• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.192-197
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• 2000

To develop plain dried products of large anchovy, Engraulis japonica, lipid oxidation during drying of large anchovy and optimal drying condition were investigated. The moisture contents of large anchovy on 7 hrs dryness were $ 9.0{\%},\;34.0{\%},\;38.0{\%} and\;38.8{\%}\;in\;60^{\circ}C$ hot-air drying (wind velocity, 1.4m/sec), $40^{\circ}C$ hot-air drying (wind velocity, 1.4 m/sec), sun drying($30{\pm}5^{\circ}C$) and $20^{\circ}C$ cold-air drying (wind velocity, 3.1 m/sec), respectively. The cold-air drying depressed remarkably the lipid oxidation of large anchovy during drying, resulting from AV, POV, COV and the formation of browning pigment. The fatty acid composition of large anchovy was $35.8{\%} in saturates, 20.0{\%} in monoenes and 44.2{\%}$ in polyenes. Saturates and monoenes were increased in proportion to the increase of drying time, while polyenes were decreased. The contents of 20 : 5 and 22 : 6 of polyenes were decreased remarkably in proportion to the progress of lipid oxidation, while 14 : 0, 16 : 0, 16 : 1 and 18 : 1 of saturates and monoenes were increased. The changes in fatty acid compositions by drying conditions were remarkably clarified in sun drying, followed by $60^{\circ}C$ hot-air drying $40^{\circ}C$ hot-air drying and $20^{\circ}C$ cold-air drying in order.

• Tunnel and Underground Space
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• v.24 no.3
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• pp.224-233
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• 2014

It is well known that rock properties can be affected by loading in underground condition. In the case of flooded underground mine or tunnels, rock properties variation due to loading might be different from the loading in dry condition. In order to verify the influence of saturated loading condition on rock properties, various laboratory tests had been carried out. Loading on the rock specimen was controlled to be ranged in between 20 ~ 80% of UCS. By comparing the variation of thermal, mechanical, and physical properties of rock specimens under the same load in saturated and dry condition, it was possible to find that the rock properties can be more significantly disturbed in the saturated loading condition than in dry loading condition.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.1
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• pp.29-36
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• 2019

High-level radioactive waste (HLW) such as spent fuel is inevitably produced when nuclear power plants are operated. A geological repository has been considered as one of the most adequate options for the disposal of HLW, and it will be constructed in host rock at a depth of 500~1,000 meters below ground level with the concept of an engineered barrier system (EBS) and a natural barrier system. The compacted bentonite buffer is one of the most important components of the EBS. As the compacted bentonite buffer is located between disposal canisters with spent fuel and the host rock, it can restrain the release of radionuclides and protect canisters from the inflow of groundwater. Because of inflow of groundwater into the compacted bentonite buffer, it is essential to investigate soil-water characteristic curves (SWCC) of the compacted bentonite buffer in order to evaluate the entire safety performance of the EBS. Therefore, this paper conducted laboratory experiments to analyze the SWCC for a Korean Ca-type compacted bentonite buffer considering dry density, confined or unconfined condition, and drying or wetting path. There was no significant difference of SWCC considering dry density under unconfined condition. Furthermore, it was found that there was higher water suction in unconfined condition that in confined condition, and higher water suction during drying path than during wetting path.

• Journal of the Korean Geotechnical Society
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• v.19 no.2
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• pp.57-64
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• 2003

The liquefaction potential of saturated sands under seismic loading conditions has been carefully considered by many investigations. Typical of these investigations is the laboratory determination of cyclic strength of sands by means of cyclic triaxial tests. This study was conducted to investigate the effects of the method of sample preparation on the liquefaction characteristics of remolded samples of saturated uniform sands. Cyclic triaxial tests were performed on saturated uniform sand compacted to the same density by 3 different procedures of pluvial compaction through air, pluvial compaction through water and vibratory compaction. It was validated that the cyclic stress ratio of remolded saturated uniform sands by different compaction procedures at the same density was very different.

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

• Journal of the Korean GEO-environmental Society
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• v.9 no.1
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• pp.47-54
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• 2008

In this study, the effect of water content condition was investigated on the Mohr-Coulomb shear strength parameters which are commonly used as the input data in the soil slope analysis. For the purpose, a series of direct shear test was conducted in different water content conditions on the two types of weathered soils and a dam core material, obtained from the domestic slope construction sites and the dam construction site, respectively. The comparisons between the values of the Mohr-Coulomb ${\phi}_{peak}$ and $c_{peak}$, estimated from the relationships between the normal stress and the peak shear stress for the samples in the four different water content conditions (i.e., dry side, optimum, wet side, and saturated), showed that overall, the values of $c_{peak}$ decreased gradually while those of ${\phi}_{peak}$ did not vary much with increasing the water content. A rough estimate for the varying ratio of the values of ${\phi}_{peak}$ and $c_{peak}$ indicated that the values of $c_{peak}$ decreased by every 25% of the $c_{peak}$ values in dry side, while those of ${\phi}_{peak}$ were constant, as the water content condition changed from dry, optimum, and wet to saturated, respectively.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.1
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• pp.39-55
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• 2022

This study carried out the laboratory tests for AE signal attenuation to determine the attenuation coefficient (α) of silo concrete in Gyeongju low and intermediate-level disposal environments. The concrete samples were prepared by satisfying the concrete mixing ratio used in the Gyeongju disposal silo, and these samples were additionally exposed depending on the temperature conditions and saturation and, dry condition. As a result of attenuation tests according to the transmission distance on three concrete specimens for each disposal condition, the AE amplitude and absolute energy measured on the saturated concrete were higher than that of the dry concrete in the initial range of the signal transmission distance, but the α of the saturated concrete was higher than that of the dry concrete. Regardless of the saturation and dry conditions, the α tended to decrease as the temperature increases. The α had a more major influence on the saturation and dry condition than the temperature condition, which means that the saturation and dry condition is the main consideration in measuring the signal attenuation of a concrete disposal structure. The α of concrete in the disposal environment expect to be used to predict the integrity of silos concrete in Gyeongju low and intermediate-level disposal environments by estimating the actual AE parameter values at the location of cracks and to determine the optimum location of sensors.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.4
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• pp.103-111
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• 2009

Moisture is one of the important design factors that affects to the changes of physical properties and air permeability in the composting matrix. This study examines the effects of moisture during the wetting and drying procedure on physical properties like bulk density, particle size, free air space and air permeability in the sawdust used as the bulking agent in composting process. During both procedures of wetting and drying of the water, with increasing moisture content, bulk density and particle size increased, but FAS decreased. In the range of near 40 to 60% moisture content on a wet basis, particle size and FAS in wetting procedure were larger and higher than those in drying procedure. During wetting procedure, pressure drop continuously decreased ranging from near 20 to 60% moisture content, despite of decreasing FAS as a consequence of increasing moisture, and then over the range of 60% moisture content, pressure drop rapidly increased to the saturated moisture condition while the pore space was filled with the water. On the other hand, during drying procedure, pressure drop decreased from the saturated condition to 40% moisture content. In the recommended range of 50 to 60% moisture content for composting operation, pressure drop in wetting procedure were lower than in drying procedure. For the enhancement of the air permeability in the composting matrix, the wetting procedure was proper than the drying procedure, and the optimum moisture content for the efficient composting operation was appeared to be near 60%.

• Journal of the Korean GEO-environmental Society
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• v.13 no.3
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• pp.21-27
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• 2012

Estimating the thermal conductivity of clayey soils is important for enhancing the performance of geoengineering structures in cold regions and clay barriers for nuclear waste repositories, but specimen disturbance, saturation, and heat boundary conditions of the test apparatus hinder reliable measurements of the thermal conductivity of saturated clayey soils. This paper presents the results of an experimental study carried out using modified consolidation tests with the needle probe method to measure thermal conductivity. Experimental consolidation tests with saturated kaolinite were performed to investigate the effect of effective stress and dry density on thermal conductivity for saturated kaolinite. In addition, thermal conductivity of soil particles were thoroughly investigated and experimental results were used to evaluate the accuracy of the models to predict thermal conductivity.

• Journal of Conservation Science
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• v.30 no.4
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• pp.467-480
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• 2014

This study was focused on measurement methods for stone cultural heritages by analyzing Ultrasonic (P-wave) velocity variations according to the water content and anisotropy of rocks. As a result of analyzing of rock properties, the water content and saturation degree were rapidly changed at the beginning of drying and then showed exponential curve which their rates of change gradually decreased. However, P-wave velocity and its rate of change maintained constant values after natural drying of 10 hours. Therefore, the ultrasonic measurement for stone cultural heritages should be performed after natural drying of 10 hours considering the weather and moisture conditions. In addition, the highest values of anisotropy coefficient exhibited in granite and limestone, and indirect method was insensitive to anisotropy compared to direct method. However, all rocks remained anisotropy by indirect method. Accordingly, ultrasonic measurement considering various directions is required. The research results will contribute to customized non-destructive testing and precise diagnosis for lithological characteristics of stone cultural heritage.