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최상준,손종락,류삼곤 한국화학공학회 1989 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.27 No.2
Y형 제올라이트를 높은 온도에서 SiCl₄, 수증기 및 EDTA로 처리하여 일련의 탈알미늄화된 제올라이트를 만들었다. SiCl₄로 탈알미늄화된 제올라이트는 수증기나 EDTA로 탈알미늄화된 것에 비하여 결정의 파괴없이 완전하였다. 그리고 탈알미늄화 제법에 관계없이 0-(Si, Al)-0 신축진동에 의한 적외선 흡수 밴드는 단위 세포당의 골격구조의 Al 원자수가 감소함에 따라 높은 파수쪽으로 이동하였다. 높은 파수(3640㎝^(-1))에 있는 수산기 밴드는 골격구조의 Si/Al비가 약5까지는 Si/Al비가 증가함에 따라 거의 선형적으로 저파수쪽으로 이동하였으나 Si/Al비가 5이상에는 변하지 아니하였다. 탈알미늄화됨에 따라 제올라이트의 net 정전기적 하전의 감소 때문에 수분을 흡수하는 능력이 감소하였다. A series of dealuminated Y-type zeolites was prepared by treating zeolites with SiCl₄, steam, and EDTA at elevated temperatures. Y-type zeolites can be dealuminated by reaction with SiCl₄ without collapse of the crystal structure as compared with the treatment of steam and EDTA. Regardless of preparation method, the infrared absorption bands in frequency of the stretching O-(Si, Al)-O vibrations shifted in a linear manner as number of framework Al atoms per unit cell. The high-frequency hydrouy band (3640 ㎝^(-1)) decreased in wavenumber almost linearly with an increasing Si/Al ratio of the zeolite, but beyond a ratio close to 5, the frequency remained virtually unchanged. Upon dealumination the ability of the zeolite to absorb water decreased due to the decrease of net electrostatic charge.
최상준 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.9
Results of the comparisons of various density functional theory (DFT) methods with different basis sets for predicting the molecular geometry of TPOP24N-Oxide macrocycle, an oxoporphyrin N-oxide, are reported in this paper. DFT methods, including M06-2X, B3LYP, LSDA, B3PW91, PBEPBE, and BPV86, are examined. Different basis sets, such as 6-31G*, 6-31+G (d, p), 6-311+G (d, p), and 6-311++G (d, p), are also considered. The M06-2X/6-31G* level is superior to all other density functional methods used in predicting the geometry of TPOP24N-Oxide. The geometries of regioisomeric chlorin N-oxide and oxoporphyrin N-oxide are reported using M06-2X/6-31G* method. The geometry effects of oxoporphyrin and chlorin N-oxide regioisomers are increased β-β bond lengths by N-oxidation because the bond overlap index due to charge transfers is decreased. In N-oxidation ring (II, III), angles that include β-β bond length increase as the bond overlap index of β-β bond is decreased by N-oxidation. The potential energy surfaces of chlorin N-oxide and oxoporphyrin N-oxide are explored by M06-2X/6-31G*, and single-point calculations are performed at levels up to M06-2X/6-311++G (d, p). Total and relative energies are then calculated. The results indicate that chlorin 24 N-oxides are more stable than chlorin 22 N-oxides in chlorin N-oxide regioisomers. Moreover, TPOP24N-Oxide is less stable than TPOP22N-Oxide.
대기오염과 실내 거주자의 활동도가 교실 내부의 입자 크기별 먼지 농도에 미치는 영향
최상준,Choi, Sang-Jun 한국환경보건학회 2008 한국환경보건학회지 Vol.34 No.2
This study evaluated the effects of the human activity and outdoor air on concentrations of size-selective particulate matters (PM) by conducting a realtime measurement in classrooms and on roofs at 4 elementary schools, 3 middle schools and 3 high schools in Incheon City. PM concentrations featured repetitive pattern of increasing during break time (including lunch hours) and cleaning time while decreasing during class hours. This trend was more prominent with inhalable PM and PM10 than fine PMs (PM2.5, PM1.0). The indoor/outdoor (I/O) ratio of inhalable PM and PM10 exceeded 1 while that of fine PMs was close to or below 1. The PM2.5 (out)/PM10 (out) ratio stood at 0.59 (${\pm}0.16$) and the PM2.5 (in)/PM10 (in) ratio was 0.29 (${\pm}0.09$), suggesting that occupant activity had a greater effect upon coarse particles (PM10-PM2.5) than upon fine particles (PM2.5, PM1.0). The correlations between the indoor and the outdoor PM concentrations showed a stronger positive correlation for fine particles than that of coarse particles. The linear regression analysis of PM concentrations indoor and outdoor indicated a higher determinant coefficient ($r^2>0.9$), and consistency for fine particles than in case of coarse particles. In conclusion, the results of this study suggest that the indoor coarse particle concentration is more attributed to occupant activity and the indoor fine particle concentration is more influenced by outdoor air pollution.