Recently, concern about Sick House Syndrome (SHS) has been increased in Korea. And it is suspected that formaldehyde (HCHO) and volatile organic compounds (VOCs) are major factors for SHS. This study was surveyed the indoor air quality in new apartments in Korea. The HCHO and VOCs were measured at 90 sites and analysed by HPLC-UV and GC/MS, respectively. The range of HCHO concentrations at 90 sites were 9.39∼248.78㎍/㎥ and the mean value 105.41㎍/㎥ and the concentrations of HCHO at 42 sites (46.7%) exceeded the indoor air quality guideline (100㎍/㎥) in Japan. Among the 4 VOCs, toluene concentrations were the highest and the mean value 127.33㎍/㎥ and that concentrations at 12 sites (13.8%) were exceeded the indoor air quality guideline (260㎍/㎥) in Japan. There was a tendency which the longer the movement and measurement period is, the more the pollutants concentration is decreased. HCHO and VOCs concentrations of domestic results was similar to Japan's survey results in 2000.
Submicron nickel powders were prepared from aqueous solution under hydrothermal condition. The experimental conditions including the types of protective agents, concentration of the solution and the pH were studied in detail. Starting concentration of nickel ion is a dominant factor affecting particle size. It was shown that the subsequent addition of Poly Vinyl Pyrrolidone(PVP) and Sodium Dodecyle Sulfate(SDS) can help to disperse the nickel powder. X-ray diffraction and SEM were employed to characterize the products.
노상 및 보조기층 등 포장하부기초의 강성도 평가를 위해 공내재하시험이 효과적으로 사용될 수 있다. 현재 국내에서 포장하부기초 강성도의 평가를 위해 사용되는 가장 실용적인 방법은 평판재하시험 (PBT)과 CBR 시험을 들 수 있다. 그러나 이 방법들은 시험법 자체가 안고있는 불합리성과 결과치의 변화가 크다는 단점으로 인해 결과의 신뢰도가 떨어진다. 주 연구에서는 공내재하시험기를 사용한 포장하부기초 강성도의 평가방법과 시험절차의 개발 가능성을 검토하였다. 개발된 시험법의 평가를 위해 현장 평판재하시험 결과와 비교하였으며 이로부터 공내재하시험 재재하 탄성계수(ER)와 평판재하시험 (PBT) 수직지반 반력계수 k와의 유효한 상관도를 설정할 수 있었다.