• Title/Summary/Keyword: plasma $D_3$

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Initial state of GaN grown by plasma enhanced molecular beam epitaxy (PEMBE로 성장된 GaN 박막의 초기 거동 관찰)

  • Yi, Min-Su;Cho, Tae-Sik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.989-992
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    • 2004
  • PEMBE(plasma enhanced molecular beam epitaxy)방법으로 성장된 GaN 박막의 초기 거동현상을 실시간 X-선 산란을 이용하여 관찰하였다. 표면이 원자 계단(atomic step)을 이루고 있는 사파이어 기판 위에 성장하는 GaN 박막은 layer-by-layer 모드로 성장 후 3D 모드로 성장을 하였다. 거친 표면을 가진 사파이어 기판 위에 성장하는 GaN 박막은 성장 초기는 표면을 평평하게 만든 후, 3D 모드로 성장하였다. 플라즈마로 생성된 이온화된 질소는 표면의 에너지를 변화시켜 GaN 박막의 증착을 증진시키고, 표면의 coverage를 증가시킨다.

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Fibrinolytic and Anticoagulant Effects of Earthworm, Lumbricus rubellus, Extracts (구인(Lumbricus rubellus) 추출물의 혈전 분해 및 항혈전 효과)

  • 장정순;이철규;신장식;조일환;서정진
    • YAKHAK HOEJI
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    • v.39 no.6
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    • pp.666-670
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    • 1995
  • The plasmin activity of euglobulin fraction treated with earthworm extract(EWE) increased concentration dependently when EWE(0.5, 1.0 and 2.0 mg each) were added to normal plasma. It was shown that lumbrokinase in EWE may be moved to euglobulin fraction and activated plasminogen. Also anticoagulation and fibbrinolysis were studied when EWE(7.5, 30 and 120 mg/kg) were added to rat model. Prothrombin time (PT) were 19.7${\pm}$ 3.8, 22.5${\pm}$ 2.5 and 24.5${\pm}$ 5.0sec. activated partial thromboplastin time (APTT) were 25.7${\pm}$ 5.9, 28.7${\pm}$ 5.2 and 36.5${\pm}$ 19.1 sec. After 15 days, the production of D-dimer were 242.3${\pm}$ 47.4, 250.0${\pm}$ 11.9 and 205.8${\pm}$ 12.2mg/ml plasma, respectively. These data showed that EWE acted on the coagulation factor of intrinsic and extrinsic system.

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New LEDs improve the quality of illumination of full-color holograms recorded with red 660 nm, green 532 nm and blue 440 nm lasers

  • Gentet, Philippe;Gentet, Yves;Joung, Jinbeom;Park, Sungchul;Park, Misoo;Lee, Seunghyun
    • International Journal of Advanced Culture Technology
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    • v.7 no.4
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    • pp.274-282
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    • 2019
  • This paper discusses the main requirements in today's full-color holograms illumination and evaluates the last generation of LEDs, the actual best light source to render properly the colors of the holograms and in particular those recorded with red 660 nm, green 532 nm and blue 440 nm lasers. This paper presents also the first prototype of lamp designed especially for this kind of holograms.

Numerical Modeling of Very High Frequency Multi Hollow Cathode PECVD (Very High Frequency Multi Hollow Cathode PECVD 장치의 수치모델링)

  • Joo, Jung-Hoon
    • Journal of the Korean Vacuum Society
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    • v.19 no.5
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    • pp.331-340
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    • 2010
  • 3D fluid based numerical modelling is done for a VHF multi hollow cathode array plasma enhanced chemical vapor deposition system. In order to understand the fundamental characteristics of it, Ar plasma is analyzed with a condition of 40 MHz, 100 Vrf and 1 Torr. For hole array of 6 mm diameter and 20 mm inter-hole distance, plasma is well confined within the hole at an electrode gap of 10 mm. The peak plasma density was $5{\times}10^{11}#/cm^3$ at the center of the hole. When the substrate was assumed at ground potential, electron temperature showed a peak at the vicinity of the grounded walls including the substrate and chamber walls. The reaction rate of metastable based two step ionization was 10 times higher than the direct electron impact ionization at this condition. For $H_2$, the spatial localization of discharge is harder to get than Ar due to various pathways of electron impact reactions other than ionization.

The Properties of Microwave Propagation in Discharging Plasma (방전에 의한 프라즈마에서의 마이크로파 전파특성)

  • Yang, In-Eung;No, Bang-Hyeon;Kim, Bong-Yeol
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.5 no.3
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    • pp.31-39
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    • 1968
  • In this paper microwave power propagated through the cold plasma was analyzed and measured with respect to the external magenetic flux density. The d. c discharge plasma was in the rectangular waveguide in which two electrode was inserted, and also the glass diseharge tube inserted in the ractangular wavegside. The direction of microwave pro-pagation, the axis of the discharge tube and external magnetic flux were perpendicular to each other. It showed that the attenuation and absorption of micro wave power propagated in the plasma was increased as the magnetic flux density, the discharge current and the pressure of the gas were increased.

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Analysis of Energy and Ground Vibration of Plasma Blasting (플라즈마 발파의 폭력과 지반진동특성)

  • 이경운;박철환;신중호;류창하
    • Tunnel and Underground Space
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    • v.7 no.4
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    • pp.267-273
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    • 1997
  • Rock fragmentation with plasma blasting technique has advantageous properties in contrast to the conventional blasting method in controlling of flying rocks and ground vibrations, when residents are complaining or surrounding structures stay in protection from blasting operations. The experiences show in urban construction works that the plasma blasting is the most possible method to prevent damages and minimize adverse environmnetal impacts. The fragmentation energy level is evaluated by numerical simulation using PFC-2D for various drill hole pattern and tested accordingly to get the feasibility. The energy output of plasma blasting system has been improved to a level of 1 MJ, which can break a 2~3 ㎥ granite boulder or 1.5 m height bench face. Measurements are carried out to get the ground vibration level and propagation equation, so that the control of the blasting operations can be performed more precisely and safely.

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A study on the relationships between plasma parameters and magnetic field (플라즈마 파라메타와 자계의 상관관계에 관한 연구)

  • 김두환;장윤석;조정수;박정후
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.3
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    • pp.426-431
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    • 1996
  • It is well known that the understanding of the complex mechanism of magnetoplasma is closely related with understanding of the collective behavior of discharge plasma parameters such as the cathode-sheath potential, cathode-sheath thickness, electron temperature, electron density, and ambipolar diffusion. In this paper, some of the relationships between these plasma parameters and magnetic field is investigated experimentally with a Langmuir probe in the magnetoplasma generated by D.C diode system. It is found that when magnetic field is increased, cathode-sheath potential, cathode-sheath thickness, and ambipolar diffusion are decreased. In addition, peak ion density obtained as a parameter of ionic signal voltage by Faraday cup method is independent of magnetic field. (author). 9 refs., 11 figs.,1 tab.

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Effect of cinacalcet-mediated parathyroid hormone reduction on vitamin D metabolism in high-fat diet-induced obese mice

  • Tae Yeon Kim;Chan Yoon Park;Sung Nim Han
    • Journal of Nutrition and Health
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    • v.56 no.1
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    • pp.1-11
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    • 2023
  • Purpose: Obesity is associated with alterations in vitamin D metabolism and elevation of parathyroid hormone (PTH). Increased PTH level in obesity is likely one of the factors contributing to the dysregulation of vitamin D metabolism. We investigated the effects of lowering the PTH level in high-fat diet-induced obese mice on vitamin D metabolism. Methods: Five-week-old male C57BL/6N mice were fed either with control (10% energy as fat) or high-fat (60% energy as fat) diets ad libitum for 12 weeks, and vehicle or cinacalcet HCl (30 ㎍/g body weight) was gavaged daily during the final week of the experiment. The following groups were studied: CON (control diet + vehicle), HFD (high-fat diet + vehicle), and HFD-CIN (high-fat diet + cinacalcet HCl). PTH, 1,25-dihydroxyvitamin D (1,25[OH]2D), 25-hydroxyvitamin D (25[OH]D), calcium, and phosphate levels in circulation, and the expression of genes related to vitamin D metabolism in the liver and kidneys were determined. Results: Renal 1α-hydroxylase expression in the HFD group was higher than that in the CON group despite the lack of a difference in the PTH levels between the 2 groups. The plasma PTH level in the HFD-CIN group was 60% lower than that in the HFD group (p < 0.05). In parallel, the HFD-CIN group had lower adipose tissue amount (9% lower), renal 1α-hydroxylase expression (48% lower), and plasma 1,25(OH)2D concentration (38% lower) than the HFD group. Conclusion: Lowering the PTH levels in high-fat diet-induced obese mice recovered the expression of renal 1α-hydroxylase and might be associated with lower amounts of white adipose tissue.

Microsatellite Alterations of Plasma DNA in Non Small Cell Lung Cancer (비소세포폐암 환자의 혈장 DNA를 이용한 Microsatellite 분석)

  • Kim, Kyu-Sik;Kim, Eun-Jung;Kim, Soo-Ock;Oh, In-Jae;Park, Chang-Min;Jeong, Ju-Yeon;Kim, Yu-Il;Lim, Sung-Chul;Park, Jong-Tae;Kim, Young-Chul
    • Tuberculosis and Respiratory Diseases
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    • v.58 no.4
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    • pp.352-358
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    • 2005
  • Microsatellites are short tandem repeated nucleotide sequences that are present throughout the human genome. Variations in the repeat number or a loss of heterozygosity around the microsatellites have been termed a microsatellite alteration (MA). A MA reflects the genetic instability caused by an impairment in the DNA mismatch repair system and is suggested to be a novel tumorigenic mechanism. A number of studies have reported that MA in the DNA extracted from the plasma occurs at varying frequencies among patients with a non-small cell lung carcinoma (NSCLC). The genomic DNA from 9 subjects with a non-small cell lung cancer (squamous cell cancer 6, adenocarcinoma 2, non-small cell lung cancer1) and 9 age matched non-cancer control subjects (AMC: tuberculosis 3, other inflammatory lung disease 6) and 12 normal control subjects (NC) were extracted from the peripheral blood leukocytes and plasma. Three microsatellite loci were amplified with the primers targeting the Gene Bank sequence D21S1245, D3S1300, and D3S1234. MA in the form of an allelic loss or a band shift was examined with 6% polyacrylamide gel electrophoresis and silver staining. None (0/12) of the NC subjects less than 40 years of age showed a MA in any of the three markers, while 88.9%(8/9) of the AMC above 40 showed a MA in at least one of the three markers (p<0.05). Sixty percent(6/10) of the control subjects with a smoking history showed a MA in one of the three markers, while 9.1%(1/11) of the control subjects without smoking history showed a MA (p<0.05). However, not only did 66.7%(6/9) of lung cancer patients show a MA in at least one of the three markers but so did 88.9%(8/21) of the AMC patients (p>0.05). In conclusion, a MA in the D21S1245, D3S1300, and D3S1234 loci using DNA extracted from the plasma was detected in 66.7% of lung cancer while no MA was found in the young non-smoking control subjects. However, many of the non-cancer control subjects (aged smokers) also showed a MA, which compromised the specificity of the MA analysis as a screening test. Therefore, a further study with a larger sample size will be needed.

Fast response time PDP phosphors for 3D display application

  • Song, Jay-Hyok;Song, Yu-Mi;Kim, Ji-Hyun;Kim, Min-Ju;Kim, Ji-Hyun;Kwon, Seon-Young;Park, Do-Hyung;Kim, Yoon-Chang;Zang, Dong-Sik
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1255-1258
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    • 2008
  • New phosphors that enable the 3D application of PDP have been developed The decay times of $Y_3Al_5O_{12}:Ce^{3+}$, $(Y,Gd)Al_3(BO_3)_4:Tb^{3+}$ and $(Y,Gd)_2O_3:Eu^{3+}$ were extremely shorter than those of conventional PDP phosphors. The color coordinates and intensities of the phosphors were also suitable for PDP For the first time in PDP industry, 3D/2D switchable PDP has been commercially available by adopting the phosphors.

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