Calix [n]arenes are a class of macrocycles that have attracted much interest because of their potential for forming host-guest complexes, and have been extensively investigated in various fields. In this study, in an attempt to develop calix[n]arenes as an effective analytical reagent with enzyme-like activity, the peroxidase-like activity of the ion-exchangers modified with some metal complexes of thiacalix[4]arenetetrasulfonate (Fig. 1) was investigated. The modified ion-exchanger with the highest activity was applied for the determination of hydrogen peroxide and glucose in place of peroxidase.
Cis-to-trans one way isomerization of stilbene in the first case catalyzed by proton, and then, secondly through electron transfer, occurred in acidic zaolites without light, suggesting that dimer cation radicals with charge transfer interaction between trans-stillbene and its cation radical may be formed in H-ZSM-5, whereas 1,4-dimer cation radicals of stilbene may be produced in H-mordenite.
This article presents the real-time strain measurement of a composite liquid hydrogen (LH 2 ) tank using fiber Bragg grating (FBG) sensors. The tank was composed of carbon fiber reinforced plastic (CFRP), and an aluminum liner was fabricated by the filament winding method and mounted on a reusable rocket. This rocket (vertical takeoff and landing) is called a reusable rocket vehicle test (RVT) and was developed by the Institute of Space and Astronautical Science of the Japan Aerospace Exploration Agency (ISAS/JAXA). Considering the high operational pressure and the iterative use of the tank, its structural integrity must be guaranteed. Thus, the authors have attempted a real-time strain measurement of the composite LH 2 tank using FBG sensors during rocket operations. First, the adhesive properties of the FBG sensors were investigated at cryogenic temperatures. As a result, UV-coated FBG sensors and polyurethane adhesives were adopted. An onboard FBG demodulator was then developed to be mounted on the rocket and its performance was assessed. Finally, the strain measurement was attempted during the flight experiments of the RVT using the onboard FBG demodulator. FBG sensors were glued on the surface of the composite LH 2 tank and connected to the onboard FBG demodulator. During these rocket operations, the output of the onboard FBG demodulator was continuously monitored via a telemetry system. The results obtained by the demodulator agreed well with those of the conventional foil strain gage.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.