폴리카보네이트 멤브레인 표면의 불소화 개질에 의한 물 투과도 변화

민광준,설용건,전명석,김홍곤 한국화학공학회 2003 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.41 No.6

균일한 기공을 가진 polycarbonate track etched membrane의 불소화로 인한 표면특성과 물 투과도의 변화를 조사하였다. 반응온도와 반응시간을 각각 상온과 3분으로 일정하게 유지하면서 질소로 희석된 혼합가스의 불소 농도 및 압력을 변화시켜 멤브레인을 불소화하였다. Field emission scanning electron microscopy(FESEM)을 통해 혼합가스의 절대압력이 1.5 bar 이하이고 불소, 질소 혼합비가 1:30으로 희석되었을 때 멤브레인 표면이 손상되지 않음을 알 수 있었다. 또한, 혼합비 1:30의 혼합가스로 1.5 bar에서 불소화한 멤브레인의 물 투과도는 원래 멤브레인의 2배 가까이 증가하였다. 불소화 압력이 낮으면 표면은 친수성을 띈 반면, 불소화 압력이 증가하면 소수성으로 변하였다. X-ray photoelectron spectroscopy(XPS)를 통해 불소 분압이 높아짐에 따라 멤브레인 표면에서 내부로의 불소 침투속도가 증가하는 현상과 불소가 도입된 부분의 산소 함량이 증가한 현상을 볼 수 있었다. 표면이 소수성을 띄는 멤브레인의 물 투과도가 증가한 현상은 기공 표면이 소수성을 띌수록 slip 경계조건에 근접하게 되어 기공을 통한 물 흐름이 원활해졌기 때문으로 해석되었다. The effect of fluorination on the surface characteristics and water permeability of an isopore polycarbonate track etchet membrane was examined. The membrane was fluorinated with gas mixtures containing fluorine and nitrogen of various composition under various pressure at room temperature for 3 minutes. The field emission scanning electron microscopy(FESEM) analysis showed that the shape of the membrane surface was not changed when it was fluorinated with a gas mixture at 1.5 bar which contained a low molar ratio of fluorine to nitrogen such as 1:30. Meanwhile, the membrane fluorinated with a mixture having a F₂:N₂ ratio of 1:30 at 1.5 bar showed an improved water permeability almost twice higher than that the original membrane had. The membrane surface got to possess more hydrophilicity than the original one when it was mildly fluorinated at low pressure. However, it became hydrophobic when it was further fluorinated under higher pressure. X-ray photoelectronospectroscopy(XPS) analysis revealed that the penetration rate of fluorine into the membrane increased along with the increase of the partial pressure of fluorine and that the inner layer containing fluorine possessed more oxygen than that in the original membrane. The phenomenon that the membrane having hydrophobic surface showed high water permeability was due to the slip boundary condition in the pore surface where water droplets pass through hydrophobic pores more easily with less friction resistance than through hydrophilic pores.

내연 기관의 연소실 압력 측정을 위한 자료 취득 장치의 개발

전광민,최세진,장원준 연세대학교 산업기술연구소 1990 논문집 Vol.22 No.2

This paper describes the development procedure of the data acquistion system that is user oriented. This high-speed data acquistion system can measure the normal cylinder pressure and the pressure wave caused by the knock occurence. YEDAS, the developed data acquisition system for the cylinder pressure measurement, can take about 200 cycles of the engine cylinder pressures continuously at 3000rpm. Also, YEDAS can take 16 channels of temperature measurement and can control the throttle plate. The maximum speed of the data acqusition is up to 150kHz.

단일 영역 열방출량 계산법을 이용한 스파크 점화 기관의 압력해석

전광민,명노완 연세대학교 산업기술연구소 1990 논문집 Vol.22 No.2

One-zone heat release analysis was studied theoretically and experimentally. A single cylinder spark-ignition engine was used for experiment. 20 cycles of cylinder pressure were taken at 2000 RPM, wide open throttle condition. The calculated amount of heat release at the end of combustion process matched well with the measured fuel energy which is the mass of fuel multiplied by lower heating value.

Conditioned Media of ASC-17D Sertoli Cells Induce G1-Growth Arrest of DU145 Human Prostate Cancer Cells

Min, Bon Hong,Kang, Sang Wook,Lee, Kwang Ho,Choi, Sang Hyun,Kang, Hyeog,Chun, Boe Gwun The Korea Science and Technology Center 1998 BMB Reports Vol.31 No.5

We studied the effects of ASC-17D rat Sertoli cell-conditioned media (rSCCM) on the proliferation of the DU145 prostate cancer cells. rSCCM was prepared from ASC-17D cells cultured in DMEM/F-12 serum-free media at a nonpermissive temperature of 40℃, which is the condition for the high expression of clusterin. We found that rSCCM could inhibit the proliferation of DU145 cells by arresting the cell cycle in the G1 phase in a dose-dependent manner. This growth arresting activity was abolished by boiling rSCCM for 5 min. The G1 growth-inhibiting activity of rSCCM was also detected in other prostate-originated cancer cells examined (ie., LNCaP and PC-3) but not in other cells (ASC-17D, HepG2, SK-N-SH, and NIH3T3). Western blot analysis of partially purified growth inhibiting fractions with the clusterin antibody showed that the cytostatic factor in rSCCM was not clusterin. This cytostatic factor was semipurified by DEAE-Sepharose, ammonium sulfate precipitation, and Phenyl-Sepharose column chromatography, and was estimated to have a molecular weight of 88 kDa by Sephacryl S-300 gel filtration.

Conditioned Media of ASC-17D Sertoli Cells Induce G1 - Growth Arrest of DU145 Human Prostate Cancer Cells

Lee, Kwang Ho,Kang, Hyeog,MIN, BON HONG,Kang, Sang Wook,Choi, Sang Hyun,Chun, Boe Gwun 생화학분자생물학회 1999 BMB Reports Vol.31 No.5

We studied the effects of ASC-17D rat Sertoli cell-conditioned media (rSCCM) on the proliferation of the DU145 prostate cancer cells. rSCCM was prepared from ASC-17D cells cultured in DMEM/F-12 serumfree media at a nonpermissive temperature of 40℃,which is the condition for the high expression of clusterin. We found that rSCCM could inhibit the proliferation of DU145 cells by arresting the cell cycle in the G1 phase in a dose-dependent manner. This growth arresting activity was abolished by boiling rSCCM for 5 min. The G1 growth-inhibiting activity of rSCCM was also detected in other prostate-originated cancer cells examined (i.e., LNCaP and PC-3) but not in other cells (ASC-17D, HepG2, SK-N-SH, and NIH3T3). Western blot analysis of partially purified growth inhibiting fractions with the clusterin antibody showed that the cytostatic factor in rSCCM was not clusterin. This cytostatic factor was semipurified by DEAE-Sepharose, ammonium sulfate precipitation, and Phenyl-Sepharose column chromatography, and was estimated to have a molecular weight of 88 kDa by Sephacryl S-300 gel filtration.

토끼에서 근육주사시 입자 크기에 따른 amoxicillin의 비교 약물동태학

박승춘,윤효인,오태광,장범수,배순이,조준형,정상희,이내경,김민규 충남대학교 수의과대학 동물의과학연구소 1998 動物醫科學硏究誌 Vol.6 No.-

To investigate the pharmacokinetic difference between the two amoxicillin (AMX) particles in rabbits after intramuscular injection (i.m.), both of AMX-S (particle size: 10 ㎍) and AMX-L (particle size: 100 ㎍) were injected into New Zealand White rabbits (1.2±0.3 ㎏) at a dose rate of 10 ㎎/㎏ of body weight. In this study, serum AMX concentrations were detected by microbiological assay with E. coli BE 1186 which shows high antibiotic sensitivity. After i.m. administration, AMX-S and AMX-L were best fitted as 1-compartment model with the absorption and elimination phase. The biological half-life (T_1/2, _k10) of AMX-S is 4.06±1.09 h and that of AMX-L 4.76±0.69 h. The serum maximal concentration time (T_max) of AMX-S and AMX-L were 0.88±0.17 h and 0.77±0.11 h, respectively. Maximal AMX concentration (C_max) (AMX-S: 5.71±0.62 ㎍/㎖, AMX-L: 5.04±0.25 ㎍/㎖) in serum showed a significant difference (p<0.05). In terms of bioequivalance, however, there was no difference between the two AMX's after i.m. injection in the basis of C_max and AUC.

점화 연소기관의 엔진 시뮬레이션 코드의 개발 : Concerning The Intake Flow 흡기관 유동에 관하여

곽기웅,전광민 연세대학교 산업기술연구소 1990 논문집 Vol.22 No.2

The intake process of a single cylinder spark-ignition engine was studied numerically and experimentally. Method of characteristics was used to calculate the pressure wave phenomena in the intake system. The calculated volumetric efficecy as a function of engine speed was compared with the experimentally measured value. The comparison showed good agreement at low engine speed but some discrepancy at high speed.

토끼에서 enrofloxacin과 enrofloxacin acetate의 比較藥物動態學

윤효인,박승춘,김창식,김민규,최기섭,신광순,박종일,조준형,조명행 충남대학교 수의과대학 동물의과학연구소 1996 動物醫科學硏究誌 Vol.4 No.-

This study was designed to examine the in vitro antibacterial activities and pharmacokinetics of enrofloxacin acetate (ENFXA) and enrofloxacin (ENFX). Two enrofloxacins had wide spectrum antibacterial activities against Gram positive and negative bacteria, and mycoplasma, showing potent antibacterial activities with low MICs (0.05-3.33 ㎍/㎖ for Gram positives, 0.002 ㎍/㎖ for Gram negatives and 0.02 ㎍/㎖ for mycoplasma). In order to investigate the profiles of two formulations of enrofloxacin we studied comparative pharmacokinetics of them in rabbits. Five rabbits were given 5 ㎎/㎏ body weight of each enrofloxacin formulation intravenously (i.v.) and orally (p.o.) in a cross-over study. Pharmacokinetic parameters of both formulations were calculated by the use of PCNONLIN, a computer program. Their bioavailibility in rabbits, the means of the area under the curve (AUC). After oral administration of each formulation in rabbits, the mean elimination half-lives (t_1/2,ke) were 3.25h (ENFX) and 4.32 h (ENFXA), and mean AUC 4.27 ㎍·h/㎖ (ENFX) and 6.21 ㎍·h/㎖ (ENFXA). Both enrofloxacin formulations seemed to have good tissue distribution and penetration as indicated by large volume of distribution: 4.76 1/㎏ for ENFX and 7.23 1/㎏ for ENFXA. With the results obtained in this study, ENFXA could be used in place of ENFX in rabbits.

AISI1045 기계구조용 탄소강의 질화 가스분위기에 따른 화합물층의 형성 및 조직변화

이원범 ( Won-beom Lee ),유광춘 ( Kwang-chun Yu ),김영민 ( Young-min Kim ),위재용 ( Jae-lyoung Wi ) 대한금속재료학회(구 대한금속학회) 2016 대한금속·재료학회지 Vol.54 No.7

Compound layers developed at 520 ℃ during gaseous nitriding of AISI 1045 steels were investigated. The nitriding potential (Kn) of a gas atmosphere of dissociating ammonia gas was checked by observation of the partial pressure of hydrogen gas. The microstructural evolution of the compound layer was studied by using optical microscopy and scanning electron microscopy. It was observed that the surface hardness was about 600 Hv after the nitriding treatment and the case depth was about 0.5mm after a nitriding treatment of 1440 min. The compound layer was composed of  ′(Fe4N) and ε(Fe2-3N). The thickness of the compound layer was simultaneously increased to 16 μm during the nitriding treatment of 1440 min. The kinetics of the compound layer growth were discussed with a modified Lehrer diagram of AISI 1045 steels, which was obtained from the thermodynamic calculation. †(Received January 15, 2016; Accepted March 2, 2016)

Conditioned Media of ASC-17D Sertoli Cells Induce G1-Growth Arrest of DU145 Human Prostate Cancer Cells

Kang, Hyeog,Kang, Sang-Wook,Choi, Sang-Hyun,Lee, Kwang-Ho,Chun, Boe-Gwun,Min, Bon-Hong Korean Society for Biochemistry and Molecular Biol 1998 Journal of biochemistry and molecular biology Vol.31 No.5

We studied the effects of ASC-17D rat Sertoli cell-conditioned media (rSCCM) on the proliferation of the DU145 prostate cancer cells. rSCCM was prepared from ASC-17D cells cultured in DMEM/F-12 serum-free media at a nonpermissive temperature of $40^{\circ}C$, which is the condition for the high expression of c1usterin. We found that rSCCM could inhibit the proliferation of DU145 cells by arresting the cell cycle in the G1 phase in a dose-dependent manner. This growth arresting activity was abolished by boiling rSCCM for 5 min. The G1 growth-inhibiting activity of rSCCM was also detected in other prostate-originated cancer cells examined (i.e., LNCaP and PC-3) but not in other cells (ASC-17D, HepG2, SK-N-SH, and NIH3T3). Western blot analysis of partially purified growth inhibiting fractions with the clusterin antibody showed that the cytostatic factor in rSCCM was not c1usterin. This cytostatic factor was semi purified by DEAE-Sepharose, ammonium sulfate precipitation, and Phenyl-Sepharose column chromatography, and was estimated to have a molecular weight of 88 kDa by Sephacryl S-300 gel filtration.