• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.1
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• pp.151-165
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• 1996

Relation between condensate retention and heat transfer performance is studied for condensation of CFC-11 on horizontal integral-fin tubes. Eight tubes with trapezoidally shaped integral fin density from 738fpm to 1654fpm and 10, 30 grooves are tested. The liquid retention angles are measured by the height gauge, and each tube is tested under static(non-condensing) condition (CFC-11, water) and under dynamic(condensing) condition (CFC-11). The analytical model predicts the amount of liquid retention on a horizontal integral-fin tubes within＋10 percent over most of the data. Average retention angle increases as both surface tension-to-density ratio($\sigma/\rho$) and fin density(fpm) increase, The tube having a fin density of 1299~1654fpm has the best heat transfer performance. The amount of surface flooding must keep below of 40 percent for best heat transfer performance at condensation. The tube having low number of fin density must be used for fluids having high values of $\sigma/\rho$(water, (TEX)$NH_3$, ect.) and the tube having high number of fin density must be used for the fluid having low values of $\sigma/\rho$(R-11, R-22, etc.)

• Journal of Korean Society of Disaster and Security
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• v.15 no.1
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• pp.23-34
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• 2022

Korea Government promotes the installation of buffering retention facility to protect the water environment and prevent the environmental contamination event by toxic materials. Although the buffering retention facility is very important to protect the natural environment through the retention of accidental pollution and initial runoff, much study has not been done to suggest the guide line for the design of the facility. In this study, we suggested the rational items for the design of buffering retention facility based on many experts after we investigated and compared the previous results of many design materials.

• Journal of the Korean GEO-environmental Society
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• v.14 no.1
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• pp.69-75
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• 2013

Suction stress is evaluated from soil water retention curves in order to deduce effective stress in unsaturated soils. $K_0$ consolidated triaxial tests were performed for silty sand to interpret effective stress in consolidation and shearing of unsaturated soils. Suction stresses from both consolidation stress and shear strength in triaxial tests were compared with those from soil water retention curves. The effective stresses on consolidation and shear strength are on each unique line, which are the same as that of the saturated case. It was found that the effective stress from soil water retention curves agrees with those from consolidation and shear strength in triaxial tests.

• Journal of the Korean Geotechnical Society
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• v.37 no.1
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• pp.17-27
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• 2021

It takes a long period to conduct the test on soil water retention curve (SWRC) in unsaturated soils. To improve such a problem, the high air entry disk has been replaced by micro-membrane. After the soil water retention test, the results by the micro-membrane were compared with those by the ceramic disk. Multiple samples in 5 regions were used to validate that SWRCs by micro-membrane are equivalent to those by ceramic disk. Therefore, a quick procedure based on micro-membrane has been developed, which makes it available to acquire much soil water retention data. The data of SWRCs were obtained for total 29 samples using ceramic disk or micro-membrane. For Korean weathered soils, the unsaturated hydraulic characteristics are sorted by three groups. Based on van Genuchten model, the group is divided by the parameter n, and the value of n could be correlated to the void ratio as each function.

• Journal of the Korean Society of Food Culture
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• v.37 no.1
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• pp.47-60
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• 2022

This study examines the effects of different cooking methods (stir-frying, steaming, superheated-steaming) on the contents and the true retention of moisture, water-soluble vitamins, and bioactive compounds of ten selected vegetables: broccoli, brussels sprout, cabbage, eggplant, green bean, onion, red cabbage, red onion, squash, and tomato. The total color difference (𝚫E) values were decreased after stir-frying the samples, except for eggplant, green bean, and tomato. The true retention of water-soluble vitamins (B₁, B₂, B₃, and C) was increased in most vegetables after superheated-steaming, as compared to steaming and stir-frying. Moreover, compared to the uncooked vegetables, a higher true retention of total polyphenol and flavonoid was obtained for most vegetables subsequent to superheated-steaming. Total anthocyanin content was detected only in eggplant, red cabbage, and red onion, and a smaller loss of anthocyanin was determined after subjecting red cabbage to superheated-steaming. Also, the free radical scavenging activities were higher in superheated-steaming vegetables, except in eggplant and squash. These results indicate that superheated-steaming induces a positive effect for retaining water-soluble vitamins and functional components of vegetables.

• Korean journal of food and cookery science
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• v.32 no.3
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• pp.270-278
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• 2016

Purpose: We have investigated for the purpose of studying change of vitamins and minerals in frequently used vegetables by low moisture cooking method. Methods: Vitamin B complex, vitamin C and mineral (Mg, Ca, K, Zn, Fe) contents are analyzed in vegetables such as spinach, cabbage, bean sprouts and carrot which are heat-treated with degrees of water contents. Low moisture cooking method represents heat-treated vegetable (LM experiment group) with 25 wt.% water content for the vegetable weight while general blanching method includes heat-treated vegetable (GB experiment group) with 500-1,000 wt.% water content for the vegetable weight. Results: Retention rate of vitamin B1 (thiamin) in the LM experiment group is relatively high (87.50-95.68%) and dosen't show considerable differences from raw vegetables. On the other hand, the retention rate of vitamin $B_1$ in GB group's cabbage and spinach dramatically decreased to 19.46-25.00%. Retention rate of vitamin B2 (riboflavin) is sustained stably in LM experiment group (75.00-87.50% in bean sprouts, cabbage and spinach), represents that low moisture cooking method has relatively higher contents in vitamin $B_2$. The LM experiment group has 71.43-85.71% on retention rate of niacin while the GB group shows relatively lower niacin (57.14-64.58%), represents conflicting results from the general idea that vitamin $B_3$ is relatively stable in heat treatment and blanching. Retention rate of pantothenic acid is considerably higher in both LM and GB experiment group, indicates vitamin pantothenic acid is relatively stable in the various cooking condition such as amount of water and heat treatment. In the experiment under various water contents, vitamin C is not detected in both bean sprouts and carrots, while the contents in cabbage and spinach are 19.87 mg/100 g and 26.65 mg/100 g respectively. In the same experiment, the retention rate of Vitamin C in LM experiment group (91.65%, 92.23%) is considerably higher than GB group (58.08%, 61.61%). Retention rate of Mg, K, Fe in the LM experiment group is relatively higher than GB group. Conclusion: Resultingly, the observations suggests that minimum water quantity and minimum heat treatment processes should be established in cooking vegetables which have soluble vitamins and minerals.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.979-984
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• 2008

In this study, 8 solutes (aniline, caffeine, p-cresol, ethyl benzene, methylparaben, phenol, pyridine, and toluene) have been tested in terms of linear solvation energy relationships (LSER). Several micellar liquid chromatography (MLC) systems using cationic surfactant cetyltrimethylammonium bromide (CTAB) and a mixture of water with (methanol, n-propanol, and n-butanol) modifiers were characterized using the LSER solvation parameter model. The effects of the surfactant and modifier concentration on the retention in MLC were discussed. LSER model had demonstrated high potential to predict retention factors with high squared correlation coefficients ($r^2$ > 0.99). A comparison of predicted and experimental retention factors suggests that LSER formalism is able to reproduce adequately the experimental retention factors of the solutes studied in the different experimental conditions investigated. This model is a helpful tool to understand the solute-surfactant interactions and evaluate the retention characteristic of micellar liquid chromatography.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.3
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• pp.617-628
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• 2001

Cotton and silk fabrics dyed with brazilein(Caesalpinia Sappan), berberine (Phellodendron Amurense), and shikonin(Lithospermum Erythrorhizon) were stored in the air, in the water, and under the ground for about one year. The change of the color, the flexibility, and the breaking strength were measured at the intervals of few weeks. The results are as follows; 1. The color of the fabrics changed most extensively in the fabrics that were under the ground, then in the order of the ones that were in the water, and in the air. The color of the fabrics changed to the achromatic color over the time. 2. The flexibility change among the dyes was similar. All the fabrics became stiff under the ground and in the water over the storage time. 3. In general, cotton and silk fabrics dyed with berberine showed better strength retention than the fabrics dyed with other substances. 4. The strength retention of cotton fabrics was high in the order of the fabrics which were in the air, in the water, and under the ground. Only minuscule change occurred in the strength of the cotton fabrics. The strength of the fabrics that were in the water and under the ground decreased remarkably after 30 weeks and 20 weeks respectively. 5. The strength retention of silk fabrics was high in the order of the fabrics which were in the air, under the ground, and in the water. In the air, the strength on silk fabrics decreased rapidly after 30 weeks. In the water, the strength of silk fabrics decreased more rapidly than that of the cotton fabrics. Under the ground, the strength retention of silk was higher than that of cotton.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.E1
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• pp.12-23
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• 2008

Relationship between the optimum soil water content and clay content on soil samples from mid-latitude European forest was tested. Soil samples from 4 different experimental sites (two forest sites in the Netherlands and a Danish forest) were collected, and analyzed for the soil physical and chemical characteristics. Water retention curves for the soil samples were determined according to the standard procedure ISO 11274, and pF decreased with increase in soil water contents. NO is simultaneously produced and consumed by microbiological processes, which comprise of nitrification and denitrification. NO consumption and production rates were determined from the soil samples and compared to their corresponding water retention curves in order to find the optimum soil water content and matric potential for maximum NO release from mid-latitude soils. NO consumption rate coefficient (k) in Hollandse Hout was significantly lower than those in other soil sites. Maximum NO production was observed at an intermediate soil moisture ($0.2{\sim}0.3kg/kg$) in all the soil samples. Resulting from the NO consumption and production rates for the soils, the empirical NO fluxes of the different soils were calculated in the laboratory.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.5
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• pp.340-344
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• 2014

Compost and gypsum can be used to ameliorate soil physicochemical properties in reclaimed tidal lands as an organic and inorganic amendment, respectively. To evaluate effects of compost and gypsum on soil water movement and retention as a soil physical property, we measured the soil's saturated hydraulic conductivity and field capacity after treating the soil collected in a reclaimed tidal land with compost and gypsum. Saturated hydraulic conductivity of soil increased when compost was applied at the conventional application rate of $30Mg\;ha^{-1}$. However, the further application of compost insignificantly (P > 0.05) increased saturated hydraulic conductivity. On the other hand, additional gypsum application significantly increased soil saturated hydraulic conductivity while it decreased soil field capacity, implying the possible effect of gypsum on flocculating soil colloidal particles. The results in this study suggested that compost and gypsum can be used to improve hydrological properties of reclaimed tidal lands through increasing soil water retention and movement, respectively.