• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.547-550
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• 2008

Precipitation characteristics of the Fe-36Ni based high strength Invar alloy for power transmission wire was investigated in this study. High strength can be obtained in this alloy through precipitation hardening and strain hardening by cold working. $FactSage{(R)}$ in this study, revealing that equilibrium phases which can be formed are two kind of MC-type precipitates and MoC carbide. The latter stoichiometric carbide was expected to be formed at relatively lower temperature $770^{\circ}C$. High strength above 1000MPa and 40% of elongation were obtained at room temperature in both cases.

• Journal of Welding and Joining
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• v.22 no.1
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• pp.43-49
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• 2004

Contact tip is located so near to welding arc that it is heated to high temperature during long time welding. In such a situation, tip changes in its microstructure and in turn its mechanical properties. This study was intended to investigate those changes by using simulated heat treatment. As a result of this study, it was confirmed that tip of Cu-P alloy hardened with severe cold deformation lose its initial hardness to a large extent within 60 min due to the occurrence of rapid recrystallization while that of Cu-Cr composition hardened by proper aging treatment can preserve its intial hardness for about 1,000 min or longer. Based on these results, suggested was a guideline that can classify contact tips into two different grades: deformation-hardened type and precipitation-hardened type. Following a guideline, a tip with Cu-Cr composition can be classified into the deformation-hardened type if it is in the over-aged condition. Such a guideline is well described.

• International Journal of Highway Engineering
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• v.8 no.4 s.30
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• pp.135-143
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• 2006

This study evaluated the fatigue resistance characteristics of hot-mix recycled asphalt mixtures which were prepared by a new blending method. Since the binder of RAP shows higher viscosity without being rejuvenated in the ordinary recycled mixture, this new(modified) blending method was developed for obtaining more uniform level of binder viscosity in the recycled mixture. Cold-planned RAP was collected and mix design was performed using 15% RAP content for two virgin aggregate, gneiss and granite. Penetration grade of 60-80 asphalt was used in mixing recycled mixture together with a polymer modifier, LDPE. Indirect tensile fatigue tests were carried out to evaluate characteristics of fatigue resistance of performance of recycled asphalt mixtures. The recycled mixtures with LDPE 6% showed higher repeated loading fatigue life. Fatigue life ratio of new(N) mixing method mixtures was approximately 0.6-0.7 before aging and 0.8-1.0 after aging treatment of ordinary(O) mixing method mixture. This means the N mixture becomes stronger with aging process increase. If further aging is treated, N mixture may be showing stronger resistance than O mixture.

• Food Science of Animal Resources
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• v.38 no.2
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• pp.251-258
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• 2018

We investigated microbial and quality changes in wrap-packaged dry-aged beef after completion of aging and subsequent storage in a refrigerator. After 28 days of dry aging (temperature, $4^{\circ}C$; RH, approximately 75%; air flow velocity, 2.5 m/s), sirloins were trimmed, wrap-packaged, and stored at $4^{\circ}C$ for 7 days. Analyses of microbial growth, pH, volatile basic nitrogen (VBN), 2-thiobarbituric acid-reactive substance (TABRS), and instrumental color, myoglobin, and sensory evaluation were conducted on days 0, 3, 5, and 7. The results show that the number of total aerobic bacteria (TAB), yeast, and lactic acid bacteria increased with an increase in storage days, whereas no change in the growth of mold was observed during 7 days of storage. Based on the legal standard for TAB count, the estimated shelf-life of wrap-packaged dry-aged beef was predicted to be less than 12.2 days. However, the shelflife should be less than 6.3 days, considering the result of sensory quality (odor, taste, and overall acceptance). No significant change in visible appearance was also observed during 7 days of storage. The results suggest that the present quality indicators for meat spoilage (pH, VBN, and TBARS) should be re-considered for dry-aged beef, as its characteristics are different from those of fresh and/or wet-aged beef.

• Fashion & Textile Research Journal
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• v.11 no.5
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• pp.833-839
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• 2009

This study was to investigate the human's physiological responses and subjective sensations with wear trial through seasonal condition by age. Climate chamber was set $5^{\circ}C$, RH 45% for winter and $30^{\circ}C$, RH 65% for summer condition. Thirty male subjects were volunteered consisted of 10 people in their 20s, 40s, and 60s. In this study physiological responses such as rectal temperature, skin temperature, clothing microclimate, heart rate and blood pressure were measured. As for age, 60s was the highest in rectal temperature regardless of seasonal condition. In skin temperature, 40s was the highest in winter and 20s was the highest in summer. In clothing microclimate temperature and heart rate, 20s was the highest regardless of seasonal condition. And blood pressure was appeared the highest in 20s regardless of seasonal condition. Subjective sensations such as temperature sensation, wetness sensation and thermal comfort were measured. The subjects revealed that temperature sensation was higher 20s than 60s. Compare of other age group, 60s felt colder in the same environment and clothing. It suggested that temperature susceptibility in 60s became weakened showing no change sensation during the cold exposure. Wetness sensation was higher 20s than 60s. Thermal comfort of 60s was felt more discomfortable than any other age group. This means require the supplement of a suitable clothing in order to adjust to change of environmental conditions.

• Korean Journal of Materials Research
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• v.4 no.2
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• pp.241-249
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• 1994

We studied on the effects of hot-worm rolling on recrystalized structures and tensile strength in over-aged 7075 A1 alloy, to develop the process for improving properties. It showed more clear effect of the grain refinement with over-aging before plastic deformation. That means, the coarse precipitates from over-aging play a roll as nucleation sites in the course of recrystallization. And on this study, the relations between yield strength and grain size was not satisfied with Hall-Petch equation because of the elongated structure, but the yield strength is proportional to aspect ratio of grains. In TMT process for improving strength and toughness, the worm working is available for increase of those properties than cold working.

• Journal of the Korean Society of Fashion and Beauty
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• v.2 no.1 s.1
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• pp.5-13
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• 2004

This study was analyzed on relationship of blood vessel pressure massage and skin and management method on blood vessel pressure for skin care with Yin-yang 5 factors theory, Yin-yang 5 factors theory of blood vessel pressure massage with related Korean medicine is essential for descriptions of the physiology of human body and disease. Six elements(wind, heat, fire, dryness, wetness, and cold) and seven emotions(anger, happiness, thought, worry, sadness, surprise, and fear) effected on skin care and the five viscera and the six stomach. Blood vessel pressure massage related with skin consists of the five viscera and the six stomach and is improved blood circulation and is retarded aging of skin by controls of hormone and free nerve system. Blood vessel pressure massage for skin care improved in the intestine system and blood circulation and got healthy. The blood vessel pressure massage treatment of beauty art can aid the function of bio-rhythm of a human body and make our body health by healing the problems of the five viscera organs and the six stomach. It also help circulate of the blood flow and vigor. The study expects the related researches to improve the various treatments through this treatment. The researcher encountered many problems with the lack of concerned materials and former studies but expects this study to be a study to retard aging the skin and prevent the diseases through the study of the blood vessel pressure massage.

• Journal of Ginseng Research
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• v.47 no.4
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• pp.524-533
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• 2023

Background: Obesity is a risk factor for aging and many diseases, and the disorder of lipid metabolism makes it prominent. This study aims to investigate the effect of ginsenoside Rg1 on aging, lipid metabolism and stress resistance Methods: Rg1 was administered to Caenorhabditis elegans (C. elegans) cultured in NGM or GNGM. The lifespan, locomotory activity, lipid accumulation, cold and heat stress resistance and related mRNA expression of the worms were examined. Gene knockout mutants were used to clarify the effect on lipid metabolism of Rg1. GFP-binding mutants were used to observe the changes in protein expression Results: We reported that Rg1 reduced lipid accumulation and improved stress resistance in C. elegans. Rg1 significantly reduced the expression of fatty acid synthesis-related genes and lipid metabolism-related genes in C. elegans. However, Rg1 did not affect the fat storage in fat-5/fat-6 double mutant or nhr-49 mutant. Combined with network pharmacology, we clarified the possible pathways and targets of Rg1 in lipid metabolism. In addition, Rg1-treated C. elegans showed a higher expression of anti-oxidative genes and heat shock proteins, which might contribute to stress resistance Conclusion: Rg1 reduced fat accumulation by regulating lipid metabolism via nhr-49 and enhanced stress resistance by its antioxidant effect in C. elegans.

• Korean journal of food and cookery science
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• v.22 no.3 s.93
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• pp.337-345
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• 2006

The properties of various grains used for the solid-state cultivation of basidiomycetes were examined. The hydration time with cold water was 10 hours for malt soybean. The required hydration time for Job's tears, barley and wheat was 4, 6 and 12 hours, respectively, but the final moisture content ranged from 30 to 48 %, which was much less than the optimum moisture content for mycelial growth. For the mass cultivation of mycelia, the hydrated grains with cold water were placed in plastic bottles. The mycelial growth ra in e bottled grains was high in the early stage with inoculation of homogenized mycelium. The mycelium activity was maintained by adding sterilized water in the middle of the cultivation period. Jupjang underwent sensory evaluation to examine the possibility of utilizing basidiomycetes in functional foods. The grains fermented with Ganoderma lucidum was the best for Jupjang. The combination of malt soybean and Job's tears was the best for Jupjang. The acceptability of Jupjang was improved during the period of aging time.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.12
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• pp.1781-1789
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• 2013

Many studies have been carried out with respect to packaging methods and temperature conditions of beef. However, the effects of packaging methods and temperature conditions on the quality characteristics have not been extensively studied in low-grade beef. Low-grade beef samples were divided into 3 groups (C: ziplock bag packaging, T1: vacuum packaging, and T2: modified atmosphere packaging (MAP), $CO_2/N_2$ = 3:7) and samples were stored at $4^{\circ}C$ for 21 days. The water-holding capacity (WHC) was significantly lower in T1 than in the other samples up to 14 days of storage. The thiobarbituric acid reactive substances and volatile basic nitrogen values were significantly lower in T1 and T2 than in C after 7 to 14 days of storage. The total bacterial counts were significantly lower in T1 and T2 than in C after 14 days of storage. In a sensory evaluation, tenderness and overall acceptability were significantly higher in T1 and T2 than in C at the end of the storage period (21 days). We propose that the MAP method can improve beef quality characteristics of low-grade beef during cold storage. However, the beneficial effects did not outweigh the cost increase to implement MAP.