• Title/Summary/Keyword: $N_2$ plasma treatment

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Inactivation of Sewage Microorganisms using Multi-Plasma Process (멀티 플라즈마 공정을 이용한 하수 미생물의 불활성화)

  • Kim, Dong-Seog;Park, Young-Seek
    • Journal of Environmental Science International
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    • v.23 no.5
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    • pp.985-993
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    • 2014
  • For the field application of dielectric barrier discharge plasma reactor, a multi-plasma reactor was investigated for the inactivation of microorganisms in sewage. We also considered the possibility of degradation of non-biodegradable matter ($UV_{254}$) and total organic carbon (TOC) in sewage. The multi-plasma reactor in this study was divided into high voltage neon transformers, gas supply unit and three plasma modules (consist of discharge, ground electrode and quartz dielectric tube). The experimental results showed that the inactivation of microorganisms with treated water type ranked in the following order: distilled water > synthetic sewage effluent >> real sewage effluent. The dissolved various components in the real sewage effluent highly influenced the performance of the inactivation of microorganisms. After continuous plasma treatment for 10 min at 180 V, residual microorganisms appeared below 2 log and $UV_{254}$ absorbance (showing a non-biodegradable substance in water) and TOC removal rate were 27.5% and 8.5%, respectively. Therefore, when the sewage effluent is treated with plasma, it can be expected the inactivation of microorganisms and additional improvement of water quality. It was observed that the $NH_4{^+}$-N and $PO{_4}^{3-}$-P concentrations of sewage was kept at the constant plasma discharging for 30 min. On the other hand, $NO_3{^-}$-N concentration was increased with proceeding of the plasma discharge.

The effect of interfacial layer thickness on the interface dipole energy in $O_2$ plasma treated metal/organic interface

  • Kim, Soo-Young;Lee, Jong-Lam
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.115-117
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    • 2009
  • Interface dipole energies between interfacial layers with different thicknesses coated on indium tin oxides (ITOs) and 4,4'-bis[N-(1-naphtyl)-N-phenyl-amino]biphenyl are determined. After $O_2$ plasma treatment on thick-metal (>4 nm) coated ITO, the work function and interface dipole energy increased. In thin-metal (< 2 nm) coated ITO, no change in the interface dipole energy was found though the work function increased. Thus, the $O_2$ plasma treated thin (< 2 nm) interfacial layer reduced the hole injection barrier.

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Controlling Factors of Feed Intake and Salivary Secretion in Goats Fed on Dry Forage

  • Sunagawa, K.;Ooshiro, T.;Nakamura, N.;Nagamine, I.;Shiroma, S.;Shinjo, A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.10
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    • pp.1414-1420
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    • 2005
  • The purpose of this research was to determine whether or not feeding induced hypovolemia (decreases in plasma volume) and decreases in plasma bicarbonate concentration caused by loss of $NaHCO_3$ from the blood, act to suppress feed intake and saliva secretion volumes during the initial stages of feeding in goats fed on dry forage. The animals were fed twice a day at 10:30 and at 16:00 for 2 h each time. Prior to the morning feeding, the collected saliva (3-5 kg) was infused into the rumen. During the morning 2 h feeding period (10:30 to 12:30), the animals were fed 2-3 kg of roughly crushed alfalfa hay cubes. At 16:00, the animals were fed again with 0.8 kg of alfalfa hay cubes, 200 g of commercial ground concentrate and 20 g of sodium bicarbonate. In order to compensate for water or $NaHCO_3$ lost through saliva during initial stages of feeding, a 3 h intravenous infusion (17-19 ml/min) of artificial mixed saliva (ASI) or mannitol solution (MI) was begun 1 h prior to the morning feeding and continued until the conclusion of the 2 h feeding period. The physiological state of the goats in the present experiment remained unchanged after parotid gland fistulation. Circulating plasma volume decreases caused by feeding (estimated by increases in plasma total protein concentration) were significantly suppressed by the ASI and MI treatments. During the first 1 h of the 2 h feeding period, plasma osmolality in the ASI treatment was the same as the NI (non-infusion control) treatment, while plasma osmolality in the MI treatment was significantly higher. In comparison to the NI treatment, cumulative feed intake levels for the duration of the 2 h feeding period in the ASI and MI treatments increased markedly by 56.6 and 88.3%, respectively. On the other hand, unilateral cumulative parotid saliva secretion volume following the termination of the 2 h feeding period in the ASI treatment was 50.7% higher than that in the NI treatment. MI treatment showed the same level as the NI treatment. The results of the present experiment proved that the humoral factors involved in the suppression of feeding and saliva secretion during the initial stages of feeding in goats fed on dry forage, are feeding induced hypovolemia and decrease in plasma $HCO_3^-$ concentration caused by loss of $NaHCO_3$ from the blood.

Fabrication of soluble organic thin film transistor with ammonia ($NH_3$) plasma treatment

  • Kim, Dong-Woo;Kim, Doo-Hyun;Kim, Keon-Soo;Kim, Hyoung-Jin;Choi, Hong;Lee, Dong-Hyeok;Hong, Mun-Pyo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.566-567
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    • 2009
  • We have examined the silicon nitride ($SiN_x$) as gate insulator with the ammonia ($NH_3$) plamsa treatment for the soluble derivatives of polythiophene as p-type channel materials of organic thin film transistors (OTFTs). Fabrications of the jetting-processed OTFTs with $SiN_x$ as gate insulator by $NH_3$ plasma treatment can be similar to performance of OTFTs with silicon dioxide ($SiO_2$) insulator.

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Influence of Different Dietary Fats and Fat Unsaturation on Plasma Lipid Composition in Healthy Young Women (사람에서 식이지방의 불포화지방산과 불포화도가 혈장 지질조성에 미치는 영향)

  • 김채종;박현서
    • Journal of Nutrition and Health
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    • v.24 no.3
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    • pp.179-188
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    • 1991
  • Twenty college women were led experimental diet which composed ot basal diet plus different kinds of dietary rats at 27% Cal. Equal amount of 13.5g of corn oil, perilla oil or fish oil was supplied for 2 weeks as a source of n6 linoleic acid(LA). n3 $\alpha$-linolenic acid (LL). or n3 EPA + DHA. respectively. Plasma total Chol level was reduced by perilla and fish oils, significantly only by fish oil. Plasma Chol level was rather increased by corn oil(P<0.05), but was decreased by double amount of corn oil supplement. Therefore, hypocholesterolemic effect of fatty acids was in the order of n3 EPA+DHA>n3 LL>n6 LA and influenced by the degree of fat unsaturation. Plasma TG level was also significantly decreased by n3 EPA+ DHA and increased by n6 LA. Hypotriglyceridemic effect of fatty acids was also in the order of n3 EPA + DHA> n3 LL>n6 LA and influenced by the unsaturation. However, the reduction of plasma TG was more influenced by the fatty acid structure rather than the fat unsaturation. There were no significant effects on lipoprotein pattern 3nd chemical compositions of lipoprotein by different dietary PUFAs. but fish oil diet significantly increased the relative proportion of HDL-Chol. In conclusion. cholesterol- lowering effect of dietary PUFAS seemed to be a function of total fat unsaturation but hypotriglyceridemic effect seemed to be more linked to the ratty acid structure rather than the degree of unsaturation. The hypolipidemic effect of n3 PUFAs was significant so that fish oil or perilla oil may have important nutritional applications in the prevention and treatment of atherosclerotic disease.

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Effect of Plasma Treatment with O2, Ar, and N2 Gas on Porous TiO2 for Improving Energy Conversion Efficiency of DSSC (Dye Sensitized Solar Cell)

  • Gang, Go-Ru;Sim, Seop;Cha, Deok-Jun;Kim, Jin-Tae;Yun, Ju-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.202-202
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    • 2012
  • 염료감응태양전지(DSSC)의 광변환 효율을 향상시키기 위하여 진공챔버에서 450도 고온에서 O2, Ar, and N2 혼합가스를 주입하여 다양한 plasma로 TiO2 박막을 처리하면서 소성시켰다. TiO2 표면을 cleaning하고 활성화함으로서 염료의 결합력을 향상시키는 것 외에 TiO2 내부의 oxygen vacancy를 변화를 관찰하였다. 실험에 사용한 박막은 glass 위에 FTO 박막을 입히고, 다공성 TiO2 나노입자 박막을 코팅하여 제조하였다(porous TiO2 나노입자(${\sim}12{\mu}m$)/FTO(Fluorine doped Tin oxide; $1{\mu}m$)/glass). 완성된 광전극에 대해서 XRD, XPS, EIS, FE-SEM 등을 이용하여 분석하였다. 또한 이렇게 전처리된 광전극을 사용한 DSSC를 제작하였다. 그리고 Solar-simulator를 통해 그 효율을 측정하여 '플라즈마환경에서 소성된 광전극에 대한 DSSC의 광변환효율에 미치는 효과'을 고찰하였다.

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Effects of $N_2/H_2$ plasma treatments on enhancement of neuronal cell affinity on single-walled carbon nanotube paper scaffolds

  • Yoon, Ok-Ja;Lee, Hyun-Jung;Jang, Yeong-Mi;Kim, Hyun-Woo;Lee, Won-Bok;Kim, Sung-Su;Lee, Nae-Eung
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.393-393
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    • 2010
  • The biocompatibility of materials used for biomedical applications depends on chemical composition, mechanical stiffness, surface energy, and roughness. The plasma treatment and etching process is a very important technology in the biomedical fields due to possibility of controlling the surface chemistry and properties of materials. In this work, $N_2/H_2$ plasma were treated on single-walled carbon nanotubes (SWCNTs) paper and characterization of treated SWCNTs paper was carried out. Also we investigated neurite outgrowth from SH-SY5Y on treated SWCNTs paper. The results indicated that $N_2/H_2$ plasma-modified SWCNTs paper enhanced neuronal cell adhesion, viability, neurite outgrowth and branching in vitro and exerted a positive role on the health of neural cells.

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Deposition Characteristics of $TEOS-O_3$ Oxide Film on Substrate (기판 막질에 따른 $TEOS-O_3$ 산화막의 증착 특성)

  • Ahn, Yong-Cheol;Park, In-Seon;Choi, Ji-Hyeon;Chung, U-In;Lee, Jeong-Gyu;Lee, Jeong-Gyu
    • Korean Journal of Materials Research
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    • v.2 no.1
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    • pp.76-82
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    • 1992
  • Deposition of $TEOS-O_3$ oxide film as inter-metal dielectric layer shows the substrate dependency according to the substrate material and pattern density and pitch size. To minimize substrate and Pattern dependency, TEOS-base and $SiH_4-base$ Plasma oxide were predeposited as underlying material on the substrate. The substrate dependency of $TEOS-O_3$ oxide film was more significant on TEOS-base plasma oxide than on $SiH_4-base$ plasma oxide. The dependency of $TEOS-O_3$ oxide film was remarkably reduced, or nearly eliminated, by $N_2$plasma treatment on TEOS-base plasma oxide, which appears to be caused by the O-Si-N structure, observed on the the surface of TEOS-base plasma oxide.

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Adhesion Enhancement of Polyurethane Foam Using Atmospheric Plasma (II) (대기압 플라즈마를 이용한 폴리우레탄 소재의 접착력 향상 (II))

  • Sim, Dong Hyun;Seul, Soo Duk;Oh, Sang Taek
    • Journal of Adhesion and Interface
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    • v.8 no.3
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    • pp.1-8
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    • 2007
  • An atmospheric plasma pre-treatment method was applied to polyurethane foam to improve its contact angle and adhesion. In order to investigate the optimum reaction condition of plasma treatment, type of reaction gas (nitrogen, argon, oxygen, air), rate of gas flow (30~150 mL/min), and reaction time (0~30 sec) were examined in a plate plasma reactor. Also, the effects were compared to those of a conventional vacuum plasma pre-treatment system. The result of the surface modification with respect to the treatment procedure was characterized by using SEM and ATR-FTIR. Due to a decrease of the contact angle of polyurethane foam, the greatest adhesion strength was achieved at a flow rate of 100 mL/min and at a reaction time of 10s for N2 gas. Consequently, the atmospheric plasma treatment reduced the contact angle of the polyurethane foam and also resulted in the improvement of the peel strength.

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The Influence of Ar Gas in the Nitriding of Low Temperature Plasma Carburized AISI304L Stainless Steel. (AISI304L 스테인리스강의 저온 플라즈마 침탄처리 후 질화처리 시 Ar 가스가 표면 경화층에 미치는 영향)

  • Jeong, Kwang-ho;Lee, Insup
    • Korean Journal of Metals and Materials
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    • v.46 no.3
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    • pp.125-130
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    • 2008
  • Conventional plasma carburizing or nitriding for austenitic stainless steels results in a degradation of corrosion resistance. However, a low temperature plasma surface treatment can improve surface hardness without deteriorating the corrosion resistance. The 2-step low temperature plasma processes (the combined carburizing and post nitriding) offers the increase of both surface hardness and thickness of hardened layer and corrosion resistance than the individually processed low temperature nitriding and low temperature carburizing techniques. In the present paper, attempts have been made to investigate the influence of the introduction of Ar gas (0~20%) in nitriding atmosphere during low temperature plasma nitriding at $370^{\circ}C$ after low temperature plasma carburizing at $470^{\circ}C$. All treated specimens exhibited the increase of the surface hardness with increasing Ar level in the atmosphere and the surface hardness value reached up to 1050 HV0.1, greater than 750 $HV_{0.1}$ in the carburized state. The expanded austenite phase (${\gamma}_N$) was observed on the most of the treated surfaces. The thickness of the ${\gamma}_N$ layer reached about $7{\mu}m$ for the specimen treated in the nitriding atmosphere containing 20% Ar. In case of 10% Ar containing atmosphere, the corrosion resistance was significantly enhanced than untreated austenitic stainless steels, whilst 20% Ar level in the atmosphere caused to form CrN in the N-enriched layer (${\gamma}_N$), which led to the degradation of corrosion resistance compared with untreated austenitic stainless steels.