• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.4
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• pp.174-181
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• 2021

Lightweight geopolymers were fabricated by using IGCC (integrated gasification combined cycle) slag and Si sludge which are classified as general wastes (recyclable resources). Three curing methods were tried to investigate the changes in compressive strength and density according to the curing method and immersion time. Immersion period was tried up to 21 days to observe long-term performance in water. Compressive strength of the specimens cured in oven decreased abruptly with an increase in immersion time. Compressive strength of the specimen cured in autoclave was low after 3 and 7 day immersion; however, increased rapidly after 21 day immersion. On the contrary, compressive strength of the specimen cured in autoclave and oven was high but substantially decreased after 21 day immersion. Conclusively, it was speculated that oven curing is effective for the compressive strength development at early age; however, autoclave curing is more desirable for the long-term performance in water.

• Journal of Ocean Engineering and Technology
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• v.28 no.1
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• pp.64-68
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• 2014

This study was conducted to investigate the durability of carbon fiber/epoxy composites (CFRP) in a saline water environment. The carbon fiber/epoxy composites were modified to use nanoparticles such as carbon nanotubes and titanum oxide. These hybrid composites were exposed to a saline water environment for a certain period. The weight gain according to the immersion time, a quasi-static tensile test, and micro-graphic characterization were used to investigate the samples exposed to the saline water environment. The weight gains increased with increasing immersion time. The weight gains of the hybrid composites were lower than that for pure CFRP throughout the entire immersion time. The tensile strengths decreased with increasing immersion time. The tensile strengths of the hybrid composites were higher than that of the pure CFRP throughout the entire immersion time. The pure CFRP was observed to be more degraded than the hybrid composites in the saline water environment. Therefore, it was concluded that the addition of nanoparticles to CFRP could lead to improved durability in a saline water environment.

• Journal of Power System Engineering
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• v.18 no.2
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• pp.43-49
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• 2014

This study has been investigated on the durability of carbon fiber/epoxy composites (CFRP) in moisture environment. The carbon fiber/epoxy composites were modified to use the nanoparticles such as carbon nanotubes and titanium oxide. These hybrid composites were exposed to moisture environment for a certain period of time. Weight gain according to immersion time, quasi-static tensile test and micro-graphic characterization were investigated on the samples exposed to moisture environment. Consequently, the weight gains increased with increasing immersion time and weight gain of the hybrid composites was lower than the one of CFRP through the whole immersion time. The tensile strengths decreased with increasing immersion time and tensile strengths of the hybrid composites were higher than the one of CFRP through the whole immersion time. The CFRP were observed more degraded than hybrid compositess in moisture environment. Therefore, it was concluded that the addition of nanoparticles in CFRP could lead to improve the durability in moisture environment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.648-652
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• 1998

Astringency in persimmons was removed by immersing in 0.5% acetic acid or various concentrations(0.1%, 0.5%, and 1.0%) of chitosan solutions for 4 days at 18$^{\circ}C$. During 5-days immersion, soluble tannin contents in persimmons decreased more rapidly while pH, 。Brix, and hardness decreased more slowly with increasing chitosan concentration. No noticeable color changes and decay were observed during this period. Sensory analyses 4 days after immersion indicated that persimmons immersed in 1.0% chitosan solution showed the best results for firmness and overall acceptability.

• Journal of the Korean Society of Food Culture
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• v.36 no.3
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• pp.265-273
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• 2021

The Chinese Sigyeong records the foods of the Primitive Pickling Period, pickling being a universal vegetable storage method, but does not indicate the origin of the pickled vegetables or the location of the source of transmission. Kimchi mainly used salt and sauce-based soaking materials at the beginning of the Fermented Pickling Period (beginning in the 1st to 3rd centuries A.D.), and it differed from the Chinese method, which used alcohol and vinegar. In the Umami-Flavored Pickling Period (beginning in the 14th and 15th centuries A.D.), jeotgal, fermented seafoods, were added, and pickles with a completely new identity were created, one different from any other pickles in the world. Lastly, entering the Complex Fermentation and Pickling Period (beginning in the 17th and 18th centuries), the technical process evolved using a separate special seasoning containing red pepper as the secondary immersion source after pickling in brine, the primary immersion source. As a result of this, kimchi was transformed into a food with a unique form and taste not found anywhere else. The unique characteristic of kimchi is that the composition of original materials, a combination of salted marine life and vegetable ingredients, is its core identity, and there is a methodological difference in that it is completed through a second process called saesaengchae (生菜)-chimchae (沈菜).

• Journal of Ocean Engineering and Technology
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• v.13 no.4 s.35
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• pp.63-74
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• 1999

This study has been investigated about the influence of moisture environment on the mechanical properties in the carbon fiber cross laminates. And it has been also investigated the effect of unit ply thickness of the carbon fiber cross laminates on the mechanical properties in distilled water of $80^{\circ}C$ for a certain period of time. As a results, it was found that the weight gain of water was increased with the immersion time and the bending strength and fracture toughness were decreased with the weight gain of water. And it was also shown that the bending strength and fracture toughness were decreased with the increasing of the unit ply thickness of carbon fiber cross laminates through the immersion time.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.903-907
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• 1998

Mass transfer characteristics during osmotic dehydration of mushrooms(Agaricus bisporus) in sugar solution were studied as a function of sugar concentration, immersion time and temperature, and the effect of osmotic dehydration on browning inhibition of air-dried mushrooms was also evaluated. Increasing the sugar concentration, immersion time and temperature increased moisture loss, sugar gain, molality and rate parameter. The changes of sugar gain and rate parameter were more significantly affected by concentration than by temperature of sugar solutions, while 1$0^{\circ}C$ increase in temperature or 10 Brix increase in concentration had the same effect on water loss. Water loss, sugar gain, molality were rapid in the first period of osmotic dehydration especially in the case of higher concentration and temperature of sugar solutions. Effects of osmotic dehydration in sugar solution(60 Brix, 8$0^{\circ}C$) with 18 min of immersion time(O.D.=0.099) rior to air dehydration on browning inhibition of dried mushrooms were more significant than blanching in water(8$0^{\circ}C$) with the same immersion time(O.D.=0.330) and the control (O.D.=0.559).

• Journal of Korea Entertainment Industry Association
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• v.14 no.5
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• pp.115-130
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• 2020

The purpose of this study is to analyze the difference between A Study on the Weight Change and Exercise Immersion for Activation of Aerobic Dance and to suggest the continuous activation of Aerobic Dance. To achieve this purpose, a questionnaire was conducted using a convenience sampling method, which is one of non-probability sampling, in April 2020, targeting general aerobic dance members in Gyeongnam. The results of this study are as follows. First, the demographic characteristics were partially different. The age was 40 to 49 years, height was more than 160cm, occupation was housewives, weight change was more than -3kg, participation intensity was more than 100 minutes, participation frequency was 4 days, and participation period was less than 5 years. Second, the results of this study are as follows: Weight Change(Body Confidence, Activity Confidence, Dance Confidence, Psychological Stability Effect, Dance Activity Effect, Perform-motion Effect) and Exercise Immersion(Behavior immersion, Cognitive immersion) were partially high There was a difference. Third, the results of this study are as follows: Weight Change(Body Confidence, Activity Confidence, Dance Confidence, Psychological Stability Effect, Dance Activity Effect, Perform-motion Effect) and Exercise Immersion(Behavior immersion, Cognitive immersion) were partially high It was shown that the influence was.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.1
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• pp.1-10
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• 2022

This study was conducted to investigate the germination characteristics through the temperature change treatment compared to the general room temperature immersion treatment of the native species, the Larix kaempferi, and the Berula platyphyllavar. japonica seeds, and to obtain basic data for the production of healthy seedlings with high productivity and efficiency. As a result, the germination rate of the larch seeds showed a significant difference according to room temperature and temperature immersion treatment, and the average germination days of the birch seeds showed a significant difference according to room temperature immersion and temperature immersion treatment. On the other hand, there was no significant difference in germinal uniformity. The results of the study are as follows. First, the results of the analysis of the fallen leaves were the highest germination rate in the treatment of 1.5 days of hot water and 1.5 days of cold water, the fastest germination rate, the lowest average germination day, and the highest germination uniformity. This is the best result in most items, and the change temperature immersion treatment of hot and cold baths was superior to the conventional room temperature immersion treatment. Second, the results of birch tree showed that the germination rate was the highest in 1.5 days of hot water and 1.5 days of cold water. The average germination day is 1.5 days of cold water 1.5 days of hot water 1.5 days, but the difference between 1.5 days of hot water and 1.5 days of cold water is 0.01 days. The highest germinated uniformity was found in 1.5 days of cold water and 1.5 days of hot water. As a result, in the case of larch and birch, the seed temperature immersion (1.5 days of hot water, 1.5 days of cold water) treatment is superior to the existing three-day immersion treatment in various analysis methods, and it is expected that productivity and efficiency can be improved at a low cost in a short period of time at the seedling production site through seeds.

• Corrosion Science and Technology
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• v.6 no.4
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• pp.147-153
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• 2007

This study sought to investigate the reaction of Co-binder containing tungsten with molten zinc. Four kinds of Co-W alloys (pure, 10%W, 20%W, 30%W) were prepared using the powder metallurgy method. The specimens were immersion-tested in molten pure zinc baths at $460^{\circ}C$. To evaluate the corrosion property in molten zinc, the weight loss of the specimen was measured after the immersion tests at different immersion times (10~300 min.). Co-10%W alloys, compared with pure cobalt, showed no effect of tungsten addition on the reaction rate in molten zinc. The relationship between the weight loss and the square root of immersion period represents a straight line in both pure cobalt and Co-10%W alloy. The Co-Zn reaction layer in Co- 1O%W alloy consists of $\gamma2$, $\gamma1$, $\gamma$ and ($\beta1$ phases. The rate of weight loss significantly increases and the weight loss behavior is not well accord with the linear relationship as the tungsten content in the Co-W alloy increases. The $\beta1$ layer was not formed on the Co-20%W alloy and neither was a stable Co-Zn intermetallic compound layer found on the Co-30%W alloy. The main cause of increase in reaction rate with increasing tungsten content is related with the instability of the Co-Zn reaction phases as seen on micro-structural analysis.