Study on sustainable redevelopment of a densely built-up area in Tokyo by introducing a distributed local energy supply system

“Distributed local energy systems” had been expected to rationalize the supply of energy to built-up areas, but until now very little research has been performed to estimate the effect of their application to actual cities. In this research, therefore, a future vision for the year 2030 in the Sancha Area (SANCHA VISION 2030), a typical densely built-up area in Tokyo, has been elaborated including a simulation to estimate benefits from the application of distributed energy systems in terms of reduced energy consumption and CO₂ emissions as well as mitigation of the heat-island phenomenon. As a result, it was demonstrated that a “distributed local energy system”, which provides a district with both electrical power and heat through an integrated distribution system, may contribute to a considerable improvement in energy efficiency for those areas. In addition, it may also provide other benefits, including enhancement of living amenity and urban security in times of emergency.     

A Microcomputer System for Spatiotemporal Visual Receptive Field Analysis

A microcomputer system was developed to measure visual spatiotemporal receptive fields. The system performs three functions: 1) generation of a binary spatiotemporal white-noise stimulus, 2) acquisition of spike discharges from retinal ganglion cells, and 3) extraction of the linear part of the spatiotemporal receptive flelds by cross correlating the input against the output. We have applied this system to the measurement of the spatiotemporal receptive fields of cat and catfish retinal ganglion cells.     

Reduction of return current noise by energy‐compensating active control

A newly proposed energy‐compensating active control is implemented to reduce the return current noise which is caused by inverter‐driven electric car systems. The energy‐compensating active control detects the energy charged at the filter capacitor, and reduces the energy and current of the noise frequency component by simple feedback loop incorporated with the conventional motor torque controller. No additional sensors or circuit arrangements are necessary; therefore, the return current can be attenuated effectively without any further cost. The return current with an inverter system is measured using a current probe and an FFT analyzer, and it is shown that the 25‐Hz noise current is reduced by up to 10 dB with the control. The results reveal that the low‐frequency return current noise can be attenuated with the simple control scheme, which would expectedly reduce the size of filter reactors and capacitors to meet the current limit level of the signaling system's track relays. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(4): 84–91, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20615     

Temperature control for the expansion of artificial DNA motif

The DNA, which forms a double helical conformation by the highly selective base-pairing rule with the width of 2 nm, is one of the polymers utilized as a template for nanoparticle assembly. Then, holiday junction structure, where two different DNA double strands intersect and replace each complement strand, is an important artificial motif for forming two-dimensional mesh-like DNA morphology. In this study, the two-dimensional sheet with the mesh-like conformation is formed and the growth of the DNA morphology is controlled by changing the temperature in the formation process. The influence of the cooling procedure on the formation process of the two-dimensional DNA sheet is observed by atomic force microscope, and the formation of double strands in the process is traced by absorption spectra. The spectroscopic results demonstrate that the two-dimensional DNA sheet is strongly dependent on the correlation between the applied cooling process and the melting temperature of double helical conformation, and that the growth of the two-dimensional DNA sheet can be manipulated by the cooling procedure. Further, we will show the size control of the DNA sheet by mixing the designed DNA which inhibits the growth of the DNA sheet.     

Influence of SO3 on the Phase Relationship in the System CaO–SiO2–Al2O3–Fe2O3

The influence of the additive SO₃ on the phase relationships in the quaternary system CaO-SiO₂-Al₂O₃-Fe₂O₃ was investigated by observing the change of volume ratio of 3CaOSiO₂ (C₃S) to 2CaOSiO₂ (C₂S) + CaO (C) in the sintered material with the increase of SO₃ content. The primary phase volume of C₃S in the quaternary phase diagram shrank with the increase of SO₃ and disappeared when the SO₃ content exceeded 2.6 wt% in the sintered material. Changes in the peritectic reaction relationship between CaO (C), 2CaOSiO₂ (C₂S), 3CaOSiO₂ (C₃S), 3CaOAl₂O₃ (C₃A), 4CaOAl₂O₃Fe₂O₃ (C₄AF), and liquid were also observed and discussed.     

Chiral recognition ability of oligopeptide derivatives consisting of glutamyl residues

The effect of the constituting amino acid residue [Glu(OBzl)] number on the chiral recognition ability was investigated. Chiral recognition sites were prepared from oligopeptide derivatives (constituting amino acid residue number = three–five) by adopting alternative molecular imprinting. It was made clear that with a constituting amino acid residue number of four, the tetrapeptide derivative of Glu(OBzl) is the best candidate material to generate a chiral recognition site among eight types of oligopeptide derivatives in the study. The affinity constant between Ac‐L ‐Trp and a chiral recognition site ranged from 3.4 × 10³ to 1.08 × 10⁴ mol^?1 dm³, depending on the number of Glu(OBzl) residues in an oligopeptide derivative. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1302–1309, 2005     

Secondary neutral and ionized particle measurements under MeV-energy ion bombardment

We have measured both secondary neutral and ionized particles from an InSb target under 3.0 MeV Si ion bombardment. Measurements of both ions and neutrals have not been carried out so far in the MeV-energy range. The mass spectra and axial emission energy distributions of secondary particles were investigated. Secondary ions were measured with a linear- and a reflective-type time-of-flight technique, whereas secondary neutral particles were photo-ionized by a UV pulsed laser (ArF: 193 nm) and measured with a reflective-type time-of-flight technique. Different results were obtained for neutral particles in comparison with ionized particles. The mean energy of neutral Sb atoms was much lower than that of neutral In atoms, whereas the mean energies of secondary In and Sb ions were nearly equal.     

Improved Filtration Performance of Continuous Alumina-fiber-reinforced Mullite Composites for Hot-Gas Cleaning

The effect of filtration layer morphology on filtration performance at 673 K was investigated for continuous alumina-fiber-reinforced mullite composite filters that capture fly ash on their outer surfaces. Two types of filtration layers were prepared on the outer surfaces: a mono-layer consisting of mullite agglomerated particulates and a bi-layer, with mullite whiskers formed by a vapor-phase reaction and strongly adhered to the particulates exposed on the outer surfaces. For filters with mono-filtration layers, the filtration efficiency was improved slightly by increasing the filtration layer thickness. However, the maximum differential pressure increased during the filtration tests. Adhesion of whiskers to the outer surface decreased the maximum differential pressure to about one-third less than that with the mono-filtration layer. This low differential pressure remained constant throughout the duration of the test, with corresponding increases in filtration efficiency.     

Modified thermoelectric figure of merit estimated from enhanced mobility of [100] oriented beta-FeSi<Subscript>2</Subscript> thin film

The modification of thermoelectric figure of merit was estimated from enhanced mobility of [100] oriented beta-FeSi₂ film. beta-FeSi₂ on Si(001) substrate was prepared by molecular beam epitaxy method using an Fe source. The crystallographic orientation of beta-FeSi₂ film on Si(001) substrate was characterized by using X-ray diffraction. Using scanning electron microscopy, surface morphology and film thickness of samples were observed and estimated, respectively. The mobility of beta-FeS₂ film on Si(001) substrate were also characterized by Hall measurement at room temperature. A part of the enhancement of figure of merit was evaluated as the functions of mobility and crystallographic orientation of samples.