Numerical Study on Bouncing and Separation Collision Between Two Droplets Considering the Collision-Induced Breakup

Ko, Gwon-Hyun,Ryou, Hong-Sun,Hur, Nahm-Keon,Ko, Seung-Woo,Youn, Myoung-O 대한기계학회 2007 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.21 No.4

The main purpose of the present study is to perform numerical study on bouncing and separation collision between two droplets considering the collision-induced breakup. In this study, the collision model proposed in our previous study is used for simulation of collision-induced breakup, and we modify this model to consider the effect of liquid property on the behavior of droplet-droplet collision. This collision model is based on the conservation laws for mass, momentum, and energy between before and after collision and provides several formulae for post-collision characteristics of colliding droplets and satellite droplets. Improving the accuracy of the model, in this study, appreciate criterion for bouncing collision is added and dissipation energy during collision process is newly modeled. To validate the new model, numerical calculations are performed and their results are compared with experimental data published earlier for binary collisions of water, propanol, and tetradecane droplets. It is found from the results that the new model shows good agreement with experimental data for the number of satellite droplets. It can be also shown that the predicted mean diameter by the new model decrease with increasing the Weber number because of the collision-induced breakup, whereas the O'Rourke model fails to predict the size reduction via the binary droplet collision.

일본잎갈나무 , 잣나무 , 신갈나무 임분 토양수 성질의 계절적 변이

오종민,진현오,손요환,주영특,정덕영,류성렬 한국환경농학회 2000 한국환경농학회지 Vol.19 No.1

토양수 내 이온 농도의 계절적 변이를 구명하기 위하여 경기도 광주군 퇴촌면에 위치한 26년생 일본잎갈나무, 잣나무, 신갈나무 임분의 O층, A층, B층에 zero tension lysimeter를 설치하고 1996년 9월부터 1999년 6월까지 토양수를 채취하여 분석하였다. 10월과 11월에 토양수 내 K^+, Mg^2+, Cl^-, NO_3^-등의 농도가 증가하였는데, 이는 가을철 낙엽 및 낙지의 유입에 의한 것으로 보이며, 3월과 4월에 Na^-, Ca^2+, K^+, Mg^2+ 등의 농도가 증가하는 것은 봄철에 빈번하게 발생하는 황사현상에 기인하는 것으로 사료된다. 또한 토양수 내 이온 가운데서 K^+의 농도가 연중 계절별로 가장 크게 변하는 것으로 나타났으며, 토양수 내 CI 농도는 K^+, Mg^2+ 농도와 양의 상관관계를 나타내었다. 단변량 시계열 분석 결과 연구기간 동안 토양수 pH는 지속적으로 감소하는 반면 Al^3+과 K^+농도는 증가하는 경향을 나타내었다. 이와 같은 경향이 지속될 경우 O층 토양수 내 Al^3+농도가 식물체에 피해를 줄 수 있는 최소농도 (0.018 meq/1)에 도달하려면 수종에 따라 차이는 있으나 10-20년이 소요될 것으로 추정되었다. To investigate seasonal variations of soil solution chemistry, samples were collected from zero tension lysimeters in O, A, and B horizons of 26-year-old Larix leptolepis. Pinus koraiensis and Quercus mongolica stands in Kwangju, Kyunggi Province from September, 1996 through June. 1999. Potassium, Mg^2+, Cl^-, and No_3^- concentrations increased in October and November concurrent with inputs of fresh litterfall and twigs. Sodium, Ca^2+, K^+, and Mg^2+ concentrations increased in March and April concurrent with the yellow sand effect. Potassium concentration showed the highest variation among ions, and Cl^- concentration showed positive correlations with K^+ and Mg^2+ concentrations. Soil solution pH decreased while Al^3+ and K^+ concentrations increased during the study period. If our data reflects long term trends. then Al^3+ concentration in the O horizon will reach the toxic level (0.180 meq/1) within 10-20 years depending on species

Medicinal Chemistry : RESEARCH ARTICLE ; Selective induction of hepatic cytochrome P450 2B activity by leelamine in vivo, as potent novel inducer

( Ju Hee Kim ),( Woong Sik Nam ),( Doo Hyun Lee ),( Su Youn Lee ),( Hung Chan O ),( Jeong Min Joo ),( Kwang Hyeon Liu ),( Jae Yun Han ),( Sung Hwan Ki ),( Tae Cheon Jeong ),( Tae Ho Lee ),( Sang Kyu L 영남대학교 약품개발연구소 2015 영남대학교 약품개발연구소 연구업적집 Vol.25 No.-

Cytochrome P450 (cyp) is an important enzyme that can act on xenobiotic substances such as toxic chemicals or drugs. Phenobarbital(PB) has been widely used to induce CYP2B activity to investigate the drug-drug interaction of CTP2B substrate drugs.leelamine is a diterpene compound, and is the current focus of efforts to develop a treatment for diabetes. In this study. we identi-fied the selective and potent inductive effct of leelamine on CYP2B antdoes of 5,10,or 20 mg/kg in male ICR micc for I or 3 days. In liver, the activity of CYP2B significantly increased 3.6-fold after treatment with leelamine,com-pared to vehicle-treated group. Activities of benzyloxy-resorufin O-dealkylase and pentoxyresorufin O-dealkylase significantly increased 6.3-and 5.3-fold, respectively,with a single treatment of 20 mg/kg leelamine for I day. Fur-thermore. immunoblot analysis showed that signifieantly and dose-dependently increased CYP2B10 protein levels in liver.However,PCR results showed that there were no significant changes in the CAR and CYP2B mRNA levels after leelamine treatment. Accordingly, we suggest that leelamine is a novel substitute of PB for the seleetive inudction of CYP2B activity in vivo.

Expression Patterns of HIF-1α Under Hypoxia in Vascular Smooth Muscle Cells of Venous Malformations

Chung, Ho Yun,Lee, Seok Jong,Lee, Jong Min,Huh, Seung,Kim, Hyung Kee,Kwon, O Hyun,Lim, Hyun Ju,Oh, Eun Jung,Kim, Tae Jung,O, Teresa M.,Waner, Milton Wolters Kluwer Health, Inc. All rights reserved. 2015 Annals of plastic surgery Vol.75 No.3

PURPOSE: The molecular pathophysiology of venous malformations (VMs), which are a type of vascular malformation, is poorly understood. Until now, it is known that VM lesions are related to the process of angiogenesis. Because angiogenesis is induced under hypoxic conditions, hypoxia is thought to be important in VM lesion formation. Therefore, we examined the implications of hypoxia on the biological behavior of VM vascular smooth muscle cells (VSMCs). In doing so, we investigated the expression patterns of hypoxia-inducible factor-1α (HIF-1α), which plays a key role in hypoxia-induced angiogenesis, to provide a further understanding of the molecular mechanisms involved in VM. METHODS: Vascular smooth muscle cells from 5 normal veins and 5 VM lesions were cultured under moderate hypoxic conditions (3% O2, 5% CO2). The effects of hypoxia on HIF-1α expression were measured by immunocytochemical staining, reverse transcription-polymerase chain reaction, and real-time reverse transcription-polymerase chain reaction. RESULTS: Overall, the expression of HIF-1α in cells was high after exposure to hypoxia for 6 or 12 hours, but decreased after 24 hours of hypoxia. HIF-1α expression in VM VSMCs was 2 times higher than that in normal VSMCs. Immunocytochemically, HIF-1α was mainly located in the nucleus and the intensity in VM VSMCs was stronger after 6 and 12 hours of hypoxia when compared to the expression pattern of HIF-1α in VSMCs from normal tissue. This suggested that VM tissue is more susceptible to the effects of hypoxia than normal tissue. CONCLUSIONS: These results indicate that the high expression of HIF-1α in VM VSMCs under hypoxic conditions could be an important factor for stimulating downstream angiogenesis in VM. Furthermore, the results of this investigation could provide the basis for future studies of VM pathophysiology, and ultimately lead to the development of new therapeutic approaches.

Subcellular Localization of the Barley Stripe Mosaic Virus Triple Gene Block Proteins

Lim, Hyoun-Sub,Bragg, Jennifer N.,Ganesan, Uma,Ruzin, Steven,Schichnes, Denise,Lee, Mi Yeon,Vaira, Anna Maria,Ryu, Ki Hyun,Hammond, John,Jackson, Andrew O. American Society for Microbiology 2009 Journal of virology Vol.83 No.18

<B>ABSTRACT</B><P><I>Barley stripe mosaic virus</I> (BSMV) spreads from cell to cell through the coordinated actions of three triple gene block (TGB) proteins (TGB1, TGB2, and TGB3) arranged in overlapping open reading frames (ORFs). Our previous studies (D. M. Lawrence and A. O. Jackson, J. Virol. 75:8712-8723, 2001; D. M. Lawrence and A. O. Jackson, Mol. Plant Pathol. 2:65-75, 2001) have shown that each of these proteins is required for cell-to-cell movement in monocot and dicot hosts. We recently found (H.-S. Lim, J. N. Bragg, U. Ganesan, D. M. Lawrence, J. Yu, M. Isogai, J. Hammond, and A. O. Jackson, J. Virol. 82:4991-5006, 2008) that TGB1 engages in homologous interactions leading to the formation of a ribonucleoprotein complex containing viral genomic and messenger RNAs, and we have also demonstrated that TGB3 functions in heterologous interactions with TGB1 and TGB2. We have now used <I>Agrobacterium tumefaciens</I>-mediated protein expression in <I>Nicotiana benthamiana</I> leaf cells and site-specific mutagenesis to determine how TGB protein interactions influence their subcellular localization and virus spread. Confocal microscopy revealed that the TGB3 protein localizes at the cell wall (CW) in close association with plasmodesmata and that the deletion or mutagenesis of a single amino acid at the immediate C terminus can affect CW targeting. TGB3 also directed the localization of TGB2 from the endoplasmic reticulum to the CW, and this targeting was shown to be dependent on interactions between the TGB2 and TGB3 proteins. The optimal localization of the TGB1 protein at the CW also required TGB2 and TGB3 interactions, but in this context, site-specific TGB1 helicase motif mutants varied in their localization patterns. The results suggest that the ability of TGB1 to engage in homologous binding interactions is not essential for targeting to the CW. However, the relative expression levels of TGB2 and TGB3 influenced the cytosolic and CW distributions of TGB1 and TGB2. Moreover, in both cases, localization at the CW was optimal at the 10:1 TGB2-to-TGB3 ratios occurring in virus infections, and mutations reducing CW localization had corresponding effects on BSMV movement phenotypes. These data support a model whereby TGB protein interactions function in the subcellular targeting of movement protein complexes and the ability of BSMV to move from cell to cell.</P>

원시적 지속성 삼차신경동맥 동맥류 : 증례보고 A Case Report

강현승,한대희,권오기,오창완,정희원,최길수 대한신경외과학회 1997 Journal of Korean neurosurgical society Vol.26 No.5

열산화된 알루미늄이 첨가된 Tin black filter를 가지는 메탄센서

권오식,황숙이,심창현,임채근,방영일,김봉철,허증수,류기홍,이덕동 경북대학교 센서기술연구소 2002 센서技術學術大會論文集 Vol.13 No.1

智異山 면양목장 조성에 관한 연구 : Ⅷ報. 智異山 山野草가 緬羊의 繁殖率에 미치는 영향과 羊毛의 加工利用方法, 販路方案, 貯藏法 및 緬羊團地造成時의 經濟性 分析 Ⅷ. Effect of the native herbages in Mt. Chiri on the breeding percentage of sheep and the processing method, way of marketing and storage of wool and economical analysis in the collective feeding of sheep

鄭鉉丞,姜奉泰,李炳五 진주산업대학교 1972 論文集 Vol.9 No.-

This is the report for 1971 of the third year project among the three years plan on the development of sheep range in Mt. Chiri. To investigate the effect of native grasses in Mt. Chiri on the breeding percentage of sheep this experiment was carried out from March 22, 1971 to March 21, 1972. Numbers of experimental animal used in this experiment were 12. Furthermore, the processing method of wool, marketing, economical analysis in the collective feeding and storage were investigated in cooperation with this experiment. The results obtained here were as follows; 1. For the processing method of wool, there are two ways; one of the processing method of wool is the self-processing method which follows the easy method of wool processing and another of the processing method of wool exchange with the good of wool texture company which follows the charge processing method of wool. 2. For the marketing route of wool, because the wool texture company can buy limitlessly wool, there are two ways to sell wool. The one of the way is the direct sell method of wool to the wool texture company and the other of the way is the sell method of wool via the route of circulation mechanism. 3. In the case of economical analysis for the collective feeding of sheep, if farms could raise 3,000 of sheep in the method of collective feeding it could get net income of 150,000 to 300,000 won for 52 days per farm per year. 4. For the storage of wool, to attach of wool fat must be needed and in the case of short period storage, wool must be placed in the arid place and in the case of long period storage, wool should be prevented from the attack of insect and rat, attachment of spurious article such as dust, decrease of weight and denaturation of wool fat. 5. The breeding percentage of sheep fed only native herbages plant was 60%.

地被狀態의 差異에 따른 浸透能 比較

陳鉉五 경희대학교 부설 식량자원개발연구소 1993 硏究論文集 Vol.14 No.-

同一立地條件 下에서 分布하고 있는 地被狀態의 差異에 따른 浸透能의 比較·檢討를 目的으로 硏究를 遂行하였던 바 다음과 같은 結果를 얻었다. 1. 林地와 裸地의 浸透能 比較에서 各各 120∼210㎜/hr의 값을 나타내어 裸地에 比하여 林地의 浸透能이 良好하였다. 2. 林地의 地被狀態를 區分하여 闊葉樹林과 針葉樹林의 浸透能比較에서는 闊葉樹林의 浸透能이 良好하였으며, 針葉樹林의 樹種間 比較에서는 잣나무, 落葉松, 리기다林 順으로 浸透能이 良好하였다. 3. 林地에 있어서 Ao 除去狀態에서의 浸透能은 自然狀態에서의 浸透能에 比하여 5∼25㎜/hr의 減少를 보였으나, 잣나무林에서는 菌絲網層의 發達로 오히려 증가하는 傾向을 보였다. 4. 浸透能에 關與하는 土壤의 性質은 表層土의 最小容器量(0.706^(**))과 有機物(0.638^(**))로 나타났다. This study was carried out to investigate the comparison of the infiltration capacity at five land-cover types(P.koratensis, P.rigida, L leptolepis, broad-leaved forest and bare land) having similar topographic factors. The results can be summarized as follows. 1. According to the results of measurement there was found a clear difference in the infiltration capacities between forest land and bare land. The infiltration capacity of the forest land and that of the bare land were 120∼210㎜/hr, 100㎜/hr, respectively. 2. When the cover type was subdivided, it was found that the infiltration capacity of the broad-leaved forest was higher than that of the needle-leaved forest. Each tree species of needle-leaved forest could be arranged in the following order of high infiltration capacity: P koraiensis>L leptolepis>P rigida 3. In the measurement of exposed condition on the ground surface, the was in filtration capacity decreased 5∼25㎜/hr compared with the natural condition in general. On the contrary, at the P. koraiensis forest, it was increased by containing the mycelium net in the litter there. 4. As to the relation between the infiltration capacity and the soil properties, high correlations for the infiltration capacity was recognized among the minimum air capacity(0.706^(**))and organic matter(0.638^(**))in the surface soil.

삼나무의 생장과 침엽 및 토양양분 조성과의 관계

진현오,오종민 경희대학교 환경연구소 1998 環境硏究 論文集 Vol.8 No.-

This study was carried out to investigate the chemical properties of the soils and nutrient concentrations of the needles at the different site quality from the established Japanese cedar (Cryptomeria japonica) forests in Cheju island. Major results can be summarized as follow. 1. The nutrient concentration in needles was not correlated with needle-type and tree height growth. 2. A significant relationship was found to exist between site quality and exch Ca exch Mg, avail. K in the surface soil and N, K, Ca concentration in the needle. 3. Exch. Ca, exch. Mg and avail. K in the surface soil was related closely to N, K, and Ca concentration in the needle. 4. Appropirate concentration of chemical properties in the surface soil and current year's needle are exch, C04.0, exch. Mg>2.0, avail. K>0.5(me/l00g) and N>1.5, K>0.8, Ca>1.5(%), resepectively.