Porous Titania Ceramic Prepared by Mimicking Silicified Wood

A porous titania ceramic with a woodlike microstructure that was analogous to silicified wood was prepared. The production of "titanified wood" was performed using the following process: (i) introduction of titanium tetraisopropoxide into wood materials via vacuum infiltration, (ii) hydrolysis of the titanium tetraisopropoxide in the cell structure to form a titania gel, and (iii) firing at a temperature of 600°–1400°C in air. The resulting titania ceramic had the same external and internal forms of the original wood.     

Development of virtual and real-field construction management systems in innovative, intelligent field factory

In this study, we proposed a concept of virtual and real-field construction management systems (VR-Coms), which is integrated with virtual construction simulation, planning, scheduling, and performance management systems to evaluate productivity and safety in virtual simulated and real-field constructions. And, we built up a computational environment to develop the VR-Coms. The VR-Coms offer supporting modules for learning and discovering solutions with objective to manage construction at right speed with improved humanware and constructability. The configuration of VR-Coms is described. This paper also shows an application of agent theory to construction management.     

In vivo visual reporter system for detection of estrogen-like substances by transgenic medaka

Detection of endocrine disrupting chemicals, in particular, environmental estrogens with living organisms, has many advantages if compared to chemical analysis. The screening of novel pollutants with meaningful endpoints, the integration of uptake, bioconcentration, and excretion as well as the evaluation of endocrine disrupting effects with respect to toxicity require in vivo biotests for estrogen-like substances (ELSs). Critical disadvantages of whole organism biotests are their low sensitivity and the need for laborious and time-consuming work. To overcome these problems, we have developed a transgenic medaka strain harboring the green fluorescence protein (GFP) gene driven by choriogenin H gene regulatory elements. Choriogenin H is an egg envelope protein induced by estrogens in the liver. With yolk sac larvae of this strain, GFP induction in liver was observed 24 h after onset of aqueous exposure to 0.63 nM 17beta-estradiol (E2), 0.34 nM ethynylestradiol, or 14.8 nM estrone. Furthermore, concentrated sewage treatment effluent induced GFP expression. Comparison of E2 equivalents estimated by GFP-induction in transgenic medaka, a YES assay, and GC/MS showed detection limits in the same order of magnitude. These results indicated that the sensitivity of the transgenic medaka strain was sufficient for application as an alternative model in monitoring environmental water samples for ELSs.     

Quantitative bioimaging analysis of gonads in olvas-GFP/ST-II YI Medaka (transgenic Oryzias latipes) exposed to ethinylestradiol

This study investigates the adverse and persistent effects of ethinylestradiol (EE2) on mature gonads of transgenic olvas-GFPIST II-YI medaka (Oryzias latipes). The measurement of gonadal size calculating the GFP-fluorescent area was used as a technique that enabled monitoring gonads in living specimens by GFP fluorescence. First, mature medaka were exposed to EE2 (47.8-522 ng/L) for 4 weeks. The gonads showed a significant reduction of the GFP-fluorescent area and Gonadosomatic Index in males exposed to EE2 at >216 ng/L and females exposed at 522 ng/L. Histologically, males at all treatments exhibited testis-ova and additionally, high connective tissue prevalence at > or =216 ng/L. Next, mature male medaka were exposed to EE2 (43.7-473 ng/L) for 3 weeks and allowed to depurate for 6 weeks, to investigate persistent effects of EE2. Continuous gonad observation showed that GFP began to decline 3 weeks after initial exposure to > or =215 ng/L. After depuration, the gonad's fluorescent areas gradually recovered, with no statistical difference at the end of the depuration period; normal spermatogenesis was present in these individuals. Alterations in GFP fluorescence clearly indicate the condition of the gonad in transgenic medaka and this strain showed a facilitated screening fish model to detect the adverse effects on the gonad by estrogenic chemicals.     

Wideband and high-gain negative-feedback AGC amplifier for high-speed lightwave digital transmission systems

A negative-feedback AGC amplifier based on a new circuit configuration concept is proposed and monolithically integrated. The amplifier exhibits characteristics 2.5 times superior to those of the conventional AGC amplifier: 410 MHz bandwidth, 16 dB maximum gain and 18 dB gain dynamic range.     

Three-dimensional waveguide arrays for coupling between fiber-optic connectors and surface-mounted optoelectronic devices

This paper describes the fabrication of novel surface-mountable waveguide connectors and presents test results for them. To ensure more highly integrated and low-cost fabrication, we propose new three-dimensional (3-D) waveguide arrays that feature two-dimensionally integrated optical inputs/outputs and optical path redirection. A wafer-level stack and lamination process was used to fabricate the waveguide arrays. Vertical-cavity surface-emitting lasers (VCSELs) and photodiodes were directly mounted on the arrays and combined with mechanical transferable ferrule using active alignment. With the help of a flip-chip bonder, the waveguide connectors were mounted on a printed circuit board by solder bumps. Using mechanical transferable connectors, which can easily plug into the waveguide connectors, we obtained multi-gigabits-per-second transmission performance.     

Electromigration of sodium ions and electro-osmotic flow in water-saturated, compacted Na-montmorillonite

Sodium ions spiked with ²²Na as a tracer were migrated by electromigration and electro-osmosis in the water-saturated compacted Na-montmorillonite at dry densities 1.0×10³ kg m⁻³, under an electric potential gradient. Dissolved helium was also migrated by electro-osmosis in the montmorillonite. After migration, concentration profiles of the sodium ions and helium were obtained by γ-spectrometry and mass-spectrometric methods, respectively. From the profiles of both chemical species, not only migration due to electrokinetic phenomena but also mechanical dispersion was observed in the montmorillonite. The dispersion coefficients, D_i, and apparent migration rates, U_i^a, of ²²Na and helium were found in the compacted Na-montmorillonite at 1.0×10³ kg m⁻³. The migration of helium in the montmorillonite under an electric potential gradient reflects that of water because helium migrates as an electrically neutral species. The parameters D_He^m, U_He^a, and α_He correspond to those of water. The mechanical dispersion coefficients, D_Na^m, of ²²Na⁺ ions are much smaller than those of water obtained by helium. The dispersivity parameters, α_Na, for ²²Na⁺ obtained from these D_Na and U_Na^a values are 10⁻⁵ m and those for water (α_He) are 10⁻³ m. This indicates that ²²Na⁺ ions migrate in different spaces than water in the compacted montmorillonite under a potential gradient. This finding suggests that the migration of Na⁺ ions occurs in the interlayer and/or on the outer surfaces of the montmorillonite; whereas dissolved helium migrates in the pore water.     

Using artificial intelligence in communication system design

The authors describe a knowledge-based design support system, called KDSS, that will help designers inexperienced in communication system design easily create advanced systems like intelligent networks, and large-scale distributed computing systems. They began by designing a support system for protocol and communication software. They then experimented with applying expert-system technology in design support systems and developed an expert system for protocol synthesis called KSPS. An expert system for protocol and communication software design that is based on the earlier work is also part of KDSS