Analog Integrated Circuit for Motion Detection of Approaching Object Based on the Insect Visual System

A network for detection of an approaching object was proposed and fabricated based on the transient response of a descending contralateral movement detector (DCMD) existing in the brain of locusts. The proposed network was constructed with simple analog circuits. The experimental results of a test chip fabricated with a 1.2 $mUm complementary metal-oxide-semiconductor (CMOS) process and the results with a simulation program with integrated circuit emphasis (SPICE) showed that the proposed network is able to detect the approach by generating a peak current just before collision; the peak current allows detection of the approaching velocity and direction without collision. The proposed network could be applied to two-dimensional arrays for three-dimensional motion detection.     

Optical Characteristics of the Retroreflector in Space on the ADEOS Satellite in Orbit

Optical characteristics of the retroreflector in space (RIS) on the Advanced Earth Observing Satellite (ADEOS) in orbit were tested using a second harmonics Nd:YAG laser. The intensity of reflection from the RIS was analyzed with an intensified charge coupled device camera by comparing the image with those of stars. It was confirmed that the RIS in orbit is working properly as a retroreflector.     

The development of a three-dimensional T1 image calculation program in proportion to the DICOM data of any marketing clinical MRI systems

Contrast media such as gadolinium-diethlene-triamine pentaacetic acid (Gd-DTPA) is used for MRI. Recently there have been some reports about diagnosis using contrast media for the MRI T(1) image for the quantitative evaluation of articular cartilage degeneration. This may be a useful method to evaluate the lesion of the articular cartilage or to confirm therapeutic progress. Whether or not contrast is used, the use of the calculated T(1) image is effective for the quantitative evaluation of the degeneration of knee joint cartilage. However, our system copes with the format of every MRI image even if software of the calculated T(1) image isn't often prepared in the commercial MRI device. So, we developed general purpose image data processing software that can be processed on the preexisting three-dimensional image data processing system.     

Knots,links, braids and exactly solvable models in statistical mechanics

We present a general method to construct the sequence of new link polynomials and its two variable extension from exactly solvable models in statistical mechanics. First, we find representations of the braid group from the Boltzmann weights of the exactly solvable models. Second, we give the Markov traces associated with new braid group representations and using them construct new link polynomials. Third, we extend the theory into a two-variable version of the new link polynomials. Throughout the paper, we emphasize the essential roles played by the exactly solvable models and the underlying Yang-Baxter relation.     

From organic conductors to bio-conductors

Two major categories of organic solids are known to offer the prospect of electrical conduction. One of them consists of charge-transfer complexes such as BEDT-TTF salts. A large number of studies on charge-transfer complexes have been carried out and their conductivity ranges from semiconductor to superconductor. The other group comprises single component materials. Typical examples are polycyclic aromatic compounds and also phthalocyanines; their conductivities are not as good as those of the donor-acceptor kinds.¹⁾ As one of those single component organic semiconductors, a group of cytochromes, electron carrier in biological system, was offered. Cytochrome c₃ (molecular weight = 13,995, 107 amino acid residers), an electron carrier in the reactions of very negative potentials in cells of Desulfovibrio, has four homes in the molecule.     

Syntheses of 2‐alkylthio‐1,3‐thiazine derivatives from S‐alkyldithiocarbamates and α,β‐unsaturated ketones

Various 2‐alkylthio‐1,3‐thiazine derivatives were synthesized by the reactions of S‐alkylthiocarbamates with α,β‐unsaturated ketones in the presence of BF₃ · Et₂O. The thiazine was converted into two isomeric dehydrated products in the presence of a Lewis acid. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:377–379, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10055     

Temperature‐Responsive Graft Copolymers with Poly(propylene glycol) Side Chains

The phase behavior of graft copolymers in aqueous solution was investigated. The graft copolymers consist of poly(propylene glycol) (PPG) side chains and N,N‐dimethylacrylamide (dMA), N‐vinylimidazole (VIm), and N‐isopropylacrylamide (iPA), respectively, as backbones. Phase transition temperatures of the PPG copolymers increased with increasing the content of dMA and iPA as relatively more hydrophilic comonomers and with an increase in the degree of ionization of the incorporated VIm units.

Chemical structure of the graft copolymers