Automatic restraint and visual detection of fatigue crack growth when applying an anti-fatigue smart paste to bolt holes

An anti-fatigue smart paste, which consists of fine alumina particles and silicone grease with low viscosity, was applied to a bolt hole (and its periphery in some cases) in a steel plate specimen, and the effects of the smart paste on automatic restraint and visual detection of fatigue crack growth were experimentally investigated through fatigue tests. Fractographic observations using a scanning electron microscope were also carried out. As a result, approximately 20～410% increase in failure life was produced by the wedge effect of the alumina particles in the smart paste. When the smart paste was applied, remarkable black colour developed in the white paste along the paths of crack growth, exceedingly facilitating the visual detection of the crack growth.     

Separation of aromatic components from light cycle oil by solvent extraction

To improve the versatility of light cycle oil (LCO), separation of aromatic compounds from LCO by solvent extraction was investigated. LCO was analyzed to identify 35 components: 19 aromatics and 16 alkanes. The batch liquid–liquid equilibrium extraction of LCO was performed using furfural, sulfolane, and methanol as extraction solvents. In each solvent, the aromatics present in LCO were selectively extracted relative to the alkanes. The separation selectivities of aromatics relative to alkanes were larger in sulfolane than in the other solvents. Among the aromatic components, di- and tricyclic compounds were selectively extracted relative to the monocyclic ones.     

Photocatalytic Synthesis of p-Anisaldehyde in a Mini Slurry-Bubble Reactor under Solar Light Irradiation

Dense photocatalyst slurry was employed for the synthesis of p-anisaldehyde under solar light irradiation. An Fe-modified rutile TiO ₂ (Fe-TiO _2, 34.5 m ²/g) photocatalyst was used as a visible-light-responsive photocatalyst. A conventional TiO ₂ (P25, 35 m ²/g) photocatalyst was also examined as a reference catalyst. XRD patterns and diffuse reflectance spectra showed that Fe-TiO ₂ consists of 100 % rutile phase and absorbs more visible light compared to P25, respectively. The catalyst powder was suspended in an ethyl acetate solution of p-methoxytoluene in the mini-reactor, with oxygen bubbling, under a solar simulator, visible light, and UV LEDs. p-anisaldehyde, as a reaction product, was analyzed by sampling using gas-chromatograph. Regardless of the light source, Fe-TiO ₂ always outperformed P25 in terms of both generation rates (GR) of p-anisaldehyde and energy requirements (ER). It was demonstrated that the highly dense Fe-TiO ₂ slurry was efficient for the synthesis under solar light owing to the small size of the reactor. The small amount of Pt and ZrO ₂ cocatalysts significantly enhanced the GR under solar light. By adopting a visible light responsive Fe-TiO ₂ photocatalyst, the mini slurry-bubble reactor under solar light achieved a high GR per catalyst mass (CM), which is one to two orders higher than that reported by most previous studies with high-power lamps.     

Route guidance by a car navigation system based on augmented reality

Car navigation systems play a prominent role in road traffic safety and traffic regulation. However, it is necessary to improve the route guidance of car navigation systems so that they accurately and quickly recognize small differences in location. Thus, to increase the ease of understanding and safety of car navigation systems, navigation systems based on augmented reality have been proposed for providing guidance at road intersections. We are currently developing a car navigation system based on augmented reality, called AR‐Navi. We investigated designs for the display of road intersection guidance that can be easily understood even when limited information is available and proposed a “best shot” display method that does not use moving images. In addition, we implemented a prototype system that includes these methods and conducted driving experiments on public roads to evaluate the ease of understanding and safety of AR‐Navi. Using the evaluation results, we confirmed that the ease of understanding and safety is similar in the case of AR‐Navi and CG‐Navi. We also clarified the characteristics of AR‐Navi. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(2): 43–54, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22278     

Optical manipulation of multiple stable states in photorefractive four-wave mixing

Abstract

We propose an approach to manipulate the convergence in multiple solutions of phase conjugate reflectivity in photorefractive four-wave mixing. Although a method forcibly adding a π-phase shift to an incident beam has been already proposed to control the reflectivity, some restrictions have been required in the boundary conditions for the successful operation. Here, we control the reflectivity with the boundary conditions in which the phase shift operation is ineffective by itself. In our method, the phase shift operation is combined with the procedure of turning an incident beam on and off. With a numerical analysis of four-wave mixing, we show that our new approach brings drastic change in the spatial distribution of the index grating and leads the phase conjugate reflectivity which was not manipulated previously.     

Theoretical study of the temperature dependent hydrogen storage capacity of Pd and Ti nanoparticles

A hybrid simulation was carried out using discrete variational (DV) Xα molecular orbital and molecular dynamics methods to examine the storage of hydrogen in metal nanoparticles. The calculation load was light and therefore could be performed quickly on a generic personal computer. The simulation investigates the electronic states of hydrogen on Pd and Ti nanoparticles. The hydrogen dissociation behavior on the metal surface was reproduced, and the calculated bonding orbitals of Pd and hydrogen are consistent with other reports. The diffusion coefficient of hydrogen inside the metal displays the same temperature dependence as the theoretical results. This simplified calculation, which produces results in agreement with experimental/theoretical values, could lead to improved simulation methods for hydrogen storage materials.     

Analysis of the Microstructure of Mg2Si Thermoelectric Devices

High-performance Mg₂Si thermoelectric devices have been obtained by spark plasma sintering of high-purity, pre-synthesized, all-molten Mg₂Si powder. We studied the effects of source powder particle size on thermoelectric performance. To improve the performance, further investigation of the microstructure of the devices is needed. In this work we studied the microstructure of grain boundaries and interfaces between electrodes and Mg₂Si sintered bodies to increase understanding of Mg₂Si thermoelectric devices.     

Evaluation of Two Anchor Plate Capacity Models for Maw Systems

The present paper examines the accuracy of two models used to predict the capacity of single square plate anchors used in multi-anchor wall (MAW) systems constructed in Japan. Measured anchor plate capacities from full-scale in situ load tests reported in the literature are compared to predicted values using the analytical model recommended in Japan. A modified anchor capacity model is proposed that preserves the general form of the PWRC equation, but introduces correction factors to improve accuracy. The correction factors are empirically-based and are selected by back-fitting measured loads to achieve a resistance bias mean equal to one and a low coefficient of variation (COV) in bias values. The results of a large number of small-scale anchor capacity tests carried out in pullout boxes were used to guide the selection of back-fitted parameters. The correction factors account for the influence of the confining pressure (anchor depth), the plate size and the anchor rod length on the anchor plate capacity. New N_c and N_q factors are also presented as part of the new model. The bias statistics for the two models comprise an important contribution to future reliability-based calibrations of the ultimate anchor capacity limit state for MAW systems in Japan.     

Synthesis of γ-Ga2O3-Al2O3 solid solutions by spray pyrolysis method

Synthesis of the γ-Ga₂O₃-Al₂O₃ solid solutions by spray pyrolysis was examined. Spherical particles were obtained using an aqueous solution of Al(NO₃)₃ and Ga(NO₃)₃ with HNO₃. For Ga-rich composition, γ-phase solid solutions were directly crystallized by the spray pyrolysis. For Al-rich composition, spray pyrolysis gave amorphous products unless a sufficient thermal energy was supplied during the spray pyrolysis. Subsequent calcination of the amorphous products gave γ-Ga₂O₃-Al₂O₃ solid solutions. However, physical properties of the solid solutions were affected by the spray pyrolysis conditions.     

Suppression of inducible nitric oxide synthase expression and amelioration of lipopolysaccharide-induced liver injury by polyphenolic compounds in Eucalyptus globulus leaf extract

Eucalyptus leaf extract (ELE) is rich in hydrolyzable tannins. We examined the effects of ELE and its constituents on lipopolysaccharide (LPS)-induced liver injury in mice. Mice fed a diet supplemented with 1% ELE were intraperitoneally administered LPS. Six hours later, the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were significantly lower in the ELE-supplemented mice than in the controls; LPS-induced hepatic inducible nitric oxide synthase (iNOS) expression was also suppressed. ELE lowered LPS-stimulated iNOS expression in cultured RAW 264.7 macrophages. Furthermore, the aglycones of hydrolyzable tannins, gallic acid (GA) and ellagic acid (EA), inhibited iNOS induction to a greater extent than did ELE (15-fold higher). When mice were fed a 1% GA or EA diet, the increase in the serum ALT and AST activities and hepatic iNOS expression in response to the LPS challenge were significantly attenuated. Thus, hydrolyzable tannins in ELE ameliorate LPS-induced liver injury.