• Economic and Environmental Geology
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• v.34 no.1
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• pp.1-12
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• 2001

The crystal structure of biotite-1M from Bancroft, Ontario, was determined by Rietveld refinement method using high-resolution neutron powder diffraction data at -26.3$^{\circ}C$, 2$0^{\circ}C$, 30$0^{\circ}C$, $600^{\circ}C$, 90$0^{\circ}C$. The crystal structure has been refined to a R sub(B) of 5.06%-11.9% and S (Goodness of fitness) of 2.97-3.94. The expansion rate of a, b, c unit cell dimensions with elevated temperature linearly increase to $600^{\circ}C$. The expansivity of the c dimension is $1.61{\times}10^{40}C^{-1}$, while $2.73{\times}10^{50}C^{-1}$ and $5.71{\times}10^{-50}C^{-1}$ for the a and b dimensions, respectively. Thus, the volume increase of the unit cell is dominated by expansion of the c axis as increasing temperature. In contrast to the trend, the expansivity of the dimensions is decreased at 90$0^{\circ}C$. It may be attributed to a change in cation size caused by dehydroxylation-oxidation of $Fe^{2+}$ to $Fe^{3+}$ in vacuum condition at such high temperature. The position of H-proton was determined by the refinement of diffraction pattern at low temperature (-2.63$^{\circ}C$). The position is 0.9103${\AA}$ from the O sub(4) location and located at atomic coordinates (x/a=0.138, y/b=0.5, z/c=0.305) with the OH vector almost normal to plane (001). According to the increase of the temperature, $\alpha$* (tetrahedral rotation angle), $t_{oct}$ (octahedral sheet thickness), mean distance increase except 90$0^{\circ}C$ data. But the trend is less clearly relative to unit cell dimension expansion because the expansion is dominant to the interlayer. Also, ${\Psi}$ (octahedral flattening angle) shows no trends as increasing temperature and it may be because the octahedron (M1, M2) is substituted by Mg and Fe.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.1
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• pp.18-22
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• 2002

This experiment was conducted to investigate the effect of night illumination on the growth and yield of wheat and barley. Three varieties of barley and four cultivars of wheat were tested under the different night illuminance which was controlled in the range of 1.2∼20 Lux during whole growth season at night. As night illumination was stronger, the culm length of all varieties tended to be shorter. The shortening was greater in barley than wheat. Node number, awn length and culm diameter tended to decrease as the light intensity was stronger. Internode length above the 4th and 5th node was remarkably decreased by the stronger illuminance. The degree of decrease in spike length affected by the night illuminance was much larger in the late-maturing variety among wheat cultivars. As night illumination was stronger, days to heading was shortened in general. The range of decrease was 2 to 10 days under 10∼20 Lux condition similarly in both barley and wheat. Effect of night illumination on heading date and days from initial heading to full heading was not considerably different between the crops and among varieties except Kangbori. Night illumination decreased the grain yield by 12.5% in barley, and 11.0% in wheat at 2.1∼5.0 Lux condition, and 34.6% in barley, and 29.3 % in wheat at 10∼20 Lux condition compared to control. Yield reduction was significantly different among varieties, being greatest in Kangbori among barley varieties, and in Chokwang (late-maturring variety) and Changkwang (late-maturring variety) among wheat varieties. It was interpreted that the decrease of grain yield was resulted from the decrease in the number of spikes and the number of grains per spike under the stronger night illumination. The decrease of grain yield was more directly attributed to the decrease in the number of grains per spike.

• Food Industry
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• s.181
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• pp.10-37
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• 2004

식용유지는 식용으로 이용할 수 있는 가시적인 상태의 액상(oil) 또는 고체상(fat)의 식용기름을 말하지만 식품산업 측면에서는 가시적인 상태의 유지(가시지방)뿐만 아니라 유지가공 식품이나 기타의 식품에 함유되어 섭취되는 비가시적인 상태의 유지(비가지 지방)도 포함될 수 있다. 식용유지는 생명을 유지하는데 없어서는 안될 영양소로서 탄수화물 단백질과 함께 3대 영양소 중의 하나이며 1g당 9kcal를 내는 고도로 농축된 에너지원이면서 필수지방산의 공급원이고 비타민 A, D, E 등의 지용성 비타민과 기타 특수한 영양성분의 운반체로서 높은 영양적 가치를 갖는다. 지방성분은 음식물로부터 섭취가 불가능할 경우에는 체내에서 탄수화물이나 단백질을 기질로 하는 대사과정에서 합성되어 지질 또는 필수지방산과 지용성 비타민은 식품으로 지방질과 함께 흡수되어야 하므로 식품의 한 성분으로 지방의 중요성을 인정받고 있다. 1960년대 이후 국민소득의 증가와 함께 식생활도 다양화되고 서구화 간편화되면서 지방 함량이 높은 식품과 유지를 이용한 식품의 소비가 증가하였고 전체적인 유지 소비량도 늘어나는 추세에 있다. 60년대 초에는 총열량 중 지방이 차지하는 비율이 $6\%$ 정도였으나 최근에는 급격히 증가되어 2000년말 현재 $25.5\%$로 증가하였다. 97년까지 계속 증가하던 공급 에너지량은 98년 IMF의 영향으로 2,799 kcal까지 감소했으나 99년 들어 IMF 이전 수준으로 회복되었다. 또한 연간 일인당 순 식용유지류 공급량은 1990년대 까지 급격히 증가하였으나 이후로는 소폭 증가하는 추세이다. 2000년말 현재 식용유지 총 공급량은 76만2 천톤으로써 99년 73만5 천톤에 비해 2.7만톤이 증가하였다. 1998년 IMF 시기를 제외하고는 공급물량은 계속해서 증가 추세이다. 특히 1998년도에 비하여 2000년도에 식물성 유지는 2배 가까이 증가하였으나, 동물성 유지는 절반 이하로 감소되는 추세이며 공급물량으로 보면 대두유, 팜유가 주요 유종으로 식물유지 전체에서 차지하는 비중이 $72.3\%$로 압도적이다. 라면용 튀김기름과 마가린 쇼트닝의 원료로서 대부분 사용되는 팜유를 제외하고 가정용 식용유의 대부분을 차지하는 대두유가 이처럼 식용유지 시장의 대부분을 차지하게 된 이유는 첫째, 90년대 초반 수입 자유화 이후 타 유종 대비 낮은 가격을 형성하여 유지업체가 수입을 늘린 것이고 둘째로는 국내에서 대두유와 대두박을 생산하는 대두가공업체의 안정적 대두유 공급이 주요 원인이라고 할 수 있다. 식용유지의 시장규모는 식품공전상 식용유지로 분류된 제품들의 2000년도 출하액으로 보면 약 6,616 억원 정도이다. 한편 유종이 단순했던 가정용 식용유지 시장이 최근 새로워지고 있다. 주로 조리용으로 사용했던 것에서 건강을 생각하는 품목으로 바뀌는 경향이다. 아직은 가정용에서 대두유가 가장 많지만 옥배유나 채종유 더 나아가 건강이미지의 식용유인 홍화유 올리브유 해바라기유등이 증가하고 있는 추세이다. 한편 기존 식용유가 비만의 원인인 것 때문에 기피되던 것에서 새롭게 다이어트용 식용유 제품이 출시되어 시장에 새 바람이 불고 있다. 일본 식용유지 시장규모는 물량으로 172 만톤, 금액으로는 2,786 억엔(약 2조7860 억원) 수준이다. 지난 10년간 증가율은 물량 측면에서 약 $5\%$정도 신장하고 금액으로는 큰 증감이 없었다. 식용유는 조리의 기초 소재로서 안정한 수요를 갖고 있지만 주요 유종인 샐러드유의 가격이 하락하여, 전체적으로 시장이 물량이 증가하면서도 매출액이 신장하지 못하여 시장규모는 축소되었다고 할 수 있다. 일본 식용유지 업계의 제품동향을 보면 거의 모든 업체가 가정용 시장에서 건강 기능성 식용유지를 출시하고 있다는 점이다. 물론 일본은 건강기능성 식품에 대한 제도적인 뒷 받침이 되어 있어 기능성 식품의 시장출시가 용이한 점이 가정용 시장에 큰 영향을 미쳤다고 볼 수 있다. 유지 산업의 고부가가치화를 위해서는 전통적인 산업의 제품과 기술만으로는 달성하기 어렵다. 국내와 일본 식용유지 업계의 경향을 참고해 볼 때 차별화된 식용유지 제품과 기술의 개발이 절실히 필요하다. 앞서 언급한 고부가가치 제품과 기술 관련 사향을 바탕으로 국내 유지분야가 중점적으로 연구할 분야를 선정해 보면 리파제의 고정화 연구, 생물공학 기술을 활용한 효소의 개발과 이를 이용한 유지 가공 기술 연구, 유지성분의 유화 안정화 기술 연구, 식용유지의 선택적 수소경화 기술 연구 트랜스 지방산 저감기술연구, 효소 반응조 설계기술 연구, 지질 분자구조 분석기술 연구 분야 등이 유망하다. 상기와 같은 연구 분야를 육성하기 위해서는 유지 전문 인력의 육성, 해외 네트웍의 구축, 산학연 공동연구 추진, 국가적 차원의 정책 및 지원 등이 절실하다.

• Korean Journal of Food Science and Technology
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• v.51 no.4
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• pp.379-392
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• 2019

The current study investigated the effect of Gabjubaekmok (Diospyros kaki) ethanolic extract (GEE) on $H_2O_2$-induced human neuroblastoma MC-IXC cells and amyloid beta $(A{\beta})_{1-42}$-induced ICR (Institute of Cancer Research) mice. GEE showed significant antioxidant activity that was evaluated based on ABTS, DPPH scavenging activity, and inhibition of malondialdehyde (MDA) and acetylcholinesterase activity. Further, GEE inhibited ROS production and increased cell viability in $H_2O_2$-induced MC-IXC cells. Administration of GEE ameliorated the cognitive dysfunction on $A{\beta}$-induced ICR mice as evaluated using Y-maze, passive avoidance, and Morris water maze tests. Results of ex vivo test using brain tissues showed that, GEE protected the cholinergic system and mitochondrial functions by increasing the levels of antioxidants such as ROS, mitochondrial membrane potential (MMP), and adenosine triphosphate (ATP) against $A{\beta}$-induced cognitive dysfunction. Moreover, GEE decreasd the expression levels of apoptosis-related proteins such as $TNF-{\alpha}$, p-JNK, p-tau, BAX and caspase 3. While, expression levels of p-Akt and $p-GSK3{\beta}$ increased than $A{\beta}$ group. Finally, gallic acid was identified as the main compound of GEE using high performance liquid chromatography.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.207-213
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• 1998

On the basis of the previous study[1], miscibility were investigated and intermolecular interaction strength for the miscibility were relatively compared for the blends poly{2,2-(m-phenylene)-5,5'-bibenzimidazole}(PBI) with two aromatic polyimides (PIs) synthesized by another dianhydride. Aromatic PAAs were prepared by the reaction of condensation of two diamines, 4,4'-methylene dianiline(4,4'-MDA) and 4,4'-oxydianiline(4,4'-ODA) with 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride(DSDA) using DMAc, and then converted into PIs after curing. PBI/PAA blends were prepared by solution blending. Cast films or precipitated powders of the PBI/PAA blends were cared at a high temperature to transform into PBI/PIs blends. Miscibility and specific intermolecular interaction for miscibility in the blends were investigated, and compared with previous polyimide structures of PBI/PIs blends [1]. Two blends, PBI/DSDA+4,4'-MDA(Blend-V) and PBI/DSDA+4,4'-ODA(Blend-VI), were found miscible : the evidences were optically clear films, synergistic single composition dependent $T_g{\prime}s$, and frequency shifts of N-H stretching band as much as $39{\sim}40cm^{-1}$, and of C=O stretching band near 1730 and $1780cm^{-1}$, 5~6 and $3{\sim}4cm^{-1}$, respectively. The specific intermolecular interactions existing between PBI and PIs were relatively analyzed with the area(A) formed between the $T_g{\prime}s$ of the measured and that of the calculated by the Fox equation at all compositions, the ${\kappa}$ values in Gordon-Taylor equation obtained from the measured $T_g{\prime}s$, and differences of the frequency shifts in the functional N-H and carbonyl stretching band. From the results, the area(A) and the ${\kappa}$ values for Blend-V and VI were smaller than those for Blend-III and IV used in previous study[1]. Differences of the frequency shifts in the functional groups(N-H and C=O) also showed similar tendency. Thus, specific intermolecular interaction strength in terms of hydrogen bonding of PBI/PI blends is dependent upon chemical structures of PIs, that is, PIs it seems that $SO_2$ group in dianhydride(DSDA) has weaker hydrogen bond strength than those of C=O in BTDA. In other words, it implies that the former occupied bulk space than the latter due to the sterric effect.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.517-535
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• 2007

Two distinctive Mesozoic hydrothermal systems occurred in South Korea: the Jurassic/Early Cretaceous(ca. $200{\sim}130$ Ma) deep-level ones during the Daebo orogeny and the Late Cretaceous/Tertiary(ca. $110{\sim}45$ Ma) shallow hydrothermal ones during the Bulgugsa event. The Mesozoic hydrothermal system and the metallic mineralization in the Korean Peninsula document a close spatial and temporal relationship with syn- to post-tectonic magmatism. The calculated ${\delta}^{18}O_{H2O}$ values of the ore-forming fluids from the Mesozoic metallic mineral deposits show limited range for the Jurassic ones but variable range for the Late Cretaceous ones. The orogenic mineral deposits were formed at relatively high temperatures and deep-crustal levels. The mineralizing fluids that were responsible for the formation of theses deposits are characterized by the reasonably homogeneous and similar ranges of ${\delta}^{18}O_{H2O}$ values. This implies that the ore-forming fluids were principally derived from spatially associated Jurassic granitoids and related pegmatite. On the contrary, the Late Cretaceous ferroalloy, base-metal and precious-metal deposits in the Taebaeksan, Okcheon and Gyeongsang basins occurred as vein, replacement, breccia-pipe, porphyry-style and skarn deposits. Diverse mineralization styles represent a spatial and temporal distinction between the proximal environment of subvolcanic activity and the distal to transitional condition derived from volcanic environments. The Cu(-Au) or Fe-Mo-W deposits are proximal to a magmatic source, whereas the polymetallic or the precious-metal deposits are more distal to transitional. On the basis of the overall ${\delta}^{18}O_{H2O}$ values of various ore deposits in these areas, it can be briefed that the ore fluids show very extensive oxygen isotope exchange with country rocks, though the ${\delta}D_{H2O}$ values are relatively homogeneous and similarly restricted.

• Journal of the Korean Electrochemical Society
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• v.10 no.4
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• pp.283-287
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• 2007

KIER has been developing the anode-supported flat tubular solid oxide fuel cell unit bundle for the intermediate temperature($700{\sim}800^{\circ}C$) operation. Anode-supported flat tubular cells have Ni/YSZ cermet anode support, 8 moi.% $Y_2O_3$ stabilized $ZrO_2(YSZ)$ thin electrolyte, and cathode multi-layer composed of Sr-doped $LaSrMnO_3(LSM)$, LSM-YSZ composite, and $LaSrCoFeO_3(LSCF)$. The prepared anode-supported flat tubular cell was joined with ferritic stainless steel cap by induction brazing process. Current collection for the cathode was achieved by winding Ag wire and $La_{0.6}Sr_{0.4}CoO_3(LSCo)$ paste, while current collection for the anode was achieved by using Ni wire and felt. For making stack, the prepared anode-supported flat tubular cells with effective electrode area of $90\;cm^2$ connected in series with 12 unit bundles, in which unit bundle consists of two cells connected in parallel. The performance of unit bundle in 3% humidified $H_2$ and air at $800^{\circ}C$ shows maximum power density of $0.39\;W/cm^2$ (@ 0.7V). Through these experiments, we obtained basic technology of the anode-supported flat tubular cell and established the proprietary concept of the anode-supported flat tubular cell unit bundle.