• Title/Summary/Keyword: Plasma

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The comparative study of pure and pulsed DC plasma sputtering for synthesis of nanocrystalline Carbon thin films

  • Piao, Jin Xiang;Kumar, Manish;Javid, Amjed;Wen, Long;Jin, Su Bong;Han, Jeon Geon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.320-320
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    • 2016
  • Nanocrystalline Carbon thin films have numerous applications in different areas such as mechanical, biotechnology and optoelectronic devices due to attractive properties like high excellent hardness, low friction coefficient, good chemical inertness, low surface roughness, non-toxic and biocompatibility. In this work, we studied the comparison of pure DC power and pulsed DC power in plasma sputtering process of carbon thin films synthesis. Using a close field unbalanced magnetron sputtering system, films were deposited on glass and Si wafer substrates by varying the power density and pulsed DC frequency variations. The plasma characteristics has been studied using the I-V discharge characteristics and optical emission spectroscopy. The films properties were studied using Raman spectroscopy, Hall effect measurement, contact angle measurement. Through the Raman results, ID/IG ratio was found to be increased by increasing either of DC power density and pulsed DC frequency. Film deposition rate, measured by Alpha step measurement, increased with increasing DC power density and decreased with pulsed DC frequency. The electrical resistivity results show that the resistivity increased with increasing DC power density and pulsed DC frequency. The film surface energy was estimated using the calculated values of contact angle of DI water and di-iodo-methane. Our results exhibit a tailoring of surface energies from 52.69 to $55.42mJ/m^2$ by controlling the plasma parameters.

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Fluxless Plasma Soldering of Pb-free Solders on Si-wafer -Effect of Plasma Cleaning - (Si-wafer의 플럭스 리스 플라즈마 무연 솔더링 -플라즈마 클리닝의 영향-)

  • 문준권;김정모;정재필
    • Journal of the Microelectronics and Packaging Society
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    • v.11 no.1
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    • pp.77-85
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    • 2004
  • To evaluate the effect of plasma cleaning on the soldering reliability the plasma cleaning using Ar-10vol%$H_2$ gas was applied on a UBM(Under Bump Metallization). The UBM consisted of Au/ Cu/ Ni/ Al layers which were deposited on a Si-wafer with 20 nm/ 4 $\mu\textrm{m}$/ 4 $\mu\textrm{m}$/ 0.4 $\mu\textrm{m}$ thickness respectively. Sn-3.5%Ag, Sn-3.5%Ag-0.7%Cu and Sn-37%Pb solder balls sized of 500 $\mu\textrm{m}$ in diameter were used. Solder balls on the UBM were plasma reflowed under Ar-10%$H_2$ plasma (with or without plasma cleaning). They were compared with air reflowed solder balls with flux. The spreading ratios of plasma reflowed solder with plasma cleaning was 20-40% higher than that of plasma reflowed solder without plasma cleaning. The shear strength of plasma reflowed solder with plasma cleaning was about 58-65MPa. It showed 60-80% higher than that of plasma reflowed solder without plasma cleaning and 15-35% higher than that of air reflowed solder. Thus it was believed that plasma cleaning for the UBM using Ar-10vol%$H_2$ gas was considerably effective for the improvement of the strength of solder ball.

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Effect of Artemisia Capillaris Thunberg EtOH Ext. on Lowering Lipid, Anti-oxidation and Concentration of Plasma Inflammatory Mediators Using Rats Fed on High-oxidized Fat (인진호(茵蔯蒿) 추출물이 과산화지질 투여한 쥐의 지질강하, 항산화효과 및 염증매개물질의 생산에 미치는 영향)

  • Kong, In-Pyo;Lee, Eun;Cha, Yun-Yeop
    • Journal of Korean Medicine Rehabilitation
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    • v.21 no.1
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    • pp.23-33
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    • 2011
  • Objectives : The present study investigated effects of Artemisia Capillaris Thunberg ethanol extract(EtOH ext). on lowering lipid, anti-oxidation and concentration of plasma inflammatory mediators using rat fed on high oxidized fat. Methods : We divided fat sprague-dawley rats fed on high oxidized into 4 groups. They were normal group, feed with 100 mg/kg Artemisia Capillaris Thunberg group, feed with 200 mg/kg Artemisia Capillaris Thunberg group and feed with 300 mg/kg Artemisia capilaris Thunberg group. They were administered for 4 weeks. We measured concentration of plasma free fatty acid(FFA), plasma triglyceride, plasma total cholesterol, and plasma low density lipoprotein-cholesterol(LDL-cholesterol), plasma high density lipoprotein-cholesterol(HDL-cholesterol), concentration of liver total cholesterol and liver triglyceride (TG), concentration of plasma thiobarbituric acid reactive substance(TBARS) and liver thiobarbituric acid reactive substance(TBARS), glutathione peroxidase (GSH-Px) activity, superoxide dismutase(SOD) activity and catalase(CAT) activity, plasma nitric oxide(NO), ceruloplasmin and ${\alpha}-glycoprotein$. Results : 1. The Artemisia Capillaris Thunberg EtOH ext. groups showed low concentration of plasma FFA, plasma triglyceride, plasma total cholesterol and plasma LDL-cholesterol compared to control group. However, concentration of plasma HDL-cholesterol was increased in the Artemisia Capillaris Thunberg EtOH ext. groups. 2. Concentration of liver total cholesterol and liver TG showed a significantly decrement in all Artemisia Capillaris Thunberg EtOH ext. groups than that of control group. 3. The Artemisia Capillaris Thunberg EtOH ext. groups showed lower values in concentration of plasma TBARS and liver TBARS than that of control group. The values of GSH-Px activity, SOD activity and CAT activity were increased in the Artemisia Capillaris Thunberg EtOH ext. groups. 4. The values of plasma NO, ceruloplasmin and ${\alpha}-glycoprotein$ were decreased in Artemisia Capillaris Thunberg EtOH ext. groups. Conclusions : Based on the results in this study, the Artemisia Capillaris Thunberg EtOH ext. showed a positive effect in lowering lipid, anti-oxidation and decrement of plasma inflammatory mediators.

Plasma Medicine: How can Nonthermal Atmospheric Plasma be Applied to Medicine? (플라즈마 메디신: 저온 상압 플라즈마는 어떻게 의학분야에 적용될 수 있는가?)

  • Park, Sang Rye;Hong, Jin Woo;Lee, Hae June;Kim, Gyoo Cheon
    • Journal of Life Science
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    • v.23 no.6
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    • pp.838-846
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    • 2013
  • As a forth state of material, plasma is ionized gas, which generates characteristically various reactive species. After late of $20^{th}$ century, plasma has been widely used in industry. After nonthermal atmospheric plasma was developed, it has been applied to biomedical fields. Nonthermal atmospheric plasma does not give thermal damages to human tissues, and it shows the high efficiency in cancer treatment, sterilization, tooth bleaching, coagulation, and wound healing. Because the application of plasma to biomedicine has been expanded through interdisciplinary studies, its value of high medical technology is increasing now. Since nonthermal atmospheric plasma was first applied to the mammalian cells and microorganisms, many valuable studies has been performed for about last 10 years, so that now the new research area called 'plasma medicine' has been formed. This article introduces the recent data resulted from plasma medicine and helps to understand the plasma medicine.

Optimization of Air-plasma and Oxygen-plasma Process for Water Treatment Using Central Composite Design and Response Surface Methodology (중심합성설계와 반응표면분석법을 이용한 수처리용 산소-플라즈마와 공기-플라즈마 공정의 최적화)

  • Kim, Dong-Seog;Park, Young-Seek
    • Journal of Environmental Science International
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    • v.20 no.7
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    • pp.907-917
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    • 2011
  • This study investigated the application of experimental design methodology to optimization of conditions of air-plasma and oxygen-plasma oxidation of N, N-Dimethyl-4-nitrosoaniline (RNO). The reactions of RNO degradation were described as a function of the parameters of voltage ($X_1$), gas flow rate ($X_2$) and initial RNO concentration ($X_3$) and modeled by the use of the central composite design. In pre-test, RNO degradation of the oxygen-plasma was higher than that of the air-plasma though low voltage and gas flow rate. The application of response surface methodology (RSM) yielded the following regression equation, which is an empirical relationship between the RNO removal efficiency and test variables in a coded unit: RNO removal efficiency (%) = $86.06\;+\;5.00X_1\;+\;14.19X_2\;-\;8.08X_3\;+\;3.63X_1X_2\;-\;7.66X_2^2$ (air-plasma); RNO removal efficiency (%) = $88.06\;+\;4.18X_1\;+\;2.25X_2\;-\;4.91X_3\;+\;2.35X_1X_3\;+\;2.66X_1^2\;+\;1.72X_3^2$ (oxygen-plasma). In analysis of the main effect, air flow rate and initial RNO concentration were most important factor on RNO degradation in air-plasma and oxygen-plasma, respectively. Optimized conditions under specified range were obtained for the highest desirability at voltage 152.37 V, 135.49 V voltage and 5.79 L/min, 2.82 L/min gas flow rate and 25.65 mg/L, 34.94 mg/L initial RNO concentration for air-plasma and oxygen-plasma, respectively.

Analysis of Trace Level and Correlation of Lead in the Plasma of Field Workers and General Public by ICP-MS (유도결합플라즈마 질량분석법에 의한 납 취급 근로자와 일반인의 혈장 중 납 분석 및 상관성 분석)

  • Lee, Sung-Bae;Yang, Jeong-Sun;Choi, Sung-Bong;Kim, Nam-Soo;Lee, Byung-Kook;Shin, Ho-Sang
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.23 no.2
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    • pp.65-74
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    • 2013
  • Objectives: This study attempted to develop a method to measure ultra-trace lead concentrations in plasma using Inductively Coupled Plasma Mass Spectrometry(ICP-MS) and to test whether plasma lead can be used as a biomarker for the biological monitoring of exposure to lead. Methods: Lead concentrations in 160 plasma samples of field workers and 42 plasma samples from the control group were measured by ICP-MS. Blood zinc protophorphyrin(ZPP) concentrations and urinary ${\delta}$-aminolevulinic acid${\delta}-ALA$) were measured for correlation analysis with plasma lead. Results: The mean lead level in the plasma of the workers exposed to lead at work were 786.1 ng/L. Plasma lead levels were not correlated with blood ZPP or urinary ${\delta}-ALA$ concentrations. Otherwise, plasma lead levels showed a good correlation coefficient of 0.400 with blood lead levels, and their correlation coefficient had a better value of 0.552 for the non-smoking and drinking group. In the general population group which was not exposed to lead in the workplace and was considered the control group, the mean concentration of plasma lead was 123.1 ng/L. The plasma lead levels for the general population group showed a good correlation coefficient of 0.520 with blood ZPP and urinary ${\delta}-ALA$ concentrations.

Antioxidant Status and its Relationship to Plasma Cytokine Levels in Korean Elderly Women Living in Seoul

  • Kim, Mi-Joung;Kim, Jung-Hee
    • Journal of Community Nutrition
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    • v.6 no.2
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    • pp.103-109
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    • 2004
  • Body antioxidant status is an important factor for the prevention of many chronic diseases in the elderly. This study was done to investigate antioxidant status and its relationship to immune response by measuring plasma cytokine (IL-2 and IL-6) levels in elderly women. Subjects were 76 elderly women aged over 60 years, visiting Jangwhi Social Welfare Center of Seongbook-Gu in Seoul. Subjects were divided into 3 groups according to age (< 65, 65 - 74, > 75). Dietary intakes were assessed by semi-quantitative food frequency questionnaires (SFFQ). Plasma vitamin C level was measured by 2,4-dinitrophenylhydrazine method and plasma levels of vitamin E, A and ${\beta}$-carotene were measured by HPLC. Plasma levels of IL-2 and IL-6 were determined with a solid phase sandwich enzyme linked-immuno-sorbent assay (ELISA) using commercial kits. The average intakes of antioxidant vitamins were 96.3mg (137.5% of RDA) for vitamin C and 523.3 ${\mu}$gRE (74.8% of RDA) for vitamin A in elderly women. All of the average plasma levels of antioxidant vitamins were within normal range. However the percentage of the elderly women with deficiency plus marginal values were 7.9% in vitamin C, 9.2% in vitamin A and 7.9% in vitamin E. Plasma levels of IL-2 and IL-6 were 27.1${\pm}$7.1pg/ml and 5.9${\pm}$5.3pg/ml in elderly women. Correlation data showed that plasma IL-2 level was negatively correlated with plasma vitamin C level. In addition, IL-6 level was also negatively correlated with plasma vitamin C, A and E levels, respectively. There was a significant positive correlation between erythrocyte thiobarbituric acid-reactive substance(TB-ARS) level and plasma IL-2 or IL-6 levels. In addition, erythrocyte TBARS level showed a significant positive correlation with plasma total antioxidant status (TAS) level and a significant negative correlation with plasma vitamin C level. Overall results might imply that the decreased levels of antioxidant vitamins result in an increase in oxidative stress and thereby increase cytokine production such as IL-2 and IL-6. However further research is required to elucidate these relationships.