• 한국광물학회:학술대회논문집
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• 한국광물학회.한국암석학회 2003년도 공동학술발표회 논문집
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• pp.67-67
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• 2003

The chemical compositions and textural relationships of the Nb-Zr oxide minerals including pyrochlore [ideally (Ca,Na)$_2$Nb$_2$O$\sub$6/(OH,F), with up to 24% UO$_2$ and 16% Ta$_2$O$\sub$5/] and baddeleyite [ideally ZrO$_2$, with up to 6% Nb$_2$O$\sub$5/] in the Sokli carbonatite complex, Kola Peninsula, Arctic are described. These two minerals in carbonatites are the major hosts for the HFSEs such as U, Th, Ta, Nb, Zr and Hf and thus are interest both economically and petrologically. The Sokli carbonatite complex (360-370 Ma) in Northern Finland, which forms a part of the Paleozoic Kola Alkaline Province (KAP), is mainly composed of multi-stages of carbonatite and phoscorite associations (P1-C1 P2-C2, P3-C3, D4 and D5) surrounded by altered ultramafic rocks (olivinite and pyroxenite) and cut by numerous small dikes of ultramafic lamprophyre. The Sokli complex contains the highest concentration in niobium and probably in tantalum, which are economically very important to modern steel technology, among the ultramafic-alkaline complexes of the KAP. Pyrochlore and baddeleyite mostly concentrate in the phoscorites. Pyrochlores in the Sokli complex are generally rounded octahedra and cubes in shape, red brown to grey yellow in color, and 0.2 to 5 mm in size. They are found in all calcite carbonatites, phoscorites and dolomite carbonatites, except P1-C1 rocks. These pyrochlores display remarkable zonations which depend on host rock compositions, and have significant compositional variations with evolution of the Sokli complex. The common variation scheme is that (1) early pyrochlore is highly enriched in U and Ta; (2) these elements decrease abruptly in the intermediate stage, while Th and Ce increase, and (3) late stage pyrochlore is low in U, Ta, Th, and Ce, and correspondingly high in Nb. Baddeleyites in the Sokli complex occur in the early P1-C1 and P2-C2 rocks and rarely in P3. They crystallized earlier than pyrochlores, and occasionally show post-magmatic corrosion and replacement. The FeO and TiO$_2$ contents of baddeleyites are much lower than those of the other terrestrial and lunar baddeleyites, whereas Nb$_2$O$\sub$5/ and Ta$_2$O$\sub$5/ contents are the highest among the reported compositions. Ta/Nb and Zr/Nb ratios of pyrochlores and baddeleyites decrease towards later stage facies, which is in accordance with the whole rock compositions. The variation of Ta/Nb and Zr/Nb ratios of pyrochlores and baddeleyites is considered to be a good indicator to trace an evolution of the carbonatite complexes.

• Journal of Oral Medicine and Pain
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• 제20권1호
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• pp.89-96
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• 1995

The purpose of this study was to assess the pain-relieving effect of iontophoretically applied prednisolone on the patients with temporomandibular joint (TMJ) pain. 30 TMJ pain patients participated in this study. Inclusion criteria for subject selection were 1) tenderness of TMJ on palpation and 2) visual analog scales (VAS) of above 20 mm. The patients with polyarthralgia, rheumatic arthralgia, and systemic diseases were excluded for this experiment. The patients were randomly assigned to one of three groups; (1) Group 1 for administration of 2% prednisolone, (2) Group 2 for administration of 1% prednisolone, and (3) Group 3 for administration of saline. Phoresor PM600(Motion Control Utah, U.S.A) was used for administration of drugs by iontophoresis. Baseline and post-medication pain levels were recorded by VAS, pressure pain threshold (PPT), and palpation index (PI). Post-medication data were compared with baseline data for each group. The results were as follows : 1. All the groups showed significant decrease of VAS scores after treatment. 2. PPT was significantly increase only in Group 1 and 2 not in Group 3. 3. PI was significantly decreased only in Group 1 and 2 not in group 3.

• 대한화학회지
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• 제36권2호
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• pp.218-222
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• 1992

시티딘은 장미조직이 가지고 있는 시티딘 디아미나제에 의해 우리딘과 암모니아 기체를 생성한다. 이 장미조직 50mg을 암모니아 기체감응센서에 고정시켜 장미조직센서를 제조하고, 수용액 중의 시티딘을 정량하는데 최적 실험조건을 조사하였다. pH8.4, 온도 37$^{\circ}C$, 0.2M 인산 완충용액을 사용하였을 때 시티딘의 농도가 $7.0 {\times}10^{-4}$에서 $1.0{\times}10^{-2}$M까지 직선이었고, 53mV/decade의 감응기울기를 나타내었다. 검출한계는 $3.0 {\times} 10^{-4}$ M 상대표준편차는 3.4%였다. 또한 이 조직센서는 선택성이 탁월하였다.

• 한국세라믹학회지
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• 제37권11호
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• pp.1039-1043
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• 2000

$\alpha$-Si$_3$N$_4$가 20vol% 혼합된 SiC/Si$_3$N$_4$혼합물에서 $\alpha$-SiC의 일부를 SiC whisker로 치환하여 첨가한 후 180$0^{\circ}C$, 25MPa의 압력으로 hot pressing하여 SiC/Si$_3$N$_4$/SiCw 복합체를 제조하였다. SiC whisker의 첨가 함량이 증가할수록 상대밀도, 꺽임강도, 마모 저항성은 감소되었으나, 파괴인성은 크게 향상되었다. $\alpha$-SiC의 일부를 SiC whisker로의 치환은 치밀화를 억제하였으나 파괴인성의 증가는 마모 저항성을 향상시키지 않았다.

• 환경생물
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• 제22권3호
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• pp.405-410
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• 2004

The effect of treatment with Citrus junos fractions (citron 3W, citron 3H, citron 4W and citron 4H) upon rat hepatocytes exposed to alcohol was investigated. We compared the serum biochemistry of rats administered both alcohol and Citrus junos fractions to control rats treated with alcohol alone. The effects of Alanine amino transferase (ALT) were significantly lower in the citron 3H extract group compared with the negative control group (p<0.05) and other experimental groups were not significantly low but a little low compared to negative control group. The levels of triglyceride (TG) were significantly low in all experimental groups compared with negative control group. Especially triglyceride level of citron 3H was lowest near to normal control group. The concentration of total cholesterol was significantly high in negative groups compared with normal control group but in all experimental groups, the concentration of total cholesterol was similar to that of negative control group. Total cholesterol of the citron 4W group was somewhat low compared with negative control group. In contrast, activities of alcohol dehydrogenase (ADH) were significantly higher in all experimental groups compared with the negative control (p<0.05) group. These data suggest that Citrus junos fractions may represents an excellent candidate for protection of rat hepatocytes from alcohol-mediated damage.

• 생태와환경
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• 제39권2호통권116호
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• pp.198-208
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• 2006

본 연구는 어류를 이용한 생물학적 수환경 평가기법 즉, '생물통합지수'라 불리는 다변수 모델기법을 적용하는 것이다. 본 연구를 위하여 2004년 8월 ${\sim}$ 2005년 9월까지 갑천에서 5개 지점을 선정하여 조사하였다. 또한 생물학적 자료와 함께 환경부에서 제공되는 장기간의 수진자료와 물리적 서식지 평가 결과를 비교하였다. 어류 군집에 기반으로 한 하천의 생몰학적 건강도 평가를 위하여 Karr(1981)가 제시한 12메트릭 모델을 국내 실정에 맞게 10메트릭 모델로 변형하여 적용하였다. US EPA(1993)와 Karr(1981)의 기준에 따르면 갑천의 평균 생물학적 건강도 지수는 24.0 (범위: 20 ${\sim}$ 30, n=5)으로 보동${\sim}$악화 상태를 나타내었다. 장마기간에 조사된 4차 조사를 제외한 나머지 조사 중 상류부(SI~S3)와 하류부(S4, S5)의 평균 생물학적 건강도 지수는 26.0${\sim}$24.0으로 나타난 반면 4차 조사는 상류부와 하류부가 각각 21.0과 20.0을 기록하였다. 이는 장마로 인한 교란현상을 시사하며 또한 하류부보다는 상류부가 장마의 영향을 심하게 받는 것을 알 수 있다. 물리적 서식지 평가 지수는 75(보통)${\sim}$148(양호)상태를 보였다. 53은 75점을 기록하여 다른 지점에 비하여 상당히 낮은 수치(P=0.001, n=5)를 보였으며 생물학적 건강도 평가 지수 역시 24를 기록하여 상당히 낮은 수치를 보였다. 생물학적 산소요구량, 화학적 산소요구량, 총인, 총질소의 네 항목은 상류에 비하여 하류에서 3${\sim}$8배 가랑 상승하였으며, 이는 생물학적건강도 지수가 이 ${\cdot}$ 화학적 수질과 물리적 서식지를 모두 반영하는 결과라 사료되었다. 이와 같은 이유로 생물학적건강도 평가기법은 하천생태계를 현재를 진단하는 것뿐만이 아니라 나아가서 하천생태계와 수질을 회복하는데 핵심도구로 여겨진다.

• Archives of Pharmacal Research
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• 제15권3호
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• pp.220-223
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• 1992

The methanolic extract of Commelina communis (aerial part) showed antibacterial activity against a cariogenic bacterium, Streptococcus mutans OMZ 176. The active principles were identified to be $\beta$-carboline alkaloids, 1-carbomethoxy-$\beta$-carboline, norharman and harman, which were bactericidal in the minimal inhibitory concentration (MIC) of $100\;\mu{g/ml}$ against the strain.

• International Journal of Air-Conditioning and Refrigeration
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• 제10권3호
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• pp.138-146
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• 2002

The phenomena of energy separation in vortex tubes was investigated experimentally to see the subsidiary effect of the conductivity of tube material and cooling conditions around the outer surface of the tube. The experiment was carried out with pyrex, stainless steel and copper tubes, and the heat transfer conditions of the tubes were with insulation, without in-sulation and water cooling modes respectively The results were obtained that the hot exit fluid temperature was highly affected by a change of conductivity of a tube when the outer surface was cooled by the water, while the working fluid through the tubes was air. How-ever, the cold exit temperature was little affected by the heat transfer modes on the outer surface of the vortex tube.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권11호
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• pp.503-507
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• 2005

Both ratio error and phase angle error in voltage transformer(VT) depend on values of VT burden used. Thus, precise measurement of burden is very important for the evaluation of VT. A method of evaluation for VT burden has been developed by employing the portable decade resistor, with AC-DC resistance difference less than 10-3. The burden value(value and power factor) can be obtained by conductance and susceptance, obtained by measuring the change of ratio error and phase angle error caused by the resistance change of decade resistor. The burden value and power factor obtained by the method are consistent with those obtained using power analyzer within corresponding uncertainties.

• Applied Microscopy
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• 제16권2호
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• pp.35-48
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• 1986

Ultrastructures of the cutaneous xanthophores and formation of pigment granules in the goldfish, Carassius auratus L., are studied with electron microscope. The cutaneous xanthophores are observed only in dermis and pigment granules of these pigment cells are pterinosomes and carotenoid vesicles. By the differentiated level, pterinosomes are subdivided into 3 types; while type I pterinosomes have clear limiting membranes and contain some amorphous fine fibrous structures, type II pterinosomes have thick and densely aggregated fibrous materials. Type III pterinosomes have concentric lamellar structures in the granules. Pigment granules of the xanthophores are originated from the Golgi complexes and pinocytotic vesicles of plasma membrane as well as rER-rich cells among the chromatophores are presumed to be associated with the accumulation of pigment materials.