Nanometric Positioning Over a One-Millimeter Stroke Using a Flexure Guide and Electromagnetic Linear Motor

Fukada, Shigeo,Nishimura, Kentaro Korean Society for Precision Engineering 2007 International Journal of Precision Engineering and Vol.8 No.2

In this study, we investigated experimentally the potential of a planer positioning mechanism with three degrees of freedom using a flexure guide and an electromagnetic linear motor. The goal was to produce a multi-axis positioning system with nanometric resolution over a 1-mm stroke. An $X-Y-\theta$ stage was designed based on previous results from a single-axis prototype and was constructed with a flexure guide mechanism and voice coil motor type linear actuators. We examined the necessity of a driving method and control system to ensure high resolution for multi-axis positioning. Experiments were conducted to evaluate the performance, and the results confirmed the mechanism's potential; fine point-to-point (PTP) positioning was achieved over a 1-mm stroke, with a resolution of 2 nm for translation in X-Y and 0.01 asec for yaw in $\theta$.

Experiment to Recover Tritium from Li-Pb Blanket and Understanding Chemistry of the Li₁₇Pb₈₃—H System

Fukada, Satoshi,Kinjyo, Mao,Oda, Takuji,Nishikawa, Terunori,Katayama, Kadzunari AMERICAN NUCLEAR SOCIETY, INC. 2017 FUSION SCIENCE AND TECHNOLOGY Vol.72 No.3

Nanometric Positioning Over a One-Millimeter Stroke Using a Flexure Guide and Electromagnetic Linear Motor

Shigeo Fukada,Kentaro Nishimura 한국정밀공학회 2007 International Journal of Precision Engineering and Vol.8 No.2

In this study, we investigated experimentally the potential of a planer positioning mechanism with three degrees of freedom using a flexure guide and an electromagnetic linear motor. The goal was to produce a multi-axis positioning system with nanometric resolution over a 1-㎜ stroke. An X-Y-θ stage was designed based on previous results from a single-axis prototype and was constructed with a flexure guide mechanism and voice coil motor type linear actuators. We examined the necessity of a driving method and control system to ensure high resolution for multi-axis positioning. Experiments were conducted to evaluate the performance, and the results confirmed the mechanism's potential: fine point-to-point (PTP) positioning was achieved over a 1-㎜ stroke, with a resolution of 2 ㎚ for translation in X- Y and 0.01 asec for yaw in θ.

Corrosion Damage Assessment Method for Steel Guardrail Post Roots

Saiji Fukada,Chen Xu,Takuya Mizuno,Minobu Aoyama 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.4

Steel guardrail posts are typically used on the highway system of Japan, but these can experience the corrosion damage at their root near the road surface. This damage may be particularly severe in the seaside areas or regions that experience cold weather and employ salt as a deicing agent. Therefore, this study aimed to develop a non-destructive way of estimating the extent of corrosion in the guardrail post roots. Particularly, 11 test specimens were parametrically designed to investigate the efficiency of using the impact vibration mode to assess the corrosion damage. The corrosion angle, range and thickness at the post root were the main parameters. Meanwhile, a parametric FEM analysis was executed as well to analyze the vibration behavior, the stiffness and the load-carrying capacity. In general, the study reveals that the high-order vibration modes are sensitive to the corrosion damage at the guardrail post roots, and based on this, an impact vibration method for assessing the corrosion damage was proposed.

Learning about Water in a Japanese Kindergarten (Yochien): Two Approaches to Teaching Science

Shozo Fukada,Manabu Sumida,Masaru Masukagami,Chizue Sakata 한국유아교육학회 2005 INTERNATIONAL JOURNAL OF EARLY CHILDHOOD EDUCATION Vol.11 No.2

Exercise/Resistance Training and Muscle Stem Cells

So-ichiro Fukada,Ayasa Nakamura 대한내분비학회 2021 Endocrinology and metabolism Vol.36 No.4

Skeletal muscle has attracted attention as endocrine organ, because exercise-dependent cytokines called myokines/exerkines are released from skeletal muscle and are involved in systemic functions. While, local mechanical loading to skeletal muscle by exerciseor resistance training alters myofiber type and size and myonuclear number. Skeletal muscle-resident stem cells, known as musclesatellite cells (MuSCs), are responsible for the increased number of myonuclei. Under steady conditions, MuSCs are maintained in amitotically quiescent state but exit from that state and start to proliferate in response to high physical activity. Alterations in MuSCbehavior occur when myofibers are damaged, but the lethal damage to myofibers does not seem to evoke mechanical loading-dependent MuSC activation and proliferation. Given that MuSCs proliferate without damage, it is unclear how the different behaviors ofMuSCs are controlled by different physical activities. Recent studies demonstrated that myonuclear number reflects the size of myofibers; hence, it is crucial to know the properties of MuSCs and the mechanism of myonuclear accretion by MuSCs. In addition, theelucidation of mechanical load-dependent changes in muscle resident cells, including MuSCs, will be necessary for the discovery ofnew myokines/exerkines and understating skeletal muscle diseases.

The Task of Christian Education in Japan: So that each person may be called by name

Robert Mikio Fukada 한국기독교교육정보학회 2006 Journal of Christian education information tech Vol.0 No.9

Japan today is in the process of probing what her future should be, especially in the area of education. The rapid development of science and technology is affecting patterns of human relationships and a comprehensive critique is called for in both public and private education, which includes church school education. The focus of this paper is on the value of human personality and its maturation. The value and dignity of personality were introduced to Japan through Western thought, especially that of the Christian faith. In order to gain some insight into seeing the present and to search for the future of education in Japan, three persons were selected for brief examination: Motoko Hani, the founder of Jiyu Gakuen; Toyohiko Kagawa, an evangelist and social movement leader; and Joseph Hardy Neesima, the founder of Doshisha University. These were Christians who left an impact not only on Christian education and the Church but on Japanese society as a whole through the graduates of their schools and, in Kagawa’s case, the people who were exposed to visions of a society of mature people. For the maturation process of persons and their personalities, a nurturing community is essential. All three of the people mentioned above, each in his/her way, strove for formation of such communities. They believed that education becomes effective in process of such formation, when each participant is a significant value in the maturation of others. It is important to be careful in such a process that an institution not become an end in itself, falling into a state of institutionalism, but that it be repeatedly re-examined for its ultimate purpose.

Molecular Mechanism of Photic-Entrainment of Chicken Pineal Circadian Clock

Okano, Toshiyuki,Fukada, Yoshitaka Korean Society of Photoscience 2002 Journal of Photosciences Vol.9 No.2

The chicken pineal gland has been used for studies on the circadian clock, because it retains an intracellular phototransduction pathway regulating the phase of the intrinsic clock oscillator. Previously, we identified chicken clock genes expressed in the gland (cPer2, cPer3, cBmal1, cBmal2, cCry1, cCry2, and cClock), and showed that a cBMALl/2-cCLOCK heteromer acts as a regulator transactivating cPer2 gene through the CACGTG E-box element found in its promoter. Notably, mRNA expression of cPer2 gene is up-regulated by light as well as is driven by the circadian clock, implying that light-dependent clock resetting may involve the up-regulation of cPer2 gene. To explore the mechanism of light-dependent gene expression unidentified in animals, we first focused on pinopsin gene whose mRNA level is also up-regulated by light. A pinopsin promoter was isolated and analyzed by transcriptional assays using cultured chicken pineal cells, resulting in identification of an 18-bp light-responsive element that includes a CACGTG E-box sequence. We also investigated a role of mitogen-activated protein kinase (MAPK) in the clock resetting, especially in the E-box-dependent transcriptional regulation, because MAPK is phospholylated (activated) in a circadian manner and is rapidly dephosphorylated by light in the gland. Both pulldown analysis and kinase assay revealed that MAPK directly associates with BMAL1 to phosphorylate it at several Ser/Thr residues. Transcriptional analyses implied that the MAPK-mediated phosphorylation may negatively regulate the BMAL-CLOCK-dependent transactivation through the E-box. These results suggest that the CACGTG E-box serves not only as a clock-controlled element but also as a light-responsive element.

Hydrogen adsorption on TiO₂ surfaces

Naoki NAGATSUKA,Keisuke FUKADA,Kotaro TAKEYASU,Masuaki MATSUMOTO,Katsuyuki FUKUTANI 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

A Novel Phototransduction Pathway in the Pineal Gland and Retina

Okano, Toshiyuki,Kasahara, Takaoki,Fukada, Yoshitaka Korean Society of Photoscience 2002 Journal of Photosciences Vol.9 No.2

Light is a major environmental signal for entrainment of the circadian clock, but little is known about the phototransduction pathway triggered by light-activation of photoreceptive molecule(s) responsible for the phase shift of the clock in vertebrates. The chicken pineal gland and retina contain the autonomous circadian oscillators together with the photic entrainment pathway, and hence they provide useful experimental model for the clock system. We previously demonstrated the expression and light-dependent activation of rod-type transducin $\alpha$-subunit (Gtl$\alpha$) in the chicken pineal gland. It is unlikely, however, that the pineal Gt$_1$$\alpha$ plays a major role in the photic entrainment, because the light-induced phase shift is unaffected by bloking the signaling function of Gt$_1$$\alpha$. Here, we show the expression of G 11 $\alpha$, an $\alpha$-subunit of another heterotrimeric G-protein, in the chicken pineal gland and retina by cDNA cloning, Northern blot and Western blot analyses. GIl$\alpha$-immunoreactivity was colocalized with pinopsin in the chicken pineal cells and it was found predominantly at the outer segments of photoreceptor cells in the retinal sections, suggesting functional coupling of G11 $\alpha$ with opsins in the both the tissues. By coimmunoprecipitation experiments using the retina, we showed the light- and GTP-dependent interaction between rhodopsin and G11 $\alpha$. Upon ectopic expression of a Gq/ 11-coupled receptor in cultured pineal cells, pharmacological (non-photic) activation of endogenous G11 induced phase-dependent phase shifts of the melatonin rhythm in a manner very similar to the effect of light. These results suggested opsin-G11 pathway contributing to the photic entrainment of the circadian clock.