• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.6
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• pp.857-866
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• 2013

This paper is concerned with the material properties of functional high explosive(FHX) simulant at various strain rates ranging from $10^{-4}/sec$ to $10^1/sec$. Material properties of FHX at high strain rates are important in prediction of deformation modes of FHX in a warhead which undergoes dynamic loading. Inert FHX stimulant which has analogous mechanical properties with FHX was utilized for material tests due to safety issues. Uniaxial tensile tests at quasi-static strain rates ranging from $10^{-4}/sec$ to $10^{-2}/sec$ and intermediate strain rates ranging from $10^{-1}/sec$ to $10^1/sec$ were conducted with JANNAF specimen using a tensile testing machine, INTRON 5583, and developed high speed material testing machine, respectively. Uniaxial compressive tests at quasi-static strain rates and intermediate strain rates were conducted with cylindrical specimen using a dynamic materials testing machine, INSTRON 8801. And cyclic compressive loading tests were performed with various strain rates and strains. Deformation behaviors were investigated using captured images obtained from a high-speed camera.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.2
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• pp.345-349
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• 2019

The National Aeronautics and Space Administration (NASA) has long been studying the essential elements of manned planetary exploration and has held several international challenges to encourage the research works related to it. One of them was the NASA Centennial Challenge Programs which started in 2015. Following the second in 2017, the third is currently going on in 2019. Participating "3D-Printed Habitat Challenge", one of the challenges in the second program, this research team designed and developed the 3D printer extruding module for the Lunar Simulant (Korea Hanyang Lunar Simulant-1; KOHLS-1) and the polymer. For optimizing the modul, a cylindrical specimen of ${\varnothing}150{\times}300mm^3$ volume and a specimen of $200{\times}100{\times}650mm^3$ volume were manufactured and their compressive and flexural strengths were tested. The findings can help automatize the space construction in the future.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.1
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• pp.15-21
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• 2022

The purpose of our study was to investigate the migration level of lead (Pb), cadmium (Cd), and barium (Ba) from glassware into a food simulant and to evaluate the exposure of each element. The test articles were glassware, including tableware, pots, and other containers. Pb, Cd, and Ba were analysed by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The analytical performance of the method was validated in terms of its linearity, limit of detection (LOD), limit of quantification (LOQ), recovery, precision, and uncertainty. The monitoring was performed for 110 samples such as glass cups, containers, pots, and bottles. a food simulant. Migration test was conducted at 25? for 24 hours in a dark place using 4% acetic acid as a food simulant. Based on the data; exposure assessment was carried out to compare the estimated daily intake (EDI) to the human safety criteria. The risk levels of Pb and Ba determined in this study were approximately 1.9% and 0.3% of the provisional tolerable weekly intake (PTWI) and tolerable daily intake (TDI) value, respectively, thereby indicating a low exposure to the population.

• Proceedings of the Korean Nuclear Society Conference
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• 2003.05a
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• pp.191.1-191.1
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• 2003

• Nuclear Engineering and Technology
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• v.52 no.9
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• pp.1963-1973
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• 2020

Liquid metal-cooled reactors use various passive safety systems driven by natural circulation. Investigating these safety systems experimentally is more advantageous by using a simulant. Although numerous experimental approaches have been applied to natural circulation-driven passive safety systems using simulants, there has been no clear validation of the similarity law. To validate the similarity law experimentally, SINCRO-V experiment was conducted using Wood's metal and water for simulant of the Wood's metal. A pair of SINCRO-V facilities with length-scale ratio of 14.1:1 for identical Bo' was investigated, which was the main similarity parameter in temperature field simulation. In the experimental range of 0.2-1.0% of decay heat, the temperature distribution characteristics of the small water facility were very similar to that of the large Wood's metal facility. The temperature of the Wood's metal predicted by the water experiment showed good agreement with the actual Wood's metal temperature. Despite some error factors like discordance of Gr' and property change along the temperature, the water experiment predicted the Wood's metal temperature with an error of 27%. The validity of the similarity law was confirmed by the SINCRO-V experiments.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.11
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• pp.1447-1456
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• 2000

Simulated experiments of high pressure melt ejection(HPME) are performed to measure the released fraction of corium simulant from the French type PWR cavity. The experiments are carried out on a 1/20th linear scaled model of the Ulchin 1&2 cavity. Water or woods metal and nitrogen is used as simulant of molten corium and steam, respectively. Experimental parameters are water mass, annulus area and breach size. It is shown that only breach size effects is very important while the mass and the annulus area do not affect the released fraction. It is found that the liquid film transport is much more dominant mechanism than the entrainment droplet transport, especially in linear scale down simulated HPME experiment.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.3
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• pp.1-8
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• 1999

Mixing efficiency of the unlike Impinging split triplet injector(FOOF type) were measured to investigate the effect of the momentum ratio variation. $H_2$O/kerosene were used as a propellant simulant. The maximum mixing efficiency occured at the momentum ratio 1.5 (total mixture ratio 1.89). Calculated mixing efficiency of real propellant LOX/Kerosene showed similar trend but maximum efficiency of characteristic velocity occurs at the momentum ratio 2.0(total mixture ratio 2.17). Although there exist a little discrepancy between calculated mixing efficiency based on simulant cold test and hot fire test results, this calculated mixing efficiency can be used to predict hot fire mixing efficiency.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.10
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• pp.1257-1262
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• 2014

The variances of atomization characteristics with the misalignment of injectors defined as the fraction of skewness for various angles of impingement and pressure conditions were studied using the doublet impinging injectors with a like-on-like arrangement. Water was used as simulant and the spray characteristics along with the changes in the skewness were analyzed using the methods of spray image photography. Experiment was carried for the impinging nozzles of orifice diameter of 1.2 mm within Reynolds numbers ranging from $9{\times}10^3-4.5{\times}10^4$ and the fraction of skewness considered for the experiment ranges from 0.0 to 0.9 at ambient temperature condition. Flat sheet with a distinct rim produced perpendicular to the plane of impinging jets goes ondisappear and sheet appears comparatively shorterwith the increase in fraction of skewness resulting the atomization of fluid droplet very close to impingement point with decrease in breakup length and increase in spray angle up to certain extent. The maximum allowable skewness was found as the result. The skewness up to the certain extent can be considered as the parameter to control the atomization characteristics of simulant inside the combustion chamberproviding the high economic performance of fuel and time.

• Textile Coloration and Finishing
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• v.32 no.1
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• pp.51-56
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• 2020

This study aims to pursue the multi-functional textile finishing method to detoxify chemical warfare agent by simply treating the well-known antimicrobial agent, chitosan, to cotton fabric. For this purpose, DFP(diisopropylfluorophosphate) was sele cted as a chemical warfare agent simulant and cotton fabric was treated with 0.5, 1.0, and 2wt% chitosan solution in 1wt% acetic acid. DFP decontamination properties of the chitosan treated cotton fabrics were evaluated and compared with the untreated cotton fabric. The chitosan treated cotton fabrics showed better DFP decontamination than the untreated cotton. Decontamination properties of the chitosan treated cotton fabrics improved with the increased chitosan solution used. Especially, the cotton fabrics treated with 2wt% chitosan solution showed 5 times more DFP decontamina tion than the untreated cotton fabrics. This suggested that the chitosan treated fabric has potential to be used as a material for protective clothing with chemical warfare agent detoxifying and antimicrobial properties.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.19 no.3
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• pp.339-352
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• 2021

Legacy waste from the decommissioned A-1 nuclear power plant in the Slovak Republic is scheduled for immobilisation within a tailored alkali borosilicate glass formulation, as part of ongoing site cleanup. The aqueous durability and characterisation of a simulant glass wasteform for Chrompik III legacy waste, was investigated, including dissolution experiments up to 112 days (90℃, ASTM Type 1 water). The wasteform was an amorphous, light green glassy product, with no observed phase separation or crystalline inclusions. Aqueous leach testing revealed a suitably durable product over the timescale investigated, comparing positively to other simulant nuclear waste glasses and vitreous products tested under similar conditions. Iron and titanium rich precipitates were observed to form at the surface of monolithic samples during leaching, with the formation of an alkali deficient alteration layer behind these at later ages. Overall this glass appears to perform well, and in line with expectations for this chemistry, although longer-term testing would be required to predict overall durability. This work will contribute to developing confidence in the disposability of vitrified Chrompik legacy wastes.