• Bulletin of the Korean Chemical Society
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• 제29권6호
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• pp.1185-1189
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• 2008

Two HPLC methods such as cefadroxil and cefalexin methods were compared in their performance for the quantitative analysis of the content and purity of $\beta$ -lactamic antibiotic, cefradine, for six bulk drug samples. Between the two methods, the cefadroxil method prescribed by the European Pharmacopoeia (EP) for the determination of impurities in cefradoxil was superior to the cefalexin method prescribed by the EP and by the United States Pharmacopeia (USP) for the determination of cefalexin impurity in cefradine in terms of the greater stability of the chromatogram baselines and the higher precision, i.e., the lower % relative standard deviation (RSD). Based on the comparison of the two HPLC methods, the cefadroxil method was recommended to replace the TLC method, which has been prescribed by the EP as the official method for determination of extraneous impurities in cefradine.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.223-226
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• 2004

The importance of a proper sample preparation and analysis technique has getting attention due to the complicity of toxic elements of interest from environmental samples depend on analytical purposes. It is critical to use proper analytical method to evaluate trace elements concentration in many environmental samples especially for making remediation decisions. Therefore, it is critical to apply a proper sampling and analytical method such as EPA publication SW-846 (Test Methods for Evaluating Solid Waste, Physical/chemical Methods). The objective of this study was to compare the USEPA Methods 3050B, modified 3050B, 305 la, and KBSI method (modified EPA 3052 Method) in term of recovery rate of metals. The NIST SRM (Montana soil) was used to compare the extraction and digestion efficiency. After sample has been collected the analysis were achieved by ICP-MS (Elan 6100, Perkin Elmer) as well as ICP-AES (Ultima 2C, JY) for trace elements and major elements.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2002년도 추계학술대회
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• pp.203-205
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• 2002

Light is an environmental signal that regulates photomovement and main energy source of photosynthesis in the cyanobacterium Synechocystis sp. PCC 6803 (Syn6803). Syn6803 is a popular model system for study of plant functional genomics. In this report, we adopted 2D gel based proteomics study to investigate proteins related with the light absorption and photo-protection in Syn6803. More than 700 proteins were detected on the SDS-gels stained with silver nitrate. Several proteins showing different expression level under various light conditions were identified with MALDI-TOF Mass spectrometry. As a comparison, we also conducted ICAT-based proteome study using WT and cphl (cyanobacterial phytochrome 1) mutant. A cphl deletion led to changes in the expression of proteins involved in translation, photosynthesis including photosystem and CO2 fixation, and cellular regulation. We are currently involved in TAP-tagging method to study protein-protein interactions in search for the molecular component involved in the light signal transduction of Syn6803 photomovement.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.235.2-236
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• 2002

The alkylphenols, chlorophenols and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring mode followed by three work-up methods for comparison: EPA method, isoBOC derivatization method and TBDMS derivatization method. Eleven phenols in water samples were extracted with dichloromethane. (omitted)

• 한국광물학회지
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• 제23권1호
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• pp.85-91
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• 2010

NIST 표준시료인 SRM 2710(Montana Soil)을 대상으로, 중금속의 지화학적 존재형태 연구에 일반적으로 적용되는 Tessier 연속추출법과 최근 소개된 초음파연속추출법을 적용 및 비교하여 오염 토양 내 중금속의 효율적 분석방법을 제시하고자 하였다. As, Cd, Cu, Pb, Zn의 총함량을 USEPA Method 3050B, KBSI Method, 초음파 추출법을 적용하여 분석한 결과, 모두 공인 분석값에 가까운 값으로 측정되었다. Tessier 연속추출법과 초음파 연속추출법의 비교 결과, 원소별 및 단계별 추출 양상과 추출효율이 두 방법 모두 거의 동일한 것으로 나타났다. 초음파 연속추출에는 총 3시간 정도 소요되었으며, 기존의 Tessier 연속추출법의 12시간 정도와 비교할 때 크게 단축되었다. 유기오염 시료의 전처리법으로 흔히 사용되는 초음파 추출법은 비교적 짧은 시간 내 추출이 이루어지고, 고온의 가열이 필요치 않으며, 시료에 직접 강한 파장을 주어 추출하기 때문에 비교적 높은 추출효율을 보이는 효과적인 방법이라 할 수 있다.

• 암석학회지
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• 제21권4호
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• pp.431-439
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• 2012

원소의 고순도분리는 동위원소계 연구의 기초가 된다. 이 기술보고에서는 Sm-Nd 연대측정법에 중요한 원소군인 Sm과 Nd의 원소분리에 자주 이용되고 있는 HDEHP를 이용한 테플론분말(란탄-레진)법과 Sm-Nd 동위원소계 및 La-Ce 동위원소계의 연구를 위한 원소분리법인 ${\alpha}$-HIBA(${\alpha}$-Hydroxy Isobutyric acid)법의 장단점을 한국지질자원연구원(KIGAM), 기초과학지원연구원(KBSI), 극지연구소(KOPRI) 및 일본 나고야대학과 같은 각 기관별 용리곡선을 통해 비교 소개하였다. 동위원소 지구화학연구를 위한 이 고순도의 원소분리법 비교는 Sm-Nd계 및 La-Ce계 동위원소 지구화학연구자의 실험법 선택에 많은 도움을 줄 것이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.397_398
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• 2009

Demonstrations to deploy high temperature superconducting (HTS) cable to the real gird are actively carried out throughout the world. Power utilities have an interest in the inherent advantage of the HTS cable system, and achieve the expected results from the series of verification test. To embody the reliability in the phenomenon occurred commonly in three-phase system, we simulate the load unbalance. A 22.9 kV large scale HTS cable system with the specification of 100 m-long, 50 MVA capacity has been tested with up to 30% unbalance rate. To evaluate the effect of AC loss increase due to the unbalanced load, the cooling loads are measured by the calorimetry method. In this paper, the correlation between AC loss and load unbalance is described and investigated precisely.

• 한국세라믹학회지
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• 제43권1호
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• pp.22-27
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• 2006

The electronic band structures of Metal-doped titanium dioxide, M-doped $TiO_2$ (M=Co, Cr, Fe), have been studied by using XRD, UV-vis diffuse reflectance spectrometer and FP-LAPW (Full-Potential Linearized Augmented-Plane-Wave) method. The UV-vis of M-doped $TiO_2$ (M=Co, Cr, Fe) showed two absorption edges; the main edge due to the titanium dioxide at 387 nm and a shoulder due to the doped metals at around 560 nm. The band gap energies of Co, Cr and Fe-doped $TiO_2$ calculated by FP-LAPW method were 2.6, 2.0, and 2.5 eV, respectively. The theoretically calculated band gap energy of $TiO_2$ by using FP-LAPW method was the same as experimental results. FP-LAPW method will be useful for fabrication and development of photo catalysts working under visible light.

• 한국결정학회지
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• 제16권2호
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• pp.141-148
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• 2005

It is well known that the general metals have a lot of grain boundaries. The grain boundaries play a negative role to increase the resistivity and to decrease the conductivity. The small resistivity and the large conductivity have been a goal of the material scientists, and no signal noise, perfect signal transfer, and the realization of the real sound are the dream of electronic engineers and audio manias. Generally, oxygen free copper (OFC) and Ohno continuous casting (OCC) copper cables have been used for the purpose of the precise signal transfer and low noise. However they still include a lot of grain boundaries. In our study, we have grown the single crystal by the Czochralski method and succeeded to produce single crystal wires from the crystal in the dimension of $0.5{\times}0.5{\times}2500mm$. The produced wire still possesses very good single crystal properties. We observed the structure of the wire, and measured the resistance and impedance. Glow Discharge Spectrometer (GDS) was used for analyzing the compositions of copper single crystals and commercial copper. Current-Voltage curve, resistance, total harmonic distortion and speaker frequency response were measured for comparing electrical and acoustic properties of two samples.

• 한국수산과학회지
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• 제53권5호
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• pp.707-716
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• 2020

Red sea cucumber Stichopus japonicus, was dried using three methods-far-infrared ray, vacuum, and freeze drying and then enzymatically hydrolyzed using nine proteases: Alcalase, Flavourzyme, Kojizyme, Neutrase, Protamex, trypsin, α-chymotrypsin, and papain. In addition, the potential ability of hydrolysates to inhibit lipid accumulation in 3T3-L1 adipocytes was evaluated. The yield of hydrolysates from red sea cucumbers dried using each method was higher than that of the distilled water extract, and protein contents were either similar or higher. The hydrolysates that exhibited inhibitory effects on lipid accumulation, as demonstrated via Oil red O staining, were those obtained by far-infrared ray drying coupled with Alcalase, Flavourzyme, Kojizyme, or Neutrase treatment. In addition to the advantages of far-infrared drying and the characteristics of Flavourzyme, the Flavourzyme hydrolysate of far-infrared-dried red sea cucumber showed the highest inhibitory effect on lipid accumulation. In addition, this hydrolysate significantly decreased the expression of the protein factor fatty acid-binding protein 4, which is related to the late differentiation of 3T3-L1 adipocytes. Taken together, these results suggest that Flavourzyme hydrolysates from farinfrared-dried red sea cucumber may be used as a functional food and/or a pharmaceutical ingredient for the inhibition of lipid accumulation.