bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrasonic Spectroscopy in Liquid Bromoform
Authors: Takagi Kenshiro , Ozawa Harue
Published: March 2014

The ultrasonic velocity and absorption were observed in liquid bromoform near room temperature. Three experimental techniques, pulse-echo overlap, HRB and Brillouin scattering, were used complementarily to survey the frequency range from 3 MHz to 5 GHz. The obtained spectra showed a typical curve for double-step relaxation, one centered at 92 MHz and the other at 6.5 GHz at 20°C. The results were successfully described with a hypothesis of the vibrational relaxation process characterized by two time constants: the lowest and the second lowest vibrational modes relax cooperatively within 30 ps, while all those above the third are governed by the other process at 2 ns.
Sound Velocity in Critical Binary Mixtures
Authors: Tanaka Hajime , Nakajima Haruhiko , Wada Yasaku
Published: March 2014

This paper describes the significance of sound velocity measurement in exploring the acoustic anomaly of critical binary mixture and the methods for measuring ultrasonic and low frequency sound velocities in such a mixture.
Measurements of Band-Edge and Intervalley Phonons in Semiconductors by Magnetophonon Resonance
Authors: Hamaguchi Chihiro , Shimomae Koichi , Hirose Yoshikazu
Published: March 2014

Magnetophonon resonance experiments of longitudinal magnetoresistance are carried out using the magnetic field modulation and second harmonic detection method to investigate band-edge phonons in n-InSb and n-GaAs and to determine the intervalley phonons in n-Ge and n-Si. The TA phonon energies were determined to be 4.8 meV at the X point and 5.1 meV at the (0.6, 0, 0) point in n-InSb and 9.8 meV at the X point in n-GaAs. The intervalley phonon energy was found to be 30.0 meV (X

1
) in n-Ge. Many intervalley phonons were observed in n-Si and that with the strongest interaction with electrons was found to be 47.8 meV which is an f-type intervalley phonon.
Dielectric Properties of PLZT Epitaxial Thin Films
Authors: Adachi Hideaki , Kawaguchi Takao , Kitabatake Makoto , Wasa Kiyotaka
Published: March 2014

Epitaxial PLZT(x/0/100) thin films were successfully grown on c-plane sapphire substrates. Their dielectric and electrooptic properties were measured for the first time. The ferroelectricity was observed for the films of x≤28 composition. The PLZT(28/0/100) thin film had strong electro-optic effect and this will be one of most useful candidates for making thin film integrated optic devices.
The Polarization-Reversal Characteristics of Pb(Zr, Ti)O3 Family Ceramics
Authors: Masuda Yoichiro , Baba Akira , Jyumonji Masanori , Kasai Kiyokazu
Published: March 2014

The polarization switching characteristics of PLLZT10/65/35, PLZT5/65/35 and PZT65/35 ceramics were investigated. The switching time and switching current density were read from the transient wave form. The switching time ts of PZT65/35, PLZT5/65/35 and PLLZT10/65/35 ceramics were 86µs, 105µs and 125µs at 30°C, respectively. The electric field dependence of switching time can be described by a well-known formula ts=kE-n. The photoelectric response of some FE/PC devices was elucidated.
Properties of Grain-Oriented Transparent (Pb, Ba, La)Nb2O6 Ceramics
Authors: Nagata Kunihiro , Kawatani Yasushi , Okazaki Kiyoshi
Published: March 2014

The dielectric, piezoelectric and optical properties of grain-oriented (Pb
x
Ba1-x
)1-3y/2La
y
Nb2O6 ceramics were studied. The dense grain-oriented samples with various compositions of x=0.40–0.80 and y=0–0.10 were prepared by hot-pressing. The compositions with x=0.55–0.60 and y=0.02–0.04 showed a coupling factor for thickness-mode of more than 40% and a mechanical quality factor of less than 10. They also showed the high optical transmittance corresponding to PLZT ceramics. Compositions with x=0.55–0.65 and y=0.06–0. 10 showed a transmittance of 60–65% at a wave-length of 0.7–6 µm.
A PLZT Light Shutter with Low Power Consumption
Authors: Murano Kanji , Himuro Masami , Watanabe Yoshihisa , Matsumoto Shigeo , Nishigaki Susumu
Published: March 2014

To reduce the power consumption of a PLZT light shutter and the driving voltage change of it with the environmental temperature, we investigated the relation between halfwave voltage and temperature in various PLZT compositions. Compositions which showed a memory effect at room temperature showed large transverse quadratic electro-optic coefficients at temperatures higher than room temperature. We found these compositions required less power when the PLZT was kept at the higher temperature. A shutter consisting ofa PLZT with the composition 7.3/65/35 and an ITO heater showed low power consumption and a stable driving voltage when the PLZT was held at 100°C by the heater.
VCO Resonators Using ZnO Sputtered Film
Authors: Fujishima Satoru , Kasanami Toru , Nakamura Takeshi , Nishiyama Hiroshi
Published: March 2014

Unique, adjustment-free VCO oscillators for FM stereo demodulators have been developed by using ZnO piezoelectric thin films. The reactive sputtering method is employed for the deposition of ZnO thin film transducers onto tuning-bar resonators which are photolithographically fabricated from an ELINVAR alloy metal plate.
These oscillators encapsulated in SIP type resin packages (2.5T×6W×8L mm) operate at 76 kHz, and are found to be practical and useful because of their superior features. Excellent performance characteristics are obtained from the FM multiplexer using this oscillator.
Internal Electrode Piezoelectric Ceramic Actuator
Authors: Takahashi Sadayuki , Ochi Atsushi , Yonezawa Masatomo , Yano Takeshi , Hamatsuki Takeshige , Fukui Izumu
Published: March 2014

An internal electrode multilayer piezoelectric ceramic actuator element has been investigated. An individual internal electrode has the same area as the element cross section area. It has no piezoelectric inactive part, so that it shows strain/field characteristics similar to plain piezoelectric ceramics. It can be driven by a relatively low voltage (200 V) and has a semipermanent life under a successive voltage pulse application. Typical properties of the element using 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 ceramics are 8.7×10-4 strain, over 3.5×107 N/m2 stress and within 100 µsec response time driven by 1×106 V/m field.
Excitation of Coupled Length-Expansion-Mode in a Piezoelectric Rectangular Plate by Using Interdigital Electrodes
Authors: Hirose Seiji , Yokoyama Tomoo , Shmizu Hiroshi
Published: March 2014

This paper presents an improved design of piezoelectric length-expansion-mode resonators which use interdigital electrodes both for poling treatment and for excitation of vibrations. It is found that the utilization of the piezoelectric coupling k
31 rather than k
33 by forming the interdigital electrodes in parallel to the length is more favorable for both high electromechanical coupling and low electric impedance. From studies on coupled-mode behaviors of the resonator, it is concluded that efficient excitation of the length-expansion mode and remarkable suppression of spurious modes can be achieved even in a large-width resonator.
Ferroelectric Films Deposited by Reactive Sputtering and Their Properties
Authors: Fukami Tatsuo , Sakuma Toshiyuki , Tokunaga Kazuo , Tsuchiya Hidetoshi
Published: March 2014

Thin films of ferroelectric materials (PZT and PLZT) have been deposited by dc reactive co-sputtering from composite metal target. Although the structure of the resulting films without substrate heating was proved as amorphous through X-ray diffraction, it can be changed to provide a desired perovskite structure by subsequent heat-treatment in a lead-compensated atomosphere. Some of the films, after poling in the planar direction, showed an obvious piezoelectric activity.
The Low Wave-Number Response of Raman Spectra from Amorphous PbTiO3
Authors: Takashige Masaaki , Nakamura Terutaro
Published: March 2014

The Raman spectra from amorphous PbTiO3 and from crystallized materials have been analysed by numerical computations based upon a damped harmonic oscillator model. The low wave-number response characteristic of the amorphous state can be well fitted by the two damped-oscillators analysis.
Preparation of Glasses and Ceramics for Electrical Use based on Alkoxide and Unidirectional Solidification Methods
Authors: Sakka Sumio , Kokubo Tadashi
Published: March 2014

A review has been made on two methods of preparing glasses and ceramics: (1) alkoxide method for preparing oxide coating films and (2) unidirectional solidification of melts for preparing oriented oxide crystalline bodies. In the alkoxide method for coating, the substrate is dipped in the metal alkoxide solution, withdrawn and heated to several hundred degrees Celsius. Formation of SiO2 and BaTiO3 films has been described in detail. In the unidirectional solidification the melt is cooled down in the presence of temperature gradient. Formation of unidirectional crystalline bodies of 0.7NaNbO3·0.3BaTiO3, γ-6Bi2O3·SiO2, PbTiO3 and Bi2PbNb2O9 has been introduced in detail.
Effects of MnO Additive on Piezoelectric Properties in Modified (Pb, Ca)TiO3 Ferroelectric Ceramics
Authors: Yamashita Youhachi , Yoshida Seiichi , Takahashi Takashi
Published: March 2014

Effects of MnO additive concentration and poling field dependence on the properties in (Pb0.76Ca0.24) ((Co1/2W1/2)0.04Ti0.96)O3 ceramic material were investigated. A small amount of MnO additive, up to 1.0 mol%, increases electrical resistivity for the ceramic and facilitates the poling procedure. Electromechanical coupling factor thickness mode Kt increases with increasing poling field and exhibits Kt=0.53, while coupling factor planar mode Kp decreases to a negligibly small value of Kp≃0 over 45 kV/cm at 100°C. This phenomenon is probably due to 90° domain rotation of the ceramic caused by strong poling field.
Pyroelectric Properties of Grain-Oriented Bismuth Layer-Structured Ferroelectric Ceramics
Authors: Takenaka Tadashi , Sakata Koichiro
Published: March 2014

Pyroelectric properties of bismuth layer-structured ferroelectrics (BLSF) were studied on their grain-oriented ceramics prepared by the hot-forging (H.F.) method, as compared with ordinarily fired (O.F.) ones. The pyroelectric coefficient p was automatically measured and three figures of merit were calculated. Pyroelectric measurements using a chopped laser beam light gave the voltage responsivity R
v and the detectivity D
* as a function of the chopping frequency. Figures of merit of H.F. ceramics are two times as large as those of O.F. ones. The H.F. ceramics have indicated the grain orientation effects on their pyroelectric properties.
Effect of Substitution in Perovskite-type Oxide Superconductor
Authors: Suzuki Minoru , Murakami Toshiaki
Published: March 2014

Several kinds of ions were substituted into perovskite-type BaPb1-x
Bi
x
O3 (BPB), and the changes thereby brought about in electrical and superconducting properties have been studied. For B site substitution, only Bi is effective to bring about superconductivity with T
c above 3 K. Meanwhile, Cs, Rb and Sr were substituted into A site. These resulted in a reduction in lattice constants, accompanied by a decrease in T
c, when the substitution amount exceeded about 10% of A site ions.
Liquid-Phase-Sintering of Barium Titanate and Its Modified Ceramics with Addition of Pb5Ge3O11
Authors: Adachi Masatoshi , Nishibe Naomi , Shiosaki Tadashi , Kawabata Akira
Published: March 2014

The liquid-phase-sintering effect has been examined in preparing BaTiO3 (BT) and its related ceramics. Lead germanate Pb5Ge3O11 (PG) was used as a bonding-phase material because of its low melting point. The dielectric constant 1230 and loss tangent 0.019 were obtained in BT-PG composite ceramics added with 10 wt% PG. The BT-BTS (Ba(Ti, Sn)O3)-PG composites, including in homogeneous two-phase, are obviously promising for improving the temperature characteristics of dielectric composite ceramics.
Characteristics of a SrTiO3-Base BL Capacitor with Nb2O5 and CuO Added
Authors: Yamaoka Nobutatsu , Murase Kiyoshi , Tsunoda Shuichi
Published: March 2014

Characteristics of BL capacitors of semiconductive SrTiO3-base composition with Nb2O5 and CuO added were investigated. The grain growth was required for getting a high apparent dielectric constant under the firing condition in which a liquid phase appeared, and the ceramics with large grains such as 85 µm were fabricated. The apparent dielectric constant of 100,000 and the dissipation factor of less than 0.01 were obtained.
Dielectric Properties of Ceramics in the Ba(Zn1/3Nb2/3)O3- Sr(Zn1/3Nb2/3)O3 Solid Solutions
Authors: Nomura Shoichiro , Toyama Keiichiro , Kaneta Kumiko
Published: March 2014

Solid solution ceramics in the Ba(Zn1/3Nb2/3)O3-Sr(Zn1/3Nb2/3)O3 system have been studied in view of finding materials for use as dielectric resonators at microwave frequency. The relative dielectric constant of Ba(Zn1/3Nb2/3)O3 and Sr(Zn1/3Nb2/3)O3 ceramics is 41 and 40, and the unloaded Q is 7500 and 4000 at 9 GHz respectively. A nearly zero temperature coefficient of resonant frequency is obtained for a solid solution ceramic with 0.35 BZN-0.65 SZN. The temperature dependence of dielectric constant is discussed in terms of the Clausius-Mossotti relation.
Studies on Ultrasonic Welding with Two Vibration Systems
Authors: Tsujino Jiromaru , Ueoka Tetsugi
Published: March 2014

Ultrasonic welding with two different frequency vibration systems is proposed, and is shown to be very effective in the successful welding of various metal specimens. The cross angle between upper and lower welding tip vibration directions is 90 degrees. The vibration frequencies of upper and lower vibration systems used are 27 kHz and 20 kHz. The weld strength and weld area of the specimen joined by the two vibration systems are larger and more uniform than that done by conventional welding equipment with one vibration system. Static pressure distributions of weldment of 1 to 10 mm thick aluminium plates are measured to estimate the limit of ultrasonic spot welding.
Experimental Study of Ultrasonic Surgical Knife
Authors: Tsuda Yoneo , Mori Eiji , Ueha Sadayuki
Published: March 2014

Three ultrasonic surgical knives (resonant frequency, 20 kHz) were made on a trial basis and used for incision tests in order to study their cutting quality. The cutting quality of the knives remained sharp through the experiment at an amplitude of more than 30 µm. Bloodless surgery without damage to the peripheral tissue was also proved to be feasible at an amplitude a's high as 80 µm, if sufficient heat is generated by the friction loss of the knives. For easy handling, trial miniaturized ultrasonic knives (resonant frequency, 50 kHz) were also made.
An Air Backed Piezoelectric Ceramic Transducer with a Matching Layer of Metal
Authors: Shimomura Sumitake , Tanaka Heijirou
Published: March 2014

The effects of the thickness of a metal-made matching layer and electrical conjugate matching on the frequency sponse of air backed ceramic transducers are numerically examined. In application to the system of externally energizing an electronic apparatus implanted in the human body, this type transducer with a titanium layer about 0.4 mm thick is employed as a receiving transducer.
The power transfer function using these transducers is estimated theoretically and experimentally. At the maximum response, the power transmission efficiency is -6 dB or more.
Piezoelectric Properties of Ferroelectric PbTiO3 Solid Solutions
Authors: Takenaka Tadashi , Sakata Koichiro
Published: March 2014

Solid solution systems based on PbTiO3 were studied for their piezoelectric properties. The Pb(1-x)(BiLi)
x/2TiO3 (PBLT) system with high density (0.05<=x<=0.5) indicated that the Curie temperature T
c shifted higher as the concentration of (BiLi)1/2 (x) increased. The T
c at x=0.4 was about 590°C. These ceramics have dielectric constants of 130–170. In the Pb(1 -x-y)(BiLi)
x/2(NaCe)
y/2TiO3 (BLNC) system, (NaCe)1/2 (y) only a small quantity has been of interest in high temperature applications. The electromechanical coupling factors k
33 of the PBLT and the BLNC systems were about 17% and 28%, respectively.
Fracture Strength Evaluation of Piezoelectric Ceramics by Fracture Mechanics Parameter
Authors: Niitsuma Hiroaki , Chubachi Noriyoshi
Published: March 2014

A fracture mechanics approach to evaluate the flexural strength of commercially available piezoelectric ceramic plate has been proposed. A thickness dependence of flexural strength of the ceramic plate has been measured and discussed. Not only a representative flexural strength of the ceramic plate but also the thickness dependence can be accurately predicted using the parameter T
IC, which was proposed previously and is obtained by a combined procedure of fracture toughness testing and SEM observation of the largest pore size.
Analysis of Mechanism of Detecting Ultrasonic Wave in Magnetostrictive Sheet
Authors: Takeuchi Shinjiro , Takahashi Toyoki , Yoshimuta Kozo
Published: March 2014

This paper describes the mechanism of a detecting ultrasonic wave in a magnetostrictive sheet. Assuming an instantaneous equation with the changing of magnetostriction in the magnetostrictive sheet, an instantaneous waveform of output voltage can be deduced from the second derivative of this equation with respect to time.
Ultrasonic Transducer Made of Piezoelectric Polymer Film for Non-Destructive Inspection
Authors: Tomikawa Yoshiro , Ohki Masaki , Yamada Hiroaki , Onoe Morio
Published: March 2014

The purpose of this paper is to develop a new ultrasonic transducer for non-destructive inspection, and some experimental results on the transducer are presented. The result obtained is that the transducer can be fabricated easily and at low cost and, moreover, can radiate and detect a sharp ultrasonic pulse signal because of its wide frequency band characteristic. This transducer is expected to be one with high resolution capacity in non-destructive inspection.
VHF/UHF Composite Resonator on a Silicon Substrate
Authors: Kitayama Mikio , Fukuichi Tomohiro , Shiosaki Tadashi , Kawabata Akira
Published: March 2014

Thin film bulk wave resonators consisting of a piezoelectric film and a diaphragm made by anisotropic etching of silicon have been studied. A ZnO/SiO2 composite gives temperature coefficient of frequency of +7 to +45 ppm/°C. The sputter deposited SiO2 has given a Q-factor of 1250 and is more suitable for obtaining a high Q resonator than the thermal SiO2. Using a combination of the AlN film and p+
+Si, even a thick composite of several µm each which is reproducible and stable for a practical application has given a resonance frequency higher than 500 MHz.
Stoneley Waves Propagating along an Interface between Piezoelectric Material and Glass
Authors: Shimizu Yasutaka , Irino Toshio
Published: March 2014

In order to develop SAW devices without a package, we investigated Stoneley waves propagating along an interface between a piezoelectric material and an isotropic material. The existence conditions of Stoneley waves were obtained from numerical calculations. It was found that some of the actual glasses satisfy the condition for existence in ZnO/Glass structure but none of them do in LiNbO3/Glass.
Theoretical Analysis of Comb Transducers for Surface Acoustic Waves
Authors: Takeuchi Masao , Yamanouchi Kazuhiko
Published: March 2014

A comb transducer is one of the surface acoustic wave (SAW) transducers utilizing bulk-to-surface mode conversion, and is capable of exciting SAW's very efficiently on the surface of any test material for NDE applications. However, no thorough analysis of the transducer is available in the literature, and many problems on the mode conversion characteristics remain unexplained. In this paper, the operation of a typical comb transducer has been theoretically analyzed on the basis of the leaky wave concept and the coupled mode theory. The answers to such questions as the required appropriate coupling length between the comb coupler and a test substrate in relation to the mode conversion efficiency (MCE), the effect of liquid couplant thickness on the MCE, and the value of MCE expected to be obtained in theory are given.
Switching Properties of Optical Guided Waves in Multilayered Thin-Film Tunable Separators by Surface Acoustic Waves
Authors: Goto Nobuo , Miyazaki Yasumitsu , Akao Yasuo
Published: March 2014

Switching properties of optical guided waves in thin-film tunable separators due to acousto-optic effects were experimentally studied. The device consists of a ZnS/Ta2O5/Nb2O5 coupler on a Y-cut LiNbO3 substrate. Complete switching is possible for both phase-matched and phase-mismatched couplers. About 90% of incident light was switched in these two types of devices with the acoustic power of 0.75 W at 28.6 MHz and that of 0.50 W at 71.2 MHz, respectively.
Measurement of Low Frequency Adiabatic Compressibility of Liquids
Authors: Tanaka Hajime , Wada Yasaku
Published: March 2014

This paper describes a new apparatus for measuring adiabatic compressibility of liquids at 5 Hz to 2 kHz, which has a sensitivity much higher than a conventional unit and is applicable to a conductive liquid. The measurement of complex compressibility is also possible for a highly absorbing liquid.
Visualization of Ultrasonic Pulse in Glass by the Technique of Photoelasticity
Authors: Negishi Katsuo , Tsuboi Yukitoshi
Published: March 2014

A stroboscopic photoelastic system has been applied to visualize ultrasonic pulses propagating and reflecting in glass. It is revealed that the longitudinal-shear mode conversion caused by the reflection of ultrasonic wave at a free boundary of glass yields many spurious echo signals.
Ultrasonic Attenuation in the Magnetic Freeze-Out and Carrier Hopping Regions of n-InSb
Authors: Tokumoto Hiroshi , Mansfield Richard
Published: March 2014

Ultrasonic attenuation was measured on n-InSb with an excess donor concentration of 6.1×1013 cm-3 at low temperatures down to 0.3 K in magnetic fields up to 40 kG. In the magnetic freeze-out region, the attenuation exhibited a peak which shifted toward lower fields with decreasing temperature. On the other hand, the attenuation in the hopping region was quenched and the change with respect to magnetic field or temperature was much reduced. These results indicate that the attenuation is caused only by free electrons which can move so as to screen the electric fields associated with ultrasonic waves.
Dissipation of Energy in an N-Shape Formation Process for Single Sinusoidal Sound Wave
Authors: Nakamura Akira , Nakamura Toshiaki , Kajitani Kazuo
Published: March 2014

Energy dissipation of N wave compared with linear attenuation in a circular pipe is discussed. A single sound pulse of finite amplitude which is initially sinusoidal propagates into the pipe and its wave form is distorted by the nonlinear effects in addition to the linear absorption caused by the tube-wall effects. It is found in some cases that the total dissipation of energy included in whole wave shows lower attenuation than that of the small amplitude wave, despite its nonlinear distortion effect. It is concluded that this propagation behaviour appears for the waveform progressively distorted from a sinusoidal to an N wave, because the attenuation of energy is unaffected by the nonlinear dissipation before a shock front is formed.
Spectrum of Echo Scattered by Simple Object in Focused Sound Field
Authors: Ueda Mitsuhiro
Published: March 2014

A better understanding of the scattering process is essential to interpret images obtained by ultrasonic pulse echo systems. The scattering process in a plane or spherical sound field is well-known, but little is known about the scattering in a focused sound field. In this paper the spectrum of echo scattered by a simple object in a focused sound field is analyzed using the mathematical expressions of echo presented in earlier work. It becomes clear that frequency dependence of a spectrum changes by geometrical figure of scatterer as well as degree of focusing of the sound beam and some of the respects are verified experimentally.
Finite Element Simulation of Local Vibration of a Piezoelectric Plate Considering Energy Losses
Authors: Saiga Noriaki , Kajitani Kazuo , Suzuki Tatsuro
Published: March 2014

Local vibrations excited by a strip electrode of thickness-mode PZT plate are analyzed by finite element method including the effects of elastic, dielectric and piezoelectric relaxations. To estimate the mechanical Q and coupling factor of various modes, the equivalent circuit constants are derived. To find acoustic-energy concentration, the vibrational displacement profiles are investigated, depending on the parameters of mechanical Q and frequency.
A Technique for Measuring the Sound Velocity at Multi-Frequency Points within a Few Milliseconds
Authors: Nakajima Haruhiko , Kaneko Yasushi , Tanaka Kozo
Published: March 2014

Some techniques in measuring the sound velocity and attenuation constant in liquids are presented with emphasis on the unification of the pulse method and the resonant method. A true pulsed oscillator is proposed in which the phase of R.F. wave in a pulse has a definite relation to the oscillator enable signal. A high Q acoustic cavity which can be commonly used in both methods is described.
Automatic Vehicle Identification Using Pulsed Ultrasonic Radar
Authors: Iwamoto Kosaburo , Tanaka Kiyoshi , Futsuhara Koichi
Published: March 2014

In this paper the methods and results of measurements to classify vehicles travelling a roadway, without utilization of a vehicle-mounted device, are described. In this classification method, a shape pattern of the vehicle's height is measured using a pulsed ultrasonic radar sensor. This measured shape pattern is divided into 8 parts of equal length on a time base, and the height value of each of the 8 parts is compared with a table of values stored in advance in a microprocessor. When a pattern match is obtained, the vehicle class is identified. The passing vehicles are separated into four categories: 1) small passenger car, 2) large passenger car, 3) small truck and 4) large truck. This classification is independent of vehicle speed.
Photoacoustic Subsurface Imaging by Laser Beam Irradiation
Authors: Yatagai Toyohiko , Itoh Masahide , Hino Makoto , Takahashi Ichirou , Saito Hiroyoshi , Kim Pil Hyon , Namba Susumu
Published: March 2014

We have performed photoacoustic imaging of sub-surfaces in a metal using a microphone detection technique. A microcomputer controlled photoacoustic imaging system is developed. A sample in a sensitive photoacoustic cell is scanned mechanically and photoacoustic signals generated by a focused laser beam are detected with a condenser microphone, whose output a lock-in amplifier detects phase sensitively. The magnitude and the phase images of photoacoustic signal are displayed on a TV monitor. Clearer sub-surface structure images are obtained by digital image processing techniques.
Cationic Ring Opening polymerization of ε-caprolactam by a Montmorillonite Clay Catalyst
Authors: Kherroub Djamal Eddine , Belbachir Mohammed , Lamouri Saad
Published: March 2014

The ring opening bulk polymerization of ε-caprolactam catalyzed by Maghnite-H+ was reported. Maghnite-H+ is a montmorillonite silicate sheet clay was prepared through a straight forward proton exchange process. The effect of the amount of catalyst, and temperature was studied. Increasing Maghnite-H+ proportion and temperature produced the increase in ε-caprolactam conversion. The kinetics indicated that the polymerization rate is first order with respect to monomer concentration. Mechanism studies showed that monomer inserted into the growing chains with the acyl–oxygen bond scission rather than the break of alkyl–oxygen bond. © 2014 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Variation of the lunar highland surface roughness at baseline 0.15–100 km and the relationship to relative age
Authors: Yokota Y. , Gwinner K. , Oberst J. , Haruyama J. , Matsunaga T. , Morota T. , Noda H. , Araki H. , Ohtake M. , Yamamoto S. , Gläser P. , Ishihara Y. , Honda C. , Hirata N. , Demura H.
Published: March 2014

We report the surface roughness analysis of the lunar highlands for the baseline range 0.15–100 km. We use the Median Differential Slope αm to investigate the scale dependency of the roughness and derive the global αm distribution from SELENE Laser Altimeter and Terrain Camera data. While αm(l) versus baseline l (km) plots vary among different highland types, all highlands commonly show a peak at 3–30 km. The Pre‐Nectarian surface shows a relatively large αm(20–30 km). Our analysis is supported by the simulation of synthetic surface cratering models and crater statistics. In our simulation, a peak of αm(30 km) is successfully reproduced. The actual crater density shows good correlation with an empirical roughness indicator. However, a large part of the Nectarian surface shows a peak at 6–9 km baseline. This peak may be caused by secondary craters and ejecta deposit textures from the Nectarian system basins.
Modulation of galactic cosmic rays during the unusual solar minimum between cycles 23 and 24
Authors: Zhao L.‐L. , Qin G. , Zhang M. , Heber B.
Published: March 2014

During the recent solar minimum between cycles 23 and 24 (solar minimum P23/24), the intensity of galactic cosmic rays (GCR) measured at the Earth was the highest ever recorded since space age. It is the purpose of this paper to resolve the most plausible mechanism for this unusually high intensity. A GCR transport model in three‐dimensional heliosphere based on a simulation of Markov stochastic process is used to find the relation of cosmic ray modulation to various transport parameters, including solar wind (SW) speed, distance of heliospheric boundary, magnitude of interplanetary magnetic field (IMF) at the Earth, tilt angle of heliospheric current sheet, and values of parallel and perpendicular diffusion coefficients. We calculate GCR proton energy spectra at the Earth for the last three solar minima P21/22, P22/23, and P23/24, with the transport parameters obtained from observations. Besides weak IMF magnitude and slow SW speed, we find that a possible low magnetic turbulence, which increases the parallel diffusion and reduces the perpendicular diffusion in the polar direction, might be an additional possible mechanism for the high GCR intensity in the solar minimum P23/24.
Climate Change Is “a Defining Issue of Our Time,” Joint Report States
Authors: Showstack Randy
Published: March 2014

Noting that “climate change is one of the defining issues of our time,” a 26 February report jointly issued by the U.S. National Academy of Sciences (NAS) and the Royal Society in the United Kingdom aims to provide a clearly written reference document for policy makers, educators, and others about the current state of climate change science.
Science Fairs for Science Literacy
Authors: Mackey Katherine , Culbertson Timothy
Published: March 2014

Scientific discovery, technological revolutions, and complex global challenges are commonplace in the modern era. People are bombarded with news about climate change, pandemics, and genetically modified organisms, and scientific literacy has never been more important than in the present day. Yet only 29% of American adults have sufficient understanding to be able to read science stories reported in the popular press [Miller, 2010], and American students consistently rank below other nations in math and science [National Center for Education Statistics, 2012].
Advancing Geomicrobiology and Microbial Geochemistry
Authors: Druschel Gregory K. , Dick Gregory J.
Published: March 2014

By examining microbial and geochemical processes together, scientists have been able to gain a vastly clearer picture of how microorganisms shape their surrounding environment and vice versa. This was the central theme of a 2‐day workshop held in October 2013 in Chicago, Ill., that brought together 30 leading scientists from the rapidly growing field of geomicrobiology and microbial geochemistry (GMG).
Tectonic stress feedback loop explains U‐shaped glacial valleys
Authors: Schultz Colin
Published: March 2014

In the shadow of the Matterhorn, the broad form of the Matter Valley—like so many throughout the Alps—is interrupted by a deep U‐shaped glacial trough. Carved into a landscape reflecting millennia of tectonic uplift and river erosion, growing evidence suggests the 100‐meter‐deep U‐shaped groove was produced shortly after a shift toward major cycles of Alpine glaciation almost a million years ago. Subsequent glaciations may have therefore had little effect on the landscape.
Are Rare‐Earth Nanoparticles Suitable for In Vivo Applications?
Authors: Liu Chunyan , Hou Yi , Gao Mingyuan
Published: March 2014

Rare earth (RE) nanoparticles have attracted considerable attention due to their unique optical and magnetic properties associated with f‐electrons. The recent accomplishments in RE nanoparticle synthesis have aroused great interest of scientists to further explore their biomedical applications. This Research News summarizes recent achievements in controlled synthesis of magnetic and luminescent RE nanoparticles, surface modification, and toxicity studies of RE nanomaterials, and highlights state‐of‐the‐art in in vivo applications of RE nanoparticles.
Rhodium(III)‐Catalyzed Oxidative Olefination of Picolinamides: Convenient Synthesis of 3‐Alkenylpicolinamides
Authors: Zhou Jun , Li Bo , Qian Zhen‐Chao , Shi Bing‐Feng
Published: March 2014

A rhodium(III)‐catalyzed selective olefination of picolinamide derivatives has been developed. The reaction shows high regioselectivity, low catalyst loading (0.5 mol%), high yield and good functional group tolerance, providing a convenient strategy for the synthesis of 3‐alkenylpicolinamides.

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Hydrosilylation of Aldehydes and Ketones Catalyzed by Half‐Sandwich Manganese(I) N‐Heterocyclic Carbene Complexes
Authors: Zheng Jianxia , Elangovan Saravanakumar , Valyaev Dmitry A. , Brousses Rémy , César Vincent , Sortais Jean‐Baptiste , Darcel Christophe , Lugan Noël , Lavigne Guy
Published: March 2014

Easily available manganese(I) N‐heterocyclic carbene (NHC) complexes, Cp(CO)2Mn(NHC), obtained in one step from industrially produced cymantrene, were evaluated as pre‐catalysts in the hydrosilylation of carbonyl compounds under UV irradiation. Complexes with NHC ligands incorporating at least one mesityl group led to the most active and selective catalytic systems. A variety of aldehydes (13 examples) and ketones (11 examples) were efficiently reduced under mild conditions [Cp(CO)2Mn(IMes) (1 mol%), Ph2SiH2 (1.5 equiv.), hν (350 nm), toluene, 25 °C, 1–24 h] with good functional group tolerance.

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A General Synthesis of α‐Trifluoromethylstyrenes through Palladium‐Catalyzed Cross‐Couplings with 1,1,1‐Trifluoroacetone Tosylhydrazone
Authors: Jiménez‐Aquino Agustín , Vega Juan A. , Trabanco Andrés A. , Valdés Carlos
Published: March 2014

1,1,1‐Trifluoroacetone tosylhydrazone is presented as a very convenient substrate for the palladium‐catalyzed cross‐coupling with aryl halides. Under the proper reaction conditions, 3,3,3‐trifluoromethylstyrenes – very valuable trifluoromethylated synthetic intermediates – are obtained with high yields. The reaction features a very wide scope, as the presence of most functional groups is tolerated. Moreover, the reaction has been extended to substituted trifluoromethylstyrenes by employing substituted tosylhydrazones derived from other trifluoromethyl ketones.

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A Synthetic Route to Human Insulin Using Isoacyl Peptides
Authors: Liu Fa , Luo Ethan Y. , Flora David B. , Mezo Adam R.
Published: March 2014

The chemical synthesis of insulin has been a longstanding challenge, mainly because of the notorious hydrophobicity of the A chain and the complicated topology of this 51‐mer peptide hormone consisting of two chains and three disulfide bonds. Reported herein is a new synthetic route utilizing the isoacyl peptide approach to address the hydrophobicity problems. The incorporation of isoacyl dipeptide segments into both A and B chains greatly improved their preparation and purification, and the RP‐HPLC recovery of the chain ligation intermediates. The new route affords human insulin with a yield of 68 % based on the starting purified A chain and an overall yield of 24 % based on the substitution of the resin used for the preparation of A chain. To the best of our knowledge, this represents the most efficient route of human insulin chemical synthesis reported to date.
The Potent Oxidant Anticancer Activity of Organoiridium Catalysts
Authors: Liu Zhe , Romero‐Canelón Isolda , Qamar Bushra , Hearn Jessica M. , Habtemariam Abraha , Barry Nicolas P. E. , Pizarro Ana M. , Clarkson Guy J. , Sadler Peter J.
Published: March 2014

Platinum complexes are the most widely used anticancer drugs; however, new generations of agents are needed. The organoiridium(III) complex [(η5‐Cpxbiph)Ir(phpy)(Cl)] (1‐Cl), which contains π‐bonded biphenyltetramethylcyclopentadienyl (Cpxbiph) and C^N‐chelated phenylpyridine (phpy) ligands, undergoes rapid hydrolysis of the chlorido ligand. In contrast, the pyridine complex [(η5‐Cpxbiph)Ir(phpy)(py)]+ (1‐py) aquates slowly, and is more potent (in nanomolar amounts) than both 1‐Cl and cisplatin towards a wide range of cancer cells. The pyridine ligand protects 1‐py from rapid reaction with intracellular glutathione. The high potency of 1‐py correlates with its ability to increase substantially the level of reactive oxygen species (ROS) in cancer cells. The unprecedented ability of these iridium complexes to generate H2O2 by catalytic hydride transfer from the coenzyme NADH to oxygen is demonstrated. Such organoiridium complexes are promising as a new generation of anticancer drugs for effective oxidant therapy.
Molecular CuII‐O‐CuII Complexes: Still Waters Run Deep
Authors: Haack Peter , Limberg Christian
Published: March 2014

Research on O2 activation at ligated CuI is fueled by its biological relevance and the quest for efficient oxidation catalysts. A rarely observed reaction is the formation of a CuII‐O‐CuII species, which is more special than it appears at first sight: a single oxo ligand between two CuII centers experiences considerable electron density, and this makes the corresponding complexes reactive and difficult to access. Hence, only a small number of these compounds have been synthesized and characterized unequivocally to date, and as biological relevance was not apparent, they remained unappreciated. However, recently they moved into the spotlight, when CuII‐O‐CuII cores were proposed as the active species in the challenging oxidation of methane to methanol at the surface of a Cu‐grafted zeolite and in the active center of the copper enzyme particulate methane monooxygenase. This Minireview provides an overview of these systems with a special focus on their reactivity and spectroscopic features.
Syntheses and Structures of Terminal Arylalumylene Complexes
Authors: Nagata Koichi , Agou Tomohiro , Tokitoh Norihiro
Published: March 2014

Terminal arylalumylene complexes of platinum [Ar‐Al‐Pt(PCy3)2] (Ar=2,6‐[CH(SiMe3)2]2C6H3 (Bbp) or 2,6‐[CH(SiMe3)2]2‐4‐(tBu)C6H2 (Tbb)) have been synthesized either by the reaction of a dialumene–benzene adduct with [Pt(PCy3)2], or by the reduction of 1,2‐dibromodialumanes Ar(Br)Al‐Al(Br)Ar in the presence of [Pt(PCy3)2]. X‐Ray crystallographic analysis reveals that the AlPt bond lengths of these arylalumylene complexes are shorter than the previously reported shortest AlPt distance. DFT calculations suggest that the AlPt bonds in the arylalumylene complexes have a significantly high electrostatic character.
Synthesis, characterization and catalytic activity of Pd(II) complexes with N‐allyl functionalized imidazol‐2‐ylidenes in Suzuki–Miyaura reaction
Authors: Gümüşada Rukiye , Özdemir Namık , Günay M. Emin , Dinçer Muharrem , Soylu Mustafa Serkan , Çetinkaya Bekir
Published: March 2014

A series of Pd–N‐heterocyclic carbene (Pd–NHC) complexes were synthesized and characterized by elemental analysis and spectroscopic methods. In addition, the molecular structures of 3c and 4c were determined by X‐ray diffraction studies. Finally, the performance of complexes 3 and 5 were studied on Suzuki–Miyaura reactions of phenylboronic acid with aryl bromides. Copyright © 2014 John Wiley & Sons, Ltd.
Highly efficient in situ toughening of epoxy thermosets with reactive hyperbranched polyurethane
Authors: Tang Bing , Liu Xiaobing , Zhao Xiuli , Zhang Junhua
Published: March 2014

Hyperbranched polyurethane (HBPU), with low‐molecular‐weight polyethylene glycol space segments between the branching points, was synthesized by a pseudo one‐pot procedure. HBPU was characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and gel permeation chromatography. The HBPU was used as a modifier of diglycidyl ether of bisphenol A (DGEBA)/anhydride system. The rheological properties of HBPU‐G3/DGEBA blends were investigated by rotational rheometer. A slight decrease in viscosity of modified blends was observed by adding low content of HBPU and there was chemical reaction between HBPU and epoxy resin even without a hardener. The mechanical and thermal properties of the HBPU‐G3/DGEBA thermosets were characterized and compared with that of the neat epoxy thermosets. Their impact fracture surfaces were investigated by scanning electron microscopy, and the results indicated that no phase separation occurred in the DGEBA/anhydride system after the introduction of HBPU, which was confirmed by dynamic mechanical analysis and thermogravimetric analysis. After addition of 10 wt % HBPU, the toughness of the modified thermosets was found to be significantly improved without sacrificing their processability and thermal and mechanical properties to a large extent. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40614.
Effect of Oral Glucosamine on Joint Structure in Individuals With Chronic Knee Pain: A Randomized, Placebo‐Controlled Clinical Trial
Authors: Kwoh C. Kent , Roemer Frank W. , Hannon Michael J. , Moore Carolyn E. , Jakicic John M. , Guermazi Ali , Green Stephanie M. , Evans Rhobert W. , Boudreau Robert
Published: March 2014

Objective

To determine the short‐term efficacy of oral glucosamine supplementation by evaluating structural lesions in the knee joints, as assessed using 3T magnetic resonance imaging (MRI).

Methods

This study was designed as a randomized, double‐blind, placebo‐controlled trial. Recruitment was performed via mass mailings and an arthritis registry in southwestern Pennsylvania. In total, 201 participants with mild‐to‐moderate pain in one or both knees, as defined by a Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score ≥25 and ≤100, were enrolled. Of these subjects, 69.2% had a Kellgren/Lawrence grade ≥2 in at least 1 knee. Participants received 24 weeks of treatment with 1,500 mg glucosamine hydrochloride in beverage form or a placebo beverage. The primary outcome was decreased worsening of cartilage damage on 3T MRI of both knees, assessed according to a validated scoring system, the Whole‐Organ MRI Score (WORMS). Secondary outcomes included change in bone marrow lesion (BML) scores in all knees and change in excretion of urinary C‐terminal crosslinking telopeptide of type II collagen (CTX‐II).

Results

The adjusted odds ratio (OR) for the likelihood of decreased cartilage damage over 24 weeks in any WORMS‐scored subregion of the knee in the glucosamine treatment group compared to the control group was 0.938 (95% confidence interval [95% CI] 0.528, 1.666). Compared to subjects treated with glucosamine, control subjects showed more improvement in BMLs (adjusted OR 0.537, 95% CI 0.291, 0.990) but no difference in worsening BMLs (adjusted OR 0.691, 95% CI 0.410, 1.166) over 24 weeks. There was no indication that treatment with glucosamine decreased the excretion of urinary CTX‐II (β = −0.10, 95% CI −0.21, 0.002).

Conclusion

The results of this short‐term study provide no evidence of structural benefits (i.e., improvements in MRI morphologic features or urinary CTX‐II excretion) from glucosamine supplementation in individuals with chronic knee pain.
A Carbohydrate–Anion Recognition System in Aprotic Solvents
Authors: Ren Bo , Dong Hai , Ramström Olof
Published: March 2014

A carbohydrate–anion recognition system in nonpolar solvents is reported, in which complexes form at the B‐faces of β‐D‐pyranosides with H1‐, H3‐, and H5‐cis patterns similar to carbohydrate–π interactions. The complexation effect was evaluated for a range of carbohydrate structures; it resulted in either 1:1 carbohydrate–anion complexes, or 1:2 complex formation depending on the protection pattern of the carbohydrate. The interaction was also evaluated with different anions and solvents. In both cases it resulted in significant binding differences. The results indicate that complexation originates from van der Waals interactions or weak CH⋅⋅⋅A− hydrogen bonds between the binding partners and is related to electron‐withdrawing groups of the carbohydrates as well as increased hydrogen‐bond‐accepting capability of the anions.
Rapid Determination of the Amino Acid Configuration of Xenotetrapeptide
Authors: Kegler Carsten , Nollmann Friederike I. , Ahrendt Tilman , Fleischhacker Florian , Bode Edna , Bode Helge B.
Published: March 2014

An E. coli strain with deletions in five transaminases (ΔaspC ΔilvE ΔtyrB ΔavtA ΔybfQ) was constructed to be unable to degrade several amino acids. This strain was used as an expression host for the analysis of the amino acid configuration of nonribosomally synthesized peptides, including the novel peptide “xenotetrapeptide” from Xenorhabdus nematophila, by using a combination of labeling experiments and mass spectrometry. Additionally, the number of D‐amino acids in the produced peptide was assigned following simple cultivation of the expression strain in D2O.
Biological Evaluation of Multivalent Lewis X–MGL‐1 Interactions
Authors: Eriksson Magdalena , Serna Sonia , Maglinao Maha , Schlegel Mark K. , Seeberger Peter H. , Reichardt Niels‐Christian , Lepenies Bernd
Published: March 2014

Myeloid C‐type lectin receptors (CLRs) expressed by antigen‐presenting cells are pattern‐recognition receptors involved in the recognition of pathogens as well as of self‐antigens. The interaction of carbohydrate ligands with a CLR can trigger immune responses. Although several CLR ligands are known, there is limited insight into CLR targeting by carbohydrate ligands. The weak affinity of lectin–carbohydrate interactions often renders multivalent carbohydrate presentation necessary. Here, we have analyzed the impact of multivalent presentation of the trisaccharide Lewis X (LeX) epitope on its interaction with the CLR macrophage galactose‐type lectin‐1 (MGL‐1). Glycan arrays, including N‐glycan structures with terminal LeX, were prepared by enzymatic extension of immobilized synthetic core structures with two recombinant glycosyltransferases. Incubation of arrays with an MGL‐1‐hFc fusion protein showed up to tenfold increased binding to multiantennary N‐glycans displaying LeX structures, compared to monovalent LeX trisaccharide. Multivalent presentation of LeX on the model antigen ovalbumin (OVA) led to increased cytokine production in a dendritic cell /T cell coculture system. Furthermore, immunization of mice with LeX‐OVA conjugates modulated cytokine production and the humoral response, compared to OVA alone. This study provides insights into how multivalent carbohydrate–lectin interactions can be exploited to modulate immune responses.