The sintering mechanisms of nanoscale copper powders have been investigated. A molecular dynamics (MD) simulation with the embedded-atom method (EAM) was employed for these simulations. The dimensional changes for initial-stage sintering such as characteristic lengths, neck growth, and neck angle were calculated to understand the densification behavior of copper nano-powders. Factors affecting sintering such as the temperature, powder size, and crystalline misalignment between adjacent powders have also been studied. These results could provide information of setting the processing cycles and material designs applicable to nano-powders. In addition, it is expected that MD simulation will be a foundation for the multi-scale modeling in sintering process.

This study focused on the review of the korean fire investigation system and will provide the means for having the legal investigation right. The most important thing is to give fire department a perfect legal investigation right on fire including police areas(seeking and examining the case at first stage). And it should be stated in criminal law. With the joint effort between Fire department and Police department, we can develop the reformation, enlightening programs for the arsons or fire related criminals. Through this, it systematically have to be good for fire prevention and can be helpful to enhancing professionalism of fire examination.

The objective of this study was to compare peri-implant bone formation among uncoated (UC), hydroxyapatite (HA), collagen plus hydroxyapatite (CH), and silk plus hydroxyapatite (SH) implant groups. Surface coating was applied using the aerosol deposition method. The morphology of MG63 cells on the implant surfaces were examined by scanning electron microscopy (SEM) after 8 h cultures on the each of implant groups. After 48 h cultures, MTT assay was performed to compare cell viabilities of each group. Subsequently, a total of 20 implants from each group were installed in the tibia of the rabbits. The animals were sacrificed at 6 weeks after the implant installation. The peri-implant bone formation was evaluated from the histological sections. In the SEM images, SH coating implant showed better attachment of MG63 cells to the implant surface than the other groups. It also showed adequate cell viabilities and peri-implant bone formations compared with other implant groups. From these in vitro and vivo experiments, SH coating can be a possible candidate for the surface treatment of dental implant. This study was supported by a grant from the Next-Generation BioGreen21 Program (Center for Nutraceutical & Pharmaceutical Materials no. PJ009013)