• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 춘계학술발표대회 논문집
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• pp.265-268
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• 2005

A new method for measurement of the pore size in a nanohoneycomb structure using atomic force microscopy (AFM) was proposed. Porous type anodic aluminum oxide (AAO) was fabricated as a nanohoneycomb structure to measure the pore size. For measuring pore sizes from AFM images, a criterion was set in porous type AAO. The pore sizes from AFM images were compared with those from SEM images, and the results showed good agreement. The relationship between the pore size and widening time was found to be linear in the range of this study. It was understood as the synchronized effects of the impurity gradient in outer oxide of AAO, mechanical packing and mass transfer increase.

• Macromolecular Research
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• 제9권1호
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• pp.1-19
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• 2001

Poly(p-phenylene pyromellitimide) and poly(4,4'-biphenylene pyromellitimide) are representatives of fully rod-like polyimides. Their structure and properties in thin films are reviewed. The polymers exhibit some excellent properties such as high molecular packing coefficient, high mechanical modulus, and low thermal expansion coefficient, and low interfacial stress, so that they are very attractive to both industry and academia. However, these polymers are very brittle and thus practically useless. Some chemical modifications to improve such drawback with a little sacrifice of the high modulus are described: i) incorporation of short side groups into the polymer backbone and ii) insertion of proper linkages into the polymer backbone.

• 한국표면공학회지
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• 제34권3호
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• pp.187-194
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• 2001

Galvalume sheet steel was developed recently, and is used widely in several fields. It has and had a good corrosion resistance in open atmosphere, but it has week corrosion resistance in the ambient surroundings of an airtight packing. Therefore, black patina was synthesized on the surface of Galvalume sheet steel. Corrosion by moisture on a Galvalume surface begins from edge of a droplet and proceeds to the center of droplet. It begins mainly on the interdendritic structure instead of dendritic structure. This suggests that corrosion by moisture occurs on the Zn shrinkage hole from rapid air cooling. In addition, the initial corrosion occurs by the local cell and continues by the oxygen concentration cell.

• 전자공학회논문지C
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• 제35C권7호
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• pp.20-29
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• 1998

As the packing density of ICs in recent submicron IC design increases, interconnects gain importance. Because interconnects directly affect on two major components of circuit performance, power dissipation and operating speed, circuit engineers are concerned with the optimal design of interconnects and the aid tool to design them. When circuit models of interconnects are given (including geometry and material information), the analysis process for the given structure is not an easy task, but conversely, it is much more difficult to design an interconnect structure with given circuit characteristics. This paper focuses on the latter process that has not been foucsed on much till now due to the complexity of the problem, and prsents a design aid tool(DATOIS) to synthesize interconnects. this tool stroes the circuit performance parameters for normalized interconnect geometries, and has two oeprational modes:analysis mode and synthesis mode. In the analysis mode, circuit performance parameters are obtained by searching the internal database for a given geometry and interpolates results if necessary . In thesynthesis mode, when a given circuit performance parameter satisfies a set of geometry condition in the database, those geometry structures are printed out.

• 소성∙가공
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• 제19권5호
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• pp.296-304
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• 2010

It is still needed to study the effect of process conditions on the final properties of injection-molded parts for producing precision optical products. Especially, the optical anisotropy, i.e., birefringence, is a significant factor to affect the function of many optical components. In the present study we have focused on the effect of holding and compression processes on the birefringence remaining in the transparent disc by examining the gap-wise distribution of birefringence and extinction angle. As a result, two extra birefringence and extinction peaks near the center in thickness direction showed the effect of holding pressure, which came from the flow in packing stage. However, more uniform birefringence distribution than injection-only cases could be found in injection/compression cases. Depends on the process condition even the flow reversal could be found from the distribution of extinction angle. Finally, graphical representation of optical indicatrix was added for better understanding the final structure of injection-only and injection/compression cases.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.302-305
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• 2007

In recent years, many researches on new storage media with high capacity and information are developing. For manufacture of optical storage with high capacity, the injection molding process is generally used. In order to increase the filling ratio of the injection molding structure, the injection molding process required for high injection pressure, packing pressure and temperature control of the mold. However, conventional injection molding process is difficult to increase the filling ratio using injection master with the range of several nanometers and high aspect ratio. In order to improve and increase filling ratio of nano-structure with high aspect ratio, the active temperature control of injection mold was used. Experimental conditions were used injection pressure, time and temperature. Consequently, by using the peltier device into injection mold, we carried out the efficient and active temperature control of mold at low cost.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
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• pp.13-15
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• 2002

The trench MOSFET structure is characterized by reduced on-resistance due to elimination of $R_{JFET}$ and high packing density. An analytical calculation of Ron as the sum of $R_{ch}$ and $R_{epi}$ has been reported previously for the trench MOSFET structure. However, the accumulation layer resistance may not be neglected for Trench MOSFET especially for a relatively large value of the cell spacing, where a major contribution to Ron comes from Ra as the simulation results in this paper shows.

• Bulletin of the Korean Chemical Society
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• 제4권3호
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• pp.123-127
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• 1983

The crystal structure of metoclopramide, $C_14H_22ClN_3O_2$, has been determined by X-ray diffraction techniques using diffractometer data obtained by the ${\omega}-2{\theta}$ scan technique with Mo $K\alpha$ radiation from a crystal with space group symmetry $P{\overline{1}}$ and unit cell parameters a = 7.500(1), b = 8.707(2), c = 13.292(2) ${\AA}$; ${\alpha}$ = 101.70(2), ${\beta}$ = 81.20(2), and ${\gamma}$ = $114.90(l)^{\circ}$. The sructure was solved by direct methods and refined by full-matrix least-squares to a final R = 0.055 for the 1524 observed reflections. The bent overall-conformation of the molecule seems to be determined mainly by the bifurcated intramolecular hydrogen bond from the amide nitrogen atom to the methoxy oxygen and the amine nitrogen atoms. The crystal packing consists of the hydrogen bonds, ${\pi}-{\pi}$ interaction and hydrophobic interaction.

• Journal of Electrochemical Science and Technology
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• 제12권2호
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• pp.167-172
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• 2021

he progressively improved sensing sensitivity (∆λ_SPR/∆n, nm/RIU) to detect the refractive index is observed on the SPR platform of an Au-covered epoxy gratings in an increase in potential cycling in a typical three-electrode cell. Here, a DVD-R optical disc was used as a structure template to prepare an Au-covered epoxy gratings, and the newly formed reverse track pitch structure on the epoxy substrate was used as a working electrode directly in aqueous sulfuric acid solution. It is expected that Au reconstruction by potential cycling in sulfuric acid electrolyte increases the packing density of Au atoms in the grain boundary and improves the propagation of electromagnetic waves.

• Journal of the Korean Wood Science and Technology
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• 제27권3호
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• pp.73-81
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• 1999

가장 보편적으로 사용되고 있는 도공용 안료인 클레이와 탄산칼슘의 배합비율을 실제 도공공정의 안료 혼합비와 근사하게 설정한 후, 이온성 라텍스를 적용해 봄으로서 이들의 상호작용과 도공지의 품질에 미치는 영향에 대해 검토해 보았다. 1,2급 클레이를 각각 35부, 탄산칼슘을 30부씩 혼합한 후, 제조한 도공액의 탈수량 및 침강중량비 측정 결과, 양성라텍스는 음이온성 라텍스보다 다분산 안료 배합하에서도 안료와의 상호작용이 크다는 것을 알 수 있었으며, 형성된 필터케이크충의 구조가 다공성임을 알 수 있었다. 이러한 결과는 제조한 도공지의 표면거칠기 및 투기도 등의 도공지 표면 및 내부육특성 측정을 통해 확인할 수 있었다. 결과적으로 양성라텍스를 사용하여 제조한 도공지의 인쇄적 성이 음이온성 라텍스를 사용한 경우보다 우수하였다. 이는 양성라텍스가 탄산칼슘이 일정비율 첨가된 안료 배합조건 하에서도 이오기의 전하반전 특성을 통해 클레이와의 정전기적 상호작용을 할 수 있다는 사실을 보여주었으며, 1급 클레이의 혼합비율 일부를 2급 및 탄산칼슘으로 대체하여 도공지의 품질 및 인쇄적성을 개량하였다.