Liquid lens using acoustic radiation force

A liquid lens is proposed that uses acoustic radiation force with no mechanical moving parts. It consists of a cylindrical acrylic cell filled with two immiscible liquids (degassed water and silicone oil) and a concave ultrasound transducer. The focal point of the transducer is located on the oil-water interface, which functions as a lens. The acoustic radiation force is generated when there is a difference in the acoustic energy densities of different media. An acoustic standing wave was generated in the axial direction of the lens and the variation of the shape of the oil-water interface was observed by optical coherence tomography (OCT). The lens profile can be rapidly changed by varying the acoustic radiation force from the transducer. The kinematic viscosity of silicone oil was optimized to minimize the response times of the lens. Response times of 40 and 80 ms when switching ultrasonic radiation on and off were obtained with a kinematic viscosity of 200 cSt. The path of a laser beam transmitted through the lens was calculated by ray-tracing simulations based on the experimental results obtained by OCT. The transmitted laser beam could be focused by applying an input voltage. The liquid lens could be operated as a variable-focus lens by varying the input voltage.     

Molecular structure of La3+-induced methanol dehydrogenase-like protein in Methylobacterium radiotolerans

La(3+) and not Ca(2+) increases methanol dehydrogenase (MDH) activity in Methylobacterium radiotolerans NBRC15690. La(3+)- and Ca(2+)-MDH-like proteins were found to be homodimeric (α(2)) and heterotetrameric (α(2)β(2)), respectively. N-terminal amino acid sequences of these proteins revealed that La(3+)- and Ca(2+)-MDH-like proteins were encoded by xoxF and mxaFI, respectively.     

折叠之舞

这所住宅位于日本古老的首都--京都中心传统住宅街区内,由建筑师Kentaro Takeguchi+Asako Yamamoto/ALPHAVILLE共同设计建造。由于地区性建筑规范和邻里关系的制约,住宅外部延续了日本传统木制别墅的特征,尽量低调谦和地融入外部传统街区环境之中。当夜暮降临,透过住宅临街的木质格栅散透出柔和的暖光,晕染着这个     

Novel Fabrication of High-Quality ZrO2 Ceramic Thin Films from Aqueous Solution

We report on the direct deposition of high-quality ZrO₂ thin films on various kinds of substrates by the liquid phase deposition method. After reaction for 24 h, thin films formed on various kinds of substrates, and the obtained thin film was comprised of densely packed nano-sized particles. The film annealed at 500°C showed a tetragonal phase at room temperature and this phenomenon has been discussed from the viewpoint of crystallite size effect. The result of optical transmittance measurement revealed that high transparency, more than 70% transmittance, has been achieved for the film after annealing at 900°C.     

Studies of oxidation behaviors of CdTe in ammoniacal basic electrolytes

The time variations in the electrode potential and mass of an electrodeposited CdTe layer when immersed in a deposition bath under an open-circuit condition were examined using an electrochemical QCM in order to observe the oxidation behavior due to dissolved oxygen. The morphology, composition, and crystallinity of the CdTe layer were also examined by SEM, EPMA, and XRD measurements. In the early stage of immersion, mostly only Cd atoms in the CdTe were found to dissolve from the zinc blende-type CdTe lattice, keeping the flat and smooth surface morphology intact. Then, the remaining Te formed a lattice of elemental Te and covered the CdTe layer. The electrolyte could penetrate the Te layer and access the CdTe layer's surface because the Te layer was porous due to the elution of Cd atoms. Therefore, the preferential dissolution of Cd species continued to occur, and finally, only the porous Te layer remained on the substrate. This dissolution of CdTe supports the validity of the potential-pH diagram of the Cd-Te-NH₃-H₂O system.     

Behavioral responses of malePeriplaneta americana L. to female sex pheromone components,periplanone-A and periplanone-B

Bioassays were performed on malePeriplaneta americana L. using synthetic (–)-periplanone-B (P-B) and Hauptmann's (–)-periplanone-A (P-A), and their mixtures at various ratios to estimate the roles of both periplanones for the sexual communication of the species. Both P-A and P-B elicited qualitatively the same responses, such as antennal movement, rapid locomotion, wing raising, and homosexual behavior of male cockroaches, but the threshold of the pheromone activities for P-B was two orders of magnitude lower than that of P-A. Neither synergistic nor inhibitory but only a simple integrated effect on the responses was observed when mixtures of P-A and P-B were applied.     

Deformation of Alumina Droplets on Micro-Patterned Substrates Under Plasma Spraying Conditions

The deformation of plasma-sprayed alumina droplets of 35-55 μm diameter d with an impact velocity of around 90 m/s has been investigated over various micro-patterned substrates with an arithmetic mean roughness of 0.5 μm. On a line-and-space pattern, droplets exhibited elliptical splats extending in the direction perpendicular to the line, when the normalized pattern spacing λ (= x/d) was 0.1-0.3, where x is the pattern spacing. The fingering of the splats was also caused by a concave pattern as well as by a convex pattern and the number of fingers significantly increased at λ = 0.2. In addition, holes suggesting air entrapment were observed off center in the bottom side of each splat by approximately 1.5 times the radius of the droplets, regardless of the pattern. These results suggest the importance of the surface design of substrate on the micrometer scale in plasma spraying.     

Correlation between corrosion rate and AE signal in an acidic environment for mild steel

The AE method is an effective technique for inspecting corrosion damage of mild steel, such as tank bottom floors. However, the correlation between AE signals and corrosion behaviour for mild steel has not yet been fully clarified. In the present study, the authors considered that the corrosion regions of bottom floors become a strong acid environment by Cl⁻, as reported in a previous study. Thus, the polarization resistance for the test pieces of mild steel was measured with an AC impedance method under a strong acid environment. It was clear that the polarization resistance indicated the corrosion rate for a test piece of mild steel in the experiments. While measuring the AE signals, the corrosion rate was monitored with a test piece. As a result, the AE signal showed good correlation with the corrosion rates of the test pieces. The corrosion behaviour of the test pieces was then discussed with the corrosion potential measured during the experiments. Furthermore, the cathode current was changed to control the generated hydrogen gas volume. The volume of the hydrogen gas generated from the cathode reaction was correlated to the AE signals.     

Development of a frequency-detuned interferometer as a prototype experiment for next-generation gravitational-wave detectors

We report on our prototype experiment that uses a 4-m detuned resonant sideband extraction interferometer with suspended mirrors, which has almost the same configuration as the next-generation, gravitational-wave detectors. We have developed a new control scheme and have succeeded in the operation of such an interferometer with suspended mirrors for the first time ever as far as we know. We believe that this is the first such instrument that can see the radiation pressure signal enhancement, which can improve the sensitivity of next-generation gravitational-wave detectors.