The effect of the molecular structure of a cationic azo dye on the photoinduced intercalation of phenol in a montmorillonite

The effect of the molecular structure of a cationic azo dye on the photoinduced intercalation of phenol into the azo dye-montmorillonites was reported. Two types of cationic azo dyes were used; one has (2-hydroxyethyl)dimethylammonium group (AZ(OH)⁺), and the other has trimethylammonium group (AZ(CH₃)⁺). Phenol was intercalated into both cation exchanged azo dye-montmorillonites (Kunipia F) by mechanical mixing without solvent. By the UV irradiation, the basal spacings increased further, and subsequent visible light irradiation led to decrease the basal spacings, indicating the intercalation and the deintercalation of phenol by the UV and visible light, respectively. The amounts of the phenol intercalated both chemically and photochemically varied depending on the azobenzene cations, showing the interactions between the cationic head group and phenol.     

Renewable resource based biocomposites from natural fiber and polyhydroxybutyrate-co-valerate (PHBV) bioplastic

Renewable resource based green biocomposites were prepared using a bacterial polyester i.e., poly(hydroxybutyrate-co-valerate) (PHBV) and natural bamboo fiber. Fabrication of the biocomposites was carried out by injection molding following extrusion compounding of PHBV and bamboo fiber with 30 or 40 wt.% fiber. The mechanical, thermo-mechanical and morphological properties of the biocomposites were evaluated. Little variation in the thermo-mechanical and impact properties was observed when the fiber content was varied. The tensile modulus of biocomposites at 40 wt.% fiber improved by 175% as compared to that of neat PHBV. The theoretical tensile modulus of the biocomposites was calculated using Christensen’s equations and compared with the experimental results. It was found to be in near approximation to the experimental data. The storage modulus was affected slightly by the variation of fiber content from 30 to 40 wt.% in biocomposites. The heat deflection temperature of PHBV increased by 9 °C at 40 wt.% of fiber reinforcement. Morphological aspects and thermal stability were studied using scanning electron microscopy and thermo-gravimetric analysis, respectively. In addition, a comparative analysis of bamboo fiber–PHBV with wood fiber–PHBV biocomposites was performed. Statistical analysis of both biocomposites was carried out by performing a two-way ANOVA on their tensile and flexural moduli in order to evaluate the effect of fiber type and content in the PHBV matrix.     

Development of an optical stylus displacement sensor for surface profiling instruments

The main cause of irrational results from measurements made with optical stylus instruments is speckle noise in the reflected light. To reduce or eliminate speckle noise, we developed a new optical stylus profiling system consisting of a displacement measuring part using a knife-edge and a speckle noise measurement part. Using this new system, we measured profiles of machined materials. The results show that the new system can eliminate speckle noise and can achieve a level of measurement accuracy as high as that of a contact stylus instrument.     

大型硅晶片平面度精密纳米计量技术

描述了一种基于斜率传感器的大型硅晶片平面度扫描测量系统．采用二维斜率传感器对晶片表面扫描，以获得表面绕X和Y轴的倾斜度．斜率传感器装在X向滑板上，而晶片固定在可绕Z轴转动的主轴上．对斜率传感器Y向的输出积分，得到晶片表面各个同心圆上轮廓截面高度．对斜率传感器X向的输出积分，得到晶片表面沿X向的截面轮廓，从而获得各同心圆轮廓之间的关系．构建了一个包括基于自准直原理的小型斜率传感器、气浮主轴、气浮导轨的实验系统，提出一种斜率传感器现场标定方法，用此系统测量了直径300mm的硅晶片平面度。     

Radiologic diagnosis of pancreatic carcinoma

A library of thyroxine analogs and tracers was prepared, and their solution binding affinities for an anti-T4 Fab fragment were determined using a single high-density L-T4 biosensor surface in a BIAcore surface plasmon resonance instrument. The high-density L-T4 analog biosensor was calibrated by determination of the initial binding rate was of known concentrations of free anti-T4 Fab fragment in solution to the biosensor surface. A range of individual thyroxine analog and tracer concentrations was subsequently mixed with a fixed concentration of anti-T4 Fab fragment. The concentration of free anti-T4 Fab fragment in each solution at equilibrium was determined, and the equilibrium dissociation constant (KD) for each case was derived. The KD values determined in solution are compared to values determined by a direct kinetic analysis on the BIAcore instrument using individual biosensor surfaces.     

Seismic performance of group pile foundation with ground improvement during liquefaction

A pile foundation with ground improvement under the footing is a composite foundation with the objectives of enhancing the seismic performance and rationalizing the substructure by combining the pile foundation with ground improvement. Although the effectiveness of this method has been confirmed in previous studies for application to soft grounds, the applicability of this method to liquefiable grounds has yet to be fully investigated. In this study, therefore, centrifuge model tests and finite element analyses were conducted to clarify the effectiveness of this method and to ascertain the improvement in strength (stiffness) when the method is applied to a liquefiable ground. Firstly, in order to investigate the effect of an improved ground on the behavior of the pile foundation during liquefaction, dynamic centrifuge model tests were conducted for three cases with different strengths of the improved ground. Then, three-dimensional soil–water coupled finite element analyses of the centrifuge model experiments were performed to validate the applicability of the analytical method. After that, parametric studies, in which the strength of the improved ground and the input ground motion were changed, were conducted using the same analytical model. The results confirmed that the horizontal displacement of the pile heads was reduced by the improved ground even in the liquefiable ground, and that the effect of this reduction was more remarkable in cases of high stiffness of the improved ground. Furthermore, it was possible to reduce the bending moments at the pile heads by applying the ground improvement. However, since the bending moment at the boundary between the improved ground and the natural ground became the local maximum, there was an optimum stiffness of the ground improvement at which the maximum bending moment of the piles was reduced. This is because improving the ground around the pile heads has the same effect as extending the footing. It was thus concluded that the behavior of the pile foundation is similar to that of a composite foundation comprised of a caisson and group piles.     

Preparation of M metal/alumina-pillared mica composites (M = Cu, Ni) by in situ reduction of interlayer M ions of alumina-pillared fluorine micas

Alumina-pillared fluorine micas form micropores in the interlayer region and exhibit cation exchangeability. Reduction of 3d transition metal cations (Cu²⁺ and Ni²⁺) in the interlayer regions of the cation exchanged alumina-pillared micas was attempted using ethylene glycol or diethylene glycol. The Cu²⁺-exchanged pillared mica led to the formation of a pillared mica composite containing interlayer zero-valence Cu⁰ metal clusters along with Cu⁰ metal fine particles on external surfaces of pillared mica flakes when refluxed in either ethylene glycol or diethylene glycol. Ni²⁺ cations in the interlayer region were also found to be reducible by refluxing in diethylene glycol. The zero-valence metal contained in the refluxed products occurs in three forms: M⁰ clusters in the interlayer region, elongated fine particles sandwiched between silicate layers, and submicron spherical particles on external surfaces of mica crystals. The zero-valence metal/alumina-pillared mica composites thus obtained largely retained the micropore properties of the alumina-pillared micas.