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.     

Characteristics of a crossed-wire scatterer without a junction point of an incident wave of circular polarization

A crossed-wire scatterer has the wires displaced in the backscattering direction, and is able to scatter an incident wave of circular polarization in such a way that the backscattering wave has the same rotational sense as that of the incident wave. The radiation performance of the scatterer is improved by bending the horizontal and the vertical wires. Arrays consisting of crossed-wire scatterers are constructed and the backscattering cross sections (BSCS's) are calculated. It is revealed that the increase in the current amplitude due to the mutual effects among the array elements contributes to enhancement in the BSCS. It is also shown that a maximum value of the BSCS of an array of3 times 3bent crossed-wire scatterers is 1.8 times as large as that of a dihedral corner reflector which has the same aperture area. The BSCS's as a function of the angle of incidence are presented with experimental results at a frequency of 9.375 GHz.     

Modeling of extraction behavior of docosahexaenoic acid ethyl ester by utilizing slug flow prepared by microreactor

The liquid–liquid extraction dynamics of an ethyl ester of docosahexaenoic acid (DHA‐Et) with silver ion was investigated. The kinetic model was derived according to the following stepwise processes: Diffusion of DHA‐Et across the organic film, complex‐formation between DHA‐Et and silver ion at the interface, and diffusion of extracted complex across the aqueous film. The kinetic parameters for the complex‐formation reaction were determined from the investigation with the stirred transfer cell. With the proposed model and determined parameters, we predicted the uptakes of DHA‐Et for the extraction system utilizing a slug flow prepared by a microchip. The calculated uptakes showed good correlation to the experimental data. The theoretical investigation suggested that the fast equilibration realized for the slug flow extraction system was due to the large specific interfacial area of the slug caused by the presence of wall film and the thin liquid film caused by the internal circulation. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

Analyses of liquid film models applied to horizontal and near horizontal gas–liquid slug flows

An analysis of liquid film models for horizontal and near horizontal gas–liquid slug flows is developed. The models’ formulations employ the one dimensional separated phase momentum equations. The formulations differ among themselves, by neglecting some terms on the momentum balance and also on the closure relations. A comparative analysis discloses the differences amongst the formulations. The sensitivity of the liquid film models to the changes on the bubble velocity, liquid slug holdup and liquid viscosity is accessed through a series of parametric runs. Finally, the model is tested against experimental data taken for continuous horizontal slug flow. The tests were designed to check if the models are able to capture the stochastic film properties provided the properly closure relations.     

Study of prediagnostic selenium level in toenails and the risk of advanced prostate cancer

BACKGROUND: In a recent randomized intervention trial, the risk of prostate cancer for men receiving a daily supplement of 200 microg selenium was one third of that for men receiving placebo. By use of a nested case-control design within a prospective study, i.e., the Health Professionals Follow-Up Study, we investigated the association between risk of prostate cancer and prediagnostic level of selenium in toenails, a measure of long-term selenium intake. METHODS: In 1986, 51,529 male health professionals aged 40-75 years responded to a mailed questionnaire to form the prospective study. In 1987, 33,737 cohort members provided toenail clippings. In 1988, 1990, 1992, and 1994, follow-up questionnaires were mailed. From 1989 through 1994, 181 new cases of advanced prostate cancer were reported. Case and control subjects were matched by age, smoking status, and month of toenail return. Selenium levels were determined by neutron activation. All P values are two-sided. RESULTS: The selenium level in toenails varied substantially among men, with quintile medians ranging from 0.66 to 1.14 microg/g for control subjects. When matched case-control data were analyzed, higher selenium levels were associated with a reduced risk of advanced prostate cancer (odds ratio [OR] for comparison of highest to lowest quintile = 0.49; 95% confidence interval [CI] = 0.25-0.96; P for trend = .11). After additionally controlling for family history of prostate cancer, body mass index, calcium intake, lycopene intake, saturated fat intake, vasectomy, and geographical region, the OR was 0.35 (95% CI = 0.16-0.78; P for trend = .03). CONCLUSIONS: Our results support earlier findings that higher selenium intakes may reduce the risk of prostate cancer. Further prospective studies and randomized trials of this relationship should be conducted.     

Pulmonary arterial impedance analysis by the use of the oscillated assist flow

Pulmonary arterial impedance is an important and interesting characteristic that can be used to evaluate the physiological properties of the pulmonary vessel. However, power spectrum analysis of the pulmonary artery pressure and flow pattern have suggested that peak power in the relatively high frequency range (> 10 Hz) is significantly low; thus, we cannot analyze the vessel properties in the high frequency range. In this study, we used the newly developed vibrating flow pump (VFP), which can generate oscillated blood flow with a relatively high frequency (10-50 Hz) for right heart bypass, to evaluate the pulmonary arterial impedance pattern in the high frequency range. Acute animal experiments of the right heart bypass from the right atrium to the pulmonary artery using 6 healthy adult goats were performed. The flow pattern and pressure of the pulmonary artery, electrocardiograms (ECGs), and arterial and right atrial pressures were continuously monitored during the experiments. Spectral analysis of the hemodynamic parameters using the fast Fourier transform (FFT) method was performed to evaluate the spectral properties. The coherence function, transfer function, and phase patterns were calculated to analyze the impedance pattern in the relatively high frequency area. Previously, various investigators had tried to analyze the impedance patterns of the pulmonary artery; however, they could not analyze the impedance patterns over 10 Hz because the spectral patterns of the pulmonary flow do not have high power at high frequencies. These physiological analyses may be useful in designing the optimal pulmonary circulation.     

Scalable architecture for word HMM-based speech recognition and VLSI implementation in complete system

This paper describes a scalable architecture for real-time speech recognizers based on word hidden Markov models (HMMs) that provide high recognition accuracy for word recognition tasks. However, the size of their recognition vocabulary is small because its extremely high computational costs cause long processing times. To achieve high-speed operations, we developed a VLSI system that has a scalable architecture. The architecture effectively uses parallel computations on the word HMM structure. It can reduce processing time and/or extend the word vocabulary. To explore the practicality of our architecture, we designed and evaluated a complete system recognizer, including speech analysis and noise robustness parts, on a 0.18-/spl mu/m CMOS standard cell library and field-programmable gate array. In the CMOS standard-cell implementation, the total processing time is 56.9 /spl mu/s/word at an operating frequency of 80 MHz in a single system. The recognizer gives a real-time response using an 800-word vocabulary.     

Integrated optical-disk pickup that uses a focusing grating coupler with a high numerical aperture

An integrated optical-disk pickup that uses a focusing grating coupler with a numerical aperture of 0.45 (a focal length of 1.0 mm and an aperture of 1.0 mm × 0.8 mm) was developed, and the readout signal on an International Standards Organization (ISO) -formatted 90-mm optical disk was detected by the pickup. The signal-amplitude ratio of the minimum-limit data pattern to the maximum was 0.53 on the innermost track. It meets the requirement on the signal resolution for optical-disk storage devices.     

Switched-Capacitor Track-and-Hold Amplifiers With Low Sensitivity to Op-Amp Imperfections

This paper describes high-precision switched-capacitor (SC) track-and-hold amplifier (THA) stages. They use a novel continuous-time correlated double sampling (CDS) scheme to desensitize the operation to amplifier imperfections. Unlike earlier predictive-CDS amplifiers, the circuits do not need a sampled-and-held input signal for their operation. During the tracking period, an auxiliary continuous-time signal path is established, which predicts the output voltage during the holding period. This allows accurate operation even for low amplifier gains and large offsets over a wide input frequency range. Extensive simulations were performed to compare the performance of the proposed THAs with earlier circuits utilizing CDS. The results verify that their operation is far more robust than that of any previously described SC amplifiers