• Journal of the Korean Society of Food Culture
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• v.34 no.4
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• pp.449-455
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• 2019

The purpose of this study was to develop a peach spread premix to increase the usability of peaches with low storage stability. We analyzed the effect of adding different ratio of peach powder (0, 5, 10, 15%) on the physicochemical and sensory quality characteristics of peach spread premix. The result showed that the pH of the spread premix significantly decreased with the addition of greater amounts of peach powder (p<0.05). The total titratable acidity (TTA) and sweetness of the peach spread premix were significantly increased as the amount of added peach powder increased (p<0.05). The redness (a-value) and yellowness (b-value) increased with an increase of the peach powder ratio; however, the lightness (L-value) decreased (p<0.05). The water activity and viscosity of the spread decreased with an increased amount of added peach powder. The results of the sensory test with spread premix prepared with 10% peach powder had the highest score for color, taste, texture, stickiness, and overall acceptability (p<0.05). We suggested that the peach spread premix made with 10% peach powder may be the most desirable for manufacturing spread premix and for improving sensory preference.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2019.10a
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• pp.134-134
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• 2019

Utilization of organic waste as a renewable energy source is promising for sustainability and mitigation of climate change. Pyrolysis converts organic waste to gas, oil, and biochar by incomplete biomass combustion. Biochar is widely used as a soil conditioner and adsorbent. Biochar adsorbs/desorbs metals and ions depending on the soil environment and condition to act as a nutrient buffer in soils. Biochar is also regarded as a carbon storage by fixation of organic carbon. Phosphorus (P) and nitrogen (N) are strictly controlled in many wastewater treatment plants because it causes eutrophication in water bodies. P and N is removed by biological and chemical methods in wastewater treatment plants and transferred to sludge for disposal. On the other hand, P is an irreplaceable essential element for all living organisms and its resource (phosphate rock) is estimated about 100 years of economical mining. Therefore, P and N recovery from waste and wastewater is a critical issue for sustainable human society. For the purpose, intensive researches have been carried out to remove and recover P and N from waste and wastewater. Previous studies have shown that biochars can adsorb and desorbed phosphates implying that biochars could be a complementary fertilizer. However, most of the conventional biochar have limited capacity to adsorb phosphates and nitrate. Recent studies have focused on biochar impregnated with metal salts to improve phosphates and nitrate adsorption by synthesizing biochars with novel structures and surface properties. Metal salts and metal oxides have been used for the surface modification of biochars. If P removal is the only concern, P adsorption kinetics and capacity are the only important factors. If both of P and N removal and the application of recovery are concerned, however, P and N desorption characteristics and bioavailability are also critical factors to be considered. Most of the researches on impregnated biochars have focused on P removal efficiency and kinetics. In this study, coffee waste is thermally treated to produce biochar and it was impregnated with Mg/Al to enhance phosphates and nitrate adsorption/desorption and P bioavailability to increase its value as a fertilizer. Kinetics of phosphates and nitrate adsorption/desorption and bioavailability analysis were carried out to estimate its potential as a P and N removal adsorbent in wasewater and a fertilizer in soil.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5B
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• pp.481-488
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• 2006

This paper suggests a novel approach of integrating the quasi-distributed watershed model SWAT with the fully-distributed groundwater model MODFLOW. Since the SWAT model has semi distributed features, its groundwater components hardly considers distributed parameters such as hydraulic conductivity and storage coefficient. Generating a detailed representation of groundwater recharge, head distribution and pumping rate is equally difficult. To solve these problems, the method of exchanging the characteristics of the hydrologic response units (HRUs) in SWAT with cells in MODFLOW by fully combined manner is proposed. The linkage is completed by considering the interaction between the stream network and the aquifer to reflect boundary flow. This approach is provisionally applied to Gyungancheon basin in Korea. The application demonstrates a combined model which enables an interaction between saturated zones and channel reaches. This interaction plays an essential role in the runoff generation in the Gyungancheon basin. The comprehensive results show a wide applicability of the model which represents the temporal-spatial groundwater head distribution and recharge.

• Journal of The Geomorphological Association of Korea
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• v.28 no.1
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• pp.13-33
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• 2021

Successful sediment management at the watershed scale requires an understanding of the erosion, transport and sedimentation processes at the specific site scale. However, studies on the sediment runoff characteristics in a small uppermost watershed, which serves as a sediment supply function, are very rare. Therefore, this study attempted to investigate the fluctuations in major sediment supply areas and sediment runoff in the uppermost mountain small watershed, and for this purpose, ArcSWAT (Soil and Water Assessment Tools with GIS interface) was applied to the Woldong reservoir catchment located in Gosam-myeon, Anseong-si, Gyeonggi-do. The model results were manually calibrated using the monitoring data of the Woldong reservoir sedimentation rate from 2005 to 2007. It was estimated that annual average of 34.4 tons/year of sediment was discharged from the Woldong reservoir basin. This estimate almost coincided with the monitoring data of the Woldong reservoir during the low flow period but tended to be somewhat underestimated during the high flow period. Although the SWAT model does not fully reflect the erosion process of gully and in-channel, this underestimation is probably due to the spatial connectivity of sediment transport and the storage and reactivation of the sediment being transported. Most of the forested hillslopes with a well-developed organic horizon were evaluated as having a low risk of erosion, while the places with the highest risk of erosion were predicted to be distributed in the logged area with some weeds or shrubs (classified as pasture) with relatively steeper slopes, and in the bare land. The results of this study are expected to be useful in developing strategies for sediment control and reservoir management.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.1066-1080
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• 2024

SMART100 has a containment pressure and radioactivity suppression system (CPRSS) for passive containment cooling system (PCCS). This prevents overheating and over-pressurization of a containment through direct contact condensation in an in-containment refueling water storage tank (IRWST) and wall condensation in a CPRSS heat exchanger (CHX) in an emergency cool-down tank (ECT). The Korea Atomic Energy Research Institute (KAERI) constructed scaled-down test facilities, SISTA1 and SISTA2, for the thermal-hydraulic validation of the SMART100 CPRSS. Three separate effect tests were performed using SISTA1 to confirm the heat removal characteristics of SMART100 CPRSS. When the low mass flux steam with or without non-condensable gas is released into an IRWST, the conditions for mitigation of the chugging phenomenon were identified, and the physical variables were quantified by the 3D reconstruction method. The local behavior of the non-condensable gas was measured after condensation inside heat exchanger using a traverse system. Stratification of non-condensable gas occurred in large tank of the natural circulation loop. SISTA2 was used to simulate a small break loss-of-coolant accident (SBLCOA) transient. Since the test apparatus was a metal tank, compensations of initial heat transfer to the material and effect of heat loss during long-term operation were important for simulating cooling performance of SMART100 CPRSS. The pressure of SMART100 CPRSS was maintained below the design limit for 3 days even under sufficiently conservative conditions of an SBLOCA transient.

• Food Science of Animal Resources
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• v.44 no.3
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• pp.684-698
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• 2024

We investigated Cissus quadrangularis L. powder (C) use as a natural additive to Tteokgalbi, a traditional Korean meat-based dish. Five distinct Tteokgalbi samples were treated: one without any additives (negative control, NC), one with 1.00% C (C1), 2.00% C (C2), 4.00% C (C3), and 0.10% ascorbic acid (positive control, PC). C addition resulted in changes in composition, quality, and sensory attributes. Moisture content decreased with higher C levels; crude protein varied among the groups, with C1 having the highest crude protein levels and C3 the lowest. Crude fat decreased with increasing C concentration, whereas the carbohydrate content increased. The water-holding capacity notably decreased in the C3 group, resulting in increased cooking loss with higher C concentrations. C treatment altered color and texture, reducing CIE L^* and increasing CIE a^* before cooking and increasing CIE L^* and CIE a^* after cooking. CIE b^* decreased before cooking but increased thereafter. C-treated Tteokgalbi was less cohesive, chewy, and brittle compared to the NC. The C treatment increased the total phenolic and flavonoid contents and enhanced radical scavenging capacities. It also affects storage characteristics, lowers pH, and increases 2-thiobarbituric acid reactive substances values. The microbial counts were lower in C2 and C3 after 11 days. These findings suggest the potential use of C as a natural meat additive.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.3
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• pp.275-285
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• 2010

Present state of nationwide marine facilities reported to 12 regional maritime affairs and port offices of MLTM in Korea for two years 2008 and 2009 was analyzed based on region and type of facilities, and national management plan was proposed in this study. As of the end of 2009, 8 types of marine facilities were reported to Yeosu regional maritime affairs and port office, while only 3 types of facilities were reported to Pohang, Daesan and Jeju regional offices, respectively. Oil and noxious liquid substances storage facilities belonged in the type of facility which was reported to all of 12 regional offices, and ranged from 11 facilities reported to Pyeongtaek regional office to the respective 38 facilities to Yeosu and Masan regional offices. In pollutants storage facilities, 4 facilities were reported to Masan regional office, 2 facilities to Donghae and Mokpo regional offices, respectively, 1 facility to Yeosu, Gunsan and Pyeongtaek regional offices, respectively, and none of facilities to the other regional offices. Ship construction, repair and scrap facilities belonged in the type of facility which was reported to all of 12 regional offices, and 45% of the facilities were concentrated in Southeastern Sea of Korea centering around Busan and Masan. In cargo handling facilities, 3 facilities were reported to Busan and Masan regional offices, respectively, 1 facility to Daesan regional office, and none of facilities to the other regional offices. In wastes storage facilities, 5 facilities were reported to Ulsan regional office, 4 facilities to Gunsan regional office, 2 facilities to Incheon regional office, 1 facility to Yeosu regional office, and none of facilities to the other regional offices. 65% of nationwide water intake and drainage facilities were concentrated in the areas of Pohang and Mokpo, and 78% of nationwide fishing spots at play were concentrated in the area of Masan. In other marine facilities, 4 facilities were reported to Donghae regional office, 3 facilities to Masan regional office, 2 facilities to Yeosu and Pyeongtaek regional offices, respectively, 1 facility to Incheon and Ulsan regional offices, respectively, and none of facilities to the other regional offices. In integrated marine science base facilities, 3 facilities were reported to Jeju regional office, 1 facility to Yeosu, Ulsan and Gunsan regional offices, respectively, and none of facilities to the other regional offices. The management based on the circumstances of regional offices, the management based on the characteristics of the type of facilities, the amendment of the relevant rules and regulations, facility owner's full knowledge and observance of the relevant rules and regulations with regard to the relevant type of facilities, and positive management actions from national point of view were proposed for national management plans of marine facilities.

• Korean journal of food and cookery science
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• v.30 no.6
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• pp.663-669
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• 2014

We preprocessed and pickled Deodeok with Doenjang to improve its preservability and to distribute it widely, and we stored Deodeok for 3 weeks at $7^{\circ}C$ and measured its quality. The sample pre-treated with 20% of dextrin retained its early texture better than the samples pre-treated with other methods after 3 weeks of storage (p<0.05). The samples pre-treated with other controls showed propagation of microorganisms; but Doenjang pre-treated with 20% of dextrin or sugar showed less increase in the water content. The microorganisms count in samples pre-treated with other controls was 4.0 log CFU/g after 3 weeks of storage, but the microorganisms count in the sample pre-treated with 20% of dextrin was 2.2 log CFU/g; in other words, the propagation of microorganisms was minimized in the sample pre-treated with 20% of dextrin (p<0.05). In the investigation of the preferences, this D-20 sample showed maximum improvement in color, smell, taste, and other general preferences factors. Thus, the best processing method for the optimal quality maintenance of Deodeok is to sugarize it with 20% of dextrin before pickling with Doenjang. The product prepared using with this process can be preserved for 3 weeks at $37^{\circ}C$; that is, this product is expected to have a refrigerator shelf life of 3 months.

• Food Science and Preservation
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• v.11 no.3
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• pp.325-330
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• 2004

This study was conducted to investigate optimal processing conditions, cooking characteristics, antioxidant activity and packaging method of rice coated with bamboo extract. In sensory evaluation of cooked rice, rice coated with bamboo ethanol extract was higher smell and taste than the other extraction methods, but texture showed no difference. As coating concentration increasing, L, a and b values of coated rice were increased. But L value of coated rice after cooking was decreased. On sensory evaluation of cooked rice, smell and taste were best in 10$\%$ coated with bamboo ethanol extract. Mineral contents of coated rice with bamboo extract were higher than those of uncoated. Water absorption and volume expansion of coated rice were lower than uncoated rice but showed higher toyo value. Hardness, gumminess and chewiness values of cooked rice with coated rice were higher than uncoated rice. Antioxidant activity of coated rice was higher than uncoated rice about twice times. Toyo values and alkali digestive values of coated rice were highest in paper package than the other packaging conditions. The total bacterial counts of rice coated with bamboo extract after cooking was lower than uncoated rice during storage at 25 and 6O$^{\circ}C$.

• Journal of the Korean Wood Science and Technology
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• v.38 no.6
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• pp.587-601
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• 2010

This review attempted to overview characteristics of nanocellulose from various sources, its isolation methods, and properties of nanocellulose-based nanocomposites. Currently, nanocelluloses could be obtained from a variety of cellulose sources, including wood pulp, tunicate, bacterial cellulose etc., and are isolated by various ways such as chemical, physical, or biological methods. The length and width of nanocellulose is in the range of 100~300 nm long and 5~50 nm wide although characteristics of nanocellulose shows a wide variability, depending on sources and isolation method. Nanocellulose is also being used as a reinforcement in the nanocomposites via various methods. Many water soluble polymers were reinforced by the incorporation of nanocellulose, which significantly improves tensile and storage moduli of the nanocomposites. In order to be used for hydrophobic polymers, the surface of nanocellulose was modified. Even though there is a significant progress in the utilization of nanocellulose as a reinforcement of polymers, further research is required to find a niche market of nanocellulose-reinforced nanocomposites. In addition, isolation methods of producing the nanocellulose in a large quantity for commercial applications should be developed to extend the application of nanocellulose-based bio-nanocomposites in future.