Effect of Ultrasonic Melt Treatment on Solidification Microstructure of Al–5Ti–1B Alloy Containing Numerous Inoculant Particles

Soo‑Bae Kim,Jae‑Gil Jung,Young‑Hee Cho,Su‑Hyeon Kim,Kwangjun Euh,Jung‑Moo Lee 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

The effect of ultrasonic melt treatment (UST) on the solidification microstructure of an Al–5Ti–1B alloy containing highvolumefractions of Al3Tiand TiB2particles is investigated for various UST times with different melt holding times. Theas-cast Al–5Ti–1B alloy is composed of TiB2and polygonal Al3Tiparticles (present prior to UST), plate-like Al3Tiparticles,and Al grains (formed during UST and/or solidification). The UST causes a size reduction and homogeneous distributionof the TiB2-agglomerated region containing many submicron-sized TiB2particles pushed to the grain boundaries. The USTslightly decreases the size and improves the distribution of polygonal Al3Tiparticles enriched in the TiB2-agglomeratedregion. Unlike the TiB2and polygonal Al3Tiparticles, which exhibit a minor refining effect, the plate-like Al3Tiparticlesshow a significant refinement with UST application. The UST has a significant effect on the size distribution of Al grains byinducing the formation of medium-sized grains at the expense of small and large grains; however, it only has a slight effecton grain refinement. The degree of microstructure modification increases with increasing UST time but decreases with meltholding time after UST. The mechanisms for the refinement and dispersion of the TiB2and Al3Tiparticles and Al grains arediscussed considering fragmentation, nucleation, and growth behaviors induced by the UST and subsequent solidification.

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.

A simple approach to estimate the mechanical properties of collagen-like microfibrils surrounded by water

Young-june Yoon,Cheol-soo Bae,Ho-sik Park 한국멀티미디어학회 2010 한국멀티미디어학회 국제학술대회 Vol.2010 No.-

The effective Young's modulus of a microfibril surrounded by water may be simply calculated by using the upper (Voigt) and lower (Reuss) bounds. The result is compared to the Young's modulus estimated by using the Steered Molecular Dynamics (SMD) (Zhang et al. 2007). Our result shows 9.2% difference from the result estimated by SMD, but the steps using these bounds are much simpler than SMD..

관동맥질환에서 저밀도 지단백 입자 크기의 분포

임효영,김인숙,승기배,강동헌,전두수,장기육,박준철,이수영,홍순조,최규보 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.8

Erosive adenomatosis of the nipple presenting early improvement after short-term cryotherapy

( Kyung-nam Bae ),( Kihyuk Shin ),( Woo-il Kim ),( Min-young ),( Yang Won-ku Lee ),( Hoon-soo Kim ),( Hyun-chang Ko ),( Byung-soo Kim ),( Moon-bum Kim ),( Gun-wook Kim ) 대한피부과학회 2019 대한피부과학회 학술발표대회집 Vol.71 No.1

Erosive adenomatosis of the nipple (EAN) is a rare benign neoplasm characterized by the erosion of the nipple forming crust with serous or bloody discharge. Although there is no pronounced link between its nature course with the malignant transformation, the erosive deformity is directly related to the recurrent functional discomfort and cosmetic problem, resulting in deterioration of the quality of life. A 22-year old woman visited the breast clinic for her persistent deformity of the left nipple. She underwent a core-needle biopsy of a breast mass, which was incidentally found during a breast examination. However, no additional abnormalities were found except for fibrocystic change, and then visited to our clinic for evaluation of the skin lesion. The physical examination revealed serous and bloody erosion on top of the nipple with loss of half of its normal structure. The skin biopsy showed hyperplasia of the tubular structure composed of layers of cuboidal cells, but no atypia or pleomorphism. Then she received four times of cryosurgery every six-weeks, and after 6 months the nipple almost completely healed only remaining a tiny slit-like hole. Although the first choice of treatment for EAN is local excision, it is not quite feasible approach in young-aged female patients given the unsatifactory cosmetical outcomes and the anxiety for invasive procedure. Cryotherapy could be one of the acceptable option for the treatment of EAN.

복합재료역학을 이용한 콜라겐 단백질 마이크로피브릴의 탄성율 예측 개선

윤영준,배철수,Yoon, Young-June,Bae, Cheol-Soo 대한의용생체공학회 2010 의공학회지 Vol.31 No.3

The effective Young’s modulus of a microfibril surrounded by water may be simply calculated by using the upper (Voigt) and lower (Reuss) bounds, which is one way to estimate the Young’s modulus in composite materials. The Steered Molecular Dynamics (SMD) has been used for estimating the Young’s modulus of a microfibril surrounded by water. In this paper, the result estimated by the upper (Voigt) and lower (Reuss) bounds shows 9.2% to 21.8% discrepancy from the result estimated by SMD, but introducing “efficiency of reinforcement parameter” removes the discrepancy and shows good agreement with the result estimated by SMD. We found the best fit for the Young’s modulus against the size of the gap between microfibrils. Also the steps using these bounds are much simpler than SMD.

2005년(年) 여름 중국(中國) 대련시(大連市) 여성(女性) 스트리트 패션 분석(分析)

천지영 ( Jee Young Cheon ),배수정 ( Soo Jeong Bae ) 한국패션비즈니스학회 2006 패션 비즈니스 Vol.10 No.2

The purpose of this study is to analyze the street style of women in Dalian, China. 1.185 females of Dalian central street have participated for the survey of this study. This study analyzes characterization of the street style and, classifies it`s characteristics by age groups, clothing styles, and clothing items. There are three outcomes due to the aim of this study, 1. In age group classification, every age groups preferred casual style. Especially, young/young adults preferred mix match styles with various designs. Distinctly, some of missy group preferred fashion trend and others preferred mature style. Also, the preference of missies/madame`s group is obviously divided into two groups which pursues fashion trend and not. 2. In clothing style classification, casual styles such as mini-skirts, hot pants, tight t-shirts, are mostly in tight silhouette. Also, the main colors are indigo-blue, white, black and point color, which are vivid tone and fluorescent colors. The characteristics of sport casual style contribute the upper garment and the lower garment, which forms a set. Classic styles are divided into two groups of typical formal dress and traditional Qipao dress. The colors of feminine style and textile printing are more sumptuous than other styles. 3. In clothing items classification, the points of the upper garments is the construction of designs, textile printing, ornament with beads, embroidery, and ribbon etc., exposed back. The lower garments like hot pants and mini-skirts are made of jeans. The cargo pants that is made of jean, cotton, luster textile. Also, one-piece dress has the characteristics of tiered and irregular hem line.

Multiple occurrence of recurrent nodular fasciitis after surgical extirpation: masquarding as in-transit metastasis of sarcomatous presentation

( Kyung-nam Bae ),( Kihyuk Shin ),( Woo-il Kim ),( Min-young Yang ),( Won-ku Lee ),( Gun-wook Kim ),( Hyun-chang Ko ),( Byung-soo Kim ),( Moon-bum Kim ),( Hoon-soo Kim ) 대한피부과학회 2019 대한피부과학회 학술발표대회집 Vol.71 No.1

Nodular fasciitis (NF) is a rare benign fibrous tumor related with a proliferative reactive process arising mostly from the muscular fascia or deep subcutaneous region. It distinctively appeared as solitary nodule in young-aged patient with rapid growth, which gives its other name as pseudosarcomatous fibromatosis. A 16-year old boy visited our clinic for the palpable mass on the left shoulder. The initial lesion had already been partially removed by the skin biopsy at local clinic. The biopsy specimen showed only fragments of fibrous mass consisting of collagenous stroma with spindle-shaped cells, but no atypia or mitotic figure. Surgical excision was performed, of which the surgical specimen showed invasion of spindle shaped cells involving subcutaneous layer interlacing with conspicious collagenous fiborus stroma without malignant features. After 3 months, two nodules reappeared near the operation sites and the following biopsy results showed the same as before. We decided to observe the remaining lesions and there had been no significant changes for 5 months. Multiple lesional occurrence is as quite uncommon feature of NF as the recurrence after surgical treatment. Herein, we report a rare case of multiple recurrence of NF after surgical extirpation, which presented with in-transit metastasis of sarcoma-like feature.

간암 환자에 합병된 Citrobacter braakii 패혈증 1례 보고

이해미,배성하,이수남,이정우,신아영,류시영,이수연,윤문희,한선영,한남익,이영석,유진홍 대한감염학회 2010 감염과 화학요법 Vol.42 No.3

Citrobacter species is a gram-negative bacilli that can cause opportunistic infections in immunocompromised hosts. Citrobacter braakii refers to the genomospecies 6 of the Citrobacter freundii complex. There are no detailed studies on infections caused by this newly identified specific genetic species in Korea. We herein report a case of a patient with hepatocellular carcinoma who, after undergoing transcatheter arterial chemoembolization, developed biloma which later progressed to C.braakii sepsis and did not respond to treatment. To our knowledge, this is the first reported case in Korea on C. braakii infection resulting in septic shock in a patient with malignancy in Korea.

활석을 이용한 사포나이트의 수열합성

배인국,장영남,채수천,류경원,최상훈 한국광물학회 2003 광물과 암석 (J.Miner.Soc.Korea) Vol.16 No.2

삼팔면체형의 스멕타이트계 사포나이트(saponite)를 천연 광물질인 활석을 이용하여 수열법에 의해 합성하였다. 출발물질은 활석에 Na₂CO₃를 첨가하여 공기중에서 800℃로 가열한 후, 화학양론적 조성에 맞게 Al(No₃)₃·9H₂O 및 Mg(No₃)₂·6H₂O 금속염 수용액을 첨가하였고, pH는 7∼12 범위 내로 NH₄OH 수용액에 의해 조절하여 제조하였다. 수열반응 조건은 약 1리터의 수열반응 용기에서 230 ℃, 압력은 25∼75 kgf/㎠의 범위 내에서 10∼60시간이었다. 실험결과, 반응온도 및 회전속도를 230℃와 180 rpm으로 고정시킨 수열조건 하에서 반응시간, 반응압력, pH 조건을 각각 40시간, 25 kgf/㎠, 약 10으로 하였을 때, 그리고, 화학조성을 화학양론적 조성에 필요한 Na₂O의 양보다 200% 과량 추가하였을 때, 양호한 사포나이트가 합성되었다. 또한 압력을 75 kgf/㎠까지 증가시켜도 결정도에 미치는 영향은 미미하였으며, 반응시간이 길수록 더 좋은 결정도를 나타냈다. Saponite was synthesized from talc by hydrothermal method. The starting material was prepared by adding Al(N0₃)₃·9H₂0 and Mg(N₃)₂·6H₂O solution to the talc powder, which was previously activated in air at 800℃ together with Na₂C0₃. The alkalinity of the solution was controlled by NH₄0H solution. The autoclaving was carried out in the closed stainless steel vessel (about 1 liter) for 40 hours under the pressure of 25 ㎏f/㎠ at 230℃. The characterization of the reaction product shows that saponite was crystallized successfully. After the experimental results, pressure was not sensitive parameter in the range of 25-75 ㎏f/㎠, but longer reaction time results in better crystallinity.