• Title/Summary/Keyword: H2 Plasma

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Transport of space charge between sub-pixels in AC-plasma cell discharge

  • Lee, S.B.;Park, E.Y.;Han, Y.G.;Moon, M.W.;Oh, P.Y.;Song, K.B.;Lee, H.J.;Son, C.G.;Jeong, S.H.;Yoo, N.L.;Hong, Y.J.;Jeong, S.J.;Kim, J.H.;Park, S.O.;Choi, E.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.929-931
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    • 2006
  • In this experiment, we have investigated that the transported space charge between sub-pixels in AC-plasma cell discharge. The test pulse 30 V, $5{\mu}s$ was applied to the address electrodes of neighbor cells of discharge occurred cells. And we have measured the transported space charge between sub-pixels in accordance with the various last sustain pulse widths t(time gap between the rising edges of sustain and test pulses) of 0.2 to $3{\mu}s$. It was observed that the peak value of transported space charge has been shown to be 21.5pC at $1.0{\mu}s$. And the IR peak value have been occured after $0.51{\mu}s$ with respect to sustain voltage.

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The Relationships between Plasma Insulin-like Growth Factor (IGF)-1 and IGF-Binding Proteins (IGFBPs) to Growth Pattern, and Characteristics of Plasma IGFBPs in Steers

  • Lee, H.G.;Hidari, H.;Kang, S.K.;Hong, Z.S.;Xu, C.X.;Kim, S.H.;Seo, K.S.;Yoon, D.H.;Choi, Y.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.11
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    • pp.1575-1581
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    • 2005
  • This study was conducted to determine the characteristics of IGFBPs in plasma of steers, and to profile the relationship between growth and plasma IGF-1 and IGFBPs with aging in Holstein steers. Four blots of IGFBP at molecular weights of 38-43, 34, 29-32 and 24 kDa bands were detected by western ligand blot assay using $^{125}I-IGF-1$. On the basis of immunoblotting with anti-bovine IGFBP-2 and -3 antiserums, we observed the band for IGFBP-2 at approximately 34 kDa, and the IGFBP-3 band was detected at 38-43 kDa and 34 kDa in adult steers and calves. The IGFBP-3 antiserum used on the blots exhibited significant cross-reactivity with 34 kDa IGFBP-2. Furthermore, the 38-43 kDa IGFBP-3 bands were reduced to a 36 kDa band after deglycosylation, whereas the 34 kDa IGFBP-2 was intact. The plasma IGF-1, IGFBP-3 and other IGFBPs showed stability throughout a whole day. The change in live weight was found to be positively correlated to the plasma IGF-1 concentration (r = 0.6801, n = 64, p<0.05) and plasma IGFBP-3 (r = 0.6321, n = 64, p<0.05), while inversely correlated to plasma IGFBP-2 (r = -0.2919, n = 64, p<0.05). Furthermore, plasma IGF-1 was positively correlated to plasma IGFBP-3 (r = 0.6191, p<0.001), but was not correlated to plasma IGFBP-2. The portion of IGFBP-2 for total IGFBPs in calves was higher than in adult steers (p<0.05) and was decreased with growth, whereas that of IGFBP-3 was increased with increased live weight (p<0.05). The ratio IGFBP-3 for IGFBP-2 (BP-3/BP-2) was increased with growing of liveweight. Therefore, the changes in plasma IGF-1 level with increased liveweight may be related to the changes in plasma IGFBP-3 level and IGFBP-2 may give an important role in anabolic action of IGF-1 with the growth of body during calfhood in Holstein steers.

Plasma Catalytic Methane Conversion over Sol-gel Derived Pt/TiO2 Catalyst in a Dielectric-barrier Discharge Reactor (DBD 반응기에서 솔-젤 법으로 제조된 Pt/TiO2 촉매를 이용한 메탄의 플라즈마 전환반응)

  • Kim, Seung-Soo
    • Korean Chemical Engineering Research
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    • v.45 no.5
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    • pp.455-459
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    • 2007
  • Plasma catalytic methane conversion was carried out in the presence of sol-gel derived $Pt/TiO_2$ catalysts within a dielectric-barrier discharge (DBD) reactor. Plasma-assisted reduction (PAR) was applied to reduce the prepared $Pt/TiO_2$ catalysts in DBD reactor, and prepared catalysts were successively reduced by PAR within 20 min irrespective of the Pt loading and the calcination temperature. The highest methane conversion was 40% when 3 wt% $Pt/TiO_2$ and 5 wt% $Pt/TiO_2$ catalysts were used after calcination at $600^{\circ}C$. The selectivities of light alkanes ($C_2H_6$, $C_3H_8$, $C_4H_{10}$) were highly increased when $Pt/TiO_2$ catalysts were used in DBD reactor.

Dependence of the Formation of $TiO_{2\pm}{\delta}$ Films on Plasma Process Variables (플라즈마 공정 변수가 $TiO_{2\pm}{\delta}$ 박막 형성에 미치는 영향)

  • Park, Sang-Gi;Gang, Bong-Ju;Lee, Won-Hui;Lee, Jae-Gap
    • Korean Journal of Materials Research
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    • v.10 no.11
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    • pp.732-737
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    • 2000
  • Plasma enhanced chemical vapor deposition of $TiO_{2$\pm}{\delta}$ has been carried out using TEMAT [tetrakis(ethylmethylamido) titanium] and $H_2$. Increasing the power from 300 W to 500 W produced the high density plasma, leading to the formation of TiO$_2$films with an increased ratio of Ti to O and a negligible amount of C and N. Applying the bias of 30W to the substrate in creased the growth rate of the film with a slightly increased content of Ti in the film. In addition, $H_2O$ was from either the residual gas in the gase pressure or $H_2(/He)$ gas and actively participated in the formation of $TiO_2$ films. Consequently, Ti ions created in the plasma could be a main contributor to $TiO_2$ formation with a slight amount of $H_2O(~10^{-4}Toor)$ in the ambient, which provided the dissociation of TEMAT.

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Simplified HPLC Method for the Determination of Prazosin in Human Plasma and Its Application to Single-dose Pharmacokinetics

  • Gwak, Hye-Sun;Chun, In-Koo
    • Biomolecules & Therapeutics
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    • v.13 no.2
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    • pp.90-94
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    • 2005
  • Prazosin hydrochloride is an antihypertensive drug with selective ${\alpha}_1$-adrenoreceptor blocking effects. A simple high performance liquid chromatographic method has been developed and validated for the quantitative determination of prazosin in human plasma. A reversed-phase C18 column was used for the separation of prazosin and terazosin (internal standard) with a mobile phase composed of water, acetonitrile and triethylamine(75:25:0.1, V/V;pH5.0) at a flow rate of 1.5 ml/min. the fluorescence detector was set at excitation and emissionwavelengths of 250 and 370 nm, respectively. Intra-and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification of 0.5 ng/ml. Good recovery (>80%) was seen in plasma. Prazosin was stable in human plasma under various storage conditions. This method was used successfully for a pharmacokinetic study in plasma after oral administration of a single 2-mg dose as prazosin base to 16 healthy volunteers. The maximum plasma concentration of prazosin was 23.1 ${\pm}$ 16.5 ng/ml at 2.1 h, and the mean area under the curve and elimination half-life were calculated to be 108.4 ${\pm}$ 74.2 ng ${\cdot}$hr/ml and 2.5 ${\pm}$ 0.6 h, respectively.

An Experimental Study of Power Saving Technique in Non-thermal Plasma DeSOx/DeNOx Process (저온 플라즈마 탈황물질 공정의 운전전력 절감을 위한 실험연구)

  • 송영훈;최연석;김한석;신완호;길상인;정상현;최갑석;최현구;김석준
    • Journal of Korean Society for Atmospheric Environment
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    • v.12 no.4
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    • pp.487-494
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    • 1996
  • Simultaneous effects of $C_2H_4$ injection and heterogeneous chemical reactions on non-thermal plasma process to remove $SO_2$ and NOx from flue gas were investigated in the present experimental study. The present results showed that 40% of the electrical power can be reduced in $C_2H_4$ injection and heterogeneous chemical reaction are simultaneously included in the non-thermal plasma precess. As an effort to apply the non-thermal plasma technique to practical flue gas treatment system, a wire-plate type reactor which has technically similar geometry of industrial electrostatic precipitators is used instead of other types of reactors, such as wire-cylinder, packed-bed and surface discharge which are inappropriate to industrial application. In the present study, the photo pictures of positive streamer corona taken by ICCD camera, voltage and current oscillograms, and design criteria of a wire-plate type reactor are also shown, which are needed for industrial application of the non-thermal plasma process.

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Characteristics of $CH_4$ Decomposition by Plasma (플라즈마 이용 메탄 분해 특성)

  • Kim, Kwan-Tae;Lee, Dae-Hoon;Cha, Min-Suk;Ryu, Jeong-In;Song, Young-Hoon
    • Journal of the Korean Society of Combustion
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    • v.10 no.4
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    • pp.24-32
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    • 2005
  • Various types of plasma source applied in $CH_4$ decomposition process are compared. DBD by pulse and AC power, spark by pulse and AC power, rotating arc and hollow cathode plasma are chosen to be compared. The results show that $CH_4$ conversion per given unit power is relatively high in hollow cathode plasma and rotating arc that induces rather high temperature condition and that is why both thermal dehydration and plasma induced decomposition contribute for the overall process. In case of DBD wherein high temperature electron and low temperature gas molecule coexist, the process shows low conversion rate, for in rather low temperature condition the contribution of thermal dehydration is lowered. Selectivity of $C_2H_6$ and $C_2H_2$ is shown to be a good parameter of the relative contribution of plasma chemistry in the overall process. From the results we concluded that required condition of plasma source for a cost effective and high yield $CH_4$ decomposition is to have characteristics of both thermal plasma and non thermal plasma in which temperature is high above a certain threshold state for thermal dehydration and electron induced collision is maximized in the same breath.

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Surface Modification and Enzymatic Degradation of Microbial Polyesters by Plasma Treatments (플라즈마를 이용한 미생물합성 폴리에스테르의 표면개질과 효소분해성)

  • Kim, Jun;Lee, Won-Ki;Ryou, Jin-Ho;Ha, Chang-Sik
    • Journal of Adhesion and Interface
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    • v.7 no.2
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    • pp.19-25
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    • 2006
  • Since the enzymatic degradation of microbial poly(hydroxylalkanoate)s (PHAs), such as poly[(R)-3-hydroxybutyrate] and poly[(R)-3-hydroxybutyrate-co-3-hydroxyvalerate] initially occurs by a surface erosion process, their degradation behaviors can be controlled by the change of surface property. In order to control the rate of enzymatic degradation, plasma modification technique was applied to change the surface property of microbial PHAs. The surface hydrophobic and hydrophilic properties of PHA films were introduced by $CF_3H$ and $O_2$ plasma exposures, respectively. The enzymatic degradation was carried out at $37^{\circ}C$ in 0.1 M potassium phosphate buffer (pH 7.4) in the presence of an extracellular PHB depolymerase purified from Alcaligenes facalis T1. The results showed that the significant retardation of initial enzymatic erosion of $CF_3H$ plasma-treated PHAs was observed due to the hydrophobicity and the enzyme inactivity of the fluorinated surface layers while the erosion rate of $O_2$ plasma-treated PHAs was not accelerated.

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Fabrication of ITO/InP solar cells by employing H$_{2}$S plasma passivation technique (H$_{2}$S 플라즈마 passivation 방법을 응용한 ITO/InP 위성용 태양전지의 제작)

  • 이영철;한교용
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.1
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    • pp.59-65
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    • 1998
  • In order to simulataneously achieve surface type conversion and sulfur passivation of p-type InP, a Ha$_{2}$S plasma dry passivation technique was firstly proposed and successfully applied to the fabrication of ITO/InP solar cells. This new technique was expected to improve the performance of solar cells. The devices, fabricated by changing the process parameters such as RF power and plasma exposure time, were characterized and PL measurements were performed to investigate the passivation effects. As a result, H$_{2}$S plasma treated solar cells demonstrated better performance than that of (NH$_{4}$)$_{2}$S$_{x}$ treated ones.s.

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The Outgasing characteristics of MgO film for protecting layer of plasma display panel

  • Song, Byoung-Kwan;Lee, Young-Joon;Lee, Chang-Heon;Hwang, Hyun-Ki;Yeom, Guen-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.621-624
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    • 2002
  • In this study, outgassing characteristics of MgO films, and the plasma cleaning effects of the deposited MgO films by atmospheric pressure plasma on outgassing rate were compared. The MgO layer was heated up to 350 $^{\circ}C$ and the outgassing characteristics were observed for the heated conditions. As the main impurity species $H_2,\;H_2O,\;N_2,\;CO_2,\;and\;H_2O$ were released from this panel. Impurity species of plasma treatment panel were lower than non-treated panels for the heating temperature

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