• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.1
• /
• pp.125-132
• /
• 2020

The causes of concrete shrinkage are very diverse, in particular, aggregates impact the characteristics of shrinkage in concrete by constraining the shrinkage of cement paste. Meanwhile, owing to the lack of natural aggregate, various alternative aggregates are being developed, and their application in concrete also becomes more diverse. This study aimed to experimentally evaluate the drying and autogenous shrinkage in concrete that was composed of electric arc furnace slag as coarse aggregates. And, the results were compared with prediction models. From the results, the application of electric arc furnace slag can reduce the drying and autogenous shrinkage. In particular, autogenous shrinkage is greatly decreased. The predictions using GL2000 for drying shrinkage and Tazawa model for autogenous shrinkage were similar to the experimental results. However, the most prediction models do not consider the impact of aggregates, hence, the new prediction model should be developed or improved.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.4 no.1
• /
• pp.31-41
• /
• 1971

The present study was directed to define the degradation pattern of the nucleotides and their related compounds in the muscle of anchovy during drying. Three kinds of samples, fresh, sun dried and boiled-and-dried anchovy, were prepared and the contents of nucleotides and related compounds of samples were determined by ion exchange chromatography. The results obtained are summarized as follows: Almost all of ATP disappeared in both muscle of sun dried and boiled-and-dried anchovy, although the initial content of ATP in fresh muscle was very low ($1.8{\mu}moles/g$, dry basis). But the remainning amount of ADP was considerably high while the other nucleotide almost entirely disappeared. This suggested that the residual ADP is responsible to the 'bound nucleotide' of myofibrils. In general, AMP content was comparatively lower than that of other nucleotides. Among three samples, the boiled-and-dried sample showed relatively higher AMP value than others. The amount of IMP remained in muscle remarkably varied between the boiled-and-dried anchovy and sun dried anchovy, the former's value being sixteen times higher than that of latter. In the contents of inosine and hypoxanthine, the sun dried anchovy marked an exceedingly high value equivalent to 2.7 times of the boiled-and-dried anchovy. In comparison of the ratio of inosine and hypoxanthine, hypoxanthine was accumulating in boiled-and-dried anchovy whereas inosine was in the sun-dried anchovy. Eighty three percent of total nucleotides in the fresh anchovy retained in the boiled-and-dried anchovy and IMP ratio in total nucleotides was $73\%$. On the contrary, the sun dried anchovy showed barely $10\%$ of retention rate and IMP ratio was only $38\%$. Considered from the flavor quality of dried anchovy, so far as concerned IMP content, it may be said that the boiled-and-drying method is more favorable process for dried product of anchovy than the sun-drying method.

• Korean Journal of Plant Resources
• /
• v.8 no.2
• /
• pp.115-125
• /
• 1995

The moistures, colors and flavors of red pepper were analyzed to observe the changes of the qualities of red pepper with various conditions of drying. The moisture was 11.8%, known as optimal condition for storing red pepper, where dried at $50^{\circ}C$ for 36 and 48 hours. The color of red pepper air-dried at 50% for 48 hours was estimated to be the most execllent in comparison of sun drying and air drying. The optimal absorbances of hexnae extract from red pepper were examined. The ratios between the absorbances at 280nm and at the typical wavelengths of caretenoids(430nm, 450nm, 474nm) were from 2.5-3.4 and these wete also confirmed by the sight of the eye. Hexane fraction showed more peaks of flavors than benzene fraction and both of the two were silylated by with BSTFA to analyze the flavors by GC. CG profiles for the compositions of flavors in red perpper are thought to be useful for extimating the quality of favors in red pepper. Eight flavors including benzene dicarbozylic acid, were identified from red pepper and major components of them were oleic palmitic acids. Drying temperatures and times did not have effects on the changes of specific flavor components but did influenced the compositions of them in red pepper.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.15 no.4
• /
• pp.403-409
• /
• 2017

For dry storage of the spent nuclear fuel (SNF) stored in the storage pool of a nuclear power plant, essentially all moisture must be removed to prevent corrosion of the assembly and canister internals and/or degradation of fuel cladding integrity after SNF canister loading operation. R&D work is now in progress on a forced gas drying system that can be used to remove residual water in canisters. In this work, preliminary design is performed to manufacture the forced gas drying system. This process includes a case study of dry methods for canister moisture removal, relative codes and standards, confirmation of adequate dryness, needs analysis at plant sites, and characteristics of SNF stored in pools. Through this preliminary design work, we obtained a conceptual flow diagram and preliminary P&ID of the forced gas drying system. The results of this study can be used to determine details of the design to manufacture the forced gas drying system.

• Journal of the Korean Wood Science and Technology
• /
• v.46 no.5
• /
• pp.610-621
• /
• 2018

In conservation treatment lacquer has been used variously as a restoration material. However, dealing with Lacquer is very difficult as it dried in high humidity that can be harmful to the base materials. Also being natural varnish, dried lacquer layer is very different from the drying condition and the quality of the lacquer. These make difficult to predict the result of drying lacquer. In this study, using the humidity control machine, firstly, the main contents of the two different type of lacquer was experimented. And these lacquers was cured in various conditions. The duration time was checked until totally hardened. After that, obtained lacquer layers was analyzed to understand optical properties. Therefore, this study made a result about the relationship between characteristics of lacquer layer and the hardening condition. As a result, duration time of the Korean lacquer drying which has average 13.4% more urushiol than the Chinese lacquer is recorded a twice or triple decrease over it of the Chinese one. And, in all types of lacquer, the higher humidity makes the faster a pace of lacquer dried. In same lacquer, the shorter the duration time of drying lacquer is much darker and glossier. However, gloss deteriorated in saturated humidity. In humidity lower than RH 70%, lacquer is not hardened in 336 hours. When the layer totally cured through long period more than 30 days, the drying lacquer is appeared high brightness and almost transparent. Thus, in lower than RH 70%, it is hard to obtain durable layer.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.5
• /
• pp.753-758
• /
• 1997

Dried alaska pollack is one of the representatives among dried marine fish and shellfish products in our country. This study was performed to obtain the basic data about the effect of drying method on the formation of N-nitrosamine and its precursor to ensure the safety of dried alaska pollack. The contents of nitrate and nitrite were detected 1.5 and <1.0 mg/kg in raw samples, and $3.0\~4.2,\;1.4\~2.7mg/kg$ in dried products, respectively. There was no significant change of betaine contents during drying while TMAO decreased, TMA and DMA increased in alaska pollack during d교ing. N-nitrosodimethylamine (NDMA) was only detected in alaska pollack and its dried products, and recovery from above samples spiked with $10{\mu}/kg$ for N-nitrosodipropylamine was $87.2\~107.4\%$. The levels of NDMA were found to be $2.8{\mu}/kg$ on an average in raw samples, but the levels of NDMA increased remarkably during drying of alaska pollack and its content in dried products was $8.7\~51.4{\mu}g/kg$. Regardless of drying methods, NDMA tend to increased in dried products, and its contents were 15.5 times higher in hot-air dried than raw samples, 9.0 times in sun dried and 4.4 times in freeze dried products. less NDMA was produced in the freeze dried products, so it is believed that freeze drying method is effective to decrease the NDMA levels in the dried products of alaska pollack.

• Food Science and Preservation
• /
• v.23 no.1
• /
• pp.1-6
• /
• 2016

The physiological activities of 70% ethanol extracts of grape seed (GS) prepared by freeze-drying (GSFD), infrared drying (GSIR), hot-air drying (GSHD), or sun-drying (GSSD) were investigated. The moisture contents of GSFD, GSIR, GSHD and GSSD powders were 4.53, 6.71, 6.91 and 5.55% respectively. Hunter's color value analysis revealed that the $L^*$ value of GSIR was lower, and the $a^*$ and $b^*$ values of GSIR were higher, than those of GSFD, GSHD, and GSSD. The total polyphenol and proanthocyanidin contents of GSFD were significantly higher than those of the other extracts. The flavonoid related substance contents were in the order of GSFD (7.68 g/100g) = GSSD (7.59 g/100g) = GSHD (7.33 g/100g) > GSIR (6.45 g/100g). The electron donating abilities of $500{\mu}g/mL$ solutions of GSFD, GSIR, GSHD and GSSD were 88.71, 52.62, 65.20, and 65.22%, respectively, while their reducing powers ($OD_{700}$) were 1.633, 1.097, 1.217 and 1.054 absorbance units, respectively. Additionally, the same trend was observed for the ABTS radical-scavenging abilities of the extracts as that observed for their electron-donating abilities and reducing powers. These results suggest that GSFD is the best method for preparing GS extracts with enhanced antioxidant activities, and that GS extracts may be used as a natural antioxidant material for use in health foods.

• Journal of the Korean Wood Science and Technology
• /
• v.30 no.4
• /
• pp.27-32
• /
• 2002

We investigated the effect of polyethylene glycol(PEG) treatment of preservative treated green japanese cedar(Cryptomeria japonica) round posts on their preservative penetration and check formation during the air drying. The round rods were dip-treated in 10% preservative solution of Basilit CFK for 1 day, followed by application(3, 5, and 10 times) with 50% PEG-400 solution, and then dried for 30 days under natural conditions. The rate of preservative penetration into sapwood was a low by 23.2% without PEG treatment, whereas that was a high by about 51.2~64.5% with PEG treatment. From these results, it was assumed that PEG played an affirmative role in the penetration of preservative components loaded onto the surface of round rods by dipping. During the air drying, the formation of drying checks decreased significantly with increasing application times of PEG. Even though some drying checks in PEG treated rods were developed, the number and size of checks was reduced remarkably by PEG treatment. After 2 months of outdoor exposure, PEG treatment failed to reduce checking in preservative-treated rods whereas finishing of polyurethane resin lacquer after PEG treatment was significantly effective in preventing check development.

• Journal of Food Hygiene and Safety
• /
• v.22 no.4
• /
• pp.300-305
• /
• 2007

The purpose of this study is to examine changes in the residues of procymidone and diazinon in Chwinamul, pepper leaves, and young radish according to drying method. When the three vegetables were dried at room with air stream, the residues of procymidone and diazinon increased, but after being adjusted to reflect the decrease in water content of the vegetables, the residues declined by 10 to 83 percent. When they were dried in a oven, the residues of the pesticides in the vegetables also increased, but after being adjusted to reflect the drop in the water content, the residues decreased by 44 to 71 percent. According to the results, the residues of the pesticides mostly decreased after being adjusted to reflect the drop in the water content of the dried vegetables. Therefore, when judging dried agricultural products not only the decreased water content of dried vegetables but also other factors that affect pesticide residues during the drying process should be considered. This raises the need for additional research on such factors.

• Korean Journal of Food Science and Technology
• /
• v.10 no.4
• /
• pp.398-403
• /
• 1978

Squid was dried on the fluidized-bed in the drying chamber filled with solid particles which were also fluidized with hot-air, and effects of the fluidized particles, the squid's height from the grid and the drying temperature on the drying rate and quality of the squid were observed The mechanism of moisture transfer during the falling rate period was also derived. 1. Sodium chloride was found to be the most suitable fluidized particles and at an air velocity of 3.8 m/sec, optimal fluidization state of this particle was obtained. 2. Uniform profiles of temperature were obtained at a point 4 cm above the grid and the location of squid on the fluidized-bed observed to be suitable when it was 4 cm above the grid. 3. At an air velocity of 3.8 m/sec and when the location height of the squid on the fluidized-bed was 4 cm, the optimal temperature for the drying time which is required to reduce the moisture from 80.8% to 18-22% was 8.5 hours. 4. Drying data followed the empirical equation of unsteady state diffusion $log\;(\frac{W-We}{Wc-We})=-m{\theta}$ in the region of the moisture contents measured and the drying constant (m) was calculated as $0.32hr^{-1}$. These results suggested that the migration of moisture during the falling rate period is due to a diffusion type mechanism. 5. The short constant rate period was observed in the early stage and thereafter, drying was controlled by the falling rate period, and the time ratio of the fluidized bed drying to the through circulation drying for reducing the squid's moisture contents to the same level at the same drying temperature was 1 : 1.4 6. Comparisons of fluidized-bed dried squid and sun dried squid in sale showed that there was no significant change in qualities such as external appearance and hydrogen ion concentration of dry product.