• Korean Chemical Engineering Research
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• 제44권5호
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• pp.528-534
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• 2006

고온 플라즈마가 적용된 플라즈마트론을 이용하여 바이오가스 개질을 통해 수소를 생산하는데 있어서 최적 운전 조건에 대해 연구하였다. 음식물 쓰레기의 혐기성 발효조에서 생성된 바이오가스 구성비($CH_4/CO_2$)가 1.03, 1.28, 2.12인 바이오가스로 개질실험을 수행하고, 수소 생산과 메탄 전환율을 향상시키기 위해 바이오가스 유량비, 수증기 유량비, 입력전력 변화와 같은 변수별 연구를 수행하였다. 바이오가스 유량비(biogas/TFR : total flow rate), 수증기 유량비($H_2O/TFR$: total flow rate), 입력전력이 각각 0.32~0.37, 0.36~0.42, 8 kW일 때 메탄의 전환율이 81.3~89.6％인 최적운전조건을 보였다. 이때 합성가스 중의 수소와 일산화탄소의 농도는 27.11~40.23％, 14.31~18.61％이며, 수소 수율은 40.6~61％, 에너지 전환율은 30.5~54.4％, $H_2/CO$ 비는 1.89~2.16이다.

• Archives of Pharmacal Research
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• 제13권3호
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• pp.221-226
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• 1990

A physiological pharmacokinetic hybrid model was developed in order to predict the disposition kinetics of diphenylhydantoin (DPH) in the brain from the plasma conentration data of DPH. The model was constructed under the assumptions of well-stirred, plasma flow-limited and lienar tissue diposition kinetics of DPH. DPH was administered intravenously to the rats at a dose of 10 mg/kg together with/without sodium salicylate (SA;10 mg/kg) and the DPH concentrations in the plasma and brain were determined. Plasma protein binding of DPH concentrations in the plasma and brain were determined. Plasma protein binding of DPH was also determined using equilibrium dialysis technique. Then the model was tested for its predictability of DPH concentrations in the brian from the plasma data of DPH. It was found that the predicted values of DPH concentrations in the brian were in fair agreement with the experimental values in the rats of both treatments. The 2-fold increase in the brain concentration of DPH by SA-coadinistration was predicted well from the plasma concentration and plasma free fraction ($f_p$) data of DPH using the model. Therefore, the hybrid model was concluded to be very useful for the prediction of the concentrations of DPH in the brain from the plasma concentration data. Finally, DPH concentrations in the human brian was calculated using this model from plasma DPH data in the literature, yet the scale-up of this model to the human is not convinced.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2001년도 춘계학술발표회 초록집
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• pp.72-72
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• 2001

Plasma polymerized thin films have been deposited on Si(lOO) substrates at $25-400^{\circ}C$ using thiophene ($C_4H_4S$) precursor by plasma assisted chemical vapor deposition (PACVD) method for low-dielectric device application. In order to compare physical properties of the as-grown thin films, the effects of the plasma power, gas flow ratio and deposition temperature on the dielectric constant and thermal stability were mainly studied. XRD and TED studies revealed that the as-grown thin films have highly oriented amorphous polymer structure. XPS data showed that the polymerized thin films that grown under different RF power and deposition temperature as well as different gas ratio of $Ar:H_2$ have different stoichiometric ratio of C and S compared with that of monomer, indicating a formation of mixture polymers. Moreover, we also realized that oxygen free and thermally stable polymer thin films could be grown at even $400^{\circ}C$. The results of SEM, AFM and TEM showed that the polymer films with smooth surface and sharp interface could be grown under various deposition conditions. From the electrical property measurements such as I-V and C-V characteristics, the minimum dielectric constant and the best leakage current were obtained to be about 3.22 and $10-11{\;}A/\textrm{cm}^2$, respectively.

• 한국결정성장학회지
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• 제15권1호
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• pp.10-15
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• 2005

Microwave plasma CVD 다이아몬드/Ti 박막 성장 시 CH₄/H₂ 가스의 유량비율, chuck bias, microwave power 등이 다이아몬드 박막의 구조적 특성과 입자밀도에 미치는 영향에 대하여 조사하였다. 2∼3 CH₄ Vol.% 조건일 때 sp³-결합성의 탄소 neutral 들이 우선적으로 형성되고 sp²-결합성의 탄소 neutral 들이 선택적으로 제거됨에 따라 양질의 다이아몬드 박막을 얻을 수 있었으며, 다이아몬드 입자 증착 기구를 해석하였다. Ti 기판에 걸어준 negative chuck bias가 증가함에 따라 다이아몬드 핵생성이 증진되어 다이아몬드 입자 밀도가 증가하였고, 임계 전압은 약 -50V 임을 확인하였다. 또한, microwave power가 증가함에 따라 미세결정질(micro-crystalline) graphite 층 생성이 제어되고 다이아몬드 층이 형성됨을 확인하였다.

• 한국산업융합학회 논문집
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• 제6권1호
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• pp.81-86
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• 2003

For the simultaneous removal of $SO_2$/NOx from an iron-ore sintering plant, industrial plasma experiments have been conducted with a flue gas flow rate of $5,000Nm^3/hr$. The maximum 40kW power using the magnetic pulse compression (MPC) system generates a peak value of 100-150kV pulse voltage with its risetime of 200nsec and full width at half maximum (FWHM) of 500nsec, and with a frequency <300Hz. The plasma reactor module adopts a wire-plate structure with a gap of 200-400mm ID between plates. Initial concentrations of $SO_2$ and NOx were around 100-150ppm, respectively in the presence of 15% $O_2$ and <10% $H_2O$. Various reaction parameters such as specific energy ($Whr/Nm^3$), $NH_3$ injection with corona discharge, flow rate and injection of hydrocarbons were investigated for $SO_2$/NOx removal characteristics. About 90/65% of $SO_2$/NOx were simultaneously removed with a specific energy of $3.0Whr/Nm^3$ when both $NH_3$ and hydrocarbons were injected. Practical implications that the pilot-scale plasma results provide are further discussed.

• 한국표면공학회지
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• 제46권4호
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• pp.168-174
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• 2013

In this study, low-cost, high-speed deposition, excellent processability, high mechanical strength and electrical conductivity, chemical stability and corrosion resistance of stainless steel to meet the obsessive-compulsive (0.1 mm or less) were selected CrN thin film. new price reduction to sputter deposition causes - the possibility of sublimation source for inductively coupled plasma Cr rods were attempts by DC bias. 0.6 Pa Ar inductively coupled plasmas of 2.4 MHz, 500 W, keeping Cr Rod DC bias power 30 W (900 V, 0.02 A) is applied, $N_2$ flow rate of 0.5, 1.0, 1.5 sccm by varying the characteristics of were analyzed. $N_2$ flow rate increases, decreases and $Cr_2N$, CrN was found to increase. In addition to corrosion resistance and contact resistance, corrosion resistance, electrical conductivity was evaluated. corrosion current density than $N_2$ 0 sccm was sure to rise in all, $N_2$ 1 sccm at $4.390{\times}10^{-7}$ (at 0.6 V) $A{\cdot}cm^{-2}$, respectively. electrical conductivity process results when $N_2$ 1 sccm 28.8 $m{\Omega}/cm^2$ with the lowest value of the contact resistance was confirmed that came out. The OES (SQ-2000) and QMS (CPM-300) using a reactive deposition process to add $N_2$ to maintain a uniform deposition rate was confirmed that.

• 폴리머
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• 제32권1호
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• pp.38-42
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• 2008

메탄, 아세틸렌, hexamethyldisiloxane(HMDSO) 및 HMDSO+산소를 플라스마 중합시켜 식품포장용으로 사용되고 있는 저밀도 폴리에틸렌(LDPE) 필름의 표면에 얇은 박막을 코팅하여 LDPE 필름의 차단성을 향상시키고자 하였다. 산소에 대한 차단성은 HMDSO+산소(유량 : 0.6+9.0 SCCM) 플라스마로 40 W에서 10분간 코팅할 경우 가장 크게 향상되어 산소 투과도가 18.6배까지 감소되었으며, 이산화탄소와 수분에 대한 차단성은 아세틸렌(유량 : 0.75 SCCM) 플라스마로 10 W에서 10분간 코팅할 경우 가장 크게 향상되어 이산화탄소와 수분 투과도가 각각 12.0배와 3.0배까지 감소되었다. 또한, 이렇게 코팅된 필름을 사용하여 방울토마토, 오이, 팽이버섯 등을 포장할 경우, 신선도 유지기간이 코팅 전에 비하여 $1.5{\sim}3.0$배까지 연장되었다.

• 반도체디스플레이기술학회지
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• 제15권4호
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• pp.27-32
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• 2016

In recent years, various researches have been conducted to improve process yields in accordance with miniaturization of semiconductor. APC(Advanced Process Control) is considered one of the methods to increase in process yields. APC is a process control technology that maintains optimal process conditions and improves the reliability of results by controlling and formulating the relationship among the various process parameters and results. We built up an optical diagnostic system with a three-channel spectrometer. The system detects signals those represent the changes of specific emission peaks intensity versus each reference and converts it into MFC control signals to get back the changes to the reference state. Controlling the MFC continues until the specific peak intensity changes into the normal state. Through this device, we tested a APC automatically responding to process changes during the plasma process. We could control gas flow while sputtering process on going and improve uniformity of plasma intensity with this system. Finally, we have got results those enhance the plasma intensity non-uniformity to 7.7% from 15.5%. Also, found unexpected oxygen flow what is estimated to be come out from IGZO target.

• 한국식품과학회지
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• 제29권5호
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• pp.1067-1070
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• 1997

Chelating sepharose fast flow gel에 $Cu^{2+}$을 고정화시키고 이들과 단백질과의 친화력 정도에 의해서 용출용매를 통해 단백질을 분획하는 방식의 IMAC법을 이용하여 소의 혈장단백질로부터 IgG의 분리를 시도하였다. 대부분의 혈장단백질은 1차(0.01 M $Na_2HPO_4$, 0.5 M NaCl, pH 4.0)와 2차 용출용매(0.01 M imidazol)에 의하여 용출되었으며 역상 chromatography를 이용하여 각 분획의 단백질조성을 조사한 결과, 1차 용출용매에 의해서는 주로 albumin이, 그리고 2차 용출용매에 의해서는 IgG와 transferrin 등이 IMAC column으로부터 용출되었다. 2차 용출용매에 의해 얻어진 분획으로부터 분자량 100 kD이상의 단백질을 한외여과장치를 이용하여 농축하였을 때, IgG가 효과적으로 분리 정제 되었다.

• 한국표면공학회지
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• 제46권3호
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• pp.133-138
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• 2013

We have developed a 2D axi-symmetric numerical model for an inductively coupled plasma system in order to analyze gas mixing effect through a narrow gap shower head. For frictional flow, holes of 0.5 mm diameter and 2 mm length are approximately modeled in 2D. Gas velocity distribution 10 mm below the shower head showed 2 times difference between the center and the edge at 10 mTorr. At 10 mm above the wafer, it was increased to 6 times difference due to the pumping duct effect. The model with a 5 mm height buffer region of a shower head showed reasonable behavior of Ar discharge. The density of Ar metastable showed additional peak inside the buffer region around the edge holes.