Institution
Chiba Institute of Technology
Education•Narashino, Japan•
About: Chiba Institute of Technology is a education organization based out in Narashino, Japan. It is known for research contribution in the topics: RNA & Magnet. The organization has 2663 authors who have published 4999 publications receiving 56870 citations. The organization is also known as: Chiba kōgyō daigaku & Kōa Institute of Technology.
Topics: RNA, Magnet, Robot, Coercivity, Finite element method
Papers published on a yearly basis
Papers
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Kobe University1, Japan Aerospace Exploration Agency2, Chiba Institute of Technology3, Kōchi University4, Toho University5, Centre national de la recherche scientifique6, University of Bern7, Tokyo University of Science8, University of Tokyo9, Rikkyo University10, Spanish National Research Council11, National Institute of Advanced Industrial Science and Technology12, University of Aizu13, Nagoya University14, Graduate University for Advanced Studies15, University of Liverpool16
TL;DR: An impact experiment on Ryugu is described using Hayabusa2’s Small Carry-on Impactor, which produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit, and implications for Ryugu's surface age are discussed.
Abstract: The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.
183 citations
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TL;DR: In this paper, a self-powered active vibration control system with regenerated energy was proposed, where an actuator is connected to the condenser through relay switches, which decide the direction of the electric current, and a variable resistor, which controls the amount of electric current.
181 citations
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TL;DR: In this paper, the authors proposed a model to reveal the porosity evolution from dust grains via fluffy aggregates to form planetesimals, circumventing the barriers in planetesimal formation.
Abstract: Context: In planetesimal formation theory, several barriers have been proposed, which are bouncing, fragmentation, and radial drift problems. To understand the structure evolution of dust aggregates is a key in the planetesimal formation. Dust grains become fluffy by coagulation in protoplanetary disks. However, once they become fluffy, they are not sufficiently compressed by collisional compression to form compact planetesimals. Aims: We aim to reveal the pathway of the dust structure evolution from dust grains to compact planetesimals. Methods: Using the compressive strength formula, we analytically investigate how fluffy dust aggregates are compressed by static compression due to ram pressure of the disk gas and self gravity of the aggregates in protoplanetary disks. Results: We reveal the pathway of the porosity evolution from dust grains via fluffy aggregates to form planetesimals, circumventing the barriers in planetesimal formation. The aggregates are compressed by the disk gas to the density of 10^{-3} g/cm^3 in coagulation, which is more compact than the case with collisional compression. Then, they are compressed more by self gravity to 10^{-1} g/cm^3 when the radius is 10 km. Although the gas compression decelerate the growth, they grow enough rapidly to avoid the radial drift barrier when the orbital radius is < 6 AU in a typical disk. Conclusions: We propose fluffy dust growth scenario from grains to planetesimals. It enables the icy planetesimal formation in a wide range beyond the snowline in protoplanetary disks. This result proposes a concrete initial condition of planetesimals for the later stages of the planet formation.
177 citations
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TL;DR: In this paper, the mechanical properties of poly(3-hydroxybutyrate- co-3hydroxyvarelate) (PHBV) composites, reinforced with short abaca fibers prepared by melt mixing and subsequent injection molding, were investigated and compared with PHBV composites reinforced with glass fiber (GF).
Abstract: The mechanical properties of poly(3-hydroxybutyrate- co-3-hydroxyvarelate) (PHBV) composites, reinforced with short abaca fibers prepared by melt mixing and subsequent injection molding, were investigated and compared with PHBV composites reinforced with glass fiber (GF). The influences of fiber length, fiber content, and surface treatment of the natural fiber on the mechanical properties were evaluated. Regarding fiber length, the tensile properties had a maximum at a fiber length of about 5 mm. The flexural properties of the PHBV/abaca composite were improved by the surface treatment of abaca with butyric anhydride and pyridine for 5 h because of the increase of interfacial adhesiveness between the matrix polyester and the surface-esterified fiber, as is obvious from the SEM micrographs. The flexural and tensile properties of PHBV/treated abaca composite were comparable to those of PHBV/GF composite, except for tensile modulus, compared with the same weight fraction of fiber. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 129–138, 2002
176 citations
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TL;DR: In this article, the authors examined how the collisional growth efficiency of dust aggregates with different impact parameters depends on the size and the mass ratio of colliding aggregates and showed that high values for the impact parameter are important and that the average growth efficiency averaged over the impact parameters does not depend on the aggregate size, although the growth efficiency for nearly head-on collisions increases with size.
Abstract: Context. Collisional growth of dust aggregates is an essential process in forming planetesimals in protoplanetary disks, but disruption through high-velocity collisions (disruption barrier) could prohibit the dust growth. Mass transfer through very different-sized collisions has been suggested as a way to circumvent the disruption barrier. Aims. We examine how the collisional growth efficiency of dust aggregates with different impact parameters depends on the size and the mass ratio of colliding aggregates. Methods. We used an N-body code to numerically simulate the collisions of different-sized aggregates. Results. Our results show that high values for the impact parameter are important and that the growth efficiency averaged over the impact parameter does not depend on the aggregate size, although the growth efficiency for nearly head-on collisions increases with size. We also find that the averaged growth efficiency tends to increase with increasing mass ratio of colliding aggregates. However, the critical collision velocity, above which the growth efficiency becomes negative, does not strongly depend on the mass ratio. These results indicate that icy dust can grow through high-velocity offset collisions at several tens of ms −1 , the maximum collision velocity
171 citations
Authors
Showing all 2681 results
Name | H-index | Papers | Citations |
---|---|---|---|
Shigeyuki Yokoyama | 107 | 1113 | 49711 |
Hiroyuki Shimada | 88 | 881 | 30180 |
Naoki Yamamoto | 74 | 492 | 22987 |
Kazuhito Tsukagoshi | 62 | 409 | 13609 |
Kunitada Shimotohno | 55 | 161 | 12006 |
Sahin Kaya Ozdemir | 54 | 267 | 15042 |
Hiroshi Kimura | 54 | 308 | 11407 |
Takahiro Hiroi | 47 | 256 | 7107 |
Ryuji Tada | 45 | 195 | 6524 |
Takashi Kumasaka | 42 | 166 | 12036 |
Ichiro Hirao | 41 | 244 | 5811 |
Harald Krüger | 39 | 162 | 4830 |
Goro Komatsu | 38 | 215 | 5089 |
Kin-ichiro Miura | 38 | 220 | 7730 |
Keiji Nagatani | 37 | 220 | 5274 |