• 한국전기전자재료학회논문지
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• 제29권1호
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• pp.17-22
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• 2016

The activation energy of a material is an important factor that significantly affects the lifetime and can be used to develop a degradation model. In this study, a thermal analysis was carried out to evaluate and collect quantitative data on the degradation of insulation materials like EPR and CSP used for nuclear power plant cables. The activation energy was determined from the relationship between log ${\beta}$ and 1/T based on the Flynn.Wall.Ozawa method, by a TGA test. The activation energy was also derived from the relationship between ln(t) and 1/T based on isothermal analysis, by an OIT test. The activation energy of EPR derived from thermal analysis was used to calculate the accelerated aging time corresponding to the number of years of use, employing the Arrhenius equation, and determine the elongation corresponding to the accelerated aging time.

• Environmental Engineering Research
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• 제24권1호
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• pp.137-143
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• 2019

In this study, extraction, clean-up and instrumental analytical conditions were optimized for identifying and quantifying methyl-, chloromethylbenzi-, octyl- isothiazolinone (MIT, CMIT, BIT, OIT) and 3-iodo-2-propynyl butyl carbamate (IPBC), widely used biocidal active ingredients in human hygiene consumer products. Accuracy of the developed ultrasonic assisted extraction method followed by HPLC/MS analysis for four isothiazolinones and IPBC ranged between 60.4% and 113% in various types of consumer product samples. Method detection limits ranged 0.011-0.034 mg/kg for wet wipes, 0.57-1.5 mg/kg for liquid detergent and 0.58-1.6 mg/kg for powder detergent. Wet wipes, powder and liquid detergents collected from local market in Korea were analyzed to demonstrate the applicability of the developed method. Even after the regulation of those compounds in wet wipes, CMIT, MIT and IPBC were still frequently detected from complementary wet wipes without brand labels which were distributed to customers at local retail shops and restaurants. The maximum observed concentrations of MIT and CMIT found in those complementary wet wipes were 70.2 mg/kg and 11.3 mg/kg, respectively.

• 미생물학회지
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• 제30권3호
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• pp.225-231
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• 1992

생물체내의 ascorbic acid :dehydroascorbic acid system 을 조절하는데 관여하는 것으로 알려진 ascorbate 산화효소의 활성을 단세포 녹조류인 Chlamydomonas reinhardtii 에서 확인함으로써 이 효소의 존재와 특성을 고찰하였다. 조효소는 native gel 전기 영동에 의한 활성 염색과 분광광도계에 의한 ascorbic acid .의 흡광도 감소 측정에서 뚜렷한 활성을 나타내었다. 황산암모늄 침전, hydroxyapatite 흡착 크로마토그래피, 그리고 Sephadex G-150 gel 여과 크로마토그래피 분리한 결과 26.1 units/mg /의 specific activity 를 나타내었다. 분리된 ascorbate 산화효소는 $55^{\circ}C$, pH 4.6 에서 가장 활성도가 높았다. Native gel 전기 영동에서 88,000 dalton 갸량의 분자량을 가지고 있었고 소단위체의 분자량을 55,000 이었다. 또한 Western bloting technique 을 이용하여 C. reinhardtii 의 ascorbate oxidase를 확인하였다.

• Animal Bioscience
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• 제36권2호
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• pp.191-199
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• 2023

Objective: This study aimed to investigate the significant single nucleotide polymorphisms (SNPs) and genes associated with nine reproduction and morphological traits in three breed populations of Chinese goats. Methods: The genome-wide association of nine reproduction and morphological traits (litter size, nipple number, wattle, skin color, coat color, black dorsal line, beard, beard length, and hind leg hair) were analyzed in three Chinese native goat breeds (n = 336) using an Illumina Goat SNP50 Beadchip. Results: A total of 17 genome-wide or chromosome-wide significant SNPs associated with one reproduction trait (litter size) and six morphological traits (wattle, coat color, black dorsal line, beard, beard length, and hind leg hair) were identified in three Chinese native goat breeds, and the candidate genes were annotated. The significant SNPs and corresponding putative candidate genes for each trait are as follows: two SNPs located on chromosomes 6 (CSN3) and 24 (TCF4) for litter size trait; two SNPs located on chromosome 9 (KATNA1) and 1 (UBASH3A) for wattle trait; three SNPs located on chromosome 26 (SORCS3), 24 (DYM), and 20 (PDE4D) for coat color trait; two SNPs located on chromosome 18 (TCF25) and 15 (CLMP) for black dorsal line trait; four SNPs located on chromosome 8, 2 (PAX3), 5 (PIK3C2G), and 28 (PLA2G12B and OIT3) for beard trait; one SNP located on chromosome 18 (KCNG4) for beard length trait; three SNPs located on chromosome 17 (GLRB and GRIA2), 28 (PGBD5), and 4 for hind leg hair trait. In contrast, there were no SNPs identified for nipple number and skin color. Conclusion: The significant SNPs or genes identified in this study provided novel insights into the genetic mechanism underlying important reproduction and morphological traits of three local goat breeds in Southern China as well as further potential applications for breeding goats.

• 폴리머
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• 제33권5호
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• pp.446-451
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• 2009

신뢰성 평가 시험법인 RS M 0042에 따라, 열화시간 경과에 따른 선형저밀도 폴리에틸렌 파이프의 신뢰성 평가를 수행하였다. 열화시간이 증가함에 따라, 인장강도는 250일 열화시점까지 비례적으로 증가하였고, 경도는 비교적 미소한 증가를 보였으며, 연신율은 점진적으로 감소하는 경향을 보였다. 이러한 결과는 열화시간이 증가함에 따른, 결정화도의 증가와 열산화에 의한 가교밀도의 증가, 사슬 전단 및 사슬 운동성의 감소 등에 기인한 것으로 판단된다. 장기정수압시험 결과는 초기의 연성파괴에서 차후 취성파괴로 전환되는 시점이 존재함을 확인하였다. 산화유도시간 측정은 선형저밀도폴리에틸렌 파이프의 열산화 정도를 관찰하기 위해 도입되었다. 측정 결과는 250일 이후 선형저밀도폴리에틸렌 파이프에 첨가된 산화방지제가 거의 고갈되었음을 보여준다. $100^{\circ}C$ 열화 조건에서 산화방지제의 잔존량을 계산할 수 있는 실험식을 열화시간의 함수로 표현하여 제안하였다. 적외선분광분석 결과는 열화된 선형저밀도폴리에틸렌 파이프 표면상에 카르보닐 및 하드록실 관능기가 증가하였음을 보여준다. 이는 선형저밀도폴리에틸렌 표면의 탄화수소 그룹의 산화가 국부적으로 발생하였음을 나타낸다.