• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.177-177
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• 2023

• Korean Journal of Environmental Agriculture
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• v.41 no.4
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• pp.282-287
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• 2022

BACKGROUND: Green algae (Chlorella spp.) has been widely used as a biofertilizer to improve the crop yield and quality. However, available information is not enough to verify the mechanism of green algae's beneficial impact on strawberry. This study was conducted to investigate the effect of Chlorella fusca CHK005 application on the growth and nutrient status of strawberry plant and fruit characteristics. METHODS AND RESULTS: A total of 800 seedlings of strawberry variety 'Kuemsil' were planted. Once a week, C. fusca culture solution (1.0 × 10⁷ cells mL^-1) was applied into soil via irrigation in four different concentrations: no application (control), 1/1000 times (× 0.5), 1/500 times (× 1), and 1/250 times (× 2). Result showed that growth of strawberry plant was enhanced by Chlorella application and the highest impact on fresh weight (FW) and chlorophyll content of the plants were observed in × 2 treatment, followed by × 1, × 0.5, and control treatments. The phosphorus (P) concentration in the plant was significantly higher in × 1 and × 2 treatments compared to control. In case of fruit quality, sugar content (°Brix), hardness, and FW were lowest in control, but these values increased as application levels of Chlorella were higher. Also, P and K contents in the fruits increased with increasing the application levels and significant correlation between P content and oBrix in the fruits was found. CONCLUSION(S): Overall, Chlorella application seemed to improve plant growth and fruit quality by increasing the utilization efficiency of P and K in strawberries.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.142-146
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• 2017

지진해일의 수리특성을 분석하기 위하여 유사한 파형특성을 가진 고립파를 많이 이용하고 있다. 그러나 고립파의 근사파형은 실제 지진해일에 비해 상당히 좁은 파형분포를 가지고 있다. 이에 수치모의에서는 기존의 고립파 근사식을 개량하여 고립파형의 지진해일을 수치적으로 생성하고 있다. 본 연구에서는 지진해일의 파형분포에 따른 월파특성을 수치적으로 조사하기 위하여 개량된 고립파 근사식을 2차원 N-S solver에서 적용하였다. 이것에 기초하여 수치파동수조에 직립호안과 그 배후에는 월파수조를 설치하고, 지진해일 월파량을 측정하였다. 수치해석결과로부터 직립호안 주변의 공간파형과 마루 위의 유속분포로부터 파형분포에 따른 월파현상을 분석할 수 있었다. 또한 기존 고립파 근사이론 대비 개량된 고립파의 체적비에 따른 월파량 변화를 정량적으로 조사하였다. 그 결과 지진해일의 체적비가 증가할수록 월파량이 거의 선형적으로 증가하는 경향을 나타내었다.

• Korean Journal of Environmental Agriculture
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• v.41 no.1
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• pp.41-49
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• 2022

BACKGROUND: The main source of ammonia in soils, South Korea is agricultural emissions (e.g., fertilizer application and livestock manure), with the recent emission inventories reporting them to be approximately 80% of the total emissions. Ammonia as a pollutant is originated largely from agricultural activity and is an important contributor to air quality issues in South Korea. The importance of ammonia in agricultural land is also emerging. In this study, the characteristics of ammonia emission from Chinese cabbage cultivation fields with application rates of urea sere were evaluated. METHODS AND RESULTS: The ammonia emission characteristics were investigated at the different urea application rates (0, 160, 320, and 640 kg ha-1) and the ammonia emission factor in the Chinese cabbage cultivation field was calculated. As application rate of urea application increased, ammonia emissions increased proportionally. In 2020 and 2021, cumulative ammonia emissions with urea 320 kg ha^-1 treatment were 39.3 and 35.2 kg ha^-1, respectively for 2020 and 2021. When urea fertilizer was applied, the ammonia emission factors were 0.1217 and 0.1358 NH₄⁺-N kg N kg^-1 in 2020 and 2021, respectively. CONCLUSION(S): Ammonia emissions increased as application rate of urea increased, and the average ammonia emission factor of the Chinese cabbage cultivation field for two years was 0.129 NH₄⁺-N kg N kg^-1.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.261-266
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• 2023

Interception data pertaining to Coleoptera, Hemiptera, Lepidoptera, Diptera, Thysanoptera, and Hymenoptera collected at the Korean quarantine border were cross-checked with new recorded species in Korea from 2015 to 2022. Overall, 45,084 interceptions belonging to the six orders were detected, and 545 species belonging to the six orders were newly reported in Korea. Of the 545 species, nine species were recorded as being intercepted at the quarantine border. Among the six orders, Coleoptera, Thysanoptera, and Hemiptera showed high numbers of interception; however, Hymenoptera revealed the highest number in new recorded species. These results indicate that recent newly recorded species in Korea are not subject to inspection at Korean borders and that the current quarantine system needs improvement.

• Journal of Powder Materials
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• v.28 no.4
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• pp.317-324
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• 2021

High-strength low-alloy (HSLA) steels show excellent toughness when trace amounts of transition elements are added. In steels, prior austenite grain size (PAGS), which is often determined by the number of added elements, is a critical factor in determining the mechanical properties of the material. In this study, we used two etching methods to measure and compare the PAGS of specimens with bainitic HSLA steels having different Nb contents These two methods were nital etching and picric acid etching. Both methods confirmed that the sample with high Nb content exhibited smaller PAGS than its low Nb counterpart because of Nb's ability to hinder austenite recrystallization at high temperatures. Although both etching approaches are beneficial to PAGS estimation, the picric acid etching method has the advantage of enabling observation of the interface containing Nb precipitate. By contrast, the nital etching method has the advantage of a very short etching time (5 s) in determining the PAGS, with the picric acid etching method being considerably longer (5 h).

• Membrane Journal
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• v.31 no.6
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• pp.456-470
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• 2021

In this study, polyetherimide-based hollow fiber membranes were manufactured using the NIPS (nonsolvent induced phase separation) method. THF, Ethanol, and LiNO₃ were used as additives to control the morphology of the PEI-hollow fiber membranes. Furthermore, for the development of a high hydrogen separation membrane, the spinning conditions were optimized through the characterization of SEM and gas permeance. As a result, as the content of THF increased, the hydrogen/carbon dioxide selectivity increased. However, the permeance decreased due to the trade-off relationship. When ethanol was added, a finger-like structure was shown, and when LiNO₃ was added, a sponge structure was shown. In particular, in the case of a hollow fiber membrane with an optimized PDMS coating layer, the permeance was 40 GPU and the hydrogen/carbon dioxide selectivity was 5.6.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.3
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• pp.284-293
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• 2022

In this study, we aimed to optimize the blending conditions of sunflower oil (A), water (B), and oriental sauce (C) for canned smoked oysters Crassostrea gigas in oriental sauce (SOO). Using response surface methodology (RSM), we found that the optimal independent variables [X₁, A/(B+C); X₂, B/C] based on the salinity (Y₁) amino acid nitrogen content (Y₂), and overall acceptance (Y₃) of high-quality SOO were 48.7% (w/w) for sunflower oil, 25.5% (w/w) for water, and 25.8% (w/w) for oriental sauce. Under optimal conditions, the experimental values of Y₁, Y₂, and Y₃ were 1.68±0.4 g/100 g, 155.4±2.4 mg/100 g, 6.2±0.23 score, respectively, which were not significantly different from the predicted values (P<0.05). The SOO prepared under optimal conditions had a higher overall acceptance than commercial canned smoked oysters. These results suggest that developing canned smoked oysters in oriental sauce can be industrialized, and the product is predicted to be competitive in the global market.

• The Journal of Korean Academic Society of Nursing Education
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• v.28 no.3
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• pp.317-327
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• 2022

Purpose: This study aimed to compare the effects of oral swab and non-swab using cold water gauze on patients' thirst and oral status following nasal surgery under general anesthesia. Methods: A non-equivalent control group was applied. Participants were divided into a control group (n=30) that was treated by cared for with cold water gauze application without oral swab and an experimental group (n=29) that was treated cared for with oral swab using cold water gauze after nasal surgery at the G University Hospital in Korea. Data were collected from May 14, 2020, to April 30, 2021, and analyzed using descriptive statistics, a chi-squared test, independent t-test, Wilcoxon signed-ranks test, and Mann-Whitney test. Results: The results showed no significant differences between the two groups in thirst (U=-0.04, p=.693) and overall oral condition (U=-0.34, p=.813) after the intervention. However, participants' thirst and oral condition were significantly improved in each group after intervention. Conclusions: It was confirmed that both oral care methods reduced thirst and improved oral condition after nasal surgery. These findings indicate the need for intervention for patients' thirst and oral condition after nasal surgery. Furthermore, they show that these oral care protocols can be used as a safe and effective nursing intervention for patients who undergo nasal surgery under general anesthesia.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.4
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• pp.397-407
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• 2022

This study investigated the collagen and texture properties of commonly consumed sliced raw fish species (CC-SRF) [olive flounder (OF), red seabream (RS), Atlantic salmon (AS), coho salmon (CoS) and sockeye salmon (SS)] distributed in Korea as sliced raw fishes. The crude lipid contents of CC-SRF were 5.5% for OF, 6.8% for RS, 18.5% for AS, 16.1% for CoS, and 5.7% for SS. The collagen content and solubility from CC-SRF were 622 mg/100 g and 78.0%, respectively, in OF, 270 mg/100 g and 75.6%, respectively, in RS, 237 mg/100 g and 24.1%, respectively, in AS, 341 mg/100 g and 65.7%, respectively, in CoS, and 246 mg/100 g and 17.9%, respectively, in SS. The texture of CC-SRF was affected by the lipid content, collagen content, acid solubility, hydroxylation, and cross linkage degree. The highest hardness of CC-SRF was obtained from OF, followed by RS, SS, AS and CoS. There was, however, no difference (P>0.05) in hardness between OF and RS and between AS and CoS.