Equations of state of matter from shock wave experiments

An interpretation of the shock wave Hugoniot relation is made by using the Mie-Grüneisen equation of state. Isothermal pressure-volume curves for various metals are calculated from the data of McQueen and Marsh and Al'tshuler et al. A linear relation between shock wave velocity us and particle velocity up is assumed, and the numerical integration is extended beyond the range of the experiments. Independent calculations are made by using either the Slater or the Dugdale-MacDonald formula. Results thus obtained do not differ appreciably. The result for iron is in good agreement with that obtained by Al'tshuler et al., who used an experimentally determined value of the Grüneisen ratio. The equations of state thus calculated are well approximated by the Murnaghan-Birch equation of state with the second-order coefficient ξ varying from −½ to ½. The use of the TFD model is not valid below 100 Mb. However, inspection of the results gives the impression that for some metal the P-p curve will approach the TFD curve at pressures higher than 100 Mb. The density and incompressibility of the earth's core are compared with those of iron. The general conclusion is that the density of the earth's core is about 1 to 1.5 g/cm^3 less than the density of iron at corresponding pressure and temperature. The difference in incompressibility is very small. Bullen's incompressibility-pressure hypothesis is tested on the basis of the result obtained here. The variation of the values of incompressibility among the metals studied here is too large even at the pressure of 4 Mb to support the hypothesis. A detailed inspection of the result for the in-compressibility obtained here, however, implies that it is still difficult to avoid the conclusion arrived at from the incompressibility-pressure hypothesis that the inner core is solid

Absence of spectral peaks in short-period oscillations from the Chilean Earthquake

On the occasion of the great Chilean earthquake of May 1960, various modes of free oscillations of the earth were observed: spheroidal oscillations of wave number n = 2 (period 53 min) to 38 (3.7 min) [Benioff et al., 1961; Ness et al., 1961; Alsop et al., 1961; Bogert, 1961] and torsional oscillations of n up to 24 (5.2 min) [Bolt and Marussi, 1962; Brune et al., 1961]. From a rather negative result that the shorter-period oscillations were not well observed, we try here to deduce some conclusions regarding the earth's upper mantle structure or the oscillation mechanism of the earthquake. The result may be due to horizontal inhomogeneities of the upper mantle of the earth making the resolution of spectral peaks in shorter-period oscillations difficult, or it may be due to weak excitation of shorter-period oscillations by the source

Thermal diffusivity measurement of rock-forming minerals from 300° to 1100°K

Measurement of thermal diffusivity, K, of fused silica, quartz, olivine, periclase, jadeite, garnet, spinel, corundum and alkali feldspar was made at 1‐atm pressure and over the temperature range from 300° to 1100°K. All the samples are of gem quality but of millimeter size. The Ångström method was slightly modified to be applicable to small samples. For all the minerals except feldspar 1/κ increases almost linearly with temperature up to 700°K, as expected from the theory of lattice conduction. Tightly packed minerals, such as periclase, spinel, and corundum, have a diffusivity 3 to 10 times as large as that of other minerals. At temperatures higher than 700°K, 1/κ decreases with temperature for some minerals. This decrease can be interpreted as being due to radiative heat transfer within the crystals, if the opacity of the minerals is in the range 6 to 20 cm^(−1). High‐temperature optical data are essential for a detailed discussion of the radiation effect

Spectrally Selective Emitters with Deep Rectangular Cavities Fabricated with Fast Atom Beam Etching

科研費報告書収録論文(課題番号:11555057・基盤研究(B)(2)・H11～H13/研究代表者:湯上, 浩雄/太陽熱光起電力による高温輻射-電力直接変換システムの開発

Estimation of Driver Inattention to Forward Objects Using Facial Direction with Application to Forward Collision Avoidance Systems

In forward collision avoidance systems, warnings may be provided more effectively if the underlying timing is set earlier than normal when the driver’s attention is not in the forward direction of the vehicle. In this regard, we determined the following driver characteristcs: (1) the amount of horizontal facial rotation needed to keep track of a moving object in the driver’s field of view increases significantly when the horizontal viewing angle of that target object exceeds 20 degrees, (2) when the driver’s face is oriented in the forward direction, the horizontal angle of facial rotation falls within 15 degrees, and (3) the reaction time to warning lengthens in accordance with the increase in the horizontal viewing angle. In the context of forward collision warning systems, we have determined the difference in the distribution of the driver’s horizontal facial rotation angle, for cases when the driver’ attention was and was not directed to objects in the forward direction of the vehicle. Furthermore, we have measured the reaction time to warning when the driver’s face was not directed forward. Last, our findings were successfully applied to issue the onset timing of a forward collision warning system