적층압축에 의한 접합재의 경계면 성장거동에 대한 수치 시뮬레이션

정태훈,류제구,後藤學 서울産業大學校 1997 논문집 Vol.45 No.1

Under plane strain compression, of two blocks with sawtoothed interface, the sawtooth growth occurred. We presumed in the previous paper that such growth was caused by the shear-band formation starting from the tip of sawtooth and its degree depended on the material properties of the block. In this paper, Compression in the case where similar blocks are twinned and also compression in the case where dissimilar blocks are twinned variously are carried out in the condition of lubricated interface. Further, in the latter, compression where the interface is degreased is also performed. The degree of growth is experimentally investigated. Moreover, numerical simulations are carried out by the elastic-plastic FEM for the case of the dissimilar blocks with the initial sawtooth angle of 60℃ . In the experiment, the harder material yields larger growth than the softer one, and the growth in the case of initial sawtooth angle 60℃ is greater than that of 90℃ . Larger ratio of total height to sawtooth height gives larger growth in comparison with the previous experimental result. In the case where the dissimilar blocks are twinned, larger difference between material properties leads smaller growth, and the degreased interface leads smaller growth than that in the lubricated one. Furthermore, by the simulation of compression where dissimilar blocks are twinned, it is confirmed that the tendency of the general deformation pattern is very similar to the experiment.

착화제와 유기산이 Wistar rat체내의 Sr 분포에 미치는 영향

이기호,이제호,박상윤,이승훈,유용운,윤택구 대한방사선 방어학회 1990 방사선방어학회지 Vol.15 No.2

Wistar rat에 85SrCl2를 꼬리 정맥에 주사하여 체내 기관과 혈액 내 분포, 잔존율을 조사하였고 착화제와 유기산을 투여하여 혈장 단백질에 결합하는 Sr양의 변화를 측정하였다. 혈액내에서 Sr은 혈장에 60%, 세포에 40%부착되어 이동하였다. 혈장에 존재하는 Sr중 약 50%정도는 혈장 단백질과 결합한 상태였고, 세표에는 세포 표면에 가볍게 부착되어 있었다. Erythrocyte나 granulocyte보다 lymphocyte에 많은 양의 Sr이 부착되어 있었다. 투여후 초기 1시간 이내에 혈액 내에서 급격히 감소하여 뼈에 침착되었다. 이때 각 기관에서도 Sr의 잔존율은 24시간 이내에 크게 감소하였고, 뼈로 침착된 Sr은 24시간 이후에 서서히 감소하였다. 착화제 EDTA, EGTA 및 DTPA를 투여한 경우, 혈장 단백질에 결합하는 Sr의 양은 대조군의 57%에서 27-33%로 감소하였으며 citrate 및 oxalate의 투여시는 이값이 19%와 40%로 각각 감소하였다. 85SrCl2 was injected to the tail vein of Wistar rats and investigated its distribution and clearance in the tissues and blood. We also measured the changes in Sr binding to the blood plasma protein by administrating chelating agents and organic acids. For the blood, 60% of the Sr occurred in the plasma and 40% on the cell membrane. Fifty percent of Sr in the blood plasma was bound to plasma protein. Sr on the cell membrane seemed to be bound loosely. The binding in the lymphocyte was higher than in the erythrocyte and granulocyte. Within one hour Sr was quickly disappeared from the blood stream, to be accumulated in the bone. Twenty four hours after the injection, Sr decreased rapidly in the organs of soft tissue, but slowly in the bone. The binding of Sr to plasma protien decreased from 57% of the control to 27-33% in the group treated with chelating agents. EDTA. EGTA and DTPA and to 19% and 40% in the groups treated with organic acids, citrate and oxalate, respectively.

Linkage Structure Analysis of Barley and Oat β-Glucans by High Performance Anion Exchange Chromatography

Je-Hoon Ryu,Dong-Hyung Yoo,Byung-Hoo Lee,Suyong Lee,Mi Hyun Joo,Sang-Ho Yoo 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.1

Cereal β-glucans, linked essentially by mixed β-(1,4/1,3) glycosidic bonds, were extracted, purified, and structurally identified. Previously chemical structure of barley β-glucans was characterized from 3 varieties of ‘Gang’, ‘Ohl’, and ‘Gwangan’, and the (1,4)/(1,3) linkage ratio of the β-glucans was identical. In this study, β-glucans from 1 barley (‘Chal’) and 3 oat (‘Ohl’, ‘Samhan’, and ‘Donghan’) varieties were structurally scrutinized, and the linkage pattern of total 7 cereal β-glucans was compared. The amount of 2 major 3-O-β-cellobiosyl-D-glucose (DP3) and 3-O-β-cellotriosyl-D-glucose (DP4) from barley and oat accounted for only 66.6-73.3 and 68.12-81.89% of water-extractable β-glucan fractions, and the (1,4)/(1,3) linkage ratios of both barley and oat β-glucans were within very narrow range of 2.27-2.31 and 2.38-2.39, respectively, among the cultivars tested. Structural difference in the cereal β-glucans was evident when DP3:DP4 ratio in the β-glucan structure was compared. As a result, this ratio was significantly greater for barley β-glucan (2.26-2.74) than for oat (1.54-1.66). Chal-B had the greatest DP3 to DP4 ratio among the samples, which in turn reflected the least amount of (1,4)-linkages.

Production and characterization of digestion-resistant starch by the reaction of Neisseria polysaccharea amylosucrase

Ryu, Je-Hoon,Lee, Byung-Hoo,Seo, Dong-Ho,Baik, Moo-Yeol,Park, Cheon-Seok,Wang, Ren,Yoo, Sang-Ho WILEY-VCH Verlag 2010 Die Stärke Vol.62 No.5

<P>Recombinant amylosucrase (200 U/mL) from Neisseria polysaccharea was used to produce digestion-resistant starch (RS) using 1–3% (w/v) corn starches and 0.1–0.5 M sucrose incubated at 35°C for 24 h. Characterization of the obtained enzyme-modified starches was investigated. Results show that the yields of the enzyme-modified starches were inversely proportional to the original amylose contents of corn starches. After enzymatic reaction, insoluble RS contents increased by 22.3 and 20.7% from 6.9% of waxy and 7.7% of normal corn starches, respectively, using 3.0% starch as acceptor and 0.3 M sucrose as donor, while amylomaize VII showed the lowest increase (8.5%) in RS content. The crystalline polymorph of these enzyme-modified starches resulted in the B-type immediately after enzymatic reaction. The enzyme-modified starches displayed higher melting peak temperatures (85.6–100.6°C) compared to their native starch counterparts (70.1–78.4°C). After enzymatic reaction, pasting temperature increased in waxy (71.9 → 77.6°C) and normal corn starches (75.3 → 80.6°C), and the peak viscosity of waxy corn starches increased from 264 to 349 RVU, whereas that of normal corn starches decreased from 235 to 66 RVU.</P>

라즈베리파이를 이용한 메카넘 휠 스마트 휠체어에 대한 연구

류정규(Ryu Jeong Gyu),류환규(Ryu Hwan Gyu),이성훈(Lee Sung Hoon),변영훈(Byun Young Hoon),전상식(Jeon Sang Sik),제희상(Je Hee Sang) 한국통신학회 2017 한국통신학회 학술대회논문집 Vol.2017 No.11

Variability of Soil Water Content, Temperature, and Electrical Conductivity in Strawberry and Tomato Greenhouses in Winter

Ryu, Dong-Ki,Ryu, Myong-Jin,Chung, Sun-Ok,Hur, Seung-Oh,Hong, Soon-Jung,Sung, Je-Hoon,Kim, Hak-Hun Korean Society for Agricultural Machinery 2014 바이오시스템공학 Vol.39 No.1

Purpose: Monitoring and control of environmental condition is highly important for optimum control of the conditions, especially in greenhouses and plant factories, and the condition is not uniform within the facility. Objectives of the study were to investigate variability in soil water content and to provide information useful for better irrigation control. Methods: Experiments were conducted in a strawberry-growing greenhouse (greenhouse 1) and a cherry tomato-growing greenhouse (greenhouse 2) in winter. Soil water content, electrical conductivity (EC), and temperature were measured over the entire area, at different distances from an irrigation pump, and on ridge and furrow areas. Results: When measured over the entire greenhouse area, soil water content decreased and temperature and electrical conductivity increased over time from morning to afternoon after irrigation. Water content decreased by distance from the irrigation pump up to 70 m and increased after that, and temperature showed an inverse pattern. Soil water contents on the ridge were lower than those on the furrow, and the differences were 10.2~18.4%, indicating considerable variability. The lowest EC were observed on the furrow and highest values were observed on the ridge. Soil water contents were less and temperature levels were greater at the window side than in the center locations. Conclusions: Selection of number and location of soil water content sensor would be the first step for better water content monitoring and irrigation control. Results of the study would provide basic data useful for optimum sensor location and control for underground greenhouse environment.

Kriging Interpolation Methods in Geostatistics and DACE Model

Je-Seon Ryu,Min-Soo Kim,Kyung-Joon Cha,Tae Hee Lee,Dong-Hoon Choi 대한기계학회 2002 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.16 No.5

In recent study on design of experiments, the complicate metamodeling has been studied because defining exact model using computer simulation is expensive and time consuming. Thus, some designers often use approximate models, which express the relation between some inputs and outputs. In this paper, we review and compare the complicate metamodels, which are expressed by the interaction of various data through trying many physical experiments and running a computer simulation. The prediction model in this paper employs interpolation schemes known as ordinary kriging developed in the fields of spatial statistics and kriging in Design and Analysis of Computer Experiments (DACE) model. We will focus on describing the definitions, the prediction functions and the algorithms of two kriging methods, and assess the error measures of those by using some validation methods.

彈塑性 有限要素法에 衣한 平板의 Punch Indenting 應力解析

柳濟九,鄭太勳 서울産業大學校 1990 논문집 Vol.31 No.1

In this study a method is presented for the finite deformation, elastoplastic analysis of two-dimensional plane strain by the finite element method. A computer program based on the updated lagrangian method has been developed. The numerical example presented in this paper show that punch indenting are analyzed in the experimental equation in regard to stainless steel. The punch indenting problem of half-infinite plane-plate is analyzed by the 6 steps incremental iteration equibrium process. The distribution of normal stress and shearing stress are calculated to each step of the deformed configuration and the growing process of plastic field. But under the above assumption, the possibility of analyzing some examples is presented.

A Case of Paraneoplastic Limbic Encephalitis Associated with Small Cell Lung Cancer

Ryu, Ja Young,Lee, Seung Hyeun,Lee, Eun Joo,Min, Kyung Hoon,Hur, Gyu Young,Lee, Sung Yong,Kim, Je Hyeong,Lee, Sang Yeub,Shin, Chol,Shim, Jae Jeong,In, Kwang Ho,Kang, Kyung Ho,Yoo, Se Hwa The Korean Academy of Tuberculosis and Respiratory 2012 Tuberculosis and Respiratory Diseases Vol.73 No.5

Paraneoplastic limbic encephalitis (PLE) is a rare syndrome characterized by memory impairment, affective and behavioral disturbances and seizures. Among many different neoplasms known to cause PLE, small cell lung cancer (SCLC) is the most frequently reported. The pathogenesis is not fully understood but is believed to be autoimmune-related. We experienced a patient with typical clinical features of PLE. A 67-year-old man presented with seizure and disorientation. Brain magnetic resonance imaging demonstrated high signal intensity in the bilateral amygdala and hippocampus in flair and T2-weighted images suggestive of limbic encephalitis. Cerebrospinal fluid tapping revealed no evidence of malignant cells or infection. Positron emission tomography/computed tomography showed a lung mass with pleural effusion and a consequent biopsy confirmed the diagnosis of PLE associated with SCLC. The patient was subsequently treated with chemotherapy and neurologic symptoms gradually improved.

Electrocatalytic characteristics of Pt–Ru–Co and Pt–Ru–Ni based on covalently cross-linked sulfonated poly(ether ether ketone)/ heteropolyacids composite membranes for water electrolysis

Je-Young Woo,Kwang-Mun Lee,Bong-Chul Jee,Cheol-Hwi Ryu,Cheol-Hun Yoon,Jang-Hoon Chung,Yong-Ryul Kim,Sang-Bong Moon,An-Soo Kang 한국공업화학회 2010 Journal of Industrial and Engineering Chemistry Vol.16 No.5

Membrane electrode assemblies (MEAs) of covalently cross-linked sulfonated poly(ether ether ketone)(CL-SPEEK)/heteropolyacids (HPAs) composite polymer with platinum-based alloys such as Pt–Ru–Co and Pt–Ru–Ni were prepared and their electrochemical properties for water electrolysis were investigated. The HPAs, which were used in the composite membranes, were tungstophosphoric acid (TPA) (the part of TPA data was permitted by the previous authors), molybdophosphoric acid (MoPA),and tungstosilicic acid (TSiA). The MEAs with Pt–Co, Pt–Ru–Co, and Pt–Ru–Ni in the anode catalyst layer were prepared by means of a non-equilibrium impregnation–reduction (I–R) method. The electrocatalytic properties of composite membranes, such as the cell voltage and coulombic charge in CV, were in the following order: CL-SPEEK/MoPA40 > CL-SPEEK/TPA30 > CL-SPEEK/TSiA40 (wt%). For the optimum cell applications of water electrolysis, the cell voltage of Pt/PEM/Pt–Ru–Co (Electrodeposited (Dep)-MoPA) MEA with a CL-SPEEK/MoPA40 membrane was 1.70 V at 80 8C and 1 A cm2, and this voltage carried a value lower than that of 1.81 V of Nafion 117. In addition, the observed activity of Pt–Ru–Co (75:12:13 by EDX) is a little higher than that of Pt–Ru–Ni (79:10:11 by EDX). The mean coulombic charge and activity enhancement of Pt–Ru–Co catalysts, with and without electrodeposition, showed the same CV profiles of the Pt–Ru–Co catalysts and were in the following order: Nafion 117 < CL-SPEEK/TSiA40 < CL-SPEEK/TPA30 < CL-SPEEK/MoPA40. The current density peak of electrodeposited electrodes was a little better than those of inactivated electrodes on the same membranes. The current peak by Pt–Ru–Co with CL-SPEEK/MoPA40 (Dep-MoPA) is more than about three times as high as those of Pt electrodes on the same membranes. 2010 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.