• Tribology and Lubricants
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• 제29권3호
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• pp.180-185
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• 2013

The purpose of this study was to analyze the tribological characteristics of the Electronic control suspension System in a car. In the first example, the cilp used to attach the front electronic control suspension(ECS) system's control actuator was fastened very tightly. Thus, the wire was cut because of continual rotation of the shock-up shover piston rod used to adjust the height of the car. This verified the disconnection phenomenon where wire damaged makes it impossible for the ECS system to send signal to the actuator. The second example, involved a minute hole that allowed gas to leak from the ECS system. As a result, the height of the car verified the down phenomenon. In the third example, the resistance of a wire measured at $0.21{\Omega}$, when the G sensor was disconnected from the system. This verified the system shutdown and lighting of the ECS warning lamp because of body interference caused by a slight pressure on the battery cover. Therefore, quality control is always necessary to ensure safety and durability of a car.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 초전도 자성체
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• pp.55-58
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• 2002

PIT method which is used at fabricating Bi-2223/Ag HTS wire includes a drawing process, conventional deformation method. Drawing of meta1(Ag) and ceramic (BiSrCaCuO) composite is also difficult and significant for uniform deformation. In this paper, parameters of uniform deformation was studied at Bi-2223/ Ag multifilamentary HTS wire. Powder and rod as a starting precursor was compared at 55 filament and 54 filament Bi-2223/Ag HTS wire, respectively. Micro-hardness and area COV of the filaments was also evaluated when the diameters were decreased through drawing operations.

• 한국진공학회지
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• 제12권2호
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• pp.118-122
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• 2003

저압 MOCVD 장치를 이용하여 선택적 에피 성장 (selective area epitaxy) 기술을 개발하고, 이 기술을 이용하여 InGaAs/GaAs 양자세선(quantum wire) 구조를 성장하였다. $SiO_2$로 선택적으로 마스킹 된 GaAs 기판위에 AIGaAs/GaAs 다충 구조 및 InGaAs/GaAs 양자세선 구조를 저압 MOCVD 방법으로 성장하였다. 매끄러운 사면을 갖고 끝 부분이 뽀쪽한 삼각형 구조의 양자세선 구조가 선택적 에피 성장법에 의해 자발적으로 형성되었다. 선택적 에피층 성장을 위한 최적 조건을 알기 위해 먼저 GaAs/AlGaAs 다층구조에 대하여 여러 가지 성장변수들에 대하여 조사하였다. 성장 변수들은 성장률(growth rate), V/III 비 및 성장온도, 패턴의 정렬 방향 등이다. 양자세선에서 나오는 발광은 975 nm로 분석되었다. 측정 온도가 증가됨에 따라 삼각형 구조의 사면의 양자우물에서 나오는 발광은 급격하게 감소하였다. 그러나 양자세선에서 나오는 발광은 양자우물에서 나오는 발광에 비해 서서히 감소하였고, 50 K 이상의 온도에서는 양자세선에서 나오는 발광의 세기가 더 커졌다.

• 한국재료학회지
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• 제25권6호
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• pp.265-268
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• 2015

ZnO micro/nanocrystals at large scale were synthesized through the thermal evaporation of Al-Zn mixtures under air atmosphere. The effect of synthetic temperature and time on the morphology of the micro/nanocrystals was examined. It was found that the temperature and time affected the morphology of the ZnO crystals. At temperatures below $900^{\circ}C$, no crystals were synthesized. At a temperature of $1000^{\circ}C$, ZnO crystals with a rod shape were synthesized. With an increase in temperature from $1000^{\circ}C$ to $1100^{\circ}C$, the morphology of the crystals changed from rod shape to wire and granular shapes. As the time increased from 2 h to 3 h at $1000^{\circ}C$, tetrapod-shaped ZnO crystals started to form. XRD patterns showed that the ZnO crystals had a hexagonal wurtzite structure. EDX analysis revealed that the ZnO crystals had high purity. It is believed that the ZnO nanowires were grown via a vapor-solid mechanism because no catalyst particles were observed at the tips of the micro/nanocrystals in the SEM images.

• 약학회지
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• 제58권5호
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• pp.300-306
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• 2014

Ethanol consumption causes psychomotor alterations. Hovenia Semen seu Fructus (HS), widely distributed in Korea, China, and Japan, has been reported to have beneficial effects on acute alcohol-induced liver injury. The present study sought to assess the effects of HS extract on ethanol-induced psychomotor alterations in rats. Sprague-Dawley rats were orally (p.o.) given ethanol (4 g/kg) (ethanol group) to induce psychomotor alterations. A separate group (HS-treated groups), were treated with different dosages of HS (50, 100, and 200 mg/kg, p.o.), 30 minutes before ethanol treatment. The control group received only the vehicle (saline). Ethanol-induced psychomotor alterations were evaluated in the open-field, rota-rod, hanging wire, and cold swimming test. In addition, blood ethanol and acetaldehyde concentrations were also measured. Behavioral evaluations and blood analysis were carried out 0.5, 1, 2, 4, and 8 hours after ethanol administration. Pre-treatment of HS ameliorated ethanol-induced alterations in the open-field, rota-rod, and cold swimming test, significantly evident in 2 and 4 hours after ethanol treatment. These improvements coincided with decrease in blood ethanol and acetaldehyde concentration. Based on these results, the present study suggests that HS may have ameliorating effects against ethanol-induced psychomotor alterations.

• 한국산업융합학회 논문집
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• 제25권2_2호
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• pp.199-208
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• 2022

The steel wire or steel bar processing process applied to the manufacture of various bolts and power transmission shafts was improved by applying in-line phosphate film treatment technology. By applying a polymer lubricant for a non-reactive metal forming process and a non-reactive non-phosphorus lubricating coating agent, the film formation for each process time was comparatively analyzed and reviewed. Compared to the nine processes applied previously, the in-line phosphate film treatment technology applied with only two processes has been effectively improved in terms of reduction of treatment time, reduction of facility installation area, prevention of water pollution due to wastewater, and non-use of ozone-depleting substances. In addition, it was found that it can have an important effect on productivity improvement and price competitiveness from the simplification of quality control and process control as well as improvement of the working environment.

• Nuclear Engineering and Technology
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• 제48권5호
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• pp.1083-1095
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• 2016

The design of Prototype Gen-IV Sodium-Cooled Fast Reactor (PGSFR) has been developed and the validation and verification (V&V) activities to demonstrate the system performance and safety are in progress. In this paper, the current status of test activities is described briefly and significant results are discussed. The large-scale sodium thermal-hydraulic test program, Sodium Test Loop for Safety Simulation and Assessment-1 (STELLA-1), produced satisfactory results, which were used for the computer codes V&V, and the performance test results of the model pump in sodiumshowed good agreement with those in water. The second phase of the STELLA program with the integral effect tests facility, STELLA-2, is in the detailed design stage of the design process. The sodium thermal-hydraulic experiment loop for finned-tube sodium-to-air heat exchanger performance test, the intermediate heat exchanger test facility, and the test facility for the reactor flow distribution are underway. Flow characteristics test in subchannels of a wire-wrapped rod bundle has been carried out for safety analysis in the core and the dynamic characteristic test of upper internal structure has been performed for the seismic analysis model for the PGSFR. The performance tests for control rod assemblies (CRAs) have been conducted for control rod drive mechanism driving parts and drop tests of the CRA under scram condition were performed. Finally, three types of inspection sensors under development for the safe operation of the PGSFR were explained with significant results.

• 한국재료학회지
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• 제28권10호
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• pp.578-582
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• 2018

ZnO crystals with different morphologies are synthesized through thermal evaporation of the mixture of Zn and Cu powder in air at atmospheric pressure. ZnO crystals with wire shape are synthesized when the process is performed at $1,000^{\circ}C$, while tetrapod-shaped ZnO crystals begin to form at $1,100^{\circ}C$. The wire-shaped ZnO crystals form even at $1,000^{\circ}C$, indicating that Cu acts as a reducing agent. As the temperature increases to $1,200^{\circ}C$, a large quantity of tetrapod-shaped ZnO crystals form and their size also increases. In addition to the tetrapods, rod-shaped ZnO crystals are observed. The atomic ratio of Zn and O in the ZnO crystals is approximately 1:1 with an increasing process temperature from $1,000^{\circ}C$ to $1,200^{\circ}C$. For the ZnO crystals synthesized at $1,000^{\circ}C$, no luminescence spectrum is observed. A weak visible luminescence is detected for the ZnO crystals prepared at $1,100^{\circ}C$. Ultraviolet and visible luminescence peaks with strong intensities are observed in the luminescence spectrum of the ZnO crystals formed at $1,200^{\circ}C$.

• 한국주조공학회지
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• 제14권5호
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• pp.464-470
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• 1994

The horizontal continuous casting method with the heated mold was applied to study the solidification structures of the pure Al and Al-0.5wt%Si and Al-1.0wt%Si alloy rods. The results could be summarized as follows: 1. The S/L interface structures of pure Al represented the hexagonal cells at the casting speed of 590 and 350mm/min, respectively. However, the hexagonal cells became irregular as the casting speed and(or) Si amount increased. 2. The striation increased as the Si amount and casting speed increased and was found to result from the occurrence of growth twin crystals by XRD analysis. 3. The striation did not affect the mechanical and electrical property of the drawn wire from the casted rod. This means the striation is not a serious defect which has to consider in the production of micro-sized fine wire in the drawing process.

• 한국전기전자재료학회논문지
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• 제14권12호
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• pp.1032-1040
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• 2001

In order to apply the partial discharge measuring technique utilizing electrical pulse to the transformer at sites, this paper describes the measuring technique obtaining only the signals due to internal partial discharge in the transformer, but the noises due to external corona which has been a major problem so far. At first, partial discharge and corona noise were simultaneously generated in the model transformer by using needle-plane electrodes and rod-sphere electrodes out of it in a high voltage laboratory, respectively. It was verified that only the partial discharge signals in the transformer could be measured by removing the noise signals from the superposed signals of partial discharges and noises on the grounding wire of the model transformer. By application to a 345kV transformer in service, it was also confirmed that the partial discharge could be on-line monitored by removing the noise signals measured by the inductance sensor on the grounding wire of a 154kV lightning arrester from the superposed signals of internal partial discharge and external corona noise measured by bushing tap coupler of the transformer.