Formation of Lead Zirconate-Lead Titanate Solid Solutions

Formation of the Pb(Zr,Ti)O₃ solid solution in the system PbO-TiO₂-ZrO₂ was studied by chemical analysis and X-ray powder diffrac-tometry. Only PbTiO₃ and Pb(Zr,Ti)O₃ were found as reaction products. The following three elementary reactions seemed to be reasonable for the formation of the Pb(Zr,Ti)O₃ phase: PbO + TiO₂→ PbTiO₃, PbTiO₃+ PbO + ZrO₂→Pb(Zr_1-λTi_λ)O₃, and Pb(Zr_l-λTi_λ)O₃+ PbTiO₃→ Pb(Zr_1-λ'Ti_λ')O₃ (λ<λ').     

Development of Reference Shunt for Short‐Time Alternating High Current Tests and Study of Measuring System

Short‐circuit tests for power circuit breakers and others require alternative short‐time current measurement, from a few kA to over several tens kA. However, the reference measurement system as a national standard or a specified secondary standard instrument to directly perform comparative test as a complete calibration test in high current class has not yet been established globally. The Japan Short‐Circuit Testing Committee (hereinafter referred to as “JSTC”) has therefore developed a shunt resistor that can be used as a standard instrument for high current measurement. Reference system using this shunt resistor is also considered by JSTC. The performance of the newly developed shunt resistor has been checked through several methods, such as resistance measurement, high power current test, high frequency current test, temperature rise test, and interference test. The results of the tests proved satisfactory performance. Resistance of the shunt resistor before and after the tests was invariant and stable. This makes the shunt resistor adequate for a reference in practical use. In addition, evaluation of uncertainty of the whole reference system including this shunt resistor satisfactorily fulfills the requirements of IEC 62475 edition 1.0, 2010.     

Switched-capacitor discrete Fourier analyser with window function circuit

An analogue window function circuit is realized by using switched-capacitor techniques. In order to verify the effect of this window, a novel switched-capacitor analogue discrete Fourier analyser is proposed. The window function circuit is included in this analyser as the ratios of capacitances. This switched-capacitor discrete Fourier analyser is very simple in construction, namely, only two elemental circuits based on the integral feedback capacitance circuit are connected in series. Agreement between the experimental and the theoretical values is confirmed.     

Novel Measurement of Hypoxanthine in Fish Using Direct Measurement Probe and Chemiluminescence Flow Injection Analysis

Direct measurements of hypoxanthine (Hx) in fish flesh were carried out using a sardine and a grunt twice with the same fish, and the average of 10 successive measurements (from 120 sec to 480 sec after pressing the probe against fish tissue) was taken as the Hx concentration by direct measurement. Results with two nearby tissues of one sample were 42.9 ± 4.9 μM and 42.6 ± 2.6 μM for the sardine, and 639 ± 33 μM and 598 ± 29 μM for the grunt. For sardine, Hx results from this direct method did not agree well with perchloric acid extraction measurements, but they were much better for grunt.     

ADSORPTION BEHAVIOR OF COBALT( II) IONS ON LAYERED DIHYDROGEN TETRATITANATE HYDRATE FIBERS IN AQUEOUS SOLUTIONS IN THE RANGE FROM 298 to 523 K

The adsorption properties of cobalt(II) ions have been studied on layered dihydrogen tetratitanate hydrate fibers, H₂Ti₄O₉,?nH₂O, in the temperature range from 298 to 523?K. The distribution coefficients of the adsorption of cobalt (II) ions were increased with increasing temperatures up to 367?K, but were decreased in the temperature range between 367 and 523?K. The X-ray powder diffraction patterns of the fibers indicate that the fibers hold layer structure up to 367?K, but change to low crystalline anatase or its precursor above that temperature. It is notable that the material has the capability of cobalt (II) adsorption even at 523?K, although the maximum is present at 367?K.     

ION-EXCHANGE PROPERTIES OF HYDROUS TITANIUM DIOXIDE WITH A FIBROUS FORM OBTAINED FROM POTASSIUM DITITANATE

ABSTRACT

Ion-exchange properties of a new type of hydrous titanium dioxide with a fibrous form, which was obtained from potassium dititanate (K₂O(TiO₂)2), have been studied. The pH titration curve snowed that this material behaved as a bifunctional ion-exchanger. Distribution coefficients of some divalent metal ions on this material were measured as a function of pH and the selectivity series were found to be Ba > Sr > Ca > Mg for alkaline earth metal ions and Cu > Zn > Mn > Co > Ni for divalent transition metal ions. Large separation factors were obtained between some metal ion pairs and the mutual separations such as Cu from Sr, Ca, Mg, Co and Ni, and Mg from Ba and Zn have been achieved on columns of this material.     

Nonlinear Electrical Properties of Grain Boundaries in an Oxygen-Ion Conductor (CeO2· Y2O3)

The ceria-yttria solid solution is a good anionic conductor. In polycrystalline ceramics, the complex impedance spectroscopy shows clearly the existence of a significant additional resistance associated with the grain boundaries. In this paper a theoretical analysis of the ac response in the nonlinear regime is developed. In particular the current-voltage and capacitance-voltage characteristics of the grain boundaries are derived. For the material investigated the former is well fitted by the Poole-Frenkel law while the capacitance is voltage independent. These results are in agreement with microscopic STEM observations of a silica-rich second phase.     

Changes of Aldehyde Levels in Defatted Soybean Extract

Aldehyde levels in defatted soybean extracts were measured by using aldehyde dehydrogenase. The level increased during incubation of flour-water suspension and its centrifuged extract at pH 6.5, while it decreased markedly at alkaline pHs. This aldehyde-eliminating activity was observed in 1:5 flour:water ratio, but was not in 1:20 flour:water ratio. ¹⁴C-labelled acetaldehyde added to 1:5 flour:water extract was converted into acetic acid. Fractionation of the extract indicated that a heat-labile protein and a heat-stable compound with low molecular weight were required for the aldehyde-eliminating activity.     

Mechanism of inactivation of heat-tolerant spores of Bacillus stearothermophilus IFO 12550 by Rapid Decompression

The effect of three rapid decompression methods to clear the mechanism of inactivation of heat tolerant spores of Bacillus stearothermophilus IFO 12550 was investigated. Pressurization of the spores at 200 MPa and 75°C for 60 min caused a kill of 10⁴ CFU/mL by the link-motion system but the nonrotational rod valve and E.G. seal methods gave a kill of about 10³ CFU/mL. Sterilization was due to the physical breakdown of spore coat, and was induced by its physical permeability of water at high pressure and temperature. Rapid decompression by the link-motion system at 200 MPa decreased the D-value of the spores from 3000 min (100°C, one atmosphere) to 6 min, 11 min, and 17 min at 95, 85, and 75°C, respectively.     

Switched-capacitor DFT and IDFT circuit

The switched-capacitor realization of the discrete Fourier transform (DFT) is treated in this paper as well as the inverse discrete Fourier transform (1DFT). The output of the DFT has a sinusoidal waveform including the amplitude and phase information of the required spectra. These spectra are given simultaneously and almost in real time. The output of the 1DFT is given merely by adding DFT outputs. Furthermore, the circuit configuration of this system-from input to DFT, from DFT to 1DFT, and from 1DFT to output-is a very simple configuration constructed by a non-recursive filter circuit.