• 한국수산과학회지
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• 제32권4호
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• pp.470-475
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• 1999

본 연구는 무지개송어 사료의 어분 대체사료원으로서 육골분(MBM), 우모분(FM), 오징어내장분 (SLP), 가금부산물 (PBP) 및 혈분 (BM)을 특정비율로 혼합하여 제조한 어분대체품(ABPM)을 제작하여 사료내 어분의 대체가능성을 조사하고 사료내 소화율 측정에 이용하는 지표물질인 $Cr_2O_3$ 첨가가 성장에 미치는 영향에 관한 자료를 얻고자 실시하였다. 본 실험사료의 주단백질원으로는 동물성단백 질원으로 북양어분 (White fish meal, WFM)과 축산가공부 산혼합물 (ABPM)을 식물성으로 대두박과 콘글루텐밀을 사용하였다. 사료 1과 사료 2의 사료는 National Research Council(NRC, 1993)자료에 근거하여 조단백질 함량은 $46.5\%$, 가용성 에너지는 16.7 KJ/g (protein, carbohydrate and lipid: 16.7, 16.7 and 37.7 KJ/g)으로 동일하게 맞추어 주었다. 실험사료는 사료 1 (WFM 100), 사료2(ABPM 40), 사료3(상업사료(-Cr)), 사료 4(상업사료+$0.5\%$ $Cr_2O_3$(+Cr))로 4가지를 사용하였다. 일주일간의 예비사육 후 평균무게 2.1g$\pm$0.2인 치어를 30마리씩 3반복으로 무작위 배치하여 4주간 사육한후, 성장속도가 비슷한 평균무게 6.8$\pm$0.3g의 어류를 동일한 사료군내에서 선택하여 20마리씩 2 반복 재배치하여 4주간 사육하였다. 8 주간 사료 공급후 사료 2는 다른 모든 사료구에 비해 증체율 (WG, $\%$)과 사료효율 (FE, $\%$)이 유의적으로 낮았다 (P<0.05). 어체의 혈액분석결과 헤마토크리트t는 전사료구간에 유의차가 없었다 (P>0.05). 전어체 일반성분 분석 결과 수분 및 조단백질 함량은 모든 사료구간에 유의적 차이가 없었으나 (P>0.05), 사료 1의 조지방 함량은 다른 사료구에 비해 유의적으로 높았다 (P<0.05). 어체의 비만도는 사료 2가 다른 사료구에 비해 유의적으로 높았다 (P<0.05). 혈액, 뼈 및 전어체의 인 함량 및 뼈의 회분 함량은 모든 사료구간에 유의적인 차이가 없었다 (P>0.05). 상업사료내 산화크롬을 첨가하거나 혹은 첨가하지 않고 8주간 사육한 결과 산화크롬 $0.5\%$의 8주간 첨가는 성장에 영향을 주지 않았을 뿐 아니라 전어체의 일반성분, 혈장 및 뼈 조직 중의 인과 회분 함량에도 영향을 주지 않았다. 본 실험 결과, 무지개 송어 사료내 어분단백질 대체원으로 본축산가공부산혼합물의 이용은 $40\%$ 수준 이하에서 가능하다고 판단되고 산화크롬은 성장 및 전어체의 일반성분에 영향을 주지 않았으므로 사료내 영양소의 소화율 측정에 $0.5\%$ 의 산화크롬 첨가는 별다른 문제가 없음을 보여주었다.

• 자원환경지질
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• 제31권2호
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• pp.111-125
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• 1998

Dispersion, migration and enrichment of environmental toxic elements from the Samkwang Au-Ag mine area were investigated based upon major, minor and rare earth element geochemistry. The Samkwang mine area composed mainly of Precambrian granitic gneiss. The mine had been mined for gold and silver, but closed in 1996. According to the X-ray powder diffraction, mineral composition of stream sediments and soils were partly variable mineralogy, which are composed of quartz, orthoclase, plagioclase, amphibole, muscovite, biotite and chlorite, respectively. Major element variations of the host granitic gneiss, stream sediments and soils of mining and non-mining drainage, indicate that those compositions are decrese $Al_2O_3$, $Fe_2O_3$, MgO, $TiO_2$, $P_2O_5$ and LOI with increasing $SiO_2$ respectively. Average compositional ranges (ppm) of minor and/or environmental toxic elements within those samples are revealed as As=<2-4500, Cd=<1-24, Cu=6-117, Sb=1-29, Pb=17-1377 and Zn=32-938, which are extremely high concentrations of sediments from the mining drainage (As=2006, Cd=l1, Cu=71, Pb=587 and Zn=481 ppm, respectively) than concentrations of the other samples and host granitic gneiss. Major elements (average enrichment index=6.53) in all samples are mostly enriched, excepting $SiO_2$, $Na_2O$ and $K_2O$, normalized by composition of host granitic gneiss. Rare earth element (average enrichment index=2.34) are enriched with the sediments from the mining drainage. Minor and/or environmental toxic elements within all samples on the basis of host rock were strongly enriched of all elements (especially As, Br, Cu, Pb and Zn), excepting Ba, Cr, Rb and Sr. Average enrichment index of trace elements in all samples is 15.55 (sediments of mining drainage=37.33). Potentially toxic elements (As, Cd, Cr, Cu, Ni, Pb, and Zn) of the samples revealed that average enrichment index is 46.10 (sediments of mining drainage=80.20, sediments of nonmining drainage=5.35, sediments of confluent drainage=20.22, subsurface soils of mining drainage=7.97 and subsurface soils of non-mining drainage=4.15). Sediments and soils of highly concentrated toxic elements are contained some pyrite, arsenopyrite, sphalerite, galena and goethite.

• 한국자기학회지
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• 제17권2호
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• pp.86-89
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• 2007

고압으로 제조된 $FeCr_2Se_4$의 전기 및 자기적 특성을 연구하기 위해 XRD, SQUID, 중성자회절, 비저항 측정 및 Mossbauer 분광실험을 수행하였다. 비저항 측정결과 온도전반에 걸쳐 반도체적 거동을 보였으며, 온도가 증가함에 따라 저항이 급격하게 감소하는 구간 I(T<20 K)와 온도가 증가함에 따라 저항이 천천히 감소하는 구간 II(T>42 K)으로 2의 구간으로 구분하여 각 각 Mott-VRH(variable range hopping)모델, small polaron 모델을 이용하여 갭 에너지를 계산하였다. 중성자회절실험 분석치를 비교한 결과 110K 이하에서 ferromagnetic 결합이 크게 작용하며, 110 K이상 Neel 온도 이하에서는 격자상수의 급격한 증가론 관찰할 수 있었다. $M\"{o}ssbauer$ 분광실험 결과, 자기 이중극자 상호작용에 대한 전기 사중극자 상호작용의 비 R값이 온도 상승과 더불어 증가하다가 55 K 부근에서 최대치를 형성한 후 Neel 온도로 접근함에 따라 급격히 감소한다.

• 대한안전경영과학회지
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• 제2권4호
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• pp.177-186
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• 2000

The molten carbonate fuel cell has conspicuous features and high potential in being used as an energy converter of various fuels to electricity and heat. However, the MCFC which use strongly corrosive molten carbonate at $650^{\circ}C$ have many problem. Systematic investigation on corrosion behavior of Fe/20Cr/Ti has been done in (62+38)mol % (Li+K) $CO_3$ melt at 923K by using. steady state polarization and electrochemical impedance spectroscopy method. It found that the corrosion current of these Febased alloys decreased with increasing Ti content, and this attribute to the formation of $LiCrO_2$ layer at the surface.

• 한국광물학회지
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• 제21권2호
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• pp.177-182
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• 2008

캐나다 브리티시 콜럼비아주 카시아르광산에서 산출되는 B.C. jade에 대한 보석학적 특징을 알아보기 위하여 편광현미경 관찰, 경도, 굴절율 및 비중 측정, X-선회절분석, X-선형광분석, ICP-MS, 적외선흡수분광분석, 시차열분석/열중량분석 등을 실시하였다. B.C. jade는 짙은 녹색을 띠고 반투명하며, 지방광택을 나타내며, 주구성광물은 투각섬석-양기석 고용체이다. 미량의 석류석과 미화인된 불투명광물이 공생한다. 모스 경도는 $5.5{\sim}6$, 굴절율은 1.62, 비중 3.01이다. 인성이 강하며 침상단구를 나나낸다. Fe의 함량이 높으며($Fe_2O_3\;4.14{\sim}4.66\;wt%$) 녹색을 띠게 하는 발색소 역할을 하는 것으로 해석된다. B.C. jade는 $926.9^{\circ}C$에서 탈수현상이 일어나면서 파괴되기 시작하며, $1000.8^{\circ}C$에서 투각섬석-양기석이 투휘석+엔스타타이트+석영+물($H_2O$)로 분해되는 반응이 거의 완결되는 것으로 해석된다. 이러한 가능성은 $926.9^{\circ}C$ 이상에서 1.93 wt%의 중량손실이 일어나는 열중량 분석결과와 잘 일치한다.

• 한국물환경학회지
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• 제26권5호
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• pp.725-731
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• 2010

This study was to evaluate the ozone oxidation of dissolved Fe, Mn, $SO{_4}^{2-}$ ions and color in abandoned mining drainage by conducting a bench-scale operation at various reaction times in an ozone reactor. The influent was collected from an abandoned mine drainage (AMD) near the J Mine in Jungsungun, Kangwon Province. The ozone reactor was operated at ozone reaction times of 10, 20 and 30 min with ozone doses of 0.0 and $2.4g\;O_3/hr$. Samples from each effluent from subsequent sand filtration were regularly collected and analyzed for pH, Fe, Mn, Al, Cr, Hg, $SO{_4}^{2-}$, alkalinity, color, ORP, TDS and EC. The effluent concentrations of Fe and Mn from the sand filter were less than 0.1 mg/L, which were below the concentrations on Korean drinking water quality standards (Fe, Mn < 0.30 mg/L). The influent $SO{_4}^{2-}$, concentrations were not noticeably changed during this ozone oxidation. Cr and Hg in the raw wastewater from the abandoned mining drainage were not detected in this study. The experimental result shows that the ozone oxidation of dissolved heavy metals and subsequent sand filtration of metal precipitates are desirable alternative for removing heavy metals in AMD.

• 대한화학회지
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• 제13권2호
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• pp.137-140
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• 1969

This investigation was made to evaluate the corrosion inhibiting effects of urotropine for mild steel in HCl. 1) Formaldehyde produced by the decomposition of urotropine also showed positive inhibiting effects. 2) In the presence of the ions, such as $Cu^+$, $Cu^{++}$, $Fe^{+++}$, $SO_3^=$, $SO_4^=$, $NO_2^-$, $NO_3^-$, $Cr_2O_7^=$, the inhibiting capacity of the urotropine was decreased. Alkali and alkaline-earth metal ions had no effects but the halogen ions improved it. 3) From measurements of polarization curves, it was assumed that the anode reaction was more retarded by the urotropine and the halogen.

• 자원환경지질
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• 제30권5호
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• pp.443-450
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• 1997

The main purpose of this study is to investigate mineralogical and chemical changes during natural weathering, and assess the mobility of major and trace elements. Yongwol power plant utilize anthracite coal which is mainly composed of illite, kaolinite, pyrophyllite and quartz in mineralogy. Coal and coal-derived fly ash samples were sampled by the electrostatic precipitator in Yongwol coal-fired power plant in Korea. Short term weathered fly ash were also collected in ash disposal mound, and two profile soil samples were taken from an ash near the power plant. Amorphous materials are the main component of the fly ash, and mullite, quartz, magnetite and heamatite are present in all coal-derived fly ash. In chemistry, Si and Al are the most abundant elements of the total content. The ash samples were fractionated into upper $90{\mu}m$ and under $45{\mu}m$ size. Finer particles show higher concentrations in metal contents including Co, Cr, Cu, Ni, V, Zn and Pb. Concentration of Zn and Pb are nearly 4 times higher concentration in the finer particles. For the profile samples, the concentrations of $SiO_2$, $Na_2O$, MgO and $K_2O$ generally show increasing trends with depth, whereas those of $Fe_2O_3$ and $TiO_2$ appear to decrease with depth. Content of MnO does not show any specific depth trend. For the trace elements, Co, Cu, Ni and V show increasing concentrations with depth.

• Bulletin of the Korean Chemical Society
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• 제23권8호
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• pp.1067-1072
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• 2002

A new polystyrene-divinylbenzene resin containing 2-(2-thiazolylazo)-5-dimethylamino-phenol (TAM) functional groups has been synthesized and its sorption behavior for nineteen metal ions, including Zr(Ⅳ),Hf(Ⅳ) and U(Ⅵ) has been investigated by batch and column methods. The chelating resin showed high sorption affinity for Zr(Ⅳ) at pH 1-5 and U(Ⅵ) at pH 4. Some parameters affecting the sorption of the metal ions have been detailed. The breakthrough and overall capacities were measured under optimized conditions. The overall capacities of Zr(Ⅳ), Th(Ⅳ) and U(Ⅵ), which showed higher than the other metal ions, were 0.90,0.84 and 0.80 mmol/g, respectively. The elution order of metal ions at pH 4 was evaluated as Zr(Ⅳ) > Th(Ⅳ) > U(Ⅵ) > Cu(Ⅱ) > Hf(Ⅳ) > W(Ⅵ) > Mo(Ⅵ) > In(Ⅲ) > Sn(Ⅳ) > Cr(Ⅲ) > V(Ⅴ) > Fe(Ⅲ). Quantitative recovery of most metal ions except Zr(Ⅳ) was achieved using 2M HNO3. Desorption and recovery of Zr(Ⅳ) was successfully performed with 2 M HClO4 and 2 M HCl.

• 자원환경지질
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• 제30권1호
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• pp.35-49
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• 1997

The coal formation of the Deokpyeong area are interbedded along metapelites of the Ogcheon Supergroup, which are composed mainly of graphite, quartz, muscovite and associated with small amounts of biotite, chlorite, pyrite and barite. The ratios of $SiO_2/Al_2O_3$, $Al_2O_3/Na_2O$ and $K_2O/Na_2O$ of the coaly metapelite are variable and wide range from 1.80 to 10.21, from 27.8 to 388.8 and from 7.6 to 61.8, respectively. These coal formation were deposited in basin of marine environments, and the REE of these rocks are not influenced with metamorphism and hydrothermal alterations on the basis of $Al_2O_3$ versus La, La against Ce, the ratios of La/Ce (0.19 to 0.99) and Th/U (0.02 to 4.75). These rocks also show much variation in $La_N/Yb_N$ (1.19 to 22.89), Th/Yb (0.14 to 21.43) and La/Th (0.44 to 13.67), and their origin is explained by derivation from a mixture of sedimentary and igneous rocks. The wide range in trace and REE element characteristics as Co/Th (0.12 to 2.78), La/Sc (0.33 to 10.18), Sc/Th (0.57 to 5.73), V/Ni (8 to 2347), Cr/V (0.02 to 0.67) and Ni/Co (1.56 to 32.95) of these coaly metapelites argues for inefficient mixing of the various source lithologies during sedimentation. Deep to pale green barium-vanadium muscovites (vanadium-oellacherite) have been found in this coal formations. Modes of occurrence and grain size of muscovite are heterogeneous, but most of the barium and vanadium-bearing muscovites occur along the boundaries between graphite and quartz grains, ranging from 200 to $350{\mu}m$ in length and from 40 to $60{\mu}m$ in width. Results of X-ray diffraction data of the minerals characterized to be monoclinic system with $a=5.249{\AA}$, $b=8.939{\AA}$, $c=20.924{\AA}$ and ${\beta}=95.894^{\circ}$. Representative chemical formula of the muscovite was $(Na_{0.09}K_{1.44}Ba_{0.46})(Al_{2.75}Ti_{0.07}V_{0.56}Fe_{0.08}Mg_{0.50})(Si_{6.12}Al_{1.88})O_{22}$. The V possibly substitute octahedral Al, and the Ba is coupled substitution of $K^+Si^{4+}=Ba^{2+}Na^+Ca^{2+}$, which compositional ranges of V and Ba are from 0.42 to 0.69 and from 0.34 to 0.56 based on $O_{22}$, respectively. Formation mechanism of the barium-vanadium muscovites in the coaly metapelite is shown that the formed by high pressure and temperature from regional metamorphism origanated during diagenesis at the interface between a basinal brine and organic matter.