• 대한화학회지
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• 제38권4호
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• pp.319-327
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• 1994

질소원자를 네 개 또는 다섯 개 가지는 트리에틸렌테트라아민과 테트라에틸렌펜타아민에 살리실알데히드를 각각 반응시켜 황갈색 액체상의 여섯자리 배위자리를 가지는 새로운 시프 염기 리간드인 비스(살리실알데히드)-트리에틸렌테트라아민(BSTT)과 일곱자리 시프 염기인 비스(살리실알데히드)-테트라에틸렌펜타아민(BSTP)을 합성하고, 다시 이들 액체상의 시프 염기에 아세트산과 진한 염산을 가하여, pH4.0의 특정한 농도하에서 연노란색의 염산염 시프 염기들의 결정을 얻었다. 또한 이들 시프 염기 리간드와 구리(Ⅱ)를 반응시켜 새로운 시프 염기-구리(Ⅱ)착물을 합성하여 여러가지 물리적 및 화학적 성질에서부터 가능한 이들 화합물의 구조를 제안하였다.

• ETRI Journal
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• 제11권4호
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• pp.84-97
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• 1989

The influence of Zn, Si and Te diffusion on the interdiffusion in $GaAs-Ga_1_-xIN_xAs_1__yP_y$and InP$Ga_1__xIn_xAs_1__yP_y$ heterostructures was studied. The heterostructures were grown by liquid phase epitaxy, and the impurity diffusion into the heterostructures was carried out using metal compound or element sources. The extent of interdiffusion for both group III and V atoms was observed by depth profiling of matrix elements with secondary ion mass spectrometry and Auger electron spectroscopy. Selective enhancement of cation interdiffusion was observed by the concurrent Zn diffusion in both the GaAs based-and InP based-crystals. In contrast to the Zn diffusion, the Si diffusion in the GaAs based-crystal and the Te diffusion in the InP based-crystal enhanced both cation and anion interdiffusion to the same extent. A kick-out mechanism is proposed to explain the selective enhancement of the cation interdiffusion due to Zn, and a single vacancy mechanism is proposed for the interdiffusion due to Si and Te.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 기술심포지움 논문집
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• pp.103-105
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• 2003

COG (Chip on Glass) technology using solder bump reflow has been investigated to attach IC chip directly on glass substrate of LCD panel. As It chip and LCD panel have to be heated to reflow temperature of the so]der bumps for COG bonding, it is necessary to use low-temperature solders to prevent the damage of liquid crystals of LCD panel. In this study, using the Sn-52In solder bumps of $40{\mu}m$ pitch size, solder joints between Si chip and glass substrate were made at temperature below $150^{\circ}C$. The contact resistance of the solder joint was $8.58m\Omega$, which was much lower than that of the joint made using the conventional ACF bonding technique. The Sn-52In solder joints with underfill showed excellent reliability at a hot humid environment.

• 한국결정성장학회지
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• 제19권5호
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• pp.215-222
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• 2009

Many concepts of external magnetic field applications in crystal growth processes have been developed to control melt convection, impurity content and growing interface shape. Especially, travelling magnetic fields (TMF) are of certain advantages. However, strong shielding effects appear when the TMF coils are placed outside the growth vessel. To achieve a solution of industrial relevance within the framework of the $KRISTMAG^{(R)}$ project inner heater-magnet modules(HMM) for simultaneous generation of temperature and magnetic field have been developed. At the same time, as the temperature is controlled as usual, e.g. by DC, the characteristics of the magnetic field can be adjusted via frequency, phase shift of the alternating current (AC) and by changing the amplitude via the AC/DC ratio. Global modelling and dummy measurements were used to optimize and validate the HMM configuration and process parameters. GaAs and Ge single crystals with improved parameters were grown in HMM-equipped industrial liquid encapsulated Czochralski (LEC) puller and commercial vertical gradient freeze (VGF) furnace, respectively. The vapour pressure controlled Czochralski (VCz) variant without boric oxide encapsulation was used to study the movement of floating particles by the TMF-driven vortices.

• 한국전기전자재료학회논문지
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• 제16권6호
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• pp.510-514
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• 2003

We have studied the alignment of liquid crystals (LCs) on homeotropic polymeric surface that is scanned using an atomic force microscope (AFM) tip by optical polarizing microscopy and computer simulation. The scanned areas on one substrate are 5 $\mu\textrm{m}$ ${\times}$ 5 $\mu\textrm{m}$, 10 $\mu\textrm{m}$ ${\times}$ 10 $\mu\textrm{m}$, and 20 $\mu\textrm{m}$ ${\times}$ 20 $\mu\textrm{m}$ and this substrate is assembled to another substrate coated. with homeotropic polymer. The fabricated micro-LC cell using two substrates does not show any hysteresis and disclination lines inside the nano-rubbing areas, while changing voltage up and down. This indicates that the pretilt angle exists in the areas, thereby forming a hybrid LC configuration. From the experimental and computer simulation results, we can understand that the AFM rubbing clearly changes surface status of homeotropic alignment layer and causes the pretilt angle to an initial scanning direction.

• Progress in Superconductivity
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• 제3권1호
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• pp.5-12
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• 2001

Our experimental research focuses on manipulating pinning deflects to alter the phase diagram of vortex matter, creating new vortex phases. Vortex matter offers a unique opportunity for creating and studying these novel phase transitions through precise control of thermal, pinning and elastic energies. The vortex melting transition in untwinned YB $a_2$C $u_3$ $O_{7-}$ $\delta$/ crystals is investigated in the presence of disorder induced by particle irradiation. We focus on the low disorder regime, where a glassy state and a lattice state can be realized in the same phase diagram. We follow the evolution of the first order vortex melting transition line into a continuous transition line as disorder is increased by irradiation. The transformation is marked by an upward shift in the lower critical point on the melting line. With columnar deflects induced by heavy ion irradiation, we find a second order Bose glass transition line separating the vortex liquid from a Bose glass below the lower critical point. Furthermore, we find an upper threshold of columnar defect concentration beyond which the lower critical point and the first order melting line disappear together. With point deflect clusters induced by proton irradiation, we find evidence for a continuous thermodynamic transition below the lower critical point..

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1527-1530
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• 2009

A LCoS micro-display using polymer dispersed liquid crystals (PDLCs) for light switching layer was fabricated. The Si backplane of SVGA ($800{\times}600$) with a pixel size of $14{\times}14mm^2$ was prepared by a $0.35{\mu}m$ 18V CMOS process. PDLCs were filled in the gap between backplane and ITO glass by conventional vacuum filling method. The prepared panels were driven by a field sequential color (FSC) scheme at the frequency of 180Hz and were successful in modulating LED lights to show projection images. The preparation and performance of PDLC-LCoS are presented.

• 한국결정성장학회지
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• 제2권2호
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• pp.53-62
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• 1992

SOI구조 형성을 위항 대용융 재결정(ZMR) 공정에서 타원형의 반사경을 기울여 빔강도분포를 인위적으로 변화시켜 실리콘 박막을 재결정시켰다. 비대칭 선형가열 효과를 해석하기 위하여 전산모사를 행하여 응고계면 근처에서의 온도분포와 열구배 변화를 조사하였다. 상부집속열원의 경사각이 증가할수록 액상의 과냉도와 실리콘 박막내의 결함열 간격은 증가하였다. 주된 결함은 연속적인 아결정립계였고 결함밀도가 낮은 경우는 isolated threading dislocations만이 관찰되었다. 단면 TEM과 박막 XRD 분석결과 실리콘 박막은 (100) 집합조직을 갖는 단결정 박막으로 재결정되었음을 확인할 수 있었다.

• 자원환경지질
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• 제28권5호
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• pp.445-454
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• 1995

The petrochemical data of the porphyritic granites of Cretaceous age in the Yonghwa-Seolcheon area show the trend of subalkaline magma, calc-alkaline magma, I-type granitoid and magnetite series. This granite is the relevant igneous rock of gold-silver mineralization in this mining district Fluid inclusions have been studied in phenocryst quartz from the Cretaceous porphyritic granite. Three main types of fluid inclusion were found : liquid-rich inclusion(I type), gas-rich inclusion(II type) and solid-bearing inclusions(III-A, III-B). The solid-bearing inclusions(III-A,B) represent the earliest trapped fluids. They have salinities between 41.0 and 67.5 wt% equivalent to NaCl. These are high saline inclusions containing NaCl and KCl daughter crystals. Homogenization temperature inferred from the fluid inclusion study ranges from 650 to $75^{\circ}C$ Type I and II inclusions were observed within the same fracture. This cause for these differences in degree of filling is evidence of boiling. Salinities of type I and II inclusions range from 9.87 wt% to 15.29 wt%, from 8.40 wt% to 14.64 wt% NaCl equivalent, respectively.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.115-116
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• 2023

This study aims to investigate and improve the carbon dioxide sequestration capability and the mechanical properties of non-hydraulic low calcium silicate cement especially designed for CO₂ reaction and ordinary Portland cement subjected to the carbonation curing facilitating pH swing method. Nitric acid (HNO₃) was utilized as an liquid for the mixing of cement paste to enhance the initial dissolution of Ca ions from the cements by promoting low pH environment and prevent the direct precipitation of Ca with the anion, owing to the high solubility of Ca(NO₃)₂ in water. The results presented that the higher the concentration of HNO₃, the higher the compressive strength and CO₂ sequestration (until 0.1 M). Ca dissolution caused by the harsh acid attack onto the anhydrous cement particle lead to the higher carbonation reaction degree, forming abundant CaCO₃ crystals after the reaction. However, cement paste mixed with excessively high concentration of HNO₃ presented deterioration due to the too harsh pH environment and abundant NO₃- ions which are known to retard the reaction of cement.