286 research outputs found
Formation Mechanism of 100 nm-Scale Periodic-Structures in Silicon Using Magnetic-Field-Assisted Anodization
KNEE AND ANKLE JOINT KINEMATICS IN KENDO MOVEMENT AND THE REPEATABILITY
Kendo, a Japanese martial art of sword fighting, comprises strike and thrust motion against a specific target of a part of an opponent’s body. Among kendo athletes, chronic Achilles tendon (AT) injuries are frequently observed only on the left side probably because a main power source lies in the left side of the lower body for the repetitive forward-back bounding steps in the strike motion. It has been reported that the AT injury may be linked to abnormal joint biomechanics among runners. In order to make better clinical decision on the AT injury treatment in kendo athletes, therefore, we should focus on joint biomechanics of the left side of the lower extremity in kendo movement. The purpose of the study was to demonstrate the joint kinematics of knee and ankle in the kendo movement and quantify the repeatability
A new design of nanocrystalline silicon optical devices based on 3-dimensional photonic crystal structures
We propose a new design of nanocrystalline silicon optical devices which are based on control of electromagnetic fields, electronic states, as well as the phonon dispersion of size-controlled silicon quantum dots
RELATIONSHIP BETWEEN MUSCULAR OUTPUTS AND THE HORIZONTAL PERTURBATION IN THE EARLY PHASE OF BENCH PRESS MOVEMENT UNDER STABLE AND UNSTABLE CONDITIONS
We demonstrated the relationship between the change rates of muscular outputs and horizontal perturbation under stable and unstable conditions in dynamic bench press movement. Twenty-seven male collegiate athletes attended the study. We used a tri-axis accelerometer attached to the barbell shaft to obtain the acceleration data in the bench press and computed peak force output, rate of force development (RFD), and horizontal acceleration trajectory length for 0.2 seconds after the initiation. Significant reduction was found in the peak force output and RFD under stable and unstable conditions, but not in the horizontal acceleration trajectory length. Significant correlation was found between the change rate of RFD and the horizontal acceleration trajectory length under stable and unstable conditions (r=0.55,
CuPc Adsorption on Au(110)-(1 × 2): From a Monomer to a Periodic Chain
Using scanning tunneling microscopy (STM), we study the adsorption of copper-phthalocyanine (CuPc) on the anisotropic Au(110)-(1 × 2) surface as a function of coverage. For the initial adsorption at room temperature, we observe CuPc monomers as well as a molecular chain that forms along the step edge. By STM manipulation, we reveal that the CuPc adsorption is accompanied by surface reconstruction from the initial adsorption stage; the periodicity beneath the monomer and the chain changes locally from (1 × 2) to (1 × 1) and (1 × 3), respectively. This finding highlights that the Au atom mobility of the surface plays an essential role in CuPc adsorption. At higher coverage, we observe the development of CuPc chains along the [110] direction on the terrace with periodicities of (7 × 5) and (5 × 5), and compare the obtained results with those from the previous studies by diffraction methods
Higher order glass-transition singularities in colloidal systems with attractive interactions
The transition from a liquid to a glass in colloidal suspensions of particles
interacting through a hard core plus an attractive square-well potential is
studied within the mode-coupling-theory framework. When the width of the
attractive potential is much shorter than the hard-core diameter, a reentrant
behavior of the liquid-glass line, and a glass-glass-transition line are found
in the temperature-density plane of the model. For small well-width values, the
glass-glass-transition line terminates in a third order bifurcation point, i.e.
in a A_3 (cusp) singularity. On increasing the square-well width, the
glass-glass line disappears, giving rise to a fourth order A_4 (swallow-tail)
singularity at a critical well width. Close to the A_3 and A_4 singularities
the decay of the density correlators shows stretching of huge dynamical
windows, in particular logarithmic time dependence.Comment: 19 pages, 12 figures, Phys. Rev. E, in prin
Exploring the inner region of Type 1 AGNs with the Keck interferometer
The exploration of extragalactic objects with long-baseline interferometers
in the near-infrared has been very limited. Here we report successful
observations with the Keck interferometer at K-band (2.2 um) for four Type 1
AGNs, namely NGC4151, Mrk231, NGC4051, and the QSO IRAS13349+2438 at z=0.108.
For the latter three objects, these are the first long-baseline interferometric
measurements in the infrared. We detect high visibilities (V^2 ~ 0.8-0.9) for
all the four objects, including NGC4151 for which we confirm the high V^2 level
measured by Swain et al.(2003). We marginally detect a decrease of V^2 with
increasing baseline lengths for NGC4151, although over a very limited range,
where the decrease and absolute V^2 are well fitted with a ring model of radius
0.45+/-0.04 mas (0.039+/-0.003 pc). Strikingly, this matches independent radius
measurements from optical--infrared reverberations that are thought to be
probing the dust sublimation radius. We also show that the effective radius of
the other objects, obtained from the same ring model, is either roughly equal
to or slightly larger than the reverberation radius as a function of AGN
luminosity. This suggests that we are indeed partially resolving the dust
sublimation region. The ratio of the effective ring radius to the reverberation
radius might also give us an approximate probe for the radial structure of the
inner accreting material in each object. This should be scrutinized with
further observations.Comment: accepted for publication in A&A Letter
Reverberation Measurements of the Inner Radius of the Dust Torus in Nearby Seyfert 1 Galaxies
The most intense monitoring observations yet made in the optical (UBV) and
near-infrared (JHK) wave bands were carried out for nearby Seyfert1 galaxies of
NGC 5548, NGC 4051, NGC 3227, and NGC 7469. Over three years of observations
with MAGNUM telescope since early 2001, clear time-delayed response of the
K-band flux variations to the V-band flux variations was detected for all of
these galaxies. Their H-K color temperature was estimated to be 1500-1800 K
from the observed flux variation gradients, which supports a view that the bulk
of the K flux should originate in the thermal radiation of hot dust that
surrounds the central engine. Cross-correlation analysis was performed to
quantify the lag time corresponding to the light-travel distance of the hot
dust region from the central engine. The measured lag time is 47-53 days for
NGC 5548, 11-18 days for NGC 4051, about 20 days for NGC 3227, and 65-87 days
for NGC 7469. We found that the lag time is tightly correlated with the optical
luminosity as expected from dust reverberation (),
while only weakly with the central virial mass, which suggests that an inner
radius of the dust torus around the active nucleus has a one-to-one
correspondence to central luminosity. In the lag time versus central luminosity
diagram, the K-band lag times place an upper boundary on the similar lag times
of broad-emission lines in the literature. This not only supports the unified
scheme of AGNs, but also implies a physical transition from the BLR out to the
dust torus that encircles the BLR. Furthermore, our V-band flux variations of
NGC 5548 on timescales of up to 10 days are found to correlate with X-ray
variations and delay behind them by one or two days, indicating the thermal
reprocessing of X-ray emission by the central accretion flow.Comment: ApJ, March 2006, v639 issue, 24 pages, 33 figures, 10 table
Reverberation Mapping Results for Five Seyfert 1 Galaxies
We present the results from a detailed analysis of photometric and
spectrophotometric data on five Seyfert 1 galaxies observed as a part of a
recent reverberation mapping program. The data were collected at several
observatories over a 140-day span beginning in 2010 August and ending in 2011
January. We obtained high sampling-rate light curves for Mrk 335, Mrk 1501,
3C120, Mrk 6, and PG2130+099, from which we have measured the time lag between
variations in the 5100 Angstrom continuum and the H-beta broad emission line.
We then used these measurements to calculate the mass of the supermassive black
hole at the center of each of these galaxies. Our new measurements
substantially improve previous measurements of MBH and the size of the broad
line-emitting region for four sources and add a measurement for one new object.
Our new measurements are consistent with photoionization physics regulating the
location of the broad line region in active galactic nuclei.Comment: 45 pages, 5 figures. Accepted for publication in ApJ. For a brief
video explaining the key results of this paper, see
http://www.youtube.com/user/OSUAstronom
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