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991.
Objectives
The present study was performed to examine which factors among self-rated scales, perceptual evaluations, and acoustic parameters, calculated from sustained vowels, are reliable indicators of physical and mental fatigues.Methods
A total of 73 volunteers (male:female, 52:21), aged 19–24 years, were enrolled in this study. We defined the high- and low-fatigue groups using the Chalder Fatigue Scale score. For assessment of self-rated symptoms, each subject was asked to complete Voice Handicap Index (VHI) and Voice Rating Scale (VRS). For perceptual evaluations, three clinicians assessed each subject’s vocal quality on the Grade, Roughness, Breathiness, Asthenia, Strain Scale. For acoustic analysis, each subject was asked to produce sustained vowels /a/, /e/, /i/, /o/, and /u/ for 3 seconds. Then, the habitual fundamental frequency (F0), jitter, shimmer, F0 tremor, mean F0, standard deviation of F0, maximum F0, minimum F0, normalized noise energy, harmonic-to-noise ratio (HNR), signal-to-noise ratio (SNR), amplitude tremor, and ratio within 2–4 kHz were calculated using Dr. Speech software.Results
In men, VHI, VRS, F0 tremor, shimmer, HNR, SNR, and amplitude tremor were related to mental fatigue. In women, only VHI was related to physical fatigue, and none of the acoustic parameters was related to the fatigue score. Perceptual evaluations were not related to fatigue in men or women.Conclusions
These findings suggest that self-rated symptoms and acoustic parameters related to voice quality are indicative of mental fatigue, and these features are prominent in men. 相似文献992.
Hyun-Seo Park 《Thermophysics and Aeromechanics》2011,18(2):313-321
The paper presents the investigation of plasma melting of the mixed bottom and fly incineration ash at various mixing ratios
of the components. Chemical compound of the bottom and fly ash as well as the slag after its melting was analyzed by different
methods, and the content of toxic components in them was determined. It is demonstrated that the direct disposal of the fly
and bottom incineration ash may cause dioxin and heavy metal contamination of the environment. The influence of melted ash
basicity on the resulting slag compound was studied. The mass balance of the melting process was defined. The tests were performed
to determine the heavy-metals leaching from the ash and slag. It is also shown that the slag after plasma melting is dioxin-free
and environmentally friendly. 相似文献
993.
I.-H. Bae H. S. Moon S. Zaske C. Becher S. K. Kim S.-N. Park D.-H. Lee 《Applied physics. B, Lasers and optics》2011,103(2):311-319
We present a 532 nm-pumped singly-resonant cw optical parametric oscillator based on MgO-doped PPLN with a minimum threshold
pump power of 0.3 W. The OPO with a two-mirror standing-wave cavity is optimized by using a tunable diode laser on the path
of the resonant signal beam. The maximum output power is 200 mW at an idler wavelength near 1330 nm at a pump power of 2 W.
We report the degradation of the output power and beam characteristics at high pump power indicating a strong thermal lensing
in the crystal. The continuous tuning range of the OPO is measured to be 800 MHz which is close to 90% of the free spectral
range of the OPO cavity. 相似文献
994.
J.-H. Lee B.-H. Jun S.-D. Park B.J. Park S.C. Han S.H. Lee C.-J. Kim 《Physica C: Superconductivity and its Applications》2011,471(21-22):863-866
To suppress the samarium diffusion from a SmBa2Cu3O7?y (Sm123) seed into an YBa2Cu3O7?y (Y123) compact during a top seeded melt growth (TSMG) process, Y211 buffer disks of various thicknesses (t) were inserted at the seed/compact interface. The effectiveness of the Y211 buffer insert on the suppression of samarium diffusion was estimated from the susceptibility curve and composition analysis for the three top surface regions (region just below the seed/buffer, intermediate region between the buffer and compact edge and compact edge). The difference in the superconducting temperature (Tc) and the superconducting transition width (ΔT) in the three regions was large, when no buffer or thin buffers (t is smaller than 1 mm) were used. As a buffer disk of an appropriate thickness was inserted into the seed/compact interface, the difference in Tc and ΔT in the three regions was much reduced. The composition analysis across the seed/buffer/compact region clearly revealed that the Tc decrease was caused by the samarium diffusion from a seed, which led to the formation of Y1?xSmxBa2Cu3O7?y in the Y123 compact region. The buffer insert technique was demonstrated to insure the uniform superconducting properties of the top surface of TSMG processed Y123 superconductors. 相似文献
995.
S.D. Park H.J. Kim B.J. Park Y.H. Han B.-H. Jun J.S. Lee C.-J. Kim 《Physica C: Superconductivity and its Applications》2011,471(21-22):880-883
The effect of calcium doping on the superconducting properties of top seeded melt growth (TSMG) processed Y1.5Ba2?xCaxCu3Oy superconductors was studied in terms of calcium content (Xca). YBa2?xCaxCu3O7?δ (Xca = 0, 0.005, 0.01, 0.02, 0.04, 0.1, 0.3) powders were synthesized by the powder calcination method. YBa2?xCaxCu3O7?δ powders were mixed with 0.25 mole Y2O3 powder and 1 wt.% CeO2 as Y2BaCuO5 (Y211) refiner, and finally made into Y1.5Ba2?xCaxCu3Oy (Y1.5) + 1 wt.% CeO2 composition. The single Y123 growth on the top surface was observed up to Xca = 0.1, while the multiple Y123 growth was observed at Xca ? 0.1. The superconducting transition temperature (Tc) and critical current density (Jc) of TSMG processed Y1.5 samples were inversely proportional to Xca. The Y211 size increased with increasing Xca due to the enhancement of Y211 coarsening by calcium doping. No Y211 refining effect by CeO2 was observed in the calcium doped samples. The Tc and Jc decrease by calcium doping are likely to be due to the calcium incorporation with the Y123 lattice and formation of coarse Y211 particles. 相似文献
996.
Yong-Hee Park Jungwon Kim Hyoungjoon Kim Ilsoo Kim Ki-Young Lee Dongjea Seo Heon-Jin Choi Woochul Kim 《Applied Physics A: Materials Science & Processing》2011,104(1):7-14
In this paper, we synthesize VLS-grown rough Si nanowires using Mn as a catalyst with various surface roughnesses and diameters
and measured their thermal conductivities. We grew the nanowires by a combination vapor-liquid-solid and vapor-solid mechanism
for longitudinal and radial growth, respectively. The surface roughness was controlled from smooth up to about 37 nm by the
radial growth. Our measurements showed that the thermal conductivity of rough surface Si nanowires is significantly lower
than that of smooth surface nanowires and decreased with increasing surface roughness even though the diameter of the smooth
nanowire was lower than that of the rough nanowires. Considering both nanowires were grown via the same growth mechanism,
these outcomes clearly demonstrate that the rough surface induces phonon scattering and reduces thermal conductivity with
this nanoscale-hole-free nanowires. Control of roughness induced phonon scattering in Si nanowires holds promise for novel
thermoelectric devices with high figures of merit. 相似文献
997.
Characterization of mitochondria isolated from normal and ischemic hearts in rats utilizing atomic force microscopy 总被引:1,自引:0,他引:1
Lee GJ Chae SJ Jeong JH Lee SR Ha SJ Pak YK Kim W Park HK 《Micron (Oxford, England : 1993)》2011,42(3):299-304
Mitochondria play critical roles in both the life and the death of cardiac myocytes. Various factors, such as the loss of ATP synthesis and increase of ATP hydrolysis, impairment in ionic homeostasis, formation of reactive oxygen species (ROS), and release of proapoptotic proteins are related to the generation of irreversible damage. It has been proposed that the release of cytochrome c is caused by a swelling of the mitochondrial matrix triggered by the apoptotic stimuli. However, there is a controversy about whether or not the mitochondria, indeed, swell during apoptosis. The major advantages of atomic force microscopy (AFM) over conventional optical and electron microscopes for bio-imaging include the fact that no special coating and vacuum are required and imaging can be done in all environments--air, vacuum or aqueous conditions. In addition, AFM force-distance curve measurements have become a fundamental tool in the fields of surface chemistry, biochemistry, and material science. In this study, we used AFM to observe the morphological and property changes in heart mitochondria that were isolated from a rat myocardial infarction model. From the shape parameters of the mitochondria in the AFM topographic image, it seemed that myocardial infarction caused the mitochondrial swelling. Also, the results of force-distance measurements showed that the adhesion force of heart mitochondria was significantly decreased by myocardial in infarction. Therefore, we suggested that myocardial infarction might be the cause of mitochondrial swelling and the changes in outer membrane of heart mitochondria. 相似文献
998.
We introduce a Fourier analysis of the waveform of periodic light-irradiance variation to capture Fourier coefficients for multichannel rotating-element ellipsometers. In this analysis, the Fourier coefficients for a sample are obtained using a discrete Fourier transform on the exposures. The analysis gives a generic function that encompasses the discrete Fourier transform or the Hadamard transform, depending on the specific conditions. Unlike the Hadamard transform, a well-known data acquisition method that is used only for conventional multichannel rotating-element ellipsometers with line arrays with specific readout-mode timing, this Fourier analysis is applicable to various line arrays with either nonoverlap or overlap readout-mode timing. To assess the effects of the novel Fourier analysis, the Fourier coefficients for a sample were measured with a custom-built rotating-polarizer ellipsometer, using this Fourier analysis with various numbers of scans, integration times, and rotational speeds of the polarizer. 相似文献
999.
A single-mode fiber (SMF) acousto-optic tunable filter (AOTF) with a tuning range of more than 300 nm is demonstrated. The SMF used in the experiment has a ring of symmetric holes within the cladding, which causes a larger mode-index difference between the first and the second higher-order antisymmetric modes than those of a conventional SMF. As a result, the difference in beatlengths between the core mode and the higher-order modes is highly increased, which makes it possible for the SMF AOTF to exhibit a single resonance peak in the transmission spectrum over the wavelength range of 1.3-1.6 μm for given acoustic frequencies of 3.1-3.8 MHz. 相似文献
1000.
We propose and experimentally demonstrate a novel design for temporal integration of microwave and optical intensity waveforms with combined high processing speed and a long operation time window. It is based on concatenating in series a discrete-time (low-speed) photonic integrator and a high-speed analog time-limited intensity integrator. This scheme is demonstrated here using a cascaded fiber-based interferometers' system (as a passive eight-point discrete-time integrator) and an analog time-limited intensity integrator. The latter is based on temporal intensity modulation of the input waveform with a rectangular-like incoherent energy spectrum followed by linear dispersion. Using this setup, we experimentally achieve accurate time integration of intensity signals with ~36 GHz bandwidths over an operation time window of ~4 ns, corresponding to a processing time-bandwidth product of >144. 相似文献