레이저 위빙을 이용한 Al 6k21-T4 합금의 용접 강도 향상

김병훈,강남현,박용호,안영남,김철희,김정한,Kim, Byung-Hun,Kang, Nam-Hyun,Park, Yong-Ho,Ahn, Young-Nam,Kim, Cheol-Hee,Kim, Jung-Han 대한용접접합학회 2009 대한용접·접합학회지 Vol.27 No.4

For Al 6k21-T4 alloy, linear laser welding produced the lower shear-tensile strength than the base metal. This study improved the shear-tensile strength by using the weaving laser at the optimized welding condition, i.e., 2mm weaving width and 25Hz frequency. The large weaving width increased the weld width, therefore improving the joint strength. For the specimen of low strength, the porosity was distributed continuously along the intersection between the plates and fusion line. However, for the optimized welding condition, large oval-shaped porosities were located only in the advancing track of the concave part. Regardless of the welding condition, solidification cracking was initiated at the intersection and propagated through small porosities in the weld part. furthermore, the concave part had more significant porosity in the weld and HAZ, respectively than the convex part. The continuity of porosities played a key role to determine the strength. And, the weaving width was an important parameter to control the strength.

활성화된 단핵구 및 대식세포의 항원제시기능에 대한 Kaempferitrin의 조절 효과

김병훈,조동하,조재열,Kim, Byung-Hun,Cho, Dong-Ha,Cho, Jae-Youl 대한약학회 2007 약학회지 Vol.51 No.6

Kaempferitrin, isolated from Kenaf (Hibiscus cannabinus), was examined to evaluate its modulatory effects on antigen-presenting cell functions of macrophages/monocytes such as phagocytosis of foreign materials, up-regulation of costimulatory molecules (CD40, CD80 and CD86), adhesion molecule activation, and antigen processing and presentation. Kaempferitrin strongly blocked up-regulation of CD40, CD80 and CD86, but not pattern recognition receptor (PRR) (e.g., TLR2). It also suppressed functional activation of CD29 (${\beta}1$-integrins), as assessed by cell-cell adhesion assay, required for T cell-antigen-presenting cell (APC) interaction. Furthermore, this compound did not block a simple activation of CD29, as assessed by cell-fibronectin adhesion assay. However, the compound did not diminish phagocytic uptake, an initial step for antigen processing, and ROS generation in RAW264.7 cells. In particular, to understand molecular mechanism of kaempferitrin-mediated inhibition, the regulatory role of LPS-induced signaling events was examined using immunoblotting analysis. Interestingly, this compound dose dependently suppressed the phosphorylation of $I{\kappa}B{\alpha}$, Src, Akt and Syk, demonstrating that it can negatively modulate the activation of these signaling enzymes. Therefore, our data suggested that kaempferitrin may be involved in regulating APC function-relevant immune responses of macrophages and monocytes by regulating intracellular signaling.

BAY11-7082에 의한 U937 세포의 CD29-매개성 세포간 유착과정 조절 효과

김병훈,조재열,Kim, Byung-Hun,Cho, Jae-Youl 대한약학회 2008 약학회지 Vol.52 No.5

BAY11-7082 was initially found to be an anti-inflammatory drug with NF-${\kappa}B$ inhibitory property. In this study, we evaluated modulatory function of BAY11-7082 on U937 cell-cell adhesion induced by CD29 (${\beta}1$-integrins). BAY11-7082 strongly blocked functional activation of CD29 (${\beta}1$-integrins), as assessed by cell-cell adhesion assay. However, this compound did not block a simple activation of CD29, as assessed by cell-fibronectin adhesion assay. In particular, to understand molecular mechanism of BAY11-7082-mediated inhibition, the regulatory roles of CD29-induced actin cytoskeleton rearrangement under cell-cell adhesion and surface level of CD29 were examined using confocal and flow cytometic analysis. Interestingly, this compound strongly suppressed the molecular association of actin cytoskeleton with CD29 at cell-cell adhesion site. Moreover, BAY11-7082 also diminished surface levels of CD29 as well as its-associated adhesion molecule CD147, but not other adhesion molecules such as CD18 and CD43. Therefore, our data suggest that BAY11-7082 may be involved in regulating immune responses managed by CD29-mediated cell-cell adhesion.

CD29 및 CD98 활성 매개에 의한 Jurkat T 세포의 유착과 그 활용

김병훈,조재열,Kim, Byung-Hun,Cho, Jae-Youl 대한약학회 2009 약학회지 Vol.53 No.3

Cell-cell adhesion managed by various adhesion molecules plays an important role in regulating functional activation of cells. This event mediates attachment of inflammatory cells to endothelial cells, interaction of antigen-presenting cells with T cells and metastatic adherence of cancer cells to epithelial tissue cells. Therefore, this cellular response is considered as one of therapeutic target to treat various cancers and inflammatory diseases. To develop proper model for evaluation of functional activation of adhesion molecules, the ability of U937 and Jurkat T cells responsive to various adhesion inducers such as phorbal-12-myristate-13-acetate (PMA), staurosporin and monoclonal antibodies to CD29, CD43 and CD98 was investigated using quantitative cell-cell adhesion assay. U937 cells made more cell-cell clusters by the treatment of antibodies to CD29 and CD43 than Jurkat T cells, while Jurkat T cells exhibited increased cell-cell adhesion ability in CD98 antibody treatment. In agreement, the surface levels of CD29 and CD98 were highly observed in U937 and Jurkat T cells, respectively. Therefore, our data suggest that Jurkat T and U937 cells can be used for model system to evaluate functional activation of adhesion molecules such as CD29 and CD98.

Diethylstilbestrol의 단핵구의 세포간 유착과정 조절효과

김병훈,조재열,Kim, Byung-Hun,Cho, Jae-Youl 대한약학회 2008 약학회지 Vol.52 No.2

Diethylstilbestrol (DESB) is a synthetic estrogen not only that routinely prescribed, but also that known to be a teratogen. In this study, we found a novel pharmacological feature that DESB is able to positively modulate CD29 $({\beta}1-integrin)$ function. Thus, DESB up-regulated homotypic cell-cell adhesion of monocytic U937 cells mediated by CD29. However, DESB did not increase the surface level of CD29 and its binding activity to ligand (fibronectin), according to flow cytometric analysis and cell-fibronectin adhesion assay. Instead, the DESB-mediated up-regulation of cell-cell adhesion was blocked by several signaling enzyme inhibitors. Treatment of U0126 [an extracellular signal-regulated kinase (ERK) inhibitor], SB20358 (a p38 inhibitor) or Rp-8-pCPT-cGMP (a protein kinase G inhibitor) clearly inhibited DESB-mediated up-regulation of cell-cell adhesion induced by CD29. However, estrogen receptor antagonist ICI 182,780 failed to abrogate DESB effect. Therefore, our data suggest that DESB may up-regulate CD29-mediated cell-cell adhesion via modulating intracellular signaling enzymes such as ERK, PKG, and p38, independent of estrogen receptor function.

단핵구 기능 수행에서의 $CD29({\beta}1-integrins)$ 조절 역할

김병훈,조재열,Kim, Byung-Hun,Cho, Jae-Youl 대한약학회 2008 약학회지 Vol.52 No.1

CD29 $({\beta}1-integrins)$ is one of major adhesion molecules involved in regulating cell adhesion, migration and morphological changes. In this study, we investigated the regulatory role of CD29 in monocytic functions using monocytic cell line U937 cells. CD29 was found to be one of highly expressed membrane proteins in U937 cells, according to flow cytometric analysis. The activation of CD29 by agonistic antibody MEM101A and extracellular matrix protein (ECM) fibronectin strongly induced cell-cell and cell-fibronectin adhesions. However, blocking antibodies to CD98 and CD147 showed different inhibitory features in these two adhesion events. Furthermore, U0126, an ERK inhibitor, only blocked cell-cell adhesion but not cell-fibronectin adhesion, indicating that cell-cell or cell-fibronectin adhesion events may be regulated by different molecular mechanisms. Meanwhile, CD29 activation also enhanced ROS generation but not phagocytic ability, and similarly radical scavenger N-acetyl-L-cysteine strongly blocked CD29-mediated cell-cell adhesion, implying that ROS may play a critical role in up-regulating cell-cell adhesion. Therefore, our data suggest that the activation of CD29 may be critically involved in regulating monocytic cell-mediated cell-cell adhesion and ROS generation.

한국형발사체 추진제 탱크 가압제어용 극저온 솔레노이드밸브 개발 시험

김병훈(Byung Hun Kim),고현석(HyeonSeok Koh),한상엽(SangYeop Han) 한국추진공학회 2012 한국추진공학회 학술대회논문집 Vol.2012 No.11

한국형발사체 추진제 탱크 가압제어 시스템에 사용되는 극저온 솔레노이드밸브의 개발을 진행하고 있다. 한국형발사체에서 극저온 솔레노이드밸브는 가압제 탱크에 극저온 고압 상태로 저장되어 있는 헬륨 가스를 추진제 탱크로 공급/차단하기 위해 사용한다. 극저온 솔레노이드밸브를 개발하기 위해 시제품을 제작하였으며, 제작된 시제품 솔레노이드밸브를 이용하여 성능 시험을 수행하고 있다. 본 연구는 한국형발사체에 사용되는 극저온 솔레노이드밸브에 대한 개발 시험 결과를 정리하였다. The cryogenic solenoid valve has been developed for propellant tank pressurization system of the KSLV-II. In the KSLV-II, cryogenic solenoid valve is employed to control the flow of gaseous helium which is stored at propellant tank as cryogenic and hight pressure state. The DM(development model) of solenoid valve was manufactured and its performance tests have been carried out. This paper summarized the performance test results of cryogenic solenoid valve for propellant tank pressurization system of KSLV-II.

한국형발사체 공압밸브 구동용 솔레노이드 밸브 성능시험

김병훈(Byung Hun Kim) 한국추진공학회 2019 한국추진공학회 학술대회논문집 Vol.2019 No.11

액체로켓시스템은 지상 운용 및 발사 과정에서 추진제 또는 각종 가스의 공급 배출을 위해 많은 공압밸브를 사용한다. 공압밸브는 밸브 구동부에 헬륨 가스를 공급 또는 배출함으로써 밸브를 작동한다. 밸브 구동부에 헬륨가스를 공급 배출하기 위해 3방향 솔레노이드 밸브를 개발하였다. 시험 결과 솔레노이드 밸브는 성능 요구조건을 만족함을 보여준다. The liquid propellant rocket system uses a lot of pneumatic valves for controling fluid flow during ground operation and launch process. The pneumatic valve is operated by suppling/draining helium gas to the valve actuating part. The 3way solenoid valve is developed for on/off control of pneumatic valve. We have performed various performance tests on 3way solenoid valve. Test results showed that the solenoid valve meets the performance requirements.

Transcriptome profiling of Escherichia coli metJ mutant

Byung Hun Kim(김병훈),Sang Jung Lee(이상준),Sang Yup Lee(이상엽) 한국생물공학회 2004 한국생물공학회 학술대회 Vol.2004 No.4

고무 인젝션 방법을 이용한 플렉시블 씰 제작

김병훈(Byung-Hun Kim),권태훈(Tae-hoon Kwon),조인현(In-Hyun Cho) 한국추진공학회 2010 한국추진공학회 학술대회논문집 Vol.2010 No.11

KSLV-Ⅰ 킥모터 노즐 개발에 있어서 가장 중요한 개발품은 노즐 구동에 필요한 플렉시블 씰 개발이다. 특히 플렉시블 씰 제작 기술의 확보는 킥 모터 노즐 개발에 있어서 핵심 개발 사항 중에 하나였다. 킥모터 플렉시블 씰 제작에 사용된 방법은 금형에 순서대로 배열된 보강재 사이에 고무를 주입하는 인젝션 방식을 사용하였다. 플렉시블 씰 제작을 통해 금형 설계 기술, 고무 인젝션 방법, 성형 공정을 확립하였다. 제작된 플렉시블 씰은 X-Ray 검사를 통해 내부 접착 상태 및 보강재/고무 배열 상태를 확인하였다. The most important things in the KSLV-Ⅰ Kick Motor nozzle is a development of flexible seal that is utilized to drive a movable nozzle. Especially, a manufacturing technology of flexible seal is one of the key element in the Kick Motor nozzle development. The method used to produce flexible seal in the Kick Motor is injection method. Mold design technology, rubber injection technic and molding process through flexible seal manufacture has been established. After manufacturing, X-Ray inspection have been carried out to confirm a adhesive and internal array of flexible seal.