No abstract

Fine powder of hydrophobic high silica zeolite was solidified with silica sol in the void of a 0.2 mm thick ceramic fiber sheet fabricated into a honeycomb structure, typically with 3.2 mm pitch × 1.7 mm height. The honeycomb rotor of adsorbent was applied to the VOC abatement system operating with thermal swing adsorption. Dependence of the removal efficiency of VOC on various variables was investigated for a test honeycomb rotor of 300 mm in diameter. The following operating guide was recommended to reach high performance where more than 95% of VOC in the feed gas is removed:  superficial velocity of feed air = 2−4 m/s, flow rate ratio of process to regeneration zone = 5−15, relative humidity < 80%, and regeneration air temperature = 180 °C with rotation speed optimized. The optimal rotation speed of the honeycomb rotor was investigated closely, and the result was interpreted in terms of the heat capacity ratio between the honeycomb rotor and the regeneration air stream.

Higher-ordered structure motifs of nucleic acids, such as the G-quadruplex (G-4), mismatched and bulge structures, are significant research targets because these structures are involved in genetic control and diseases. Selective alkylation of these higher-order structures is challenging due to the chemical instability of the alkylating agent and side-reactions with the single- or double-strand DNA and RNA. We now report the reactive OFF-ON type alkylating agents, vinyl-quinazolinone (VQ) precursors with a sulfoxide, thiophenyl or thiomethyl group for the OFF-ON control of the vinyl reactivity. The stable VQ precursors conjugated with aminoacridine, which bind to the G-4 DNA, selectively reacted with a T base on the G-4 DNA in contrast to the single- and double-strand DNA. Additionally, the VQ precursor reacted with the T or U base in the AP-site, G-4 RNA and T-T mismatch structures. These VQ precursors would be a new candidate for the T or U specific alkylation in the higher-ordered structures of nucleic acids.

Some heat treatment of a LiNbO 3 plate induces domain inversion, thereby yielding a ferroelectric inversion layer. In such a piezoelectric plate with an inversion layer, even-order thickness-extensional modes as well as odd-order modes can be excited piezoelectrically. Therefore, the ultrasonic transducer using such a piezoelectric plate is expected to operate over a wide frequency range. In this paper it is shown that broadband ultrasonic transducers can be obtained at a certain thickness ratio of inversion layer to plate and that the transducer characteristics differ depending on whether the inversion layer is on the front side or on the backside. The broadband characteristics are experimentally demonstrated by fabricating transducers with 9 MHz or 75 MHz center frequency using 36° rotated Y-cut LiNbO 3 plates with a ferroelectric inversion layer.