• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.39.1-39.1
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• 2009

본 실험은 연성과 광 투명도가 뛰어난 아크릴 (PMMA) 과 폴리카보네이트 (Polycabonate) 기판의 축전 결합형 플라즈마 (CCP) 건식 식각 연구에 관한 것이다. 특히 식각 반응기 내부의 압력 변화에 따른 두 기판의 건식 식각 특성 분석에 초점을 맞추었다. 실험에 사용된 기판은 두께 1mm의 아크릴 (PMMA) 과 폴리카보네이트 (Polycabonate)를 $1.5\times1.5\;cm^2$로 절단하여 Photo-lithography 공정을 통하여 감광제 (Photo-resist)로 패턴하였다. 식각 반응기 내부에 패턴 된 아크릴(PMMA) 과 폴리카보네이트 (Polycabonate)를 넣은 후 반응기 내부 진공 상태로 만들었다. 그 후 5 sccm $O_2$ 가스를 유량조절기 (Mass flow controller)를 통하여 식각 반응기 내부로 유입하여 실험을 하였다. 이때 식각 공정 변수는 식각 반응기 내부 압력과 샘플 척 파워이다. 특성평가 항목은 식각 후 기판 (Substrate)의 식각율 (Etch rate), 식각 선택비 (Selectivity) 그리고 기판 표면 거칠기 (RMS roughness)이다. 실험 결과는 표면 단차 분석기(Surface profiler)를 이용하여 기판 (Substrate)의 표면을 분석 하였다. 또한 OES (Optical Emission Spectroscopy) 를 이용하여 식각 중 내부 플라즈마의 상태를 분석하였다. 본 실험 결과에 따르면 5 sccm $O_2$ 가스와 100 W 척 파워를 고정한 후 반응기 내부의 압력을 25 mTorr에서 180 mTorr까지 변화시켜 실험한 결과 40 mTorr의 반응기 내부 압력에서 실험 자료 중 가장 높은 식각율로 아크릴 (PMMA)은 $0.46\;{\mu}m/min$, 폴리카보네이트 (Polycabonate)는 $0.28\;{\mu}m/min$의 결과를 얻었다. 또한 이 자료를 바탕으로 5 sccm $O_2$ 가스와 반응기 내부 압력을 40 mTorr로 고정시키고 RIE 척 파워를 25 W에서 150 W로 증가시켰을 때 아크릴 (PMMA)의 식각율은 $0.15\;{\mu}m/min$에서 $0.72\;{\mu}m/min$까지 증가하였고, 폴리카보네이트 (Polycabonate) 의 식각율은 $0.1\;{\mu}m/min$에서 $0.36\;{\mu}m/min$까지 증가하였다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.151-155
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• 2005

Though the nuclear fusion system has been fused into hydro-nuclear based on thermodynamics by tokamak system, there has been no success story. Because it's impossible to confine high temperatured plasma long Time actually. New nuclear-fusion-system using this nuclear-fusion-method will gather toroidal-magnetic-field by putting Core Block(C shaped torus iron) and toroidal-aluminium coil into toroidal magnetic-field-aluminium. That will arrange the nuclear-fusion-route on a gap fallen out by a part of cut torus-core and mkee the toroidal-an electric-current flow and electrolyze the fusioned-material (an electrolyte) into troidal-electrocity. That consists of troidal-magnetic-fild coil, toroidal-coial fusioned- material, series circuit. So toroidal-electocity will be changed into filament-electrocity and be introjected into fusioned-material. In a sapce on filament-electrocity, the magnetic inhaling-powr will enlarge to input-electrocity outside. This will exceed the Coulomb force and reache the nuclear-fusion. By this phenomenon there be quantity-loss. By this process I could confirmed that Einstein euation$(E=mC^2)$ releases into thermal energy.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1317-1325
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• 2008

Viral safety is an important prerequisite for clinical preparations of plasma-derived pharmaceuticals. One potential way to increase the safety of therapeutic biological products is the use of a virus-retentive filter. In order to increase the viral safety of human antihemophilic factor IX, particularly in regard to non-enveloped viruses, a virus removal process using a polyvinylidene fluoride membrane filter (Viresolve NFP) has been optimized. The most critical factor affecting the filtration efficiency was operating pH and the optimum pH was 6 or 7. Flow rate increased with increasing operating pressure and temperature. Recovery yield in the optimized production-scale process was 96%. No substantial changes were observed in the physical and biochemical characteristics of the filtered factor IX in comparison with those before filtration. A 47-mm disk membrane filter was used to simulate the process performance of the production-scale cartridges and to test if it could remove several experimental model viruses for human pathogenic viruses, including human hepatitis A virus (HAV), porcine parvovirus (PPV), murine encephalomyocarditis virus (EMCV), human immunodeficiency virus type 1 (HIV), bovine viral diarrhea virus (BVDV), and bovine herpes virus (BHV). Non-enveloped viruses (HAV, PPV, and EMCV) as well as enveloped viruses (HIV, BVDV, and BHV) were completely removed during filtration. The log reduction factors achieved were $\geq$6.12 for HAV, $\geq$4.28 for PPV, $\geq$5.33 for EMCV, $\geq$5.51 for HIV, $\geq$5.17 for BVDV, and $\geq$5.75 for BHV. These results indicate that the virus filtration process successfully improved the viral safety of factor IX.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.1
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• pp.58-64
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• 2020

This present study was conducted to investigate protective effect of discontinuous Percoll gradient containing alpha-linolenic acid (ALA) before freezing process on viability, acrosome damage, mitochondrial activity, and oxidative stress of frozen-thawed boar spermatozoa. The separation of spermatozoa by discontinuous Percoll gradient was performed by different concentration of Percoll solution (45/90%) containing ALA combined with bovine serum albumin (BSA), and collected sperm in each Percoll layer was cryopreserved. To evaluate viability, acrosome damage, mitochondrial activity, and reactive oxygen species (ROS) level of frozen-thawed sperm, flow cytometry was used. Morphological abnormalities were observed under light microscope. In results, viability of sperm from 90% Percoll layer was higher than control and 45% Percoll group (p < 0.05). Separated sperm in 90% Percoll layer had lower acrosome damage and morphological abnormalities than control as well as viability, whereas 45% Percoll group was higher (p < 0.05). Similar with acrosome damage and abnormalities, mitochondrial activity was slightly enhanced and the population of live sperm with high ROS level was decreased by 90% Percoll separation, however, there was no significant difference. Supplementation of 3 ng/mL ALA into Percoll solution increased sperm viability and decreased population of live sperm with high ROS compared to control (p < 0.05). In conclusion, discontinuous Percoll gradient before freezing process could improve efficiency of cryopreservation of boar sperm through selection of sperm with high freezing resistance, and supplement of ALA during Percoll gradient might contribute suppression of ROS generation via stabilizing of plasma membrane during cryopreservation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.2
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• pp.175-180
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• 2009

In this article, we fabricated polytetrafluoroethylene(PTFE) nozzle treated by ion beam, in order to fabricate polymer based electrospray micro thruster with super hydrophobic nozzle. To obtain the super hydrophobic surface, PTFE surface is treated by argon and oxygen plasma treatment process. The optimal condition is investigated argon and oxygen flow rate as well as the paalied energy level for the treatment process. Fabricated nozzle was evaluated by measuring contact angle, and the surface morphology was examined by using scanning electron microscope(SEM) and atomic force microscope(AFM). We observe that jetting becomes more stable and repeatable on the treated nozzle. And to evaluate performance of fabricated nozzle, we measure micro scale thrust using a cantilever and a nozzle treated by ion beam laser displacement sensor.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.447-447
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• 2010

일찍이 $SiO_2$ (Silicon dioxide) 박막은 다양한 분야에서 유전층, 부식 방지층, passivation층 등의 역할을 해왔다. 그리고 이러한 박막 공정은 대부분 진공의 환경에서 그 공정이 이루어지고 있다. 하지만 이러한 진공 system은 chamber, loadlock 그리고 펌프 등의 다양한 진공장비로 인한 생산 비용 증가, 공정의 복잡성뿐만 아니라 공정의 대면적화에 어려움을 지니고 있다. 그리고 최근 flexible display의 제조 공정에서 polymer 혹은 plastic 기판을 제조 공정에 적용시키기 위해 저온 공정이 필수적으로 요구 되고 있다. 이러한 기술적 한계를 뛰어 넘기 위해 최근 많은 연구가들은 atmospheric pressure plasma enhanced chemical vapor deposition (AP-PECVD)에 대해 지속적으로 다양한 연구를 하고 있다. 본 연구에서는 remote-type의 modified pin-to-plate dielectric barrier discharge (DBD) 시스템을 이용한 $SiO_2$ 무기 박막 증착에 관해 연구하였다. $O_2$/He/Ar의 gas와 5 kV AC power (30 kHz)의 전원장치를 통해 고밀도 대기압 플라즈마를 발생시켰고, silicon precursor로는 hexamethyldisilazane (HMSD)를 사용하였다. 먼저 HMDS와 $O_2$ gas의 flow rate 변화에 따른 증착률을 조사하였고 그 다음으로 박막의 조성 및 표면 특성을 조사하였다. HMDS의 유량이 100 ~ 300 sccm으로 증가함에 따라 증착속도는 증가했다. 하지만 FT-IR을 통해 HMDS의 유량이 증가하면 반응에 참여할 산소 분자의 부족으로 인해 $-(CH_3)_X$의 peak intensity가 증가하고, -OH의 peak intensity가 점차 감소함을 관찰 할 수 있었다. 또한 증착된 박막의 표면에 particle과 불균일한 surface morphology 등을 SEM image를 통해 관찰 하였다. 산소 유량이 탄소와 관련된 많은 불순물들의 제거에 도움이 됨에도 불구하고 14 slm 이상의 산소가 반응기 내로 주입되게 되면 대기압 플라즈마의 discharge가 불안정하게 되어 공정효율을 저하시키는 요소가 되었다. 결과적으로 HMDS (150 sccm)/$O_2$ (14 slm)/He (5 slm)/Ar (3 slm)의 조건에서 약 42.7 nm/min 증착률을 가지며, 불순물이 적고 surface morphology가 깨끗한 $SiO_2$ 박막을 증착할 수 있었다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.177-177
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• 2010

고효율 비정질 실리콘 박막 태양전지 제작을 위해서는 광파장대에서 optical confinement 능력을 최대화할 수 있는 기술이 필수적이다. 효율적인 photon trapping을 위해서는 back reflector를 사용하거나 전면전극인 투명전도성막의 표면에 요철을 형성하여 포획된 태양광의 내부 반사를 증가시키거나 전면 투명전극에서 반사를 감소시켜 태양광의 travel length를 증가시키는 방법이 일반적이며, 이를 통해 흡수층의 효율을 최대화할 수 있다. 이 중 전면전극으로 사용되는 투명전도성막은 불소가 도핑된 tin-oxide가 주로 사용되었으나, 최근 들어 Al이 도핑된 산화아연막을 이용한 비정질 실리콘 박막 태양전지 개발에 대한 연구도 활발히 진행되고 있다. 투명전극 증착후 표면의 유효면적을 증가시키기 위해 염산 용액을 이용하여 표면 텍스쳐링을 수행한다. 그후 흡수층인 p-i-n 층을 플라즈마 화학기상증착법을 이용하여 형성하는 것이 일반적이다. 이때 표면처리 된 투명전극은 수소플라즈마에 대해 특성이 변하지 않아야 고효율 비정질 실리콘 박막 태양전지 제조에 적용될 수 있다. 본 연구에서는 표면처리 된 AZO 투명전극의 수소플라즈마에 의한 특성 변화에 대해 고찰하였다. 먼저 AZO 투명전극은 스퍼터링 공정을 적용하여 $1\;{\mu}m$두께로 증착하였고, 0.5 wt%의 HCl 용액을 이용하여 습식 식각을 수행하였다. 수소플라즈마 처리 조건은 $H_2$ flow rate 30 sccm, working pressure 20 mtorr, RF power 300 W, Temp $60^{\circ}C$ 이며 3분간 진행하였다. 표면형상은 수소플라즈마 전 후에는 큰 차이를 보이지 않았으며 AZO의 grain size는 각각 220 nm, 210 nm로 관찰되었다. 투명전극의 가장 중요한 특성인 가시광선 영역에서의 투과도는 수소플라즈마 처리전에는 90 % 이상의 투과도를 보였으나, 수소플라즈마 처리 후에는 85 %로 약간 저하된 특성을 보였다. 그러나 이는 박막 태양전지용 전면전극으로 사용하기 위한 투과도인 80 % 이상을 만족하는 결과로, 비정질 박막 실리콘 태양전지 제작에 사용될 수 있다. 또 하나의 중요한 특성인 Haze factor 역시 수소플라즈마 처리 전 후 모두 10 이상의 값을 나타냈다. 하지만 고효율 실리콘 박막 태양전지에 적용하기 위해서는 Haze factor를 증가시키는 공정 개발에 대한 추가 연구가 필요하다.

• Biomolecules & Therapeutics
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• v.2 no.4
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• pp.336-342
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• 1994

The general pharmacological properties of EPO were investigated in various animals administering intravenously and in vitro system. The results were as follows. 1. Central nervous system: EPO at doses of 70, 700, 7000 U/kg showed no effect In mice on general behavior, on strychnine- and pentetrazol-induced convulsion and on acetic acid-induced writhing syndrome. The hexobarbital-induced sleeping time in mice was slightly reduced by EPO at a dose of 7000 U/kg but did not change at doses of 70, 700 U/kg. The body temperature in rats was slightly decreased by EPO at doses of 700, 7,000 U/kg but the change was in normal physiological range. 2. Respiratory and cardiovascular system: EPO showed no effect on respiratory rate, blood pressure, heart rate, femoral blood flow, and electrocardiogram in anesthetized dogs at doses of 70, 700, 7000 U/kg. 3. Smooth muscle: EPO at concentrations of 70, 700 U/ml had no effect on the contractile response of isolated guinea pig ileum to histamine and acetylcholine. 4. Water and electrolytes excretion: EPO at dose above 700 U/kg increased urine volume in rats but did not affect the concentrations of $Na^{+},\;K^{+},\;Cl^{-}$ in urine. 5. Gastrointestinal system: EPO(70, 700, 7000 U/kg) had no effect on the intestinal charcoal meal propulsion 6. Blood coagulation system: The administration of EPO(70, 700, 7000 U/kg) had no effect on the plasma prothrombin time(PT) and activated partial thromboplastin time(APTT) in mice. Platelet aggregation induced by ADP and collagen was not influenced by EPO(70 U/ml, 700 U/ml). The overall results obtained indicated that EPO exerts almost no serious pharmacological effect even at a 100-fold clinical dose(7000 U/kg).

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.2
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• pp.233-240
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• 2019

Objective: This study was to investigate the effects of dietary cotton stalk on nitrogen and free gossypol in sheep. Methods: Treatments included 25% cotton stalk (Treat 1), 50% cotton stalk (Treat 2), and a control (no cotton stalk). Six Xinjiang daolang wethers were cannulated at the rumen and duodenum and fed one of these diets. The effects of these diets on nitrogen and free gossypol absorption and metabolism were determined. Fifteen healthy Xinjiang daolang wethers were assessed for daily gain, tissue lesions, and free gossypol accumulation. Results: Dry matter intake decreased with increasing dietary cotton stalk. Total tract dry matter digestibility did not significantly differ among treatments. Dietary cotton stalk significantly decreased volatile fatty acids and increased ammonium nitrogen in the rumen. Nitrogen intake was significantly higher in Treat 2 than in the control or Treat 1. Nitrogen retention and free gossypol intake increased with dietary cotton stalk. Duodenal free gossypol flow did not increase, and free gossypol almost disappeared from the rumen. The free gossypol content of plasma and tissue was increased with dietary cotton stalk with liver free gossypol>muscle free gossypol>kidney free gossypol. Elevated dietary free gossypol decreased platelets, hemoglobin, and serum iron. Aspartate aminotransferase and ${\gamma}$-glutamyltransferase increased in Treat 2. With high long-term dietary cotton stalk intake, liver cells were swollen, and their nuclei dissolved. Renal cells were necrotic and the interstitia were enlarged. Conclusion: With short-term cotton stalk administration, only a small amount of free gossypol is retained in the body. In response to long-term or high free gossypol cotton stalk feeding, however, free gossypol accumulates in, and damages the liver and kidneys.

• Journal of Ginseng Research
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• v.43 no.4
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• pp.618-624
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• 2019

Background: Ginsenoside Re (Re) is one of the major components of Panax ginseng Meyer. Ginsenoside $Rk_3$ ($Rk_3$) is a secondary metabolite of Re. The aim of this study was to investigate and compare the effects and underlying mechanisms of Re and $Rk_3$ on cyclophosphamide-induced myelosuppression. Methods: The mice myelosuppression model was established by intraperitoneal (i.p.) injection of cyclophosphamide. Peripheral blood cells, bone marrow nucleated cells, and colony yield of hematopoietic progenitor cells in vitro were counted. The levels of erythropoietin, thrombopoietin, and granulocyte macrophage colony-stimulating factor in plasma were measured by enzyme-linked immunosorbent assay. Bone marrow cell cycle was performed by flow cytometry. The expression of apoptotic protein bcl-2, bax, and caspase-3 was detected by Western blotting. Results: Both Re and $Rk_3$ could improve peripheral blood cells, bone marrow nucleated cell counts, thymus index, and spleen index. Furthermore, they could enhance the yield of colonies cultured in vitro and make the levels of granulocyte macrophage colony-stimulating factor, erythropoietin, and thrombopoietin normal, reduce the ratio of $G_0/G_1$ phase cells, and increase the proliferation index. Finally, Re and $Rk_3$ could upregulate the expression of bcl-2, whereas they could downregulate the expression of bax and caspase-3. Conclusion: Re and $Rk_3$ could improve the hematopoietic function of myelosuppressed mice. The effect of $Rk_3$ was superior to that of Re at any dose. Regulating the levels of cytokines, promoting cells enter the normal cell cycle, regulating the balance of bcl-2/bax, and inhibiting the expression of caspase-3 may be the effects of Re and $Rk_3$ on myelosuppression.