• 연구논문집
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• 통권29호
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• pp.141-149
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• 1999

Brazing of Fe-Cr-Al alloy was carried out at $1200^{\circ}C$ in vacuum furnace using nickel-based filler metals : BNi-5 powder(Ni-Cr-Si-Fe base alloy} and MBF-50 foil (Ni-Cr-Si-B). The effect of boron content on the stability of oxide scale on the brazed joint was investigated by means of cyclic oxidation test performed at $1050^{\circ}C$ and $1200^{\circ}C$. Apparently, the joints brazed with MBF-50 containing boron showed relatively stable oxidation rates compared to boron-free BNi-5 at both temperatures. However, it was considered that the slower weight loss of MBF-50 brazed specimen wasn’t resulted from the low oxidation rate but from the spallation of oxide layer. The oxide layer consisted of thick spinel oxide on the surface and $Al_2 O_3$ internal oxide layer along the interface between mother alloy and braze, the mother alloy was also eroded seriously by the formation of spinel oxides such as $FeCr_2 O_4$ and $NiCr_2 O_4$ on the surface, likely to be induced by the change of oxide forming mechanism due to diffusion of boron from the braze. On the contrary, the joint brazed with BNi-5 showed the good oxidation resistance during the cyclic oxidation test. It seems that the oxidation can be retarded by the formation of stable $Al_2 O_3$ layer at the surface.

• 한국재료학회지
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• 제15권6호
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• pp.399-407
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• 2005

The effect of IN738 additive powder on microstructure and mechanical properties of the wide-gap region brazed with BNi-3 filler metal powder was investigated. The wide-gap brazing was conducted in a vacuum of $2\times10^{-5}torr\;at\;1200^{\circ}C$ with various powder mixing ratios of additive to filler powders. The microstructures of the wide-gap brazed region were analyzed by SEM and AES. The region brazed with only BNi-3 filler metal powder had a microstructure consisted of proeutectic, binary eutectic and ternary eutectic structure, while that brazed with a mixture of IN738 additive powder and BNi-3 filler metal powder had a microstructure consisted of IN738 additive powder, binary eutectic of $Ni_3B-Ni$ solid solution and (Cr, W)B. The fracture strength of the wide-gap brazed region was about 680 MPa regardless of the additive powder mixing ratios. Cracks were initiated at the (Cr, W)B and binary eutectic of $Ni_3B-Ni$ solid solution, and propagated through them in the wide-gap brazed region, which lowered the fracture strength of the region.

• The Korean Journal of Pain
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• 제26권3호
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• pp.255-264
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• 2013

Background: We investigated the effects of pre-emptive administration of ketamine and norBNI on pain behavior and the expression of DREAM, c-Fos, and prodynorphin proteins on the ipsilateral side of the rat spinal cord at 2 and 4 hours after formalin injection. Methods: Eighty-four male Sprague Dawley rats were divided into 4 major groups consisting of control rats (C) (n = 12), rats given only formalin injections (F) (n = 24), and rats treated with pre-emptive administration of either ketamine (K+F) (n = 24) or norBNI (N+F) (n = 24). The non-control groups were further divided into subgroups consisting of rats that were sacrificed at 2 and 4 hours (n = 12 for each group) after formalin injection. Pain behavior was recorded for 1 hour. After 2 and 4 hours, the rats were sacrificed and the spinal cords (L4-L5 sections) were removed for immunohistochemistry and Western blot analysis. Results: The pain behavior response was reduced in the K+F group compared to the other groups during the second phase of the formalin pain response. We detected an increase in the nuclear DREAM protein level in the K+F group at 2 and 4 hours and a transient decrease in the N+F group at 2 hours; however, it increased at 4 hours after injection. Fos-like immunoreactivity (FLI) and Prodynorphin-like immunoreactivity (PLI) neurons decreased in the K+F group but increased in the N+F group at 2 hours after injection. While FLI decreased, PLI increased in all groups at 4 hours after injection. Conclusions: We suggest that NMDA and kappa opioid receptors can modulate DREAM protein expression, which can affect pain behavior and protein transcriptional processes at 2 hours and bring about either harmful or protective effects at 4 hours after formalin injection.

• 열처리공학회지
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• 제22권4호
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• pp.210-216
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• 2009

Stainless steel EGR cooler of diesel engine is widely used to prevent the corrosion due to the content of sulfur in diesel fuel. The strength of brazed joint between stainless steel materials is very important. It is essential to observe the spreading ratio of the filler metals under the condition of deoxidation or vacuum during heating process. In this experiment, spreading ratio was tested to find the optimum brazing condition for stainless steel using brazing filler metals of FP-613, BNi-2 and BNi-5 on sus304 and sus410. Anti-corrosion tests were also performed on the above filler metals with solution of 5% $H_2SO_4$, 65% $HNO_3$ and 5% $NH_4OH$. Consequently FP-613 has good ability for anti-corrosion with 30% of chromium content compared with other filler metals. The optimum brazing conditions are occurred at $960^{\circ}C$ for 90 min. and at $1090^{\circ}C$ for 50 min. at the same degree of vacuum, $2{\sim}3{\times}10^{-3}$ Torr.

• 한국자기학회지
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• 제10권1호
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• pp.1-6
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• 2000

단롤법으로 제조된 비정질 F $e_{79.7}$ S $i_{9.3}$ $B_{9.7}$N $i_{1.4}$ 합금 리본의 직류중첩특성을 향상시키기 위하여 46$0^{\circ}C$에서 열처리 시간에 따른 자기적 특성과 미세구조의 변화를 조사하였다. 직류중첩특성은 미세구조의 변화와 밀접한 연관성이 있음이 관찰되었다. $\alpha$-Fe 결정립의 크기가 200~300 nm일 경우 가장 효과적으로 자벽 이동을 방해하여 최대 직류중첩특성을 나타내었다. 수지상정의 성장 형태와 분포는 2개의 영역으로 분리되어 나타나며, 이는 리본 제조 시 발생하는 리본 내 과냉도의 차이에 기인한 것이다.한 것이다.

• Journal of Welding and Joining
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• 제2권1호
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• pp.18-24
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• 1984

With the use of a new method the deformation mechanism of high-temperature-brazed joints can be obtained in a very short time. For that purpose a SEM(Scanning Electron Microscope) was equipped with a high temperature tensile testing machine. By means of SEM-investigation the damage behaviour of high-temperature-brazed joints is exa mined at elevated temperature. Based on these it is possible to make a qualification of the influence over single parts on the damage beginning and behaviour in dependence of temperature. This shall be shown exemplarily for the high temperature material NiCr20TiAl (Nimonic 80A).

• Journal of Korean Neurosurgical Society
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• 제59권6호
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• pp.637-642
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• 2016

Objective : Although many treatment modalities have been introduced for trigeminal neuralgia (TN), the long-term clinical results remain unsatisfactory. It has been particularly challenging to determine an appropriate treatment strategy for patients who have responded poorly to initial therapies. We analyzed the surgical outcomes in TN patients who failed prior treatments. Methods : We performed a retrospective analysis of 37 patients with recurrent or persistent TN symptoms who underwent surgery at our hospital between January 2010 and December 2014. Patients with follow-up data of at least one year were included. The prior treatment modalities of the 37 patients included microvascular decompression (MVD), gamma knife radiosurgery (GKRS), and percutaneous procedures such as radiofrequency rhizotomy (RFR), balloon compression, and glycerol rhizotomy (GR). The mean follow-up period was 69.9 months (range : 16-173). The mean interval between the prior treatment and second surgery was 26 months (range : 7-123). We evaluated the surgical outcomes using the Barrow Neurological Institute (BNI) pain intensity scale. Results : Among the 37 recurrent or persistent TN patients, 22 underwent MVD with partial sensory rhizotomy (PSR), 8 received MVD alone, and 7 had PSR alone. Monitoring of the surgical treatment outcomes via the BNI pain intensity scale revealed 8 (21.6%) patients with a score of I, 13 (35.1%) scoring II, 13 (35.1%) scoring III, and 3 (8.2%) scoring IV at the end of the follow-up period. Overall, 91.8% of patients had good surgical outcomes. With regard to postoperative complications, 1 patient had transient cerebrospinal fluid rhinorrhea (2.7%), another had a subdural hematoma (2.7%), and facial sensory changes were noted in 8 (21.1%) patients after surgery. Conclusion : Surgical interventions, such as MVD and PSR, are safe and very effective treatment modalities in TN patients who failed initial or prior treatments. We presume that the combination of MVD with PSR enabled us to obtain good short- and long-term surgical outcomes. Therefore, aggressive surgical treatment should be considered in patients with recurrent TN despite failure of various treatment modalities.

• 한국기계기술학회지
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• 제13권2호
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• pp.137-143
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• 2011

Fuel Test Loop(FTL) is a facility which could conduct a fuel irradiation test at HANARO(High-flux Advanced Neutron Application Reactor). FTL simulates commercial NPP's operating conditions such as the pressure, temperature and neutron flux levels to conduct the irradiation and thermo-hydraulic tests. The In-Pile Test Section(IPS) installed in HANARO FTL is designed as a pressure vessel design conditions of $350^{\circ}C$, 17.5MPa. The instrumentation MI-cables for thermocouples, SPND and LVDT are passed through the sealing plug, which is in the pressure boundary region and is a part of instrumentation feedthrough of MI-cable. In this study, the brazing method and performance test results are introduced to the sealing plug with BNi-2 filler metal, which is selected with consideration of the compatibility for the coolant. The performance was verified through the insulation resistance test, hydrostatic test, and helium leak test.

• Journal of Microbiology and Biotechnology
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• 제14권3호
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• pp.607-611
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• 2004

Glycinin, one of the predominant storage proteins in soybeans, was examined as to whether it could be used as a calcium-binding mediator after chemical phosphorylation and enzymatic hydrolysis. Glycinin is composed of six subunits. One of the proglycinin subunits $(A_{la}B_{lb})$ was overexpressed in E. coli to obtain nonphosphorylated proteins with homogeneity. To investigate the enhanced calcium-binding properties of the phosphopeptides, the proglycinin was purified, phosphorylated, and hydrolyzed with trypsin. The proglycinin expressed in E. coli was purified by ammonium sulfate precipitation, ion-exchange chromatography, and cryoprecipitation. Chemical phosphorylation by sodium trimetaphosphate was performed to obtain phosphorylated proglycinin. After the phosphorylation, one-dimensional isoelectric focusing gel electroanalysis confirmed the phosphorylation of the proglycinin. The phosphorylated peptides were then hydrolyzed with trypsin, followed by a binding reaction with calcium chloride. The calcium-bound phosphopeptides were finally separated using immobilized metal $(Ca^{2+})$ chromatography. Consequently, a limited tryptic hydrolysate of the isolated phosphopeptides exhibited an enhanced calcium-binding ability, suggesting the potential of glycinin phosphopeptides as a calcium-binding mediator with greater availability.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.1267-1274
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• 2021

This study aims to analyze the effect of corporate communication and service quality on loyalty mediating satisfaction. The population of this study is 384 Islamic bank customers in North Sumatra. This research is quantitative research using the survey method. The number of research samples was 384 customers. Characteristics of this research sample were (1) Savings customers who actively carried out transactions in Islamic banks (2) Savings customers who had used bank services for at least 1 year (3) Savings customers who used services directly and individually. The data analysis technique used in this study was the Partial Least Squares-Structural Equation Model (SEM-PLS) analysis technique, using Warp-PLS 3.0 software. This study investigates the largest Islamic banks in North Sumatra, namely Bank Syariah Mandiri, Bank BNI Syariah, and Bank BRI Syariah. The results show that company communication has a positive and significant effect on satisfaction, service quality has a positive and significant effect on satisfaction, company communication has a positive and significant effect on loyalty, service quality has a positive and significant effect on loyalty, satisfaction has a positive and significant effect on loyalty. There is also a significant effect of satisfaction on the relationship between company communication and loyalty, and the relationship between service quality and loyalty. This study contributes to Islamic banking to increase customer loyalty.