Microstructure‑Strengthening Interrelationship of an Ultrasonically Treated Hypereutectic Al–Si (A390) Alloy

Soo‑Bae Kim,Young‑Hee Cho,Jae‑Gil Jung,Woon‑Ha Yoon,Young‑Kook Lee,Jung‑Moo Lee 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.6

Ultrasonic melt treatment (UST) was applied to an A390 hypereutectic Al–Si alloy in a temperature range of 750–800 °Cand its influence on the solidification structure and the consequent increase in strength was investigated. UST at such a hightemperature, which is about 100 °C above the liquidus temperature, had little effect on the grain refinement but enhanced thehomogeneity of the microstructure with the uniform distribution of constituent phases (e.g. primary Si, α-Al and intermetallics)significantly refined. With the microstructural homogeneity, quantitative analysis confirmed that UST was found tosuppress the formation of Cu-bearing phases, i.e., Q-Al5Cu2Mg8Si6, Al2Cuphases that form in the final stage of solidificationwhile notably increasing the average Cu contents in the matrix from 1.29 to 2.06 wt%. A tensile test exhibits an increasein the yield strength of the as-cast alloy from 185 to 208 MPa, which is mainly associated with the solute increment withinthe matrix. The important role of UST in the microstructure evolution during solidification is discussed and the mechanismcovering the microstructure-strengthening interrelationship of the ultrasonically treated A390 alloy is proposed.

관상동맥 스텐트 내 재협착의 발생에 미치는 임상적 관동맥 조영술적 요인들

윤혁준,김기식,박형섭,이영수,현대우,한성욱,허승호,김윤년,김권배,박남희,원경숙 대한순환기학회 2003 Korean Circulation Journal Vol.33 No.12

임상 증상이 심하지 않은 심낭 삼출 환자의 장기 추적 결과

배장호,김기식,강미숙,남명희,김미정,김민수,김기영,님창욱,김윤년,김권배,정시전,김여희 대한순환기학회 1999 Korean Circulation Journal Vol.29 No.7

천연자원의 간기능 보호 효과에 관한 연구 : Benzo(a)pyrene에 의한 간기능 장해에 미치는 황금(Scutellaria baicalensis)의 영향 The Effect of Scutellariae Radix on the Benzo(a)pyrene-induced Hepatotoxicity in Rats

윤수홍,조수열,배선희,박상학 효성여자대학교 부설 한국환경위생연구소 1991 환경위생연구 Vol.1 No.1

환경 중의 어디에나 분포하여 인체에 발암작용을 일으키는 대표적인 약물 benzo(a)pyrene를직접 경구투여하고.동시에 간보호물질로서 황금을 전처리 투여하여 그 독성 및 손상 회복호과를 혈청 및 간에서의 효소활성을 측정하여 다음과 같은 결론을 얻었다. 1. 황금 수용액의 전처리로 혈칭에서 LDH, AST 및 ALT활성은 beozo(a)pyrene단독투여군에비하여 감소하였으며 ALT는 2,4주째에 유의성 있는 감소를 보였으나 ALP활성은 전 실험군과 시간경과사이에 별다른 유의성이 없었다. 2. 간장의 LDH, ALP, ALT, AST의 효소활성은 황금수용액의 투여로 benzo(a)pyrene 단독투여군에 비해 유의성 있는 회복을 보였으며 LDH의 경우는 2, 3, 4주에 매우 큰 효과를얻었으며 ALP의 경우 4주째에서 유의성 있게 회복되는 경향을 보였다. This study was conducted in an attempt to investigate the effectsof Scutellariae Radix on the activities of serum and liver enzyme and to evaluatethe utility of Scultellariae Radix as a hepatotropic agents in liver disease The results were as follows ; 1. Significantly increased enzyme activity was noted in benzo(a)pyrene-intoxica-ted rats. 2. Scutellariae Radix administration prevented the leackage of LDH, ALP, ALTand AST in serum. 3. Scutellariae Radix administration did not affect on the serum ALP activity. 4. The B(a) P induced liver toxicity was significantly decreased in ScutellariaeRadfx administration.

국민학교 저학년 교육과정 재구성을 위한 기초연구

배진수,신윤철 晋州敎育大學校 初等敎育硏究所 1994 初等敎育硏究 Vol.4 No.-

Permanent wave와 Bleaching에 의한 모발손상에 관한 연구

배선향,윤수홍,이도영 한국위생과학회 2002 한국위생과학회지 Vol.8 No.2

This study investigated the changes of hair cuticle shape by means of scanning Electron Microscope(SEM) after permanent waving and bleaching, according to different types of chemicals(perm, bleach)and of temperatures(25℃, 50℃). The subjects were Korean students in their twenties who did not go on a diet, took no drugs, and had virgin hair. Virgin hair remained dense without being splayed off the scale, overlapped in a regular basis, and clear of the boundary between scales. But, the scale of hair cuticle had been splayed, separated, and lost by permanent waving and bleaching with hair chemicals. The hair cuticle that was permanent waved at 25℃ once and three times showed almost virgin hair, and the cuticle of hair permanent waved at 50℃ once was just a little splayed, so it seemed that perm treatment frequency and the permanent wave lotion with low pH were not major factors at low temperature. However, repeating the performance of bleaching, though at low temperature, was more major harmful factor than high temperature. This result reveals that a chemical of pH 11.0 for bleach damages hair severely leaving splayed and cracked in the whole hair, and maker\s column wrinkled scales regardless of temperature.

혐기성세균모델을 이용한 봉함제(Sealer)의 미세누출에 관한 연구

윤수한,오태석,배용규 大韓齒科保存學會 2000 Restorative Dentistry & Endodontics Vol.25 No.2

불안정한 지지면에서의 평형 훈련이 편마비 환자의 균형 능력에 미치는 영향

배수찬,김근조,윤홍일 대한정형물리치료학회 2001 대한정형도수물리치료학회지 Vol.7 No.2

The purpose of this study was to investigate the balancing training effect on weight bearing ratio and postural sway on the unstable surface for the CVA patients with balance disability. The inclusion criteria were walking independently 20m distances. Eighteen subjects, 4 with right and 14 with left hemiplegic patients were participated in this study. The range of age was from 35 to 75 and the duration from onset time was from 1 to 38 months. The intervention program including balancing training that they were introduced for 10 minutes every other day during 12 weeks to experimental group, and general therapeutic exercise to control group. The result of this study were as following: 1. The balancing training on the unstable surface showed that the postural sway of left/right distribution would appear more effective on sitting with eyes opened. 2. The balancing training on the unstable surface showed that the postural sway of forward/rear distribution, left/right distribution and distance would appear more effective on standing with eyes opened. 3. The balancing training on unstable surface would increase more effective on the weight-bearing ratio of left/right difference and frequency. 4. The balancing training on unstable surface was statistical significant on the postural sway of left/right distribution and area in experimental group, and it was statistical significant on the postural sway of forward/rear distribution, left/right distribution and distance in control group, too.

은행잎 추출물이 협심증 환자의 내피 세포 기능에 미치는 장단기 효과

배장호,김기식,이인규,김여희,김민수,김기영,남창욱,김윤년,김권배,정시전 대한순환기학회 1999 Korean Circulation Journal Vol.29 No.9

Permanent waVe와 Decoloration에 의한 모발손상에 관한 연구

배선향,윤수홍,이도영 한국위생과학회 2002 한국위생과학회지 Vol.8 No.2

펌 및 탈색 시 모발 손상을 줄이기 위한 기초자료를 제공하기 위해 20대 여대생의 건강한 모발을 펌 및 탈색을 하면서 전자 현미경으로 그 형태적 변화를 조사한 결과는 다음과 같았다. 자연 모발은 굵기가 60~80 ㎛인 비교적 가는 건강한 직모로 나타났다. 모표피(hair cuticle)의 비늘은 벌어지거나 벗겨짐이 서로 밀착되어 있었으며, 비늘의 겹쳐진 폭이 규칙적이었다. 또한 비늘 사이의 경계가 뚜렷하였고, 비늘의 표면은 매끈하였다. 25 ℃에서 1회 펌을 한 모발의 경우 한 부위에서만 비늘의 가장자리가 벌어졌을 뿐 다른 부위에서는 비늘의 벌어짐이 없이 밀착된 상태로 나타났다. 25 ℃에서 3회 펌을 한 모발의 경우에는 네 부위에서 비늘의 가장자리가 약간 더 벌어졌으나 25 ℃에서 1회 펌을 한 모방의 손상 정도와 큰 차이가 없었다. 50 ℃에서 1회 펌을 한 모발은 전체부위에서 비늘이 약간씩 벌어졌다. 25 ℃에서 3회 펌을 한 모발에 비해 비늘의 형태가 더 손상된 형태로 나타났다. 50 ℃에서 3회 펌을 시술한 모발은 심하게 손상되었다. 약 40 %의 비늘 가장자리가 벌어졌고, 약 10 %의 비늘은 미세한 주름이 생겼으며, 모발의 한 부위에는 구멍이 생겼다. 25 ℃에서 1회 탈색한 모발의 경우 전체에서 비늘이 벌어졌으며, 두 부위에서는 비늘이 탈락되어 비늘의 간격이 불규칙하였고, 전체 모발 중에서 약 15 %의 비늘에 세로 주름이 나타났다. 25 ℃에서 3회 탈색한 경우에는 모발 전체에서 비늘이 용해되어 두꺼워졌고, 모표피의 문리가 일정하지 않았으며, 모발의 몇몇 부위에 구멍이 생겼다. 50 ℃에서 1회 탈색한 경우 90 % 이상의 비늘이 벌어졌고, 약 25 %의 비늘에 뚜렷한 세로 주름이 생겼으며, 한 장의 비늘에 작은 구멍이 나타났다. 50 ℃에서 3회 탈색한 경우에는 모발 전체에서 모표피의 문리가 없어졌고, 용해된 비늘이 뭉쳐 있었으며, 또한 작은 구멍들이 여러 부위에 생겼다. 펌을 한 경우보다 탈색한 경우 모방의 손상 정도가 큰 것으로 나타났으며, 가장 손상의 정도가 큰 것은 50 ℃에서 3회 탈색한 경우로 나타났다. The morphological changes were investigated for the purpose of suggest the basic information to lesson hair damages by perm and decoloration. Women hairs were permed and decolored one time and three times at different temperature(25 ℃, 50 ℃), respectively. Then, the hairs were photographed with scanning electron microscope. The virgin hairs, which were not permed and not decolored, were morphologically healthy. Hair cuticle scales were not splayed and overlapped regularly. Perm hairs, which were treated one time at 25 ℃, were relatively healthy though one scale of hair cuticle was splayed. and, on the occasion of perm hairs treated three times at 25 ℃, four scales of hair cuticle were splayed. Hairs, which were permed at 50 ℃, were more damaged than those which permed at 25 ℃. Hair scales, which were permed at 50 ℃, were almost splayed. On the occasion of perm hairs treated three times at 50 ℃, 10 percentages of hair scales were wrinkled, and one scale was holed. Hair scales, which were decolored one time at 25 ℃ were almost splayed, and 15 percentages of hair scales were wrinkled. Hair scales, which were decolored three times at 25 ℃, were almost melted and thickened. 90 percentages of hair scales, which were decolored one time at 50 ℃, were splayed, and 25 percentages of hair scales were wrinkled. On the occasion of decoloration hairs treated three times at 50 ℃, the boundaries between scales were almost disappeared, and hair scales were melted and were agglomerated. Hairs, which were decolored, were more morphologically damaged than those which premed.