http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
충돌분무의 액적 거동에 미치는 비등방성 난류특성의 영향에 대한 수치해석 연구
고권현(G. H. Ko),유홍선(H. S. Ryou) 한국전산유체공학회 2003 한국전산유체공학회지 Vol.8 No.4
It is an aim of this study to perform extensive numerical study for analyzing the anisotropic turbulence effects on spatial and temporal behaviors of droplet for impinging sprays. The turbulence model of Durbin is used for comparisons with the k-E model. The turbulence-induced dispersions of droplets are consider to describe the anisotropy of turbulence effectively and spray/wall interactions are simulated using the model of Lee and Ryou. Present study investigates the overall and the internal structures of impinging diesel sprays such as spray shapes, radius and height of wall sprays, Sauter mean diameter (SMD), local droplet velocity, and local gas velocity and compared the results with experimental data by two adopted turbulence models. When the anisotropy effect of turbulence is included, better predictions for both gas and droplet tangential velocities are obtained, compared to the k-ε model. It is concluded that anisotropic effect of turbulence should be considered for simulating impinging diesel sprays.
Host People's Kindness and Migrant Workers' Cultural Adaptation: Evidence from South Korea
Jihyun Ryou(Jihyun Ryou),Sang-Yeon Kim(Sang-Yeon Kim) 한국학술연구원 2022 Korea Observer Vol.53 No.4
This study purports to determine the predictors of migrant workers' cultural adaptation in South Korea. In the main, we examined the extent to which the level of inter-/intracultural socializing, exposure to local/native media, and host culture receptivity affect the level of cultural adaptation in cognitive, affective, behavioral domains. Potential impacts of demographic factors (e.g., age, sex, ethnicity, marital status, living alone vs. with family, education level, residency in years, perceived cultural similarity) were also explored. To find answers to the research questions, a total of 634 migrant workers from 37 different nations were reached using a snowball sampling. Surveys were collected in 12 districts of Seoul, the capital of South Korea, and 21 adjacent metropolitan areas. Results indicate that intercultural interaction with host people and media exposure to local contents tend to help improve their knowledge about South Korea (e.g., language, culture). With all else equal, migrant workers treated kindly by Koreans at the workplace and in service sectors, and those living with family, compared to those who live alone, tended to enjoy a greater satisfaction with work and life in South Korea and were more willing to stay. Practical implications for Korean policymakers include encouraging competent migrant workers to move together with the family, making administrative efforts to further simplify the documentation process, and initiating public campaigns to raise host culture receptivity among Korean citizens.
Ryou, Hong-Sun,Lee, Seong-Hyuk,Ko, Gwon-Hyun,Hong, Ki-Bae The Korean Society of Mechanical Engineers 2001 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.15 No.7
The present article presents an extension to the computational model for spray/wall interaction and liquid film processes that has been dealt with in the earlier studies (Lee and Ryou, 2000a). The extensions incorporate film spread due to impingement forces and dynamic motion induced by film inertia to predict the dynamic characteristics of wall films effectively. The film model includes the impingement pressure of droplets, tangential momentum transfer due to the impinging droplets on the film surface and the gas shear force at the film surface. Validation of the spray/wall interaction model and the film model was carried out for non-evaporative diesel sprays against several sources of experimental data. The computational model for spray/wall interactions was in good agreement with experimental data for both spray radius and height. The film model in the present work was better than the previous static film model, indicating that the dynamic effects of film motion should be considered for wall films. On the overall the present film model was acceptable for predication of the film radius and thickness.
The Effects of Water Mist on the Compartment Fire
Ryou, Hong-Sun,Kim, Sung-Chan The Society of Air-Conditioning and Refrigerating 2004 International Journal Of Air-Conditioning and Refr Vol.12 No.1
The present study investigates the fire suppression characteristics using a water mist fire suppression system. Numerical simulations of fire suppression with water mist are performed with considering the interaction of fire plume and water spray. The predicted temperature fields of smoke layer are compared with those of measured data. Numerical results agree with the experimental results within $10^{\circ}C$ in the case without water mist. In the case of fire suppression with water mist, numerical results do not predict well for temperature field in the gradual cooling region after water mist injection. But the predicted results of initial fire suppression are in good agreement with those of measured data. The reason for the discrepancy between predicted and measured data is due to the poor combustion modeling during the injection of water mist. More elaborate models for numerical simulation are required for better predictions of the fire suppression characteristics using water mist.
Numerical Evaluation of Crashworthiness of Automotive Sheets
Ryou, Han Sun,Lee, Myoung Gyu,Kim, Chong Min,Chung, Kwan Soo Trans Tech Publications, Ltd. 2007 Key Engineering Materials Vol.345-346 No.-
<P>Crash simulations were performed for automotive sheets. To understand the influence of crystal structures in sheet materials on crashworthiness, the effect of the yield function shape was studied by adopting the recently developed non-quadratic anisotropic yield surface, Yld2004-18p. The effect of the back-stress was also investigated by comparing simulation results obtained for the isotropic, kinematic and combined isotropic-kinematic hardening laws based on the modified Chaboche model. In addition, the effects of anisotropy and sheet thickness on crashworthiness were evaluated.</P>
Ryou, Myung-Hyun,Han, Young-Dal,Lee, Je-Nam,Lee, Dong-Jin,Park, Jung-Ki The Korean Electrochemical Society 2008 한국전기화학회지 Vol.11 No.3
The multilayered membrane for lithium rechargeable batteries based on poly (vinylidene fluoride) (PVdF) is prepared with the coated layer containing nano-sized filler. The prepared membranes were subjected to studies of mechanical strength, morphology, interfacial stability, impedance spectroscopy, ionic conductivity, and cycle performance. The localized inorganic filler in the PVdF composite membrane rendered mechanical strength much reduced because of its low stretching ratio and it results in around half value of the mechanical strength of highly stretched PVdF membrane. In order to achieve high ionic conductivity and interfacial stability without sacrificing high mechanical strength, coating layer with nano-filler was newly introduced to PVdF membrane. The ionic conductivity of the coated membrane was 1.03 mS/cm, and the interface between the coating layer and PVdF membrane was stable when the membrane was immersed into liquid electrolyte. The discharge capacity of the cell based on nano-filler coated PVdF membrane was around 91% of the initial discharge capacity after 250 cycles, which is an improvement in cycle performance compared to the case for the non-coated PVdF membrane.
Edge-functionalization of armchair graphene nanoribbons with pentagonal-hexagonal edge structures
Ryou, Junga,Park, Jinwoo,Kim, Gunn,Hong, Suklyun Institute of Physics 2017 Journal of Physics, Condensed Matter Vol.29 No.24
<P>Using density functional theory calculations, we have studied the edge-functionalization of armchair graphene nanoribbons (AGNRs) with pentagonal-hexagonal edge structures. While the AGNRs with pentagonal-hexagonal edge structures (labeled (5,6)-AGNRs) are metallic, the edge-functionalized (5,6)-AGNRs with substitutional atoms opens a band gap. We find that the band structures of edge-functionalized (5,6)-<I>N</I>-AGNRs by substitution resemble those of defect-free (<I>N</I>-1)-AGNR at the Γ point, whereas those at the <I>X</I> point show the original ones of the defect-free <I>N</I>-AGNR. The overall electronic structures of edge-functionalized (5,6)-AGNRs depend on the number of electrons, supplied by substitutional atoms, at the edges of functionalized (5,6)-AGNRs.</P>
RYOU, CHONGSUK,CHUNG, TAEYOUNG,KWON, MOOSIK 한국미생물 · 생명공학회 2001 Journal of microbiology and biotechnology Vol.11 No.6
The gene coding for a Lepidoptera-specific insecticidal crystalline (or control) protein (ICP), recognized as cryLAc, from Bacillus thuringiensis subsp. kurstaki HD-73, was cloned into the vector pBluscript Ⅱ SK-, and then transformed in Escherichia coli DH5α. The clone was named EBtIAc and the chimeric phagemid, as pEBtIAc. Hyperexpression of CrylAc protoxin was observed in the extract of the culture of E. coli harboring pEBtIAc. Crystalline protoxin was purified by differential solubility. It was dissolved in alkaline pH, and exposed to trypsin to be activated. The molecular weights of the pro- and activated toxins on SDS-PAGE were estimated to be ca. 130 kDa and 60 kDa, respectively. The toxicity was tested by force-feeding larvae of gypsi moth (Lymantria dispar) with trypsinized protoxin. Using the batch of biologically active form of the toxin as an immunogen, anti-CrylAc antiserum was raised in a New Zealand white rabbit. Immunoglobulin G was fractionated from the serum by Protein-A sepharose affinity chromatography. Immunoreactivity of the antibody was examined by dot and Western blottings. It has been found that the anti-CryLAc antibody recognized the purified toxin at a level below a nanogram in terms of quantity. Using the antibody some of Bt-corns were able to be differentiated from tons of corn kernels which were imported from America as forage crops.