Muguruma H.,Shibaura Institute of Technology
Plasma Processes and Polymers | Year: 2010
Developments in plasma-polymerized films used for the design of chip-based biosensors, commonly referred to as biochips, are described. Plasma-polymerized films are suitable for the design of an interface between biological components and physical transducers, which are the two well-known main parts of biochips. The roles and advantages of plasma-polymerized films in biochip design are highlighted. Mainly, plasma-polymerized films can play an important role in the control and manipulation of biological components on different spatial regions (patterning), while retaining their activity. In addition, dry-process-based plasma-polymerization are compatible with biochip fabrication processes. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Tanaka K.,Shibaura Institute of Technology
Current Applied Physics | Year: 2010
A preliminary design of solar thermal generating system using alkali metal thermal to electric converter (AMTEC) is proposed and discussed in this paper. High conversion efficiency, compactness, lightweight, and maintenance free are its characteristics. A vapor-condense-type AMTEC cell incorporated in a solar receiver of about 10 kWe in size was designed. The thermal energy flow for the designed receiver has been calculated and examined. The analysis has been conducted under two operating conditions, maximum efficiency mode and maximum output power mode. On the maximum efficiency mode, the calculated conversion efficiency is 27% for the AMTEC system and 19% for the overall receiver system with the output power is 10.3 kWe at 1000 K. On the maximum output power mode, the conversion efficiency is 20% for the AMTEC system and 17% for the overall receiver system with the output power is 19.1 kW e at 1000 K. The preliminary calculated result has shown that the solar-AMTEC generating system has performance advantage in the solar power generating systems. © 2009 Elsevier B.V. All rights reserved.
Iizuka N.,Kyoto University |
Maeda K.,Shibaura Institute of Technology
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013
We study the dynamical stripe instabilities on the geometries with hyperscaling violation in the IR, which asymptotically approach AdS4 in the UV. The instabilities break the translational invariance spontaneously and are induced by the axion term ∼aFâ̂§F in the bulk action. We first study the perturbation equations in the probe limit, and find that there is a strong correlation between the stripe instabilities caused by the axion term and parameters of the theories which determine the IR hyperscaling violation. Contrary to the IR AdS2 case, the effect of the axion term for the stripe instabilities can be enhanced/suppressed at low temperature depending on the parameters. For a certain one-parameter family of the hyperscaling violation, we find the onset of the stripe instability analytically in the axion coupling tuned model. For a more generic parameter range of hyperscaling violation, we study the instability onset by searching for the zero mode numerically on the full geometries. We also argue that quite analogous results hold after taking into account the graviton fluctuation, i.e., beyond the probe limit. © 2013 American Physical Society.
Zhai G.,Shibaura Institute of Technology
Proceedings of the IEEE Conference on Decision and Control | Year: 2012
We consider quadratic stabilizability and H∞ disturbance attenuation of switched systems which are composed of a finite set of linear time-invariant subsystems. The situation is that none of the subsystems is quadratically stable with certain H∞ disturbance attenuation level but a convex combination of the subsystems achieves such performance. We then design a state-dependent switching signal (state feedback) and an output-dependent switching signal (output feedback) such that the entire switched system is quadratically stable with the same H∞ disturbance attenuation level. In the case of state feedback, when the number of subsystems is two, we show that the existence of desired convex combination of subsystems is not only sufficient but also necessary for quadratic stabilizability with the H∞ disturbance attenuation of the switched system. © 2012 IEEE.
Tomita Y.,Shibaura Institute of Technology
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2014
At low temperatures, the two-dimensional continuous-spin systems exhibit large correlation lengths. Some of them show the Berezinskii-Kosterlitz-Thouless-like transitions, and some others show pseudocritical behaviors for which correlation lengths are extremely large but finite. To distinguish pseudo and genuine critical behaviors, it is important to understand the nature of spin-spin correlations and topological defects at low temperatures in continuous-spin systems. In this paper, I develop a finite-size scaling analysis which is suitable for distinguishing the critical behavior and its applications to the two-dimensional XY, Heisenberg, and RP2 models. © 2014 American Physical Society.