• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.50-53
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• 2003

CMP (chemical mechanical polishing) process remained to solve several problems in deep sub-micron integrated circuit manufacturing process. especially consumables (polishing pad, backing film, slurry, pad conditioner), one of the most important components in the CMP system is the slurry. Among the composition of slurries (buffer solution, bulk solution, abrasive particle, oxidizer, inhibitor, suspension, antifoaming agent, dispersion agent), the abrasive particles are important in determining polish rate and planarization ability of a CMP process. However, the cost of abrasives is still very high. So, in order to reduce the high COO (cost of ownership) and COC (cost of consumables) in this paper, we have collected the silica abrasive powders by filtering after subsequent CMP process for the purpose of abrasive particle recycling. And then, we have studied the possibility of recycle of reused silica abrasive through the analysis of particle size and hardness. Also, we annealed the collected abrasive powders to promote the mechanical strength of reduced abrasion force. Finally, we compared the CMP characteristics between self-developed KOH-based silica abrasive slurry and original slurry. As our experimental results, we obtained the comparable removal rate and good planarity with commercial products. Consequently, we can expect the saving of high cost slurry.

• Restorative Dentistry and Endodontics
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• 제29권4호
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• pp.378-385
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• 2004

The purpose of this study was to compare the effects of preparation with GT files and profiles .04 in shaping of root canals and reconstruct the three-dimensional root canal system using micro computed tomography 40 canals of the extracted human mandibular molars were used, and randomly distributed into two experimental groups. In group 1. canals were prepared by GT files. In group 2, Profiles .04. were used. Apical preparation size was #30. For each tooth pre and post operative cross-sectional images were obtained by the micro CT at 50 micron intervals. Pre and post operative cross-sectional images of 1, 2, 3, 5, and 8mm from the apex were compared. For each section. canal area and centering ratio were determined. For each tooth pre- and post-operative root canal volume from the furcation to the apex of the roots was calculated by three-dimensional image software. Following results were obtained: 1. At 8mm from the apex, area of dentin removed by GT rotary file was significantly larger than that by Profile .04. And at the other levels there was not a significant difference. 2. There was a trend for GT rotary file to remain more centered in the canals than Profile .04 at all levels. But at 3mm level. there was a statistically significant difference. 3. In root canal volume increments after instrumentation, there was no significant difference between two groups.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.227-235
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• 2000

Agricultural products are easily deformable its shape because of some external forces. However, these force behavior is difficult to measure quantitatively. Until now, many researches on the mechanical property was performed with various methods such as material testing, chemical analysis and non-destructive methods. In order to investigate force behavior on the cellular unit of agricultural products, electro-microscope based 3D image processing method will contribute to analysis of plant cells behavior. Before image measurement of plant cells, plant sample was cut off cross-sectioned area in a size of almost 300-400 ${\mu}$ m units using the micron thickness device, and some of preprocessing procedure was performed with fixing and dyeing. However, the wall structure of plant cell is closely neighbor each other, it is necessary to separate its boundary pixel. Therefore, image merging and shrinking algorithm was adopted to avoid disconnection. After then, boundary pixel was traced through thinning algorithm. Each image from the electro-microscope has a information of x,y position and its height along the z axis cross sectioned image plane. 3D image was constructed using the continuous image combination. Major feature was acquired from a fault image and measured area, thickness of cell wall, shape and unit cell volume. The shape of plant cell was consist of multiple facet shape. Through this measured information, it is possible to construct for structure shape of unit plant cell. This micro unit image processing techniques will contribute to the filed of agricultural mechanical property and will use to construct unit cell model of each agricultural products and information of boundary will use for finite element analysis on unit cell image.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.159-160
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• 2006

A novel approach to the manufacture of biocompatible ceramic scaffold for tissue engineering using micro-stereolithography system is introduced. Micro-stereolithography is a newly proposed technology that enables to make a 3D micro structure. The 3D micro structures made by this technology can have accurate and complex shape within a few micron error. Therefore, the application based on this technology can vary greatly in nano-bio fields. Recently, tissue-engineering techniques have been regarded as alternative candidate to treat patients with serious bone defects. So many techniques to design and fabricate 3D scaffolds have been developed. But the imperfection of scaffold such as random pore size and porosity causes a limitation in developing optimum scaffold. So scaffold development with controllable pore size and fully interconnected shape have been needed for a more progress in tissue engineering. In this paper, bone scaffold was developed by applying the micro-stereolithography to the mold technology. The scaffold material used was HA(Hydroxyapatite) nano powder. HA is a type of calcium phosphate ceramic with similar characteristic to human inorganic bone component. The bone scaffold made by HA is expected, in the near future, to be an efficient therapy for bone defect.

• 한국진공학회지
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• 제12권2호
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• pp.144-149
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• 2003

주사전자현미경을 이용한 전자빔의 직접조사에 의해 실리콘 캔틸레버 위에 탄소상 탐침을 성장하였다. 오일확산 펌프의 잔류가스 분위기에서 실리콘 캔틸레버와 전자빔을 수직으로 정렬한 다음 전자현미경의 스폿 모드를 통해 전자빔을 일정시간 동안 조사시켜 탄소상 탐침을 성장시켰다. 주사전자현미경의 제어변수인 조사시간, 가속전압, 방출 전류, 전자빔 프로브 전류 등을 변화시킴으로써 다양한 종횡비를 가지는 탐침을 성장시킬 수 있었으며, 성장 위치의 표면 형상과 무관하게 탐침을 성장시킬 수 있었다. 그 결과 유효길이 0.5 $\mu\textrm{m}$, 바닥직경 90 nm,콘의 반각 $3.5^{\circ}$인 탐침을 성장시켰다. 탐침이 없는 캔틸레버에 고종횡비 탄소상 탐침을 성장시킬 수 있는 기술은 PZT 박막구동기가 집적화된 AFM 캔틸레버의 탐침 형성 과정에서 발생하는 제작과정의 번거로움을 극복하는데 적용될 수 있다.

• 한국진공학회지
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• 제7권2호
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• pp.118-126
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• 1998

반도체 접촉구를 메우기 위하여 소오스의 직진성을 향상시키기 위한 연구를 수행하 였다. 이온화클러스터빔 증착법을 이용하는 동시에 셀의 구조를 개선하여 직진성 향상을 도 모하였다. 중성클러스터 만으로 구리를 증착할 경우 직진성은 매우 우수하였으나 소오스의 표면 이동이 적어 박막은 주상형으로 성장하며 측벽에의 증착은 거의 일어나지 않았으며 성 장에 따라 그림자효과로 인한 단차에서의 벽개가 관찰되었다. 그러나, 가속전압을 인가하여 전하를 띤 클러스터를 형성시켜 증착하였을 때 주상형 성장 모드는 사라졌으며, 직경 0.5$\mu$ m, aspect ratio 2의 접촉구에서 완벽한 바닥면의 도포성을 나타내었고, 측벽에의 증착성도 향상되어 막의 연결성이 개선되었다. 이로써 이온화 클러스터빔 증착법이 직진성을 향상시 켜 작은 접촉구의 메움을 향상시킬수 있는 물리적 증착 방법임을 확인하였다.

• 자원환경지질
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• 제22권3호
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• pp.207-219
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• 1989

Eight under 2 micron size fractions of the montmorillonite from Jugjeonri area, Gyeongsanbug-do, were studied and then this result has been compared with data from Yongdongri area. Montmorillonites occurring at the same stratigraphic horizon in each area show limited variation in chemical composition, but shows some degree of differences in exchangeable cation compositions and total layer charges of montmorillonites from Jugjeonri to Yongdongri area. In general, samples from Jugjeonri show higher amount of exchangeable Na and layer charge due to relatively higher substitution of Mg for Al in octahedral sites than those from Yongdongri area. But Their dehydroxylation endothermic peaks of the samples from both areas are abnormal type with a small range of variation of peak temperature. This variation seems to reflect tetrahedral substitution of AI for Si for samples from Yongdongri whereas samples from Jugjeonri do not show shuch a tendency. However, samples from Jugjeonri proved to be relatively higher dehydroxylation peak temperatures than those of the other. DSC data for sample from Jugjeonri also show that divalent-cation saturated montmorillonite have relatively a higher endothermic heat capacities than monovalent-cation saturated one as shown in previous work. Two different morphologies of montmorillonites, honeycomb structure and closely packed intergrowth, by SEM were observed in samples from both areas but the later one is common. The scalloped type is relatively abundant in the sample from Yongdongri than the other. The dominant habit by TEM are irregularly shaped foliated aggregates and platy shaped particles. In general, foliated aggregates which are easy to disperse are relatively abundant in the samples from Jugjeon compared with those from Yongdongri area.

• 공업화학
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• 제19권4호
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• pp.402-406
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• 2008

자유 라디칼 중합법으로 친 이산화탄소성 단량체인 퍼플로로데실메타크릴레이트(FDMA)와 산에 불안정한 단량체인 tert-부틸메타크릴레이트(TBMA)로 구성된 랜덤 공중합체를 합성하였다. 합성된 공중합체의 이산화탄소에 대한 용해도 특성 및 365 nm 노광에서의 포토레지스트 감도 특성에 관하여 조사하였다. 또한, 랜덤 공중합체를 이용하여 형성된 패턴을 플라즈마 에칭을 통해 전도성 고분자인 poly(styrenesulfonate): poly(3,4-ethylenedioxythiophene) (PSS : PEDOT)에 전사하여 미크론크기의 PSS : PEDOT 패턴을 제조할 수 있었다.

• 한국자동차공학회논문집
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• 제19권5호
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• pp.134-142
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• 2011

Although combustion is essential in most energy generation processes, it is one of the major causes of air pollution. Exhaust pipes with circular fin were designed to study the effect of cooling the recirculated exhaust gases (EGR) of Diesel engines on the chemical composition of the exhaust gases and the reduction in the percentages of pollutant emissions. The gases examined in this study were oxides of nitrogen (NOx), carbon dioxide ($CO_2$) and carbon monoxide (CO). In addition, $O_2$ concentration in the exhaust was measured. The designs adopted in this study were about exhaust pipes with solid and hollow fins around them direct surface force measurement in water using a nano size colloidal probe technique. The direct force measurement between colloidal surfaces has been an essential topic in both theories and applications of surface chemistry. As particle size is decreased from micron size down to true Carbon nano Colloid size (<10 nm), surface forces are increasingly important. Nano particles at close proximity or high solids loading are expected to show a different behavior than what can be estimated from continuum and mean field theories. The current tools for directly measuring interaction forces such as a surface force apparatus or atomic force microscopy (AFM) are limited to particles much larger than nano size. This paper use Water and CNC fluid at normal cooling system of EGR. Experimental result showed all good agreement at Re=$2.54{\times}10^4$ by free convection and Re=$3.36{\times}10^4$ by forced air furnace.

• 분석과학
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• 제23권6호
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• pp.579-586
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• 2010

현재 상업적으로 널리 사용 되여 지고 있는 항암제인 hydroxy urea, 6-mercaptopurine monohydrate, cytosine arabinoside, cyclophosphamide monohydrate 그리고 uracil를 3-(triethoxysilyl) propyl isocyanate 와 반응시켜 항암제가 붙어있는 3-(triethoxysilyl)propyl amide (compound I)을 합성한후 물과 가수분해 반응시켜 항암제가 결합된 silica 나노입자(10 nm~micronparticles)를 만들 수있었다. Silyl isocyanate 유도체들은 물과 반응하여 유기물질-silica 나노입자가 포함된 $-CH_2-CH_2-CH_2-NH-COOH$ 그룹이나 혹은 온도와 용매등 반응조건에 따라서 decarboxylated 된 propylamine 그룹이 생성되었다. 생체외 시험에서 항암제가 결합된 silica 나노입자는 종양 세포 제거에 효과적이고 정상세포에 거의 영향을 미치지 않는 것으로 나타났다. 그리고 악성 종양인 폐, 난소, 악성 흑색종, 중추신경계(CNS)와 결장 종양 세포가 이 연구에 사용되었다. 현재의 연구에서 전달매체 로서 silica는 silation 반응으로 손쉽게 나노입자를 얻을 수 있으므로 본 연구에 쉽게 이용 할 수 있다. 결과로부터 이 기술은 보다 부작용이 적은 생체 의약품에 적합한 carrier nanoparticles에 적용 될 수 있을 것으로 판단된다.