S.D. Rats를 이용 1, 1-Dichloro-1-fluoroethane의 아민성 흡입독성 연구

김현영,이성배,임철홍,김철우,점용현,한정희,전윤석,최수영,강대봉,이용묵 한국환경독성학회 2002 환경독성보건학회지 Vol.17 No.1

There were no specific effects for test materials on Sprague-Dawley (S.D.) rats in clinical symptoms, amounts of food intakes, weight changes, laboratory findings, and pathology after whole body l, l-Dichloro-1 -fluoroethane (used as coolant, metal cleaner and solvents) exposure(0, 1,500, 3,000, and 6,000 ppm) for 13 weeks (6 hour/day, 5 days/week). However, the loss of capillary vessels in eyeball (pupil) was observed in a female rat among 6,000 ppm group. Though there was a tendency for MCHC (Mean Corpuscular Hemoglobin Concentration) in rat to be decreased (p<0.05), it was not regarded as abnormal because the values were within normal limits. In asthma-stimulation related evaluations, there was also a tendency for inflammatory cell counts in bronchoalveolar lavages to be increased. But it had no statistical significance, and also no dependency on sex and the exposed concentration. Based on this result, the non observed effect level (NOEL) induced by 1, 1-Dichloro-l -fluoroethene inhalation was evaluated in groups with 3,000 ppm below (S .D. Rats, 13 weeks). Finally, it was concluded that the short term exposal of 1, 1-Dichloro-l-fluoroethane is not considered as a asthma stimulant by inhalation despite of some study limitations such as test animals use and short-term exposure .

RT-LAMP를 이용한 콩황화일반모자이크바이러스의 진단

배대현, 이영훈, 김봉섭, 윤영남, 강범규, 최만수, 구성철, 김현태, 윤홍태, 이수헌, 백인열 忠北大學校 農業科學硏究所 2014 農業科學硏究 Vol.30 No.2

Soybean yellow common mosaic virus (SYCMV) has been recently reported, it has been occurred a lot with Soybean mosaic virus (SMV) and Soybean yellow mottle mosaic virus (SYMMV) in soybean field. SYCMV belongs to genus of Sobemovirus and induced viral symptoms with yellowing, mottle and mosaic. A reverse transcription loop-mediated isothermal amplification (RT-LAMP) method allowed one-step detection of gene amplification by simple procedure and needed only a simple incubator for isothermal template. This RT-LAMP method allowed direct detection of RNA from virus-infected plants without thermal cycling and gel electrophoresis. In this study, we designed RT-LAMP primers named SYCML-F3/B3/FIP/BIP from coat protein gene sequence of SYCMV. After the reaction of RTLAMP, products were identified by electrophoresis and with the detective fluorescent dye, SYBR Green I. under daylight and UV light. Optimal reaction condition was at 63 for 60min and the primers of RTLAMP showed the specificity for only SYCMV tested in this study.

개원의의 진료의뢰시 기대요인 및 만족도에 관한 연구 : 협력병원체제 여부를 중심으로

김동일,김해준,윤석준,문영배 한국의료QA학회 2002 한국의료질향상학회지 Vol.9 No.2

Background : This research, as a part of improving management process of college hospital in this rapidly changing circumstances, is searching for the actual state of private clinics referring patients to referral center including college hospitals. Methods : This research examined the sense of satisfaction and requesting degree in using referral center and by analyzing the correlation and differences among factors such as primary factors regarded as selecting ones in referring patients to a referral center in college hospital and expecting factors expected to be supported to patients and cooperative hospitals. Results : The main researched results are as follows. First, as for the primary factors, the differences between cooperative and uncooperative hospitals revealed the fact that choosing target hospital in accordance with cooperative relation and convenient process in referring patients are important. Second, satisfaction rates, analyzed from the paired t-test revealed kindness and convenience as the top priorities, while sending patients back again and benefit of supporting such as the use of facilities were revealed as the least satisfactory aspects, despite the fact that they should be fulfilled through actual service. Conclusion : The recognition of the practitioner is examined and analyzed in this research by examining primary factors in selecting college hospitals, expecting factors expected to be supported to patients and satisfaction degree, which are expected to be used as basic materials for the development of referral center of college hospitals.

RESEARCH ACTIVITIES ON A SUPERCRITICAL PRESSURE WATER REACTOR IN KOREA

Bae, Yoon-Yeong,Jang, Jin-Sung,Kim, Hwan-Yeol,Yoon, Han-Young,Kang, Han-Ok,Bae, Kang-Mok Korean Nuclear Society 2007 Nuclear Engineering and Technology Vol.39 No.4

This paper presents the research activities performed to date for the development of a supercritical pressure water-cooled reactor (SCWR) in Korea. The research areas include a conceptual design of an SCWR with an internal flow recirculation, a reactor core conceptual design, a heat transfer test with supercritical $CO_2$, an adaptation of an existing safety analysis code to the supercritical pressure condition, and an evaluation of candidate materials through a corrosion study. Methods to reduce the cladding temperature are introduced from two different perspectives, namely, thermal-hydraulics and core neutronics. Briefly described are the results of an experiment on the heat transfer at a supercritical pressure, an experiment that is essential for the analysis of the subchannels of fuel assemblies and the analysis of a system safety. An existing system code has been adapted to SCWR conditions, and the process of a first-hand validation is presented. Finally, the corrosion test results of the candidate materials for an SCWR are introduced.

Distribution aspects of organisms by NGS analysis in soybean breeding field

Yeong-Hoon Lee,Dae-Hyeon Bae,Young-Nam Yoon,Man-Soo Choi,Hyun-Young Kim,Beom-Kyu Kang,Hyun-Tae Kim,Hong-Tae Yun,Su-Heon Lee,Jea-Sun Moon,InYoul Baek 한국육종학회 2014 한국육종학회 심포지엄 Vol.2014 No.07

Generally, the virus was detected by the ELISA using the serological method and RT-PCR based on the genetic information. Recently, NGS (next-generation nucleotide sequencing) has been used in genome analysis and diseases diagnostics. To identify distribution aspects of viruses, we collected diseased samples twice in soybean breeding field. After extraction of total RNA from the collected bulk samples, RNA was sequenced by the NGS method. The NGS data were analyzed using the bioinformatics software. With newly produced NGS data, the identification of distribution aspects of organisms in field was estimated in this study. Sequence based identification method should be more accurate diagnostic tools of the target diseases and be able to predict occurrence of potential and new pathogens. NGS method will also provide the basic data by identifying the distribution of using bacteria. In this study, we analyzed the extracted RNA from the collection of approximately 3000 samples. Consequently, we confirmed the following types: the 7,089 kinds of bacteria including Burkholderiaceae, the 13,397 kinds of Eukaryota, the 952 kinds of viruses from the first bulk samples, the 4,160 kinds of bacteria including Burkholderiaceae, the 10,475 kinds of Eukaryota, and the 576 kinds of viruses from the second bulk samples

Assessment of low-Reynolds number <i>k</i>-<i>ε</i> turbulence models against highly buoyant flows

Bae, Yoon-Yeong,Kim, Eung-Seon,Kim, Minhwan Elsevier 2017 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.108 No.1

<P><B>Abstract</B></P> <P>Low-Reynolds-number <I>k</I>-<I>ε</I> turbulence models have been successfully used by numerous researchers in various applications. It has been found that the Myong-Kasagi model (MK) among them outperforms in simulations of thermal-fluid fields at supercritical pressures and near the corresponding pseudo-critical temperature. However, they are used as is without a clear understanding of the cause of the good performance. In this paper, several well-known low-Reynolds-number turbulence models, including MK, are critically reviewed against DNS data and RANS calculation results to find the reasons, if any exist, for the superiority of MK model.</P> <P>The most outstanding factor identified may be the fact that MK introduced the Taylor microscale as the near-wall length scale and combined it with the integral length to result in a combined turbulence length scale, which is valid over the entire range of a turbulent boundary layer. The eddy viscosity formula with the incorporation of the turbulence length scale is naturally expected to provide a better representation of flows with strong buoyancy due to wall heating, especially in the near-wall region, where the buoyancy effect mainly occurs. As a result, MK-simulated highly buoyant flows showed excellent agreement with experimental data when applied with the property-dependent turbulent Prandtl number and shear-stress-dependent damping length. A comparison with DNS data of the turbulence data obtained from RANS calculations with MK also showed a good agreement.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Varying damping length and property-dependent turbulent Prandtl number were introduced. </LI> <LI> An assessment of the modified low-Reynolds-number turbulence models was made. </LI> <LI> Taylor microscale was behind the good performance of the Myong-Kasagi model. </LI> </UL> </P>

Numerical simulation of upward flowing supercritical fluids using buoyancy-influence-reflected turbulence model

Bae, Yoon-Yeong,Kim, Eung-Seon,Kim, Minhwan Elsevier 2017 Nuclear engineering and design Vol.324 No.-

<P><B>Abstract</B></P> <P>The mechanism behind heat transfer deterioration, occurring in fluids at supercritical pressures under particular conditions accompanying strong property variations, is not fully understood. The numerical simulations employing RANS type turbulence modelings have never succeeded in reproducing the thermal field of fluids under such conditions, although some success in particular cases has been reported, since the widely-used turbulence models do not account for the property variations and consequential boundary layer deformation. The authors recently reported that an introduction of varying dimensionless damping length (<I>A</I> <SUP>+</SUP>) as a function of the shear stress ratio between the wall and boundary layer edge into a turbulence model greatly improved the RANS type numerical simulation of highly buoyant flows. In this paper, the authors attempted to directly integrate the momentum equation under appropriate assumptions and approximations, and to establish a functional relation between <I>A</I> <SUP>+</SUP> and shear stress in the buffer layer ( <SUB> τ <SUB> δ t </SUB> </SUB> ). The introduction of <I>A<SUP>+</SUP> </I> as a function of <SUB> τ <SUB> δ t </SUB> </SUB> in the eddy viscosity formula in addition to the property-dependent turbulent Prandtl number, which was proposed earlier by the first author, resulted in numerical simulations of supercritical fluid with strong buoyancy agreeing excellently with the experimental data.</P>

RESEARCH ACTIVITIES ON A SUPERCRITICAL PRESSURE WATER REACTOR IN KOREA

YOON-YEONG BAE 한국원자력학회 2007 Nuclear Engineering and Technology Vol.39 No.4

This paper presents the research activities performed to date for the development of a supercritical pressure water-cooled reactor (SCWR) in Korea. The research areas include a conceptual design of an SCWR with an internal flow recirculation, a reactor core conceptual design, a heat transfer test with supercritical CO2, an adaptation of an existing safety analysis code to the supercritical pressure condition, and an evaluation of candidate materials through a corrosion study. Methods to reduce the cladding temperature are introduced from two different perspectives, namely, thermal-hydraulics and core neutronics. Briefly described are the results of an experiment on the heat transfer at a supercritical pressure, an experiment that is essential for the analysis of the subchannels of fuel assemblies and the analysis of a system safety. An existing system code has been adapted to SCWR conditions, and the process of a first-hand validation is presented. Finally, the corrosion test results of the candidate materials for an SCWR are introduced.

강한 부력을 받는 초임계압 유체의 난류 Prandtl 수

배윤영(Yoon Yeong Bae),김응선(Eung Seon Kim),김민환(Minhwan Kim) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.4

큰 밀도구배를 가진 유체 유동의 난류점성 모델

배윤영(Yoon-Yeong Bae),김응선(Eung-Seon Kim),김민환(Minhwan Kim) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12

In the numerical simulation of a fluid at supercritical pressure flowing upward in vertical heated channels, difficulties arise due to the dramatic variation of physical properties, especially density, when fluid temperature crosses the pseudocritical temperature. Many different turbulence models were tried to simulate the fluid flo w under strong property (especially density) variation, but never succeeded in reproducing experimental data. This failure is considered to be caused by ineptness of the presently-available turbulence models in the simulation of strong property-varying fluids. In the present study a new eddy viscosity model is presented, which adopted a different approach in using the length and time scales rather than the velocity and length scales. The new eddy viscosity model also incorporated the influence of density gradient. With the new models, fluid flows accompanying strong density gradient were successfully simulated, and satisfactorily agreed with the experimental data.