• 한국안전학회지
• /
• 제27권2호
• /
• pp.20-24
• /
• 2012

Experimental studies were performed to investigate the eye injury risks by different BB pellet materials. Four different BB pellet materials were used: plastic (P), silicon (S), rubber (R) and plastic covered with silicon (SR). The BB pellet images penetrating into the gelatine simulant were recorded by a high-speed video camera. The results obtained from the different pellet materials were discussed in terms of impact velocity and penetration depth; threshold velocity and projectile sectional density; eye injury risks by normalized energies. It was found that the P pellets caused higher impact velocity while the lower was SR pellets. The penetration depth and threshold velocity of the pellets were dependent on the impact velocity of the pellets, and the P pellets resulted in the higher eye injury risk while the lower was SP.

• 한국식품영양과학회지
• /
• 제33권2호
• /
• pp.447-450
• /
• 2004

목재에 코팅재로 사용되는 에폭시 수지로부터의 총괄이행량에 대한 모델을 정립하고, 이를 이용하여 안전성확보에 필요한 두께의 정도를 계산하였다. 에폭시 수지를 통한 총괄이행은 위생적 관심영역에서 확산모델에 의하여 해석이 가능하였고, 투과성 겉보기 투과성 지표에 미치는 온도의 영향은 Arrhenius 방정식으로 설명이 가능하였다. 그리고 일반적인 식품공전의 6$0^{\circ}C$, 30분의 용출조건에서 위생적 한도를 만족시키기 위한 최소의 코팅두께는 0.004 mm였다.

• 한국염색가공학회지
• /
• 제32권2호
• /
• pp.73-79
• /
• 2020

Pursuing the fabric materials for military chemical warfare protective clothing with the improved detoxification properties, this study investigated the simple and effective cotton treatment method using pad-dry-cure process and 3-aminopropyltrimethox ysilane(APTMS) solution for surface amination. Detoxification properties of the untreated and treated cotton fabrics were evaluated via decontamination of chemical warfare agent simulant, DFP(diisopropylfluorophosphate). The surface aminated cotton fabric increased the rate of the hydrolysis of DFP by the factor of 3 and the decontamination ratio reached 88.2% after 24h. Therefore, the surface amination of the cotton fabric with APTMS can be an effective pathway to prepare the material for protective clothing against chemical warfare agents.

• 한국군사과학기술학회지
• /
• 제5권3호
• /
• pp.105-112
• /
• 2002

A combined process of non-thermal plasma and catalytic techniques has been investigated to treat toxic gas compounds in air. The treated gas in the present study is $CH_3$CN that has been known to be a simulant of toxic chemical agent. A planar type dielectric barrier discharge(DBD) reactor has been used to generate non-thermal plasma that produces various chemically active species, O, N, OH, $O_3$, ion, electrons, etc. Several different types of adsorbents and catalysts, which are MS 5A, MS 13X, Pt/alumina, are packed into the plasma reactor, and have been tested to save power consumption and to treat by-products. Various aspects of the present techniques, which are decomposition efficiencies along with the power consumption, by-product analysis, reaction pathways modified by the adsorbents and catalysts, have been discussed in the present study.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 춘계학술대회
• /
• pp.1578-1583
• /
• 2003

LAVA-ERVC experiments have been performed to investigate the effect of insulation design features on the coolability in case of the external reactor vessel cooling (ERVC). All the 4 tests have been performed using Alumina iron thermite melt as a corium simulant. Due to the limited steam venting through the insulation, steam binding occurred inside the annulus in the KSNP case simulation. On the contrary, in the tests which were performed for simulating the APR1400 insulation design, sufficient water ingression and steam venting through the insulation lead to effective cool down of the vessel characterized by nucleate boiling. It could be found from the experimental results that modification of the insulation design allowing sufficient ventilation could increase the positive effects of the external reactor vessel cooling.

• Journal of Mechanical Science and Technology
• /
• 제14권4호
• /
• pp.466-476
• /
• 2000

This paper presents atomization characteristics of a double impinging F -0-0- F type injector with four streams. A phase Doppler particle analyzer was employed to measure the droplet-size and water was used as the inert simulant liquid instead of reactive propellant liquids. The droplet mean diameter (SMD) and size distribution were measured to investigate the effects of the momentum ratio and pressure drop variations. This experimental results can be used during the preliminary design stage of a impinging stream type injector for liquid rockets.

• 한국안전학회지
• /
• 제13권1호
• /
• pp.13-18
• /
• 1998

It is well known in the fracture mechanics community that the fracture toughness of brittle materials, such as ceramics, can be improved improves significantly when fibers are added into the material. This is because in presence of fibers the cracks cannot propagate as freely as it can in absence of them. Fibers bridge the gap between two adjacent surfaces of the crack and reduce the crack tip opening displacement, thus make it harder to propagate. Several investigators have experimentally studied how the length, diameter and volume fraction of fibers affect the fracture toughness of chopped strand reinforced matrix composite materials. In this paper, matrix used ALS, Arizona Lunar Simulant, types of fiber used carbon steels and stainless steels. To analyze quantitatively fiber reinforced ALS composites, experimental and analytical methods was progressed. Load-displacement curve is used to experimental method, and FEM analysis program using ABAQUS is used analytical method.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2002년도 제25회 KOSCI SYMPOSIUM 논문집
• /
• pp.89-95
• /
• 2002

A hybrid De- NOx technique of non-thermal plasma and $NH_3$ SCR process has been investigated to remove NOx from 300 hp marine engine exhaust under the low temperature conditions, i.e. $100-200^{\circ}C$. Fundamental investigation with Diesel-like simulant gas was also conducted. The performance of the present technique has been demonstrated by treating real diesel exhaust gases, in which high contents of soot, water vapor, $SO_2$, NOx, and unburned HC are included. Detailed engineering data for evaluating the feasibility of the technique are provided in the present investigation.

• 한국분무공학회지
• /
• 제24권2호
• /
• pp.82-88
• /
• 2019

Shear coaxial injectors were commonly used in rocket engine combustor. They showed good combustion performance. However it is not easy to control the thrust. Pintle injectors were not as popular as the coaxial injectors so far, they have a great advantage over the coaxial injectors. That is, it is relatively easy to control the thrust. Spray characteristics of gel type propellant from movable sleeve pintle injector were investigated. Water with 0.05% of Carbopol 940 was used as gel simulant instead of kerosene gel combined with Thixarol ST for academic purpose. Experiments were performed in various temperature, pressure and pintle opening condition. The results were compared with neat liquid spray. It is also verified that the capabilites of the injector by adjusting the pintle opening.

• Nuclear Engineering and Technology
• /
• 제56권2호
• /
• pp.636-643
• /
• 2024

The coolability of the debris bed with a simulant of solidified corium is experimentally studied, focusing on the effects of the structure of the axial stratified debris bed on the dryout heat flux (DHF). DHF was obtained for the four structures with different particle sizes for the axial stratified debris bed under top flooding. The experimental results show that the dryout position of the axial stratified debris bed is formed at the stratified interface indicated by the temperature rise, and the DHF of the axial stratified bed is much lower than that of the homogeneous bed packed with the upper small particles. To predict the dryout heat flux of the stratified debris beds, by considering the properties of the mixed area, a one-dimensional dryout heat flux model of the porous medium is derived from a water and vapor momentum equation for porous medium, two-phase permeability modifications, interfacial drag, and the correlation between capillary pressure and liquid saturation and verified with the experimental data. The modified model can give reasonable results under different structures.