Optical and electrochemical properties of all-solid-state transmittance-type electrochromic devices

Using a vacuum dry process, we constructed an all-solid-state transmittance-type electrochromic (EC) device consisting of five thin layers: ITO/IrO_x/Ta₂O₅/WO₃/ITO. We measured the optical and electrochemical properties of the EC device. By using Ta₂O₅ film as a proton conducting solid electrolyte, the device exhibited a fast response speed of 0.2 s and stable coloration characteristics. With an AC impedance method, we determined the properties of the device under varying temperature and environmental conditions. In the solid electrolyte (Ta₂O₅), the ion resistance controlled the response speed; the ionic conductivity and activation energy were 3 × 10^− 6 S/cm and 0.31 eV, respectively.     

Low firing and high dielectric constant X7R ceramic dielectric for multilayer capacitors based on relaxor and barium titanate composite

A temperature stable ceramic dielectric with a low firing temperature (1130 °C) and a high dielectric constant (3700 to 2600) has been developed by sintering the mixture of precalcined lead-based relaxor and prefired modified barium titanate.This dielectric was confirmed to be a two-phase ceramic composite body, according to X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy and dielectric measurements.A shortcoming of the high dissipation factor in the dielectric has been reduced by incorporating MnO into the barium titanate constituent prior to mixed sintering.This ceramic dielectric meets X7R specifications in the EIA (Electronic Industries Association) standard.     

An annular-ring microstrip antenna fed by a co-planar feed circuitfor mobile satellite communication use

A new configuration of circularly polarized annular-ring microstrip antenna (ARMSA) fed by a branch-line hybrid coupler placed at the inner part of the ARMSA and its design method using an equivalent circuit are presented. Since the ARMSA has a narrow bandwidth and high-input impedance, a parasitic element placed above the ARMSA is employed for not only obtaining a broadband characteristic, but decreasing the input impedance down to 50 Ω. A hybrid coupler to generate circular polarization, therefore, can be connected to the co-planar space of the ARMSA directly without a large-size matching circuit and a very low profile and simple structure can be achieved. The ARMSA is excited at the TM₂₁ mode to produce a conical pattern, which has a high gain in a low-elevation angle for mobile satellite communications. An effective design method using the equivalent circuit is indicated and, as a result, it is obvious that a broadband characteristic is obtained when each resonant frequency of the ARMSA and parasitic element is identical. Experimental results in the L-band showed satisfactory characteristics for vehicle antennas     

Optical input buffers for the HiPower photonic ATM switch-analysisand experiments

We describe an optical input buffer for the HiPower photonic ATM switch. This buffer can control the cell throughput in accordance with back pressure signals and incoming optical cells. We analyze the cell loss probability of the optical input buffer. Only a small buffer size of five is needed to obtain a cell loss probability of less than 10^-15 with 1024 ports. Experimental 10 Gb/s operation using optical fiber delay lines with gate control circuits shows that the bit error rate of the buffer is less than 10^-12     

An on-line method to monitor bwr core stability based on an autocorrelation method

An on-line monitoring method is introduced for BWR core stability. The method utilizes only autocorrelation values for two delay time intervals. Its simplicity makes it suitable for an on-line monitor. Accuracy of the core decay ratio calculated by the method improves as the core condition approaches instability. The error in the decay ratio for regional limit cycle oscillations is 0.2% when calculated from local signals in the most unstable region, and 4% when calculated from core averaged signals.     

LBA technique in the detection of chromosome variants. II. Chromosomes except for those with Q variants

In Part I of this communication, a technique (LBA) was described which used DNA replication in the evaluation of chromosome variants in man. It was shown that the method was very useful in the detection of variants in D- and G-group chromosomes. Results on pars 3 and 4 were also presented. In Part II, the rest of chromosomes were examined. In the evaluation of qh variants in 1, 9 and 16, the LBA technique proved itself to be a very effective implement. It was practically free of technical variables coherent with C-band technique and, therefore, it was possible to use the size of an euchromatic segment of a chromosome as a reference standard. LBA variants were observed in about 50% of the members of the remaining 12 pairs of chromosomes, i.e., 2, 5, 6, 7, 8, 10, 11, 12, 17, 18, 19, and 20.     

The grain size dependence of fracture toughness in an Al-6.0% Zn-2.5% Mg alloy

The grain size dependence of the fracture toughness (K _IC) of an aged Al-6.0% Zn-2.5% Mg alloy was studied experimentally. K _IC depended strongly upon grain size (L _G) in two ways. In the small grain size region K _IC decreased with increasing average grain size. In contrast, K _IC increased with increasing average grain size for large grain sizes. The increase in K _IC with increasing grain size arose as a result of the presence of abnormally large grains compared to the average grain size in the large-grained specimens.     

The strength of carbon fibre-reinforced nickel composites produced by electro-deposition and hot-pressing

Carbon fibre-nickel composites were made by electro-deposition and hot-pressing. The composites with low volume fraction of carbon fibres had a higher strength than the value obtained by the law of mixtures using the strength of annealed nickel. The current density became lower when the deposited nickel became thicker. The effects of annealing on deposited nickel were also observed and were related to the current density. Nickel deposited at low current density was hard to anneal.