입내 분산형 Al₂O₃/Ag 나노복합체의 제조와 특성

천승호,한인섭,히데오 아와지,Cheon, Sung-Ho,Han, In-Sub,Awaji, Hideo 한국세라믹학회 2007 한국세라믹학회지 Vol.44 No.4

Alumina/silver ($Al_2O_3/Ag$) nanocomposites with Ag content up to 9 vol% were prepared from nanopowder by soaking method using ${\gamma}-Al_2O_3$ of needle type and spark plasma sintering (SPS). The mechanical properties of specimens were investigated three-point flexural strength and toughness as a function of the Ag contents. The maximum flexural strength of the alumina/silver nanocomposite was 850 MPa for the 1 vol% composite, and also higher than monolith alumina as about 800 MPa at 3, 5, and 7 vol% Ag contents. Fracture toughness by single edged V-notch beam (SEVNB) was $4.05MPa{\cdot}m^{1/2}$ for the 3 vol% composite and maintained about $4.00MPa{\cdot}m^{1/2}$ at 5, and 7 vol% Ag content. Microstructure of fracture surface for each fracture specimens was observed. Due to the inhibition effect of alumina grain growth, the average grain size of nanocomposites depends on the content of Ag nano particles. The fracture morphology of nanocomposite with dislocation (sub-grain boundary) by silver nano-particles of second phases in the alumina matrix also showed transgranular fracture-mode compare with intergranular of monolith alumina. Thermal conductivity of specimens at room temperature was about 40 W/mK for the 1 vol% Ag content.

수술과 항암치료 후 종양표지자 검사의 상승으로 복막 가성점액종의 재발을 확인한 1례

한인섭,송근암,김광하,이봉은,백동훈,이성준,이문원,한성용,In Sub Han,Geun Am Song,Kwang Ha Kim,Bong Eun Lee,Dong Hoon Baek,Seong Jun Lee,Moon Won Lee,Sung Yong Han 대한소화기암연구학회 2016 Journal of digestive cancer reports Vol.4 No.1

Pseudomyxoma peritonei (PMP) is a rare clinical syndrome characterized by profuse jelatinous materials in the abdominal cavity and pelvis with mucinous implants on the peritoneal surface. There are some studies for serum tumor markers, including carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9) and carbohydrate antigen 125 (CA125), to assess the risk of recurrence following cytoreductive surgery and intraperitoneal chemotherapy. However, rare cases were reported about recurrence with increasing serum CEA levels. Herein, we report a case of recurrence of PMP according to serially elevated serum CEA.

액상 Ni/Si/Co 침투에 의한 반응결합 TiC 복합체의 치밀화

한인섭,우상국,배강,홍기석,서두원,정윤중,Han, In-Sub,Woo, Sang-Kuk,Bai, Kang,Hong, Ki-Suk,Seo, Doo-Won,Chung, Yoon-Jung 한국세라믹학회 1998 한국세라믹학회지 Vol.35 No.10

The reaction-bonded TiC-Ni/Si/Co composites were prepared by the melt infiltration of Co, Si, and Ni me-tal into the TiC preforms. The miocrostructure reaction composition and mechanical properties were in-vestigated. In the case of the melt infiltrated with Co and Ni TiC grain shape was changed from angular to spherical shape with the average grain size of ∼5$\mu\textrm{m}$. In the case of the melt infiltrated with Co/Si or Ni/Si, Si was reacted with TiC particles and formed SiC particles. The bending strength of both specimens which have atomic ratio of 3 were 710 MPa and 515 MPa respectively. In the case of the melt infiltrated with Ni/Si/Co,. nonstoichiometric TiC was formed and its bending strength decreased to 420 MPa.

진공 압출성형 및 래밍성형 공정에 의한 탄화규소 캔들 필터 제조 및 특성 (II)

한인섭,서두원,김세영,홍기석,우상국,김영욱,Han, In-Sub,Seo, Doo-Won,Kim, Se-Young,Hong, Ki-Seog,Woo, Sang-Kuk,Kim, Young-Wook 한국세라믹학회 2010 한국세라믹학회지 Vol.47 No.6

Porous SiC candle filter preforms were fabricated by extrusion and ramming process. To fabricate SiC candle filter preform, commercially available F180 mesh ($85\;{\mu}m$) $\alpha$-SiC powder and $44\;{\mu}m$ mullite, $CaCO_3$ powder were used as the starting materials. The candle type preforms were fabricated by vacuum extrusion and ramming process, and sintered at $1400^{\circ}C$ 2 h in air atmosphere. Corrosion test of the sintered candle filter specimens as forming method was performed at $600^{\circ}C$ for 2,400 h in simulated IGCC syngas atmosphere. The effect of forming method on mechanical properties, pore distribution, microstructure and crystalline phase was investigated.

초음파 분무 열분해법에 의해 성장된 ZnO 박막의 특성에 미치는 Li 첨가의 영향

한인섭,박일규,Han, In Sub,Park, Il-Kyu 한국재료학회 2018 한국재료학회지 Vol.28 No.2

Li-incorporated ZnO thin films were deposited by using ultrasonic-assisted spray pyrolysis deposition (SPD) system. To investigate the effect of Li-incorporation on the performance of ZnO thin films, the structural, electrical, and optical properites of the ZnO thin films were analyzed by means of X-ray diffraction (XRD), field-emssion scanning electron microscopy (FE-SEM), Hall effect measurement, and UV-Vis spectrophotometry with variation of the Li concentraion in the ZnO sources. Without incorporation of Li element, the ZnO surface showed large spiral domains. As the Li content increases, the size of spiral domains decreased gradually, and finally formed mixed small grain and one-dimensional nanorod-like structures on the surface. This morphological evolution was explained based on an anti-surfactant effect of Li atoms on the ZnO growth surface. In addition, the Li-incorporation changed the optical and electrical properties of the ZnO thin films by modifying the crystalline defect structures by doping effects.

성형공정(成形工程)과 원료입도(原料粒度)가 다공성(多孔性) 탄화규소(炭火硅素) 세라믹 캔들 필터 특성(特性)에 미치는 영향(影響)

한인섭,서두원,홍기석,우상국,Han, In-Sub,Seo, Doo-Won,Hong, Ki-Seog,Woo, Sang-Kuk 한국자원리싸이클링학회 2010 資源 리싸이클링 Vol.19 No.5

석탄가스화 복합발전 시스템의 집진설비용 다공성 탄화수소 캔들 필터 제조를 위해 래밍성형과 진공 압출성형 공정에 외해 캔들필터 성형체를 제조하였다. 다양한 입도를 갖는 탄화규소 분말을 출발원료로 하였으며, 비점토계 무기 소결조제로 뮬라이트와 칼슘 카보네이트 분말을 사용하였다. 래밍성형과 진공 압출성형에 의한 캔들 필터 성형체들은 대기 분위기 $1400^{\circ}C$에서 2시간 소성하여 제조하였다. 캔들 필터 성형공정과 출발원료 입도가 소결된 다공성 캔들 필터 지지층의 기공율, 밀도, 강도 (굽힘강도, 압축강도)와 미세구조에 미치는 영향을 조사하였다. 래밍성형 공정에 외한 제조원 다공성 탄화규소 캔들 필터 소결체가 압출성형된 필터에 비해 높은 밀도 및 강도를 나타내고 있었으며, 그 최고 값은 각각 $2.0\;g/cm^3$과 45 MPa이었다. 한편 캔들 필터 지지층의 장기 내식성 평가 예측을 위하여 소결된 시편에 대해 석탄가스화 복합발전 $600^{\circ}C$의 모사 합성가스 분위기에서 2400시간 부식실험을 수행하였다. To fabricate porous SiC candle filter for filtration facility of the IGCC system, the candle type filter preforms were fabricated by ramming and vacuum extrusion process. A commercially available ${\alpha}$-SiC powders with various particle size were used as starting raw materials, and $44\;{\mu}m$ mullite, $CaCO_3$ powder were used as non-clay based inorganic sintering additive. The candle typed preforms by ramming process and vacuum extrusion were sintered at $1400^{\circ}C$ for 2h in air atmosphere. The effect of forming method and particle size of filter matrix on porosity, density, strength (flexural and compressive strength) and microstructure of the sintered porous SiC candle tilters were investigated. The sintered porous SiC filters which were fabricated by ramming process have more higher density and strength than extruded filter in same particle size of the matrix, and its maximum density and 3-point bending strength were $2.00\;g/cm^3$ and 45 MPa, respectively. Also, corrosion test of the sintered candle filter specimens by different forming method was performed at $600^{\circ}C$ for 2400h using IGCC syngas atmosphere for estimation of long-term reliability of the candle filter matrix.

초음파 분무 열분해법을 이용한 구리산화물 박막 성장

한인섭,박일규,Han, In Sub,Park, Il-Kyu 한국재료학회 2018 한국재료학회지 Vol.28 No.9

Copper oxide thin films are deposited using an ultrasonic-assisted spray pyrolysis deposition (SPD) system. To investigate the effect of substrate temperature and incorporation of a chelating agent on the growth of copper oxide thin films, the structural and optical properites of the copper oxide thin films are analyzed by X-ray diffraction (XRD), field-emssion scanning electron microscopy (FE-SEM), and UV-Vis spectrophotometry. At a temperature of less than $350^{\circ}C$, three-dimensional structures consisting of cube-shaped $Cu_2O$ are formed, while spherical small particles of the CuO phase are formed at a temperature higher than $400^{\circ}C$ due to a Volmer-Weber growth mode on the silicon substrate. As a chelating agent was added to the source solutions, two-dimensional $Cu_2O$ thin films are preferentially deposited at a temperature less than $300^{\circ}C$, and the CuO thin film is formed even at a temperature less than $350^{\circ}C$. Therefore the structure and crystalline phase of the copper oxide is shown to be controllable.

초음파 분무 열분해법에 의한 ZnO 나노구조 성장시 Leidenfrost 효과에 의한 성장 거동 변화

한인섭,박일규,Han, In Sub,Park, Il-Kyu 한국재료학회 2017 한국재료학회지 Vol.27 No.11

We investigated a Leidenfrost effect in the growth of ZnO nanostructures on silicon substrates by ultrasonic-assisted spray pyrolysis deposition(SPD). Structural and optical properties of the ZnO nanostructures grown by varying the growth parameters, such as substrate temperature, source concentration, and suction rate of the mist in the chambers, were investigated using field-emission scanning electron microscopy, X-ray diffraction, and photoluminescence spectrum analysis. Structural investigations of the ZnO nanostructures showed abnormal evolution of the morphologies with variation of the substrate temperatures. The shape of the ZnO nanostructures transformed from nanoplate, nanorod, nanopencil, and nanoprism shapes with increasing of the substrate temperature from 250 to $450^{\circ}C$; these shapes were significantly different from those seen for the conventional growth mechanisms in SPD. The observed growth behavior showed that a Leidenfrost effect dominantly affected the growth mechanism of the ZnO nanostructures.

ZnO buffer 층을 이용한 초음파 분무열분해 ZnO 박막 증착

한인섭,박일규,Han, In Sub,Park, Il-Kyu 한국재료학회 2017 한국재료학회지 Vol.27 No.8

We investigated the effect of ZnO buffer layer on the formation of ZnO thin film by ultrasonic assisted spray pyrolysis deposition. ZnO buffer layer was formed by wet solution method, which was repeated several times. Structural and optical properties of the ZnO thin films deposited on the ZnO buffer layers with various cycles and at various temperatures were investigated by field-emission scanning electron microscopy, X-ray diffraction, and photoluminescence spectrum analysis. The structural investigations showed that three-dimensional island shaped ZnO was formed on the bare Si substrate without buffer layers, while two-dimensional ZnO thin film was deposited on the ZnO buffer layers. In addition, structural and optical investigations showed that the crystalline quality of ZnO thin film was improved by introducing the buffer layers. This improvement was attributed to the modulation of the surface energy of the Si surface by the ZnO buffer layer, which finally resulted in a modification of the growth mode from three to two-dimensional.

강화 섬유의 분산도가 SiC_f/SiC 복합소재의 기계적 강도에 미치는 영향

최지범,김수현,이슬희,한인섭,방형준,김세영,성영훈,Ji Beom Choi,Soo-Hyun Kim,Seulhee Lee,In-Sub Han,Hyung-Joon Bang,Seyoung Kim,Young-Hoon Seong 한국복합재료학회 2023 Composites research Vol.36 No.3

This paper investigates the impact of fiber dispersion on the internal structure and mechanical strength of SiC_f/SiC composites manufactured using spread SiC fibers. The fiber volume ratio of the specimen to which spread SiC fiber was applied decreased by 9%p compared to the non-spread specimen, and the resin slurry impregnated between the fibers more smoothly, resulting in minimal matrix porosity. In order to compare the fiber dispersion of each specimen, a method was proposed to quantify and evaluate the separation distance between fibers in composite materials. The results showed that the distance between fibers in the spread specimen increased by 2.23 ㎛ compared to the non-spread specimen, with a significant 42.6% increase in the distance between fiber surfaces. Furthermore, the 3pt bending test demonstrated a 49.3% higher flexural strength in the spread specimen, accompanied by a more uniform deviation in test data. These findings highlight the significant influence of SiC fiber dispersion on achieving uniform densification of the SiC_f/SiC matrix and increasing mechanical strength.