Kusatsu, Japan

Ritsumeikan University

www.ritsumei.ac.jp
Kusatsu, Japan

Ritsumeikan University is a private university in Kyoto, Japan, tracing its roots to 1869. With the Kinugasa Campus in Kyoto, and Kyoto Prefecture. the university also has a satellite called Biwako-Kusatsu Campus .Today, the university is known as one of the four leading private universities in western Japan. KAN-KAN-DO-RITS 関関同立 is the abbreviation that many people refer to when talking about the four leading private universities in the region . The school is one of the top universities in Japan, and it is especially well known for its International Relations programme which has been ranked as first place in Japan. Moreover, in today’s newspaper, it is listed as the ‘top private university in Japan for policy science’. It has exchange programmes with many schools throughout the world, including The University of British Columbia, The University of Melbourne, The University of Sydney, University of Hong Kong and King's College London. The school also has a dual bachelor's degree program and dual masters' degree programme offered in collaboration with American University, and a dual bachelor's degree programme offered in collaboration with The University of British Columbia. It has a relatively strong network of alumni in Kansai region and has produced a number of CEOs in Japanese companies as well as politicians.Ritsumeikan University Panthers is a very strong collegiate football team in Japan and won three national champions, seven collegiate champions, and nine conference champions. Wikipedia.

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News Article | May 2, 2017
Site: phys.org

A photograph of a resolution test chart displayed on the phosphor screen. Credit: Shunsuke Itaya, Masamichi Ohta, Yuuki Hirai, and Takamasa Kohmoto By replacing the phosphor screen in a laser phosphor display (LPD) with a luminescent solar concentrator (LSC), one can harvest energy from ambient light as well as display high-resolution images. "Energy-harvesting laser phosphor display and its design considerations", published recently by SPIE, the international society for optics and photonics, in the Journal of Photonics for Energy, describes the development, processes, and applications of an LPD. In a proof-of-concept experiment, lead author Ichiro Fujieda and his colleagues at Ritsumeikan University fabricated a 95 × 95 × 10 mm screen by sandwiching a thin layer of coumarin 6 with two transparent plates. These plates guided the photoluminescent (PL) photons emitted in both directions toward their edge surfaces. After removing the light source in a DMD-based commercial grade projector and feeding a blue laser beam into its optics, the screen generated green images. Attaching a photodiode with a 10 × 10 mm sensitive area on the bottom edge of the screen to record the power of the PL photons indicated that a fully covered version would harvest up to 71% of the incoming optical power. However, a ghost image was noticeable when displaying a high-contrast still image. The researchers address two aspects in their design considerations. First, tiling small modules and extracting the PL photons in each module reduces the thickness of a large-area system and alleviates the effect of self-absorption. For seamless tiling, attaching an output coupler to the wave guiding plate and mounting solar cells provides an optimal solution. Second, the origin of the ghost image is the PL photons reflecting at the interface between the rear plate and the outside environment. By reducing the thickness of the rear plate on the LPD, they were able to eliminate this optical cross-talk between pixels. Journal of Photonics for Energy associate editor Loucas Tsakalakos called the study "a unique and novel application of a luminescent solar concentrator for display applications. The work shows practical operation of such a device, describes the basic operational principle and expected energy harvesting capability of such a system, and describes ways of improving the design in future work." Explore further: Researchers use laser-generated bubbles to create 3-D images in liquid More information: Ichiro Fujieda et al, Energy-harvesting laser phosphor display and its design considerations, Journal of Photonics for Energy (2017). DOI: 10.1117/1.JPE.7.028001

Imanaka T.,Ritsumeikan University
Proceedings of the Japan Academy Series B: Physical and Biological Sciences | Year: 2011

I reflect on some of our studies on the hyperthermophilic archaeon, Thermococcus kodakarensis KOD1 and its enzymes. The strain can grow at temperatures up to 100 °C, and also represents one of the simplest forms of life. As expected, all enzymes, DNA, RNA, cytoplasmic membrane, and cytoplasmic solute displayed remarkable thermostability, and we have determined some of the basic principles that govern this feature. To our delight, many of the enzymes exhibited unique biochemical properties and novel structures not found in mesophilic proteins. Here, I will focus on some enzymes whose three-dimensional structures are characteristic of thermostable enzymes. I will also add some examples on the stabilization of DNA, RNA, cytoplasmic membrane, and cytoplasmic solute. © 2011 The Japan Academy.

Yoshikawa T.,Ritsumeikan University
Annual Reviews in Control | Year: 2010

Robot hands have been one of the major research topics since the beginning of robotics because grasping and manipulation of a variety of objects by robot hands are fundamental functionalities of various robotic systems. This paper presents a survey on the current state of research on control of grasping and manipulation by multifingered robot hands. After a brief history of the hardware development of multifingered robot hands, representative theoretical research results are presented in the area of grasping and manipulation. Regarding grasping, basic analytical concepts including force/form closures and active/passive closures are explained and various grasp quality measures for grasping position optimization are introduced. Regarding manipulation, the hybrid position/force control method and impedance control method are presented. Some of our recent results on grasping and manipulation by a soft-fingered hand are also presented. Finally, some future research directions are discussed. © 2010 Elsevier Ltd. All rights reserved.

Physical Review Letters | Year: 2012

The molecular and cellular basis of left-right asymmetry in plant morphogenesis is a fundamental issue in biology. A rapidly elongating root or hypocotyl of twisting mutants of Arabidopsis thaliana exhibits a helical growth with a handedness opposite to that of the underlying cortical microtubule arrays in epidermal cells. However, how such a hierarchical helical order emerges is currently unknown. We propose a model for investigating macroscopic chiral asymmetry in Arabidopsis mutants. Our elastic model suggests that the helical pattern observed is a direct consequence of the simultaneous presence of anisotropic growth and tilting of cortical microtubule arrays. We predict that the root helical pitch angle is a function of the microtubule helical angle and elastic moduli of the tissues. The proposed model is versatile and is potentially important for other biological systems ranging from protein fibrous structures to tree trunks. © 2012 American Physical Society.

Fukuyama T.,Ritsumeikan University
International Journal of Modern Physics A | Year: 2012

This is a theoretical review of exploration of new physics beyond the Standard Model (SM) in the electric dipole moment (EDM) in elementary particles, atoms and molecule. EDM is a very important CP violating phenomenon and sensitive to new physics. Starting with the estimations of EDM of quarksleptons in SM, we explore new signals beyond SM. However, these works drive us to wider frontiers where we search fundamental physics using atoms and molecules and vice versa. Paramagnetic atoms and molecules have great enhancement factor on electron EDM. Diamagnetic atoms and molecules are very sensitive to nuclear P and T odd processes. Thus EDM becomes the keyword not only of New Physics but also of unprecedented fruitful collaborations among particle, atomic and molecular physics. This review intends to help such collaborations over a wide range of physicists. © 2012 World Scientific Publishing Company.

Sugawara Y.,Ritsumeikan University
Journal of High Energy Physics | Year: 2012

We study the thermodynamical torus partition function of superstring on the near-extremal black NS5-brane background. The exact partition function has been computed with the helps of our previous works: [arXiv:1012.5721 [hep-th]], [arXiv:1109.3365 [hep-th]], and naturally decomposed into two parts. The first part is contributed from strings freely propagating in the asymptotic region, which are identified as the superstring gas at the Hawking temperature on the linear-dilaton background. The second part includes the contribution localized around the 'tip of cigar', which characterizes the non-extremality. Remarkably, the latter part includes massless excitations with non-vanishing thermal winding, which signifies that the Hagedorn-like behavior effectively appears, even though the Hawking temperature is much lower than the Hagedorn temperature. We also explore the high-temperature backgrounds defined by the orbifolding along the Euclidean time direction. In those cases, the thermal winding modes localized around the tip are found to be tachyonic, reflecting the singularities of Euclidean backgrounds caused by orbifolding. © 2012 SISSA.

Fukuyama T.,Ritsumeikan University
International Journal of Modern Physics A | Year: 2013

We review SO(10) grand unified theories (GUTs) in four and five dimensions (4D and 5D). The renormalizable minimal SO(10) SUSY GUT is the central theme of this paper. It is very predictive and makes it possible to construct all mass matrices including those of the Dirac and heavy right-handed Majorana neutrinos. Its predictions covers all ranges of particle phenomena. The explicit construction of the Higgs superpotential and the explicit display of a symmetry breaking pattern from GUT to the SM show that the naive desert from the SM to GUT in the minimal supersymmetric standard model (MSSM) is a too simplified concept and we have many definitely determined intermediate energy scales in general. This situation destroys the naive gauge coupling unification in the MSSM scheme. Also the precise measurements of neutrino oscillation data have revealed several small but manifest mismatches with our predictions. Also there are arguments that it is impossible to construct a GUT theory in 4D with a finite number of multiplets that leads to the MSSM with a residual R symmetry. If we try to solve all these pathologies comprehensively, it is very attractive for us to go into extra dimensions. Extra dimension may be either warped or flat. The fifth dimension, for simplicity, is compactified on the S 1/(Z2) (warped) or on the S1/(Z 2×Z′2) (flat) orbifold with two inequivalent branes at the orbifold fixed points. In the former warped case, intermediate energy scales are translated with the positions of Higgs fields in the bulk and the fundamental scheme of the MSSM is recovered. On the other hand, in the latter flat scenario, all matter and Higgs multiplets reside on the Pati-Salam (PS) brane where the PS symmetry is manifest. There the original renormalizability in Yukawa coupling is broken but its essential structures of mass matrices in minimal SO(10) GUT in 4D is promoted to the PS invariant action in 4D. In the gaugino mediation mechanism, the SO(10) gauge multiplet is transmitted to the PS brane through the gaugino mediation with bulk gauge multiplet. Further breaking of the PS gauge group to the SM group is realized by VEVs of the Higgs multiplets $({\bf 4}, {\bf 1}, {\bf 2}) \oplus (\bar{\bf{4}}, {\bf 1}, {\bf 2})$. We show that this model not only cures all pathologies in SO(10) GUT in 4D but also provides the consistent inflation scenario and dark matter candidate and leptogenesis. The gauge coupling unification is successfully realized after incorporating the threshold corrections of the Kaluza-Klein modes. Finally we add some comments on the impacts of the discovery of a Higgs-like particle by the Large Hadronic Collider at CERN (LHC) on SUSY GUTs. © 2013 World Scientific Publishing Company.

Miyatake T.,Ryukoku University | Tamiaki H.,Ritsumeikan University
Coordination Chemistry Reviews | Year: 2010

Chlorophyll molecules are well organized for efficient energy or electron transfer in a light-harvesting antenna or a reaction center of photosynthetic organisms. In order to make effective photosynthetic mimics, self-aggregates of natural chlorophylls and their synthetic analogues have been prepared with the specific intermolecular interactions. Many studies have been carried out to prepare aqueous chlorophyll aggregates by use of surfactants or chemical modifications of the natural pigments, because chlorophylls basically are poorly soluble in water. This review article focuses on the preparation and function of aqueous chlorophyll aggregates used in making artificial photosynthetic systems. © 2009 Elsevier B.V.

Wang X.-F.,Gifu University | Tamiaki H.,Ritsumeikan University
Energy and Environmental Science | Year: 2010

In this Perspective, recent progress on dye-sensitized solar cells (DSSCs) based on cyclic tetrapyrrole type sensitizers including porphyrins, (bacterio)chlorins, and phthalocyanines has been reviewed. Cyclic tetrapyrrole type molecules have been studied extensively with respect to their photochemical and photophysical properties as well as to various applications. The photophysical properties of tetrapyrrole molecules can be readily controlled upon molecularly structural modification. Their low-lying singlet states are also suitable for studying excited state dynamics in the electron donor-acceptor systems. Here, we selected the most representative porphyrin, (bacterio)chlorin, and phthalocyanine sensitizers to discuss how those structural modifications on the cyclic tetrapyrrole rings affect the performance of DSSCs. The most important factors that strictly determine the power conversion efficiencies of DSSCs based on tetrapyrrole type sensitizers are also discussed in detail. © 2010 The Royal Society of Chemistry.

Maeda H.,Ritsumeikan University
Bulletin of the Chemical Society of Japan | Year: 2013

This article summarizes the supramolecular chemistry of pyrrole-based π-conjugated molecules, with specific focus on the work carried out by the author's group over the last nine years. The author provides a number of examples of supramolecular assemblies and functional materials comprising pyrrole-based molecules stabilized by noncovalent interactions such as metal coordination, hydrogen bonding, π-π stacking, and van der Waals forces. In particular, pyrrolebased π-conjugated molecules showed anion-binding behavior, and formed ion-based materials, wherein positively and negatively charged species were arranged in an ordered form by combination with appropriate cations. © 2013 The Chemical Society of Japan.