• 한국산학기술학회논문지
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• 제15권6호
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• pp.4002-4006
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• 2014

자동차 배출가스는 자동차에 의해 발생되는 일산화탄소, 탄화수소, 납 외에 사람의 건강 또는 생활 환경에 피해를 일으킬 염려가 있는 물질을 말한다. 배출가스를 감소시키기 위해서 다양한 기술을 개발하는 것도 중요하지만 현재 사용되어 지고 있는 요소를 분석하여 최적의 상태를 찾는 것도 중요한 사항이라 여겨진다. 본 연구는 냉각수에 함유되는 부동액이 배출가스에 영향을 미칠 수 있음에 착안하여 현재 국내에서 시판되고 있는 5개 회사제품의 부동액을 권고 수준의 양을 냉각수에 함유시켜 HC, NOx, $CO_2$ 배출량을 측정하고 배출가스에 미치는 영향을 파악하고자 하였다. 또한, 5개회사 부동액 제품에 대하여 냉각팬 구동시간과 NOx 배출량과의 상관관계를 살펴보고자 하였다. 엔진오일의 온도는 자동차 검사 규격에 맞도록 $90{\sim}93^{\circ}C$에 맞추었고, 수동기어를 사용하는 소형승용차의 검사 규격 속도 $40{\pm}2Km/h$에서 수행하였다. 실험결과 D사 부동액이 팬 작동시간이 가장 짧고, $CO_2$, NOx 배출량이 가장 적게 나타났다.

• Clinical and Experimental Reproductive Medicine
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• 제44권1호
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• pp.8-14
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• 2017

Objective: The aim of this study was to analyze the effect of supplementing vitrification and warming solutions with two types of antifreeze proteins (AFPs) and the combination thereof on the follicular integrity of vitrified-warmed mouse ovaries. Methods: Ovaries (n=154) were obtained from 5-week-old BDF1 female mice (n=77) and vitrified using ethylene glycol and dimethyl sulfoxide with the supplementation of 10 mg/mL of Flavobacterium frigoris ice-binding protein (FfIBP), 10 mg/mL of type III AFP, or the combination thereof. Ovarian sections were examined by light microscopy after hematoxylin and eosin staining, and follicular intactness was assessed as a whole and according to the type of follicle. Apoptosis within the follicles as a whole was detected by a terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling assay. Results: The proportion of overall intact follicles was significantly higher in the type III AFP-supplemented group (60.5%) and the combination group (62.9%) than in the non-supplemented controls (43.8%, p<0.05 for each). The proportion of intact primordial follicles was significantly higher in the FfIBP-supplemented (90.0%), type III AFP-supplemented (92.3%), and combination (89.7%) groups than in the non-supplemented control group (46.2%, p<0.05 for each). The proportions of non-apoptotic follicles were similar across the four groups. Conclusion: Supplementation of the vitrification and warming solutions with FfIBP, type III AFP, or the combination thereof was equally beneficial for the preservation of primordial follicles in vitrified mouse ovaries.

• BMB Reports
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• 제41권1호
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• pp.72-78
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• 2008

Human NeuNAc-9-P synthase is a two-domain protein with ability to synthesize both NeuNAc-9-P and KDN-9-P. Its mouse counterpart differs by only 20 out of 359 amino acids but does not produce KDN-9-P. By replacing the AFL domain of the human NeuNAc-9-P synthase which accommodates 12 of these differences, with the mouse AFL domain we examined its importance for the secondary KDN-9-P synthetic activity. The chimeric protein retained almost half of the ability of the human enzyme for KDN-9-P synthesis while the NeuNAc-9-P production was reduced to less than 10%. Data from the homology modeling and the effect of divalent ions and temperature on the enzyme activities suggest conformational differences between the human and mouse AFL domains that alter the shape of the cavity accommodating the substrates. Therefore, although the AFL domain itself does not define the ability of the human enzyme for KDN-9-P synthesis, it is important for both activities by aiding optimal positioning of the substrates.

• 한국기계가공학회지
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• 제16권4호
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• pp.76-82
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• 2017

The cylinder liner of a diesel engine is commonly made of gray cast iron. However, this cylinder liner can be damaged by the cavitation phenomenon in wet conditions. This cavitation has remained an unsolved problem until now. In this study, the cause of cavitation corrosion due to antifreeze solution was examined using a scanning electron microscope (SEM) and a 3D microscope. The necessary data to prevent the damage caused by cavitation erosion and the corrosion of gray cast iron cylinder liner was obtained. Analysis determined that the gray iron structure consists of an ${\alpha}-matrix$, flake graphite, and steadite. Cavitation erosion was initiated in the coarse flake graphite and propagated into the steadite with pitting. Under repetitive reaction conditions, the ${\alpha}-matrix$ was partially separated from the gray cast iron. This study is expected to be used as the basic data for the prevention of gray cast iron cavitation erosion and corrosion by controlling the graphite and steadite phases.

• 한국자기공명학회논문지
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• 제26권4호
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• pp.46-50
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• 2022

Antifreeze proteins (AFPs) bind to the ice crystals and then are able to inhibit the freezing of body fluid at subzero temperatures. Type III AFPs are categorized into three subgroups, QAE1, QAE2, and SP isoforms, based on differences in their isoelectric points. We prepared the QAE2 (AFP11) and SP (AFP6) isoforms of the notched-fin eelpout AFP and their mutant constructs and determined their temperature gradients of amide proton chemical shifts (𝚫δ/𝚫T) using NMR. The nfeAFP11 (QAE2) has the distinct 𝚫δ/𝚫T pattern of the first 3₁₀ helix compared to the QAE1 isoforms. The nfeAFP6 (SP) has the deviated 𝚫δ/𝚫T values of many residues, indicating its backbone conformational distortion. The study suggests the distortion in the H-bonding interactions and backbone conformation that is important for TH activities.

• 한국산학기술학회논문지
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• 제21권2호
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• pp.619-626
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• 2020

환경 보호까지 고려한 Non-amine계 부식 방지제를 포함하는 새로운 부동액 개발이 주요한 이슈가 되고 있다. 본 연구에서는 Non-amine계 부식 방지제 4종을 합성하고 이를 이용하여 새로운 자동차용 부동액 5종을 제조하여 무게 변화량, 표면 관찰, 거칠기 측정, 용액 중 구리 용출량 측정을 통해 구리의 부식 속도를 평가하였다. 평가 결과 부동액 5종중에서 Sample 4가 유도결합 플라즈마 광도계로 측정하였을 때 구리의 용출량이 적고 용출 속도가 매우 느렸다. Sample 4는 시험 후 금속 표면이 매끄러운 편이나 표면에 작은 국부 부식이 관찰됨에 따라 표면에 부식 생성물 층을 고르게 형성한 것으로 보여 구리의 부동태화에 따른 부식 억제 효과가 있으므로 가장 양호한 부식방지 성능을 보였다. Sample 4에 첨가된 주요 부식방지제는 1-Aminomethyl(N',N'-di(2-hydroxyethyl) benzotrazole로, 이 부식 억제 성분은 국부부식은 상대적으로 높으나 부동태화가 진행된 Sample 5에도 일정 함량 포함되었다. 따라서 본 연구에서 사용한 4종의 부식 방지제 중 1-Aminomethyl(N',N'-di(2-hydroxyethyl)benzotrazole이 가장 부식 억제 효과가 높았다. 이는 상기의 부식 방지제가 부동액상에서 구리의 부동태화를 촉진함으로써 부식을 방지하는 것으로 판단된다.

• 오토저널
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• 제16권6호
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• pp.1-8
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• 1994

• 한국동물학회:뉴스레터
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• 제12권2호
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• pp.107.1-107
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• 1995

No Abstract, See Full Text

• 한국동물학회:학술대회논문집
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• 한국동물학회 1995년도 한국생물과학협회 학술발표대회
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• pp.243.1-243
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• 1995

No Abstract, See Full Text

• 식품기술
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• 제23권3호
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• pp.376-384
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• 2010