Modified Microstructure Selection Map and Growth Conditions of the Band Structure in Directionally Solidified Hypo-Peritectic Alloys

Jong‑Ho Shin,Jehyun Lee 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

Considering the variation of the solid/liquid interface morphology with a growth condition, microstructure selection map inperitectic system was modified by comparing growing α (primary phase) interface tip temperature and β (peritectic phase)nucleation temperature. The results were proved experimentally in hypo-peritectic Sn–Cd alloys by delicate directionalsolidification experiment under the diffusive growth condition using capillary thin tube. When β-phase took over α-phaseand grew a short distance as the leading phase, the instability of β-phase was first observed experimentally. This phenomenawas explained by constitutional undercooling, which was present temporarily in liquid ahead of the β/l interface.

Effects of Test Temperature on Low Cycle Fatigue Behaviors in Large Mold Steel

Jong‑Ho Shin,Jehyun Lee 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

A mold steel for plastic injection was subjected to low cycle fatigue (LCF) tests at temperatures of 25, 200, and 250 °C. LCFtests were carried out at a total strain amplitude (Δεt/2) from 0.004 to 0.012 under a constant strain rate of 0.01 s–1. Transmissionelectron microscope images showed that cyclic loading accelerated dislocation recovery as the LCF test temperatureincreased. The LCF life increased as a result of improvement in the ductility associated with dislocation recovery as the testtemperature increased. The LCF behavior at the test temperature range followed the Coffin–Manson equation. Empiricalequation was proposed to predict the LCF life of the mold steel within the test temperature range.

Nrf2-Heme oxygenase-1 modulates autophagy and inhibits apoptosis triggered by elevated glucose levels in renal tubule cells

Joo Heon Kim,김경민,Jin Uk Jeong,Jong-Ho Shin,신재민,방기태 대한신장학회 2019 Kidney Research and Clinical Practice Vol.38 No.3

Background: Autophagy is a highly balanced process in which lysosomes remove aged and damaged organelles and cellular proteins. Autophagy is essential to maintain homeostasis in the kidneys. Methods: Using human renal tubule cells HK-2, we assessed the impact of high glucose (HG) on autophagy. We also evaluated the capability of sulforaphane (SFN) to protect the HK-2 cells from HG-induced apoptosis by modulating autophagy. Results: SFN modulated autophagy and decreased apoptosis in the HK-2 cells that were cultured in 250 mM glucose medium for two days. The reactive oxygen species (ROS) levels increased, as expected, in the cells cultured in the 250 mM glucose medium. However, the SFN decreased the ROS levels in the HK-2 cells. The overexpression of heme oxygenase-1 (HO-1) by SFN decreased the expression of LC3 and beclin-1. LC3 and beclin-1 were involved in the downregulation of caspase-3 that was observed in the HG-induced cells. Conclusion: The activation of nuclear factor E2-related factor 2 (Nrf2)-HO-1 inhibited ROS expression and subsequently attenuated autophagy and cell apoptosis after HG injury was decreased. HG injury led to the activation of autophagy and HO-1 in order to combat oxidative stress and protect against cell apoptosis. Therefore, HO-1 activation can prevent ROS development and oxidative stress during HG injury, which considerably decreases autophagy and apoptosis.

朴木月 初期詩에 나타난 美的 距離의 樣相

신종호 崇實語文學會 2000 崇實語文 Vol.16 No.-

디스크형 캠기구 설계를 위한 순간속도중심설계법의 연구

신중호,김종수 國立 昌原大學校 産業技術硏究所 1994 産技硏論文集 Vol.8 No.-

As direct contact mechanisms, cam and follower mechanisms are used commonly in many machinery. Disk-typed cam mechanisms have 4 different types due to the different type of followers, such as reciprocating roller type, reciprocating flat-face type, oscillating roller type, and oscillating flat-face type. Depending on the shape of cam and type of follower, the motion of cam-follower mechanism is determined. Thus design procedure must be well defined for determining acculately the shape of cam corresponding to the given motion of follower. In this paper, an instant velocity center method is proposed. This method calculates the instant velocity centers of cam and follower in contact motion at any time. From geometric relationships on contact points of cam with follower, cam shape can be determined using the instant velocity centers. Also this paper presents 4 different cams for demonstration of the proposed design method and the results gives the exact solutions of cam design.

부분전용 회선 할당 방식에 의한 광역 회선 교환망(WAN)에 대한 성능분석

신호간,이정규 한양대학교 공학기술연구소 1994 공학기술논문집 Vol.3 No.1

In this paper, we have considered a wide area circuit-switched telecommunication network which consists of three metropolitan area networks(MANs) interconnected by a multiaccess communications channel, such as a satellite. The blocking probability of this network is computed, using a finite source traffic model, by setting up a Markov chain model, and employing results based on the reversibility of this chain to compute the underlying state probabilities. Local and long-distance blocking probabilities are calculated, each in terms of its two components: circuit blocking and destination busy probabilities. Partially dedicated circuit allocation policy is used in allocating the circuits of a MAN between its local and long-distance calls. To present explicit performance equations, a practically useful family of traffic connection patterns is employed, providing for the specification of the subscriber's local and long-distance destination groups and subgroups (so that network-wide traffic full-connectivity assumptions need not be made). Illustrative results and performance curves are given, indicating the various underlying system performance characteristics and tradeoffs. The method of performance analysis developed in this paper is expected to be very helpful to the performance analysis of interconnected MAN architectures, in which more than three MANs are involved.

苛性소다 處理에 依한 밀짚의 飼料價値 增進 硏究

辛炯泰,金贊昊,金鍾奭,宋永祿,林泰鎭 成均館大學校 1982 論文集 Vol.32 No.-

Nylon bag dry matter digestibility (NBDMD, %), nylon bag organic matter digestibility (NBOMD, %) and chemical compositions were analysed to evaluate the nutritive values of 5 varieties of NaOH-treated wheat straws (Jangkwang, Wonkwang, Suwon 210, Suwon 211, Naemil) by using Korean native male goats. Three grams of dried samples by grinding with 2.45㎜ Wiley mill screen were put into a bag 9×14㎠ made of 100 mesh nylon. These bags were put into the ventral sac of the rumen and taken out at the end of 72 hours. They were washed, dried in an oven at 105℃ for 24 hours and weighed “NBDMD” (%) and ashed in an muffle furnace at 600℃ or 24 hours and weighed “NBOMD”(%). The results which were obtained with this experiment were as follows: 1. Nylon bag dry matter digestibility (NBDMD, %) and nylon bag organic matter digestibility (NBOMD, %) of NaOH-treated wheat straws were highly significant different (p<0.01) in different levels of NaOH treatment and of different varieties of wheat straws. 2. The relationship between total mean NBDMD (%, Y_1) of 5 varieties of wheat straws and NaOH concentration (%, X) at 72 hours rumen incubation was: Y_1=34.57+3.56X(r=0.92^**) 3. The relationship between total mean MBOMD (%, Y_2) of 5 varieties of wheat straws and NaOH concentration (%, X) at 72 hours rumen incubation was: Y_2=32.02+2.46X(r=0.92^**) 4. The orders of NBDMD(%) and NBOMD(%) for 5 varieties of wheat straws were Suwon 210, Suwon 211, Naemil, Jangkwang, Wonkwang and Suwon 211, Suwon 210, Naemil, Jangkwang, Wonkwang, respectively. 5. The optimum level of NaOH for improving NBDMD(%) from 5 varieties of wheat straws, on the basis of Blaxter et al. (1961), was 6% NaOH.

강재 슬릿형 댐퍼를 부착한 철근콘크리트조 골조의 거동

신종익,이정한,송한범,강대언,오상훈,차승렬,이용재,김상대,이원호 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

This study investigates the performance of the reinforced concrete frame with the steel plate slit damper. The test was carried out to investigate the structural behavior between the reinforced concrete bare frame and the reinforced concrete frame with the steel plate slit damper. The test results showed that the energy absorption capacity of the damped-frame was several times larger than that of the bare frame. For the damage by the input energy is concentrated on the steel plate slit damper, the ductilities of the former structure were increased and the damaged frame can be reused after exchange the steel plate slit damper.

Hemodialysis에 관한 정신의학적 연구

신정호 大韓神經精神醫學會 1978 신경정신의학 Vol.17 No.4

A clinical study was conducted on the psychiatric problems manifested by 21 chronic renal failure patients on maintenance hemodialysis at Yonsei Medical Center. Structred interviews with the patients and family members were done at least twice on each patient and Zung's self-rating depression scale, Hamilton's anxiety and depression scales were administered. The data obtained were compared with those of both normal control and neurotic patients group. The results indiated that patients on the hemodialysis have confronted with serious personal, familial and socioeconomic stresses and they suffered from marked psychiatric symptoms such as depression, pessimistic idea, guilty feeling, psychomotor retardation, rejected feeling, increased dependency, irritability and insomnia. But they showed tendency to minimize or deny their problems and complaints, as reflected in the self-rating depression scale. Denial was considered to be the mian defense mechanism against chronic stress associated with the procedure. And the depression of those patients was characterized by the fact that female patients showed higher scores than males, and by the fact that the longer the duration of hemodialysis, the more severe the degree of depression and that comparing to neurotic patients, they showed higher scores in decreased libido, dissatisfaction and suicidal rumination in Zung's SDS. Also two case histories of acute psychotic episode were presented; they were characterized by relatively short-term progress of about 7 days with good prognosis and bizarre symptoms as mask like dull facial expression and symbolic expression of suicide and of conflit associated with death. Lastly, the possible roles of psychiatry for patients on the hemodialysis were discussed.

구미지역 상설시장의 유통업 현황분석 및 활성화 방안

신호균,김정태,송종호 한국의사결정학회 2002 경영과학연구 Vol.11 No.-

Due to a great difficulty of permanent market with the advent of great discount stores and foreign distributors, this paper is to analyze the current situation and to present suggestions for the development of the permanent market Gumi. To achieve the objective, a field study has been conducted using the questionaires for the consumers and the interviews with the merchants of the 5 major permanent markets in Gumi area. The study is based on the pilot study by civil servants and the representatives of the merchants. Considering the problems the permanent market in Gumi it is suggested that we approach not from the viewpoint of competitive relationship but from that of mutually cooperative relationship. Then, the distribution industry will be able to enhance the life quality of citizen and develop regional community.