A ZIF-8 membrane was prepared via counter diffusion method. To control the diffusion rate, two supports with different pore structure were employed, conventional and modified α-Al2O3 disc; disc A and disc B. The ZIF-8 membranes are derived their name from the supports; ZIF-8-A and ZIF-8-B. While ZIF-8-A was grown at the surface of the disc A, ZIF-8-B was grown inside the disc B. At 200°C, ZIF-8-A and -B exhibited H2/CO2 separation factor (SF) of 6.69 and 8.21. In long-term thermal stability tests, both ZIF-8-A and -B were withstood their properties at 200 and 250°C for 72 h. At 300°C, SF of ZIF-8-A fell after ~2 h, however, that of ZIF-8-B dropped after ~10 h. To sum up these features, ZIF-8-B showed higher H2 selectivity and thermal stability than ZIF-8-A, since ZIF-8 membrane was synthesized inside of the support.

The principal consisting rocks of study area are Precambrian metasedimentary bedrocks, Cambro-ordovician sedimentary rocks and Samhwa granite which have intruded these metasedimentary and sedimentary rocks. The reddish K-feldspar bearing Samhwa granite presettts miarolitic texture and graphic intergrowth between quartz and K-feldspar. The granite, homogeneous in chemical composition of major elements, belongs to Calc-alkali rocks of subalkali series. According to AMF diagram, the granite was crystallized at the latest stage of the differentiation of magma. The Samhwa granite belongs to I-type granitoids and magnetite-series granitoids. Especially, this granite is thought to be crystallized in the epicrust with high oxygen fugacity. The Samhwa granite has similar characteristics to masanite of cretaceous granitic rocks of Gyeongsang basin in the petrological and petrochemical properties. The biotite age of the granite by K-Ar age dating is 50.1±1.5. Finally, contact metamorphic zone of limestone by granite intrusion contains distinct minerals such as diopside, brucite, tremolite and muscovite, which indicate low temperature metamorphic grade.

The general aspects of the selection of science subjects for the enterance examination of college and the factors affecting on tendency of the selection were investigated by using the data of registration records from a preparatory school for examinees. Major findings of this study are as follows. Firstly, most of the students choose biology and the rest of them chemistry, earth science and physics in order. Secondly, the difference of the tendency of selection of subjects for male and female students are not found. Thirdly, the correlation between the score of the national preliminary enterance examination for college and that of the trial examination in preparatory school is neglibibly small.

The papers of earth science examinations given during the first semester of 1981 academic year were collected from the seventy five high schools randomly chosen all over the country. The examination questions were analyzed and evaluated in order to grasp the current state and issues of earth science education. Some critical remarks and suggestions are made for improvement of the earth science education at the secondary school level.

Background: Camellia sinensis L.(CS) is a perennial evergreen species of plant whose leaves are used to produce tea. In this plant species, the parts used are the leaves, sub-branch parts are thrown out. Methods and Results: Ethanol extract of sub-branch parts was used for isolation of major compounds by column chromatography. Structures were identified as caffeine (1), (-)-epicatechin (2) and (-)-epicatechin gallate (3) by interpretation of spectroscopic analysis, including 1H- and 13C-NMR. High-performance liquid chromatography (HPLC) method was used to compare the quantitative level of marker compounds in various extraction solvents of sub-branch parts of CS. The content of caffeine, (-)-epicatechin, and (-)- epicatechin gallate in 30% ethanol extract showed higher value with 3.28 ± 0.57 ㎎/g, 5.53 ± 0.88 ㎎/g, and 1.29 ± 0.24 ㎎/g, respectively. Conclusions: These results indicated that not only leaves parts but also sub-branch, could be a good source for the functional material and pharmaceutical industry.

In this study, the anti-inflammatory activities of the extracts of different parts of Hovenia dulcis such as leaves, stems, and roots were investigated. Among them, the roots extract (RE) showed the most potent suppressive effect against pro-inflammatory mediators in LPS-stimulated mouse macrophage cells. RE induced dose-dependent reduction of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and concomitantly reduced the production of NO and PGE2. Additionally, pre-treatment with RE significantly suppressed the production of inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6, as well as mRNA levels. Moreover, phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear translocation of nuclear factor-kappa B (NF-kB) were also strongly attenuated by RE in RAW264.7 cell. Furthermore, RE induced HO-1 expression through nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) and increase HO-1 activity in RAW264.7 macrophages. Therefore, these results indicate that RE strongly inhibits LPS-induced inflammatory responses by blocking NF-kB activation, inhibiting MAPKs phosphorylation, and enhancing HO-1 expression in macrophages, suggesting that RE of H. dulicis and a major component, 27-O-protocatechuoylbetulinic acid could be applied as a valuable natural anti-inflammatory material.