• 한국축산식품학회지
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• 제18권4호
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• pp.316-321
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• 1998

In this study, we carried out to isolate lactoferrin from Korean native cattle and Holstein cow by batch extraction, ion exchange chromatography, gel filtration, and affinity chromatography. The purity of the isolated lactoferrin was higher than that of lactoferrin purchased from Sigma, when determined by SDS-PAGE and HPLC analysis. Antibacterial activity of E. coli O111 by Korean native cattle lactoferrin was lower than that of Holstein lactoferrin. A minimal inhibitory concentration(MIC) of Korean native cattle lactoferrin and Holstein lactoferrin was 2.75 mg/ ml and 1.5 mg/ml respectively. The lactoferrin hydrolyzate of Korean native cattle exhibited antimicrobial activity at 0.25 mg/ml, whereas that of Holstein cow exhibited antimicrobial activity at 0.12 mg/ml. The antibacterial potency of the hydrolyzate was at least tenfold greater than that of undigeated lactoferrin with strains tested. The effect of hydrolyzate was bactericidal as indicated by rapid loss of viability of E. coli O111.

• 한국세라믹학회지
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• 제35권6호
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• pp.529-534
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• 1998

Agglomeration-free indium oxide particles were produced by ultrasonic pyrolysis of indium nitrate(3 hy-drate) solution. Th mean size of particles was increased from 3 $\mu\textrm{m}$ to 11$\mu\textrm{m}$ with increasing intial con-centrations of indium nitrate from 0.05mol% to 4.83 mol% When the input rate of indium nitrate solution was increased from 0.1 cm3/min to 0.8cm3/min the size of particles remained same and only the pro-duction rate of particles was increased. At 300$^{\circ}C$ the particles were white color with low crystallinity. But the color turned into yellow with increasing reaction temperature. The change of particle size was not ob-served with increasing temperatuer up to 700$^{\circ}C$ IR spectrum and TGA analysis confirmed that the purity of indium oxide was increased with temperature of reaction.

• 한국세라믹학회지
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• 제25권6호
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• pp.585-592
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• 1988

Aluminum sec-butoxide was synthesized from aluminum foil and alcohol. The characteristics of the alumina powder prepared from the synthesized alkoxide by the Yoldas method were studied. As a result of measuring the synthesized aluminum sec-butoxide by GC, the purity of the synthesized alkoxide was 98.7% on the basis of commercial alkoxide and the yield was 78.5%. A127-MASNMR analysis shows that powders dried at 9$0^{\circ}C$ and $\alpha$-Al2O3 have 6-cordinated structure and ${\gamma}$-Al2O3 has 4-coordinated structure. The characteristics of alumina powder prepared from the synthisized alkoxide showed the same characteristics with the alumina powder prepared from the commercial alkoxide.

• 대한전기학회논문지
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• 제41권7호
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• pp.753-759
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• 1992

For the fabrication of the microscale memory or electrical devices, Langmuir-Blodgett(LB) method is the most possible candidate. N-Alkylquinolium-TCNQ compounds were synthesized. The structure of the compounds were identified by the NMR spectroscopy and the purity were checked to be good by the elemental analysis. The surface pressure($\pi$) was measured at the air-water interface. The isotherm showed two transitions at 30mN/m and 45mN/m. The LB films were deposited by the home-made Kuhn type apparatus. The transfer ratio($\tau$) of the deposition was more than 0.95 for the up-stroke and less than 0.4 for the down-stroke. The absorbance peaks of the LB films appear at around 420nm and 700-820nm.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.367-368
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• 2007

To investigate the 2nO thin films which are interested in the next generation of short wavelength LEDs and Lasers and UV photodetector with p-type inversion layer, the ZnO thin films were deposited by RF sputtering system. Gas ratios and work pressure is Ar : $O_2$ = 4 : 1 and 15 mTorr, respectively, and the purity of ZnO target is 5N. The ZnO thin films were deposited at 300, 450, and $650^{\circ}C$. The current-voltage, responsivity and quantum efficiency of devices were studied and compared with each devices.

• KSBB Journal
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• 제27권1호
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• pp.33-39
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• 2012

In this study three major curcuminoids in turmeric curcumin (1), demethoxycurcumin (2) and bismethoxycurcumin (3) were efficiently extracted by optimizing extraction condition and simultaneously identified using a fast and reliable RP-HPLC-UV-MS and TLC method. The analysis by the $C_{18}$ column was performed and the UV wavelength was fixed at 425 nm. In this result, the total extraction yield of turmeric (Curcuma longa) was increased with extraction time from 1 to 7 h. So, optimum extraction time is 4 h. Also, the highest yield of extraction amount 0.433g 8.66% was obtained by ultrasonic waves with quarter frequency kHz and an extraction time of 7 h. The experiment method was consistent with theoretical Value $r^2$ = 0.987 (1), 0.997 (2) and 0.998 (3). Moreover, LC-MS analysis provided efficiently molecular weight information of three major curcuminoids in turmeric extracts and high purity (~95%) of the curcuminoids were obtained. This work offers would be useful for chemical and biological studies of natural plants and its products.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.2999-3005
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• 2022

The new experimental setup has been built at the 11b channel of the IBR-2 research reactor at FLNP, JINR, to study the elemental composition of samples by registration of prompt gamma emission during thermal neutron capture. The setup consists of a curved mirror neutron guide and a radiation-resistant HPGe high-purity germanium detector. The detector is surrounded by lead shielding to suppress the natural background gamma level. The sample is placed in a vacuum channel and surrounded by a LiF shield to suppress the gamma background generated by scattered neutrons. This work presents characteristics of the experimental setup. An example of hydrogen concentration determining in a diamond powder made by detonation synthesis is given and on its basis, the sensitivity of the setup is calculated being ~4 ㎍.

• 전자공학회논문지D
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• 제36D권7호
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• pp.17-25
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• 1999

PECVD 법을 이용하여 Tungsten Nitride($WN_x$) 박막을 $WSi_3N_4$ 기판위에 형성하였다. $WN_x$ 박막은 기관온도, 가스의 유량, rf power 등의 공정변수를 변화시키면서 형성되었고, 서로 다른 질소원으로 $NH_3$와 $N_2$를 각각 사용하여 박막의 특성을 조사하였다. $WN_x$ 막 내의 질소함량은 $NH_3$와 $N_2$의 유량에 따라 0~45% 정도로 변화하였으며, $NH_3$를 사용하였을 때, 최고 160nm/min의 높은 성장률을 나타내었다. $WSi_3N_4$ 기판 위에서는 TiN이나 Si 위에서보다 높은 성장률을 나타내었다. $WN_x$ 박막의 순도를 AES로 측정해 본 결과 $NH_3$를 사용했을 때 고순도의 박막을 얻을 수 있었다. XRD 분석으로 순수한 다결정의 W가 비정질의 $WN_x$로 변화되는 것을 알 수 있었으며, 이것은 $WN_x$가 식각 공정시 미세 패턴 형성이 W보다 유리할 것이라는 것을 보여준다. TiN, NiCr, Al 등의 다양한 기판 위에 형성해 본 결과 Al 위에서 최대 $1.6 {\mu}m$의 두꺼운 막이 형성되었다.

• 한국광물학회지
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• 제30권4호
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• pp.137-147
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• 2017

본 연구에서는 저품위 견운모를 대상으로 파쇄, 해쇄 및 침강분리 공정을 적용하여 각각의 단위공정의 특성과 품위향상에 미치는 영향에 대해 고찰하였다. 원광석의 주 구성광물은 견운모, 석영, 방해석이었으며, 체가름 결과, 입자의 크기가 작아질수록 견운모의 함량은 높아지는 반면, 불순광물의 함량은 상대적으로 감소하는 경향을 보였다. 조암광물의 형상 및 원소분석 결과, 메디아를 이용하는 분쇄 방식보다는 입자의 표면에 선택적으로 충격력과 전단력을 가해줄 수 있는 해쇄 방식이 적절한 것으로 판단되었다. 해쇄 시간 및 슬러리 농도가 증가함에 따라 미립자 발생량이 증가하였으며, 장시간 해쇄한 경우 미립자 내 불순광물인 석영과 방해석의 혼입량이 증가하는 결과를 보였다. 해쇄 없이 단순하게 분산한 슬러리를 20분 동안 정치 후 회수한 정광의 생산율은 15.4 wt%, $K_2O$ 함량은 9.84 wt% 였다. 10분 해쇄한 후 40분 침강 분리하여 회수한 정광의 생산율은 23.4 wt%로 증가한 반면 $K_2O$ 함량은 9.71 wt%로 감소하였다. 회수된 최종산물은 대부분 판상의 입자로 관찰되었으며 입자표면의 원소분석 결과, 주 구성 원소는 Si, Al, K로 견운모의 화학조성을 보였다.

• 한국환경과학회지
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• 제25권2호
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• pp.331-336
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• 2016

In this study the optimum conditions for recovery of valuable metal in Electric Arc Furnace Dusts were investigated. 2M of $H_2SO_4$, 1~5 of solid/liquid ratio, 0~180 min of leaching time has been established for leaching condition, and for electrowinning, each of Pt, C, Zn, Pb anode and Zn, Cu cathode was compared respectively at pH 2, 4 and 6. The result of elemental analysis of Zn crystal, a lagre quantity of Fe and H has been observed with Zn and other heavy metal, therefore, impurities removing process would be requir for enhancing purity of Zn. As the result, about 60% of Zn has been recovered under condition of 2 M of $H_2SO_4$, 1:2 of S/L ratio at 120 min, and Pt or Pb for anode, Zn for cathode has been shown the highest efficiency of electrowinning at pH 6.