Hiroshi Komatsugawa

Nonequilibrium phase diagram of a polydisperse system: A molecular dynamics study

We investigate the structural changes of a polydisperse system undergoing an oscillator shear flow by use of a nonequilibrium molecular dynamics simulation. The nonequilibrium phase diagrams are investigated in the space of the amplitude of the shear rate and the number density at several polydispersities. At small polydispersity, phase changes to two types of layered structures are observed and this phenomenon is similar to that in the monodisperse case. With increase of polydispersity, the system becomes disordered, and an amorphous phase is observed in the equilibrium state. Furthermore, we investigate the size dependence of structural changes in the polydisperse system. In consequence, we observe less of a dependence on the phase changes in our oscillatory shear case.

Analysis of mode size transformation with a tapered directional coupler

A simple tapered directional coupler with a five-layered structure is employed for mode conversion between a single-order and higher-order modes. We investigate coupling from higher-order modes to a single-order field theoretically and experimentally. As a result, we confirm that the first two modes in the tapered waveguide are coupled with a single-order mode in another waveguide by computer simulation using the beam propagation method. Furthermore, we fabricated the actual device and observed the streak patterns of the first three modes.

Evaluation of Educational Effect of Problem-Posing System in Nursing Processing Study

The nursing processing study is generally difficult, because it is important for nursing college students to understand knowledge and utilize it. We have developed an integrated system to understand, utilize, and share knowledge. We added a problem-posing function to this system, and expected that students would deeply understand the nursing processing study through the new system. This system consisted of four steps: create a problem, create an answer input section, create a hint, and verification. Nursing students created problems related to nursing processing by this system. When we gave a lecture on the nursing processing for second year students of A university, we tried to use the creating problem function of this system. We evaluated the effect by the number of problems and the contents of the created problem, that is, whether the contents consisted of a lecture stage or not. We also evaluated the correlation between those and regular examination and report scores. We derived the following: 1. weak correlation between the number of created problems and report score (r=0.27), 2. significant differences between regular examination and report scores of students who created problems corresponding to the learning stage, and those of students who created problems not corresponding to it (P<0.05). From these results, problem-posing is suggested to be effective to fix and utilize knowledge in the lecture of nursing processing theory.