Tokyo, Japan
Tokyo, Japan

Kogakuin University is a private university in Shinjuku, Tokyo, Japan. The predecessor of the school initially named "Koshu Gakko" which is one of the oldest private engineering schools in Japan, was founded in 1887 by educator and politician, The President of Tokyo Imperial University's President Koki Watanabe and other professors of Tokyo Imperial University.The Koshu Gakko was an evening school and it had civil, mechanical, electric, architecture, ship building, mining, metallurgical, and chemical engineering courses since it established. In 1928. the school was renamed "Kogakuin" which means "Institute of Engineering" or "Institute of Technology" in Japanese.In 1949, the school was chartered as a 4-year university. In 1964, the school had master's course and in 1966 it had doctorate course in the graduate school. Wikipedia.


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Furukawa M.,Kogakuin University
International Journal of Heat and Mass Transfer | Year: 2017

In response to technical claims that troubled nuclear reactors be safely cooled in a short period, this study discovers new merits in the so-called dream pipe which can be a kind of forced oscillatory heat pipe. Introduced are not capillary-tube-bundled dream pipes with sinusoidally vibrating mechanical shakers but parallel-plate-channeled ones with electromagnetic-driven pulse-width-modulating oscillators. Governing momentum-and-energy equations thus become quite different from those used in traditional dream pipes. An extended variational technique based on the Laplace-transform Ritz method is applied to solve the non-steady, three-dimensional partial differential equations. Possible velocity-and-temperature profiles are derived to find the effective thermal diffusivity and the tidal displacement, which are combined to yield two performance indexes for the convenience. Those two are theoretically and numerically compared with the analysis results of Watson and of Kurzweg to demonstrate that ours are acceptable. Numerical computations are made to graphically show the heat diffusive capacity of the proposed new-style dream pipes and then to present design specifications for them. © 2016 Elsevier Ltd


News Article | December 6, 2016
Site: spaceref.com

Researchers using the Atacama Large Millimeter/submillimeter Array (ALMA) have, for the first time, achieved a precise size measurement of small dust particles around a young star through radio-wave polarization. ALMA's high sensitivity for detecting polarized radio waves made possible this important step in tracing the formation of planets around young stars. Astronomers have believed that planets are formed from gas and dust particles, although the details of the process have been veiled. One of the major enigmas is how dust particles as small as 1 micrometer aggregate to form a rocky planet with a diameter of 10 thousand kilometers. Difficulty in measuring the size of dust particles has prevented astronomers from tracing the process of dust growth. Akimasa Kataoka, a Humboldt Research Fellow stationed at Heidelberg University and the National Astronomical Observatory of Japan, tackled this problem. He and his collaborators have theoretically predicted that, around a young star, radio waves scattered by the dust particles should carry unique polarization features. He also noticed that the intensity of polarized emissions allows us to estimate the size of dust particles far better than other methods. To test their prediction, the team led by Kataoka observed the young star HD 142527 with ALMA and discovered, for the first time, the unique polarization pattern in the dust disk around the star. As predicted, the polarization has a radial direction in most parts of the disk, but at the edge of the disk, the direction is flipped perpendicular to the radial direction. Comparing the observed intensity of the polarized emissions with the theoretical prediction, they determined that the size of the dust particles is at most 150 micrometers. This is the first estimation of the dust size based on polarization. Surprisingly, this estimated size is more than 10 times smaller than previously thought. "In the previous studies, astronomers have estimated the size based on radio emissions assuming hypothetical spherical dust particles," explains Kataoka. "In our study, we observed the scattered radio waves through polarization, which carries independent information from the thermal dust emission. Such a big difference in the estimated size of dust particles implies that the previous assumption might be wrong." The team's idea to solve this inconsistency is to consider fluffy, complex-shaped dust particles, not simple spherical dust. In the macroscopic view, such particles are indeed large, but in the microscopic view, each small part of a large dust particle scatters radio waves and produces unique polarization features. According to the present study, astronomers obtain these "microscopic" features through polarization observations. This idea might prompt astronomers to reconsider the previous interpretation of observational data. "The polarization fraction of radio waves from the dust disk around HD 142527 is only a few percent. Thanks to ALMA's high sensitivity, we have detected such a tiny signal to derive information about the size and shape of the dust particles," said Kataoka. "This is the very first step in the research on dust evolution with polarimetry, and I believe the future progress will be full of excitement." Reference: "Millimeter Polarization Observation of the Protoplanetary Disk around HD 142527," A. Kataoka et al., 2016 Nov. 10, Astrophysical Journal Letters [http://iopscience.iop.org/article/10.3847/2041-8205/831/2/L12, preprint: https://arxiv.org/abs/1610.06318]. The research team members are Akimasa Kataoka (Humboldt Research Fellowship for Postdoctoral Researchers / Heidelberg University / National Astronomical Observatory of Japan / former Postdoctoral Fellowship for Research Abroad at Japan Society for Promoting Science), Takashi Tsukagoshi (Ibaraki University), Munetake Momose (Ibaraki University), Hiroshi Nagai (National Astronomical Observatory of Japan), Takayuki Muto (Kogakuin University), Cornelis P. Dullemond (Heidelberg University), Adriana Pohl (Heidelberg University / Max Planck Institute for Astronomy), Misato Fukagawa (Nagoya University), Hiroshi Shibai (Osaka University), Tomoyuki Hanawa (Chiba University), Koji Murakawa (Osaka Sangyo University) This research was supported by a Grant-in-Aid from the Japan Society for the Promotion of Science and the Ministry of Education, Culture, Sports, Science and Technology, Japan (No. 23103004, 15K17606, 26800106). The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA. Please follow SpaceRef on Twitter and Like us on Facebook.


Yoshimura F.,Hokkaido University | Tanino K.,Hokkaido University | Miyashita M.,Hokkaido University | Miyashita M.,Kogakuin University
Accounts of Chemical Research | Year: 2012

Zoanthamine alkaloids, isolated from organisms in the Zoanthus genus, constitute a distinctive family of marine metabolites. These molecules exhibit a broad spectrum of unique biological properties. For example, norzoanthamine inhibits interleukin-6, the key mediator of bone resorption in osteoporosis, providing a promising drug candidate for a disease that affects more than 10 million people over age 50 in the United States. In addition, these natural products are characterized by a densely functionalized heptacyclic framework, as exemplified by the structures of zoanthamine, norzoanthamine, and zoanthenol, which makes them extremely attractive targets for chemical synthesis. Prior to our first total synthesis of norzoanthamine in 2004, the densely functionalized and complex stereostructures of the zoanthamine alkaloids had impeded synthetic studies of these molecules. In this Account, we describe our synthetic approach toward the total synthesis of zoanthamine alkaloids, focusing on how we overcame various synthetic challenges.At the beginning of our synthetic studies, we aimed to develop an efficient route that was flexible enough to provide access to several members of the family while allowing the synthesis of various analogues for biological testing. Our first project was the total synthesis of norzoanthamine, and we established an efficient synthetic route based on a novel strategy involving the following key features. First, we used a sequential three-component coupling reactions and subsequent photosensitized oxidation of a furan moiety to synthesize the precursor for the key intramolecular Diels-Alder reaction. Second, the key intramolecular Diels-Alder reaction constructed the ABC-ring carbon framework bearing two adjacent quaternary asymmetric carbon atoms at the C12 and C22 positions in a single stereoselective step. Third, we installed the third quaternary asymmetric carbon center at the C9 position by an intramolecular acylation of a keto alcohol followed by successive O-methylation and C-methylation reactions with complete stereoselectivity. Through the exploitation of a deuterium kinetic isoptope effect, we then efficiently synthesized the alkyne segment. Next, a coupling reaction between the alkyne segment and the amino alcohol segment and several subsequent synthetic transformations afforded the bis-aminoacetalization precursor. Finally, bis-aminoacetalization reactions carried out in one-pot constructed the DEFG-ring system and culminated in the total synthesis of norzoanthamine. Our synthetic route to norzoanthamine also allowed access to other zoanthamine alkaloids from a common synthetic intermediate, by way of stereoselective introduction of the C19 methyl group for zoanthamine, and isoaromatization for construction of the aromatic A-ring in zoanthenol. The chemistry described here not only allowed us to overcome formidable synthetic challenges but also opened a completely chemical avenue to naturally occurring zoanthamine alkaloids and their synthetic derivatives. © 2012 American Chemical Society.


Kanemura S.,University of Toyama | Machida N.,University of Toyama | Shindou T.,Kogakuin University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

We propose a simple model to explain neutrino mass, dark matter and baryogenesis based on the extended Higgs sector which appears in the low-energy effective theory of a supersymmetric gauge theory with confinement. We here consider the SU(2)H gauge symmetry with three flavours of fundamental representations which are charged under the standard SU(3)C×SU(2)L×U(1)Y symmetry and a new discrete Z2 symmetry. We also introduce a Z2-odd right-handed neutrino superfield in addition to the standard model matter superfields. The low-energy effective theory below the confinement scale contains the Higgs sector with fifteen composite superfields, some of which are Z2-odd. When the confinement scale is of the order of ten TeV, electroweak phase transition can be sufficiently of first order, which is required for successful electroweak baryogenesis. The lightest Z2-odd particle can be a new candidate for dark matter, in addition to the lightest R-parity odd particle. Neutrino masses and mixings can be explained by the quantum effects of Z2-odd fields via the one-loop and three-loop diagrams. We find a benchmark scenario of the model, where all the constraints from the current neutrino, dark matter, lepton flavour violation and LHC data are satisfied. Predictions of the model are shortly discussed. © 2014 The Authors.


Konishi K.,Kogakuin University
ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings | Year: 2012

This paper provides an alternating optimization algorithm for large-scale matrix rank minimization problems and its parallel implementation on GPU. The matrix rank minimization problem has a lot of important applications in signal processing, and several useful algorithms have been proposed. However most algorithms cannot be applied to a large-scale problem because of high computational cost. This paper proposes a null space based algorithm, which provides a low-rank solution without computing inverse matrix nor singular value decomposition. The algorithm can be parallelized easily without any approximation and can be applied to a large-scale problem. Numerical examples show that the algorithm provides a low-rank solution efficiently and can be speed up by parallel GPU computing. © 2012 IEEE.


Thanks to the recent developments, the superconducting cables using high-temperature superconducting (HTS) materials are now expected to reduce feeding losses in the power supply network for DC electric railways. However, by connecting the HTS cables with the normal conducting wires electrically, heat intrusion is inevitable; to suppress heat intrusion to an acceptable level, interconnection becomes a large and costly installation. This means that the use of HTS cables as the replacement for normal conducting feeder wires in the DC railway feeding network is unrealistic because of the need for frequent interconnections between the feeder and contact wires. By combining the results obtained by a number of cases of multi-train simulation and a preliminary estimate of the refrigeration losses, the author shows that, by using HTS cables to replace some of the feeding substations, rather than the feeder wires, the introduction of HTS cables in the feeding network of DC electric railways may have positive effects of saving energy. © 2012 The Institution of Engineering and Technology.


Furukawa M.,Kogakuin University
Journal of Heat Transfer | Year: 2014

Various ways developed so far in modeling oscillating/pulsating heat pipes (OHPs/PHPs) are briefly reviewed to find which way would be serviceable for design purposes and also be helpful to mathematically plainly describe oscillatory/circulatory motions of the charged working fluid. A selected way basically follows Ma's approach but a theoretically new attempt is made to derive the oscillation angular frequency ratio from two differently represented expressions of the oscillation velocity. A two-phase flow and evaporative/condensing heat transfer analysis is then carried out to get the wave equation of pressure oscillation. Finally obtained are closed-form algebraic expressions, providing us with convenient means of predicting the oscillation frequency- and-amplitude and the wave velocity. To demonstrate the applicability of those expressions, numerical comparisons are extensively done between our predictions and many other ones. © 2014 by ASME.


Furukawa M.,Kogakuin University
Journal of Heat Transfer | Year: 2011

A novel type of so-called dream pipe is introduced hoping for the high-efficiency heat removal. Unlike traditional types with mechanical shaker, this one fits up an inverse-piezoelectric-cells embedded thin disk coupled with ac power to cause oscillatory pipe flows. A theoretical approach is adopted to comprehensively describe thermal characteristics of that new device. With a view to obtaining more practical expressions than accepted before, the Galerkin method based on the variational principle is used to solve governing partial differential equations. The induced tidal displacement and the relative increase of thermal diffusivity are expressed in reduced algebraic form. Also presented are design formulas defining the specific driving power and the specific number of required tubes. Concerning the effective thermal diffusivity, the author's predictions are fairly well consistent with exact ones deduced from Watson's expression. Ratios of the two are linearly regressed to a cubic equation applicable to the frequency range from 0.5 Hz to 6.0 Hz. Recommendable coefficient values are listed in the table. Possible combinations of four fluids of interest and seven levels of the applied ac voltage are considered in a parametric study. Numerical results are graphically shown in the figures for discussion on the feasibility. © 2011 American Society of Mechanical Engineers.


Patent
Kogakuin University and Otsuka Pharmaceutical Factory Inc. | Date: 2012-06-06

Provided is a metal colloid having higher visibility and higher sensitivity than a gold colloid and a Au-core Pt-shell composite colloid and suitable as a labeling agent for use in a test such as an immunoassay. An alloyed Au/Pt composite colloid formed by mixing a gold salt and a platinum salt with at least one reducing agent selected from the group consisting of an amino acid and a derivative thereof, an oligopeptide and a derivative thereof, and an amino sugar in the presence of an alkali, thereby reducing the gold salt and platinum salt.


Patent
Otsuka Pharmaceutical Factory Inc. and Kogakuin University | Date: 2010-07-29

Provided is a metal colloid having higher visibility and higher sensitivity than a gold colloid and a Au-core Pt-shell composite colloid and suitable as a labeling agent for use in a test such as an immunoassay. An alloyed Au/Pt composite colloid formed by mixing a gold salt and a platinum salt with at least one reducing agent selected from the group consisting of an amino acid and a derivative thereof, an oligopeptide and a derivative thereof, and an amino sugar in the presence of an alkali, thereby reducing the gold salt and platinum salt.

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