• Fisheries and Aquatic Sciences
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• 제6권4호
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• pp.172-179
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• 2003

The safety of pufferfish (Lagocephalus gloveri) liver oil and the contents of some nutritional components were examined to obtain important information on their use as high valued functional foods. Pufferfish liver oil was extracted by the hot-water method using $1\%$ NaOH solution to remove toxic compounds, and then purified using a general purifying method of fish oil. Any extraordinary clinical symptoms were not observed from all groups administrated with pufferfish liver oil throughout the test period. None of the rats died when administrated the highest concentration of 10 mL/kg of the pufferfish liver oil. Vitamin A content was 114.2 ppm, as a retinal equivalent in the oil extracted using hot-water, but the content was higher (169.3 ppm) in oil extracted using n-hexane. Vitamin D and E were not detected in ppm in oil extracted using hot-water. Vitamin D in the pufferfish liver oil extracted using n-hexane was also undetected, but vitamin E was at 32.5 ppm. Among the 18 minerals detected, the sodium content was the highest at 253.5 ppm, followed by 13.9 ppm ofpotassium, 1.5 ppm of calcium, 0.2 ppm of magnesium, and other trace minerals. The contents of EPA and DHA were $0.8\%\;and\;14.8\%$, respectively, in the pufferfish liver oil extracted using hot-water. Considering these results, there is potential that pufferfish liver oil could be used as a functional food.

• 펄프종이기술
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• 제44권1호
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• pp.65-73
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• 2012

Nowadays, the concern on the environmental load of bleaching process gave rise to the process of ECF(elemental chlorine free) and TCF(total clorine free). These sequences are based on oxygen-derived compounds such as oxygen, ozone, and hydrogen peroxide which is used as a typical eco-friendly bleaching agent. In this study, paper mulberry pulp was bleached with hydrogen peroxide and some bleaching process were accompanied with ultrasonication in order to increase the bleaching efficiency. The best bleaching efficiency of paper mulberry pulp was obtained in the condition of hydrogen peroxide and ultrasonication(20 kHz) bleaching system at $45^{\circ}C$ for 30 min. The brightness and kappa number of paper mulberry pulp were gained to 5.09% and 3.52 respectively. and yield was slightly loosed to 2%. Therefore, the efficiency of hydrogen peroxide and ultrasonication bleaching system of paper mulberry pulp was superior to the conventional hydrogen peroxide bleaching system. Magnesium sulfate acted as a bleaching stabilizer for the increasement of yield. As a result, the yield and viscosity were increased to 2.2% and 12% respectively.

• 열처리공학회지
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• 제28권4호
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• pp.190-199
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• 2015

The study is intended to investigate the effect of solution treatment on microstructure and corrosion behavior of AZ91(Mg-9%Al-1%Zn-0.3%Mn)-2%Ca casting alloy. In as-cast state, the AZ91-2%Ca alloy consisted of intermetallic ${\beta}(Mg_{17}Al_{12})$, $Al_8Mn_5$ and $Al_2Ca$ phases in ${\alpha}-(Mg)$ matrix. After the solution treatment, Al within the ${\alpha}-(Mg)$ matrix was distributed more homogeneously, along with the slight decrease in the total amount of intermetallic compounds. The corrosion resistance of the AZ91-2%Ca alloy was improved after the solution treatment. The microstructural examinations for the solution-treated samples revealed that the better corrosion resistance may well be related to the incorporation of more oxides and hydroxides such as $Al_2O_3$, $Al(OH)_3$, CaO and $Ca(OH)_2$ into the surface corrosion product without dissolution of the intermetallic phases along the grain boundaries.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.815-820
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• 2011

Three kinds of organometallic compounds (chromium acetylacetonate, magnesium acetate and vanadyl acetylacetonate) were used as transition metal precursor, titanium n-butoxide and multi-walled carbon nanotube as titanium and carbon precursor to prepare metal oxide-CNT/$TiO^2$ composites. The surface properties and morphology of metal oxide-CNT/$TiO^2$ composites were by Brauer-Emett-Teller (BET) surface area measurement, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) analysis. The photocatalytic activity of prepared metal oxide-CNT/$TiO^2$ composites was determined by the degradation effect of methylene blue in an aqueous solution under irradiation of visible light.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.629-632
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• 2013

Many properties of inorganic compounds are sensitive to changes in the point-defect concentrations. In minerals, such changes are influenced by temperature, pressure, and chemical impurities. Olivines form an important class of minerals and are magnesium-rich solid solutions consisting of the orthosilicates forsterite $Mg_2SiO_4$ and the fayalite $Fe_2SiO_4$. Orthosilicates have an orthorhombic crystal structure and exhibit anisotropic electronic and ionic transport properties. We examined the anisotropy of the electrical conductivity of $Fe_2SiO_4$ under the assumption that the electronic conduction in $Fe_2SiO_4$ occurs via a small polaron hopping mechanism. The anisotropic electrical conductivity is well explained by the electron transfer integrals obtained from the spin dimer analysis based on tight-binding calculations. The latter analysis is expected to provide insight into the anisotropic electrical conductivities of other magnetic insulators of transition metal oxides.

• 한국산학기술학회논문지
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• 제14권1호
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• pp.493-498
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• 2013

합성 고분자 화합물의 생산과 ethanolamine(ETA, 원자력발전소에서 사용하는 pH 조절제)는 수질을 오염시키는 폐수를 발생한다. 본 연구는 유기물에 의해 유발된 COD를 감소시키기 위한 물리 화학적 처리법과 처리 약품을 개발하였다. $FeCl_2$와 $MgCl_2$를 1/1로 혼합하여 혼합응집제를 사용함이 COD 제거효율이 가장 좋은 결과를 얻었다. 유기물을 함유한 폐수처리에 복합응집제를 주입함으로써 COD제거율이 80%이상으로 나타났다.

• 한국응용과학기술학회지
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• 제13권1호
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• pp.11-19
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• 1996

The liposomes have been developed in many drugs and cosmetics fields. The liposomes prepared with main compounds of the intercellular lipids and lecithin. Amphiphile nonionic surfactants used for (PEG) n-sitosterol(n=5), diethanolamine cetylphosphate. The effect of gelation for liposomes have been on swelling reaction which have been mixed phospholipid with polyol-group at the high temperature. There were very good encapsulated properties of the active ingredients whether hydrophilic-group(magnesium ascorbyl phosphate, allantoin, sodium hyaluronate) and hydrophobic-group(vitamin-E acetate, vitamin-A palmitate). Optimum condition of liposomes were passed five times in the microfluidizer(700bar), wetting reaction temperature was at $95{\pm}5^{\circ}C$ for a hours. Particle size distribution of the vesicles should be within range 50-560nm(mean 200nm). The stability of liposomes for the course of time was stabilized for six months at $45^{\circ}C$. Application of the cosmetic was prepared moisturizing cream with liposomes of the phospholipid base.

• 한국식품영양과학회지
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• 제24권5호
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• pp.727-733
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• 1995

수액은 약리작용이 있다하여 민간요법으로 오랜기간 이용되어 왔으나 이에 관한 과학적인 연구는 의외로 적다. 더우기 요즈음은 환경오염이 심각해짐에 따라 자연 무공해 식품에 대한 관심이 증가하여 수액의 효율적인 이용이 절실히 요구되고 있는 실정이다. 따라서 본 실험에서는 자작나무류, 대나무류 및 다래나무 수액을 이용하여 천연 건강음료로 개발하기 위한 기초자료를 얻고져 무기물, 유리당, 아미노산, 핵산관련 물질 등을 분석하였다. 수액 중 무기물은 총 5종이 검출되었으며 이들의 함량은 칼슘, 칼륨이 월등히 많았고 다음으로 마그네슘, 나트륨, 철분의 순이었다. 특히 대나무류 수액에서 무기물이 풍부하여 칼슘이 242.0~422.1mg/L, 칼륨이 793.8~2504.1mg/L 및 마그네슘이 72.6~165.9mg/L로 높게 정량되었다. 유리당은 glucose, fructose, sucrose가 검출되었고, malrose는 검출되지 않았다. 자작나무 수액(#2)에서 glucose(42.1g/L), fructose(36.9g/L)가 가장 높게 검출되었다. 핵산관련 물질은 CMP, UMP가 정량되었고 GMP, IMP, AMP, hypoxanthine은 거의 검출되지 않았다. 아미노산은 18종 검출되었는데 총 아미노산은 2.4~30.4mg% 범위였으며, 주요 아미노산은 자작나무 수액(#1, #2)에서 taurine, glycine, lysine, alanine과 threonine이었으며, 거제수나무 수액(#3)과 물박달나무 수액(#4)에서는 glutamic acid와 lysine, 대나무 수액(#5, #6, #7)은 lysine, valine, alanine, serine, tyrosine과 glutamic acid였고, 다래나무 수액(#8)은 leucine과 alanin이었다.

• 한국작물학회지
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• 제51권5호
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• pp.401-407
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• 2006

본 시험은 논과 밭재배에 따른 양파생육 및 채종용 모구 생산, 저장력의 차이를 구명하고자 실시하였으며 그 결과는 다음과 같다. 1. 시험전후 토양의 화학적 성분을 보면 질소, 인산, 칼리는 밭토양에서 많았으며 칼슘, 마그네슘, 나트륨은 논토양에서 많았다. 토양수분은 논토양에서 많았고 지중온도는 밭 토양에서 높았다. 2. 양파의 지상부 생육은 밭재배가 양호했으나, 구의 발달은 월동이후 초기에는 논재배에서 빨랐으나 구 비대기 이후에는 밭재배가 더 컸다. 3. 구의 평균 무게는 밭재배가 무거으며, 양파구의 수분함량은 밭재배가 더 많았다. 경도는 논재배가 더 단단했으며 당도는 밭재배에서 더 높았다. 4. 양파의 무기성분 함량은 질소, 인산, 칼리는 밭재배에서 많았고 칼슘, 마그네슘, 나트륨은 논재배에서 많았다. 5. 구중 분포를 보면 밭재배에서는 구가 큰 양파가 많이 분포했으며 논재배에서는 작은 크기의 양파가 많이 분포하였고 양파 채종에 알맞은 모구 생산 비율은 논재배가 $63{\sim}70%$로 밭재배에 비해 $8{\sim}26%$ 더 많았다. 6. 부패율은 논재배가 $27.2{\sim}34.6%$이고 밭재배가 $37.5{\sim}51.4%$로 논재배가 $8.7{\sim}24.2%$ 적었다.

• 한국재료학회지
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• 제10권3호
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• pp.233-240
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• 2000

소결 촉진제 첨가없이 치밀한 코디어라이트 세라믹스를 얻기 위해 Mg-Al-Si계의 열적거동을 검토하였다. 수용액 매체에서 코디어라이트 현탁액의 분산안정성을 ESA를 이용하여 조사하였으며, 코디어라이트 졸의 응집 방지와 분산성을 부여하기 위해 2N $HNO_3$와 2N $NH_4OH$ 용액으로 pH 1.03과 pH 8.30로 조절하였다. pH 8.30인 코디어라이트 졸을 $150^{\circ}C$에서 12시간 건조한 시료에서 magnesium-aluminum-silicate 복합 겔이 존재하였다. 평형상태의 코디어라이트 겔의 결정화는 $1300^{\circ}C$ 이상의 소결 온도에서 존재하였으며, $1300^{\circ}C$ 이하의 조건에서는 ${\mu}-cordierite(Mg_2Al_4Si_5O_18)$, spine($MgAl_2O_4$) 및 mullite($Al_6Si_2O_{13}$)와 같은 다양한 준안정상이 복합적으로 혼재하였다. pH 1.03과 pH 8.30로 조절된 현탁액에서 코디어라이트 겔의 핵반응은 유사하게 일어났으나, 치말화거동은 졸의 pH에 상당한 차이를 보였다. pH 1.03인 졸 보다 pH 8.30인 졸의 치밀화가 더욱 진전되었다.