• 열처리공학회지
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• 제13권6호
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• pp.383-390
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• 2000

The static creep behaviour of AlSl 420F stainless steel was investigated over the temperature range of $540{\sim}585^{\circ}C$ and the stress range of $13{\sim}19kg/mm^2$ (127.4~186.2MPa). Constant stress creep tests were carried out in the experiment. Measured stress exponent, n, for the creep deformation of the alloy under the given conditions was found to vary at the range of 9.59, 9.15, 8.78, and 8.53 for the temperature of 540, 555, 570, and $585^{\circ}C$ respectively. The activation energy, Qc, for the creep deformation was 106.42, 102.58,97.81, and 94.58 kcal/mole for the stress of 13, 15, 17, and $19kg/mm^2$, respectively. Lason-Miller parameter, P, for the crept specimens for AlSl 420F stainless steel was measured as $P=T(log\;t_T+21)$. The empirical static creep rate obtained by the regression analysis was as follows. $${\varepsilon}={\exp}[(3.79{\times}10^{-2}{\sigma}+2.722)T-3.0747{\sigma}+28.109]{\times}{\sigma}^{(-2.367{\times}10^{-2}T+22.33)}{\exp}\left[-\frac{(-2.015{\sigma}+132.580){\times}10^3}{RT}\right]$$ The failure plane were observed, intergranular fracture was dominated by r (round) type crack over the experimental range.

• 한국강구조학회 논문집
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• 제20권6호
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• pp.731-740
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• 2008

본 연구는 하부 절곡강판과 T형강을 D16mm 스터드 전단연결재를 이용하여 콘크리트와 일체화시킨 교량용 강합성 바닥판의 피로 거동 및 피로성능을 평가하기 위한 것이다. 제안된 강합성 바닥판의 피로성능 평가를 위하여 총 8본의 시험체가 제작되었으며, 각각의 시험체에 3 종류의 일정진폭을 가진 피로하중이 재하되었다. 피로실험결과, 피로균열은 강합성 바닥판 하부 절곡강판의 절곡점에서 발생하여 상부 T형강으로 진전되는 것으로 나타났으며, 피로하중에 따라 시험체의 변위 및 변형률이 증가하고 피로균열발생 후 변위와 변형률이 급격히 변화하였다. 제안된 강합성 바닥판의 피로강도는 도로교설계기준 및 도로교설계기준 피로상세 범주의 자료가 된 NCHRP 102와 NCHRP 147 보고서의 피로실험결 과와 비교하여 평가한 결과 대상 강합성 바닥판은 피로상세 범주 C에 해당하는 것으로 평가되었다.

• Journal of Gastric Cancer
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• 제19권1호
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• pp.102-110
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• 2019

Purpose: Despite an increased acceptance of laparoscopic gastrectomy (LG) in early gastric cancer (EGC), there is insufficient evidence for its oncological safety in advanced gastric cancer (AGC). This is a prospective phase II clinical trial to evaluate the feasibility of LG with D2 lymph node dissection (LND) in AGC. Materials and Methods: The primary endpoint was set as 3-year disease-free survival (DFS). The eligibility criteria were as follows: 20-80 years of age, cT2N0-cT4aN3, American Society of Anesthesiologists score of 3 or less, and no other malignancy. Patients were enrolled in this single-arm study between November 2008 and May 2012. Exclusion criteria included cT4b or M1, or having final pathologic results as EGC. All patients underwent D2 lymphadenectomy. Three-year DFS rates were estimated by the Kaplan-Meier method. Results: A total of 157 patients were enrolled. The overall local complication rate was 10.2%. Conversion to open surgery occurred in 11 patients (7.0%). The mean follow-up period was $55.0{\pm}20.4months$ (1-81 months). The cumulative 3-year DFS rates were 76.3% for all stages, and 100%, 89.3%, 100%, 88.0%, 71.4%, and 35.3% for stage IB, IIA, IIB, IIIA, IIIB, and IIIC, respectively. Recurrence was observed in 37 patients (23.6%), including hematogenous (n=6), peritoneal (n=13), locoregional (n=1), distant node (n=8), and mixed recurrence (n=9). Conclusions: In addition to being technically feasible for treatment of AGC in terms of morbidity, LG with D2 LND for locally advanced gastric cancer showed acceptable 3-year DFS outcomes.

• 무역상무연구
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• 제41권
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• pp.79-102
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• 2009

L/C transaction, the most important issue for the seller and the buyer is the theory of documentary transaction and the theory of strict compliance which are the principles of L/C transactions. According to the leading cases in England and America where the practice of L/C transactions was created and developed, the descriptions of the commodities specified on all the documents which are submitted based on an L/C, should be identical to the descriptions of commodities specified in the L/C. And further, many leading cases of L/C continuously repeat to emphasize strict compliance. However, the recent leading cases in and out of the country show that the principle of strict compliance is being weakened. The leading cases in America show two trends of weakening the principle of strict compliance. That is, on the contrary to strict compliance, tends to apply substantial compliance (which puts more value on the substance of the documents). These leading cases reflect the attitudes of the judicial and the legislative authorization that don't want to approve formal approach to the commercial law. Recently, the Supreme Court of Korea is giving a decision on the principle of strict compliance, "The documents attached to an L/C should strictly comply with the conditions in the L/C, but it doesn't mean that they should be perfectly identical without any mistake in words. In case the bank can understand through reasonable care that a small mistake in words is too trivial to give different meaning or to give damage to the conditions of the L/C, the documents are regarded to comply with the conditions of the L/C. However, the judgment should be based on whether the difference between the documents and the L/C can be admitted by the international standard bank transaction practice or not." This decision tells that the principle of strict compliance is quite much modified so application of this modification can't be ignored. However, from the viewpoint of the party who requests to open an L/C, there is a criticism that a bank's arbitrary judgement can be involved. Therefore, reviewing the original purpose of L/C transactions (activating international transactions), the principle of strict compliance may be thought old-fashioned because it emphasizes a form, but in reality, for prompt transaction and payment, the principle of strict compliance should be observed in L/C transactions. And further, if a legislative device is prepared to systematically compensate for several side-effects, the principle of strict compliance will improve dynamic flow of prompt and low-costly L/C transactions. On the other hand, it will be able to protect the interested parties.

• Journal of Korean Neurosurgical Society
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• 제53권2호
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• pp.89-95
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• 2013

Objective : Similar to back pain, neck pain has recently shown to have increasing prevalence. Magnetic resonance imaging (MRI) is useful in identifying the causes of neck pain. However, MRI shows not only pathological lesions but also physiological changes at the same time, and there are few Korean data. The authors have attempted to analyze the prevalence of disc degeneration in highly selective asymptomatic Korean subjects using MRI. Methods : We performed 3 T MRI sagittal scans from C2 to T1 on 102 asymptomatic subjects (50 men and 52 women) who visited our hospital between the ages of 14 and 82 years (mean age 46.3 years). All images were read independently by three observers (two neurosurgeons and one neuroradiologist) who were not given any information about the subjects. We classified grading for cervical disc herniation (HN), annular fissure (AF), and nucleus degeneration (ND), using disc degeneration classification. Results : The prevalence of HN, AF, and ND were 81.0%, 85.9%, and 95.4%, respectively. High prevalence of HN, AF, and ND was shown compared to previous literature. Conclusion : In asymptomatic Korean subjects, the abnormal findings of 3 T MRI showed a high prevalence in HN, AF, and ND. Several factors might play important roles in these results, such as population-specific characters, MRI field strength, and disc degeneration grading system.

• Journal of Magnetics
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• 제8권2호
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• pp.98-102
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• 2003

Microstructure and magnetic transport phenomina in rf sputtered AIN/CO type ten- layered discontinuous films of nanoscaled [AIN(3 nm)/Co(t nm)]…$_10$ with t$_Co$=1.0∼2.0 nm have been investigated. The microstructure and tunneling magnetic resistance of the samples are strongly dependent on the thickness of Co layer, Negative tunneling magneto-resistance due to the spin-dependent transport has been observed along the current-in-plane configuration in the samples having the Co layers below 1.6 nm thick. When the thickness of Co layer was less than 1.2 nm, randomly oriented granular Co particles were completely isolated and embedded in amorphous AIN matrix, and the films showed the superparamagnetic behavior with a high MR value of ${\Delta}p/p_0$=1.8%. As t$_Co$ increases, a transition from the regime of co-existence of superparamagnetic and ferromagnetic behaviors to ferromagnetic behavior was observed. funneling barrier called “decay length far tunneling” fur the films haying the thickness of Co layer from 1.4 to 1.6 nm was measured to be ranged from 0.004 to 0.021 ${\AA}$$^{-1}$.

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.311-317
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• 1999

Human T-cell leukemia virus Type-I (HTLV-I) is etiologically associated with rare adult T-cell leukemia, a malignant T-cell disorder. cDNAs encoding p24 (gag), gp21(env), and pXII of HTLV-I were amplified by polymerase chain reaction (PCR) using the genomic DNA extracted from HUT102 cell line as a template. The amplified cDNAs were cloned into the Escherichia coli expression vectors and over-expression of the recombinant proteins were achieved by adding IPTG into the culture media in order to induce the promoter. The molecular weights of the recombinant p24, gp21, and pXII, determined by SDS-PAGE, were found to be approximately 28 kDa, 23 kDa, and 15 kDa, respectively. Reactivity of the recombinant proteins with human sera was tested by the immunoblot assay. The gp21 and p24 reacted against the sera obtained from HTLV-I-infected individuals but not against the sera obtained from normal persons. These results suggest that the recombinant proteins expressed in E. coli were recognized by antibodies in sera from HTLV-I infected patients. These recombinant proteins would be applicable for detecting the presence of antibodies against HTLV-I in human blood samples.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권3호
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• pp.106-112
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• 2003

A combined discharge type ozonizer was designed and manufactured. The increase or decrease of temperature greatly influences the characteristics of ozone concentration ( $O_{3con}$), ozone generation ( $O_{3g}$) and ozone yield ( $O_{3Y}$) of a discharge type ozonizer. The characteristics of ozone concentration, ozone generation and ozone yield rate were investigated by varying the gas flow rate (Q), the discharge power ( $W_{d}$) and the temperature (T). At T=25[$^{\circ}C$] the values of $O_{3con}$ were found as 5632, 4200, 2500 and l800[ppm] at Q = 1, 2, 4 and 6[l/min] respectively. At the same temperature the corresponding values of $O_{3g}$ were found as 662, 988, 1176 and l270[mg/h] and those of $O_{3Y}$ were found as 67, 102, 119 and 135[g/kWh] respectively. When the temperature is decreased to -50[$^{\circ}C$], the values of $O_{3con}$ were found as 9000, 6700, 4000 and 2800[ppm] respectively at Q = 1, 2, 4 and 6[l/min]. At the same value of temperature the corresponding values of $O_{3g}$ were found as 1220, 1576, 1882 and 2050[mg/h] and those of $O_{3Y}$ were found as 120, 159, 188 and 202[g/kWh] respectively. Hence as the temperature was decreased from 25 to -50[$^{\circ}C$], the efficiencies of ozone generation were increased by 79, 55, 58 and 49[%] respectively at Q = 1, 2, 4 and 6[l/min].]. 6[l/min].].

• 한국세라믹학회지
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• 제32권6호
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• pp.659-668
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• 1995

Zirconium carbide was prepared from the mixture of metal zirconium and carbon powders in argon atmosphere by Self-propagating High-temperature Synthesis (SHS) in order to obtain the best carbon source and dilution contents. The most exellent result was obtained in the case that active carbon was added as a starting material, 20~30 wt% dilution content. From thermal profile analysis an apparent activation energy of 118 KJ/mol was calculated. The maximum heating rate achieved during 15 wt% ZrC reaction by product dilution method was approximately 1.54$\times$105 K/s. Coupling this value with the measured wave velocity of 1.026cm/s yielded a maximum thermal gradient fo $1.5\times$105 K/cm. Using the definition of t* and the measured wave velocity, the effective thermal diffusivity, $\alpha$, was calculated to be 0.62$\times$102 $\textrm{cm}^2$/s.

• 대한핵의학회지
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• 제19권1호
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• pp.95-102
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• 1985

The activation of adenylate cyclase of human thyrocytes in primary cell culture and the release of c-AMP into the medium are used to detect b-TSH and TSAb in sera of patients with autoimmune thyroid disease. Sera of patients are used directly as a part of cell culture without immunoglobulin precipitation. In the above TSI bioassay, TSAb pooled serum show c-AMP concentration between that of 1mU/ml and 10 mU/ml b-TSH but normal control pooled serum doesn't show any detectable c-AMP response. Ninety fiye percent of untreated Graves' patients shows TSAb activity above normal range, 20% of Hashimoto's and 36% of euthyroid Graves' patients show detectable TSAb activity.