• 대한핵의학회지
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• 제25권2호
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• pp.286-293
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• 1991

$^{123}I$, which is applied for the thyroid and other in vivo kinetic study, has a special role in life sciences. The 159 KeV $\gamma-ray$ from $^{123}I$ is almost ideally appropriate for the current imaging instrumentation. Its decay mode (electron capture) and short half-life (13.3 hr) reduced the burden of radiation dose to the patients, and its chemical property makes it easy to synthesize the labelling compounds. In this experiment, the production of $^{123}I$ via the nuclear reaction $^{124}Te(p,2n)^{123}I$ with 28 MeV protons was sutdied. $TeO_2$ is used as a target material, because it has good physical properties. The target was prepared with $TeO_2$ powder and was molten into a ellipsoidal cavity (a=14 mm, b=10 mm, $270.8mg/cm^2$ thick) of pure platinum. The irradiation was carried out in the external proton beam with incident energies range from 28 MeV to 22 MeV, and current was $30{\mu}A$. The loss of $TeO_2$ target was significantly reduced by using $4\pi-cooling$ system in irradiation. The dry distillation method was adopted for the separation of $^{123}I$ from irradiated target, and when it was kept 5 minutes at $780^{\circ}C$, its result was quantitative. The loss of the target material $(TeO_2)$ was below 0.2% for each production run and $^{123}I$ from the dry distillation apparatus was captured with 0.01 N NaOH in $Na^{123}I$ form, then the pH of the solution was adjusted to $7.5\sim9.0$ with HC1/NaOH. The $Na^{123}I$ solution was passed through $0.2{\mu}m$ membrane filter, and sterilized under high pressure and temperature for 30 minutes. The production of $^{123}I$ is acceptable for clinical application based on the quality of USP XXI.

• 한국식품과학회지
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• 제42권3호
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• pp.310-316
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• 2010

계란분말 제조 조건이 스펀지케이크의 특성 변화에 미치는 영향을 조사하기 위하여 분무건조 온도를 $70^{\circ}C$로 일정하게 하고, 비탈당 또는 탈당하여 pH를 달리하는 등으로 제조한 4종류의 계란분말과 상업용분무건조분말, 동결건조분말 등을 소재로 한 스펀지케이크를 제조하여 이들의 특성을 분석 하여 본 결과, 스펀지케이크의 특성을 높이는데 가장 적합한 소재로는 계란을 탈당한 뒤 $70^{\circ}C$에서 분무 건조시켜 제조한 계란분말이 가장 우수하였으며, 이 분말의 거품상태와 반죽상태에서의 비중은 각각 0.32와 0.42로 대조구와 비교하여 유의차가 나타나지 않았다. 동결건조분말의 경우 거품과 반죽 상태에서의 비중 및 케이크의 부피와 물성 등은 비교적 양호한 편이었으나 탈당시켜 분무건조온도를 $70^{\circ}C$로 하여 제조한 분말에는 미치지 못하였다. 그 외에 시료로 사용된 모든 계란분말은 거품이나 반죽상태에서의 비중이 크게 나타났고, 또한 제품의 관능검사 결과로 볼 때, 스펀지케이크 제조용 소재로는 부적합하다는 것을 알 수 있었다. 특히 상업용분무건조분말로 제조한 케이크는 모든 특성 면에서 크게 떨어지는 것으로 나타났다. 따라서 신선한 계란액을 탈당시킨 후 $70^{\circ}C$에서 분무 건조시켜 만든 분말이 스펀지케이크를 만드는데 있어 가장 적합한 소재로 확인되었다.

• 공업화학
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• 제9권1호
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• pp.13-19
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• 1998

Pyromellitic dianhydride(PMDA)와 methylenedianiline(MDA)을 기본으로 하고 이에 meta-phenylendiamine(MPD), para-phenylendiamine(PPD), 2,4,6-trimethyl-1,3-phenylenediamine(TriMeMPD)을 첨가하여 열적 이미드화법으로 서로 다른 화학적 구조를 갖는 폴리이미드 공중합체막을 합성하여 제조된 막들의 물성치들을 측정하고, 산소와 질소의 투과 특성을 막의 물성과 관련시켜 정성적으로 고찰하였다. PMDA-MDA막을 기준으로 PPD, MPD의 첨가는 막의 밀도를 증가시켰고, 이에 따라 막의 자유용적과 d-spacing 값의 감소를 나타내어 산소, 질소의 투과량을 감소시켰으며, TriMeMPD의 첨가는 반대의 경향을 나타내었다. 따라서 d-spacing값과 자유용적은 질소, 산소의 투과특성과 정성적 상관성을 가짐을 알 수 있었다. 모든 막에서 압력에 상관없이 투과 계수는 거의 일정한 값을 나타내었고, 막의 기체 투과계수가 증가하면 산소/질소의 이상분리인자는 감소하였다. 온도가 증가하면 투과량도 증가하였으며 이상분리인자는 감소하였으며, 질소 투과량의 상승비가 산소보다 더 크게 나타났다.

• 생명과학회지
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• 제27권8호
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• pp.930-936
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• 2017

Pseudomonas sp. GP32가 생산하는 생물고분자응집제 Biopol32의 실제 산업폐수에서의 적용을 위하여 생물고분자 Biopol32의 응집특성을 조사하였다. Biopol32의 응집물질은 polysaccharide로 확인되었다. 음이온성 응집제들은 응집효율을 높이기 위하여 보조응집제로 counter ion을 사용하고 있다. Biopol32의 응집활성은 보조응집제로 $Ca^{2+}$, $Al^{3+}$와 같은 양이온을 첨가 하였을 때 크게 증가하였으며, 보조응집제로서 7.0 mM $CaCl_2{\cdot}2H_2O$을 첨가하였을 때 Biopol32의 응집활성이 가장 높게 나타났다. Kaolin 현탁액에 Biopol32를 1.5 mg/l의 농도로 첨가하였을 때 가장 높은 응집활성을 보였다. Biopol32의 pH와 온도에 따른 응집활성은 현재 폐수처리 현장에서 상업적으로 이용되고 있는 음이온성 유기합성고분자응집제 polyacrylamide와 Zoogloea ramigera로부터 생산된 생물고분자응집제 zooglan과 응집활성을 비교하였다. Biopol32의 응집활성은 pH 5.0에서 8.0의 넓은 범위의 pH에서 높은 응집활성을 보였으며, 또한 온도의 영향에서는 $60^{\circ}C$에서 가장 높은 응집활성을 나타내었으나, $70^{\circ}C$ 이상의 온도에서는 응집활성이 급격히 감소하는 것으로 나타났다. Jar fermentor를 이용한 batch culture를 통하여 Biopol32의 응집활성과 전하밀도와의 관계를 조사하였다. 음이온성 전하밀도와 겉보기 점도가 높을수록 Biopol32의 응집활성이 높아져, Biopol32의 응집활성과 겉보기점도는 Biopol32의 전하밀도와 밀접한 관계가 있는 것으로 나타났다.

• 한국균학회지
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• 제39권1호
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• pp.39-43
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• 2011

큰느타리버섯 품종 육성을 위해 품질이 우수한 특성을 지니는 큰느타리버섯 KNR2312와 발이개체수가 적은 특성을 지니는 큰느타리버섯 KNR2539 모본으로부터 단핵균주를 분리 한 뒤 단포자간 교잡을 통해 발이개체수가 적은 고품질의 신품종 "단비"를 육성하였다. 신품종의 균사 생육 적정온도는 $25^{\circ}C$이며 자실체 발생 적정 온도는 $15{\sim}16^{\circ}C$였다. 솎음 재배에서 발이소요일수를 포함한 수확소요일수는 대조품종인 큰느타리버섯 3호에 비해 0.7~1.3일 정도 늦었다. 갓 색깔은 중간수준의 갈색이며 대 색깔은 흰색을 나타내었다. 갓모양은 우산형으로 갓 표면은 거미줄처럼 인피가 존재하며 850 cc 플라스틱 병재배에서 한 병당 수량은 $93{\pm}9.7$ g이었다. #8005 프라이머를 이용한 신품종 "단비"와 대조품종간의 RAPD 분석결과 서로 다른 DNA 밴드양상을 보여 주었다. 큰느타리버섯 신품종 "단비"의 경우 균긁기 후 발이개체수가 대조품종인 큰느타리버섯 3호에 비해 적은 특성이 있어 버섯 재배농가의 솎음 작업과정에 많은 도움을 줄 수 있을 것으로 기대된다.

• 폴리머
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• 제24권4호
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• pp.445-452
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• 2000

다양한 종류의 메탈로센 촉매와 공촉매인 개질-MAO (MMAO)을 이용한 에틸렌 (E)과 노르보르넨 (N)의 공중합에서 중합조건이 촉매 활성 및 공중합체의 구조와 성질 등에 미치는 영향을 조사하였다. 즉 $C_2$-대칭구조를 가지는 rac-Et(Ind)$_2$ZrC $l_2$, $M_2$Si(Ind)$_2$ZrC $l_2$, M $e_2$Si-(Cp)$_2$ZrC $l_2$ 및 $C_{s}$-대칭구조를 가지는 iPr(FluCp)ZrC $l_2$, 그리고 constrained geometry catalyst (CGC)와 이중다리 (di-bridged) 지르코노센 둥의 다양한 메탈로센 촉매를 사용하여 [N]/[E] 공급비에 따른 촉매 활성, 공중합체 (COC)의 열적 성질 및 N 함량을 조사하였다. rac-Et(Ind)$_2$ZrC $l_2$를 촉매로 사용한 경우에 공촉매의 몰비, 중합 온도 및 공촉매 종류 등의 중합조건을 조사한 결과 [Al]/[Zr]=3000, 4$0^{\circ}C$, MMAO 공촉매 등이 적합하였다. [N]/[E] 공급비가 증가됨에 따라 COC내의 N 함량이 증가하는 일반적인 경향을 보였으나, 촉매 활성은 사용된 메탈로센 촉매의 구조에 따라 달랐다. 즉 [N]/[E]가 증가할수록 $C_2$-대칭구조의 촉매 활성은 감소하였으나 $C_{s}$-대칭구조의 경우에는 증가하였다. 촉매활성과 N함량 등을 고려해 보면 rac-Et(Ind)$_2$ZrC $l_2$/MMAO계에서 비교적 높은 촉매 활성과 COC의 $T_{g}$제어가 용이한 결과를 얻을 수 있었다. 촉매종류에 따른 단량체의 반응성비를 Helen-Tudos 방법으로 구하였다.하였다.

• 한국재료학회지
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• 제21권2호
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• pp.111-114
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• 2011

As a growth-template of ZnO nanorods (NR), a hexagonal $\beta-Ni(OH)_2$ nanosheet (NS) was synthesized with the low temperature hydrothermal process and its microstructure was investigated using a high resolution scanning electron microscope and transmission electron microscope. Zinc nitrate hexahydrate was hydrolyzed by hexamethylenetetramine with the same mole ratio and various temperatures, growth times and total concentrations. The optimum hydrothermal processing condition for the best crystallinity of hexagonal $\beta-Ni(OH)_2$ NS was determined to be with 3.5 mM at $95^{\circ}C$ for 2 h. The prepared $Ni(OH)_2$ NSs were two dimensionally arrayed on a substrate using an air-water interface tapping method, and the quality of the array was evaluated using an X-ray diffractometer. Because of the similarity of the lattice parameter of the (0001) plane between ZnO (wurzite a = 0.325 nm, c = 0.521 nm) and hexagonal $\beta-Ni(OH)_2$ (brucite a = 0.313 nm, c = 0.461 nm) on the synthesized hexagonal $\beta-Ni(OH)_2$ NS, ZnO NRs were successfully grown without seeds. At 35 mM of divalent Zn ion, the entire hexagonal $\beta-Ni(OH)_2$ NSs were covered with ZnO NRs, and this result implies the possibility that ZnO NR can be grown epitaxially on hexagonal $\beta-Ni(OH)_2$ NS by a soluble process. After the thermal annealing process, $\beta-Ni(OH)_2$ changed into NiO, which has the property of a p-type semiconductor, and then ZnO and NiO formed a p-n junction for a large area light emitting diode.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.360-363
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• 2006

We synthesized $(La,\;Sr)MnO_{3+{\delta}$ as a cathode for SOFC by glycine nitrate process(GNP) and knew the different properties of $(La_{1-x}Sr_x)MnO_3$ by using nitrate solution and oxide solution as starting material. In case of using nitrate solution as a starting material, main crystal phase peak of $LaMnO_3$ increased as Sr content added up and a peak of $Sr_2MnO_4\;and\;La_2O_3$ was showed as a secondary phase. We added Mn excess to control a crystal phase. In this case, the electrical conductivity had a high value 210.3S/cm at $700^{\circ}C$ On the other side, when we used oxide solution as a starting material, we found main crystal phase of $LnMnO_3$ to increase as Sr content added up and a peak of $La_2O_3$ as a secondary phase. Similary, we added Mn excess to control a crystal phase in this case. We knew $(La,\;Sr)MnO_3$ powder to sinter well and the electrical conductivity of the sintered body at $1200^{\circ}C$ for 4hrs was 152.7s/cm at $700^{\circ}C$. The sintered $(La,\;Sr)MnO_3$ powder at $1000^{\circ}C$ for 4hrs got the deoxidization peak, depending on the temperature md in case of using nitrate solution as a start ing material the deoxidization peak was showed at $450^{\circ}C$ which is lower than used a oxide solution as a starting material. As a result, when $(La,\;Sr)MnO_3$ powder was synthesized to add Mn excess and to use nitrate solution as a starting material, we found it to have the higher deoxidization property and considered it as a cathode for m properly. And we found it to have different electrical conduct ivity the synthesized $(La,\;Sr)MnO_3$ powder by using different start ing materials like nitrate solution and oxide solution which influence a sintering density and crystal phase.

• Journal of Ginseng Research
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• 제37권1호
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• pp.124-134
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• 2013

The authentication of the physico-chemical properties of ginsenosides reference materials as well as qualitative and quantitative batch analytical data based on validated analytical procedures is a prerequisite for certifying good manufacturing practice (GMP). Ginsenoside Rb1 and Rg1, representing protopanaxadiol and protopanaxatriol ginsenosides, respectively, are accepted as marker substances in quality control standards worldwide. However, the current analytical methods for these two compounds recommended by Korean, Chinese, European, and Japanese pharmacopoeia do not apply to red ginseng preparations, particularly the extract, because of the relatively low content of the two agents in red ginseng compared to white ginseng. In manufacturing fresh ginseng into red ginseng products, ginseng roots are exposed to a high temperature for many hours, and the naturally occurring ginsenoside Rb1 and Rg1 are converted to artifact ginsenosides such as Rg3, Rg5, Rh1, and Rh2 during the heating process. The analysis of ginsenosides in commercially available ginseng products in Korea led us to propose the inclusion of the (20S)- and (20R)-ginsenoside Rg3, including ginsenoside Rb1 and Rg1, as additional reference materials for ginseng preparations. (20S)- and (20R)-ginsenoside Rg3 were isolated by Diaion HP-20 adsorption chromatography, silica gel flash chromatography, recrystallization, and preparative HPLC. HPLC fractions corresponding to those two ginsenosides were recrystallized in appropriate solvents for the analysis of physico-chemical properties. Documentation of those isolated ginsenosides was achieved according to the method proposed by Gaedcke and Steinhoff. The ginsenosides were subjected to analyses of their general characteristics, identification, purity, content quantification, and mass balance tests. The isolated ginsenosides showed 100% purity when determined by the three HPLC systems. Also, the water content was found to be 0.534% for (20S)-Rg3 and 0.920% for (20R)-Rg3, meaning that the net mass balances for (20S)-Rg3 and (20R)-Rg3 were 99.466% and 99.080%, respectively. From these results, we could assess and propose a full spectrum of physico-chemical properties of (20S)- and (20R)-ginsenoside Rg3 as standard reference materials for GMP-based quality control.

• 한국세라믹학회지
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• 제44권1호
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• pp.52-57
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• 2007

We synthesized $(La_{1-x}Sr_x)MnO_3$ as a cathode for SOFC by glycine nitrate process (GNP) and knew the different properties of $(La_{1-x}Sr_x)MnO_3$ by using nitrate solution and oxide solution as a starting material. In case of using nitrate solution as a starting material, main crystal phase peak of $LaMnO_3$ increased as Sr content added up and a peak of $Sr_2MnO_4\;and\;La_2O_3$ was showed as a secondary phase. We added Mn excess to control a crystal phase. In this case, the electrical conductivity had a high value 210.3 S/cm at $700^{\circ}C$. On the other side, when we used oxide solution as a starting material, we found main crystal phase of $LaMnO_3$ to increase as Sr content added up and a peak of $La_2O_3$ as a secondary phase. Similary, we added Mn excess to control a crystal phase in this case. We knew $(La,Sr)MnO_3$ powder to sinter well and the electrical conductivity of the sintered body at $1200^{\circ}C$ for 4 h was 152.7 S/cm at $700^{\circ}C$. The sintered $(La,Sr)MnO_3$ powder at $1000^{\circ}C$ for 4 h got the deoxidization peak, depending on the temperature and in case of using nitrate solution as a starting material, the deoxidization peak was showed at $450^{\circ}C$ which is lower than used a oxide solution as a starting material. As a result, when $(La,Sr)MnO_3$ powder was synthesized to add Mn excess and to use nitrate solution as a starting material, we found it to have the higher deoxidization property and considered it as a cathode for SOFC properly. And we found it to have different electrical conductivity the synthesized $(La,Sr)MnO_3$ powder by using different starting materials like nitrate solution and oxide solution which influence a sintering density and crystal phase.