In this study, we investigated the effect of bisphosphonate on the osteoblastic differentiation of human dental stem cells (hDPSCs). In the first experiment, we evaluated the effect of bisphosphonate on the differentiation of hDPSCs into osteoblasts by alkaline phosphatase staining after culturing hDPSCs. As a result, on day 13, the osteogenic differentiation of hDPSC was suppressed at 5 μM in clodronate and 2 μM in zolendronate. In NBP, osteogenic differentiation is more suppressed. In second experiment, cytotoxicity and proliferation test, the cell proliferation (examined by MTT assay) was more suppressed as the concentrations of zolendronate were larger than those of alendronate and clodronate. Western blotting, a third experiment, was found that AKT phosphorylation was inhibited in cell signaling proteins involved in cell proliferation inhibition and death by bisphosphonate concentration. In human dental stem cells, bisphosphonates inhibit osteoblast differentiation, and this phenomenon is clearly observed in NBPs (zolendronate), and it has been found that it is related to AKT phosphorylation of cell signaling proteins.

In the present study, fast isothermal stabilization processes for rayon precursor fabrics were performed at 350℃ and 400℃ within 3 minutes and the chemical and physical characteristics of the stabilized fabrics were investigated. In addition, rayon precursor fabrics were pre-treated with three different phosphorous-based flame retardants and then stabilized. The effect of flame retardants on the chemical composition, thermal shrinkage, weight change, thermal stability and XRD results was examined, comparing with those of the precursor fabrics. The result showed that the stabilization of rayon fabrics was most effective as the stabilization temperature was 350℃, the stabilization time was 3 min, and the pre-treatment with phosphoric acid of 1 vol%. The carbon contents of stabilized rayon fabrics were increased with increasing stabilization temperature and time, whereas the oxygen contents were decreased. Also, it is likely that the pre-treatment with phosphoric acid plays a role in retarding the change of chemical structure of rayon fabric. The XRD result was quite consistent with the result showing the effect of phosphoric acid on the chemical composition, thermal shrinkage and weight reduction of rayon fabric.

In this work, we employed an electroless nickel plating on glass fibers in order to enhance the electric conductivity of fibers. And the effects of metal content and plating time on the conductivity of fibers were investigated. From the results, island-like metal clusters were found on the fiber surfaces in initial plating state, and perfect metallic layers were observed after 10 min of plating time. The thickness of metallic layers on fiber surfaces was proportion to plating time, and the electric conductivity showed similar trends. The nickel cluster sizes on fibers decreased with increasing plating time, indicating that surface energetics of the fibers could become more homogeneous and make well-packed metallic layers, resulting in the high conductivity of Ni/glass fibers.

In this study, commercially available pitch-based carbon fibers of general grade were post-heat-treated using a boxtype high temperature furnace at 1800℃, 2000˚, 2200℃, and 2400℃, respectively. The fundamental characteristics of each heat-treated carbon fibers were investigated in terms of chemical composition, morphology, thermal stability, X-ray diffraction, single filament tensile test, and electrical resistivity. The result showed that the fiber properties were significantly influenced by the post-heat-treatment, indicating the greater effect with increasing treatment temperature. The carbon contents, thermal stability, and tensile properties of the carbon fibers used here were further increased by the post-heat-treatment, whereas the d-spacing between graphene layers and the electrical resistivity were reduced with increasing post-heat-treatment temperature.

최근 전자거래가 B2C에서 B2B로 변화하는 추세에 따라 협업적인 가상환경에서 협업적 제품 거래(CPC, Collaborative Product Commerce)는 기업간 전자거래의 한 부분으로 자리 잡아 가고 있다. 이에 따라 본 논문에서는 진정한 기업간 전자거래 실현을 위하여 제품의 라이프사이클에 관련된 글로벌 기업 및 고객이 제품정보 및 협업 프로세스를 공유하고, 응용시스템을 통합함으로써 기업간의 협동 작업을 지원하는 협업적 제품거래 통합 프레임워크를 제안한다. 제안한 프레임워크의 느슨한 구조의 통합을 위해서는 XML SOAP, WSDL 및 UDDI 기술과 같은 Web Service 기술을 기반으로 하고, 이러한 웹 서비스 기반하에 각기 다른 언어로 작성된 여러 플랫폼 상에서 실행되는 각 기업의 이 기종 어플리케이션들이 인터넷상에서 실시간 프로그램 방식으로 상호작용할 수 있도록 CPC 통합 프레임워크를 구현 하였다.