• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.209-212
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• 2001

Polyimide(PI) films have been considered as the interlayer dielectric materials due to low dielectric constant, low water absorption, high gap-fill and planarization capability. The PI mm Was etched with using inductively coupled plasma (ICP). The etching characteristics such as etch rate and selectivity were evaluated to gas mixing ratio. High etch rate was $8300{\AA}/min$ and vertical profile was approximately acquired $90^{\circ}$ at $CF_{4}/(CF_{4}+O_{2})$ of 0.2. The selectivies of polyimide to PR and $SiO_{2}$ were 1.2, 5.9, respectively. The etching profiles of PI films with an aluminum pattern were measured by a scanning electron microscope (SEM). The chemical states on the PI film surface were investigated by x-ray photoelectron spectroscopy (XPS). Radical densities of oxygen and fluorine in different gas mixing ratio of $O_{2}/CF_{4}$ were investigated by optical emission spectrometer (OES).

• Journal of Korean Vacuum Science & Technology
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• 제3권1호
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• pp.59-65
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• 1999

There has been an interest to develop an efficient, compact microwave device using field-emitter-arrays (FEA)-based cathode. Toe valuate the optimum device-efficiency in a compact size, the propagation properties of the premodulated electron beam for the FEA-based cathode is studied in detail by the computer simulation using a PIC code, MAGIC. For the premodulated electron beam whose phase of the energy leads the phase of the current by $\pi$/2, the amplitude of the downstream current modulation can be kept as high as the initial modulation level. Using the beam parameters with the beam voltage of 6kV and the current of 2.0A, 30% of efficiency is predicted when the quality factor of 800 is chosen. the device length is reduced about twice compared with that of the conventional device. The design of practical planar cathode is carried out to meet the minimum diameter of the electron beam as 0.5 mm.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.197-197
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• 2012

Device 제작에 사용된 graphene은 일반적인 lithography 공정에서 resist residue에 의한 오염을 피할 수 없으며 이로 인하여 graphene의 pristine한 성질을 잃어버린다. 본 연구에서는 graphene을 저밀도의 argon inductively coupled plasma (Ar-ICP)를 통해 처리함으로서 graphene based back-gated field effect transistor (G-FET)의 특성변화를 유도한 결과에 대해서 보고한다. Argon capacitively coupled plasma (Ar-CCP)은 에 노출된 graphene은 강한 ion bombardment energy로 인하여 쉽게 planar C-C ${\pi}$ bonding (bonding energy: 2.7 eV)이 breaking되어 graphene의 defect이 발생되었다. 하지만 우리의 경우 저밀도의 Ar-ICP가 적용될 때 graphene의 defect이 제한되며 이와 동시에 contamination 만을 제거할 수 있었다. 소자의 전기적 측정 (Gsd-Vbg)을 통하여 contamination으로 인하여 p-doping된 graphene은 pristine 상태로 회복되었으며 mobility도 회복됨이 확인되었다. Ar-ICP를 이용한 graphene cleaning 방법은 저온공정, 대면적 공정, 고속공정을 모두 만족시키며 thermal annealing, electrical current annealing을 대체하여 graphene 기반 소자를 생산함에 있어 쉽고 빠르게 적용할 수 있는 강점이 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2044-2046
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• 2000

A system to monitor the ion mass and charge-state as well as plasma potential value during plasma source ion implantation (PSII) has been developed. It was tested with 30-kV PI3D setup using alternatively hot cathode do (HC) and inductively coupled RF (ICP) discharge sources. The design and performance of the system will be described, and experimental results in nitrogen and argon plasmas produced by modular HC-ICP source will be discussed.

• 생명과학회지
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• 제32권10호
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• pp.762-770
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• 2022

제 2형 당뇨병은 고혈당을 특징으로 하는 만성 대사성 질환으로 인슐린 민감성및 저항성을 개선하여 세포속으로 포도당 흡수를 촉진시킴으로서 완화될 수 있다. 본 연구는 triterpenoid 화합물인 betulinic acid가 3T3-L1 지방세포에서 인슐린 신호전달체계를 개선하여 포도당 흡수를 촉진시키는지를 조사하고 그 작용기전을 규명하였다. Betulinic acid는 3T3-L1 지방세포에서 농도의존적으로 포도당 흡수를 유의하게 증가시켰으며, 이는 PM-GLUT4의 발현 증가와 관련이 있음을 관찰하였다. Betulinic acid는 인슐린 신호전달 경로에서 PI3K의 활성화 및 IRS-1tyr, Akt의 인산화를 대조군에 비해 유의하게 증가시켰다. 또한 AMPK의 활성화를 나타내는 pAMPK와 AMPK 하위인자인 pACC의 수준을 유의하게 증가시켰다. Betulinic acid에 의한 PI3K 및 AMPK 경로의 활성화를 증명하기 위해, PI3K 억제제(Wortmannin)와 AMPK의 억제제(Compound C)를 사용하여 이들 처리에 의한 포도당 흡수능과 PM-GLUT4의 발현을 측정한 결과 이들의 발현이 유의하게 저해되었다. 본 연구에서 betulinic acid는 3T3-L1 지방세포에서 PI3K 및 AMPK 경로의 활성화를 통해 세포막으로 포도당 수송체인 GLUT4 전위를 촉진시키고 포도당 흡수를 증가시킬 수 있음을 나타내었다. 이러한 결과는 betulinic acid가 인슐린 민감성을 증진시키고 고혈당을 완화하는데 도움이 될 수 있음을 시사한다.

• 마이크로전자및패키징학회지
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• 제19권3호
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• pp.77-82
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• 2012

본 연구에서는 칩을 기판에 내장하기 위해 상용화된 CSR사의 bluetooth chip을 이용하여 표면의 솔더볼을 제거하고 PCB소재와 공정을 이용하는 embedded active PCB 공정에 관한 연구를 하였다. 솔더볼이 제거된 칩과 PCB는 구리 도금 공정으로 연결되었으나 열 충격시 표면처리를 하지 않았을 시 칩의 표면과 ABF 간의 de-lamination 현상이 발견되었고, 이를 해결하기 위해 칩의 polyimide passivation layer에 디스미어와 플라즈마 공정을 이용하여 조도 형성을 하는 연구를 진행하였다. SEM(Scanning Electron Microscope) 과 AFM(Atomic Force Micrometer)을 통하여 표면을 관찰하였고, XPS(X-ray Photoelectron Spectroscopy)를 이용하여 표면의 화학적 구조의 변화를 관찰하였다. 실험결과 플라즈마 처리 시 표면 조도형성이 되었으나 그 밀도가 조밀하지 못하였지만 디스미어 공정과 함께 처리하였을 시 조도의 조밀도가 높아 열 충격을 가하였을 시에도 칩의 polyimide layer와 ABF간의 de-lamination 현상이 발견되지 않았다.

• Journal of Nutrition and Health
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• 제22권3호
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• pp.167-174
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• 1989

Vitamin B-2와 Vitamin B-6 결핍이 hematologic profile에 미치는 영향을 in vivo 계에서 알고보고자 하였다. 흰쥐에게 Vitamin B-2 결핍(-B2)식이, Vitamin B-6결핍(-B6)식이, Vitamin B-2와 Vitamin B-6복합 결핍(-B2-B6) 식이 또는 통제 식이를 6주 동안 공급한 후 희생시켜 Hematocrit (Ht), Hemoglobin(Hb), 혈장철 (PI), Transferrin포화도 (TS), 간장철 (LI)를 비교하였다. 통제군에 비하여 -B2군에서는 PI, TS, LI가 유의하게 낮았으나 Ht와 Hb은 유의한 차이가 없으며, -B6군에서는 Ht와 Hb는 유의하게 낮았으나 LI는 유의하게 높았다. 통제군에 비하여 -B2-B6군에서는 Hb, PI, TS, LI가 -B2군과 -B6군의 중간수준이었으며 Ht는 낮은 수준을 나타냈다. 2주간의 보충식이 후에는 -B2군과 -B6군에서 모든 혈액지표와 LI가 개선된 것으로 나타났다. 본연구의 결과는 Vitamin B-2와 Vitamin B-6의 섭취가 영양적 빈혈군에서 혈액 지표를 개선시켜 빈혈의 예방또는 치료에 중요하다는 것을 시사한다.

• 대한수의학회지
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• 제36권4호
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• pp.973-990
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• 1996

To investigate diagnostic imaging of cystitis and to apply it to the small animal practice, ultrasonogram of urinary bladder with moderate distension(4ml/kg) and with complete distension(9ml/kg) to evaluate the irregularity and thickness of bladder, radiography and histopathological examination were performed after experimental cystitis induction. On double contrast cystography, mucosal membrane of the urinary bladder was smooth and thickening urinary bladder wall was not found before cystitis induction. At 3rd day post induction(PI), mucosal irregularity was noted at the cranioventral region of the urinary bladder. Thickening of the urinary bladder wall and filling defect was observed as well. Cystographic findings of 7, 10, 15, 21 day PI were similar to that of 3rd day PI. On ultrasonographic findings of the mural thickness in induction group, it was ascertain that the mural thickness with moderate distention was more thickened than with complete distention at transverse scan. Ultrasonographic findings at longitudinal scan were similar to those of transverse scan. On ultrasonographic findings of mucosal irregularity in induction group, from PI to 7 day PI, mucosal irregularity with moderate distention was more irregular than mucosal irregularity with complete distention. At 10 day PI, there was similarity between moderate distention and complete distention. On histopathologic examination of a section of urinary bladder taken 3 day PI, the mucosal and submucosa were infiltrated by a mixture of thick inflammatory exudate which was composed of neutrophil, plasma protein, bacterial colony and necrotic cells. Congestion, hemorrhage and edema were also observed in the submucosa. At 7th day PI, the mucosal change was similar to that of 3rd day PI, but neovascularization and fibroplasia were observed in the submucosa. At 15th and 21th day PI, mild hyperplasia of mucosal epithelium was observed in the mucosa. Deposition of collagen, neovascularization and severe diffuse infiltration of lymphocyte were observed. These results suggest that ultrasonographic examination with moderate distention is considered to be a more simple, rapid, noninvasive, sensitive and useful diagnostic method than other diagnostic methods for the diagnosis of the cystitis and the differential diagnosis of urinary tract infection.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.254.1-254.1
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• 2014

Atmospheric plasma's electron temperature is less than thermal plasma, so it is useful at bio experiment. We have investigated the optical emission spectroscopy (OES) lines by spectrometer during Atmospheric plasma bombardment onto the PBS surface by using an Ar gas flow. Also we have measured the OH radical density inside the solution induced by the Atmospheric plasma bombardment. OH radical species are appeared at 308 nm and 309 nm. Densities of OH radical species has been found to be significantly decreased versus depth of the solution from 2 mm to 6 mm. OH radical density inside the PBS is measured to be about $1.87{\times}1016cm-3$ downstream at 2 mm from the surface under optimized Ar gas flow of 200 sccm in Atmospheric plasma. Also we have investigated cell viability of lung cancer and normal cell after Atmospheric plasma treatment for fixed exposure time in 60 seconds, but different depths. We used SEM, we observed change of cell morphorogy, did experiment about FDA & PI Staining method. It is found that there is selectivity between the lung cancer and lung normal cell, in which cancer cell definitely has higher cell death ratio more than normal cell. We have investigated change of bond structure in FT-IR spectroscopy, the following peaks were observed: and intense O-H peak at 3422 cm-1 and at 2925 cm-1 corresponds to C-H stretch vibrations of methylene group.

• 한국전기전자재료학회논문지
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• 제19권3호
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• pp.292-300
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• 2006

In order to improve energy efficiency in the dilute trichloroethylene removal using the nonthermal plasma process, the barrier discharge treatment combined with manganese dioxide was experimentally studied. Reaction kinetics in this process was studied on the basis of final byproducts distribution. Decomposition efficiency was improved to about $99\;\%$ at the specific energy of 40 J/L with passing through manganese dioxide. C=C ${\pi}$ bond cleavage of TCE substances gave DCAC, which has the single bond of C-C through oxidation reaction during the barrier discharge plasma treatment. Those DCAC were broken easily in the subsequent catalytic reaction due to the weak bonding energy about $3{\sim}4\;eV$ compared with the double bonding energy in TCE molecules. Oxidation byproducts of DCAC and TCAA from TCE decomposition are generated from the barrier discharge plasma treatment and catalytic surface chemical reaction, respectively. Complete oxidation of TCE into COx is required to about 400 J/L, but $CO_2$ selectivity remains about $60\;\%$.