• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3524-3526
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• 2011

• 대한기계학회논문집A
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• 제26권5호
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• pp.896-903
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• 2002

The susceptibility of SCC for the weldment and PWHT specimens of HT-60 steel was evaluated using a slow strain rate method under applied potential by means of the potentiostat in synthetic seawater. In case of the parent, anodic polarization voltage was inappropriate in elongating the time to failure(TTF). -0.8V corresponding to cathodic protection range is most effective in improving the SCC resistance against corrosive environment. In case of the weldment, the values of reduction of area(ROA) and TTF at -0.68V corresponding to cathodic polarization value were 45.2% and 715,809sec which were the largest and longest life among other applied potentials. Those were vise versa at -1.1V. In case of the PWHT specimens, TTF and ROA at -0.68V was longest and largest like the weldment. Besides, PWHT is effective in prolonging the time to failure of the welded off-shore structure due to softening of effect. Regardless of the weldment and PWHT specimen, as corrosion rate gets higher, TTF becomes shorter and deformation behaviour for the weldment and PWHT specimen at -1.1V was shown to be irregular. Finally, it was found that specimens showed brittle fracture at -1.1V, but more ductile fracture accompanying the micro-cracks at applied potential of -0.68V.

• Journal of Chest Surgery
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• 제53권5호
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• pp.297-300
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• 2020

Background: This study aimed to assess the effect of vessel size and flow characteristics on the maturation of autogenous radiocephalic arteriovenous fistulae (RCAVFs). Methods: We retrospectively reviewed records of patients undergoing RCAVF creation at a single medical center from January 2013 to December 2019. Operative variables were compared between patients whose fistulae matured and those whose fistulae failed to mature. Results: Overall, 152 patients (33 of whom were women) with a mean age of 62.6±13.6 years underwent RCAVF creation; functional maturation was achieved in 123. No statistically significant differences were observed between patients in whom maturation was or was not achieved in terms of the following variables: female sex (20.3% vs. 25.0%), radial artery size (2.5 vs. 2.4 mm), and pulsatility index (0.69 vs. 0.62). Low intraoperative transit time flowmetry (TTF; 150.4 vs. 98.1 mL/min) and small vein size (2.4 vs. 2.0 mm) were associated with failure of maturation. The best cutoff diameter for RCAVF TTF and cephalic vein size were 105 mL/min and 2.45 mm, respectively. Conclusion: In patients who undergo RCAVF creation, vein diameter on preoperative ultrasonography and intraoperative TTF are predictors of functional maturation. We identified an intraoperative TTF cutoff value that can be used for intraoperative decision-making.

• 한국진공학회지
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• 제5권3호
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• pp.229-238
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• 1996

The electromigration phenomena and the characterizations of the conductor lifetime (Time-To-Failure, TTF) in Al-1%Si thin film interconnections under D.C. and Pulsed D.C. conditions were investigated . Meander type test patterns were fabricated with the dimensions of 21080$mu \textrm{m}$ length, 3$\mu\textrm{m}$ width, 0.7$\mu\textrm{m}$ thickness and the 0.1$\mu\textrm{m}$/0.8$\mu\textrm{m}$($SiO_2$/PSG)dielectric overlayer. The current densities of $2 \times10^6 A/\textrm{cm}^2$ and $1 \times10^7 A/\textrm{cm}^2$ were stressed in Al-1%Si thin film interconnection s under a D.C. condition. The peak current densities of $2 \times10^6 A/\textrm{cm}^2$ and $1 \times10^7 A/\textrm{cm}^2$ were also applied under a Pulsed D.C. condition at frequencies of 200KHz, 800KHz, 1MHz, and 4MHz with the duty factor of 0.5. THe time-to-failure under a Pulsed D.C.($TTF_{pulsed D.C}$) was appeared to be larger than that under a D.C. condition. It was found that the TTF under both a D.C. and a Pulsed D.C. condition. It was found that the TTF under both a D.C. and a Pulsed D.C. condition largely depends upon the appiled current densities respectively . This can be explained by a relaxation mechanism view due to a duty cycle under a Pulsed D.C. related to the wave on off. The relaxation phenomena during the pulsed off period result in the decayof excess vacancies generated in the Al-1%Si thin film interconnections because of the electrical and mechanical stress gradient . Hillocks and voids formed by an electromigration were observed by using a SEM (Scanning Electron Microscopy).

• 패션비즈니스
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• 제16권4호
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• pp.46-63
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• 2012

This research purposed to the conceptual model with integrates the expanded task technology fit theory(TTF) and technical acceptance model(TAM) for the effect of the motivational factor of the consumer characteristics in the used the fashion mobile commerce. To fulfill the study objectives, a total of 432 questionnaires were conducted to the customers with first-hand experience with merchandise in mobile commerce. The judgement sampling method was employed on sample population ages from 20s to 30s over two month period. Based on the results of the above-mentioned path analysis, The result showed that First, the utilization experience was adopted as the have the notes effect in the and information acquisition fit, support fit, quality fit, perceived ease of use. and the innovativeness was adopted as the have the notes effect in the information support fit, perceived trust, perceived ease of use. and the self-efficacy was adopted as the have the notes effect in the and information quality fit, perceived usefulness, perceived ease of use. Second, the information acquisition fit, support fit were adopted as the have the notes effect in the perceived trust, perceived usefulness, perceived ease of use. and the information quality fit was adopted as the have the notes effect in the perceived trust, perceived usefulness. Third, the appeared similar effect which considers from all relationships such as perceived trust, perceived usefulness, perceived ease of use, acceptance attitude and purchase intention.

• 대한화학회지
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• 제44권6호
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• pp.513-517
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• 2000

TTF (tetrathiafulvalene) 유도체의 전구체로서 5,6-dimethyl-1,3-dithiolo[4,5-b][1,4]dithiin-2-thione (화합물 3)을 로손반응에 의하여 합성하였다. 치환기의 종류에 따라 1,4-dithiin이나 티오펜이 포함된 두 가지의 서로 다른 생성물이 얻어졌고, 이들은 $^{13}C$ NMR과 고 분해능 전자충돌(HREI) 질량분석 분광학으로 특성화하였다. 화합물 3의 합성은 X-선 구조분석으로도 확인되었다. 결정학적 자료: 삼사정계, 공간군 P1, a=4.145(2)${\AA}$, b=10.600(2)${\AA}$, c=12.279(2)${\AA}$, ${\alpha}=71.440(10)^{\circ},\;{\beta}=84.30(2)^{\circ},\;{\gamma}=87.31(2)^{\circ}$, Z=2, $R(wR_2$)=0.0559(0.1416). 두 가지 생성물의 생성 기구를 비교하여 설명하였다.

• Journal of Genetic Medicine
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• 제7권1호
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• pp.9-15
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• 2010

선천성 갑상샘 기능 저하증은 신생아 3,000명 내지 4,000명당 한 명꼴로 발생하며 선천성 내분비 질환 중 가장 흔한 것으로 알려져 있다. 본 질환은 갑상샘 발달 과정의 결함으로 인한 갑상샘 형성 부전 또는 호르몬 합성 장애로 인해 가장 흔히 발생한다. 이는 대부분 산발성으로 발생하나 갑상샘 형성 부전의 2%정도에서 가족성으로 발생하기도 하며 유기화 결함에 의한 갑상샘 기능 저하증은 열성으로 유전된다. 본 질환과 관련된 후보 유전자들은 갑상샘 형성 부전 군과 갑상샘 호르몬 합성 장애 군 등 크게 두 군으로 나뉜다. 갑상샘 형성 부전과 관련된 유전자는 비증후군성에 속하는 것으로 TSHR 유전자가 있고 여러 다른 복합적 기형을 동반한 증후군성에 속하는 것으로 Gsa 유전자 및 갑상샘 전사 인자 유전자(TTF-1, TTF-2, Pax-8) 등이 있다. 호르몬 합성장애와 관련된 것으로 TPO와 TG 유전자가 언급되었고 근래 PDS, NIS와 THOX2 유전자가 소개되었다. 또한 iodothyronine 이동 결함과 관련되어 심각한 신경학적 후유증을 동반할 수 있는 갑상샘 기능 저하증에 대한 유전적 근거가 제시되었다.

• 한국환경보건학회지
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• 제37권6호
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• pp.467-473
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• 2011

Objectives: Wastewater treatment plants typically produce a large volume of waste sludge. In this study, the conditioning and dewatering properties of a digested and thickened sludge from an industrial wastewater treatment plant were investigated in order to improve the dewaterbility of the sludge. Methods: Jar-tests and Buchner funnel tests were carried out to assess the conditioning and dewatering properties of a waste sludge. TTF (Time to Filter Test) and SRF (Specific Resistance to Filtration) were adopted as the indices of sludge dewaterbility. Results: The valuation indices influencing the dewaterbility of the waste sludge, including TTF, SRF, water contents, VS/TS ratio and turbidity, were measured. The TTF and SRF of the digested and thickened sludge were decreased to 40 sec, $3.43{\times}10^{12}$ m/kg, and 39 sec, $1.09{\times}10^{12}$ m/kg, respectively. Conclusions: The conditioner composed of natural inorganic materials turned out to be effective in the reduction of sludge water contents.

• 유통과학연구
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• 제15권11호
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• pp.5-19
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• 2017

Purpose - According to the research findings, it proposes corresponding market promotion schemes, for Alipay, WeChat wallet and even other payment service providers and mobile internet companies to understand the factors which promote or hinder users' acceptance of mobile payment. Research design, data, and methodology - Statistic analysis of data and social science statistical software of IBM Statistics 23.0 and IBM SPSS AMOS 23.0 were adopted for all the data researched. Results - The technical features of the third party mobile payment and the task characteristics of users have positive influence on the matching degree between task and technology, and the matching degree between task and technology of the third party mobile payment has positive influence on the performance expectancy, effort expectancy and usage intention. The social influence, facilitating condition, price value and enjoyment motivation have significant and positive influence on users' intention of mobile payment adoption. The perceive security of the mobile fingerprint payment of users has positive influence on users' intention of usage. Conclusions - This research has the main contribution on the analysis on the key factors with influence on the third party mobile payment usage by utilizing the integrated model of UTAUT2 and TTF.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.179-179
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• 2011

관통전극(TSV, Trough Silicon Via) 기술은 전자부품의 소형화, 고성능화, 생산성 향상을 이룰 수 있는 기술이다. Cu는 현재 배선 기술에 적용되고 있고 전기적 저항이 낮아서 TSV filling 재료로 사용된다. 하지만 확산 방지막에 의해 완벽히 감싸지지 않는다면, Cu+은 빠르게 절연막을 통과하여 Si 웨이퍼로 확산된다. 이런 현상은 절연막의 누설과 소자의 오동작 등의 신뢰성 문제를 일으킬 수 있다. 현재 TSV의 제조와 열 및 기계적 응력에 관한 연구는 활발히 진행되고 있으나 Biased-Thermal Stress(BTS) 조건하의 Cu 확산에 관한 연구는 활발하지 않는 것이 실정이다. 이를 위해 본 연구에서는 TSV용 Cu 확산 방지막 Ti에 대해 Cu+의 drift 억제 특성을 조사하였다. 실험을 위해 Cu/확산 방지막/Thermal oxide/n-type Si의 평판 구조를 제작하였고 확산 방지막의 두께에 따른 영향을 조사하기 위해 Ti의 두께를 10 nm에서 100 nm까지 변화하였으며 기존 Cu 배선 공정에서 사용되는 확산 방지막 Ta와 비교하였다. 그리고 Cu+의 drift 측정을 위해 Biased-Thermal Stress 조건(Thermal stress: $275^{\circ}C$, Bias stress: +2MV/cm)에서 Capacitance 및 Timedependent dielectric breakdown(TDDB)를 측정하였다. 그 결과 Time-To Failure(TTF)를 이용하여 Cu+의 drift를 측정할 수 있었으며, 확산 방지막의 두께가 증가할수록 TTF가 증가하였고 물질에 따라 TTF가 변화하였다. 따라서 평판 구조를 이용한 본 실험의 Cu+의 drift 측정 방법은 향후 TSV 구조에서도 적용 가능한 방법으로 생각된다.