• 생명과학회지
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• 제14권3호
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• pp.441-444
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• 2004

본 연구는 피브린의 무게를 측정하는 방법에 의하여 간단하고 단순하게 트롬빈활성을 측정하는 방법을 확립하기 위하여 수행되었다. 이 새로운 트롬빈측정 법은 트롬빈이 기질인 피브리노겐과 반응 후 생성된 피브린의 무게를 측정한다. 피브린의 생성은 사용한 트롬빈의 효소활성, 반응온도, 반응시간 및 원심분리의 시간에 의존하였다. 피브린의 생성은 37$^{\circ}C$에서 트롬빈활성이 1.0 unit/ml 이내, 4.0mg/ml의 피브리노겐 농도 및 반응시간이 5분 이내에는 직선적으로 증가하였다. 그리고 생성된 피브린은 3,000$\times$g에서 5분간 원심분리의 경우에 안정하였다. 이 새로운 피브린 측정 법은 트롬빈을 저해하는 천연물질을 탐색하는데 유행하게 사용될 것으로 기대된다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2010년도 춘계학술발표대회
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• pp.37.1-37.1
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• 2010

The multi-component olivine cathode material, $LiMn_{1/3}Fe_{1/3}Co_{1/3}PO_4$, was prepared via a novel coprecipitation method of the mixed transition metal oxalate, $Mn_{1/3}Fe_{1/3}Co_{1/3}(C_2O_4){\cdot}2H_2O$. The stoichiometric ratio and distribution of transition metals in the oxalate, therefore, in the olivine product, was affected sensitively by the environments in the coprecipitation process, while they are the important factors in determining the electrochemical property of electrode materials with multiple transition metals. The effect of the pH, atmosphere, temperature, and aging time was investigated thoroughly with respect to the atomic ratio of transition metals, phase purity, and morphology of the mixed transition metal oxalate. The electrochemical activity of each transition metal in the olivine synthesized through this method clearly was enhanced as indicated in the cyclic voltammetry (CV) and galvanostatic charge/discharge measurement. Three distinctive contributions from Mn, Fe, and Co redox couples were detected reversibly in multiple charge and discharge processes. The first discharge capacity at the C/5 rate was $140.5\;mAh\;g^{-1}$ with good cycle retention. The rate capability test showed that the high capacity still is retained even at the 4C and 6C rates with 102 and $81\;mAh\;g^{-1}$, respectively.

• 대한수의학회지
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• 제36권3호
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• pp.541-550
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• 1996

Tetracycline antibiotics have been widely used not only therapeutics but feed additives. There are many methods for the isolation and determination of tetracycline antibiotics in animal muscle tissue. But those methods take much time and labor, so it is difficult to analyse many samples simultaneously. A rapid isolation method and liquid chromatographic determination of tetracycline antibiotics in animal muscle tissue (bovine, porcine, chicken) is presented. Blank control and tetracyclines fortified samples (0.5g) were blended with $C_{18}$ containing 0.05g each of oxalic acid and disodium ethylenediaminetetraacetate. After homogenize, homogenate was transferred to glass column made from 10ml glass syringe and compressed to 4~4.5ml volume. A column made from the $C_{18}$/meat matrix was washed with hexane (8ml) and dichloromethane (8ml, if needed), following which the tetracyclines were eluted,vith methanol or 0.01M methanolic oxalic acid (8ml). The eluates containing tetracyclines analytes were free from interfering compounds when analysed by HPLC with UV detection (photodiode array at 360nm). Standard curve for each tetracycline showed a linear response at the range of $0.05{\sim}1.0{\mu}g/ml$ and tetracycline antibiotics were eluted within 4ml of eluted volume. All tetracycline antibiotics except tetracycline were stable during the concentration process at $40^{\circ}C$ and time required for concentration was 3~4 hours. Fortified samples containing oxalic aicd and EDTA represented more good recoveries than those of not-contained sample. Recoveries were 91.8~110.1% (oxytetracycline; OTC), 57.7~79.5% (tetracycline; TC), 78.1~88.6% (chlortetracyclines; CTC) and 88.4~100.6% (doxycycline; DC) in pork tissue, 101.1~126.8% (OTC), 66.4~75.4% (TC), 79.2~88.1% (CTC) and 69.3~86.7% (DC) in beef tissue, and 90.8~95.6% (OTC), 66.2~84.4% (TC), 75.7~77.2% (CTC) and 55.6~80.7% (DC) in chicken muscle tissue. The detection limits validated in muscle tissue by this method were $0.05{\mu}g/g$ for OTC and TC, and $0.1{\mu}g/g$ for CTC and DC.

• 대한화학회지
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• 제18권5호
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• pp.320-328
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• 1974

종래의 방법으로 고압하에서 전지의 표준기전력 $(E^{\circ})$를 산출하는 것은 불가능하다. 그러나 완전평형상수의 개념을 종래의 Nernst 방정식에 적용하므로서 고압하에서 표준기전력을 구할 수 있게 되었다(완전 Nernst방정식). 더욱이 다른 열역학적 성질 이를테면 수화수의 순변화(k), 용매의 압축을(${\beta}$), 전지반응에서 종래의 해리상수(K) 평형상태에서 표준자유에너지변화(${\Delta}G^{\circ}$) 표준엔탈피변화(${\Delta}H^{\circ}$) 및 표준엔트로피변화($S^{\circ}$) 등을 얻었다. 본 실험에서는 전지의 기전력(E)을 $20{\sim}35^{\circ}C$와 1∼2500 atms 범위에서 측정하였다. 일정한 온도에서 전지의 기전력은 압력이 증가함에 따라 증가하였으며, 일정한 압력에서 온도가 증가함에 따라 역시 증가하였다. 전지반응의 수화수의 순변화(k)는 $20^{\circ}C$에서 41.96으로서 압력에 따라 변하지 않고 일정한 값을 유지하였으나 한편 K와 ${\Delta}S^{\circ}C$는 압력에 따라 증가하였으나 ${\Delta}G^{\circ}$와 ${\Delta}H^{\circ}$는 감소하였다. 고압하에서도 완전 Nernst방정식으로부터 표준기전력을 계산할 수 있으므로 상압에서와 마찬가지로 화학평형론을 취급할 수 있게 되었다

• 한국버섯학회지
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• 제12권4호
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• pp.299-303
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• 2014

이번 연구에서는 식용 및 약용버섯 자실체를 가지고 버섯의 주요 기능성 성분인 총 당의 함량을 추출방법을 달리하여 비교분석하였다. 열수추출, 산추출, 알칼리 추출을 통해 총 당 측정법으로 미량의 시료에 적합한 페놀-황산법으로 측정하였다. 표준 곡선은 glucose solution을 사용하여 작성하고 측정한 흡광도를 표준곡선에 적용하여 시료의 농도를 얻었다. 열수추출에서는 동충하초가 658.4(${\mu}g/g$)로 가장 높았고, 산추출과 알칼리 추출에서는 운지버섯이 각각 649.7(${\mu}g/g$)와 679.0(${\mu}g/g$)로 가장 높음을 알 수 있었다. 추출방법별로 열수추출과 마이크로웨이브 추출로 총 당 함량을 정량한 결과 열수 추출에서는 동충하초, ASI 7025가 높았고, 1 hr 마이크로웨이브 추출 및 2 hr 마이크로웨이브 추출에서는 운지버섯, 꽃송이가 높게 나타났다. 이러한 결과를 통해 각기 다른 추출용매와 추출방법에 따라서 추출되는 총 당 함량이 다름을 알 수 있었다.

• Reproductive and Developmental Biology
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• 제35권1호
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• pp.93-97
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• 2011

Previously, we reported that the osmolarity conditions in the satellite region were affected CpG DNA methylation status while Pre-1 sequence was not affected CpG DNA methylation in pNT blastocyst stage. This study was conducted to investigate the DNA methylation status of repeat sequences in pig nuclear transfer (pNT) embryos produced under different osmolarity culture conditions. Control group of pNT embryos was cultured in PZM-3 for six days. Other two treatment groups of pNT embryos were cultured in modified PZM-3 with 138 mM NaCl or 0.05 M sucrose (mPZM-3, 320 mOsmol) for two days, and then cultured in PZM-3 (270 mOsmol) for four days. The DNA methylation status of the Pre-1 sequences in blastocysts was characterized using a bisulfite-sequencing method. Intriguingly, in the present study, we found the unique DNA methylation at several non-CpG sequences at the Pre-1 sequences in all groups. The non-CpG methylation was hypermethylated in all three groups, including in vivo group (86.90% of PZM-3; 83.87% of NaCl; 84.82% of sucrose; 90.94% of in vivo embryos). To determine whether certain non-CpG methylated sites were preferentially methylated, we also investigated the methylation degree of CpA, CpT and CpC. Excepting in vivo group, preference of methylation was CpT>CpC>CpA in all three groups investigated. These results indicate that DNA methylation of Pre-1 sequences was hypermethylated in CpG as well as non-CpG site, regardless modification of osmolarity in a culture media.

• 한국약용작물학회지
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• 제22권6호
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• pp.497-503
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• 2014

In order to produce the high quality of dried-ear mushroom, various drying methods such as hot-air drying at $40{\sim}80^{\circ}C$, freeze drying and drying in vinyl house were carried out. Drying hours of hot-air drying, freeze drying and drying in vinyl house were 12.5~21.5, 36.0 and 72.0 hrs, respectively. Vitamin $D_2$ content of sample was the highest as $6.77{\mu}g/g$ DW in drying in vinyl house and then followed by freeze drying as $5.90{\mu}g/g$ DW and hot-air drying as $1.89{\sim}5.01{\mu}g/g$ DW. After dry, external appearance and color of mushrooms applied hot-air drying and drying in vinyl house were better than freeze-dried one. After rehydration, water uptake of sample in drying in vinyl house and hot-air drying at $50{\sim}60^{\circ}C$ were 17.8 and 19.3~21.0 times, respectively. The methods of drying in vinyl house and hot-air drying at $50{\sim}60^{\circ}C$ also led to high hardness, good shape and resilience. As the results of production of dried-ear mushroom with high quality, we suggest that the best method for drying is the drying in vinyl house due to not only high vitamin $D_2$ content, good external appearance and color after drying but also high hardness and good shape after rehydration.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 추계학술대회 논문집
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• pp.157-160
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• 2008

색온도 및 광색 가변형 100W RGBY LED 투광기를 개발하기 위하여, 투광기의 광학 및 방열기구를 설계하였다. 또한 100W LED 광원모듈을 구동하기 위한 구동회로와 색온도 및 광색 가변을 위한 제어회로를 개발하였다. 이와 같은 설계결과를 적용하여 100W RGBY 투광기의 시제품을 제작하였고, 시제품의 광학적 성능은 협각 $20^{\circ}$, 중각 $50^{\circ}$, 광각 $75^{\circ}$이상을 만족시켰다. 또한 색온도의 변화는 CIE 1931 색좌표에서 흑체궤적과 일치하여 $2,000K{\sim}10,000K$까지 변화하도록 R,G,B,Y LED의 Duty Ratio를 설정하였다. 또한 방열 특성은 100W 구동시 녹색 LED의 온도는 $37{\sim}41.3^{\circ}C$, heatsink의 온도는 $34{\sim}35^{\circ}C$에서 동작되도록 하였다.

• 한국재료학회지
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• 제5권8호
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• pp.1035-1039
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• 1995

경북 감포지역에서 산출되는 천연 벤토나이트를 이용하여 제올라이트를 합성하였으며 세제용 builder로서 가능성을 연구하였다. 최적의 합성조건은 기질의 몰비가 SiO$_2$/Al$_2$O$_3$=2, $Na_2$O$_3$/Al$_2$O$_3$=1, $H_2O$/A1$_2$O$_3$=30이고 9$0^{\circ}C$에서 3시간 반응시킬 경우였고, 이 조건에서는 A형 제올라이트가 합성되는 것을 XRD를 통하여 확인하였다. 최적 조건에서 합성된 제올라이트의 이온교환능을 측정하기 위하여 경도 40$^{\circ}$Dh의 CaCl$_2$용액과 3$0^{\circ}C$에서 IS분 접촉시킨 결과 264.9mg CaO/g-zeolite 정도로 우수한 값을 나타내었다. 이 시료의 백색도는 89%이었고, 평균 입자크기는 9.95$\mu\textrm{m}$이었다.

• 한국태양에너지학회 논문집
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• 제38권1호
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• pp.45-55
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• 2018

Environmentally benign lead-free solder coated ribbon (e. g. SnCu, SnZn, SnBi${\cdots}$) has been intensively studied to interconnect cells without lead mixed ribbon (e. g. SnPb) in the crystalline silicon(c-Si) photovoltaic modules. However, high melting point (> $200^{\circ}C$) of non-lead based solder provokes increased thermo-mechanical stress during its soldering process, which causes early degradation of PV module with it. Hence, we proposed low-temperature conductive paste (CP) based tabbing method for lead-free ribbon. Modules, interconnected by the lead-free solder (SnCu) employing CP approach, exhibits similar output without increased resistivity losses at initial condition, in comparison with traditional high temperature soldering method. Moreover, 400 cycles (2,000 hour) of thermal cycle test reveals that the module integrated by CP approach withstands thermo-mechanical stress. Furthermore, this approach guarantees strong mechanical adhesion (peel strength of ~ 2 N) between cell and lead-free ribbons. Therefore, the CP based tabbing process for lead free ribbons enables to interconnect cells in c-Si PV module, without deteriorating its performance.