• 대한예방의학회:학술대회논문집
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• 2004.10a
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• pp.28.2-29
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• 2004

• 대한예방의학회:학술대회논문집
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• 2004.10a
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• pp.28.1-28.1
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• 2004

• 대한예방의학회:학술대회논문집
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• 2004.10a
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• pp.29.1-29.1
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• 2004

• 대한예방의학회:학술대회논문집
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• 2004.10a
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• pp.29.2-30
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• 2004

• International Journal of Highway Engineering
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• v.11 no.3
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• pp.33-40
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• 2009

The use of the crumb rubber as an asphalt binder modifier may contribute to road maintenance and repair. The adhesion properties of the crumb rubber modified asphalt (CRMA) sealant have attracted interest due to brittle and adhesion failure of asphalt binders at low temperatures. In this study, the influence of a flexibilizer as a modifier for CRMA at low temperatures was investigated. Their properties were measured using the penetration, the softening point, the tensile and tensile adhesion tests at low temperature. The tensile adhesion strength and the strain of CRMAs were increased with increasing ductile deformation of the CR and the asphalt binder in the flexiblizer modified CRMAs. It was found that the flexibilizer concentration was an important factor for tensile and adhesion properties of CRMAs at low temperatures.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.2
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• pp.46-53
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• 2005

We have analyzed the temperature and humidity aging test results of a composite solid propellant. The temperature aging test was performed to evaluate the storage life of a propellant, while the humidity aging test could provide the hygroscopicity of Ammonium Perchlorate(AP) exposed to .elative humidity (RH) 10, 30, $50\%$ environment. A specimen was used in the temperature test, and a block of propellant from the actual motor was used in the humidity test. We report that the 4-month storing at 60 degree is equivalent to the 10-year 60 degree condition. The composite solid propellant with HTPB binder showed signs of hardening with time lapse but the effect of humidity up to RH $50\%$ was not noticeable.

• Perspectives in Nursing Science
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• v.17 no.2
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• pp.72-79
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• 2020

Purpose: This study sought to verify the effectiveness of the Nurse Hand Cream developed to protect the skin of the hands of nurses damaged by frequent hand hygiene. Methods: A randomized controlled trial was conducted that compared the hand skin moisture content of subjects using the Nurse Hand Cream that had been developed for nurses with that of the other hand cream. Results: After applying the hand cream, the subjects' skin moisture content were measured using a skin moisture measuring device; the moisture content of the experimental group significantly increased compared with the control group (p<.001). In particular, as a result of the second experiment that involved the four-time performance of hand hygiene every 30 minutes for two hours, the skin moisture content of the experimental group significantly increased compared with the control group, and 84.4% of the experimental group maintained a normal or higher skin moisture content. Conclusion: The hand cream for nurses was statistically confirmed to strengthen the moisturizing power and prevention of skin moisture loss compared with the other hand cream.

• Journal of Welding and Joining
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• v.9 no.2
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• pp.44-50
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• 1991

The use of high tensile steel plates is increasing in the fabrication of ship and offshore structures. The softening region which has lower yield stress than base metal is located to prevent cracking in the conventional high tensile steel. Also, thermo mechanical control process(TMCP) steel with low carbon equivalent has the softening region which occurs in the heat affected zone when high heat input weld is carried out. The softening region in the high tensile steel gives rise to serious effect on structural strength such as tensile strength, fatigue strength and ultimate strength. In order to make a reliable structural design using high tensile steel plates, the influence of the softening on plate strength should be evaluated in advance. In the previous paper, the authors discussed the ultimate compressive strength of 50HT steel square plates with softening region. In this paper, the ultimate compressive strength with varying the yield stress of softening region and the aspect ratio of the plate is investigated by using the elasto-plastic large deformation finite element method.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.149-154
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• 2003

Changes in mineral (Ca, Mg) contents and pectic substances of mature-green 'Nanko' Mume fruits hermetically packaged in 0.03 mm low density polyethylene (LDPE) films with and without gas absorbents were examined during storage at $25^{\circ}C$ for 10 days. Each packaging contained 10 g $Ca(OH)_2$ as a carbon dioxide scavenger, 30 g $KMnO_4$ as an ethylene scrubber or their mixture. In the presence of the ethylene scrubber, losses in mineral contents of alcohol insoluble solids and water soluble pectin were remarkably suppressed, whereas no significant difference was observed in the Ca content between the fresh fruit and those stored for 10 days. Fruits packaged with the ethylene absorbent retained higher amount of pectic substances than those with other packaging treatments. Degradation of the pectic substances into small molecules was also noticeably reduced when the ethylene scrubber was used. Overall results showed that the combination of the gas permeable film and the ethylene absorbent could be applied to mature-green Mume fruits as an effective packaging method to retard the texture softening during storage at the ambient temperature.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.675-680
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• 2008

The physical quality and microbial safety of Korean beef jerky was evaluated at various steps during its preparation. Microbial counts in raw beef demonstrated mesophillic bacteria at 4.20 Log CFU/g, psychrotrophic bacteria at 3.85 Log CFU/g, anaerobic bacteria at 4.90 Log CFU/g, and yeast and molds at 1.92 Log CFU/g. Spore-forming bacteria and coliforms were not detected in raw beef samples. Spices and spiced meats showed similar trends in microbial counts, demonstrating minimal microbial contamination during these stages of preparation. The final beef jerky product exhibited counts of mesophillic bacteria at 1.15-1.66 Log CFU/g, psychrotrophic bacteria at 1.15-1.66 Log CFU/g, and anaerobic bacteria at 0.81-1.72 Log CFU/g. Spore-forming bacteria, yeast and molds, and coliforms were not detected in beef jerky. Significant differences from added ingredients occurred for instron textural profile analysis traits for hardness. In general, Korean beef jerky with humectant and tenderizer had lower hardness than control (without humectant and tenderizer). Also, the sample added with 0.01% protease from Streptomyces griseus had lower hardness than all samples. All samples had 0.7l to 0.72 water activities, and the color and pH were not shown in significant changes of all samples.