A 1.5-V full-swing BiCMOS logic circuit

A BiCMOS logic circuit applicable to sub-2-V digital circuits has been developed. A transiently saturated full-swing BiCMOS (TS-FS-BiCMOS) logic circuit operates twice as fast as CMOS at 1.5-V supply. A newly developed transient-saturation technique, with which bipolar transistors saturate only during switching periods, is the key to sub-2-V operation because a high-speed full-swing operation is achieved to remove the voltage loss due to the base-emitter turn-on voltage. Both small load dependence and small fan-in dependence of gate delay time are attained with this technique. A two-input gate fabricated with 0.3-μm BiCMOS technology verifies the performance advantage of TS-FS-BiCMOS over other BiCMOS circuits and CMOS at sub 2-V supply     

Series resonant ZCS‐PFM DC‐DC power converter with high‐frequency high‐voltage transformer link for high‐power magnetron drive

This paper presents a single lossless inductive snubber‐assisted ZCS‐PFM series resonant DC‐DC power converter with a high‐frequency high‐voltage transformer link for industrial‐use high‐power magnetron drive. The current flowing through the active power switches rises gradually at a turned‐on transient state with the aid of a single lossless snubber inductor, and ZCS turn‐on commutation based on overlapping current can be achieved via the wide range pulse frequency modulation control scheme. The high‐frequency high‐voltage transformer primary side resonant current always becomes continuous operation mode, by electromagnetic loose coupling design of the high‐frequency high‐voltage transformer and the magnetizing inductance of the high‐frequency high‐voltage transformer. As a result, this high‐voltage power converter circuit for the magnetron can achieve a complete zero current soft switching under the condition of broad width gate voltage signals. Furthermore, this high‐voltage DC‐DC power converter circuit can regulate the output power from zero to full over audible frequency range via the two resonant frequency circuit design. Its operating performances are evaluated and discussed on the basis of the power loss analysis simulation and the experimental results from a practical point of view. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(3): 79–87, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20126     

Intercalation of n-alkylamines into α-tin(IV) bis(hydrogenphosphate)

The intercalation reaction of n-alkylamines from methyl- to hexadecylamine into -tin(IV) bis(hydrogenphosphate) has been investigated. The reaction was conducted by mixing the phosphate and solutions of the amines dissolved in water or benzene. The amine/ phosphate molar ratios in the reaction mixtures were 0.43, 0.85, 1.71 and 3.41. The nitrogen/phosphorus atomic ratio in the intercalation compound was not changed by the amine/phosphate molar ratio. The interlayer distances of the intercalates obtained in the reaction mixtures with molar ratios of 3.41 and 1.71 increased with an increase in the number of carbon atoms in the alkyl chain of the amine. The slope of the straight line obtained in plot of interlayer distance versus number of carbon atoms in the alkyl chain of the amine indicates that the amine molecules form a double layer in the interlayer space of the phosphate and are inclined at an approximate angle of 67.7° to the phosphate layer. The interlayer distances of the intercalates of butyl- to nonylamines obtained at the molar ratio of 0.85 are smaller than those of the corresponding compounds from the molar ratios of 3.41 and 1.71, while those of decyl- to hexadecylamine intercalates lie on the previously discussed line. This behaviour is interpreted by assuming kink formation in the short alkyl chains between the phosphate layers.     

Reduction of system matrices of planar beam in ANCF by component mode synthesis method

A method of reducing the system matrices of a planar flexible beam described by an absolute nodal coordinate formulation (ANCF) is presented. In this method, we focus that the bending stiffness matrix expressed by adopting a continuum mechanics approach to the ANCF beam element is constant when the axial strain is not very large. This feature allows to apply the Craig–Bampton method to the equation of motion that is composed of the independent coordinates when the constraint forces are eliminated. Four numerical examples that compare the proposed method and the conventional ANCF are demonstrated to verify the performance and accuracy of the proposed method. From these examples, it is verified that the proposed method can describe the large deformation effects such as dynamic stiffening due to the centrifugal force, as well as the conventional ANCF does. The use of this method also reduces the computing time, while maintaining an acceptable degree of accuracy for the expression characteristics of the conventional ANCF when the modal truncation number is adequately employed. This reduction in CPU time particularly pronounced in the case of a large element number and small modal truncation number; the reduction can be verified not only in the case of small deformation but also in the case of a fair bit large deformation.     

Magnetic Correlation in BETS2(Cl2TCNQ)

We carried out⁷⁷Se NMR measurements on BETS₂(Cl₂TCNQ) under pressure in order to investigate the magnetic properties of the insulating state which appears above 0.6 GPa. The relaxation rate 1/T₁ at 0.7 GPa shows small peak-like anomaly at 20 K, indicating a spin density wave transition as observed in BETS₂(Br₂TCNQ).     

Photoreduction of Shewanella oneidensis Extracellular Cytochromes by Organic Chromophores and Dye‐Sensitized TiO2

The transfer of photoenergized electrons from extracellular photosensitizers across a bacterial cell envelope to drive intracellular chemical transformations represents an attractive way to harness nature's catalytic machinery for solar‐assisted chemical synthesis. In Shewanella oneidensis MR‐1 (MR‐1), trans‐outer‐membrane electron transfer is performed by the extracellular cytochromes MtrC and OmcA acting together with the outer‐membrane‐spanning porin ? cytochrome complex (MtrAB). Here we demonstrate photoreduction of solutions of MtrC, OmcA, and the MtrCAB complex by soluble photosensitizers: namely, eosin Y, fluorescein, proflavine, flavin, and adenine dinucleotide, as well as by riboflavin and flavin mononucleotide, two compounds secreted by MR‐1. We show photoreduction of MtrC and OmcA adsorbed on Ru^II‐dye‐sensitized TiO₂ nanoparticles and that these protein‐coated particles perform photocatalytic reduction of solutions of MtrC, OmcA, and MtrCAB. These findings provide a framework for informed development of strategies for using the outer‐membrane‐associated cytochromes of MR‐1 for solar‐driven microbial synthesis in natural and engineered bacteria.     

Moisturizing effect of vesicles formed from monoglycerides on human skin

The moisturizing effect of vesicles formed from monoglycerides on human skin was studied by measurement of conductance on and transepidermal waterloss from the skin surface. Although sonication of the monoglycerides in water with Ca2+ gave multilamellar vesicles, the lamellar structure of the vesicles disappeared during their storage without any other additive. With the addition of poly(vinylpyrrolidone) after the sonication, the stability of the vesicles increased and their lamellar structure was maintained for 3 months at 40 degrees C. These vesicles led to a significantly higher water content of the stratum corneum of human skin compared with non-lamellar monoglyceride, and consequently they improved rough human skin.     

CFD modeling of snowdrift around a building: An overview of models and evaluation of a new approach

The first part of this paper provides an overview of Computational Fluid Dynamics (CFD) modeling of snowdrift around a building by reviewing previous research including the authors’ in order to clarify its applicability and limitations. It is clarified that a quantitative validation study in particular by predicting snow depth distribution near a building is not enough, even though many models have been proposed. The latter part presents the results of CFD prediction of snowdrift around a cubic building model using a new approach of a snowdrift model based on experimental and numerical studies by the authors. The numerical results are compared with data obtained from detailed field measurements and previous CFD in order to confirm the accuracy of the new model. This new approach shows good correspondence with results obtained from field measurements and wind tunnel experiments in terms of not only snowdrift patterns but also quantitative distribution of snow depth.