Per- and polyfluoroalkyl substances (PFASs) have unique properties, such as water- and oil-repellency, and have been used in various materials worldwide. Recently, a stratified dipole arrays model was proposed to explain the properties of PFASs comprehensively. According to this model, the aggregate structures of PFA chains, which vary depending on the chain length, are the key to understanding the unique properties of PFASs. In this study, we performed molecular dynamics simulations of the perfluoroalkyl oligomers, CF₃(CF₂)_mCF₃, to examine the aggregate structure of the monolayer. The results show that the system has disordered structures and liquid-like behavior at m = 5 and 6, while hexagonal structures and solid-like behavior at m ≥ 8. The system with m = 7 behaved as an intermediate state between these two groups. This study reinforces the importance of PFA chain length in understanding the properties of PFASs.

In the present work, we shall explore several fundamental properties of irSIR model for the information diffusion on SNS leading an implicit analytical solution of the state variables in similar manner with SIR model for the infectious disease. From the present simulation results, it will be elucidated that there may exist an analogy between the characteristics of the final size equations for SIR and irSIR models. Then the dependence of the final non-active users derived from the final size equation on the information diffusion rate and the maximum values of the active users will be examined in detail in connection with the existence of a peak behavior of the active users. Furthermore the effect of the time-dependent information diffusion rate will be investigated from viewpoints of the final values of the non-user population as well as the profiles of the active user population on SNS. Finally we shall present an example of comparison with the practical data for the active users on SNS.

In the present work, we shall propose a simple secure communication model based on globally coupled map model with a Tent mapping by means of the chaos synchronization. In practice we will present an analytical expression for the chaotic synchronization condition and put forward a secure communication model with the multi-channel transmitted signals in general. Through some computer simulations, it will be found that the presently proposed secure model may open a worthwhile strategy to achieve a highly encryption scheme in the chaos secure communication discipline.