http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
중대뇌동맥류 결찰술에서 총경동맥의 일시적 결찰에 따른 동맥류 및 주요 동맥들의 혈류역학적 시뮬레이션
류상원(Sangwon Ryu),장경민(Kyoung-Min Jang),남택균(Taek-Kyun Nam),유재영(Jaiyoung Ryu) 대한기계학회 2023 대한기계학회 춘추학술대회 Vol.2023 No.11
Intracranial aneurysm refers to a disease in which the blood vessel wall, especially at the branching points of arteries within the brain, weakens and abnormally balloons out. In severe cases, when aneurysm ruptures, it can lead to subarachnoid hemorrhage, resulting in a high mortality rate. In this study, we investigated a surgical approach to reduce the diameter of the common carotid artery (CCA) on the side where the middle cerebral artery aneurysm had occurred for safe clipping. The results showed that as the diameter of the internal carotid artery was reduced, the internal pressure within the aneurysm decreased. When the diameter was reduced to 95%, the internal pressure within the aneurysm decreased by approximately 50% based on the Mean Arterial Pressure (MAP). Additionally, as the diameter of the common carotid artery decreased, there was increase in cerebral blood flow through the circle of willis leading to high Wall Shear Stress (WSS) in the anterior cerebral artery and middle cerebral artery.
서진호,오두병 한국통합생물학회 2022 Animal cells and systems Vol.26 No.3
A lysosome, an acidic membrane-bound organelle, contains hydrolytic enzymes to digest macromolecules for recycling. Many lysosomal enzymes (LEs) traffic to the lysosome through the mannose-6-phosphate (M6P)-dependent pathway. Some mannose residues of highmannose type N-glycans on LEs can be phosphorylated in the Golgi apparatus through twostep enzyme reactions. The consequent M6P moiety is recognized by M6P receptors (MPRs) on the trans-Golgi network membrane and delivered through the endo-lysosomal pathway. On the other hand, secreted LEs containing M6P glycans can be recaptured by MPRs on the plasma membrane and targeted to the lysosome. Enzyme replacement therapy (ERT) for lysosomal storage diseases exploits this M6P-MPR-dependent endocytosis to deliver recombinant enzymes to lysosomes. This review discusses various engineering and application technologies using M6P’s lysosomal targeting. Glyco-engineering for increasing M6P contents developed ‘Biobetter’ ERT enzymes with enhanced therapeutic efficacy. M6P-decorated peptides, proteins, liposomes, and nanoparticles have been developed for drug delivery and subcellular imaging. A recently developed lysosome-targeting chimera uses an M6P-based bifunctional binder to degrade specific extracellular and membrane proteins. The success and efficiency of M6P-based lysosomal targeting will boost further technological developments with new applications in the biomedical field.
가스터빈 블레이드 내부 냉각 유로 요철이 열전달 특성에 미치는 영향
정현우(Hyunwoo Jung),유재영(Jaiyoung Ryu) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11
The rib turbulator plays important role to remove the heat by enhancing heat transfer of coolant passage wall. Various author investigated the configuration of the rib turbulator by experiment and computational methods, however, their investigations were confined to low Reynolds number and very high rotation number while the present gas turbine in land-based power plant have been developing to achieve higher temperature and Reynolds number close to 500000. Therefore, we investigated the characteristics of fluid behavior and thermal transfer in rib turbulated coolant passage with high Reynolds number and rotating speed of 3600RPM using computational fluid dynamics (CFD) methods. The Nusselt number and friction factor were quantified for evaluating thermal characteristics and pressure drop. The averaged Nusselt number was almost equal in first passage but showed significant differences in second passage according to increase of Reynolds number. Moreover, smaller rib spacing induces better heat transfer but larger pressure loss.
FW-H 방법을 이용한 잠수함 표면 처리에 따른 소음 전산 해석
김승기(Seunggi Kim),유재영(Jaiyoung Ryu) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11
Submarine has been performed for national defense activities representatively. Underwater Radiated Noise (URN) which emitted during underwater vehicle operation is directly related to the survivability of the underwater vehicle. This study focused on examining the effects of surface treatment on noise aspects in submarine. Numerical simulations were conducted for two cases : smooth surface as a reference case, and V-type riblet. To solve the incompressible fluid flow passing the submarine, the Reynolds-averaged Navier-Stokes equation coupled with the k-ω SST turbulence model was used. As a result of examining the noise radiation around the submarine, it was confirmed that it was necessary to pay attention to the noise radiation effect in the middle part of the submarine body. And the results indicate that overall sound pressure level can be reduced about maximum 4 dB at far-field by applying riblet surface. This study provides more enhanced understanding about the surface design on underwater vehicles to reduce underwater radiated noise.
전산 소음 해석 기법을 이용한 잠수함 표면 처리에 따른 소음 효과 관찰
김승기(Seunggi Kim),유재영(Jaiyoung Ryu) 한국전산유체공학회 2021 한국전산유체공학회지 Vol.26 No.4
Submarine has been performed for national defense activities representatively as a multi-purpose underwater vehicle. Underwater Radiated Noise (URN) which emitted during underwater vehicle operation is directly related to the survivability of the underwater vehicle. This study focused on examining the effects of surface treatment on noise aspects in whole submarine body for the first time. Prior to the acoustic analysis on the submarine model, the acoustic analysis procedure using commercial CFD software was verified using a 2D cylinder model. Acoustic analysis on submarine model was conducted for two cases: smooth surface as a reference case, and a few micrometers of V-type applied riblet case. To solve the incompressible fluid flow passing the submarine, the Reynolds-averaged Navier-Stokes (RANS) equation coupled with the k-ω SST turbulence model was used. For acoustic analysis, the Ffowcs Williams and Hawkings acoustic analogy, which calculates flow-induced noise by designating a physical wall as a noise source, was used. The noise effects according to the surface treatment on submarine shape were examined by comparing overall sound pressure level (OASPL) between smooth and riblet case and the results indicate that noise around submarine shape was reduced about 4.3 dB in maximum on surface-treated area. However, when calculating OASPL excluding noise below 20 Hz, which is a frequency range where noise does not propagate, the noise tends to increased due to riblet shape. This study provides established procedure in acoustic analysis on whole submarine body and a new perspective that underwater radiation noise should be considered when designing surface treatment on submarine.