394 research outputs found
Development and Evaluation of a Multi-frequency Bioelectrical Impedance Analysis Analyzer for Estimating Acupoint Composition
AbstractThe purpose of this study was to suggest a new method of estimating acupoint compositions by using a multi-frequency bioelectrical impedance analysis (MF-BIA) method at 5 kHz, 50 kHz and 200 kHz within 2 cm of acupoints divided into local segments. To verify the system developed, we confirmed the stable occurrence of a constant current at every frequency, regardless of the impedance connected to the electrodes. Moreover, we found left and right distal bicep brachii aponeurosis to be identical by using ultrasound imaging, and we analyzed the repeatability of the findings by making 10 consecutive sets of measurements (p > 0.05). To evaluate the practical use of the acupoint composition, we used the MF-BIA analyzer to measure the left and right LU3, LU4, and LU9 at the lung meridian. We confirmed that the potentials generated were equal to the changes in the cell membrane function, which were caused by the applied frequency (p < 0.01). We also verified that the MF-BIA analyzer measurements corresponded to the acupoint components by comparing the left and right potentials generated (p > 0.05). Hence, we conclude that the MF-BIA analyzer can be used to estimate the acupoint composition based on the acupoint state
Versatile double hydrophilic block copolymer: dual role as synthetic nanoreactor and ionic and electronic conduction layer for ruthenium oxide nanoparticle supercapacitors
The facile synthetic approach to ruthenium oxide nanoparticles using double hydrophilic block copolymers (DHBCs) and their application toward the supercapacitor are presented. Nanostructured hydrous ruthenium oxide (RuO2) nanoparticles are synthesized using a double hydrophilic block copolymer of poly(ethylene oxide)-block-poly(acrylic acid) (PEO-b-PAA) as a template, forming a micelle upon addition of the ruthenium precursor, which then transformed into RuO2 nanoparticles of controlled dimension with reducing agents. The synthesized hydrous RuO2 center dot xH(2)O nanoparticles are very stable for several months without any noticeable aggregates. Furthermore, we have demonstrated their utility in application as supercapacitors. Through annealing at 400 degrees C, we found that the crystallinity of RuO2 nanoparticles increases considerably with a simultaneous transformation of the surrounding double hydrophilic block copolymer into ionic and electronic conducting buffer layers atop RuO2 nanoparticles, which contribute to the significant enhancement of the overall specific capacitance from 106 to 962 F g(-1) at 10 mV s(-1). The RuO2 nanoparticles annealed at 400 degrees C also exhibit a superior retention of capacitance over 1000 cycles at very high charge-discharge rates at 20 A g(-1). We envision that the double hydrophilic block copolymer will provide a facile and general tool in creating functional nanostructures with controlled dimensions that are useful for various applications.close9
Hybrid star HD 81817 accompanied by brown dwarf or substellar companion
HD 81817 is known as a hybrid star. Hybrid stars have both cool stellar wind
properties and Ultraviolet (UV) or even X-ray emission features of highly
ionized atoms in their spectra. A white dwarf companion has been suggested as
the source of UV or X-ray features. HD 81817 has been observed since 2004 as a
part of a radial velocity (RV) survey program to search for exoplanets around K
giant stars using the Bohyunsan Observatory Echelle Spectrograph at the 1.8 m
telescope of Bohyunsan Optical Astronomy Observatory in Korea. We obtained 85
RV measurements between 2004 and 2019 for HD 81817 and found two periodic RV
variations. The amplitudes of RV variations are around 200 m s^-1, which are
significantly lower than that expected from a closely orbiting white dwarf
companion. Photometric data and relevant spectral lines were also analyzed to
help determine the origin of the periodic RV variations. We conclude that
627.4-day RV variations are caused by intrinsic stellar activities such as
long-term pulsations or rotational modulations of surface activities based on
H{\alpha} equivalent width (EW) variations of a similar period. On the other
hand, 1047.1-day periodic RV variations are likely to be caused by a brown
dwarf or substellar companion, which is corroborated by a recent GAIA proper
motion anomaly for HD 81817. The Keplerian fit yields a minimum mass of 27.1
M_Jup, a semimajor axis of 3.3 AU, and an eccentricity of 0.17 for the stellar
mass of 4.3 M_sun for HD 81817. The inferred mass puts HD 81817 b in the brown
dwarf desert
A Planetary Companion to the Intermediate-Mass Giant HD 100655
A precise radial velocity survey conducted by a Korean-Japanese planet search
program revealed a planetary companion around the intermediate-mass clump giant
HD 100655. The radial velocity of the star exhibits a periodic Keplerian
variation with a period, semi-amplitude and eccentricity of 157.57 d, 35.2 m
s^-1 and 0.085, respectively. Adopting an estimated stellar mass of 2.4 M_Sun,
we confirmed the presence of a planetary companion with a semi-major axis of
0.76 AU and a minimum mass of 1.7 M_Jup. The planet is the lowest-mass planet
yet discovered around clump giants with masses greater than 1.9 M_Sun.Comment: 17 pages, 8 figures, accepted for publication in PAS
Korean-Japanese Planet Search Program: Substellar Companions around Intermediate-Mass Giants
A Korean-Japanese planet search program has been carried out using the 1.8m
telescope at Bohyunsan Optical Astronomy Observatory (BOAO) in Korea, and the
1.88m telescope at Okayama Astrophysical Observatory (OAO) in Japan to search
for planets around intermediate-mass giant stars. The program aims to show the
properties of planetary systems around such stars by precise Doppler survey of
about 190 G or K type giants together with collaborative surveys of the
East-Asian Planet Search Network. So far, we detected two substellar companions
around massive intermediate-mass giants in the Korean-Japanese planet search
program. One is a brown dwarf-mass companion with 37.6
orbiting a giant HD 119445 with 3.9 , which is the most massive
brown dwarf companion among those found around intermediate-mass giants. The
other is a planetary companion with 1.8 orbiting a giant star
with 2.4 , which is the lowest-mass planetary companion among those
detected around giant stars with 1.9 . Plotting these systems on
companion mass vs. stellar mass diagram, there seem to exist two unpopulated
regions of substellar companions around giants with 1.5--3 and
planetary companions orbiting giants with 2.4--4 . The existence of
these possible unpopulated regions supports a current characteristic view that
more massive substellar companions tend to exist around more massive stars.Comment: 8 pages, 3 figures, Part of PlanetsbeyondMS/2010 proceedings
http://arxiv.org/html/1011.660
Effect of Wavelength and Intensity of Light on a-InGaZnO TFTs under Negative Bias Illumination Stress
We investigated degradation mechanism of a-IGZO TFTs under NBIS with different wavelengths. and intensities IL of light. Negative gate bias was applied for 4000 s while drain and source were grounded, and illuminations with lambda = 450, 530, or 700 nm were applied. Illumination with photon energy exceeding similar to 2.3 eV (530 nm) induced noticeable change in threshold voltage shift Delta V-th, which can be interpreted in terms of ionization of oxygen vacancies V-O. In addition, I-L of blue illumination (450 nm) was varied from 6 to 200 lux and saturation in Delta V-th was observed after exceeding a certain I-L. We suggest that the saturation occurs because V-O-ionization rate is saturated by outward relaxation of metal atoms in the a-IGZO film. (C) The Author(s) 2016. Published by ECS.1174Ysciescopu
High-resolution near-IR Spectral mapping with H and [Fe II] lines of Multiple Outflows around LkH 234
We present a high-resolution, near-IR spectroscopic study of multiple
outflows in the LkH 234 star formation region using the Immersion
GRating INfrared Spectrometer (IGRINS). Spectral mapping over the blueshifted
emission of HH 167 allowed us to distinguish at least three separate, spatially
overlapped, outflows in H and [Fe II] emission. We show that the H
emission represents not a single jet, but complex multiple outflows driven by
three known embedded sources: MM1, VLA 2, and VLA 3. There is a redshifted
H outflow at a low velocity, \VLSR 50 {\kms}, with respect to
the systemic velocity of \VLSR 11.5 {\kms}, that coincides with the
HO masers seen in earlier radio observations two arcseconds southwest of
VLA 2. We found that the previously detected [Fe II] jet with \VLSR
100 {\kms} driven by VLA 3B is also detected in H emission, and confirm
that this jet has a position angle about 240. Spectra of the
redshifted knots at 14\arcsec65\arcsec northeast of LkH 234 are
presented for the first time. These spectra also provide clues to the existence
of multiple outflows. We detected high-velocity (50120 {\kms}) H gas
in the multiple outflows around LkH 234. Since these gases move at
speeds well over the dissociation velocity ( 40 {\kms}), the emission must
originate from the jet itself rather than H gas in the ambient medium.
Also, position-velocity diagrams and excitation diagram indicate that emission
from knot C in HH 167 come from two different phenomena, shocks and
photodissociation.Comment: 32 pages, 12 figures, 2 tables, Accepted for publication in the
Astrophysical Journa
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