• Transactions on Electrical and Electronic Materials
• /
• 제12권3호
• /
• pp.93-97
• /
• 2011

In this paper, we discuss design considerations for an n-channel metal-oxide-semiconductor field-effect transistor (MOSFET) with a lateral asymmetric channel (LAC) doping profile. We employed a 0.35 ${\mu}M$ standard complementary MOSFET process for fabrication of the devices. The gates to the LAC doping overlap lengths were 0.5, 1.0, and 1.5 ${\mu}M$. The drain current ($I_{ON}$), transconductance ($g_m$), substrate current ($I_{SUB}$), drain to source leakage current ($I_{OFF}$), and channel-hot-electron (CHE) reliability characteristics were taken into account for optimum device design. The LAC devices with shorter overlap lengths demonstrated improved $I_{ON}$ and $g_m$ characteristics. On the other hand, the LAC devices with longer overlap lengths demonstrated improved CHE degradation and $I_{OFF}$ characteristics.

• 한국전기전자재료학회논문지
• /
• 제31권7호
• /
• pp.510-514
• /
• 2018

This study discusses and demonstrates the structural stability of highly ordered Pt patterns formed on a transparent and flexible substrate through the process of nanotransfer printing (nTP). Bending tests comprising approximately 1,000 cycles were conducted for observing Pt line patterns with a width of $1{\mu}m$ formed along the direction of the horizontal (x-axis) and vertical (y-axis) axes ($15mm{\times}15mm$); and adhesion tests were performed with an ultrasonicator for a period greater than ten minutes, to analyze the Pt crossbar patterns. The durability of both types of patterns was systematically analyzed by employing various microscopes. The results show that the Pt line and Pt crossbar patterns obtained through nTP are structurally stable and do not exhibit any cracks, breaks, or damages. These results corroborate that nTP is a promising nanotechnology that can be applied to flexible electronic devices. Furthermore, the multiple patterns obtained through nTP can improve the working performance of flexible devices by providing excellent structural stability.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
• /
• pp.213-213
• /
• 2000

Direct laser vaporization of transition-metal(Co, Ni)/graphite composite pellet produced single wall carbon naotubes(SWNT) in the condensing vapor in a heated flow cylinder-type tube furnace, Transition metal/graphite composite pellet target was made by mixing graphite, Co, and Ni in 98:1:1 atomic weight ratios, pressing the mixed powder, and curing it. The target was placed in a tube furnace maintained at 1200$^{\circ}C$ and Ar inert collision gas continuously flowed into the tube. The 2nd harmonic, 532nm wavelength light from Nd-YAG laser was used to vaporize the tube. The carbon nanotubes produced by the laser vaporization were accumulated on quartz tube wall. The raw carbon nanotube materials were purified with surfactants(Triton X-100) in a ultrasonicator. These carbon nanotubes were analyzed using SEM, XRD, and Raman spectroscopic method. The carbon nanotube growth on the Ni-patterned Si substrate was investigated by the CVD process. Transition-metal, Ni and CH4 gas were used as a catalyst and a reactant gas, respectively. The structure and the phonon frequencies of the carbon nanotubes formed on the patterned Si substrate were measured by SEM and Raman spectrometer.

• 대한수의학회지
• /
• 제25권1호
• /
• pp.77-89
• /
• 1985

The agar gel precipitation(AGP), indirect hemagglutination(IHA) and indirect enzyme immunoassay(IEIA) tests were used to detect antibodies in pigs naturally infected with Cysticercus cellulosae in Jeju. The results obtained were summarized as follows: 1. Sera collected from pigs naturally infected with Cysticcrcus cellulosae did not react in AGP test. 2. In the IHA test for swine cysticercosis, the peak titers observed were between 1:20 and 1:160 and non-specific reaction was recognized with a few samples among control sera. 3. In the IEIA test, optical density(OD) values were obtained the best results under the condition of OPD-substrats are reacted at room temperature for 5minutes. The OD values of greater than 0.2 were determined as positive and the high titers in positive sera ranged from 1:40 to 1:1,080. 4. Antibodies to swine cysticercosis were detected by IHA and IEIA tests but the latter was more sensitive and specific than the former. 5. In the preparation of Cystisercus antigens, saline extract which was prepared the precipitate of internal membrane treated ultrasonicator were better results than other antigens for serological tests. 6. Amounts of protein in antigens was not related in direct proportion to results of serological reaction.

• 한국전기전자재료학회논문지
• /
• 제32권5호
• /
• pp.432-436
• /
• 2019

In this study, we produced a light, flexible, wearable gas sensor by depositing MWCNTs (Multi-walled Carbon Nanotubes) into nylon. MWCNTs are widely used as a gas sensor material due to their excellent mechanical, electrical and physical characteristics. We produced a gas sensor to detect NOx gases by depositing nylon yarn in a MWCNT solution. The MWCNT solution was made by mixing 3 mg MWCNT in 5 ml of ethanol. Nylon yarn was placed in the manufactured solution and ultrasonic waves were applied using an ultrasonicator for 3 h, resulting in MCWNT deposition. The MWCNT-deposited nylon yarn was dried at room temperature for 24 h. The MWCNT-thin-film-coated nylon yarn was masked 1 mm apart, and gold was then deposited on the masked nylon yarn to create the gas sensor. The sensor then was installed in a chamber with a controlled atmospheric environment and exposed to NOx gas. The changing signal from the sensor was amplified to analyze its gas detection characteristics.

• 마이크로전자및패키징학회지
• /
• 제19권4호
• /
• pp.65-69
• /
• 2012

복합도금이란 금속 도금층을 매트릭스로 세라믹, 폴리머, 나노분말과 같은 입자를 공석시켜 경도의 향상, 내마모성, 내식성, 자기 윤활성 등의 특성을 갖는 복합 금속피막을 얻어내는 방법으로 본 연구에서는 나노입자로 $TiO_2$를 사용하여 니켈과 함께 복합도금층을 형성하였다. $TiO_2$를 첨가시킨 복합전기도금을 통해 표면저항성 향상, 광분해 효과를 기대할 수 있다. 용액조건 중 pH 변화에 따른 zeta전위를 측정하였다. 초음파처리를 통한 물리적인 방법으로 용액 중 나노분말의 응집을 최소화한 후 $TiO_2$-Ni 복합도금을 실시하였다. 최적의 도금 조건으로 $50^{\circ}C$에서 pH 3.5, 전류밀도 $40mA/cm^2$에서 가장 효과적이었으며 Ti의 함량은 $50^{\circ}C$에서 15-20 at.%로 확인되었다.

• 폴리머
• /
• 제28권2호
• /
• pp.128-134
• /
• 2004

비타민E 아세테이트를 봉입하고 있는 셀룰로오스 나노입자는 개선된 자발적 유화확산 방법을 이용하여 제조하였다. 셀룰로오스 나노입지는 셀룰로오스 유도체와 비타민E 아세테이트를 아세톤/에탄올 혼합유기 용매로 용해한 다음 초음파 발생장치를 이용하여 폴리(옥시에틸렌 솔비탄 모노올레이트) 용액에 분산하여 제조하였다. 입자크기와 비타민 E 아세테이트의 봉입률은 광산란 장치와 UV 분광계를 이용하여 각각 측정하였다. 나노입자의 안정성은 상온에서 30일간 입자크기 변화를 통해 비교하였고 입자의 형태는 주사전자 현미경을 통해 관찰하였다. 결과적으로 제조된 나노입자의 형태는 구형인 것을 관찰하였고, 상온에서 30일간 입자크기 변화가 없었다. 가장 좋은 셀룰로오스 나노입자의 제조 조건은 1% w/v 니트로셀룰로오스와 8% w/v 폴리(옥시에틸렌 솔비탄 모노올레이트)를 사용하였을 경우이고, 이때 나노입자의 크기는 65nm, 비타민E 아세테이트의 봉입률은 71%의 값을 나타내었다.

• 한국물환경학회지
• /
• 제30권5호
• /
• pp.512-516
• /
• 2014

Two different methods for TOC (Total Organic Carbon) analysis of livestock manure including high strength solid organics were evaluated. Firstly, an analyzing method by dilution after pre-treated by Ultrasonicator and 100 mesh sieve for homogenization was defined as TOC 1; and secondly method divided by particulate organic carbon (POC) and dissolved organic carbon (DOC) was defined as TOC 2. 116 samples collected from 56 farms were analyzed in TOC1, TOC2, BOD and VSS. TOC1 method showed higher accuracy at less than 30,000 mg/L of TOC while TOC2 method presented significant reliability at over that concentration. Regarding to the sample with the same VSS concentration, the correlation between TOC 2 and VSS (${\rho}$: 0.806) was slightly higher than that between TOC 1 and VSS (${\rho}$: 0.784), resulted from a relatively low loss of solids and a low error probability (dilution and homogenization effects) in the analyzing procedures. In addition, the reliability between POC and VSS in TOC2 was high and the POC was about 4.4 fold that of the VSS. Consequently, TOC 2 without dilution effect was assessed as a proper method to increase the analyzing accuracy of swine manure including high solid organics.

• 한국식품영양학회지
• /
• 제17권2호
• /
• pp.163-170
• /
• 2004

계란찜 제조시 물의 첨가량,가열 온도와 시간, pH, NaCl의 첨가량이 전란액의 점도와 색, 계란찜의 텍스쳐와 색에 미치는 영향을 조사하였다. 계란찜은 계란을 할난시켜 완전히 섞어 계란액을 만든 다음ultrasonicator로 탈기시키고 10$0^{\circ}C$의 증기로 7분간 가열한 다음 22$^{\circ}C$에서 90분간 냉각시켰다. 그 결과 물의 첨가량은 50% 이상부터 계란액의 점도와 계란찜의 견고성 및 항복응력에 현저한 감소가 있었다. 계란액의 색은 a와 b값의 감소가 현저하였고, 계란찜은 ( - )값 범위에서의 a값이 더 낮아져 녹색이 짙어짐을 보였다. 가열 온도의 증가는 응고시간의 단축과 높은 항복응력이 측정되었으나 변형도는 감소함을 보였다. 가열시간에 따른 계란찜의 L과 b값은 9$0^{\circ}C$와 10$0^{\circ}C$에서 감소함을 보였고, a값은 8$0^{\circ}C$에서 감소함을 보였다. 소금의 첨가를 1.3%까지 하였을 때 계란찜의 항복응력과 단단함이 크게 증가하였지만, 색은 약간의 b값 감소 외에는 큰 차이가 없었다. 계란액의 pH를 4.0에서 10.0으로 증가시켰을 때 pH 6.0에서 점도가 가장 낮았으나 계란찜은 항복응력과 단단함에서 가장 높은 값을 보여주었고 pH 8.0 이상에서는 L값과 b값의 감소가 현저하였다. 이상의 결과에서 물의 첨가량과 가열온도, 가열시간, 소금첨가량은 계란찜의 텍스쳐 및 색특성에 영향을 줌이 밝혀졌다.

• 한국전기전자재료학회논문지
• /
• 제24권7호
• /
• pp.574-577
• /
• 2011

In this study, we use the $2.5cm{\times}7.5cm$ soda lime glass as the substrate. We used the ultrasonicator. Glass was dipped in the acetone, methanol and DI water respectively for 10 minutes. Ar(99.99%)gas was used as the sputtering gas. We varied the RF power between 100~175 W with 25 W steps. Base pressure was kept by turbo molecular pump at $3.0{\times}10^{-6}$ torr. Working pressure was kept by injection of Ar gas. ZnS thin films were deposited with the radio frequency magnetron sputtering technique at various temperatures and sputtering powers. It is also clearly observed that, the intensity of the (111) XRD peak increases with increasing the RF power. Electrical properties were measured by hall effect methods at room temperature. The resistivity, carrier concentration, and hall mobility of ZnS deposited on glass substrate as a function of sputtering power. It can be seen that as the sputtering power increase from 100 to 175 W, the resistivity of the films on glass decreased significantly from $8.1{\times}10^{-2}$ to $1.2{\times}10^{-3}\;{\Omega}{\cdot}cm$. This behavior could be explained by the effect of the sputtering power on the mobility and carrier concentration. When the RF power increases, the carrier concentration increases slightly while the resistivity decreases significantly. These variation originate from improved crystallinity and enhanced substitutional doping as the sputtering power increases.