Removal of estrogens from water using activated carbon and ozone

Estrogens (estron: E1; estradiol: E2; estriol: E3) are major water pollutants. For the removal of estrogens, activated carbon (AC) and ozone treatments were employed, and the chemical oxygen demand (COD) and pH of a single solution and multiple solution systems were investigated. The removal of estrogens increased with the amount of AC. The percentage of removed estrogens by AC in the single solution system was greater than that in the ternary solution system. The estrogens were completely removed using ozone, which also reduced COD and pH. The removal of estrogens increased the water quality and decreased the amount of organic carbon.     

LCST phase separation and thermoreversible gelation in aqueous solutions of stereo-controlled poly(N-isopropylacrylamide)s

Stereoregular poly(N-isopropylacrylamide)s with controlled content of isotactic dyads have recently been synthesized, and interesting interference phenomena between LCST phase separation and high-temperature reversible gelation have been observed in their aqueous solutions. We develop a model solution in which dehydrated stereo-regular isotactic segments on polymers are driven into intermolecular cross-links leading to gelation. We theoretically calculate the phase diagrams for the varied content isotactic dyads and compare with the experimental data.     

Hydrothermal Wave Instability in a High-Aspect-Ratio Liquid Bridge of Pr > 200

The long-duration fluid physics experiments on a thermocapillary-driven flow have been carried out on the Japanese Experiment Module ‘Kibo’ aboard the International Space Station (ISS) since 2008. In these experiments, various aspects of thermocapillary convection in a half-zone (HZ) liquid bridge of high Prandtl number fluid have been examined under the advantages of the long-duration high-quality microgravity environment. In 2010, the authors succeeded to realize nonlinear convective fields in the HZ liquid bridge of rather high aspect ratio. Special attention was paid on to the complex convective fields, especially on the behaviors of the hydrothermal wave (HTW) over the free surface visualized by an infrared camera. In order to evaluate the characteristics of the nonlinear convective behaviors and their transition processes, the authors indicate the images taken by the infrared camera describing the time evolution of HTW, the spatio-temporal diagram, the Fourier analysis, and the pseudo-phase space, reconstructed from the time series of the scalar information of the liquid bridge, that is, surface temperature variation. In this paper, the authors introduce the signature of complex HTW behaviors observed at the long-duration on-orbit experiments, and make comparisons with some previous terrestrial and microgravity experiments.     

AI: A strategic technology in Japan?

The industrial society in Japan is now entering into a new era of an advanced information society or a network society. AI as a knowledge information processing technology is becoming an integral part of the society. This emerging era is being supported by the information industry.The Fifth Generation Computer System (FGCS) Project of Japan (ICOT, 1987) was initiated in 1982 as a part of major programme supported by Japan's Ministry of International Trade and Industry (MITI). Its objective is to develop parallel computer systems for knowledge information processing. The system is based on AI and logic programming. The Human Frontier Science Programme (HFSP, 1987), proposed by former Prime Minister Nakasone at the economic Summit held in Venice in 1987, aims at promoting basic research on human perception, cognition, and learning.This paper deals with the background of FGCS and HFSP, and the impact of AI technology on FGCS and HFSP within Japan.     

Performance of a photomultiplier tube with transmissive dynodes in a high magnetic field

The performance of a photomultiplier tube with transmissive dynodes was examined. We found that the amplification gain was higher than 10⁴ even in a magnetic field of 7.8 kG. The energy resolution for 662 keV gamma rays from ¹³⁷Cs was 12% fwhm measured using a NaI crystal at 7.8 kG. The time resolution was as good as about 200 ps at 7.8 kG for the light generated by 2 GeV pions when they passed through a 1 cm thick scintillator mounted on the tube.     

Experimental study on the effect of fission product gas release into blockage wake region using a simulated LMFBR fuel subassembly

The objective of this study is to evaluate temperature rise due to gas release in the wake region of LMFBR fuel subassemblies. The experiments were conducted in two sets of grid-spacer-type 37-pin bundles simulating LMFBR fuel subassemblies. In Test section 37GC, the central 24 subchannels were blocked by a stainless steel plate and in Test section 37GE one-half edge part (39 subchannels) of the total flow area was blocked by the same material. The experimental results were compared with data obtained in similar tests using a spacer wire-type pin bundle, designated 37WC. The temperature rises in 37GE and 37WC were nearly identical in value and effect of gas release rate. The marked agreement seems to imply that there is a limit in the content of released gas in the wake region. On the other hand, the temperature rise behind the central blockage in the grid-type bundle, where gas might easily flow out to the core flow region, was far less than in the other geometries.     

Influence of spatiotemporal coupling induced by an ultrashort laser pulse shaper on a focused beam profile

4f pulse shapers have been widely used to temporally manipulate femtosecond optical pulses by spectral filtering. When the temporal waveform is manipulated with a spatial light modulator consisting of segmented pixels, the spatial profile of the output beam also varies because of diffraction at the pixel array, which is known as a spatiotemporal coupling effect. This effect produces a complicated spatio-temporal profile near the focus of the ultrashort pulses, which may affect the interpretation of experimental results obtained with shaped ultrashort pulses. We investigate the spatial intensity distribution at the focus of temporally shaped pulses through ablation experiments. The three-dimensional space-time beam profile is also numerically calculated.     

Generating 1-DOF limit cycle walking at target walking speed by feed-forward and feedback limit cycle control

We propose the feed-forward and feedback (FaF) control systems for generating the limit cycle walking at a target walking speed by the combined rimless wheel (CRW) model. The proposed FaF control systems can calculate a control input constantly based on the mathematical analysis of the current and target walking states. As a result, first, the limit cycle walking at the target walking speed is generated by numerical simulations when the walker is driven by the constant FaF control system. Second, for controlling the convergence speed, we extend the FaF control to the two-period stepwise control systems. The limit cycle walking at the target walking speed is still generated, and the convergence speed is controlled by the settling time parameter. Finally, the real-time walking state updating is considered in the FaF control systems to handle the disturbances. In this case, we find that for generating a target walking speed, a precise mathematical model is not necessary for generating the target state, but can make the control input stable and efficient.     

Robust pseudo virtual passive dynamic walking with control of swing-leg retraction

This paper proposes a simplified method of underactuated virtual passive dynamic walking without having any singularities in the control input, which is termed as the pseudo virtual passive dynamic walking (PVPDW), and analyzes the gait properties considering quasiconstraint on the impact posture. First, we introduce a planar underactuated biped model that added an upper body by means of a bisecting hip mechanism and formulate the method of PVPDW based on the concept of pseudo center of mass. Second, we introduce a control law for inhibiting swing-leg retraction and analyze the effect on the gait stability. The simulation results show that falling down as a 1-DOF rigid body dramatically increases the stable domain even though the hip angle at impact is not precisely kept constant. Finally, we discuss the mechanism from the energy-loss coefficient point of view.