A High-Speed Measurement Method for Reflective Liquid Crystal Cells Using a Liquid Crystal Polarization-Converting Device

We propose a novel measurement method for determining cell parameters, such as a cell thickness and twist angle in reflective liquid crystal (LC) cells, by using a unique polarization-converting device prepared with a circularly and homogeneously aligned LC (CH-LC) cell. The light intensity distributions from the reflective LC cell transmitted twice through the CH-LC cell are measured by a charge-coupled device array camera. Cell thickness can be derived by using coordinate values of local minimum spot in the spatial light intensity distribution measured at one wavelength, where the pretilt angle is assumed to be the designed value. Both cell thickness and twist angle can also be determined by two local minimum positions of the light intensity at two different wavelengths and the effects of a quarter-wave plate are discussed     

A High-Power Low-Distortion GaAs HBT Power Amplifier for Mobile Terminals Used in Broadband Wireless Applications

This paper describes technologies of miniaturized high-power low-distortion GaAs HBT power amplifiers with a low-voltage operation for mobile terminals used in 5-6 GHz broadband wireless applications. In conjunction with diode-based linearizing techniques, wideband matching network techniques including trap circuits for second harmonics allow us to obtain a compact broadband power amplifier module with harmonic filtering, achieving the high linear output power at a low supply voltage together with the low distortion and the low second-harmonic spurious outputs in a wide frequency range. The fabricated power amplifier exhibited linear output power levels of 21 and 22 dBm at EVM values of 2.0 and 3.0%, respectively, measured with 54 Mb/s 64-QAM-OFDM signals at a supply voltage of 3.3 V in a frequency range of 5-6 GHz. Second harmonic spurious outputs below -35 dBc were also attained.     

Bubble behaviors in subcooled boiling of wetting surface under low gravity

Stainless steel plate with 30mm in length, 1 mm in width and 0.1 mm in thickness is employed for a heating surface in subcooled quasi-pool boiling of water under low gravity performed by a parabolic flight. Testing liquid subcooling is about 10K at atmospheric pressure. The wetting heating surfaces are coated with ceramics materials which have been developed by a certain glass company. DC power is applied directly into the test heating surface and the bubble behaviors are observed by a high-speed video camera. Contact angle of water droplet is about 77–96 degree for the stainless surface and 30 degree or less for the wetting surface. In the ground experiment, the size of detaching bubbles from the wetting surface is smaller than those of stainless surface and the detaching period is shorter at same heating power. The burnout heat fluxes of wetting surfaces are about 50 percent higher those of stainless surfaces. In the low gravity experiment, DC power is applied into the surface at 10 second before start of low gravity and increases slightly until burnout. A single large bubble grows on the stainless surface and finally, the surface is burned out in a short period. For wetting surface, several large coalescing bubbles appear and they move rapidly on the surface, then one of the large bubbles grows and the burnout occurs. The burnout heat fluxes are higher than those of stainless surface. The wetting ceramics surface is considered to accelerate the liquid supply and the bubble moving.     

FeCrNiAl alloy intended for using as blade material fabricated by rapid solidification method

We explored fabrication of ribbons of the FeCrNiAl alloy by rapid solidification method and succeeded in producing ribbons of 0.6 mm width and 30 m thickness. The obtained ribbon-shape product is prospective for usage as blade material. The as-solidified product, however, is too hard and brittle for the succeeding punching operation to be applied for a final-product shape. This was found to be due to existence of extremely fine particles of NiAl based B2 phase uniformly dispersed in the matrix. We, therefore, searched for a heat-treatment for improving ductility and found an appropriate one. By this heat-treatment ductility was improved to such an extent that the punching operation was applicable. We then searched for a heat-treatment for producing Al₂O₃ on the surface which facilitates a hard and sharp blade-edge, and found an appropriate one. This heat-treatment simultaneously hardens the matrix once softened to an extent sufficient for supporting the Al₂O₃ layers. The final product is suitable for applications as blades, such as razors.     

Dynamic and quasi-static behaviors of magneto-thermo-elastic stresses in a conducting infinite plate subjected to an arbitrary variation of magnetic field

Summary In the present paper, dynamic and quasi-static behaviors of magneto-thermo-elastic stresses in a conducting infinite plate subjected to an arbitrary variation of the magnetic field are investigated. It is assumed that a magnetic field defined by an arbitrary function of time acts on both side surfaces of the infinite plate in the direction parallel to its surfaces. Fundamental equations of one-dimensional electromagnetic, temperature and elastic fields are formulated. Then, solutions of magnetic field, eddy current, temperature change and both dynamic solutions and quasi-static ones of stresses and deformations in the infinite plate are derived analytically. The solutions of stresses are determined to be sums of thermal stress caused by eddy current loss and magnetic stress caused by Lorentz force. For the case that the arbitrary function is given by the sine function, the dynamic and quasi-static behaviors of the stresses are examined by numerical calculations.     

Fluorex reprocessing system for the thermal reactors cycle and future thermal/fast reactors (coexistence) cycle

A new reprocessing technology, FLUOREX was proposed for thermal reactors cycle and future thermal/fast reactors (coexistence) cycle. The proposed system is a hybrid system that combines fluoride volatility and solvent extraction methods. Spent fuel will be sheared and cladding material will be removed by dry oxidation/reduction method such as AIROX process. Fluorination and purification of most uranium can be easily achieved by fluoride volatility method with compact facility. About 10% residues including plutonium can be treated in well-established PUREX method, which means this facility load will be about 1/10 of the conventional PUREX facility with same capacity. Between fluorination process and PUREX process, there is a pyrohydrolysis process where the fluoride compounds from fluorination process are converted to the oxides. Pure mixture of Pu and U can be obtained by solvent extraction method without separating Pu and U, which is suitable for conventional MOX fuel fabrication. The system can recover pure U and MOX with the decontamination factor of over 10⁷ and can drastically reduce the cost and waste generation compared with the conventional one.

Semi engineering scale experiments for the fluorination, pyrohydrolysis, and dissolution of Pu containing materials were carried out. From those experimental results, key elemental processes were fundamentally proofed.     

Sol-gel transition of a mixture of gelatin and κ-carrageenan

Abstract

The characteristics of sol-gel transition of a mixture made by mixing two kinds of gelling agents of different nature, i.e. gelatin and carrageenan were examined. The sample solutions consisted of 3.00 wt % gelatin solution, 1.00 wt % κ-carrageenan solution and 4.00 wt% mixed solution which was prepared by mixing the said gelatin and carrageenan solutions in the ratio 3:1. In the experiment, the optical rotation and the dynamic viscoelasticity were measured under the same temperature change program. As the sample solutions were cooled, the carrageenan solution started to show a change in the specific rotation in the first place, followed by the mixed solution and finally the gelatin solution. The gelatin and the mixed solutions had the same increasing tendency in the specific rotation, whereas the carrageenan solution changed a little. When the mixed solution was chilled to set, it turned into a highly elastic gel. In the mixed solution, the gelation of carrageenan was found to precede that of gelatin.     

Strain analysis of arsenic-doped silicon using CBED rocking curves of low-order reflections

Local lattice strains of semiconductor devices have been so far examined using higher order Laue zone (HOLZ) line patterns of convergent-beam electron diffraction (CBED). Recently, strain analyses in highly strained regions near interfaces have been reported using split HOLZ line patterns. In the present paper, it is demonstrated for arsenic-doped silicon that the use of CBED rocking curves of low-order reflections provides a promising new tool for the determination of strain distributions of highly strained specimen areas. That is, the anomalous intensity increase in the CBED rocking curves of low-order reflections is explained using a model structure with a strain gradient in the electron beam direction, which is similar to the models used for the split HOLZ line patterns.