• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.980-983
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• 2002

We investigated the effect of quinolate metal complex layer as an electron injection layer on the performance of OLEDs and optimized the device efficiency by varying from 0.5 to 10nm thickness of Liq layer. OLED with a structure of indium tin oxide/$\alpha$-napthylphenylbiphenyl(NPB,40nm)/tris-(8-hydroxyquinoline)aluminum(Alq3, 50nm)/Aluminum(150nm) were fabricated in sequence. The device with 1nm Quinolate metal complex layer showed significant enhancement of the device performance.

• 한국진공학회지
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• 제7권2호
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• pp.135-140
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• 1998

고온($350^{\circ}C$)에서 polyimide위에 증착한 Cu의 초기성장 과정과 Cu/polyimide계면에서 의 반응물 형성에 관하여 XPS를 이용하여 관찰하였다. Polyimide 위에 고온 중에서의 Cu 증착시, 상온에서와는 달리 초기에는 Cu-C-N complex가 먼저 형성되고, 다음에 Cu-N-O complex가 주가 되어 Cu/Polyimide 계면을 형성하고, Cu의 증착두께가 증가함에 따라 Cu 산화물에서 서서히 metallic Cu로 성장하는 것을 볼 수 있었다. 그리고 반응물 형성 관점에 서, Cu 고온 증착시에 형성된 Cu/polyimide의 계면이 상온에서 이루어진 계면보다 상당히 예리함을 볼 수 있었다.

• Toxicological Research
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• 제31권2호
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• pp.157-163
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• 2015

Nanotechnology has advanced at an extremely rapid pace over the past several years in numerous fields of research. However, the uptake of nanoparticles (NPs) into the body after administration through various routes may pose a risk to human health. In this study, we investigated the potential ocular toxicity of 20-nm, negatively- charged zinc oxide (ZnO) NPs in rats using micro-computed tomography (micro-CT) and histopathological assessment. Animals were divided into four groups as control group, ZnO NPs treatment group (500 mg/kg/day), control recovery group, and ZnO NPs treatment and recovery group. Ocular samples were prepared from animals treated for 90 days (10 males and 10 females, respectively) and from recovery animals (5 males and 5 females, respectively) sacrificed at 14 days after final treatment and were compared to age-matched control animals. Micro-CT analyses represented the deposition and distribution of foreign materials in the eyes of rats treated with ZnO NPs, whereas control animals showed no such findings. X-ray fluorescence spectrometry and energy dispersive spectrometry showed the intraocular foreign materials as zinc in treated rats, whereas control animals showed no zinc signal. Histopathological examination revealed the retinopathy in the eyes of rats treated with ZnO NPs. Neuronal nuclei expression was decreased in neurons of the ganglion cell layer of animals treated with ZnO NPs compared to the control group. Taken together, treatment with 20-nm, negatively-charged ZnO NPs increased retinopathy, associated with local distribution of them in ocular lesions.

• Journal of Pharmaceutical Investigation
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• 제21권3호
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• pp.149-153
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• 1991

Polyethylene oxide (PEO)-polymethacrylic acid (PMAA) interpenetrating polymer networks (IPN) were synthesized via radical polymerization of PMAA and simultaneous crosslinking of PEO using triisocyanate. The equilibrium swelling of PEO-PMAA IPN was determined at different pHs. The swelling of PEO-PMAA IPN, ranged from 20% to 90%, was more sensitive than that of homo polymer PMAA gel This is probably due to protonation and deprotonation of the PMAA network and interpolymer complex formation between PEO and PMAA. Several model drugs were loaded into the IPN matrices and the release mechanisms were investigated. The release of nonionizable drugs such as ftorafur and prednisolone was controlled by swelling of the matrices. However, he release of propranolol, positively charged drug, was more affected by the ionic interaction between the drug and PMAA newtork, and the interpolymer complexation.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1650-1653
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• 2007

We demonstrate fluorescent green organic lightemitting diodes employing a rhenium oxide ($ReO_3$)-doped N,N-diphenyl-N,N'-bis(1,1'-biphenyl)-4,4'-diamine (NPB) hole transporting layer (HTL). The devices exhibit significantly reduced driving voltages as well as prolonged lifetime. Details of $ReO_3$ doping effects are described in terms of charge transfer complex and stabilization of HTL morphology.

• 한국정밀공학회지
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• 제14권7호
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• pp.22-28
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• 1997

In this paper, We have studied internal quality incluiding chemical compositions, microscopic structure and nonmetalic inclusion of test material. We have analyzed dynamic characteristics of cutting resistence and compared chip treatment of the test material. In analyzing internal quality, all of the test material have typical ferrite+pearlite structure. But, nonmetallic inclusion has oxide and sulfide inclusion has oxide and sulfide inclusion in medium carbon steel, mainly sulfide inclusion is existed in S-free cutting steel. In Ca+S-free cutting steel, calcium aluminate and sulfide complex inclusion, had low-melting point, as deformation of sulfide and oxide inclusion is existed. Machining characteristics, cutting resistence is maximum in medium carbon steel. Chip treatement are excellent in S-free cutting steel, similar to the Ca+S free cutting steel and medium carbon steel.

• 자원리싸이클링
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• 제9권4호
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• pp.16-27
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• 2000

본 연구에서는 기능성 자성재료의 원료분말을 분무배소법에 의해 제조하기 위하여 원료 용액을 효율적으로 미립화시킨 후 반응로 내로 분무시킬 수 있으며, 반응로 내부는 균일한 열분포를 이루어 열분해반응이 완전하게 진행 될 뿐만 아니라, 생성된 분말을 cyclone 및 bag filter 등의 포짐장치에서 효율적으로 포집할 수 있으며, 유해 생성가스를 청정시킬 수 있는 장치까지 포함하는 개선된 분무배소로 system을 제작하였다. 또한 본 연구에서는 불순물들을 다량 함유하고 있는 mill scale 및 ferro-Mirr을 산용액에 용해 시킨 복합 산용액의 pH를 4정도로 조절하여 용액 내에 존재하는 $SiO_2$, P 및 Al 등의 불순물들을 약 20ppm 이하로 감소시킴으로써 mill scale 및 ferro-Mn의 분무열분해를 위한 원료로의 재활용 가능성을 확인하였다. 원료용액인 정제된 복합 산용액을 nozzle을 통하여 분무배소로 내부로분무시킴으로써 Fe-Mn 계의 복합 산화물 분말을 제조하였으며, 반응온도, 원료용액 및 공기의 유입속도, nozzle tip 크기 및 원료용액의 농도 등의 주요 반응조건의 변화에 따른 생성분말의 특성 변화를 파악하였다. 생성된 분말들의 형상은 대부분의 반응조건에서 구형을 나타내고 있었으며, 조성 및 입도분포가 매우 균일하게 혼합된 형태로 나타남으로써 본 연구에 의해 제작된 분무배소로 system의 우수성을 확인할 수 있었다. 한편 본 반응조건 하에서 생성된 분말들의 결정입도가 대부분 약 100nm 이하으 초미립상태이면서 형상 및 입도분포가 매우 균일하다는 사실은 본 연구에서 제작한 분무배소, system을 이용함에 의해 Fe, Mn, Ni, Cu 및 회토류계 염화물로부터 초미립의 산화를 분말을 제조할 수 있을 뿐만 아니라, 반응분위기의 변화에 따라 초미립 순금속분말의 제조도 충분히 가능할 것으로 사료된다.

• 한국전기전자재료학회논문지
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• 제28권6호
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• pp.351-359
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• 2015

Next-generation displays should be transparent and flexible as well as having high resolution and frame number. The main factor for active matrix organic light emitting diode and next-generation displays is the development of TFTs (thin-film transistors) with high mobility and large area uniformity. The TFTs used for transparent displays are mainly oxide TFT that has oxide semiconductor as channel layer. Zinc-oxide based substances such as indium-gallium-zinc-oxide has attracted attention in the display industry. In this paper, the mobility improvement of low cost oxide TFT is studied for fast operating next-generation displays by overcoming disadvantages of amorphous silicon TFT that has low mobility and poly silicon TFT that requires expensive equipment for complex process and doping process.

• Nuclear Engineering and Technology
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• 제46권6호
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• pp.857-862
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• 2014

Mechanical alloying under various gas atmospheres such as Ar, an Ar-$H_2$ mixture, and He gases were carried out, and its effects on the powder properties, microstructure and mechanical properties of ODS ferritic steels were investigated. Hot isostatic pressing and hot rolling processes were employed to consolidate the ODS steel plates. While the mechanical alloyed powder in He had a high oxygen concentration, a milling in Ar showed fine particle diameters with comparably low oxygen concentration. The microstructural observation revealed that low oxygen concentration contributed to the formation of fine grains and homogeneous oxide particle distribution by the Y-Ti-O complex oxides. A milling in Ar was sufficient to lower the oxygen concentration, and this led a high tensile strength and fracture elongation at a high temperature. It is concluded that the mechanical alloying atmosphere affects oxygen concentration as well as powder particle properties. This leads to a homogeneous grain and oxide particle distribution with excellent creep strength at high temperature.

• 한국전기전자재료학회논문지
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• 제13권10호
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• pp.822-827
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• 2000

The Si-SiO$_2$interface trap and nitride bulk trap distribution of SONOSFET(polysilicon-oxide-nitride-oxide-semiconductor field effect transistor) NVSM (nonvolatile semiconductor memory) cell is investigated by single junction charge pumping method. The device was fabricated by 0.35㎛ standard logic fabrication process including the ONO stack dielectrics. The thickness of ONO dielectricis are 24$\AA$ for tunnel oxide, 74 $\AA$ for nitride and 25 $\AA$ for blocking oxide, respectively. By the use of single junction charge pumping method, the lateral profiles of both interface and memory traps can be calculated directly from experimental charge pumping results without complex numerical simulation. The interface traps were almost uniformly distributed over the whole channel region and its maximum value was 7.97$\times$10$\^$10/㎠. The memory traps were uniformly distributed in the nitride layer and its maximum value was 1.04$\times$10$\^$19/㎤. The degradation characteristics of SONOSFET with write/erase cycling also were investigated.