The worldwide PMA pavement is steadily increasing. Unlike straight asphalt at the specified temperature of the performance grade, PMA has little increase in complex modulus after RFTO. Even after satisfying the complex modulus of the original binder, the complex modulus after the RTFO does not satisfy the grade, so that the SBS may be over-prescribed. Unlike straight asphalt, PMA investigated the reason that the complex modulus did not increase after RTFO in this study. SBS consists of a styrene domain and a butadiene matrix. The morphology of SBS in PMA is not clear. The PMA was heat - treated to induce the formation of styrene domain and PG evaluation was carried out. As a result, we confirmed that the formation of styrene domain with aging effect changed the complex modulus after RTFO.

Intracellular reactive oxygen species(ROS) produced in a various pathologic state was known to intermediate many cellular response such as inflammation. Recently, low level light irradiation by HeNe laser used in many clinical field could improve inflammatory state by scavenging intracellular ROS through photo-detachment/dissociation process. The purpose of this study is to investigate the differential effects of blue and red light irradiation on ROS scavenging effects. Immortalized human oral keratinocyte HaCat cells were used. Phorbol 12-myristate 13-acetate(PMA) was treated for inflammation. Red(635nm) and blue(470nm) light irradiation was carried out. To asses the intracellular ROS by light irradiation, confocal microscopic and flow cytometric assay with DCF fluorescence for total ROS and ESR spectrometry of DMPO-O2 - for superoxide anion were caried out. And microarray was performed for mRNA expression level. Released intracellular total ROS in PMA treated HaCat cell lines was dissociated efficiently by red light irradiation, while blue light irradiation did not. Rather, blue light irradiation increased ROS formation. For superoxide anion generated the first synthetic form of ROS, red light irradiation reduced its amount but blue light irradiation did not. In the mRNA expression in line with cyclooxygenase(COX) pathway, prostagrandin endoperoxide synthase 1(PTGS 1), prostagrandin endoperoxide synthase 2(PTGS 2) and phospholipase A2(PLA2) were increased by both light irradiation and they were decreased as time flows. And genes associated with ROS releasing, mRNA expressions of tumor necrosis factor receptor (TNFR) and interleukin 1beta(IL1B) were increased by 1 hour red light irradiation but did not by blue light irradiation. As a result, red and blue light irradiation showed different response in affecting the level of ROS. These findings indicate that red light rather than blue light is more useful for anti-inflammation in clinical field

산화는 아스팔트에서 대형분자(LMS : Large Molecular Size) 양의 증가를 야기하고 바인더의 경화에 주요 원인이 되므로 바인더 산화를 저감시키면 도로 및 공항 포장의 공용수명 연장을 기대할 수 있다. 바인더 산화는 혼합물을 도로에 깔기 전에 가열된 골재와 혼합하는 동안과 아스팔트 포장이 시공된 후 공용기간 동안에 일어난다. 본 연구에서는 바인더를 단기 및 장기노화 처리 후 LMS의 양적 증가를 HP-GPC (High-Pressure Gel-Permeation Chromatography)의 자료에 근거하여 해석하였다 개질 아스팔트는 LMS의 증가율이 아스팔트의 종류에 따라 다를 지라도 단기노화 후 LMS의 20-30%증가. 장기노화 후 2배 이상의 증가를 나타냈다. 본 연구에서 개질 아스팔트의 노화특성을 관찰하기 위하여 사용된 개질제는 선행 연구에서 큰 역학적 특성 향상을 보인 LDPE(Low-Density Polyethylene)와 SBS(Styrene-Butadiene-Styrene block copolymers) 를 사용하였다. LDPE로 개질한 바인더는 단 장기노화 후 LMS의 증가 비율이 상당히 낮았다. 이와 같이 낮은 LMS의 증가는 LDPE 개질 아스팔트가 노화 처리되는 동안에 일반 아스팔트보다 덜 노화가 진행된다는 것을 의미한다 이는 아스팔트 시멘트 내에 분산된 LDPE 입자가 산화 노화작용을 방해하기 때문인 것으로 보인다.