http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Shape Optimization of Flow Channels Using Lattice Boltzmann Method
Jungmin Park(박정민),Kyung Chun Kim(김경천) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12
A new optimality criterion algorithm is presented for producing modified shape designs for fluid flow inside channels. To compute the fluid motion in a channel, the Lattice Boltzmann Method (LBM) was used based on D2Q9 lattice spaces associated with the Bhatnagar-Gross-Krook (BGK) collision term. An experiential optimality method to design channels with the lowest pressure drop along the passage is introduced. The positions of solid cells and fluid cells are exchanged based on the strain rate tensor at the solid-fluid interface. To obtain the optimized shape, the cells are changed until the optimality condition is obtained with the restriction of constant fluid volume. Examples are presented to validate the algorithm, including an elbow tube as well as symmetrical and nonsymmetrical T-junction channels. The validation exercises demonstrate that the algorithm is suitable for optimal channel design.
확산 포집에 따른 Metal fiber filter의 포집 온도별 필터링 특성 고찰
석정민(Jungmin Seok),전광민(Kwang Min Chun),송순호(Soonho Song),이세영(Seyoung Lee) 한국자동차공학회 2014 한국자동차공학회 학술대회 및 전시회 Vol.2014 No.11
Soot particle deposition behavior of metal fiber filter has been studied with pressure drop and particle number concentration based filtration efficiency measured by SMPS. The filter type of TWP (Thin Web Pad) was applied to the study, with mean pore size of 18μm, and unit weight of 1.0 kg/m2. 3 deposition temperature range was set as 150℃, 250℃, 400℃, to examine the effect of particle approach velocity as a function of deposition temperature (equivalent to an approach velocity of 1.4 m/s, 1.7 m/s, and 2.2 m/s, respectively). Particles were generated by soot generator, with mode diameter of 85 nm and total number concentration of 3.69 x 1010/cm3. Total flow rate was 29.23 sLPM, and deposition time was 1h. The result showed that the initial pressure drop showed an increase in proportion to the deposition temperature, but filtration efficiency showed different tendency; inversely proportional to the temperature. This tendency was resulted from the pressure drop is a function of temperature, but number concentration based filtration efficiency was inversely proportional to the temperature, when particle diffusion is the dominant deposition mechanism in filtration process.
Comparative Biodistribution Study of Baculoviral and Adenoviral Vector Vaccines against SARS-CoV-2
Lee Hyeon Dong,Chun Jungmin,Kim Sehyun,Aleksandra Nowakowska,Lee Chanyeong,Yoon Doyoung,Lee Hee-jung,Kim Young Bong 한국미생물·생명공학회 2024 Journal of microbiology and biotechnology Vol.34 No.1
Various types of vaccines have been developed against COVID-19, including vector vaccines. Among the COVID-19 vaccines, AstraZeneca’s chimpanzee adenoviral vaccine was the first to be commercialized. For viral vector vaccines, biodistribution studies are critical to vaccine safety, gene delivery, and efficacy. This study compared the biodistribution of the baculoviral vector vaccine (AcHERV-COVID19) and the adenoviral vector vaccine (Ad-COVID19). Both vaccines were administered intramuscularly to mice, and the distribution of the SARS-CoV-2 S gene in each tissue was evaluated for up to 30 days. After vaccination, serum and various tissue samples were collected from the mice at each time point, and IgG levels and DNA copy numbers were measured using an enzyme-linked immunosorbent assay and a quantitative real-time polymerase chain reaction. AcHERV-COVID19 and Ad-COVID19 distribution showed that the SARS-CoV-2 spike gene remained predominantly at the injection site in the mouse muscle. In kidney, liver, and spleen tissues, the AcHERV-COVID19 group showed about 2– 4 times higher persistence of the SARS-CoV-2 spike gene than the Ad-COVID19 group. The distribution patterns of AcHERV-COVID19 and Ad-COVID19 within various organs highlight their contrasting biodistribution profiles, with AcHERV-COVID19 exhibiting a broader and prolonged presence in the body compared to Ad-COVID19. Understanding the biodistribution profile of AcHERV-COVID19 and Ad-COVID19 could help select viral vectors for future vaccine development.
화학사고 초기대응자를 위한 검지관식 탐지장비의 반응성 연구
Seung-young Ahn,JungMin Kim,Sungbum Kim,KwangSoo Chun,Jin-Seon Lee,Choonhwa Park 한국재난정보학회 2014 한국재난정보학회 논문집 Vol.10 No.1
화학사고 발생 시 현장 초기대응자들은 사고 원인물질과 농도를 신속하고 손쉽게 확인 하기 위한 방식으로, 미국 환경청(EPA) 초기대응팀에서도 널리 사용하고 있는 직독식 탐지장비를 이용하고 있다. 환경부에서는 검지관식 가스 탐지장비를 직독식 탐지장비로 이용하여 사고 발생 시 현장에서 이용하고 있고, 검지관식 가스탐지기는 신속한 원인 물 질 확인과 정밀한 분석 전에 전략적으로 대략적인 오염물질의 정량과 정성을 확인할 수 있는 유용한 장비이다. 그러나 현장 초기대응자들의 직독식 탐지장비의 사용방법에 대 한 이해 부족과 단순 수치로만 확인하려는 방식으로 인해 탐지결과의 정확성에 대한 의 문점을 늘 제기해 왔다. 본 논문에서는 사고 현장에서 정확한 탐지 결과를 얻기 위해 환경부에서 사용하고 있는 검지관식 가스탐지기인 Kitagawa와 Draeger 탐지기의 물질 반응성을 확인하여 초기 대응자들의 현장 탐지결과의 정확성을 높이고자 하였다. Chemical accidents are the cause of the accident site during the initial responders to quickly and easily see materials and concentration method for the U.S. Environmental Protection Agency(EPA) is widely used in the initial response team direct reading detection equipment used. Ministry of the tubular gas detection equipment to detect direct reading detection equipment used in the event of an accident scene, and shell-and-tube gas detector for rapid detection and identification and precise analysis of causative pollutants before about strategically can identify the quantitative and qualitative useful equipment. However, those who initially respond to the scene of a direct reading detection equipment and a simple lack of understanding of how to use the numbers only because of the way you want to check the accuracy of detection results have been raising questions about the increase . The scene of the accident in order to obtain an accurate detection results used in this paper, the Ministry of Environment of gas detectors detect tubular Kitagawa and Draeger detector tube to check the reactivity of the material on-site detection of early response of those who were to raise the accuracy of the results.
Direct Observation of Fe-Ge ordering in Fe<SUB>5-x</SUB>GeTe₂ Crystals and Resultant Helimagnetism
Trinh Thi Ly,Jungmin Park,Kyoo Kim,Hyo-Bin Ahn,Nyun Jong Lee,Kwangsu Kim,Tae-Eon Park,Ganbat Duvjir,Nguyen Huu Lam,Kyuha Jang,Chun-Yeol You,Younghun Jo,Se Kwon Kim,Changgu Lee,Sanghoon Kim,Jungdae Kim 한국자기학회 2021 한국자기학회 학술연구발표회 논문개요집 Vol.31 No.1
The van der Waals (vdW) ferromagnet compared to conventional ferromagnetic materials provides a unique configuration of magnetic interactions due to its quasi two-dimensional (2D) nature. The pair-exchange interaction is mainly established within the 2D plane, while magnetic coupling between interlayers is weak. Therefore, the vdW ferromagnets are ideal for 2D spintronic devices that show various emergent spin-orbit coupled phenomena with time reversal and inversion symmetry breaking. As a promising vdW ferromagnet, the Fe<sub>n</sub>GeTe<sub>2</sub> family (n = 3, 4, 5) was proposed based on its high T<sub>C</sub> (260 ~ 310 K) and large saturation magnetization. Recently, the unconventional magnetic properties of Fe<sub>5</sub>GeTe<sub>2</sub> have been explained with magnetic anisotropy or/and spin reorientation by the Fe atoms in Fe<sub>5</sub>GeTe<sub>2</sub>. However, the exact mechanism of such non-trivial magnetic behaviors is still unclear because it is also involved with the structural complexity in Fe<sub>5</sub>GeTe<sub>2</sub>. Therefore, systematic study for finding the correlation between such non-trivial magnetic behaviors and the atomistic structure of Fe<sub>5</sub>GeTe<sub>2</sub> is needed to realize room temperature spintronic devices with this new vdW ferromagnet. In this study, we explore atomistic structures of an Fe<sub>5-x</sub>GeTe<sub>2</sub> single crystal by low temperature scanning tunneling microscopy (STM) and its temperature dependent magnetic behaviors. Subset Fe layers in Fe<sub>5</sub>GeTe<sub>2</sub> are expected to play a major role in magnetic ordering. STM topography reveals √3×√3 superstructures on the cleavage surface of Fe<sub>5-x</sub>GeTe<sub>2</sub>, which are attributed to the ordering of Fe(1) layer. Intriguingly, observed √3×√3 ordering of Fe(1)-Ge pair breaks the inversion symmetry, which is an important microscopic origin of the antisymmetric exchange interaction, known as Dzyaloshinskii-Moriya interaction (DMI). The temperature dependent magnetization of Fe<sub>5-x</sub>GeTe<sub>2</sub> clearly shows commensurate-incommensurate transition, a typical helimagnetic behavior arising from the DMI, just below T<sub>C</sub> = 310 K. We also confirm that spin reorientation behaviors are observed within the ranges of 120 ~ 260 K and 20 ~ 100 K due to competition between helimagnetism and other collinear properties. Our findings suggest that the Fe<sub>5</sub>GeTe<sub>2</sub> crystal has helical magnetism with non-centrosymmetric ordering of Fe(1)-Ge pairs, which can be a source of topologically protected spin solitons to develop new types of topology-based spin devices.