노즐 형상에 따른 전기수력학 프린팅의 실험적 연구

김지영(Ji Young Kim),부닷귀엔(Vu Dat Nguyen),변도영(Do Young Byun) 한국가시화정보학회 2011 한국가시화정보학회지 Vol.9 No.2

The shape of nozzle cross-section plays an important role in stabilizing electrospray jet. The angle of contact line is governed based on the famous Young-Laplace equation. Compared to a round nozzle that has a constant curvature along the orifice, the square nozzle has four square corner edges and four straight edges that hold the meniscus in a different manner and is of interest in this study. By utilizing both square and round capillary nozzle, we examine the effect of nozzle shape in electrohydrodynamic jetting. The ejections were recorded with a high speed camera and analyzed to examine the jetting repeatability based on dynamic movement of meniscus. The result suggests that if the corner edges are not sharp, then its effect on repeatability is also limited.

갑상선 종양에서 thrombin receptor (PAR-1)의 발현 양상

박지영,목지오,김여주,박형규,김철희,변동원,서교일,유명희,조현득,오미혜,김상진 순천향의학연구소 2006 Journal of Soonchunhyang Medical Science Vol.12 No.2

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광범위 외측 접근법으로 수술한 종골 골절의 술 후 조기 합병증

변영수,조영호,박준우,이진석,김지환 대한골절학회 2004 대한골절학회지 Vol.17 No.4

목적 : 광범위 외측 접근법으로 수술한 종골 골절에서 술 후 조기 합병증들을 분석하고 창상 합병증에 대한 위험 요인들을 알아보았다. 대상 및 방법 : 1990년 7월부터 2003년 2월까지 광범위 외측 접근법으로 수술한 종골 골절 104명, 116예를 대상으로 하였다. 환자들의 병록지에서 술 후 조기에 발생한 합병증들을 조사하여 분석하였으며, 창상 합병증의 위험을 증가시키는 요인들을 알아보기 위해 예견되는 변수들에 대하여 통계학적 분석을 하였다. 결과 : 감염이 14예 (12.0%)에서 발생하였으며, 10예 (8.6%)는 표재 감염이었고 4예 (3.4%)는 삼부 감염으로 수술적 치료가 필요하였다. 피부 괴사가 8예 (6.9%)에서 발생하였으며, 6예 (5.2%)는 수술창 변역부의 피부 괴사였고 2예 (1.7%)는 피판 괴사로 수술적 치료가 필요하였다. 비복신경 손상이 7예 (6.0%)에서 발생하였으나 부가적인 치료 없이 회복되었다. 통계학적 분석 결과 개방성 골절 군(p=0.003)과 수술시간이 90분 이상 연장된 군 (p=0.049)에서 창상 합병증의 발생률이 유의하게 높았다. 결론 : 광범위 외측 접근법으로 수술한 종골 골절에서 술 후 조기 합병증의 발생률이 높으므로 개방성 골절에서는 개방창을 철저하게 치료하고, 술 전 계획과 계획된 술기를 통하여 수술 시간을 90분 이내로 단축하고, 비복신경의 해부학적 위치를 고려하여 절개함으로 술 후 조기 합병증의 발생률을 감소시킬 수 있을 것으로 사료된다. Purpose : To analyze early postoperative complications of calcaneal fractures operated by a lateral extensile approach and to identify risk factors for would complications. Materials and Methods : From July 1990 to February 2003, 116 calcaneal fractures in 104 patients were treated by open reduction and internal fixation through a lateral extensile approach. The patient's records were reviewed for early postoperative complications. Statistical analysis was performed to determine significant relationships between predicted variables and the development of would complications. Results: Fourteen fractures (12.0%) developed infection. Ten of them were superficial infection and four were deep infection that required surgical treatment. Eight fractures (6.9%) developed skin necrosis. Six of them were marginal skin necrosis and two were flap necrosis that required surgical treatment. Seven fractures (6.0%) developed sural nerve injury, but their symptoms were improved without additional treatment. Open fracture (p=0.003) and prolonged operating time (p=0.049) increased significantly the rate of wound complications. Conclusion: The rate of early postoperative complications of calcaneal fractures operated by a lateral extensile approach is high. These complications can be reduced by meticulous treatment of an open wound, reduced operating time within 90minutes through preoperative planning and skillful technique, and correct incision to avoid damage of the sural nerve.

人蔘이 卵巢摘出로 誘發된 흰쥐의 骨多孔症 예방에 미치는 효능

정국영,서부일,이은숙,변부형,신순식,박지하 대한본초학회 2004 大韓本草學會誌 Vol.19 No.1

Objectives : The present study has been undertaken to investigate the effects of Ginseng Radix on prevention of osteoporosis in ovariectomized rats. Methods : In this experiment, the rats were ovariectomized. Rats were administered by 2 kinds of medicine, Estradiol, Ginseng Radix. The levels of bone mineral density, osteocalcin, ALP, phosphorus, calcium in serum, deoxypyridinoline in urine, calcium, phosphorus, ash weight of bone, body weight and uterus weight were measured. Results : The levels of spinal bone mineral density was significantly increased in comparison with OVX group at 8 weeks in Ginseng Radix group. The levels of serum didn t show significant change in comparison with OVX group in Ginseng Radix group. The levels of urine deoxypyridinoline showed significant decrease in comparison with OVX group in Ginseng Radix group. The levels of femoral and fibula-tibial ash weight didn t show significant increase in comparison with OVX group in Ginseng Radix group. The levels of femoral and fibula-tibial calcium showed significant increase in comparison with OVX group in Ginseng Radix group. The levels of femoral and fibula-tibial phosphorus showed significant increase in comparison with OVX group in Ginseng Radix group. The levels of body weight didn t show significant changes in comparison with OVX group in Ginseng Radix group. The levels of uterus weight didn t show significant changes in comparison with OVX group in Ginseng Radix group. Conclusions : Reviewing these experimetal results, it appears that Ginseng Radix have efficacy on prevention of osteoporosis. And further study should be conducted to illustrate in depth the curing and prevention of osteoprosis.

수종 한약재가 백혈병 세포에 미치는 영향에 대한 연구

崔湖榮,金澤,柳志昌,卞德市,盧昇鉉 대한본초학회 1999 大韓本草學會誌 Vol.14 No.1

I am reporting here a syntematic in vitro examination for specificity of anti-cancer effect of several oriental herbs, which have been used frequently for cancer pateints(therapy), on Molt-4 LCL(Lymphoblastoid Cell Line) Leukemic cells in relation to its density and time of incubation. 1. ErOH extract of Jujubae Fructus reduced Molt-4 cell's survival rate effectively after 48 hours' treatment at 1000㎍/㎖'s density and it reduced survival rate of LCL effectively after 12 hours' treatment at 1000㎍/㎖'s density. 2. EtOH extract of Cordyceps reduced LCL's survival rate effectively after 36 hour's treatment at 1000㎍/㎖'s density. 2. EtOH extract of Fici Fructus reduced LCL's survival rate effectively after 36 hours' treatment at 1000㎍/㎖'s density. 4. EtOH extract of Trionycis reduced Molt-4 cell's survival rate even at 500㎍/㎖ density and further effective at 1000㎍/㎖ density after 24 hours treatment and it killed the cells completely at 1000㎍/㎖ density after 48 hours treatment, It also Killed LCL completely after 12 hours and 36 hours' treatment at 1000㎍/㎖'s density. 5. EtOH extract of Biotae Cacumen reduced LCL's survival rate effectively after 12 hours' treatment at 1000㎍/㎖'s density, and after 36 hours treatment it reduced LCL's survival time very effectively. 6. EtOH extract of Psoraleae Fructus reduced Molt-4 cell's survival rate very effectively after 24 hours' treatment at 500㎍/㎖ and 1000㎍/㎖'s density, and after 48 hours' treatment at 250㎍/㎖'s density it reduced effectively and it killed the cell completely at 500㎍/㎖ and 1000㎍/㎖'s density. It also killed LCL completely after 12 hours and 36 hours' treatment at 1000㎍/㎖'s density. I hope to proceed with more advanced experiment in vivo and clinically as for the two kinds of oriental herbs and another herbs effective for leukemia.

umu-test에 의한 2-bromopropane의 遺傳毒性 調査

金永煥,池用熙,邊子眞,金範錫,柳寅晟 高麗大學校 倂設 保健大學 保健科學硏究所 1996 保健科學論集 Vol.22 No.1

Genotoxicity/mutagenicity of 2-bromopropane and toluene, benzene, trichloroethylene was investigated using umu-test with a Salmonella typhimurium TA1535 strain. The tester strain was derived by introducing plasmid pSK 1002, which carried a umu C-lac Z fussion gene into S.typhimurium TA1535, and tester strain in the presence of microsomal activation proved to be the more sensitive maker of genotoxcicity. Among the chemicals examined 4 compound induced umu gene expression, which could be defined on a basis of increased β-galactosidase activity in all 2- fold over the background level. But β-galactosidase activity appearance in all experiment chemical was not so high in compared with that background level.

Poly(ρ-phenylenesulfide)와 Poly(ρ-phenylene)으로부터 제조된 탄소의 리튬 이온 2차전지 anode 재료로서의 전기화학적 특성

유덕영,이주성,박수길,변지형,류신환,정윤이 한양대학교 에너지·환경기술연구소 1998 에너지·環境技術論文集 Vol.4 No.-

Poly(p-phenylenesulfide)와 poly(p-phenylene)으로부터 제조된 탄소를 리튬이온 2차전지용 음극재료로 사용하여 전기화학적특성을 연구하였다. 이들 고분자들을 질소 분위기하에서 승온속도 2℃/min로 1000℃까지 상승시킨 후, 1시간 동안 탄화시켜 탄소를 제조하였다. Poly(p-phenylene)으로부터 제조된 탄소가 보다 더 규칙적인 구조를 가지기 때문에 Poly(p-phenylenesulfide)으로부터 제조된 탄소보다 더 많은 용량과 충방전 효율을 나타내었다. 수산화리튬과 염화주석(Ⅱ)을 첨가하여 용량의 증가와 충방전 효율의 증가를 가져올 수 있었다. 이중에서 poly(p-phenylene)에 염화주석(Ⅱ)을 첨가시켜 제조된 탄소가 가장 큰 충방전 용량과 충방전 효율의 향상을 가져왔다. Carbon inaterials manufactured from poly(p-phenylene sulfide) and poly(p-phenylene), were studied on electrochemical characteristics as anode materials for lithium ion secondary battery. These polymer precursors were heat treated for 1hr at 1000℃ with the rate 2℃/min under nitrogen atmosphere. Carbon manufactured from poly(p-phenylene) showed higher capacity and coulomb efficiency of charge/discharge than carbon from poly(p-phenylene sulfide) because the former has better ordered structure. Carbon manufactured from polymer precursors adding stannous chloride or lithium hydroxide showed higher capacity and better efficiency of charge/discharge. Also, carbon manufactured by adding stannous chloride to poly(p-phenylene) showed the highest capacity and efficiency of charge/discharge.

DC Arc로의 유동/열전달 해석 - 용강영역(2)

정순효,변지영,오영주 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.8

Heat- and fluid-flow phenomena in the molten steel region in a DC arc furnace were investigated by simultaneous analysis of electromagnetic, flow and temperature fields. It was found that the flow pattern in molten steel was determined by electromagnetic and buoyancy forces rather than the shear force at the melt surface due to the high velocity plasma arc. While the short arc with high current made the hot region beneath the arc expanded, the long arc with high current drove the melt temperature high. And the low arc current led to the non-homogeneous temperature distribution of the melt because the bottom region of the melt was not stirred sufficiently.

Purs Lane의 유용성분과 아질산염 소거능 검색

김향숙,변복수,최주희,박지영 충북대학교 교육생활연구소 2001 생활과학연구논총 Vol.4 No.-

This study was carried out to examine the useful components of Purs Lane and their nitrite scavenging effect. Leaves and stems were separated and analyzed fo general chemical composition, amino acid composition, and dietary fiber contents. Anti-oxidant nutrient such as total vitamin C, total phenol ice, and vitamin E contents were also analyzed. Nitrite scavenging effects of methanol extract and aqeous extract were examined.

AZ91 합금융체내의 Fe 용해도

권순일,변지영,김선진,심재동 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.1

Fe solubility in AZ91 alloy melts was measured by a new method designed for removal of Al_(8)(Mn,Fe)_(5) inclusions. In the AZ91 alloy melts, Al_(8)(Mn,Fe)_(5) precipitates were formed due to supersaturated Mn and Fe, but all precipitates were not settled down from the melts and hence part of them was included in the samples for measuring Fe solubility. This means that the solubility measured from these samples is higher than the true solubility. In the present study, it was shown that these Al_(8)(Mn,Fe)_(5) inclusions could be separated from the samples by the new method. As a result, the Fe solubility measured by the present method was lower than the previous solubility data. Amount of the unsettled Al_(8)(Mn,Fe)_(5) inclusions was estimated to be 59-148 ppm. It was also observed that Fe contents in Al_(8)(Mn,Fe)_(5) were varied with the Fe and Mn content in AZ91 alloy melts.