Chemical Reaction between Single Hydrogen Atom and Graphene

We study chemical reaction between a single hydrogen atom and a graphene, which is the elemental reaction between hydrogen and graphitic carbon materials. In the present work, classical molecular dynamics simulation is used with modified Brenner's empirical bond order potential. The three reactions, that is, absorption reaction, reflection reaction and penetration reaction, are observed in our simulation. Reaction rates depend on the incident energy of the hydrogen atom and the graphene temperature. The dependence can be explained by the following mechanisms: (1) The hydrogen atom receives repulsive force by pi-electrons in addition to nuclear repulsion. (2) Absorbing the hydrogen atom, the graphene transforms its structure to the ``overhang'' configuration such as sp-3 state. (3) The hexagonal hole of the graphene is expanded during the penetration of the hydrogen atom.Comment: 10 pages, 9 figures. This paper was submitted to PR

Hybrid Simulation between Molecular Dynamics and Binary Collision Approximation Codes for Hydrogen injection onto Carbon Materials

Molecular dynamics (MD) simulation with modified Brenner's reactive empirical bond order (REBO) potential is a powerful tool to investigate plasma wall interaction on divertor plates in a nuclear fusion device. However, MD simulation box's size is less than several nm for the performance of a computer. To extend the size of the MD simulation, we develop a hybrid simulation code between MD code using REBO potential and binary collision approximation (BCA) code. Using the BCA code instead of computing all particles with a high kinetic energy for every step in the MD simulation, considerable computation time is saved. By demonstrating a hydrogen atom injection on a graphite by the hybrid simulation code, it is found that the hybrid simulation code works efficiently in a large simulation box.Comment: 5 pages, 5 figure

Hydrophobic Silicone Elastomer Chamber for Recording Trajectories of Motile Porcine Sperms without Adsorption

Motile porcine sperms adhere to hydrophilic materials such as glass and plastics. The adsorption of sperms to a hydrophobic poly(dimethylsiloxane) (PDMS) membrane is less compared with that to glass. We investigated the linear velocity (LV) and amplitude of lateral head displacement (ALHD) of motile porcine sperm on glass and PDMS preparations using computer-assisted sperm analysis (CASA). Significant decreases were observed in the 15-min LV (P<0.05) and ALHD (P<0.05) in motile porcine sperm on glass preparations compared with those on PDMS preparations. These differences were due to adsorption of the head and/or neck to hydrophilic substrates. Because of the elasticity of PDMS, we propose that a PDMS membrane should be used for CASA. To investigate the dynamics of motile porcine sperms with microfluidics, we do not recommend plasma treatment to bond PDMS and glass in the microchannel preparation; instead, we suggest that a PDMS molding process without plasma treatment be used for preparation of microfluidic channels

Metformin suppresses expression of the selenoprotein P gene via an AMPactivated kinase (AMPK)/FoxO3a pathway in H4IIEC3 hepatocytes

13301甲第4112号博士(医学)金沢大学博士論文本文Full 以下に掲載：The Journal of Biological chemistry 289(1) pp.335-345 2014. American Society for Biochemistry and Molecular Biology. 共著者：高山 浩昭, 御簾 博文, 岩間 久和, 近本 啓太, 斎藤 芳郎, 村尾 孝児, 寺口 敦, Fei Lan, 菊地 晶裕, 齋藤 麗奈, 田島 奈津美, 白崎 尚芳, 松郷 誠一, 宮本 謙, 金子 周一, 篁 俊

Equivalent-Circuit Model for Axisymmetric High-Temperature Superconducting Film: Application to Contactless jC Measurement System and Pellet Injection System

A high-temperature superconducting (HTS) film is used for numerous engineering devices. The analysis of the shielding current density in the HTS is essential to develop the HTS devices. By using the equivalent-circuit model (ECM) [1] , the analysis of the shielding current density becomes equivalent to solving the initial-value problem of the 1st-order ordinary differential system

Current Distribution Optimization by Using Genetic-Algorithm Based On-Off Method: Application to Pellet Injection System

The current distribution in the electromagnet is optimized by using the genetic-algorithm based on-off method so as to maximize the acceleration performance of the Superconducting Linear Acceleration (SLA) system. In the SLA system, a pellet container is accelerated by the interaction between a shielding current density and an applied magnetic field. By using the equivalent-circuit model, the distribution of the shielding current density is approximated as a set of the multiple current loops. In contrast, the current distribution in the electromagnet is represented by means of the on-off method. As the method for optimizing the current distribution in the electromagnet, two types of genetic algorithms are adopted. The results of computations show that the pellet velocity for the optimized current distribution is 1.3 times as fast as that for the homogeneous current distribution