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The Effect of Non-equilibrium Condensation on the Drag Coefficient in a Transonic Airfoil Flow

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Journal of Thermal Science 2012年第6期21卷 518-524页

作者： I.W.Kim M.M.A.Alam S.J.Lee y.D.kwon S.B.kwon School of Mechanical Engineering Kyungpook Nat.Uni.1370Sankyuk-dongDaegu 702-701Korea Dept.of Advanced & Control Eng.Saga Uni.Japan

In this study, a transonic flow past NACA0012 profile at angle of attack α=0^0 whose aspect ratio AR is 1.0 with non-equilibrium condensation is analyzed by numerical analysis using a TVD scheme and is investigated using an intermittent indraft type supersonic wind tunnel. Transonic flows of 0.78-0.90 in free stream Mach number with the variations of the stagnation relative humidity（φ0） are tested. For the same free stream Mach number, the increase in φ0 causes decrease in the drag coefficient of profile which is composed of the drag components of form, viscous and wave. In the case of the same Moo and To, for more than φ0=30%, despite the irreversibility of process in non-equilibrium condensation, the drag by shock wave decreases considerably with the increase of φ0. on the other hand, it shows that the effect of condensation on the drag coefficients of form and viscous is negligible. As an example, the decreasing rate in the drag coefficient of profile caused by the influence of non-equilibrium condensation for the case of M∞=0.9 and φ0 =50% amounts to 34%. Also, it were turned out that the size of supersonic bubble （that is, the maximum height of supersonic zone） and the deviation of pressure coefficient from the value for M=1 decrease with the increase of φ0 for the same M∞.

关键词： Non-equilibrium condensation Transonic Moist air Drag coefficient Pressure coefficient

MoDELING　oF　SUPERPLASTIC　FoRMING　PRoCESS　FoR　ALUMINUM　ALLoyS　WITH　STRAIN　HARDENING　EFFECT

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Acta Metallurgica Sinica(English Letters) 1996年第6期9卷 537-544页

作者： y.N. kwon and y.-W. Chang(Center for Advanced Aerospace Materials (CAAM), Pohang University of Science and Technology, Pohang 790-784. Korea ) Pohang Univ of Science and Technology Pohang South Korea

Superplastic forming of a thin sheet into complex shape is an important manufacturing process especially in aerospace industry. The main objective of modeling the superplastic forming process is to predict the forming pressure-time cycle to maintain the optimum strain rate and the resulting thickness distribution. There have been many attempts to model superplastic forming process using the various techniques including finite element method. However, most of these attempts so far have disregarded the strain hardening effect which occurs in several superplastic materials. In this study,we have used ABAQUS finite element code to predict the suitable processing variables during an axisymmetric cup forming of Supral 100 and 7075Al alloys to examine the strain hardening effects on forming. The performance of numerical results was then compared with the experimental results.

关键词： superplastic forming strain hardening supral 100 7075Al FEM

PRoDUCTIoN AND DECAy oF b-FLAVoRED HADRoNS

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Chinese Physics C 2016年第10期40卷 746-758页

作者： P. Eerola M. Kreps y. kwon U. of Helsinki Helsinki Finland U. of Warwick Coventry UK yonsei U. Seoul Korea

The b quark belongs to the third generation of quarks and is the weak-doublet partner of the t quark. The existence of the third-generation quark doublet was proposed in 1973 by Kobayashi and Maskawa [1] in their model of the quark mixing matrix （＂CKM＂ matrix）, and confirmed four years later by the first observation of a bb meson [2]. In the KM model, CP violation is explained within the Standard Model （SM） by an irreducible phase of the 3 × 3 unitary matrix. The regular pattern of the three lepton and quark families is one of the most intriguing puzzles in particle physics. The existence of families gives rise to many of the free parameters in the SM, including the fermion masses, and the elements of the CKM matrix.

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Enumerating Abelian Typical Cube-Free Fold Coverings of a Circulant Graph

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Algebra Colloquium 2020年第1期27卷 137-148页

作者： young Soo kwon Jaeun Lee Department of Mathematics Yeungnam UniversityKyongsan712-749Korea

Enumerating the isomorphism or equivalence classes of several types of graph coverings is one of the central research topics in enumerative topological graph theory.A covering projection p from a Cayley graph Cay(Г,X)onto another Cayley graph Cay(Q,y)is called typical if the function p:Г→Q on the vertex sets is a group epimorphism.A typical covering is called abelian(or circulant,respectively)if its covering graph is a Cayley graph on an abelism(or a cyclic,respectively)***,the equivalence classes of connected abelian typical prime-fold coverings of a circulant graph are *** a continuation of this work,we enumerate the equivalence classes of connected abelian typical cube-free fold coverings of a circulant graph.

关键词： graph covering enumeration voltage assignment circulant graph

Effects of a dynamic membrane formed with polyethylene glycol on the ultrafiltration of natural organic matter

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Frontiers of Environmental Science & Engineering 2010年第2期4卷 172-182页

作者： Boksoon kwon Noeon PARK Jaeweon CHo Woongjin R&D Center San 4-1Nakseongdae-dongGwanak-guSeoul 151-057Korea Korea Institute of S&T Evaluation and Planning Yangjae-dongSeocho-guSeoul 137-130Korea Department of Environmental Science and Engineering GIST1 Oryong-dongBuk-guGwangju 500-712Korea

The formation of a dynamic membrane(DM)was investigated using polyethylene glycol(PEG)(molecular weight of 35000 g/mol,concentration of 1 g/L).Two natural organic matters(NoM),Dongbok Lake NoM(DLNoM)and Suwannee River NoM(SRNoM)were used in the ultrafiltration experiments along with *** evaluate the effects of the DM with PEG on ultrafiltration,various transport experiments were conducted,and the analyses of the NoM in the membrane feed and permeate were performed using high performance size exclusion chromatography,and the effective pore size distribution(effective PSD)and effective molecular weight cut off(effective MWCo)were *** advantages of DM formed with PEG can be summarized as follows:(1)PEG interferes with NoM transmission through the ultrafiltration membrane pores by increasing the retention coefficient of NoM in UF membranes,and(2)low removal of NoM by the DM is affected by external factors,such as pressure increases during UF membrane filtration,which decreases the effective PSD and effective MWCo of UF ***,a disadvantage of the DM with PEG was severe flux decline;thus,one must be mindful of both the positive and negative influences of the DM when optimizing the UF performance of the membrane.

关键词： dynamic membrane natural organic matters ultrafiltration membrane performance effective PSD effective molecular weight cutoff

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Introduction

Introduction

4-1BB signaling activates glucose and fatty acid metabolism to enhance CD8^(+) T cell proliferation

Photonics Asia 2004;Sensors and Imaging

作者： osuk y.kwon

These proceedings contain the papers presented at the Photonics Asia 2004 Advanced Sensors Systems and Applications conference, held 8-12 November 2004, in Beijing, China. This conference covered a number of key issues concerning recent progress in advanced sensors and their applications, in particular optical fiber sensors. After more than 20 years, worldwide research and development in the field of optical fiber sensors is still very active. This conference had many more papers submitted than that held two years ago. This strong growth may be due to significant reductions in the cost of most fiber optic components and the maturity of optical fiber sensors, such as fiber grating sensors and interferometric sensors.

关键词： Introduction

来源： cnki会议评论

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Cellular & Molecular Immunology 2017年第9期14卷 748-757页

作者： Beom K Choi Do y Lee Don G Lee young H Kim Seon-Hee Kim Ho S oh Chungyong Han Byoung S kwon Cancer Immunology Branch Division of Cancer BiologyNational Cancer CenterGoyangGyeonggi 10408Korea Department of Internal Medicine Yonsei University College of MedicineSeoul 120-752Korea Immune Cell Production Unit Program for Immunotherapeutic ResearchNational Cancer CenterGyeonggi 10408Korea Eutilex Catholic University School of MedicineSeoul 06591Korea Department of Medicine Tulane University Health Sciences CenterNew OrleansLA 70112USA

4-1BB(CD137)is a strong enhancer of the proliferation of CD8^(+)T *** these cells require increased production of energy and biomass to support their proliferation,we hypothesized that 4-1BB signaling activated glucose and fatty acid *** found that treatment with agonistic anti-4-1BB mAb promoted the proliferation of CD8^(+)T cells in vitro,increasing their size and *** with a glycolysis inhibitor and a fatty acid oxidation inhibitor revealed that CD8^(+)T cell proliferation required both glucose and fatty acid ***-4-1BB treatment increased glucose transporter 1 expression and activated the liver kinase B1(LKB1)-AMP-activated protein kinase(AMPK)-acetyl-CoA carboxylase(ACC)signaling pathway,which may be responsible for activating the metabolism of glucose and fatty *** also examined whether blocking glucose or fatty acid metabolism affected cell cycle progression and the anti-apoptotic effect of 4-1BB *** increase of anti-apoptotic factors and cyclins in response to anti-4-1BB treatment was completely prevented by treating CD8^(+)T cells with the fatty acid oxidation inhibitor,etomoxir,but not with the glycolysis inhibitor,*** conclude that anti-4-1BB treatment activates glucose and fatty acid metabolism thus supporting the increased demand for energy and biomass,and that fatty acid metabolism plays a crucial role in enhancing the cell cycle progression of anti-CD3-activated CD8^(+)T cells in vitro and the anti-apoptotic effects of 4-1BB signaling on these cells.

关键词： AMPK CD8^(+)T cells 4-1BB(CD137) LKB1 metabolism

Controlled multilevel switching and artificial synapse characteristics in transparent HfAlo-alloy based memristor with embedded TaN nanoparticles

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Journal of Materials Science & Technology 2021年第36期95卷 203-212页

作者： Chandreswar Mahata Hassan Algadi Muhammad Ismail Daewoong kwon Sungjun Kim Division of Electronics and Electrical Engineering Dongguk UniversitySeoul 04620Republic of Korea Department of Electrical Engineering Faculty of EngineeringNajran UniversityP.O.Box 1988Najran 11001Saudi Arabia Department of Electrical Engineering Inha UniversityIncheonRepublic of Korea

Atomic layer deposition technique has been used to prepare tantalum nitride nanoparticles(TaN-NPs)and sandwiched between Al-doped Hfo;layers to achieve ITo/HfAlo/TaN-NP/HfAlo/ITo RRAM *** electron microscopy along with energy dispersive spectroscopy confirms the presence of TaN-NPs.X-ray photoelectron spectroscopy suggests that part of Ta N converted to tantalum oxynitride(Tao_(x)N_(y))which plays an important role in stable cycle-to-cycle resistive *** trapping and oxygen vacancy creation were found to be modified after the inclusion of Ta N-NPs inside RRAM ***,HfAlo/Tao_(x)N_(y)interface due to the presence TaN-NPs improves the device-to-device switching reliability by reducing the probability of random rupture/formation of conductive filaments(CFs).DC endurance of more than 10^(3)cycles and memory data retention up to 10^(4)s was achieved with an insignificant variation of different resistance *** conductance was attained by controlling RESET voltage with stable data retention in multiple *** volatile threshold switching was monitored after controlling the CF forming at 200 nA current compliance with high selectivity of~10^(3).Synaptic learning behavior has been demonstrated by spike-rate-dependent plasticity(SRDP).Reliable potentiation and depression processes were observed after the application of suitable negative and positive pulses which shows the capability of the TaN–NPs based RRAM device for transparent synaptic devices.

关键词： RRAM ALD TaN-nanoparticles Threshold switching Spike-rate-dependent plasticity Multilevel conductance Synaptic properties

Scratch formation and its mechanism in chemical mechanical planarization (CMP)

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Friction 2013年第4期1卷 279-305页

作者： Tae-young kwon Manivannan RAMACHANDRAN Jin-Goo PARK Department of Materials Engineering Hanyang UniversityAnsan 426-791Korea

Chemical mechanical planarization(CMP)has become one of the most critical processes in semiconductor device fabrication to achieve global *** achieve an efficient global planarization for device node dimensions of less than 32 nm,a comprehensive understanding of the physical,chemical,and tribo-mechanical/chemical action at the interface between the pad and wafer in the presence of a slurry medium is *** the CMP process,some issues such as film delamination,scratching,dishing,erosion,and corrosion can generate defects which can adversely affect the yield and *** this article,an overview of material removal mechanism of CMP process,investigation of the scratch formation behavior based on polishing process conditions and consumables,scratch formation mechanism and the scratch inspection tools were extensively *** advantages of adopting the filtration unit and the jet spraying of water to reduce the scratch formation have been *** current research trends in the scratch formation,based on modeling perspective were also discussed.

关键词： Chemical mechanical planarization(CMP) defects,scratch post-CMP cleaning defect source