Resonance EMAT system for acoustoelastic stress measurement in sheet metals

Copyright 1993 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Review of Scientific Instruments, 64(11), 3198-3205, 1993 and may be found at http://dx.doi.org/10.1063/1.114432

A New Extraction System for Extremely Low Level 14C in Meteorites.

第3回極域科学シンポジウム/第35回南極隕石シンポジウム 11月29日（木） 国立国語研究所 2階講

Leaky Lamb Wave Along VCR Magnetic Tapes

High recording density with the home-use digital VCRs requires the use of narrow tracks, short recording wavelength, and thin magnetic tapes. Knowledge of Young’s modulus of the tape is essential for the precise positioning of the tape on the rotating drums and then a stable tape-to-head interface. The magnetic tapes usually show different Young’s moduli for the machine direction (MD) and the transverse direction (TD) [1]. The anisotropy develops mainly in the base film of polyethylene terephthalate (PET) through the partial crystallization and the crystallite orientation alignment during the stretching process on the tapes [2], while the original PET sheet, from which the tapes are cut, shows much less anisotropy. This situation requires the determination of Young’s moduli for both MD and TD of the tape. The tapes on play are straightened by tensile loads, which should be controlled with Young’s modulus for the MD. Too much load may distort the recorded tracks or damage the tape. Besides, the vertical load is applied onto both edges of the running tape by the guiding rollers. Again, too much load may induce the tape buckling. Critical load is proportional to the Young’s modulus in the TD. Large moduli are desirable for both directions

Nonlinear resonance interaction of ultrasonic waves under applied stress

Copyright 1984 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics, 56(1), 235-237, 1984 and may be found at http://dx.doi.org/10.1063/1.33375

Synthesis and characterization of phenylethynylcarbonyl terminated novel thermosetting imide compound

Phenylethynyl terminated novel imide compound based on 1,3-bis(3-aminophenoxy)benzene (APB) and phenylethynyl trimellitic anhydride (PETA) were prepared. The curing behavior of phenylethynyl terminated imide compound was investigated by differential scanning calorimetry and Fourier transform infrared spectrometry. The curing reaction of phenylethynylcarbonyl end group completed at 220°C, and proceeded much faster than that of phenylethynyl end group. Glass transition temperature of the thermosetting resin from phenylethynylcarbonyl terminated novel imide compound determined by dynamic mechanical analysis was almost the same as that of o-cresolnovolac type epoxy resin. In addition, the thermosetting resin from phenylethynylcarbonyl terminated novel imide compound exhibited excellent thermal and dimensional stabilities. These excellent properties of these phenylethynyl terminated imide compound might be due to the incorporation of alkene group or aromatic ring substitutes in the backbones, which might enhance the chain interaction (molecular packing) and reduce the molecular chain mobility

Glasslike vs. crystalline thermal conductivity in carrier-tuned Ba8Ga16X30 clathrates (X = Ge, Sn)

The present controversy over the origin of glasslike thermal conductivity observed in certain crystalline materials is addressed by studies on single-crystal x-ray diffraction, thermal conductivity k(T) and specific heat Cp(T) of carrier-tuned Ba8Ga16X30 (X = Ge, Sn) clathrates. These crystals show radically different low-temperature k(T) behaviors depending on whether their charge carriers are electrons or holes, displaying the usual crystalline peak in the former case and an anomalous glasslike plateau in the latter. In contrast, Cp(T) above 4 K and the general structural properties are essentially insensitive to carrier tuning. We analyze these combined results within the framework of a Tunneling/Resonant/Rayleigh scatterings model, and conclude that the evolution from crystalline to glasslike k(T) is accompanied by an increase both in the effective density of tunnelling states and in the resonant scattering level, while neither one of these contributions can solely account for the observed changes in the full temperature range. This suggests that the most relevant factor which determines crystalline or glasslike behavior is the coupling strength between the guest vibrational modes and the frameworks with different charge carriers.Comment: 8 pages, 4 figures, 4 tables, submitted to Phys. Rev.

Preliminary examination of the Yamato-86032 lunar meteorite: II. Major and trace element chemistry

The chemical composition of the new lunar meteorite Yamato-86032 has been studied by several laboratories in a consortium study. A preliminary report on the first analytical results from seven laboratories is given in this paper. The meteorite, which is the largest lunar meteorite recovered so far, is more heavily shocked than the other five lunar meteorites, which makes it difficult to classify the rock exactly. Although it may be classified as an anorthositic breccia the trace element composition of Y-86032 is somewhat different from the composition of the other known lunar meteorites. The major element chemistry of Y-86032 is similar to the other lunar meteorites, except for the iron content, which is lower by a factor of about 1. 4. Since the magnesium abundance is nearly identical there is a disparity in the mg ratio. The REE abundances in Y-86032 are very low and comparable to Y-82192/3. There is no evidence of any KREEP component. The abundances of several lithophile and incompatible elements are lower in Y-86032 than in the other lunar meteorites. The siderophile element contents are low and vary between individual chips. Sc, Cr, Mn, and Co have significantly lower abundances than in Y-82192/3. The chemical investigations demonstrate that Y-86032 is a new and important sample from the lunar highlands