Voltammetric behaviors of various globular proteins, including cytochrome c, ribonuclease A, lysozyme, albumin, myoglobin, and alpha-lactalbumin, were studied at the polarized 1,2-dichloroethane/water (DCE/W) interface in the presence of four different anionic surfactants, that is, dinonylnaphthalenesulfonate (DNNS), bis(2-ethylhexyl)sulfosuccinate (Aerosol-OT; AOT), bis(2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl)sulfosuccinate (BDFHS), and bis(2-ethylhexyl)phosphate (BEHP). When the W phase was acidic (pH = approximately 3.4), the surfactants (except for BEHP) added to DCE facilitated the adsorption of the above proteins to the DCE/W interface and gave a well-developed voltammetric wave due to the adsorption/desorption of the proteins. This voltammetric wave, which we here call "protein wave", is promising for direct label-free electrochemical detection of proteins. The current for the adsorption of a protein to the interface showed a linear dependence on the protein concentration in the presence of excess surfactant. The foot potential at which the protein wave appeared in cyclic voltammetry showed different values depending on the natures of the protein and surfactant. Multivariate analysis for the foot potentials determined for different proteins with different surfactants revealed that the protein selectivity should depend on the charged, polar, and nonpolar surface areas of a protein molecule. On the basis of these voltammetric studies, it was shown in principle that online electrochemical separation/determination of proteins could be performed using a two-step oil/water-type flow-cell system.

A flow system for electrochemical separation and detection of ions was constructed by connecting two oil/water (O/W)-type flow cells, in which a long polarizable O/W interface was formed at the inner surface of a porous poly(tetrafluoroethylene) (PTFE) tube. Using this system, acetylcholine and choline ions, whose ion-transfer potentials are different by only 60 mV, could be separated and determined simultaneously. It was thus shown that the present flow system is promising for the electrochemical flow separation/detection of ions and, in principle, also for electrochromatographic separation of ions.

In this paper, we present a summary of lightning protection measures aimed at securing a more reliable power supply for a telecom building.Based on an analysis of the entry paths of lightning surges into telecom building, we implemented lightning protection measures for the power receiving facilities by strengthening the equipment's tolerance to overvoltage surges. This was achieved by using a multistage lightning arrester (LA) to suppress the inflow and outflow of surges, and by introducing surge protective devices (SPDs) in the signal paths. To cover the eventuality of relay equipment damage caused by a lightning strike, we also implemented measures such as redundant undervoltage relays and potential equalization by connecting the earth electrodes together.Of these measures, this paper discusses an example of lightning countermeasures for relays that are at high risk from lightning strikes due to them being directly connected to signal lines from the outside, yet are responsible for important functions such as switching between the mains power supply and emergency backup generator. Since a relay's lightning surge breakdown voltage is relatively low, it can be impossible to protect with a commercial surge protector device (SPD). We therefore tried to suppress lightning surge voltages by using a lightning protection unit consisting of an SPD combined with an inductor. A relay has two types of wiring -the zero-phase voltage measurement line between the relay and the polemounted air switch (PAS) at the demarcation point between the commercial mains system and the customer equipment, and the -48 V DC control power supply lines between the rectifier and relay. These have two different earthing systems routed to the protective earth and to the -48 V DC earth wire, so we installed lightning protection units at both ports. To verify the effects, we measured the voltage applied to the electronic components inside the relay when a 10 kV lightning surge was applied to each port. As a result, we confirmed that these voltages were below the impulse breakdown voltage of the electronic components, and that the relay was able to continue operating normally.