• 통합자연과학논문집
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• 제12권4호
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• pp.116-121
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• 2019

This experiment is to evaluate the physical properties of the hydrogel lens with the addition of carbon-based nanomaterials, Graphene oxide and Carbon nanotube, and to confirm the improvement of strength. Hyaluronic acid, a hydrophilic substance, was used as an additive by using HEMA (2-hydroxyethyl methacrylate) and ethylene glycol dimethacrylate (EGDMA) as a base monomers. Graphene oxide and two types of Carbon nanotubes(Amide functionalized and Carboxilic acid functionalized) were added 0.1%, 0.3%, 0.5%, respectively, and the physical properties were analyzed by measuring water content, refractive index, breaking strength and SEM image. In the case of the sample added with each carbon nano material, the water content tended to increase for all three materials. The breaking strength tended to increase in Graphene oxide and Carbon nanotube; Carboxilic acid functionalized, but in the case of Carbon nanotube; amide fuctionalized, the breaking strength tended to decrease. However, Carbon nanotube; amide fuctionalized had the highest breaking strength among the three nano materials. Thus, the addition of certain carbon nanomaterials seems to be appropriate for improving the strength of hydrogel lenses.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.236-237
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• 2006

We have investigated volume resistivity showed by changing the content of Carbon nanotube and carbon black which is the component parts of semiconducting shield in underground power transmission cable. Specimens were made of sheet form with the six of specimens for measurement. Volume resistivity of specimens was measured by volume resistivity meter after 10 minutes in the preheated oven of both $23{\pm}1[^{\circ}C]$ and $90{\pm}1[^{\circ}C]$. The volume resistivity decreased by adding Carbon nanotube and carbon black. Also the volume resistivity had different properties because of PTC/NTC tendencies at between $23[^{\circ}C]$ and $90[^{\circ}C]$. We experimented with electric properties of semiconducting components with fewer Carbon nanotube than carbon black.

• 대한공업교육학회지
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• 제32권2호
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• pp.188-198
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• 2007

이 연구의 목적은 열처리 방법으로 탄소나노튜브에 백금나노 입자를 담지하는 것이다. 이 목적을 달성하기 위해서 염화백금산 수용액으로부터 hexachloro platinate(IV)를 탄소나노튜브에 흡착시킨 후 환원제를 사용하지 않고 질소분위기에서 $400^{\circ}C$로 열처리 하여 백금 나노입자를 담지 시켰다. 탄소나노튜브에 흡착된 hexachloro platinate(IV)의 함량은 UV-visible spectrophotometer를 사용하여 정량하였고, 탄소나노튜브에 담지된 백금 나노입자 존재와 분산을 확인하기 위해서 열중량분석, X-ray 회절분석, 투과전자현미경 관찰을 수행하였다. hexachloro platinate(IV)를 흡착시킨 탄소나노튜브를 환원제를 사용하지 않고 질소분위기에서 $400^{\circ}C$에서 열처리하면 2 nm 이하의 백금 나노입자가 균일하게 분포되었다. 한편, $800^{\circ}C$에서 열처리한 경우에는 백금입자들이 상호 응집현상이 발생하여 백금 입자의 크기가 커지고 분산이 균일하지 못했다. 따라서 hexachloro platinate(IV)를 탄소나노튜브에 흡착시킨 후 질소분위기에서 $400^{\circ}C$의 간단한 열처리를 통해서 백금 나노입자를 담지시킬 수 있었다.

• Journal of Magnetics
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• 제7권3호
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• pp.98-100
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• 2002

Tunnel magnetoresistive devices using an individual multi-walled carbon nanotube were fabricated and their low-temperature electrical transport propertiers were investigated. With the ferromagnetic Co electrodes, the multi-walled carbon nanotube exhibited hysteretic magnetoresistance curve at low temperatures. Depending on the temperature and the bias current, the magnetoresistance ratio can be as high as 16% at the temperature of 2.2 K. Such high magnetoresistance ratio indicates a long diffusion length of the multi-walled carbon nanotube.

• 한국전기전자재료학회논문지
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• 제26권12호
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• pp.924-927
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• 2013

In this study, we proposed CMP-PLAs to replace the Al heat sinks as heat sink materials, and investigated heat dissipation characteristics of the LED lighting devices using them. The crystallinity of the proposed CMP-PLA heat sinks decreased with increasing carbon nanotube contents in CMP-PLA. However, the thermal conductivity was improved with the increase of the carbon nanotube contents. The heat dissipation characteristics of the LED lighting devices using CMP-PLA heat sinks was improved with increasing carbon nanotube contents in CMP-PLA. For the LED lighting devices using CMP-PLA heat sinks with 40% carbon nanotube contents, the initial temperature measured at the heat sink plate was $27^{\circ}C$, which increased as time, and it was saturated around $56^{\circ}C$ after an hour. The LED lighting devices using CMP-PLA heat sinks are expected to be functional materials that can reduce their weight and improve their electric properties, compared to those using existing Al heat sinks.

• 한국정밀공학회지
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• 제23권12호
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• pp.122-127
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• 2006

This paper reports on the development of carbon nanotube tip modified with focused ion beam(FIB). We used an electric field which causes dielectrophoresis, to align and deposit CNTs on a metal-coated canning Probe Microscope (SPM) tip. Using the CNT attached SPM tip, we have obtained an enhanced resolution and wear property compared to that from the bare silicon tip through the scanning of the surface of the bio materials. The carbon nanotube tip was aligned toward the source of the ion beam allowing their orientation to be changed at precise angles. By this technique, metal coated carbon nanotube tips that are several micrometer in length are prepared for SPM.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.126-127
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• 2005

Semiconductor carbon nanotube was grown on oxided silicon wafer with Atmosphere Pressure Chemical Vapor Deposition (APCVD) ethmod and investigated the electrical property after thermal oxidation at 300$^{\circ}C$ in air. The electrical property was measured at room temperature in air after thermal oxidation at 300$^{\circ}C$ for various times in air. Semiconductor carbon nanotube was steadily changed to metallic carbon nanotube as increasing of thermal oxidation times at 300$^{\circ}C$ in air.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.542-546
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• 2004

Fully non-local Quasicontinuum method using sub-divided region with Hermite interpolation function is proposed for simulation of carbon nanotube. Tersoff-Brenner potential is adopted for interaction of bonded atoms and also van der Waals force for non-bonded interaction. Bending of single wall carbon nanotube with chirality (20,0) and 15nm length is simulated up to 90 degree. Bending of double wall carbon nanotube with chirality (20,0) and (12,0) is simulated up to 65 degree. Bending of four wall carbon nanotube is simulated up to 45 degree.

• 한국정밀공학회지
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• 제21권6호
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• pp.167-171
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• 2004

In this paper, we proposed a new method to control the length of carbon nanotube using electrochemical etching. We made a nano probe that was composed of the tungsten tip and multi-wall carbon nanotube. The nano probe was placed on the nano stage and the carbon nanotube on the nano probe was etched in the electrolyte solution with the applied voltage. The overall procedures were done under optical microscope and can be monitored. We can obtain a nano probe with proper length through this procedure.

• 한국운동역학회지
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• 제22권2호
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• pp.237-242
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• 2012

The purpose of this study was (a) to develop carbon nanotube-based shock absorbers for reducing potentially harmful impact forces and excessive foot pronation, and (b) to briefly determine how the effects of carbon nanotube-based shock absorbers on biomechanical variance during drop landing. A university student(age: 24.0 yrs, height: 176.2 cm, weight: 679.5 N) who has no musculoskeletal disorder was recruited as the subject. Hardness, specific gravity, tensile strength, elongation, 100% modulus, tear strength, split tear strength, compression set, resilience, vertical GRF, and loading rate were determined for each material. For each dependent variable, a descriptive statistics was used for different conditions. The property test results showed that tensile strength, tear strength, split tear strength, compression set, and resilience in carbon nanotube-based shock absorbers were greater than general Ethylene Vinyl Acetate(EVA). These indicated that resistance against variable strength in developed carbon nanotube-based shock absorbers were greater than general EVA. In vertical GRF of CNTC was less than those of EVA during drop landing and loading rate of CNTC was greater than EVA. It seems that the use of CNT can be a effective way of reducing and controlling shock from impact.