvature of one or more of the 18 segmented mirrors that form the 6.5 m diameter primary mirror (PM) of the James Webb Space Telescope (JWST). The assembled telescope will be tested at cryogenic temperatures in a 17-m diameter by 27-m high vacuum chamber at the Johnson Space Center. This system uses a Leica Absolute Distance Meter (ADM), at a wavelength of 780 nm, combined with beam-steering and beam-shaping optics to make a differential distance measurement between a ring mirror on the reflective null assembly and individual PM segments. The ADM is located inside the same Pressure-Tight Enclosure (PTE) that houses the test interferometer. The PTE maintains the ADM and interferometer at ambient temperature and pressure so that they are not directly exposed to the telescope s harsh cryogenic and vacuum environment. This system takes advantage of the existing achromatic objective and reflective null assembly used by the test interferometer to direct four ADM beamlets to four PM segments through an optical path that is coincident with the interferometer beam. A mask, positioned on a linear slide, contains an array of 1.25 mm diameter circular subapertures that map to each of the 18 PM segments as well as six positions around the ring mirror. A down-collimated 4 mm ADM beam simultaneously covers 4 adjacent PM segment beamlets and one ring mirror beamlet. The radius, or spacing, of all 18 segments can be measured with the addition of two orthogonally-oriented scanning pentaprisms used to steer the ADM beam to any one of six different sub-aperture configurations at the plane of the ring mirror. The interferometer beam, at a wavelength of 687 nm, and the ADM beamlets, at a wavelength of 780 nm, pass through the objective and null so that the rays are normally incident on the parabolic PM surface. After reflecting off the PM, both the ADM and interferometer beams return to their respective

  5. Axial Length/Corneal Radius of Curvature Ratio and Myopia in 3-Year-Old Children

    PubMed Central

    Foo, Valencia Hui Xian; Verkicharla, Pavan Kumar; Ikram, Mohammad Kamran; Chua, Sharon Yu Lin; Cai, Shirong; Tan, Chuen Seng; Chong, Yap-Seng; Kwek, Kenneth; Gluckman, Peter; Wong, Tien-Yin; Ngo, Cheryl; Saw, Seang-Mei; on behalf of the GUSTO study group

    2016-01-01

    Purpose This study investigated the association of axial length (AL) to corneal radius of curvature (CRC) ratio with spherical equivalent (SE) in a 3-year old Asian cohort. Methods Three-hundred forty-nine 3-year old Asian children from The Growing Up in Singapore towards Healthy Outcomes (GUSTO) birth cohort study underwent AL and CRC measurements with a noncontact ocular biometer and cycloplegic refraction using an autorefractor. The ratio of AL to CRC (AL/CRC) was calculated for all the participants, and subsequently AL, CRC, and AL/CRC were analyzed in relationship to SE. Results The SE showed better correlation with AL/CRC (Spearman's correlation coefficient, ρ = −0.53; 95% confidence interval [CI]: −0.66; −0.49; P < 0.001) compared to either AL or CRC alone ([ρ = −0.36; 95% CI: −0.51 to 0.51; P = 0.01] and [ρ = 0.05; 95% CI: −0.04 to 0.17; P = 0.34], respectively). Mean AL/CRC was 2.91 ± 0.06 among myopes and decreased to 2.79 ± 0.06 among hyperopes. Axial length to corneal radius of curvature was strongly correlated with SE in myopes (ρ = −0.78; 95% CI: −3.76; −0.79; P = < 0.001), but not in emmetropes and hyperopes ([ρ = −0.39; 95% CI: −10.73; −0.57; P = 0.01] and [ρ = −0.18; 95% CI: −17.28; 12.42; P = 0.38], respectively). Linear regression adjusted for gender and ethnicity showed a 0.74-diopter shift in SE towards myopia with every 0.1 increase in AL/CRC ratio (P < 0.001, r2 = 0.33). Conclusion The correlation between SE and AL/CRC is stronger than that between AL or CRC alone. This suggests that in a research setting, when cycloplegic refraction is difficult to perform on 3-year-old children, AL/CRC may be the next best reference for refractive error. Translational Relevance In the research setting, AL/CRC may be the next best reference for refractive error over AL alone when cycloplegic refraction is unavailable in 3-year old children. PMID:26929885

  6. Linear stability of spiral and annular Poiseuille flow for small radius ratio

    NASA Astrophysics Data System (ADS)

    Cotrell, David L.; Pearlstein, Arne J.

    For the radius ratio η ≡ R_i/R_o = 0.1 and several rotation rate ratios μ ≡ Ω_o/Ω_i, we consider the linear stability of spiral Poiseuille flow (SPF) up to Re = 10^5, where R_i and R_o are the radii of the inner and outer cylinders, respectively, Re ≡ overline V_Z(R_o -R_i)/ν is the Reynolds number, Ω_i and Ω_o are the (signed) angular speeds of the inner and outer cylinders, respectively, ν is the kinematic viscosity, and overline V_Z is the mean axial velocity. The Re range extends more than three orders of magnitude beyond that considered in the previous μ = 0 work of Recktenwald et al. (Phys. Rev. E, vol. 48, 1993, p. 444). We show that in the non-rotating limit of annular Poiseuille flow, linear instability does not occur below a critical radius ratio hat η ≈ 0.115. We also establish the connection of the linear stability of annular Poiseuille flow for 0 < η ≤ hat η at all Re to the linear stability of circular Poiseuille flow (η = 0) at all Re. For the rotating case, with μ = -1, - 0.5, - 0.25, 0 and 0.2, the stability boundaries, presented in terms of critical Taylor number Ta ≡ Ω_i(R_o -R_i)^2/ν versus Re, show that the results are qualitatively different from those at larger η. For each μ, the centrifugal instability at small Re does not connect to a high-Re Tollmien Schlichting-like instability of annular Poiseuille flow, since the latter instability does not exist for η < hatη. We find a range of Re for which disconnected neutral curves exist in the k Ta plane, which for each non-zero μ considered, lead to a multi-valued stability boundary, corresponding to two disjoint ranges of stable Ta. For each counter-rotating (μ < 0) case, there is a finite range of Re for which there exist three critical values of Ta, with the upper branch emanating from the Re = 0 instability of Couette flow. For the co-rotating (μ = 0.2) case, there are two critical values of Ta for each Re in an apparently semi-infinite range of Re, with

  7. [Possible applications of pedicled vascularized bone transplants of the distal radius].

    PubMed

    Sauerbier, M; Bishop, A T

    2001-11-01

    Reverse-flow pedicle vascularized bone grafts (VBGs) from the distal radius may be used for the surgical treatment of carpal fracture nonunions and avascular necrosis. Such grafts remain viable with quantifiable blood flow as demonstrated in a recent canine experiment. In this paper, the vascular anatomy of the distal radius is demonstrated and the surgical technique of VBG harvest is described. Our indications and results for treatment of scaphoid nonunion and Kienböck's disease are discussed and compared with the current literature. Fifteen patients with scaphoid nonunion and nine patients with Kienböck's disease stage IIIa were treated by reverse-flow pedicled VBG. Range of motion and grip strength were measured postoperatively and compared to the contralateral hand in all patients. An outcome questionnaire was used to measure patient's satisfaction and ADL's in the patients with Kienböck's disease. The radiologic diagnostic was performed with conventional X-rays, trispiral tomograms and MRI. In the scaphoid nonunion group, all patients were male, with an average age of 27.6 years. Five patients had prior attempts of autogenous bone grafting which failed. Six patients had a radiographic suggestion of proximal fragment avascular necrosis. All scaphoids healed. Time to union was 11.1 weeks on average. Average follow-up was 36.2 months. Pain relief, range of motion and grip strength were very promising. The treatment of Kienböck's disease was also promising in nine patients. Mean patient age was 31 years, and follow-up averaged 32 months. Six patients had complete pain relief, and three had occasional pain. Grip strength reached 86% of the contralateral side (a 25% improvement from preoperative values). Postoperative MRI demonstrated progressive revascularization with time. The results of treating scaphoid nonunions are promising. The use of vascularized bone graft facilitates rapid, reliable union of established scaphoid nonunion, even with proximal location

  8. The effects of meter orientation downstream of a short radius elbow on electromagnetic flow meters

    NASA Astrophysics Data System (ADS)

    Justensen, Jared C.

    Electromagnetic flowmeters (known as magnetic flow meters) are a widely used type of flowmeter. The accuracy of magnetic flow meters are a function of several factors, not the least of which is the flow condition inside the pipe. It has been shown that disturbances in the velocity profile affects the accuracy of a magnetic flow meter (Luntta, 1998). Accordingly, manufacturers of magnetic flow meters give installation guidelines. These guidelines help prevent the user from installing the meter in a pipe configuration that is likely to cause the meter to produce inaccurate results. Although most manufacturers provide recommendations about the amount of straight pipe that is necessary upstream of the meter, little is said about the orientation of the meter in relation to upstream disturbances. This study examines the performance of magnetic flow meters when positioned at two different orientations: EIP (electrodes in plane with an upstream 90-degree short radius elbow) and EOP (electrodes out of plane). Four different meters were included in the study in which a baseline straight pipe test was first performed using over fifty diameters of straight pipe upstream of each meter. The straight pipe test was used to determine the baseline accuracy of each of the meters over a velocity range that is typical for the size and function of the meters. Meters were then installed at five different locations downstream from a 90-degree short-radius elbow. At each location the meters were tested in two orientations at five different flow rates. The intent of the research is to show that the orientation of a magnetic flow meter affects the meter's ability to produce accurate flow readings when it is installed downstream of a flow disturbance. The results from this research showed a significant shift in measurement accuracy when the meter was in EIP and EOP orientations. All of the meters in the study produced accuracy readings at one point of another that were outside the specified

  9. Satellite splat II: an inelastic collision with a surface-launched projectile and the maximum orbital radius for planetary impact

    NASA Astrophysics Data System (ADS)

    Blanco, Philip R.; Mungan, Carl E.

    2016-07-01

    Starting with conservation of energy and angular momentum, we derive a convenient method for determining the periapsis distance of an orbiting object, by expressing its velocity components in terms of the local circular speed. This relation is used to extend the results of our previous paper, examining the effects of an adhesive inelastic collision between a projectile launched from the surface of a planet (of radius R) and an equal-mass satellite in a circular orbit of radius r s. We show that there is a maximum orbital radius r s ≈ 18.9R beyond which such a collision cannot cause the satellite to impact the planet. The difficulty of bringing down a satellite in a high orbit with a surface-launched projectile provides a useful topic for a discussion of orbital angular momentum and energy. The material is suitable for an undergraduate intermediate mechanics course.

  10. [Validity of modified radiological views to detect screw protrusion at the distal radius. A comparative study with computerized tomography].

    PubMed

    Mora-Pascual, F E; Aguilella-Fernández, L

    2013-01-01

    Volar fixed-angle plates (VFAP) are currently widely used for the treatment of extra-articular distal radius fractures. Using these plates has a high risk of articular and dorsal screw protrusion due to their special configuration. The aim of this study is to assess the validity of the standard X-rays, performed with the help of wedged supports, in order to detect articular and dorsal screw protrusion. A comparison with computed tomography (CT) scan imaging has been made. The outcome of 26 patients with distal radius articular fracture, treated with a VFAP, is reported. Good correlation between modified X-rays and CT scan was observed. A sensitivity of 100% for articular protrusion and 66% for dorsal have been obtained. When detecting screw protrusion at the distal radius, the use of wedged supports to perform special X-rays intraoperatively is an effective tool.

  11. The cloud albedo-cloud droplet effective radius relationship for clean and polluted clouds from RACE and FIRE.ACE

    NASA Astrophysics Data System (ADS)

    Peng, Yiran; Lohmann, Ulrike; Leaitch, Richard; Banic, Catharine; Couture, Mark

    2002-06-01

    Twenty-eight liquid water cloud cases selected from two field studies (the Canadian Radiation, Aerosol and Cloud Experiment (RACE) and the First ISCCP Regional Experiment-Arctic Cloud Experiment (FIRE.ACE)) are analyzed with respect to the first and second indirect aerosol effects and the relationship between cloud droplet effective radius and cloud albedo for clean and polluted clouds. For the same liquid water path the polluted clouds have more and smaller cloud droplets and thus a higher cloud albedo and less drizzle size drops. The effective radius is positively correlated with cloud albedo for polluted clouds caused by the absence of drizzle size drops. Conversely effective radius is negatively correlated with cloud albedo for clean clouds.

  12. Sex- and Maturity-Related Differences in Cortical Bone at the Distal Radius and Midshaft Tibia Evaluated by Quantitative Ultrasonography.

    PubMed

    Baptista, Fátima; Rebocho, Lurdes M; Cardadeiro, Graça; Zymbal, Vera; Rosati, Nicoletta

    2016-09-01

    Boys usually have higher values of bone mineral density measured by dual-energy X-ray absorptiometry than girls, but contradictorily also have a greater incidence of fractures during growth. The purpose of this study was to investigate sex- and maturity-related differences in bone speed of sound (SoS) at the radius and tibia in a sample of 625 healthy children aged 10-14 y and to analyze the contributions of physical activity (PA) to possible dissimilarities. Radial and tibial SoS was evaluated by quantitative ultrasound, maturity was estimated as the years of distance from the peak height velocity age, and PA was assessed by accelerometry. Comparisons between sexes and maturity groups (low: below average [<-2.5 y], high: average or above [≥-2.5 y]) were made by two-sample t-tests with unequal variances. Girls in the high-maturity group had higher SoS at the radius and tibia compared with girls in the low-maturity group (p < 0.001). There were no SoS differences at the radius or tibia between the high- and low-maturity groups in boys. Within high-maturity children, girls had higher SoS than boys at the radius and tibia (p < 0.001). There were no differences at the radius and tibia between girls and boys with low maturity. The results were not modified after controlling for PA. Regardless of PA, the results provide insight into sex- and maturity-related differences in bone SoS at the distal radius and midshaft tibia from maturity less than 2.5 y from the peak height velocity age, with boys having lower SoS. PMID:27181690

  13. Sex- and Maturity-Related Differences in Cortical Bone at the Distal Radius and Midshaft Tibia Evaluated by Quantitative Ultrasonography.

    PubMed

    Baptista, Fátima; Rebocho, Lurdes M; Cardadeiro, Graça; Zymbal, Vera; Rosati, Nicoletta

    2016-09-01

    Boys usually have higher values of bone mineral density measured by dual-energy X-ray absorptiometry than girls, but contradictorily also have a greater incidence of fractures during growth. The purpose of this study was to investigate sex- and maturity-related differences in bone speed of sound (SoS) at the radius and tibia in a sample of 625 healthy children aged 10-14 y and to analyze the contributions of physical activity (PA) to possible dissimilarities. Radial and tibial SoS was evaluated by quantitative ultrasound, maturity was estimated as the years of distance from the peak height velocity age, and PA was assessed by accelerometry. Comparisons between sexes and maturity groups (low: below average [<-2.5 y], high: average or above [≥-2.5 y]) were made by two-sample t-tests with unequal variances. Girls in the high-maturity group had higher SoS at the radius and tibia compared with girls in the low-maturity group (p < 0.001). There were no SoS differences at the radius or tibia between the high- and low-maturity groups in boys. Within high-maturity children, girls had higher SoS than boys at the radius and tibia (p < 0.001). There were no differences at the radius and tibia between girls and boys with low maturity. The results were not modified after controlling for PA. Regardless of PA, the results provide insight into sex- and maturity-related differences in bone SoS at the distal radius and midshaft tibia from maturity less than 2.5 y from the peak height velocity age, with boys having lower SoS.

  14. Fracture of the ulnar styloid process negatively influences the outcome of paediatric fractures of the distal radius.

    PubMed

    Zoetsch, Silvia; Kraus, Tanja; Weinberg, Annelie M; Heidari, Nima; Lindtner, Richard A; Singer, Georg

    2013-02-01

    In paediatric patients with fractures of the distal radius, the consequences of associated ulnar styloid fractures are often underestimated. These may include persisting pain or functional deficits. The aim of the present study was to report the outcome of these fractures using a modified DASH-Score. All children with distal radius fractures treated in a two years period were analysed; only patients with a concomitant fracture of the ulnar styloid were included in the study.In addition, children with a non-union of the styloid at cast removal were asked to complete a postal questionnaire; the data were compared to those in a group of patients with isolated distal radius fractures. Patients reporting problems and those with a modified DASH score over 0.5 were invited for a long-term follow-up clinical and radiological examination. A concomitant fracture of the ulnar styloid was present in 11% of all distal radius fractures. At the time of cast removal 46 patients (89%) showed a delayed union of the ulnar styloid. The modified DASH Score of these patients at an average of 31 months (range: 24-40 months) was significantly worse (3.8; range: 0-24.2) compared to 0.7 (range 0-27.7) in the patients with isolated radius fractures after a mean of 27 months (range: 21-42 months). At follow-up, 7 patients showed a non-union of the ulnar styloid. Fractures of the base of the styloid process were more likely to develop non-union compared to fractures of its tip. The presence of an ulnar styloid fracture negatively influences the outcome of distal radius fractures. Patients with lesions of the ulnar styloid should be followed until union is observed and/or they are asymptomatic. PMID:23547515

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

    SciTech Connect

    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 atoms simultaneously with a π/2 pulse, proposed for a neutron electric dipole moment experiment, is also presented.

  16. Global Radius of Curvature Estimation and Control for the Hobby-Eberly Telescope

    NASA Technical Reports Server (NTRS)

    Rakoczy, John; Hall, Drew; Howard, Ricky; Ly, William; Weir, John; Montgomery, Edward; Brantley, Lott W. (Technical Monitor)

    2002-01-01

    A system, which estimates the global radius of curvature (GroC) and corrects for changes in GroC on a segmented primary mirror has been developed for and verified on McDonald Observatory's Hobby Eberly Telescope (HET). The GroC estimation and control system utilizes HET's primary mirror control (PMC) system and the Segment Alignment Maintenance System (SAMS), an inductive edge sensor system. A special set of boundary conditions is applied to the derivation of the optimal edge match control. The special boundary conditions allow the further derivation of an observer, which enables estimation and control of the Groc mode to within HET's specification. The magnitude of the GroC mode can then be controlled despite the inability of the SAMS edge sensor system, by itself, to observe or control the GroC mode. The observer can be extended to any segmented mirror telescope. It will be shown that the observer improves with accuracy as the number of segments increases. This paper presents the mathematical theory of the observer. Simulation results will demonstrate the inherent accuracy and robustness of the system. Performance verification data from the HET will be presented.

  17. Taylor–Couette turbulence at radius ratio : scaling, flow structures and plumes

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

    Using high-resolution particle image velocimetry we measure velocity profiles, the wind Reynolds number and characteristics of turbulent plumes in Taylor-Couette flow for a radius ratio of 0.5 and Taylor number of up to $6.2\\cdot10^9$. The extracted angular velocity profiles follow a log-law more closely than the azimuthal velocity profiles due to the strong curvature of this $\\eta=0.5$ setup. The scaling of the wind Reynolds number with the Taylor number agrees with the theoretically predicted 3/7-scaling for the classical turbulent regime, which is much more pronounced than for the well-explored $\\eta=0.71$ case, for which the ultimate regime sets in at much lower Ta. By measuring at varying axial positions, roll structures are found for counter-rotation while no clear coherent structures are seen for pure inner cylinder rotation. In addition, turbulent plumes coming from the inner and outer cylinder are investigated. For pure inner cylinder rotation, the plumes in the radial velocity move away from the inner cylinder, while the plumes in the azimuthal velocity mainly move away from the outer cylinder. For counter-rotation, the mean radial flow in the roll structures strongly affects the direction and intensity of the turbulent plumes. Furthermore, it is experimentally confirmed that in regions where plumes are emitted, boundary layer profiles with a logarithmic signature are created.

  18. The Stellar Halos of Massive Elliptical Galaxies. III. Kinematics at Large Radius

    NASA Astrophysics Data System (ADS)

    Raskutti, Sudhir; Greene, Jenny E.; Murphy, Jeremy D.

    2014-05-01

    We present a two-dimensional kinematic analysis out to ~2-5 effective radii (Re ) of 33 massive elliptical galaxies with stellar velocity dispersions σ > 150 km s-1. Our observations were taken using the Mitchell Spectrograph (formerly VIRUS-P), a spectrograph with a large 107 × 107 arcsec2 field of view that allows us to construct robust, spatially resolved kinematic maps of V and σ for each galaxy extending to at least 2 Re . Using these maps, we study the radial dependence of the stellar angular momentum and other kinematic properties. We see the familiar division between slow and fast rotators persisting out to a large radius in our sample. Centrally slow rotating galaxies, which are almost universally characterized by some form of kinematic decoupling or misalignment, remain slowly rotating in their halos. The majority of fast-rotating galaxies show either increases in specific angular momentum outward or no change beyond Re . The generally triaxial nature of the slow rotators suggests that they formed through mergers, consistent with a "two-phase" picture of elliptical galaxy formation. However, we do not observe the sharp transitions in kinematics proposed in the literature as a signpost of moving from central dissipationally formed components to outer accretion-dominated halos.

  19. Application of the N-quantum approximation to the proton radius problem

    NASA Astrophysics Data System (ADS)

    Cowen, Steven

    This thesis is organized into three parts: 1. Introduction and bound state calculations of electronic and muonic hydrogen, 2. Bound states in motion, and 3.Treatment of soft photons. In the first part, we apply the N-Quantum Approximation (NQA) to electronic and muonic hydrogen and search for any new corrections to energy levels that could account for the 0.31 meV discrepancy of the proton radius problem. We derive a bound state equation and compare our numerical solutions and wave functions to those of the Dirac equation. We find NQA Lamb shift diagrams and calculate the associated energy shift contributions. We do not find any new corrections large enough to account for the discrepancy. In part 2, we discuss the effects of motion on bound states using the NQA. We find classical Lorentz contraction of the lowest order NQA wave function. Finally, in part 3, we develop a clothing transformation for interacting fields in order to produce the correct asymptotic limits. We find the clothing eliminates a trilinear interacting Hamiltonian term and produces a quadrilinear soft photon interaction term.

  20. Inductive current startup in large tokamaks with expanding minor radius and rf assist

    SciTech Connect

    Borowski, S.K.

    1984-02-01

    Auxiliary rf heating of electrons before and during the current-rise phase of a large tokamak, such as the Fusion Engineering Device (R = 4.8 m, a = 1.3 m, sigma = 1.6, B/sub T/ = 3.62 T), is examined as a means of reducing both the initiation loop voltage and resistive flux expenditure during startup. Prior to current initiation, 1 to 2 MW of electron cyclotron resonance heating power at approx. 90 GHz is used to create a small volume of high conductivity plasma (T/sub e/ approx. = 100 eV, n/sub e/ approx. = 10/sup 19/ m/sup -3/) near the upper hybrid resonance (UHR) region. This plasma conditioning permits a small radius (a/sub 0/ approx. = 0.2 to 0.4 m) current channel to be established with a relatively low initial loop voltage (less than or equal to 25 V as opposed to approx. 100 V without rf assist). During the subsequent plasma expansion and current ramp phase, a combination of rf heating (up to 5 MW) and current profile control leads to a substantial savings in volt-seconds by: (1) minimizing the resistive flux consumption; and (2) maintaining the internal flux at or near the flat profile limit.

  1. Response of an aggressive periosteal aneurysmal bone cyst (ABC) of the radius to denosumab therapy

    PubMed Central

    2014-01-01

    Aneurysmal bone cyst (ABC), once considered a reactive lesion, has been proven to be a neoplasia characterized by rearrangements of the USP6-gene. Aggressive local growth and recurrences are common and therapeutic options may be limited due to the vicinity of crucial structures. We describe a case of a locally aggressive, multinucleated giant cell-containing lesion of the forearm of a 21-year old woman, treated with denosumab for recurrent, surgically uncontrollable disease. Under the influence of this RANKL inhibitor, the tumor showed a marked reduction of the content of the osteoclastic giant cells and an extensive metaplastic osteoid production leading to the bony containment, mostly located intracortically in the proximal radius. The diagnosis of a periosteal ABC was confirmed by FISH demonstrating USP6 gene rearrangement on the initial biopsy. Function conserving surgery could be performed, enabling reconstruction of the affected bone. Inhibition of RANKL with denosumab may offer therapeutic option for patients not only with giant cell tumors but also with ABCs. PMID:24438319

  2. Structural and elastic determinants of axial transmission ultrasonic velocity in the human radius

    NASA Astrophysics Data System (ADS)

    Raum, Kay; Leguerney, Ingrid; Chandelier, Florent; Talmant, Maryline; Saied, Amena; Laugier, Pascal; Peyrin, Françoise

    2004-10-01

    Accurate clinical interpretation of the sound velocity derived from axial transmission devices requires a detailed understanding of the propa-gation phenomena involved and of the bone factors that have an impact on measurements. In the low-megahertz range, ultrasonic propagation in cortical bone depends on anisotropic elastic tissue properties, porosity, and the spatial dimensions, e.g., cortical thickness. A subset of ten human radius samples from a previous biaxial transmission investigation was inspected using 50-MHz scanning acoustic microscopy (SAM) and synchrotron radiation computed tomography (SR-CT). Low-frequency axial transmission sound speed at 1 and 2 MHz was related to structural properties (cortical thickness C.Th, porosity POR, Haversian cavity density CDH) and tissue parameters (acoustic impedance Z, mineral density MD) on site-matched cross sections. Significant linear multivariate regression models (1 MHz: R=0.84, p<1E-4, 2 MHz: R=0.65, p<1E-4) were found for the combination of C.Th with POR and Z (measured in the external cortical quarter). A modified model accounting for the nonlinear dispersion relation with C.Th was also highly significant (R=0.75, p<1E-4, rmse=49.22 m/s) and explained (after adjustment for dispersion) 55.6% of the variance of the sound velocity by variations of porosity (15.6%) and impedance (40%).

  3. An investigation into the contraction of the hurricane radius of maximum wind

    NASA Astrophysics Data System (ADS)

    Kieu, Chanh Q.

    2012-01-01

    The radius of the maximum tangential wind (RMW) associated with the hurricane primary circulation has been long known to undergo continuous contraction during the hurricane development. In this study, we document some characteristic behaviors of the RMW contraction in a series of ensemble real-time simulations of Hurricane Katrina (2005) and in idealized experiments using the Rotunno and Emanuel (Mon Weather Rev 137:1770-1789, 1987) axisymmetric hurricane model. Of specific interest is that the contraction appears to slow down abruptly at the middle of the hurricane intensification, and the RMW becomes nearly stationary subsequently, despite the rapidly strengthening rotational flows. A kinematic model is then presented to examine such behaviors of the RMW in which necessary conditions for the RMW to stop contracting are examined. Further use of the Emanuel's (J Atmos Sci 43:585-605, 1986) analytical hurricane theory reveals a connection between the hurricane maximum potential intensity and the hurricane eye size, an issue that has not been considered adequately in previous studies.

  4. Neutron skin of (208)Pb, nuclear symmetry energy, and the parity radius experiment.

    PubMed

    Roca-Maza, X; Centelles, M; Viñas, X; Warda, M

    2011-06-24

    A precise determination of the neutron skin Δr(np) of a heavy nucleus sets a basic constraint on the nuclear symmetry energy (Δr(np) is the difference of the neutron and proton rms radii of the nucleus). The parity radius experiment (PREX) may achieve it by electroweak parity-violating electron scattering (PVES) on (208)Pb. We investigate PVES in nuclear mean field approach to allow the accurate extraction of Δr(np) of (208)Pb from the parity-violating asymmetry A(PV) probed in the experiment. We demonstrate a high linear correlation between A(PV) and Δr(np) in successful mean field forces as the best means to constrain the neutron skin of (208)Pb from PREX, without assumptions on the neutron density shape. Continuation of the experiment with higher precision in A(PV) is motivated since the present method can support it to constrain the density slope of the nuclear symmetry energy to new accuracy.

  5. Schwarzschild radius from Monte Carlo calculation of the Wilson loop in supersymmetric matrix quantum mechanics.

    PubMed

    Hanada, Masanori; Miwa, Akitsugu; Nishimura, Jun; Takeuchi, Shingo

    2009-05-01

    In the string-gauge duality it is important to understand how the space-time geometry is encoded in gauge theory observables. We address this issue in the case of the D0-brane system at finite temperature T. Based on the duality, the temporal Wilson loop W in gauge theory is expected to contain the information of the Schwarzschild radius RSch of the dual black hole geometry as log(W)=RSch/(2pialpha'T). This translates to the power-law behavior log(W)=1.89(T/lambda 1/3)-3/5, where lambda is the 't Hooft coupling constant. We calculate the Wilson loop on the gauge theory side in the strongly coupled regime by performing Monte Carlo simulations of supersymmetric matrix quantum mechanics with 16 supercharges. The results reproduce the expected power-law behavior up to a constant shift, which is explainable as alpha' corrections on the gravity side. Our conclusion also demonstrates manifestly the fuzzball picture of black holes. PMID:19518857

  6. Nucleus-nucleus total reaction cross sections, and the nuclear interaction radius

    SciTech Connect

    Abu-Ibrahim, Badawy

    2011-04-15

    We study the nucleus-nucleus total reaction cross sections for stable nuclei, in the energy region from 30A MeV to about 1A GeV, and find them to be in proportion to ({radical}({sigma}{sub pp}{sup tot}Z{sub 1}{sup 2/3}+{sigma}{sub pn}{sup tot}N{sub 1}{sup 2/3})+{radical}({sigma}{sub pp}{sup tot}Z{sub 2}{sup 2/3}+{sigma}{sub pn}{sup tot}N{sub 2}{sup 2/3})) {sup 2} in the mass range 8 to 100. Also, we find a parameter-free relation that enables us to predict a total reaction cross section for any nucleus-nucleus within 10% uncertainty at most, using the experimental value of the total reaction cross section of a given nucleus-nucleus. The power of the relation is demonstrated by several examples. The energy dependence of the nuclear interaction radius is deduced; it is found to be almost constant in the energy range from about 200A MeV to about 1A GeV; in this energy range and for nuclei with N=Z, R{sub I}(A)=(1.14{+-}0.02)A{sup 1/3} fm.

  7. EMERGING TRENDS IN A PERIOD-RADIUS DISTRIBUTION OF CLOSE-IN PLANETS

    SciTech Connect

    Beauge, C.; Nesvorny, D.

    2013-01-20

    We analyze the distribution of extrasolar planets (both confirmed and Kepler candidates) according to their orbital periods P and planetary radii R. Among confirmed planets, we find compelling evidence for a paucity of bodies with 3 R {sub Circled-Plus} < R < 10 R {sub Circled-Plus }, where R {sub Circled-Plus} is Earth's radius and P < 2-3 days. We have christened this region a sub-Jovian Pampas. The same trend is detected in multiplanet Kepler candidates. Although approximately 16 Kepler single-planet candidates inhabit this Pampas, at least 7 are probable false positives (FPs). This last number could be significantly higher if the ratio of FPs is higher than 10%, as suggested by recent studies. In a second part of the paper we analyze the distribution of planets in the (P, R) plane according to stellar metallicities. We find two interesting trends: (1) a lack of small planets (R < 4 R {sub Circled-Plus }) with orbital periods P < 5 days in metal-poor stars and (2) a paucity of sub-Jovian planets (4 R {sub Circled-Plus} < R < 8 R {sub Circled-Plus }) with P < 100 days, also around metal-poor stars. Although all these trends are preliminary, they appear statistically significant and deserve further scrutiny. If confirmed, they could represent important constraints on theories of planetary formation and dynamical evolution.

  8. Free-jet investigation of mechanically suppressed, high radius ratio coannular plug model nozzles

    NASA Technical Reports Server (NTRS)

    Janardan, B. A.; Majjigi, R. K.; Brausch, J. F.; Knott, P. R.

    1985-01-01

    The experimental and analytical acoustic results of a scale-model investigation or unsuppressed and mechanically suppressed high-radius ratio coannular plug nozzles with inverted velocity and temperature profiles are summarized. Nine coannular nozzle configurations along with a reference conical nozzle were evaluated in the Anechoic Free-Jet Facility for a total of 212 acoustic test points. Most of the tests were conducted at variable cycle engine conditions applicable to advanced high speed aircraft. The tested nozzles included coannular plug nozzles with both convergent and convergent-divergent (C-D) terminations in order to evaluate C-D effectiveness in the reduction of shock-cell noise and 20 and 40 shallow-chute mechanical suppressors in the outer stream in order to evaluate their effectiveness in the reduction of jet noise. In addition to the acoustic tests, mean and turbulent velocity measurements were made on selected plumes of the 20 shallow-chute configuration using a laser velocimeter. At a mixed jet velocity of 700 m/sec, the 20 shallow-chute suppressor configuration yielded peak aft quadrant suppression of 11.5 and 9 PNdB and forward quadrant suppression of 7 and 6 PNdB relative to a baseline conical nozzles during static and simulated flight, respectively. The C-D terminations were observed to reduce shock-cell noise. An engineering spectral prediction method was formulated for mechanically suppressed coannular plug nozzles.

  9. Study of Cloud Droplet Radius and Cloud Optical Thickness in "Warm" Clouds Using Satellite Data

    NASA Astrophysics Data System (ADS)

    Grigoras, Cristinel; Stefan, Sabina

    2014-05-01

    The present study is focused on the analysis of the cloud microphysical properties using two very important parameters which characterize the liquid water clouds: the cloud droplet radius and the cloud optical thickness. It is known that the knowledge of the variations of these parameters can provide valuable information on most microphysical processes in clouds. Therefore, the correlation between these parameters has been carefully considered. Satellite data from the MODIS 06 system has been analyzed first, for four years time span (2008-2011) and then for the summer's months of the years 2010 and 2011. The data collected from three stations was used to analyze the dependence between the two parameters: a continental station (in Magurele, Ilfov, lat 44.34, lon 26.03), a coastal station (Eforie Nord, Constanta, lat 44.07,lon 28.63) and a maritime station (Gloria, lat 44.6, lon 29.36), all from Romania. The relationship between the cloud droplet radii and the cloud optical thicknesses obtained processing satellite data for the four years between 2008 and 2011 shows a good correlation (correlation coefficient 0.54). The ensuing relationship between the two parameters could be used for cloud microphysics studies. The analysis of dependence between cloud droplet radii and cloud optical thickness from satellite data during summer confirms the presence of their positive correlation. But contrary of the expectations, the analysis shows very small differences between the results found out for the three different locations.

  10. Maximum drop radius and critical Weber number for splashing in the dynamical Leidenfrost regime

    NASA Astrophysics Data System (ADS)

    Riboux, Guillaume; Gordillo, Jose Manuel

    2015-11-01

    At room temperature, when a drop impacts against a smooth solid surface at a velocity above the so called critical velocity for splashing, the drop loses its integrity and fragments into tiny droplets violently ejected radially outwards. Below this critical velocity, the drop simply spreads over the substrate. Splashing is also reported to occur for solid substrate temperatures above the Leidenfrost temperature, T, for which a vapor layer prevents the drop from touching the substrate. In this case, the splashing morphology largely differs from the one reported at room temperature because, thanks to the presence of the gas layer, the shear stresses on the liquid do not decelerate the ejected lamella. Our purpose here is to predict, for wall temperatures above T, the dependence of the critical impact velocity on the temperature of the substrate as well as the maximum spreading radius for impacting velocities below the critical velocity for splashing. This is done making use of boundary integral simulations, where the velocity and the height of the liquid layer at the root of the ejected lamella are calculated numerically. This information constitutes the initial conditions for the one dimensional mass and momentum equations governing the dynamics of the toroidal rim limiting the edge of the lamella.

  11. Minimally invasive plate osteosythesis of fractures of the radius and ulna in a primate.

    PubMed

    Tong, K; Guiot, L P

    2013-01-01

    A 25-year-old female mandrill (Mandrillus sphinx - a primate and part of the Old World monkey group) was presented with a mildly comminuted, diaphyseal, radial fracture associated with a transverse ulnar fracture. Minimally invasive plate osteosynthesis techniques were used to achieve fixation of both the radial and the ulnar fractures. First, closed fracture reduction was achieved with a distraction frame consisting of a motorized circular external skeletal fixator. Next, dual percutaneous radio-ulnar plating was performed using a 2.7 limited-contact dynamic compression plate on the cranial aspect of the radius and two stacked 2.0/2.7 veterinary cut-to-length plates on the lateral aspect of the ulna. Uncomplicated recovery was observed with a complete return to normal activity three months postoperatively. Fracture healing was documented at four weeks, clinical union at 14 weeks, and callus remodelling at 24 weeks postoperatively. This report demonstrates the feasibility of minimally invasive plate osteosynthesis in a primate and shows the adaptability of this technique across mammalian species. PMID:23708981

  12. The Roles of Cloud Drop Effective Radius and LWP in Determining Rain Properties in Marine Stratocumulus

    SciTech Connect

    Rosenfeld, Daniel; Wang, Hailong; Rasch, Philip J.

    2012-07-04

    Numerical simulations described in previous studies showed that adding cloud condensation nuclei to marine stratocumulus can prevent their breakup from closed into open cells. Additional analyses of the same simulations show that the suppression of rain is well described in terms of cloud drop effective radius (re). Rain is initiated when re near cloud top is around 12-14 um. Cloud water starts to get depleted when column-maximum rain intensity (Rmax) exceeds 0.1 mm h-1. This happens when cloud-top re reaches 14 um. Rmax is mostly less than 0.1 mm h-1 at re<14 um, regardless of the cloud water path, but increases rapidly when re exceeds 14 um. This is in agreement with recent aircraft observations and theoretical observations in convective clouds so that the mechanism is not limited to describing marine stratocumulus. These results support the hypothesis that the onset of significant precipitation is determined by the number of nucleated cloud drops and the height (H) above cloud base within the cloud that is required for cloud drops to reach re of 14 um. In turn, this can explain the conditions for initiation of significant drizzle and opening of closed cells providing the basis for a simple parameterization for GCMs that unifies the representation of both precipitating and non-precipitating clouds as well as the transition between them. Furthermore, satellite global observations of cloud depth (from base to top), and cloud top re can be used to derive and validate this parameterization.

  13. Relationship between Patient Satisfaction and Objective Functional Outcome after Surgical Treatment for Distal Radius Fractures

    PubMed Central

    Chung, Kevin C.; Haas, Ann

    2009-01-01

    Study Design Prospective Cohort. Introduction Patient satisfaction is increasingly used as a metric of health care outcomes. The relationship between patient satisfaction and functional outcomes metrics is understudied. Purpose To determine the minimum recovery needed in grip strength, key pinch strength, and arc of motion needed for patient satisfaction after treatment of distal radius fracture (DRF) with volar locking plating system placement. Methods A prospective cohort of 125 DRF patients was evaluated 3 months after surgery for grip strength, key pinch strength, wrist arc of motion, and satisfaction with hand strength and wrist arc of motion. Receiver operating characteristic (ROC) curves were constructed using patient satisfaction items as the “gold standard” and each functional measure of outcome as a predictor. Results We found that the optimal cut-points to distinguish satisfaction from dissatisfaction occurred when patients had recovered 65% of their grip strength, 87% of their key grip strength, and 95% of the wrist arc of motion, as measured as percents of their uninjured wrists. Conclusions A much greater wrist range of motion must be recovered for patients to be satisfied than what is needed to perform activities of daily living. Level of Evidence Diagnosis Level 2. PMID:19560317

  14. Strongly magnetized cold electron degenerate gas: Mass-radius relation of the collapsed star

    NASA Astrophysics Data System (ADS)

    Das, Upasana; Mukhopadhyay, Banibrata

    2012-07-01

    We consider a relativistic, degenerate electron gas at zero-temperature under the influence of a strong, uniform, static magnetic field, neglecting any form of interactions. Since the density of states for the electrons changes due to the presence of the magnetic field (which gives rise to Landau quantization), the corresponding equation of state also gets modified. In order to investigate the effect of very strong magnetic field, we focus only on systems in which a maximum of either one, two or three Landau level(s) is/are occupied. This is important since, if a very large number of Landau levels are filled, it implies a very low magnetic field strength which yields back Chandrasekhar's celebrated non-magnetic results. The maximum number of Landau levels occupied is fixed by the correct choice of two parameters, namely the magnetic field strength and the maximum Fermi energy of the system. We study the equations of state of these one-level, two-level and three-level systems and compare them by taking three different maximum Fermi energies. We also find the effect of the strong magnetic field on the mass-radius relation of the underlying star composed of the gas stated above. We obtain an interesting theoretical result that, it is possible to have an electron degenerate static star with a mass significantly greater than the Chandrasekhar limit, provided it has an appropriate magnetic field strength and central density.

  15. Arthroscopic study of injuries in articular fractures of distal radius extremity

    PubMed Central

    Araf, Marcelo; Mattar, Rames

    2014-01-01

    OBJECTIVE: To analyze the incidence of wrist ligament and cartilage associated fractures of the distal radius, through arthroscopy, correlating with AO/ASIF classification. METHODS: Thirty patients aged between 20 and 50 years old, with closed fracture from groups B and C according to AO/ASIF classification were selected. All of them were submitted to wrist arthroscopy to address intra-articular injuries and reduction and osteosynthesis of the fracture. RESULTS: A high incidence of intra-articular injuries was noticed, and 76.6% of them presented injury of the triangular fibrocartilage complex, 36.6% of the intrinsic scapholunate ligament, 6.6% of the intrinsic triquetrolunate ligament, and 33% articular cartilage injury larger than three millimeters. Patients with fractures from type C according to AO/ASIF classification presented a higher incidence of ligament injuries. CONCLUSION: There is no relationship between the presence of chondral injury and the AO/ASIF classification of the fractures in the cases reported in this study. Level of Evidence III, Non Randomized Controlled Trial. PMID:25061421

  16. GALAXY CLUSTERS AT THE EDGE: TEMPERATURE, ENTROPY, AND GAS DYNAMICS NEAR THE VIRIAL RADIUS

    SciTech Connect

    Burns, Jack O.; Skillman, Samuel W.; O'Shea, Brian W.

    2010-10-01

    Recently, Suzaku has produced temperature and entropy profiles, along with profiles of gas density, gas fraction, and mass, for multiple galaxy clusters out to approximately the virial radius. In this paper, we compare these novel X-ray observations with results from N-body + hydrodynamic adaptive mesh refinement cosmological simulations using the Enzo code. There is excellent agreement in the temperature, density, and entropy profiles between a sample of 24 mostly substructure-free massive clusters in the simulated volume and the observed clusters. This supports our previous contention that clusters have 'universal' outer temperature profiles. Furthermore, it appears that the simplest adiabatic gas physics used in these Enzo simulations is adequate to model the outer regions of these clusters without other mechanisms (e.g., non-gravitational heating, cooling, magnetic fields, or cosmic rays). However, the outskirts of these clusters are not in hydrostatic equilibrium. There is significant bulk flow and turbulence in the outer intracluster medium created by accretion from filaments. Thus, the gas is not fully supported by thermal pressure. The implications for mass estimation from X-ray data are discussed.

  17. Retrievals of cloud optical depth and effective radius from Thin-Cloud Rotating Shadowband Radiometer measurements

    SciTech Connect

    Yin B.; Vogelmann A.; Min Q.; Duan M.; Bartholomew M. J.; Turner D. D.

    2011-12-13

    A Thin-Cloud Rotating Shadowband Radiometer (TCRSR) was developed and deployed in a field test at the Atmospheric Radiation Measurement Climate Research Facility's Southern Great Plains site. The TCRSR measures the forward-scattering lobe of the direct solar beam (i.e., the solar aureole) through an optically thin cloud (optical depth < 8). We applied the retrieval algorithm of Min and Duan (2005) to the TCRSR measurements of the solar aureole to derive simultaneously the cloud optical depth (COD) and cloud drop effective radius (DER), subsequently inferring the cloud liquid-water path (LWP). After careful calibration and preprocessing, our results indicate that the TCRSR is able to retrieve simultaneously these three properties for optically thin water clouds. Colocated instruments, such as the MultiFilter Rotating Shadowband Radiometer (MFRSR), atmospheric emitted radiance interferometer (AERI), and Microwave Radiometer (MWR), are used to evaluate our retrieval results. The relative difference between retrieved CODs from the TCRSR and those from the MFRSR is less than 5%. The distribution of retrieved LWPs from the TCRSR is similar to those from the MWR and AERI. The differences between the TCRSR-based retrieved DERs and those from the AERI are apparent in some time periods, and the uncertainties of the DER retrievals are discussed in detail in this article.

  18. Distal radius fractures-Design of locking mechanism in plate system and recent surgical procedures.

    PubMed

    Inagaki, Katsunori; Kawasaki, Keikichi

    2016-05-01

    Recently, many studies have emphasized the importance of the comprehension of detailed functional anatomy of the distal forearm and wrist joint, and their biomechanics. A significant contribution which yields good functional outcomes of surgical treatment was the development of the locking plate technology; this technology has facilitated the improvement of the surgical technique for the fixation of fractures. This article reviews the locking mechanism and design of the fixation screws and plate, and the details of the surgical technique including the double-tired subchondral support procedure as it is applied to common fractures. Arthroscopic-assisted surgical procedures can be used to reduce the intra-articular fracture fragments after realignment of the distal radius with the locking plate. This technique is also useful at the time of fixation to assess soft tissue injury. The combination of arthroscopic-assisted reduction and locking plate fixation is now indicated for AO type C2 and C3 intra-articular comminuted fractures. PMID:27006135

  19. Calibrating the Mass-Radius-Temperature Relation in the Low-Mass Regime

    NASA Astrophysics Data System (ADS)

    Gomez Maqueo Chew, Yilen; Hebb, Leslie; Faedi, Francesca; Keating, Katie M.; Stassun, Keivan; Pollacco, Don; Rodler, Florian; Collier Cameron, Andrew

    2013-08-01

    We request a total of 9 nights with FLAMINGOS at the KPNO 2.1m to obtain the J and Ks-band light curves of low-mass M dwarfs in eclipsing binaries with F/G/K primaries. This is part of a larger effort to constrain the mass-radius-temperature relation as a function of activity and metallicity at the bottom of the main sequence with unprecedented large number statistics. With these observations, we will determine the temperature of the M dwarfs by comparing the secondary eclipse depth with the primary temperature as measured from spectral synthesis. The measurement of the secondary eclipse is only possible in the near- infrared, where the M dwarfs are brighter. To achieve precise measurements, the observations require a temporal coverage of the secondary minimum, and part of the out-of-eclipse phases. The comprehensive modeling of the binaries, including radial velocity and multi-band light curves, will allow us to fully determine their fundamental properties, including masses, radii and temperatures.

  20. Radius of influence for a cosmic-ray soil moisture probe : theory and Monte Carlo simulations.

    SciTech Connect

    Desilets, Darin

    2011-02-01

    The lateral footprint of a cosmic-ray soil moisture probe was determined using diffusion theory and neutron transport simulations. The footprint is radial and can be described by a single parameter, an e-folding length that is closely related to the slowing down length in air. In our work the slowing down length is defined as the crow-flight distance traveled by a neutron from nuclear emission as a fast neutron to detection at a lower energy threshold defined by the detector. Here the footprint is defined as the area encompassed by two e-fold distances, i.e. the area from which 86% of the recorded neutrons originate. The slowing down length is approximately 150 m at sea level for neutrons detected over a wide range of energies - from 10{sup 0} to 10{sup 5} eV. Both theory and simulations indicate that the slowing down length is inversely proportional to air density and linearly proportional to the height of the sensor above the ground for heights up to 100 m. Simulations suggest that the radius of influence for neutrons >1 eV is only slightly influenced by soil moisture content, and depends weakly on the energy sensitivity of the neutron detector. Good agreement between the theoretical slowing down length in air and the simulated slowing down length near the air/ground interface support the conclusion that the footprint is determined mainly by the neutron scattering properties of air.