Voltage and reactive power control by particle swarm optimization considering control process

This paper presents a new approach to optimal voltage and reactive power control based on a particle swarm optimization (PSO). According to the proposed method, one controller is selected by PSO and the number of control actions to the convergence of the objective function is taken into account. Thus, this method can be used to design a control process. So far, no methods using PSO algorithms for a control process have been proposed. The effectiveness of the proposed method is demonstrated by application to 15‐bus and 118‐bus systems. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(1): 9–18, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20055     

Anomalous dissolution property enhancement of naringenin from spray-dried particles with α-glucosylhesperidin

Spray-dried particles were prepared with α-glucosyl hesperidin (Hsp-G), a hesperidin derivative with enhanced water solubility, to improve the solubility profile of naringenin (NRG). Naringenin was used as a model hydrophobic polyphenol. The spray-dried sample of NRG in the presence of Hsp-G formed 3–4 μm spherical particles. Those particles showed a halo pattern in powder X-ray diffractometry, indicating the amorphous state of NRG in the solid dispersion with Hsp-G. Interestingly, the obtained powders dissolved immediately into the aqueous media and demonstrated dramatically high apparent solubility, over 60-fold greater than NRG crystals, when the loading ratio of NRG/Hsp-G was 1/20. The apparent solubility of NRG increased in proportion to the amount of Hsp-G loaded (R² > 0.99). These results suggested that a specific molecular interaction, a micelle-like structure in which NRG was incorporated with Hsp-G molecules, was formed in spray-dried particles, resulting in the anomalous enhancement in the solubility of NRG.     

Nonlinear analysis and damage monitoring of a one-sided patch repair with delamination

A simple analytical model using beam theory is developed to study a one-sided patch structure with delamination, considering the effect of large deflection and thermal stress. The method is based on the concept of equivalent delamination, which is analytically defined and employed to describe delay in load transfer between patch and parent plate with eccentrically aligned neutral axes. The analytical model has closed form solutions and good agreement with nonlinear finite element analysis (FEA) as well as experimental results is shown. The relation between the delamination propagation and the strains at monitoring locations is derived and feasibility of delamination monitoring based on surface strains is analytically demonstrated.     

Ultrasonic detection of moving interfaces in gas–liquid two-phase flow

Ultrasound reflects strongly off the gas–liquid interface when there is a large change in acoustic impedance. We exploit this phenomenon to detect the instantaneous position of the interface from the time of flight of pulsed ultrasound. Because the characteristics of the reflected wave depend on the shape and size of the interface relative to the ultrasound wavelength, the single-sensing principle is insufficient to capture the interface for generalized gas–liquid two-phase flows. In the present study, we design and examine three types of ultrasound interface detection techniques: the echo intensity technique, the local Doppler technique, and the velocity-variance technique, and investigate and compare the merits and limitations of each. The results indicate that the echo intensity technique is appropriate for turbulent interfaces that cause ultrasound scattering over wide angles. In contrast, the local Doppler technique is required to capture information from waves reflected from smooth interfaces and bubbles. Finally, we find that the velocity-variance technique works for quasi-steady and periodical two-phase flow, and we apply this technique to horizontal slug flow in a tube.     

Reaction-diffusion cellular automation using integratedmicroelectrodes

An experimental model of artificial reaction-diffusion systems, which provides a foundation for constructing future massively parallel molecular computers, is proposed. The key idea is to control redox-active molecules in solution by an array of integrated microelectrodes and to realise artificially programmable reaction-diffusion dynamics in a very small amount of solution     

Dimensional measurement of high aspect ratio micro structures with a resonating micro cantilever probe

 In non-destructive dimensional measurement of high aspect ratio micro structures (HARMS), optical methods cannot offer full three dimensional information due to the lack of observation light. Again, conventional mechanical measurement, such as a surface profiler or a coordinate measurement machine, cannot be applied because their stylus is too large. Furthermore, the AFM, though popular among the semiconductor industry, is also limited in terms of dimensional measurement, because its system is usually designed for planar samples. Thus, we have developed a new sensor-integrated micro resonating cantilever probe and a new dimensional measurement machine, which allows the probe's vertical access to microstructures in a sample. The new probe is made of tungsten carbide super hard alloy and possesses design flexibility according to its intended application. Validity of the system is confirmed through the measurement experiment of EDM drilled and chemically etched micro holes.     

Inclusion removal by bubble flotation in a continuous casting mold

Fundamentally based computational models are developed and applied to quantify the removal of inclusions by bubbles during the continuous casting of steel. First, the attachment probability of inclusions on a bubble surface is investigated based on fundamental fluid flow simulations, incorporating the turbulent inclusion trajectory and sliding time of each individual inclusion along the bubble surface as a function of particle and bubble size. Then, the turbulent fluid flow in a typical continuous casting mold, trajectories of bubbles, and their path length in the mold are calculated. The change in inclusion distribution due to removal by bubble transport in the mold is calculated based on the computed attachment probability of inclusions on each bubble and the computed path length of the bubbles. In addition to quantifying inclusion removal for many different cases, the results are important to evaluate the significance of different inclusion-removal mechanisms. The modeling approach presented here is a powerful tool for investigating multiscale phenomena in steelmaking and casting operations to learn how to optimize conditions to lower defects.     

Electrochemical study of modified cerium-silane bi-layer on Al alloy 2024-T3

In this paper, the performance of bis-1, 2-(triethoxysilyl) ethane (BTSE) as a pre-treatment to protect the AA 2024-T3 against corrosion has been investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curves, and the scanning vibrating electrode technique (SVET). The microstructural and morphological characterizations were carried out via scanning electron microscopy and atomic force microscopy and the chemical composition evaluated using contact angle measurements and X-ray photoelectron spectroscopy (XPS). The electrochemical results showed that the additives improved the anticorrosion properties of the coating. The chemical characterization indicated that additives contribute to an increased degree of surface coverage, as well as to a more complete reticulation. The SVET results evidenced the self-healing abilities of Ce ions.     

A case of glycogen storage disease type Ia with multiple hepatic adenomas and G727T mutation in the glucose-6-phosphatase gene, and a comparison with other mutations previously reported

We report a case of 23-yr-old man with glycogen storage disease (GSD) type Ia complicated by multiple hepatic adenomas. Analysis of the G-6-Pase gene using peripheral blood sample showed this patient to be homozygous for a G-to-T transversion at nucleotide 727 in exon 5. This mutation is prevalent among Japanese patients, suggesting that specific genotypes may correlate with different clinical courses or outcomes.     

Analysis and characterization of device variations in an LSI chip using an integrated device matrix array

For future large-scale integration design technology, the device matrix array (DMA), which precisely evaluates within-die variation in device parameters, has been developed. The DMA consists of a 14-by-14 array of common units. The unit size is 240 by 240 /spl mu/m, and each unit contains 148 measurement elements (52 transistors, 30 capacitors, 51 resistors, and 15 ring oscillators). The element selection and precise measurement are achieved with low parasitic resistance measurement buses and leakage-controlled switching circuits, which allow the measurement accuracy for a transistor, resistor, or capacitor of 90 pA, 11 m/spl Omega/, and 23 aF, respectively, in the 3/spl sigma/ range. The ability to obtain 29 008 samples from a chip enables statistical analysis of the variation in 148 elements of each chip with 240-/spl mu/m spatial resolution. This high resolution and large sample number allows us to precisely decompose the data into systematic and random variation parts with newly developed fourth-order polynomial fitting. Our methodology has been verified using a test chip fabricated by a 130-nm CMOS process with a 100-nm physical gate length and five Cu interconnect layers. In MOSFETs, the random part was dominant and indicated a certain /spl sigma/ value in every chip. In the case of the interconnect layers, the random and systematic parts of the resistance and the capacitance indicated variance fluctuations. By chip, by item, by size, by structure, random or systematic, the /spl sigma/ values of each variation show inconsistency which we believe is attributable to the Cu process. The correlation coefficients of systematic part between device element and ring oscillator frequency shown very high value (0.87-0.98), and those of a random part were low enough (-0.10-0.22) to prove the accuracy of decomposition.