Ritsumeikan University Research Articles

High Capacity Sulfurized Alcohol Composite Positive Electrode Materials Applicable for Li-S Batteries

Introduction Elemental sulfur is one of the promising cathode active materials for high-energy rechargeable lithium batteries because of its high theoretical capacity (ca. 1670 mAh-g-1) and relatively low cost [1]. However, sulfur cathode has some disadvantages, such as low electrical conductivity and dissolution as polysulfides into electrolyte during electrochemical cycling, resulting in shuttling in Li-S batteries. Several attempts have been performed to solve these problems, and the major improvements have been made by forming composites with carbon matrix, whereby sulfur was physically confined in some fine structures [2]. Despite the improved electrical transfer and the suppressed shuttling of polysulfides, these S-C composites cells still showed gradual capacity degradation. This is originated from the low binding energy between sulfur and carbon matrix [3].Another type of S-C composites has been developed, based on the concept of embedding sulfur into a conductive polymer matrix, such as sulfurized poly(acrylonitrile) (S-PAN) [4-6]. In these organosulfur materials, sulfur is thought to be incorporated in cavity of molecular scale, which significantly prevents the dissolution as polysulfides, leading to the excellent cycle stability of the cells. Although many kinds of polymer framework have been investigated, there still remain challenges for exploring the organosulfur materials with higher sulfur contents, using inexpensive and non-toxic reagents [3]. In the present work, we have tried to prepare new type of organosulfur cathode materials using primary alcohol. The structure and the electrochemical properties of the obtained sulfurized alcohol composites (SAC) were examined. Experiments SAC was prepared by refluxing primary alcohol 1-C n H2n+1OH (n = 3 – 10) (1g) and elemental sulfur (5g) in a glass tube equipped in an electric furnace, which was heated at 400oC. After cooling, the resulting powder was ground and then heated again at 300oC under N2 flow in order to eliminate residual elemental sulfur to yield the SAC. We also prepared S-PAN after the method reported previously [7]. The obtained SAC was characterized by XRD, Raman spectroscopy, TEM observation, and elemental analysis, as well as S and C K-edge XAFS measurements (SR Center, Ritsumeikan University). Electrochemical lithium insertion / extraction reactions were carried out at 30oC using lithium coin-type cells with 1M LiPF6 / (EC + DMC) electrolyte at a current density of 30 mA-g-1 between 1.0 and 3.0 V initially with discharging. The electrochemical performances were also examined by assembling all-solid-state cells using the Li2S-P2S5 solid electrolyte and indium anode in a similar manner as described previously [8] at a current density of 30 mA-g-1 between 0.4 and 3.5 V. Results and Discussion The obtained SAC samples were black in color, and the XRD patterns showed no significant peaks, irrespective of the primary alcohol (n-value). High-resolution TEM observations showed no obvious crystalline domains, indicating an amorphous phase. The EDX mapping showed relatively homogeneous distribution of sulfur and carbon in the SAC samples. The elemental analyses indicated that the sulfur content was more than 60 wt%, which was higher than that reported previously for S-PAN (ca. 30 – 53 wt%) [4,5]. The Raman spectra showed some peaks at 480, 1250, 1440cm-1, suggesting the S-S, C-S, and C-C bonds, respectively. Analyses of the D- and G-bands indicated that the C-C bonds mainly consisted of sp3-type configuration, which makes a clear contrast to the S-PAN where the C-C bonds consisted of mainly sp2-configuration.The electrochemical tests for the SAC sample cells showed that the initial discharge capacity was ca. 800 - 1000 mAh-g-1, which was higher than that of S-PAN, due possibly to higher sulfur contents. Also, the all-solid-state cells with the SAC samples showed the discharge capacity of ca. 600 – 800 mAh-g-1. The charge/discharge mechanism was examined using S and C K-edge XAFS measurements, and the results will be presented in the conference. Acknowledgment This work was financially supported partly by “Next-generation storage battery material evaluation technology development” project of NEDO and METI, Japan.

Keynote Speakers

Discontinuous functions have featured in metric fixed point theory since the theory originated in the first quarter of the 20th century. Today these functions occupy a large portion of this expanding branch of mathematics. The present talk gives an account of the recent developments of this area of research along with some of its implications. The broad subject area of the talk is functional analysis.

Special issue on IAPR MVA2013 best papers

With a number of successful deployments of various applications enabled bymachine vision technologies in recent years, there is an increasing demand for machine vision applications to provide a key solution for emerging issues, with high impact on industry, society, and our everyday lives. In particular, machine vision applications are expected to play a fundamental role in solving important problems in safety, security, environmental, and industrial issues on a global scale. With the proliferation of camera networks consisting of low-cost/high-performance image sensors, and recent increases in computational power, the basic infrastructure is now readily available to support smart systems for various applications such as factory automation, surveillance, intelligent transport systems, and sensor networks for environmental monitoring. Our current challenge is to develop keymachine vision technologies and systemswhich canmeet practical solutions of such applications. The 13th IAPR Conference on Machine Vision Applications, MVA2013, was held fromMay 20 through 23, 2013 at the Suzaku Campus, Ritsumeikan University, co-sponsored

Computer simulation program for medium-energy ion scattering and Rutherford backscattering spectrometry

A computer simulation program for ion scattering and its graphical user interface (MEISwin) has been developed. Using this program, researchers have analyzed medium-energy ion scattering and Rutherford backscattering spectrometry at Ritsumeikan University since 1998, and at Rutgers University since 2007. The main features of the program are as follows: (1) stopping power can be chosen from five datasets spanning several decades (from 1977 to 2011), (2) straggling can be chosen from two datasets, (3) spectral shape can be selected as Gaussian or exponentially modified Gaussian, (4) scattering cross sections can be selected as Coulomb or screened, (5) simulations adopt the resonant elastic scattering cross section of 16O(4He, 4He)16O, (6) pileup simulation for RBS spectra is supported, (7) natural and specific isotope abundances are supported, and (8) the charge fraction can be chosen from three patterns (fixed, energy-dependent, and ion fraction with charge-exchange parameters for medium-energy ion scattering). This study demonstrates and discusses the simulations and their results.

The promotion of peace education through guides in peace museums. A case study of the Kyoto Museum for World Peace, Ritsumeikan University

This paper focuses on how peace education at a peace museum is promoted by a volunteer guide service for visitors. Peace museums are places where many materials related to war and peace history are on display. To support the learning experience of museum visitors, many peace museums in Japan provide a volunteer guide service. The Kyoto Museum for World Peace, Ritsumeikan University, started such a service more than 20 years ago. A citizens’ group, called Friends for Peace, is in charge of the museum guide activities in cooperation with the museum. This article explains the purposes and nature of the service, and also reports on a survey of similar services offered by other peace museums in Japan.

A Participatory Evacuation Map Making Towards Sustainable Urban Heritage Kotagede, Yogyakarta

This research aims at development of Participatory Evacuation Map Making (PEMM) for Kotagede, Yogyakarta – Indonesia. The research area is one of an important cultural heritage sites in Indonesia which is subjected towards earthquake hazard. The preliminary observation revealed that the area is a densely populated area, which characterized by dense wooden building structure, narrow street and minimum information of evacuation route which increase their vulnerability potentials. This leads to the idea of developing the PEMM to improve their awareness and preparedness during disaster events and creates sustainable condition for local livelihood security. The method develops within this research is actually a lesson learn from Ritsumeikan University, that has developed CSR for integration disaster management into heritage sites at Kyoto Prefecture. Their CSR covers several activities such as developing disaster information via vending machine and tourism map. Since Yogyakarta and Kyoto are engaged in “Sister City Development Program”, hereafter Universitas Gadjah Mada tries to do similar thing. Map making is an alternative prior to community experience in map making is rather frequent compare to vending machine habit. The preliminary finding of this research indicates that the Kotagede community has been involved in several map making activity, such as “Green Map” and “Rehabilitation Sites Map”. However, they have not yet any experience to create any map which includes information such as evacuation route, fire extinguisher, shelter information center and important meeting points. An improved critics from this research is to include meeting points level. As we all aware off, each meeting point have significant carrying capacity, thereby in the future a research on similar topics should add level and or category of meeting points. This is an important steppingstone for the research to conduct further research.

Quantitative proteomics reveals role of sugar in decreasing photosynthetic activity due to Fe deficiency.

1 Centre for Plant Biotechnology, Division of Biotechnology, S K University of Agricultural Sciences and Technology of Kashmir, Srinagar, India, 2 Research Laboratory for Biotechnology and Biochemistry, Kathmandu, Nepal, 3 GRADE Academy Private Limited, Birgunj, Nepal, 4 Faculty of Health and Sport Sciences and Tsukuba International Academy for Sport Studies, University of Tsukuba, Tsukuba, Japan, 5 Department of Bioinformatics, Ritsumeikan University, Shiga, Japan

Development of dispersive XAFS system for analysis of time-resolved spatial distribution of electrode reaction.

Apparatus for a technique based on the dispersive optics of X-ray absorption fine structure (XAFS) has been developed at beamline BL-5 of the Synchrotron Radiation Center of Ritsumeikan University. The vertical axis of the cross section of the synchrotron light is used to disperse the X-ray energy using a cylindrical polychromator and the horizontal axis is used for the spatially resolved analysis with a pixel array detector. The vertically dispersive XAFS (VDXAFS) instrument was designed to analyze the dynamic changeover of the inhomogeneous electrode reaction of secondary batteries. The line-shaped X-ray beam is transmitted through the electrode sample, and then the dispersed transmitted X-rays are detected by a two-dimensional detector. An array of XAFS spectra in the linear footprint of the transmitted X-ray on the sample is obtained with the time resolution of the repetition frequency of the detector. Sequential measurements of the space-resolved XAFS data are possible with the VDXAFS instrument. The time and spatial resolutions of the VDXAFS instrument depend on the flux density of the available X-ray beam and the size of the light source, and they were estimated as 1 s and 100 µm, respectively. The electrode reaction of the LiFePO4 lithium ion battery was analyzed during the constant current charging process and during the charging process after potential jumping.

Students' consciousness and behavior of an earthquake disaster prevention at Ritsumeikan University, Kyoto

Students' consciousness and behavior of an earthquake disaster prevention at Ritsumeikan University, Kyoto

A Study on the Role of Reflection and Bridge Learning in Service-Learning : Through the Survey of the "Community Service Learning" Course at Ritsumeikan University

A Study on the Role of Reflection and Bridge Learning in Service-Learning : Through the Survey of the "Community Service Learning" Course at Ritsumeikan University

Li2-X FeTiO4 As a High Capacity Cathode Material for Lithium Ion Battery

Introduction Research focusing on iron-based cathode materials for lithium ion batteries tends to favor materials that operate on the (de) intercalation of one Li per Fe atom (based on Fe2+/Fe3+redox couple); thereby imposing an intrinsic limitation on the energy density of the cathode material. To drastically enhance the energy density, intercalation materials with more than one electron per Fe atom are needed. In commonly used cathode materials, however, more than one electron reaction has not been utilized for charge-discharge reaction. For the development of cathode materials which achieve more than one electron reaction, it is essential to investigate the reaction mechanism.This study investigates reaction mechanism of more than one electron reaction in cathode materials. Li2-x FeTiO4 is selected as an appropriate model compound, as both the Fe2+/Fe3+ as well as Fe3+/Fe4+ redox couples are expected to be utilized to achieve high capacity. The possibility of de (intercalation) of two lithiums from the spinel-type Li2-x FeTiO4 is examined and the mechanism underlying the Li+ (de) insertion mechanism in Li2-x FeTiO4is discussed. Experimental Spinel-type LiFeTiO4 was synthesized via the conventional solid state ceramics route. Electrodes prepared from this material were examined in two-electrode coin-type cells, using lithium metal as a counter electrode. Electrodes were prepared from LiFeTiO4 to which carbon black was added and ball-milled at 400 rpm for 6 hours. Polytetrafluoroethylene (PTFE) binder was thereafter added. The weight ratio of LiFeTiO4, carbon black and PTFE was 6:3:1. The electrolyte used was a 1 M solution of LiClO4 in ethylene carbonate / diethyl carbonate. Initial lithium extraction from LiFeTiO4 was carried out based on the capacity of one lithium per Fe atom. Cells were then cycled between 1.6V and 4.2V at various current densities. The electrochemical measurements were conducted at 55.0oC. X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) measurements were conducted at SPring-8 and at SR Center, Ritsumeikan University. Results and Discussion The pristine LiFeTiO4 was characterized by Rietveld analysis. As shown in Fig. 1, all the reflections of the XRD patterns of the pristine LiFeTiO4 are fully indexed to a cubic structure (space group Fd3m). The rietveld analysis shows that all cations are randomly distributed on the tetrahedral (8a) and octahedral (16d) sites. The refined lattice parameters are consistent with the previously reported values [1-3].The spinel-type LiFeTiO4 can be electrochemically delithiated below the voltage of 4.2 V, to obtain FeTiO4. The subsequent discharge and charge measurements show that a reversible capacity of about 250 mAhg-1can be obtained under C/20 rate at an average voltage of 2.5 V with good capacity retention.For the discharged and charged Li2-x FeTiO4, XRD and XAS measurements were conducted to elucidate the crystal and electronic structural changes underlying the high capacity in spinel-type LiFeTiO4. Fig. 2 shows XRD pattern of charged and discharged Li2-x FeTiO4. The spinel structure of LiFeTiO4 is maintained during both charge and discharge reaction. Additionally, changes in the lattice constants obey Vegard’s law, indicating a solid-solution behavior during the charge and discharge reaction in Li2-x FeTiO4. References M. A. Arillo, M. L. Lopez, E. Perez-Cappe, C. Pico, M. L. Veiga, Solid State Ion., 107, 307-312 (1998).M. A. Arillo, M. L. Lopez, C. Pico, M. L. Veiga, A. Jimenez-Lopez, E. Rodriguez-Castellon, J. Alloys Comp., 160-163, 317-318 (2001).M. A. Arillo, M. L. Lopez, C. Pico, M. L. Veiga, A. Jimenez-Lopez, M. L. Vega, Chem. Mater., 17, 4162-4167 (2005).

Ultrafast Energy Transfer in Chlorosome Probed by Femtosecond Pump-Probe Polarization Anisotropy

Center for Nanomaterials and Chemical Reactions, Institute for Basic Sciences (IBS), Daejeon 305-701, Korea Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea E-mail: hyotcherl.ihee@kaist.ac.kr Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan Department of Chemistry, Inha University, Incheon 402-751, Korea. E-mail: jkim5@inha.ac.kr Received September 25, 2013, Accepted October 18, 2013

The mechanism of hetero-synaptic interaction based on spatiotemporal intracellular calcium dynamics.

The mechanism of hetero-synaptic interaction based on spatiotemporal intracellular calcium dynamics.

Sustainable Disaster Risk Reduction through Effective Risk Communication Media in Parangtritis Tourism Area, Yogyakarta

Studies on disaster risk reduction are increasing to focus on people required specific needs such as children, elderly, disabled people; yet they rarely pay attention on tourists as one of the vulnerable group in tourism areas. The lack of risk communication media for tourists increases this vulnerable situation. This research aims at the development of effective risk communication media (ERCM) for Parangtritis, Yogyakarta, Indonesia. The method that develops within this research is actually a lesson learnt from Ritsumeikan University which has implemented an alternative risk communication media called “white space”. The preliminary finding of this research indicated that local residence had better perception and awareness compared to tourist although, in general, both participants were in a low level of perceiving multi-hazard danger as a real threat. Interestingly, visitors expected that tourism management should provide adequate information on multi-hazard danger and evacuation facilities to the visitors. Several risk communication media, such as brochure, radio, billboard, SAR siren and announcement from Mosque through loudspeaker have been utilized.

Constitutional Courts as Lawmakers: A Commentary on the Lecture by Prof. Dr. Rupert Scholz, 'Constitutional Court Jurisdiction between Constitutional Law and Politics Taking the German Federal Constitutional Court as an Example'

This paper was presented at the conference Mission and the Condition of the Supreme Court in the Contemporary Society organized by the Ritsumeikan University, Kyoto, Japan, July 2013.The power of judicial review is the power to declare legislation (or action by the government) unconstitutional. Courts vested with this authority are properly denominated, whether judicial review is their exclusive function, as is the case with the German Federal Constitutional Court, or whether judicial review is but one of their functions, as is the case with the Supreme Court of the United States. The basic point of judicial review is to insulate constitutional or fundamental law from the pressures of the transitory needs perceived by the immediate majority operating under the constitution. It is true, though, that constitutional courts operate within the arena of politics, and it is also true that the decisions of constitutional courts, which are sometimes quite controversial, operate within political arena and often make law. I have developed a model that may lessen some of the “political” discomfort that arises from the practice of judicial review and make it more legitimate. My model suggests that constitutional decisions should be premised on “durable principles,” by which I mean legal standards that can, by logic and analogy, be applied uniformly to a wide range of similarly situated cases. The articulation and application of those standards must be justified through a reasoned elaboration that takes into account the full sweep of constitutional text and tradition, considers the measure of evolving cultural norms, including new perspectives on established standards, and presents a fair and thorough consideration of real-world consequences. Taken together, this decisionmaking process represents an act of creation, but does so within the breadth of the existing constitution.

Improvement of cryogenic 3-dimensional observation system of soft x-ray microscope at the SR center of Ritsumeikan University

The improvements of a soft x-ray microscope beamline (BL-12) at the SR center of Ritsumeikan University are reported. A wedge-shaped slit and Si plane mirror were newly introduced. The better energy resolution was expected and the +2nd order diffraction from the CZP (1.2 nm at 2.4 nm observation) was suppressed. A new sample holding fixture allows the sample to be replaced quickly and accurately. A new sample cooling system allowed a stable cryogenic x-ray imaging.

Network-based spatial interpolation of commuting trajectories: application of a university commuting management project in Kyoto, Japan

This study presents an application of network-based spatial interpolation of student commuting trajectories from a series of origin–destination trip datasets. In particular, we incorporated multimodal public transportation networks, including bus networks, to estimate the student commuting routes. The student samples for this study were collected from an online travel diary survey conducted by Ritsumeikan University in Kyoto, Japan. The ArcGIS Network Analyst was used to construct spatial network datasets and reconstruct trajectories from the origin–destination trip dataset. In addition, line densities of estimated trajectories were calculated and displayed on maps for geovisualization. These maps helped us understand the precise locations of congestion and spatial patterns of student commuting, unlike linear representations of people’s movements that connect origins and destinations. Our study also showed that estimated trajectories can simulate quantitative impacts on travel time by promoting walking or the use of public transportation.

Development of a two-dimensional imaging system of X-ray absorption fine structure

A two-dimensional imaging system of X-ray absorption fine structure (XAFS) has been developed at beamline BL-4 of the Synchrotron Radiation Center of Ritsumeikan University. The system mainly consists of an ionization chamber for I(0) measurement, a sample stage, and a two-dimensional complementary metal oxide semiconductor (CMOS) image sensor for measuring the transmitted X-ray intensity. The X-ray energy shift in the vertical direction, which originates from the vertical divergence of the X-ray beam on the monochromator surface, is corrected by considering the geometrical configuration of the monochromator. This energy correction improves the energy resolution of the XAFS spectrum because each pixel in the CMOS detector has a very small vertical acceptance of ∼0.5 µrad. A data analysis system has also been developed to automatically determine the energy of the absorption edge. This allows the chemical species to be mapped based on the XANES feature over a wide area of 4.8 mm (H) × 3.6 mm (V) with a resolution of 10 µm × 10 µm. The system has been applied to the chemical state mapping of the Mn species in a LiMn(2)O(4) cathode. The heterogeneous distribution of the Mn oxidation state is demonstrated and is considered to relate to the slow delocalization of Li(+)-defect sites in the spinel crystal structure. The two-dimensional-imaging XAFS system is expected to be a powerful tool for analyzing the spatial distributions of chemical species in many heterogeneous materials such as battery electrodes.

Ritsumeikan University(Inside of Laboratories)

Ritsumeikan University(Inside of Laboratories)

Time, Politics and Homelessness in Contemporary Japan

This paper examines heterotopias of homelessness in contemporary Japan. Against received claims about a shift from a social to a post-social form of politics, the paper draws attention to distinct temporal horizons that shape statist and precarious political subjectivities at sites of economic abandonment, complicating generalizations about the demise of the social and the shift to new (post-representational) political practices in neoliberal Japan. In contrast to the politics of representation that continue to mobilize statist social imaginaries around advocacy and care for the homeless, political heterotopias of homelessness index a critical refusal of hegemonic interpellations of home and home-coming. In an effort to expand understanding of the political in Japan, the paper draws attention to the multiple temporalities constitutive of the social space of homelessness. In so doing, it seeks to make visible fugitive forms of political subjectivities beyond statist and neoliberal enclosure, and contribute more broadly to a critical discourse on the nature of politics in contemporary Japan. This paper examines heterotopias of homelessness in contemporary Japan.1 Against received claims about a shift from social to ‘post-social’ forms of politics, the paper draws attention to distinct temporal horizons that shape statist and precarious political subjectivities at sites of economic abandonment, complicating generalizations about the demise of the social and the move to new (post-representational) political practices in neoliberal Japan. In contrast to the politics of representation that continue to mobilize statist social imaginaries around advocacy and care for the homeless, political heterotopias of homelessness voice a critical refusal of hegemonic interpellations of home and home-coming. In an effort to expand understanding of the political in Japan, the paper draws attention to the multiple temporalities constitutive of the social space of homelessness. In so doing, it seeks to make visible fugitive forms of political subjectivities beyond statist and neoliberal enclosure, and contribute more broadly to a critical discourse on the nature of politics in 1 I am grateful to Reiko Gotoh and Paul Dumouchel for the invitation to give a Keynote address at a conference in Ritsumeikan University in 2011 that provided the occasion for first developing a paper on ‘Home and Homelessness in Japan.’ My thanks also to Mustapha Kamal Pasha for careful reading and constructive critique of the argument pursued here.