• YAKHAK HOEJI
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• v.48 no.1
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• pp.82-87
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• 2004

Mungbean trypsin inhibitor (MBTI) was isolated and purified from Mung bean which has been used as a galenic and traditional food. MBTI and poly(ethylene glycol) were conjugated by using water soluble carbodiimide. We evaluated the therapeutic value of the MBTI and MBTI-PEG conjugate using animal models, sublethal septic shock model in guinea pig caused by pseudomonal elastase, shock model in rat caused by lipopolysaccharide, and the vascular permeability test by using pseudomonal elastase. In two shock model in guinea p Is and in rat, hypotesion shock was inhibited by pretreatment of MBTI. And also the vascular permeability caused by pseudomonal elastase reduced by pretreatment of MBTI. Also, therapeutic value of the MBTI-PEG conjugate was evaluated by using the sublethal septic shock model caused by pseudomonal elastase. The MBTI-PEG conjugate was more effective than native MBTI against pseudomonal elastase induced septic shock in guinea pig model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.581-586
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• 2000

Explosively activated pyro-technic device is used to release exhausted rocket booster or payloads at prescribed times in the rocket's flight. It creates pyro-shock environment that rocket or payload components must survive. With the shock spectra acquired from flight data, laboratory test should be performed before flight to check whether all of component can sustain the shock environment. The pyro-shock environment simulation was created by the resonance fixture response to a projectile impact. Desired shock spectra is realized by adjusting the natural frequency of resonance plate and the velocity of impact hammer. This paper describes the development process of Pyro-shock testing machine, which is designed and tested by Korean engineers, to verify components of Korean Sounding Rocket(KSR-3) and the other Korean space vehicle. Both analytical and experimental techniques are introduced in this paper.

• Steel and Composite Structures
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• v.44 no.2
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• pp.211-224
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• 2022

Multi-objective optimization was conducted to obtain the optimal configuration of a composite sandwich structure with honeycomb-foam hybrid core subjected to underwater shock waves, which can fulfill the demand for light weight and energy efficient design of structures against underwater blast. Effects of structural parameters on the dynamic response of the sandwich structures subjected to underwater shock waves were analyzed numerically, from which the correlations of different parameters to the dynamic response were determined. Multi-objective optimization of the structure subjected to underwater shock waves of which the initial pressure is 30 MPa was conducted based on surrogate modelling method and genetic algorithm. Moreover, optimization results of the sandwich structure subjected to underwater shock waves with different initial pressures were compared. The research can guide the optimal design of composite sandwich structures subjected to underwater shock waves.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.44.1-44.1
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• 2020

Hα jets of cool chromospheric plasma are protruding into the solar corona 10-100 Mm above the photosphere. The driving mechanisms of Hα jets have been widely studied for decades. However, the detailed process is still elusive. We observed shock signatures moving along a dark jet using 1.6 meter Goode Solar Telescope at Big Bear Solar Observatory. The first shock front of the jet shows sharp --- when it moves upward, while fuzzy and granulated when it moves downward. The jet itself extends upward when the second shock front of the jet reaches the top of the jet. We find abrupt EUV brightenings when the second shock front collides with the edge of the jet. The third front and the fouth front quasi-periodically. These phenomena might be the signs of the rebound shock waves triggered by p-mode wave leakages at the bottom of the jets. Our observation suggests that the jet can be triggered by the rebound shock waves generated by the p-mode waves leaked at the bottom of the jets.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.36.5-37
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• 2021

Gamma-ray binaries는 밀집성(중성자별과 블랙홀)과 질량이 큰 동반성 (>20 Msun)이 서로 공전하는 시스템이다. 이러한 시스템은 X선 영역에서 공전 주기에 따른 변광을 보이는 특징을 갖고 있는데, 이를 설명하기 위해 intrabinary shock(IBS) 모델을 이용한다. IBS는 두 천체의 항성풍이 상호작용하여 만들어내는 shock인데, 이 shock에서 가속된 입자들이 싱크로트론 기작을 통하여 X선 복사를 한다고 알려져 있다. 복사의 강도는 shock의 기하구조 변화 때문에 밀집성의 공전 위상에 따라서 주기적으로 변하는데, 이를 모형화하여 관측 데이터와 비교함으로써 궤도와 shock의 특성을 알아낼 수 있다. 이 발표에서는 IBS 모델을 설명하고, 이 모델을 매우 복잡한 X선 광도곡선을 보이는 gamma-ray binaries 중 하나인 HESS J0632+057에 적용한다. 그 결과로 이 천체계의 궤도를 추정하고, 동반성 disk와 shock의 상호작용 특성을 파악해보았다.

• Journal of The Korean Astronomical Society
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• v.37 no.5
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• pp.477-482
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• 2004

Shock waves form in the intergalactic space as an ubiquitous consequence of cosmic structure formation. Using N-body/hydrodynamic simulation data of a ACDM universe, we examined the properties of cosmological shock waves including their morphological distribution. Adopting a diffusive shock acceleration model, we then calculated the amount of cosmic ray energy as well as that of gas thermal energy dissipated at the shocks. Finally, the dynamical consequence of those cosmic rays on cluster properties is discussed.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.29-33
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• 2004

The present study was done to evaluate the environmental factors responsible for the expression of Porphyromonas gingivalis heat shock protein. The intensity of the heat shock protein gene expression was comparable to those seen by the heat shock ptreatment of the bacteria $(44^{\circ}C)$ when the bacteria was grown as a mixed culture or biofilm state at $37^{\circ}C$.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.468-474
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• 2003

1. Schedule for the meetings of ISO/TC108 Mechanical vibration and shock and ISO/TC108/SC3 Use and calibration of shock measuring instruments 2. Minutes for the seventh meeting of ISO/TC108/WG23 Mechanical vibration and shock - Resilient mounting systems - Information for the application of source and receiver isolation (omitted)

• Journal of Mechanical Science and Technology
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• v.15 no.11
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• pp.1599-1604
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• 2001

Axisymmetric compressible flow field induced by shock diffraction from a finite cone is investigated with experimental and computational methods. Double-exposure holographic interferograms show ima ges of the density field integrated along the light path. Using the sight-integrated density based on the Able transformation, the axisymmetric computational results are compared qualitatively with the experiment. In the present paper, we observed some distinguishing flow physics: the fault structure of vortex ring, the shock-vortex interaction, and the morphological transformation of shock waves.

• 한국연소학회:학술대회논문집
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• 2015.12a
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• pp.223-226
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• 2015

A pyrotechnic system that consists of donor/acceptor pair separated by a gap relies on shock attenuation characteristics of the gap material and shock sensitivity of the donor and acceptor charges. We apply a level-set based multimaterial hydrocode with reactive flow models for pentolite donor and heavily aluminized RDX as acceptor charge. The complex shock interaction, critical gap thickness, acoustic impedance, and go/no-go characteristics of the pyrotechnic system are quantitatively investigated.