bluuebunny/crossref_metadata_2025 huggingface dataset:
Contributions of local and regional sources to fine PM in the megacity of Paris
Authors: Skyllakou K. , Murphy B. N. , Megaritis A. G. , Fountoukis C. , Pandis S. N.
Published: March 2014

Abstract. The particulate matter source apportionment technology (PSAT) is used together with PMCAMx, a regional chemical transport model, to estimate how local emissions and pollutant transport affect primary and secondary particulate matter mass concentration levels in Paris. During the summer and the winter periods examined, only 13% of the PM2.5 is predicted to be due to local Paris emissions, with 36% coming from mid-range (50–500 km from the center of the Paris) sources and 51% from long range transport (more than 500 km from Paris). The local emissions contribution to simulated elemental carbon (EC) is significant, with almost 60% of the EC originating from local sources during both summer and winter. Approximately 50% of the simulated fresh primary organic aerosol (POA) originated from local sources and another 45% from areas 100–500 km from the receptor region during summer. Regional sources dominated the secondary PM components. During summer more than 70% of the simulated sulfate originated from SO2 emitted more than 500 km away from the center of the Paris. Also more than 45% of secondary organic aerosol (SOA) was due to the oxidation of VOC precursors that were emitted 100–500 km from the center of the Paris. The model simulates more contribution from long range secondary PM sources during winter because the timescale for its production is longer due to the slower photochemical activity. PSAT results for contributions of local and regional sources were compared with observation-based estimates from field campaigns that took place during the MEGAPOLI project. PSAT simulations are in general consistent (within 20%) with these estimates for OA and sulfate. The only exception is that PSAT simulates higher local EC contribution during the summer compared to that estimated from observations.
Molecular corridors represent the multiphase chemical evolution of secondary organic aerosol
Authors: Shiraiwa M. , Berkemeier T. , Schilling-Fahnestock K. A. , Seinfeld J. H. , Pöschl U.
Published: March 2014

Abstract. The dominant component of atmospheric organic aerosol is that derived from the oxidation of volatile organic compounds (VOCs), so-called secondary organic aerosol (SOA). SOA consists of a multitude of organic compounds, only a small fraction of which has historically been identified. Formation and evolution of SOA is a complex process involving coupled chemical reaction and mass transport in the gas and particle phases. Current SOA models do not embody the full spectrum of reaction and transport processes nor do they identify the dominant rate-limiting steps in SOA formation. The recent advent of soft ionization mass spectrometry methods now facilitates a more complete molecular identification of SOA than heretofore possible. Based on such novel measurements, we show here that the chemical evolution of SOA from a variety of VOC precursors adheres to characteristic "molecular corridors" with a tight inverse correlation between volatility and molar mass. Sequential and parallel reaction oxidation and dimerization pathways progress along these corridors through characteristic regimes of reaction-, diffusion-, or accommodation-limited multiphase chemical kinetics that can be classified according to reaction location, degree of saturation, and extent of heterogeneity of gas and particle phases. These molecular corridors constrain the properties of unidentified products and reaction pathways and rates of SOA evolution, thereby facilitating the further development of aerosol models for air quality and climate.
Effect of enhanced pCO2 levels on the production of DOC and TEP in short-term bioassay experiments
Authors: MacGilchrist G. A. , Shi T. , Tyrrell T. , Richier S. , Moore C. M. , Dumousseaud C. , Achterberg E. P.
Published: March 2014

Abstract. It has been proposed that increasing levels of pCO2 in the surface ocean will lead to more partitioning of the organic carbon fixed by marine primary production into the dissolved rather than the particulate fraction. This process may result in enhanced accumulation of dissolved organic carbon (DOC) in the surface ocean and/or concurrent accumulation of transparent exopolymer particles (TEP), with important implications for the functioning of the marine carbon cycle. We investigated this in shipboard bioassay experiments that considered the effect of four different pCO2 scenarios (ambient, 550, 750 and 1000 μatm) on unamended natural phytoplankton communities from a range of locations in the northwest European shelf seas. The environmental settings, in terms of nutrient availability, phytoplankton community structure and growth conditions, varied considerably between locations. We did not observe any strong or consistent effect of pCO2 on DOC production. There was a significant but highly variable effect of pCO2 on the production of TEP. In three of the five experiments, variation of TEP production between pCO2 treatments was caused by the effect of pCO2 on phytoplankton growth rather than a direct effect on TEP production. In one of the five experiments, there was evidence of enhanced TEP production at high pCO2 (twice as much production over the 96 h incubation period in the 750 μatm treatment compared with the ambient treatment) independent of indirect effects, as hypothesised by previous studies. Our results suggest that the environmental setting of experiments (community structure, nutrient availability and occurrence of phytoplankton growth) is a key factor determining the TEP response to pCO2 perturbations.
Where does streamwater come from in low relief forested watersheds? A dual isotope approach
Authors: Klaus J. , McDonnell J. J. , Jackson C. R. , Du E. , Griffiths N. A.
Published: March 2014

Abstract. The time- and geographic sources of streamwater in low relief watersheds are poorly understood. This is partly due to the difficult combination of low runoff coefficients and often damped streamwater isotopic signals precluding traditional hydrograph separation and convolution integral approaches. Here we present a dual isotope approach involving 18O and 2H of water in a low angle forested watershed to determine streamwater source components and then build a conceptual model of streamflow generation. We focus on three headwater lowland sub-catchments draining the Savannah River Site in South Carolina, USA. Our results for a 3 year sampling period show that the slopes of the meteoric water lines/evaporation water lines (MWL/EWL) of the catchment water sources can be used to extract information on runoff source in ways not considered before. Our dual isotope approach was able to identify unique hillslope, riparian and deep groundwater, and streamflow compositions. The streams showed strong evaporative enrichment compared to the local meteoric water line (δ2H = 6.45 × δ18O + 6.26‰) with slopes of 2.52, 2.84, and 2.86. Based on the unique and unambiguous slopes of the EWLs of the different water cycle components and the isotopic time series of the individual components, we were able to show how the riparian zone controls baseflow in this system and how the riparian zone "resets" the stable isotope composition of the observed streams in our low angle, forested watersheds. Although this approach is limited in terms of quantifying mixing percentages between different end-members, our dual isotope approach enable extraction of hydrologically useful information in a region with little change in individual isotope time series.
A taxonomic review of the genus Asterostegus (Echinodermata: Ophiuroidea), with the description of a new species
Authors: Okanishi Masanori , Fujita Toshihiko
Published: March 2014

A revision of the genus Asterostegus Mortensen, 1933 (Echinodermata: Ophiuroidea: Euryalidae) is based on seven specimens, including the holotype of Asterostegus maini McKnight, 2003. A new species, Asterostegus sabineae sp. nov. is described from off Reunion Island and two other species, A. tuberculatus Mortensen, 1933 and A. maini, are redescribed. A tabular key to the three species of the genus Asterostegus is provided. Some terminology of the taxonomy of euryalid ophiuroids is revised.
Effect of Fe impurity on the dislocations in 4H-SiC: Insights from electrical and optical characterization
Authors: Chen Bin , Sekiguchi Takashi , Matsuhata Hirofumi , Ohyanagi Takasumi , Kinoshita Akimasa , Okumura Hajime
Published: March 2014

The effect of Fe impurity on the dissociation and motion behavior of basal plane dislocations (BPDs) in 4H-SiC homoepitaxial layers was investigated by electron-beam-induced current (EBIC) and cathodoluminescence (CL) techniques. Under the electron-beam irradiation, the BPDs dissociated to C- and Si-core partials, and these two partials were connected by another partial termed as X in this study. Stacking faults (SFs) were formed among these partials. The recombination activities of the BPDs and partials were enhanced with the existence of Fe impurity. The SFs near the surface region showed obvious dark contrast in EBIC, which was different from that observed in the clean samples. The X partial kept moving with sustained electron-beam irradiation whereas this partial in the clean samples stopped motion when it was connected to the sample surface. The dark contrast of the SFs and the peculiar motion behavior of the X partial are discussed with the CL results.
A Single Fiber Hydrophone of Interference Type Using Polarization-Maintaining Fiber
Authors: Takahashi Sumio , Kikuchi Toshiaki , Hasegawa Akio , Fukumoto Munenori
Published: March 2014

A single fiber interferometric detection scheme is tested for underwater sound detection. The interference of the X and Y components of a light propagating in a polarization-maintaining fiber is utilized. The output voltage increases linearly with sound pressure to 1.02×109 µPa and the minimum detectable sound pressure is 4.1×104 µPa·m/√H
z at 4.0 kHz. No fast fading of the output voltage is noticed. The frequency response has a peak at about 5 kHz as a result of a resonance vibration of the fiber coil, but this is not an inherent characteristic of the present detection scheme.
Ultrasonic MODEM by Phase Shift Keying
Authors: Mizutani Koichi , Toda Kohji
Published: March 2014

A method of realizing an ultrasonic MODEM by binary phase shift keying using two Lamb wave devices is described. The device operates as a phase shifter for constructing a binary phase shifted modulation signal, and as a comparator with a reference synchronous signal for demodulation. The device has two delay lines with a 180° acoustic phase difference in one substrate. The operation principle for the MODEM is given with experimental confirmation.
Trapped-Energy Piezoelectric Ceramic Resonator and Filter with Internal Electrodes
Authors: Inoue Takeshi , Utsumi Kazuaki , Suzuki Masanori , TAkahashi Sadayuki
Published: March 2014

A trapped-energy piezoelectric ceramic resonator, a double mode filter and a tandem structure filter with internal electrodes, operating in a thickness-extensional mode, are presented. The resonator and filters are produced by a multilayer ceramic technology. It has been experimentally ascertained that the resonator and filters show good energy-trapping characteristics due to the high electromechanical coupling for piezoelectric ceramic material, though ceramic layers cover both surfaces of the piezoelectric plate on which energy-trapping electrodes are formed. The possibilities of frequency adjustments by lapping the surface ceramic layers are also examined.
Interaction of Surface Acoustic Waves and Surface Polaritons
Authors: Nakagawa Yasuhiko , Matsukawa Tomokazu
Published: March 2014

The theoretical and experimental results of the interaction of a surface polariton (SP) and surface acoustic waves (SAW) are shown, where the conversion of an incident light by the SAW into SP and the diffraction of the SP by the SAW into a reflected light may be viewed as an interaction of the plane waves and surface polaritons induced by the SAW as “dynamic” gratings. As a result, we have confirmed a new resonance effect of the first diffraction order in the Raman-Nath light diffraction.
Existence of Negative Group Velocities in Lamb Waves
Authors: Negishi Katsuo
Published: March 2014

It is known only fragmentarily that negative group velocities exist in some lower modes of Lamb waves whose phase velocities are very high. This paper reveals numerically that the existence of negative group velocities depends not only on the frequency-thickness product but also on Poisson's ratio σ of the plate material. Negative group velocities exist in S1 mode for σ<0.45, and in A2 mode for σ<0.31. In addition, S3, S4, S6 and A5 modes exhibit negative group velocities in respective narrow ranges of σ.
Integrated Acoustooptic Device Modules for Communications, Signal Processing, and Computing
Authors: Tsai C. S.
Published: March 2014

Numerous advancements have been made in planar guided-wave acoustooptics in recent years. These advancements include analytical treatment of complex interaction geometry, design and fabrication of wideband Bragg modulators and deflectors (Bragg cells), and demonstration of a number of novel applications. The continuing progress in the fabrication and performance of other components including optical waveguides, waveguide lenses, diode laser sources and photodetector arrays, and their integration has significantly advanced the prospects for realization of integrated acoustooptic (AO) device modules and circuits. The most notable examples of such modules are the hybrid integrated optic RF spectrum analyzer and correlator in LiNbO3 substrate. In this paper some of the most recent advancements on guided-wave acoustooptics in LiNbO3 channel-planar and spherical waveguides and in GaAs planar waveguides made in the author's laboratory are reported. Emphasis is placed on realization and measurement of titanium-indiffused proton-exchanged (TIPE) microlens-based integrated Bragg modulator modules in LiNbO3 channel-planar composite waveguides. These integrated AO modules have been shown to take up a small substrate dimension (up to 2.0 cm) along the optical path and are also inherently of high modularity and versatility. Some applications of the LiNbO3 channel-planar waveguide- and spherical waveguide-based device modules for wideband multichannel integrated- and fiber-optic communications, signal processing, and computing are also described.
Ultrasonic Motor Using Flexural Standing Wave
Authors: Iijima Tamotu , Wada Masaaki , Nakagawa Yasuhiko , Itoh Hiroshi
Published: March 2014

A flexural standing wave excited in elastic board has vertical and horizontal components of oscillation. By causing a collision between the two components the standing wave can drive a slider.
Multilayer Piezoelectric Actuators for Scanning Tunneling Microscope
Authors: Mikoshiba Nobuo , Morita Seizo , Ishigame Yuri
Published: March 2014

We report a new type of a three-dimensional (3D) mechanical translator, i.e., a double tripod which has two sets of 3D-scanning mechanisms in one tripod. For elements of the double tripod, we used multilayer piezoelectric actuators whose electrodes were cut into two parts with displacement/voltage constants with different orders of magnitude: A∼1070 Å/V and B∼108 Å/V. By measuring a series of STM images with the double tripod, we showed that the additional SD-scanning mechanism is useful as a 3D-positioner for a selection of the scan window.
Studies on Ultrasonic Vibration Press of Powder by Longitudinal Vibration Punches and Various Vibration Mode Dies
Authors: Tsujino Jiromaru , Yabuzaki Motohiro , Ueoka Tetsugi
Published: March 2014

An ultrasonic vibration press of powder using 20 kHz upper and lower longitudinal vibration punches, and various 27 kHz or 20 kHz vibration mode dies is studied. The punches are driven at antiphase or inphase vibration mode at a compacting position. The vibration dies used are (A) radial, (B) longitudinal and (C) complex vibration dies. These vibration punches and dies are driven by independent vibration controllers and from 1 to 3 kW power amplifiers. In the copper powder specimen, the increment of compact density by these vibrations is over 20% at a static compacting pressure of 200 MPa.
Optimum Design Procedure for Multi-Pinhole-Plate Ultrasonic Atomizer
Authors: Maehara Naoyoshi , Ueha Sadayuki , Mori Eiji
Published: March 2014

An optimum design procedure of the vibrating system for a Multi-Pinhole-Plate ultrasonic atomizer has been studied. It is composed of a thin plate with many pinholes and a circular ring piezoelectric element.
The greatest efficiency was achieved at under two conditions. One was the coincidence among the first resonance frequencies of the inner portion inside the element and the outer portion and the second resonance frequency of the entire system. The other was when the inner diameter of the element was equal to that of the second nodal circle of a circular plate.
Basic Analysis of A Pulsed Photoacoustic Microscope
Authors: Kasai Masanobu , Ishioka Muneharu , Kaihara Mikio , Harata Akira , Sawada Tsuguo , Gohshi Yohichi
Published: March 2014

Pulsed PZT-PA and PBD (photothermal beam deflection) signals were measured, and the differences in their generation mechanisms discussed between them using FEM (finite elements method). A pulsed photoacoustic imae for a model sample having subsurface structures was also demonstrated.
High Dynamic Range Integrated-Optic Spectrum Analyzer Using Total Internal Reflection in a Waveguide
Authors: Nishimoto Hiroshi , Kitano Toshihiko
Published: March 2014

An integrted-optoc spectrum analyzer, using total internal reflection in a waveguide, is proposed and demonstrated. For real time multifrequency analysis, a low diffraction efficiency operation is required to operate under conditions of low level spurious components generation. The proposed structure, which has been fabricated on Z-cut LiNbO3, makes it possible to realize a high dynamic range at a few percent diffraction efficiency. The completed device has exhibited a 25–28 dB RF dynamic range in multifrequency analyzing operation.
Wavelength-Multiplexed Optical Signal Processing Using Channel-Type Acousto-Optic Switches
Authors: Goto Nobuo , Miyazaki Yasumitsu
Published: March 2014

Collinear acousto-optic (A-O) switches have potential in the processing of wavelength-multiplexed optical signals. These optical signals can be switched by surface acoustic waves independently of one another. By taking advantage of this excellent feature, a variety of signal processors can be formed with the channel-type A-O switches. As examples, an optical frequency shifter, a switching matrix for signal exchanges and matrix multiplying devices are discussed. These signal processors are composed of integrated optic devices.
Ultrasonic Spectrometer for Solutions of Biological Material
Authors: Sakka Toshiaki , Mitaku Shigeki
Published: March 2014

A new ultrasonic apparatus was developed for relaxation measurements of biological materials, and was equipped with two kinds of electric circuits for the resonance method and the pulse method. The frequency range was extended to the lower side by using concave quartz transducers of 3 MHz. The relative accuracy of the apparatus was better than 5×10-5 for the ultrasonic velocity, and the accuracy of the absorption per wavelength was about 1×10-4 throughout the frequency range from 670 kHz to 35 MHz. The sample volume was 1 ml and the minimum dry weight of biological material for measurements was 1 mg.
Ultrasonic Technique for the Study of Solid-Liquid Interface in Metallic Alloys
Authors: Suzuki Kenjiro , Hikata Akira , Elbaum Charles
Published: March 2014

We have developed a new ultrasonic technique which realizes the in site or “real time” observation of the solid-liquid interface (SLI) in metallic alloys. In this technique, the location and velocity of the SLI can be determined from the transit time measurements of the echo from the SLI. The roughness of the interface can also be determined from amplitude measurements of the echo. This technique has been successfully applied to the observation of directional solidification in tinalloys.
Electromagnetic Transducer with Convex Copper Vibration Membrane by DC Diode Sputtering Technique
Authors: Endoh Nobuyuki
Published: March 2014

An ultrasonic electromagnetic type transducer composed of a convex coil and vibration membrane is good for radiation of a short intense pulse sound into a wide area. The author used a DC diode sputtering technique to make a convex vibration membrane. The 35 mm diameter convex transducer radiated a few cycles pulse sound of 1 MHz. The measured directivity and peak sound pressure distribution approximately coincided with the numerical calculations. Despite a large vibration surface, it had a very wide directivity of ±13 degrees at -6 dB. This technique is useful for making another complex vibration surface transducer.
Endfire Radiation of Acoustic Helical Antennas
Authors: Hasegawa Akio , Takahashi Sumio , Kikuchi Toshiaki , Fujita Teruaki
Published: March 2014

In this paper, two acoustic helical antenna properties are investigated both theoretically and experimentally. First, a comparison of the directional patterns between an ordinary endfire helix and a Hansen-Woodyard helix is presented, and the superiority of the former is discussed. Second, the effects of two helix parameters on the directional patterns of the ordinary end fire helix are examined. It is shown that increase in helix diameter and length leads to a decrease in the main lobe width without raising the side lobe level.
Simulation of Interfacial Interaction Effects on Electro-Optic Switching in Ferroelectric Liquid Crystals
Authors: Nakamura Toyokazu , Ichinose Hideo , Naemura Shohei
Published: March 2014

The simulation of ferroelectric liquid crystal switching dynamics revealed that director depending interfacial interaction between liquid crystal molecules and substrate surface has a pronounced effect on FLC switching processes. When the interfacial interaction is strong, switching processes have multiple steps, polarization reversal current shows multiple peaks and optical response time becomes long. Especially, if the interfacial interaction polar component is large, optical stability is decreased. This simulation enables designing ferroelectric liquid crystal switching devices with fast response and good optical bistability.
Fabrication of Transparent PLZT Ceramics with a High Transmittance and Their Application to Optical Light Shutter
Authors: Hayashi Kunihiko , Okamoto Susumu , Takada Hiroshi , Nagamori Yoshitaka , Okada Hideya , Maeoka Toshiaki , Yamamoto Takashi
Published: March 2014

Lanthamun-modified lead zirconate titanate (PLZT) powders were produced by chemical preparation method and these powders were sintered by ordinal atmosphere sintering method with O2-gas flow. As a result of combination both high quality powder and atmosphere sintering, high transparent PLZT ceramics with a transmittance as high as 67% at the wavelength of 600 nm were obtained. Optical light shutters were produced using these PLZT ceramics and proved to be applicable for commercial use.
Acoustic Emission in Piezoelectric/Electrostrictive Actuators
Authors: Uchino Kenji , Hirose Terukiyo , Varaprasad Ande Murali
Published: March 2014

Acoustic Emission(AE) has been measured in piezoelectric/electrostrictive actuators. Usual unipolar driving does not generate strong AE in the ceramic actuators. After suffering from thermal shock, the sample becomes to reveal the AE signal. These results suggest that the AE signal is a good indication to predict electrical/mechanical breakdown of the ceramic actuators.
1.86 GHz SAW Filter
Authors: Kasanami Toru , Ieki Hideharu , Koike Jun
Published: March 2014

Using the third order harmonic wave of Sezawa-mode which propagates in ZnO films epitaxially deposited on R-plane sapphire, high performance filter which is a low insertion loss of 9 dB at 1.86 GHz has been realized.
Properties of Glass-added Barium Titanate Based Ceramics Fired in a Reducing Atmosphere
Authors: Kishi Hiroshi , Murai Shunji , Chazono Hirokazu , Oshio Minoru , Yamaoka Nobutatsu
Published: March 2014

Electrical properties and microstructures of glass-added barium titanate ceramics were studied. Resistivities of the ceramics were increased markedly by addition of glass components when they were fired in a reducing atmosphere. The flat temperature dependence of dielectric constant were obtained by substituting small amount of Sr and Ca for barium site under the presence of glass components. The multilayer ceramic chip capacitors with nickel electrodes which meet X7R specification have been developed. They exhibited high resistivity (>1012 Ωcm) and high dielectric constant (K=3300).
Effects of Shape and Volume Fraction of Closed Pores on Remanent Polarization and Coercive Force of Ferroelectric Ceramics
Authors: Banno Hisao
Published: March 2014

Theoretical equations for remanent polarization and coercive force of ferroelectric ceramics with closed pores are derived as a function of shape factor and volume fraction of closed pores, based on the modified cubes model. This theory is applied to the experimental results obtained by Nagata with good agreement between theoretical and experimental ones.
Dielectric Properties of PbO–ZrO2–REOx Ceramics at Microwave Frequencies
Authors: Tatsuki Koichi , Murano Kanji , Kawamura Toshiyuki , Kato Hiroshi , Yano Shinsuke , Nishigaki Susumu
Published: March 2014

The dielectric properties at microwave frequencies of PbO–ZrO2–REO
x
caramics prepared by hot-press sintering were investigated. The PbZrO3 ceramics modified by rare-earth oxides especially CeO2, Gd2O3 and Tb4O7 showed a high dielectric constant, a high Q value and a negative temperature coefficient of the resonant frequencies. To combine this with a conventional ceramic having a positive τ
f
, we made a dielectric resonator which exhibited ε

r
=170, Q=1200 and τ
f
=80 ppm/°C at 3 GHz.
Furthermore, the application of this resonator enabled the development of a miniturized high characteristic band-pass filter.
Maltilayer Ceramic Capacitor with Copper Electrode
Authors: Kato Junichi , Yokotani Yoichiro , Kagata Hiroshi , Niwa Hiroshi
Published: March 2014

Dielectric material of (Pb
a
Ca
b
){(Mg1/3Nb2/3)Ti(Ni1/2W1/2)}O2+a+b
, where a+b>1, has been investigated. This composition has been proved to be fired under low oxygen partial pressure of less than 10-1 Pa with high resistivity. To make multilayer ceramic capacitor, the dielectric material was co-fired with copper electrode in an atmosphere of intermediate oxygen pressure. The obtained capacitor met to Z5U specification and had low dissipation factor and small change of capacitance under a d.c. bias voltage.
SrTiO3 Base BL Capacitors Prepared by Vapor Phase Diffusion
Authors: Toyoda Junichi , Murano Kanji
Published: March 2014

When a PbO–Bi2O3–Cu2O system vapor phase diffusion was applied to an SrTiO3–base semiconductive ceramic, a BL capacitor with a high apparent permittivity of 28500, a low dissipation factor of 0.3%, and a high resistivity of 2.6×1011 Ω cm was obtained.
Influence of Electric Field and Cell Thickness on Dielectric Behaviour of Ferroelectric Liquid Crystal at Phase Transition
Authors: Yoshino Katsumi , Nakao Kenji , Taniguchi Hiroki , Ozaki Masanori
Published: March 2014

Under dc bias field, in thin cell and at high frequency in which the Goldstone mode originated in the fluctuation of azimuthal angle of molecular long axis is suppressed, a sharp dielectric constant peak at the phase transition between smectic-C and smectic-A phases (Curie point) has been clearly observed, which is interpreted in terms of the Soft mode contribution.
The deviation of the temperature T
m of dielectric constant peak from the phase transition temperature under no bias field T
0 is found to increase under dc bias field E with the relation of (T
m-T
0)∝E
2/3. The peak dielectric constant ε
p is also found to be suppressed by the field E in proportional to ε
p∝E
-2/3.
These results support that the phase transition of these compounds is of the second order.
Finite Element Analysis of Energy-Trapped Second Harmonic Thickness Extensional Vibration
Authors: Okada Tsutomu , Kittaka Toshihiko , Ando Akira , Sakabe Yukio
Published: March 2014

A second harmonic mode in a piezoelectric plate with an internal electrode is analyzed by means of the finite element method. This paper shows that although energy-trapping cannot be realized in a PbTiO3 piezoelectric plate for a fundamental mode, it is possible for a second mode.
Characteristics of Surface Acoustic Waves Propagating on Bi12GeO20 Substrate
Authors: Murota Masao , Shimizu Yasutaka
Published: March 2014

The propagation characteristics of Rayleigh wave and leaky surface wave on Bi12GeO20 substrate were theoretically calculated by changing Euler's angle, and the theoretical contour maps for the phase velocity, electro-mechanical coupling constant K
2, and temperature coefficient of delay (TCD) of Rayleigh wave were displayed. From these results, it was found that the minimum value of TCD is 108 [ppm/°C].
An Analysis of an Equivalent Circuit Model for an Interdigital Surface-Acoustic-Wave Transducer
Authors: Kojima Toshihiro , Shibayama Kimio
Published: March 2014

This paper presents a new and simplified equivalent circuit model for an IDT. The model developed here provides more accuracy than the well-known crossed field Smith-model, since it contains the energy storage effect in addition to usual secondary effects. By applying the image parameter theory to the new model, the admittance matrix Y
ij of the equivalent three-port model for an N-pair IDT has been derived in concise closed form. As an application, the relations of the radiation conductances to metallization ratios for an IDT are investigated.
Sputter Deposition for High Power Durable SAW Electrodes
Authors: Yuhara Akitsuna , Watanabe Hitoshi , Hosaka Norio , Yamada Jun , Iwama Akira
Published: March 2014

DC magnetron sputtering of Al and Al alloy is studied to fabricate high power durable SAW electrodes. Experiments on SAW resonators as a test medium show that the time to failure is inversely proportional to the cube of SAW power in the sputtered Al films. Structure analyses and measurements on static stress reveal the following: the reduced static stress has a significant effect on higher durability to SAW power in the sputtered Al electrodes, and in addition, reduction of grain size in the films results in higher resistance to mechanical migration.
An Ultrasonic Modulator for 16-Valued Frequency Shift Keying
Authors: Mizutani Koichi , Toda Kohji
Published: March 2014

A Lamb wave delay line oscillator with four terminated transducers is described as playing a key role in 16-valued frequency shift keying (16-FSK) modulation. For the oscillation of 16-valued frequencies, four transducers located at the central part of the Lamb wave device are used to feed 4-bit modulating signals via two field effect transistors as voltage-dependent resistors. The experimental results on 16-valued frequency modulation using the 10.6 MHz Lamb wave device are in good agreement with the operation principle.
Ultrasonic CT by Finite and Boundary Element Methods
Authors: Miyashita Toyokatsu , Ueda Eiji , Shikata Hiroyuki
Published: March 2014

We propose a new approach to diffraction tomography. We solve the wave equation, which governs the propagation of sound through a medium with spatially varying material parameters, using a combination of the finite element method and boundary element method. A computer simulation shows fine and quantitatively exact reconstruction of the two-dimensional distribution of refractive index and absorption coefficient of the material. This method is applicable not only to ultrasonic CT but also to microwave CT.
A Digital Phase Delay Compensation Beam-Forming Scheme for Ultrasonic Imaging
Authors: Horiguchi Toshio
Published: March 2014

This paper describes an efficient digital implementation scheme of the phase delay compensation beam-former (PBF) for acoustic imaging using arrays, which is based on direct quadrature demodulation through sampling for narrowband signals. The scheme eliminates the need for analog quadrature demodulators employed in conventional digital PBFs and enables the sampling frequency to be reduced lower than the Nyquist rate. The lower bound of sampling frequency, within which images can be reconstructed without unacceptable degradation, has been experimentally studied by Bmode imaging in air using a microphone array.
Determination of Some Flame Parameters using Laser-induced Ultrasonics
Authors: Harata Akira , Sawada Tsuguo
Published: March 2014

A new method of combustion diagnostics is described. A technique using laser-induced coherent ultrasonic waves is applied for temperature measurement. The ultrasonic waves are generated via thermal expansion resulting from light absorption and subsequent nonradiative relaxation in an interference pattern of two crossed pulse beams split from one excitation-laser pulse. They are detected by Bragg diffraction of a probe laser. Ultrasonic velocity measurements taken on a candle flame with light absorbing soot demonstrate that localized temperature values can be estimated.
Photoacoustic Effect in Melting and Freezing in Pure Metals
Authors: Kojima Seiji
Published: March 2014

The temperature dependence of photoacoustic signals has been studied on pure metals in the neighborhood of melting and freezing points. The dramatic decrease of the photoacoustic amplitude was found at both melting and freezing points. The modulation frequency dependence of the temperature variation was also investigated.
Investigation of Nonradiative Processes and Defects in Semiconductors by Photoacoustic and Photo-Thermal-Radiation Techniques
Authors: Mikoshiba Nobuo , Tsubouchi Kazuo
Published: March 2014

A review is given of our investigation of nonradiative processes and defects in semiconductors by photoacoustic and photo-thermal-radiation techniques. The main results obtained so far are summarized as follows. (1) The spatial distribution of oxidation-induced stacking faults in Si wafers can be observed by a scanning photoacoustic topograph. (2) The spatial distribution of microdefects in GaAs wafers can be observed by a scanning photo-thermal-radiation microscope.
Velocity Measurement in Liquids by using Reflection Type Ultrasonic Correlator via Wave number Analysis in MHz Range
Authors: Imano Kazuhiko , Sannomiya Toshio , Chubachi Noriyoshi
Published: March 2014

A modified version of an ultrasonic correlator system introducing wave number analysis (complex FFT) for velocity measurement in liquids is demonstrated. To test the performance of the system, experiments and computer simulation were made on the relationship between measurement accuracy and S/N or length of data. It is concluded that complex FFT analysis was found to be effective for the measurement, and accuracy of better than 0.1% was successfully evaluated by computer simulation.
Ultrasonic Properties in Woods
Authors: Sakai Harue , Takagi Kenshiro , Minamisawa Akiko
Published: March 2014

Ultrasonic velocity and absorption were observed at 1∼4 MHz in nine different kinds of woods. They showed a strong anisotropic feature: the direction of growth (L) has the fastest velocity and smallest absorption; the direction perpendicular to annual rings (R) has the second; and the direction tangential to them (T) has the slowest velocity and largest absorption. The fastest velocity ranges 5000∼6000 m/s and V
L:V
R:V
T≃1:0.4:0.3. Absorption shows a linear increase with frequency up to 4 MHz. Velocity was also observed as a function of the moisture content of woods. It decreases rapidly with the moisture content up to a certain point around 30% and thereafter the decrease is very slow. This point gives the fiber saturation point of wood.
Simple Measurement Method of Nonlinearity Parameter B/A of Tissue by Propagation Time Difference
Authors: Endoh Nobuyuki , Uehara Masato , Ogata Hajime , Miyawaki Kyoko , Kohno Miyuki
Published: March 2014

A simple measurement method was developed for obtaining the nonlinearity parameter B/A of soft tissue in vitro by an ultrasonic gated pulse of 6.8 MHz. The propagation time through tissue was measured twice, changing its thickness. The B/A of tissue should be estimated by the thickness difference and the propagation time difference between atmosphere and pressurized (3 atoms) condition. A fundamental experiment was carried out to confirm the validity of the method. A two channel synthesizer was used to measure the time difference. The mean B/A of water was 5.0. We also obtained B/A of 9.2 for chicken liver in vitro.
Requirements for Science in NDE
Authors: Heyman Joseph S.
Published: March 2014

Nondestructive Evaluation (NDE) is the technology of measurement, analysis, and prediction of the state of material systems, for safety, reliability and mission assurance. It is an old technology yet still in its infancy. The opportunities for research and application are great and the shortfall in technology demands attention. In this paper, we shall review aspects of aerospace NDE and discuss recent advances in ultrasonics for aerospace applications.
Acoustic Waves in Soft Biological Tissues
Authors: Hatta Ichiro
Published: March 2014

Soft biological tissues are a complex system composed of water, proteins, lipids and other substances. In this review article, the elastic properties of such biological tissues are considered within a framework of condensed matter physics.
Ultrasonic Butt Welding of Anticorrosive Aluminum and Copper Plate Specimens
Authors: Tsujino Jiromaru , Ueoka Tetsugi , Nakahama Yoshinori , Daigo Hiroshi , Tsuboi Shunichi , Fukazu Yasuo
Published: March 2014

Ultrasonic butt welding of anticorrosive aluminum and copper plate specimens is studied. Ultrasonic butt welding equipment of 19 kHz frequency is used. The ultrasonic vibration source uses eight bolt-clamped Langevin type PZT transducers of 50 mm diameter driven by 10 kW to 50 kW power amplifiers. Welding specimens used are anticorrosive aluminum and copper plates of 6 mm thickness and 7 mm to 14 mm width. These welding specimens are successfully joined end to end with anticorrosive aluminum specimen strength of about 250 MPa. Required power for joining these specimens is 7-9 kW/cm2.
Fundamental Study in Extracorporeal Shock Wave Lithotripsy Using Piezoceramics
Authors: Okazaki Kiyoshi , Aida Satoshi , Iwama Nobuyuki , Kuwahara Masaaki , Takayama Kazuyoshi
Published: March 2014

An experimental extracorporeal shock wave lithotripsy system consisting of a piezoceramic shock wave generator and an ultrasonic imaging apparatus has been made. The generated 500 kHz ultrasound wave converts to the shock wave in the focussing region by nonlinear interaction. The measured peak pressure at the focussing point is 130 MPa and the focussing region, in which pressure is more than half of the peak pressure, is about φ3 mm in width and 13 mm in depth. Model urological stones in water and a human renal stone implanted in the right renal pelvis of a mongrel dog are successfully disintegrated into less than φ3 mm fragments.
An Estimation of Randomness of Scattering Media by Power Spectrum of Ultrasonic Scattering Wave
Authors: Kikuchi Tsuneo , Kiryu Shogo , Sato Sojun , Miura Hajime
Published: March 2014

Two methods are shown for characterizing shapes of a power spectrum to estimate distribution (randomness) of the spacings of the scatterers. One method is FFT of cepstrum (FFTC). The other is fractal-based analysis which is useful for characterization of complex figures such as geometry. Using a one-dimensional scattering model, trial estimations of the randomness of the scatterers were performed, and it was found that the randomness could be discriminated by both methods.
Transducer Matching in Ultrasonic Traveling Wave Interferometric Network Method
Authors: Nakajima Haruhiko , Hama Aritsune , Minami Shigeo , Takeuchi Takashi
Published: March 2014

In the ultrasonic TWIN method thickness controlled silver layers were deposited on the surfaces of a sapphire disk pair making the resonant frequencies exactly coincide up to higher overtones. The optimum thickness for the respective disks was found to be 1 µm and 5 µm. An improved transducer system was successfully implemented at frequencies from 30 MHz to 350 MHz.
Electronic Linear Acoustic Beam Scanning Using an Interdigital Transducer
Authors: Nomura Tooru , Shibata Shinichi , Yasuda Tsutomu , Shiokawa Showko
Published: March 2014

Acoustic beam scanning using an interdigital transducer (IDT) is described. A broad band IDT for beam scanning was constructed on piezoelectric substrate. The broad band IDTs consist of interdigital electrodes whose period and width are gradually changed. When the frequency of applied voltage is changed from 15 to 45 MHz, a 0.9 mm wide beam in water can be shifted to a length of 9 mm. This new IDT for acoustic waves is useful for an imaging system of high speed scanning.
Ultrasonic Study on SBS Block Copolymer in Solutions
Authors: Nomura Hiroyasu , Koda Shinobu , Nishimura Riichi
Published: March 2014

Ultrasonic velocity and absorption coefficient of the solutions of SBS block copolymer in various solvents were measured. From the data on ultrasonic velocity and density in solutions, partial specific adiabatic compressibility was obtained. The additivity of the compressibility in copolymer was discussed. The ultrasonic relaxation phenomena were observed in the frequency range from 0.2 to 800 MHz and their relaxation spectra were expressed by a double relaxation equation. The relaxation spectra of SBS block copolymer were strongly dependent on the solvent, especially for the relaxation process in the lower frequency region.
Acoustic Pulse Generation in Water by Pulsed Proton Beam Irradiation and its Possible Application to Radiation Therapy
Authors: Hayakawa Yoshinori , Tada Junichiro , Inada Tetsuo , Wagai Toshio , Yosioka Katuya
Published: March 2014

Acoustic pulse generation in water irradiated by pulsed proton beam was observed. The dose rate of the beam was 0.05 Gy/pulse and 0.0025 Gy/pulse. A hydrophone sensitive to the acoustic frequency band between 0 to 300 kHz was used for detection. The detected acoustic pulse in water was qualitatively the same shape as the depth dose distribution of the proton beam, when the depth scale is divided by the sound velocity. The intensity of the generated acoustic pulse is believed to allow monitoring of the radiation dose distribution in patients irradiated by pulsed heavy charged particle beam.
Velocity Measurements of Laser-Generated Ultrasound at High Temperatures
Authors: Nakano Hidetoshi , Nagai Satoshi
Published: March 2014

The temperature dependence of ultrasonic velocities is determined by a laser-ultrasound technique in a non-contact manner for several kinds of materials. A pulsed Nd:YAG laser is used to generate ultrasound on the surface of a specimen while a He-Ne laser interferometer detects the subsequent displacement on the directly opposite surface. The results are favorably compared with those obtained with a conventional contact ultrasonic technique. The longitudinal velocities of both methods agreed within 0.4% or less in the range from room temperature to 800°C.
Evaluation of Multilayer Structure and Depth Profile by PAS Using a Transparent Transducer
Authors: Hata Tomonobu , Adachi Sakae , Horita Susumu
Published: March 2014

This paper concerns the experimental evaluation of optical properties of a multilayer semiconductor structure by PAS using a transparent transducer method. The sample is a Ga
x
In1-x
P(1.8 µm)/GaAs (380 µm)/Si(530 µm). Optical absorption edges of this sample are evaluated from PA amplitude and phase signals. Between two layers a sharp dip of the PA signal is observed which corresponds to the absorption edge. Generation mechanism of the PA dip is discussed in comparison with the phase delay of two signals.
Photodarkening Effect of Amorphous Chalcogenide Thin Films Induced by Acoustic Domain
Authors: Tokunaga Yoshiaki
Published: March 2014

The photodarkening effect of chalcogenide amorphous thin film evaporated on sapphire by domain fluxes is discussed. Our experimental results: First, optical transparency curves of thin film shifted to longer wavelength in ranging from 480 nm to 580 nm before and after experiencing domain fluxes. Second, the absorption curve for V-polarized light was shifted toward a shorter wavelength than that of H-polarized light. Third, the curve for V-polarized light was qualitatively about 10% darker than that of H-polarized light at about 480 nm.
An Omnidirectional Transducer Design Attached with High Sound-Speed Material for Use in Deep Seas
Authors: Hachiya Hiroyuki , Ohtsuki Shigeo , Okujima Motoyoshi
Published: March 2014

For ultrasonic transducers employed in deep seas, omnidirectivity is often required. In this paper, an omnidirectional transducer for use in deep seas is designed. To realize a transducer with desired directivity under high hydro-pressure, a new type of construction utilizes a high-sound-speed material called syntactic foam attached to a cylindrical transducer element. Numerically designed results for the omnidirectional transducer using finite element analysis considering an infinite space agree well with measured directivity patterns, and the design of a transducer with desired directivity for use under high hydro-pressure in deep seas is found to be possible.
ZnO-Film/Si-Diaphragm Underwater Ultrasonic Transducers
Authors: Suzuki Hiroshi , Hashimoto Ken-ya , Yamaguchi Masatsune
Published: March 2014

The application of composite resonators of ZnO-film/Si-diaphragm and ZnO-film/SiO2-diaphragm structures to underwater ultrasonic transducers is described. Theoretical analysis has suggested that proper thicknesses for the film and diaphragm make the resonator a wide bandwidth, high efficiency transducer. A resonator of ZnO-film/(AIN-film)/Si-diaphragm structure was fabricated and shown to work successfully as an underwater ultrasonic transducer, realising a -3 dB bandwidth of 12 MHz at the centre frequency of 124 MHz without any appreciable spurious responses.
Analysis of Diffracted Wave by a Thick Circular Plate
Authors: Utsumi Hiroyuki , Ouchi Hirobumi , Tabei Makoto , Ueda Mitsuhiro
Published: March 2014

We recently developed a diffraction theory for solid obstacles. The waves diffracted by a thick circular plate are estimated by this theory and the results are compared with those obtained by experiments. The comparison shows the validity and a limitation of our theory.
Method of Measuring VHF Elastic Vibration Modes by Optical Sensing
Authors: Hirose Yasuo , Kitajima Mototaka , Tsuzuki Yasuo
Published: March 2014

This paper describes an optical measurement method of elastic vibration modes with extremely small vibration amplitudes in the very high frequency (VHF) range. The measurement system is an optical fibre interferometric sensor, in which optical phase modulations caused by elastic vibrations under study are detected and processed to give the vibration amplitudes. Extensive use of recent optical fibre technology and a signal processing technique enabled us to achieve detailed measurements of vibration modes with amplitudes as small as 0.1 Å at frequencies as high as 150 MHz.
Novel Method for Aligning Ferroelectric Liquid Crystal on Substrate
Authors: Chen Guo-Ping , Nakamura Toyokazu
Published: March 2014

We have depeloped a novel method for transferring a well aligned ferroelectric liquid crystal (FLC) thin film onto a solid substrate. A free-standing FLC film has been successfully obtained on a solid substrate with this method. A homeotropic alignment in smectic phase has been confirmed with polarizing microscope and X-ray diffraction. We will report this novel method for transferring a free-standing film and discuss some applications of this film.