• Nuclear Engineering and Technology
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• 제49권4호
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• pp.752-759
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• 2017

The fatigue crack growth behavior of Type 347 (S347) and Type 347N (S347N) stainless steel was evaluated under the operating conditions of a pressurized water reactor (PWR). These two materials showed different fatigue crack growth rates (FCGRs) according to the changes in dissolved oxygen content and frequency. Under the simulated PWR conditions for normal operation, the FCGR of S347N was lower than that of S347 and insensitive to the changes in PWR water conditions. The higher yield strength and better corrosion resistance of the nitrogen-alloyed Type 347 stainless steel might be a main cause of slower FCGR and more stable properties against changes in environmental conditions.

• Steel and Composite Structures
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• 제33권6호
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• pp.777-792
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• 2019

This paper presents a new efficient approach to estimate the S-N type fatigue life assessment curve for S550 high strength steels under low-cycle actions at -60℃. The proposed approach combines a single set of monotonic tension test and one set of fatigue tests to determine the key material damage parameters in the continuum damage mechanics framework. The experimental program in this study examines both the material response under low-cycle actions. The microstructural mechanisms revealed by the Scanning Electron Microscopy (SEM) at the low temperature, furthermore, characterizes the effect due to different strain ratios and low temperature on the low-cycle fatigue life of S550 steels. Anchored on the experimental results, this study validates the S-N curve determined from the proposed approach. The S-N type curve determined from one set of fatigue tests and one set of monotonic tension tests estimates the fatigue life of all specimens under different strain ratios satisfactorily.

• 대한수학회논문집
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• 제22권2호
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• pp.305-313
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• 2007

Let $A_1,\;A_2,\;\ldots,\;A_m$ and $B_1,\;B_2,\;\ldots,\;B_n$ be two sequences of events on the same probability space. Let $X=X_m(A)\;and\;Y=Y_n(B)$, respectively, denote the numbers of those $A_i's\;and\;B_j's$ which occur. We establish new bivariate Bonferroni-type inequalities using consecutive events and deduce a known result.

• 미생물학회지
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• 제28권4호
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• pp.337-344
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• 1990

미국 뉴저지주에 있는 10개의 회전원판 처리장에서 생물막 시료를 채취하여 사상세균에 대해 현미경적 연구를 실시하였다. 활성오니에서 부유형 성장을 하며 흔히 출현하는 Type 1701, Type 0041. Type 021N, Nocardia, Beggiatoa 및 Sphaerotilus가 회전원판체 생물막에서도 출현하였으나 수도(abundance)는 크게 달랐다. 여기서는 Beggiatoa의 출현빈도가 가장 높았으며, Sphaerotilus, Type 0041, Type 1701, Type 021N, Nocardia의 순이었다. 회전원판 생물막에서 발견된 Beggiatoa는 형태적으로 뚜렷히 구별되는 2가지 Type이 존재하였다. 회전원판체의 중심축으로 100cm 깊이에 존재하는 생물막과 외부의 생물막에 존재하는 사상세균의 군집에 대해 인자분서법에 의한 통계처리를 수행한 결과 대부분의 경우, 내부의 군집과 외부의 군집이 통계적으로 유의하게 달랐으며 장소(내부, 외부)와 단(stage) 사이에도 많은 경우 통계적으로 유의한 상호작용이 있었다.

• 대한화학회지
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• 제23권1호
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• pp.1-6
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• 1979

사각형 및 사면체 $[M(II)N_2S_2]$형태 착물의 쌍극자모멘트를 spherical harmonics의 전개방법에 의하여 계산하였다. [M(II) = Co(II), Ni(II), Cu(II) 또는 Zn(II)]. 이들 착물에 대한 쌍극자모멘트의 계산치가 실험치 범위안에 들었다. 계산한 쌍극자모멘트와 자기적 성질을 기초로하여 벤젠용액에서 이들 착물에 대한 가능한 구조를 고찰하였다.

• 동아시아식생활학회지
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• 제19권3호
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• pp.339-349
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• 2009

The purpose of this study was to investigate dietary behavior relative to personality type in young adults, and to offer basic data to apply during nutrition education and counseling. A total of 166 university students performed the MBTI (Mayers-Briggs Type Indicator) test along with questionnaire interviews, and 3 day 24-hr dietary recalls. MBTI personality preferences are presented and separated by 4 types of indices: Extraversion (E) and Introversion (I), Sensing (S) and Intuition (N), Thinking (T) and Feeling (F), and Judgement (J) and Perception (P). More subjects in the I type than the E type had lunch everyday or ate out more than once a week. Compared to the P type, the J type ate a higher proportion of meals with family, and seldom drank alcohol, but a lower proportion had a preference for salty taste. Compared to the N type, the S type had a higher proportion of subjects who consumed large quantities at regular meals as well as when under high amounts of stress. Also, the S type subjects had significantly higher lipid intakes than the N type subjects. Compared to the F type, a higher proportion of the T type subjects ate meals alone but a lower proportion had a dislike for bitter tasting foods. There were no significant differences in total food or energy intakes relative to the different personality types. In conclusion, individual personality type may influence dietary behavior, but additional studies are needed that contain individuals of various ages and include long term dietary surveys.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.901-907
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• 2008

Thermotoga neapolitana $\beta$-glucosidase (BglA) was subjected to site-directed mutagenesis in an effort to increase its ability to synthesize arbutin derivatives by transglycosylation. The transglycosylation reaction of the wild-type enzyme displays major ${\beta}(1,6)$ and minor ${\beta}(1,3)$ or ${\beta}(1,4)$ regioselectivity. The three mutants, N291T, F412S, and N291T/F412S, increased the ratio of transglycosylation/hydrolysis compared with the wild-type enzyme when pNPG and arbutin were used as a substrate and an acceptor, respectively. N291T and N219T/F412S had transglycosylation/hydrolysis ratios about 3- and 8-fold higher, respectively, than that of the wild-type enzyme. This is due to the decreased hydrolytic activity of the mutant rather than increased transglycosylation activity. Interestingly, N291T showed altered regioselectivity, as well as increased transglycosylation products. TLC analysis of the transglycosylation products indicated that N291T retained its ${\beta}(1,3)$ regioselectivity, but lost its ${\beta}(1,4)$ and ${\beta}(1,6)$ regioselectivity. The altered regioselectivity of N291T using two other acceptors, esculin and salicin, was also confirmed by TLC. The major transglycosylation products of the wild type and N291T mutant were clearly different. This result suggests that Asn-291 is highly involved in the catalytic mechanism by controlling the transglycosylation reaction.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.319-320
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• 2009

In this study, high-quality Al-N doped p-type ZnO thin films were deposited on n-type Si (100) wafer or Si coated with buffer layer by DC magnetron sputtering in the mixture of $N_2$ and $O_2$ gas. The target was ceramic ZnO mixed with $Al_2O_3$ (2 wt%). The p-type ZnO thin film showed higher carrier concentration $2.93\times10^{17}cm^{-3}$, lower resistivity of $5.349\;{\Omega}cm$ and mobility of $3.99\;cm^2V^{-1}S^{-1}$, respectively. According to PL spectrum, the Al donor energy level depth ($E_d$) of Al-N codoped p-type ZnO film was reduced to about 51 meV, and the N acceptor energy level depth ($E_a$) was reduced to 63 meV, respectively.

• 대한화장품학회지
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• 제30권4호
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• pp.525-532
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• 2004

본 연구에서는 환경친화적이며 피부자극이 없는 amide type 음이온 계면활성제 N-acyl taurate의 물성을 측정하고 기존의 생분해성이 떨어지고 피부에 자극이 있는 sulfate type 음이온 계면활성제와 비교 평가하여 N-acyl taurate의 기존 음이온 계면활성제와의 대체 가능성을 연구하였다. 또한 물성 측정결과를 바탕으로 샴푸를 제조하고 제형의 안전성과 물성을 평가함으로 써 인체세정제에의 amide type 계면활성제의 적용 가능성을 연구하였다. 실험 결과 N-acyl taurate series는 높은 점도와 낮은 표면장력 및 CMC를 나타내 에멀젼 제조시 작은 입자를 형성하고, 점성을 증가시켜 안정한 에멀젼을 형성하며, 세정 작용시 오염물로의 침투가 용이하고 적은 양의 사용으로 좋은 세정 효과를 얻을 수 있을 것으로 기대되었다. 실제로 N-methyl oleyl taurate를 첨가한 샴푸는 높은 yield point와 일정한 viscosity-curve를 보이고, 작고 균일한 입자를 형성하여 N-acyl taurate가 샴푸 내에서 안정적인 내부구조를 형성하는데 주요 역할을 하며, 이러한 내부구조로 인해 저장안정성을 우수하게 하는 것으로 생각되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.581-584
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• 2003

The austenitic STS 304 stainless steel was turned to clarify the effects of tool geometry on the tool wear. The wear of TiN-TiCN-TiC-TiAlN coated tungsten carbide tool was the smallest, exhibiting larger wear in the order of Si-Al-O-N ceramic, TiN coated tungsten carbide, TiN-TiCN-TiN coated tungsten carbide, TiC-TiN cermet and M20 tungsten carbide tools at the same cutting conditions. The S-type tool of M20 with large approach angle showed the longest tool life of all tools used in this tests due to preventing the groove wear of the side cutting edge. The wear of the S-type tool with the rake angle of 15$^{\circ}$became smaller than with that of -5$^{\circ}$, but the tool with the nose radius of 0.8mm did not perform much better with increasing the rake angle.