• The Korean Journal of Food And Nutrition
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• v.36 no.4
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• pp.209-221
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• 2023

This study aimed to provide fundamental data that could guide high school students' night eating behavior by investigating habits of their night eating consumption during COVID-19 pandemic (From 2021/5/13 to 5/20). Association between their eating habits and the Nutrition Quotient for Korean Adolescents (NQ-A) were also explored. This study included a total of 604 students, among whom 441 students were identified as night eating consumers. Among all subjects, 30.5% consumed night eating 3~4 times a week, 27.3% consumed 1-2 times a week, and 27.0% did not consume any night eating at all. The high-night eating group had a higher score of total NQ-A than the non-night eating group for both male (p<0.05) and female (p<0.001) students. This was because male students in the high-night eating group reported significantly higher rates of daily dinner consumption compared to non-night eating group. Furthermore, both male (p<0.05) and female (p<0.001) students showed a significant increase in 'Moderation'. 'Diversity' was also significantly increased in female studies (p<0.05) as subcategories of dietary habits according to night eating frequency. These findings highlight the need for practical research to develop nutritional guidelines for night eating that reflect preferences of students while providing adequate nutritional habits.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.149-149
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• 2023

미세플라스틱은 입자크기가 5 mm 이하인 플라스틱으로 정의되며, 수계로 유입된 미세플라스틱은 내분비계 교란물질로 작용하여 생태계에 환경독성을 유발하고 오염물질을 흡착·운반할 수 있는 독성 물질의 매개체로서 미세플라스틱의 위해성에 대한 우려가 증가하고 있다. 본 연구는 수용액에서 다양한 미세플라스틱의 납(Pb) 흡착특성을 평가하고 미세플라스틱의 비표면적에 따른 흡착 효과를 비교하고자 하였다. 플라스틱 종류 중 HDPE (High-density Polyethylene)와 PVC (Polyvinyl Chloride)를 각각 세 가지 크기(Group 1: 2.5 mm - 1.0 mm, Group 2: 1.0 mm - 0.3 mm, Group 3: < 0.3 mm)로 제조하여 분류하였으며, 미세플라스틱 입자크기의 비표면적은 BET(Brunauer, Emmett, Teller)분석을 통하여 측정하였다. 담수환경 조성을 위해 pH 7로 조절한 Pb 용액의 농도(0, 0.5, 1, 5, 10, 30 mg/L)별 흡착실험을 수행하였으며 실험결과를 3가지 흡착등온식(Langmuir, Freundlich, Sips 모델)을 사용하여 미세플라스틱에서 Pb 흡착 거동을 나타내었다. BET 분석 측정결과, PVC의 경우 Group 3 > Group 2 > Group 1 순으로 PVC의 입자크기가 작을수록 비표면적이 크게 나타났으며, HDPE 비표면적 또한 비슷한 경향을 보였다. HDPE와 PVC에서 Pb의 흡착은 Langmuir 모델(R² > 0.97)과 Freundlich 모델(R² > 0.82)보다 Sips 모델(R² > 0.98)이 흡착 거동을 설명하기에 가장 적합하였다. 최대흡착능(Q_m) 상수는 입자크기가 작아질수록 흡착능이 높아지는 추세를 보였으며, 흡착세기(K_F)와 흡착강도(n^-1)는 각 플라스틱의 Group 3(HDPE K_F = 0.028, PVC K_F = 0.032; HDPE n^-1 = 0.225, PVC n^-1 = 0.547)에서 가장 높게 나타났다. 본 연구를 통해 HDPE와 PVC에서 Pb의 흡착특성은 Sips모델로 설명이 가능했으며, 이에 따라 Pb 흡착과정에 복수의 흡착메커니즘이 작용하고 있음을 유추해볼 수 있었다. 미세플라스틱의 입자크기와 비표면적이 Pb 흡착량에 영향을 미치는 것을 알 수 있었으며, 미세플라스틱이 중금속을 흡착하여 생물체 내로 전이시킬 수 있는 매개체 역할의 가능성을 확인하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.223-223
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• 2023

토양수분은 지표면과 지하 영역 사이에 존재하는 수분 및 열에너지의 분배를 제어하거나, 토양 영양분, 식물 성장 및 미생물 활동과 같은 다양한 환경 과정에 영향을 미치는 핵심 구성요소이다. 토양수분은 생태수문학 및 생지화학적 역학, 저수지 관리, 가뭄 및 홍수의 경고, 토양 수분 변화에 따른 작물 수확량 등을 이해하는 데 매우 중요한 역할을 한다. 따라서, 토양 수분의 정확한 측정은 필수적이며, 이러한 필요성에 따라 중력 측정법, 장력 측정법, 전기 저항법 및 시간-주파수 영역반사측정법 등의 다양한 측정 방법들이 다년간 개발되어 사용되었다. 다만, 앞선 방법들은 철저한 실험을 통해 높은 정확성을 확보하였지만, 토양 교란이 발생하는 단점이 존재하며 실험 현장 토양의 물리적, 생물학적, 그리고 화학적 특성의 보존은 매우 어려운 한계점을 가지고 있다. 따라서, 이러한 단점을 극복하기 위해, 본 연구에서는 레일리파를 이용한 비접촉식 비교란 토양수분 센서 개발을 목표로 한다. 모래, 실트, 점토와 같은 세 가지 특징적인 토양 유형에 따른 파동을 측정하고, 측정된 파동으로부터 토양 수분을 추정하기 위해 기존에 개발된 시간-주파수 방법을 활용하여 토양수분을 함께 측정하였다. 비접촉 파동신호를 토양수분으로 변환하기 위하여, fully convolutional network을 개발하였다. 개발한 모델의 결과 검증은 RMSE(Root Mean Square Error)를 활용하여 검증하였으며, 모래, 실트, 점토에서 각각 0.0131, 0.0021, 0.0034 m³ m^-3으로 상대적으로 높은 정확성을 보였다. 즉, 본 연구에서 제시한 누출 레일리파를 사용한 비교란-비접촉 토양수분 측정 방법으로, 토양을 교란하지 않고 토양수분을 측정 할 수 있는 높은 가능성을 제시하였다.

• Journal of Practical Agriculture & Fisheries Research
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• v.10 no.1
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• pp.59-65
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• 2008

Angelica gigas belongs to samphire and perennial plant. It is a well-known oriental medicinal plant for the treatment of gynecological disease. This study was conducted to determine the possibility of development of fermented beverage extracted from sugar-treated leaves and roos of Angelica gigas. We analyzed nutrition components and did experiment on mice to find out pharmaceutical effects. In an experiment on mice, we administered to mice various concentration of diluted angelica solution with water as 1%, 10% and 20% for 1 week. As a result, the angelica effected on inhibiting cohesion of blood platelet and seemed to be helpful to the blood circulatory system. However, the 20% of angelica did not influence prothrombin time, but activated partial thromboplastin time and thrombin time.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.187-194
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• 2016

The purpose of this study was to analyze temperature distribution characteristics using a model swine housing for temperature sensor adjustable positioning and developed a sensor and controller embedded exhaust fans utilizing ICT fusion technology for windowless swine housing. Temperature measured by the sensor attached on the exhaust fan was also determined that there is no problem, the temperature is located in the upper fan given the measured errors shown in the 1℃ temperature difference between the lower temperature than the other positions in the model swine housing. The performance of the exhaust fan at maximum output was found to be 1920rpm, air flow rate 125㎥/min. When the open area ratio of 70% one proper air volume of the exhaust fan was found to be 75㎥/min, 60pa. Maximum efficiency in all of the output of the exhaust fan is exhibited at about 70% open area ratio of the damper. The number of revolution of the exhaust fan was 1920rpm when the output was a maximum of 100%. AC output phase of the pulse duty ratio change of the controller was shown to change without delay. It was determined that the instant fan speed control is possible.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.342-350
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• 2021

This study was conducted to investigate the effect of time of hand-thinning on vegetative growth, bitter pit incidence, fruit quality, and return bloom in 'Gamhong'/M.9 apple trees. The time of hand-thinning were 3, 5, 7 and 9 weeks after full bloom, and the primary thinning (leaving only the king fruit on cluster) and secondary thinning (adjusting crop load) were conducted at the same time. The time of hand-thinning was correlated to the vegetative growth, average fruit wight, yield, soluble solids content, bitter pit incidence, and return bloom, negatively, and to the yield of middle grade fruits (fruit weight was 250-299g and none pit on fruit surface) per tree, calcium contents of leaves, and fruit red color, positively. There was no significant effect of time of hand-thinning on fruit firmness, titratable acidity, and total incomes per tree. In conclusion, if the time of hand-thinning of 'Gamhong'/M.9 apple tree was completed at 9 weeks after full bloom, it could produce about 300g of high-quality fruit without bitter pit.

• Journal of Life Science
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• v.31 no.7
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• pp.641-653
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• 2021

The purpose of this study was to confirm the antifungal activity, plant growth-promoting activity, and mineral solubilizing activity of 18 types of bacteria isolated purely from rhizosphere soil. The potential of isolates of the genus Bacillus and Pseudomonas as biocontrol agents was confirmed through the antifungal activity of these isolates. This activity has been determined to be due to various hydrolytic enzymes on the cell wall of plant pathogenic fungi and the production of siderophores in isolates. In addition, most of the isolates have been found to have aminocyclopropane-1-carboxylate deaminase production activity, indole-3-acetic acid production activity, and nitrogen fixation activity. These characteristics are believed to have a positive effect on root development, growth, and the productivity of crops via a reduction in the concentration of ethylene under conditions of environmental stress, to which plants are commonly exposed. In addition, on testing for the solubilizing activity of the isolates for phosphoric acid, silicon, calcium carbonate, and zinc, some isolates were found to have mineral solubilizing activities. Inoculation of these isolates during plant growth is expected to assist plant growth by converting nutrients necessary for growth into usable forms that can be absorbed by plants. The 18 isolated strains can be used as biocontrol agents due to their antifungal activity, plant growthpromoting activity, and mineral solubilizing activity.

• Journal of Life Science
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• v.29 no.3
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• pp.376-381
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• 2019

To construct useful yeast strain for bioethanol production, we improved yeast harboring various phenotypes by using yeast protoplast fusion method. In this study, S. cerevisiae BYK-F11 strain which have ethanol tolerance, thermotolerance and ${\beta}-glucanase$ activity and P. $stipitis{\Delta}ura$ strain which has xylose metabolism pathway were fused by genome shuffling. P. $stipitis{\Delta}ura$ strain was constructed for protoplast fusion by URA3 gene disruption, resulting in uracil auxotroph. By protoplast fusion, several fused cells were selected and BYKPS-F8 strain (fused cell) showing both karyotypes from two parent strains (S. cerevisiae BYK-F11 and P. $stipitis{\Delta}ura$ strain) among 22 fused cells was finally selected. Sequentially, various phenotypes such as ${\beta}-glucanase$ activity, xylose utility, ethanol tolerance, thermotolerance and ethanol productivity were analyzed. The BYKPS-F8 strain obtained ${\beta}-glucanase$ activity from BYK-F11 strain and 1.2 fold increased xylose utility from P. $stipitis{\Delta}ura$ strain. Also, the BYKPS-F8 strain showed thermotolerance at $40^{\circ}C$ and increased ethanol tolerance in medium containing 8% ethanol. In this fused cell, 7.5 g/l ethanol from 20 g/l xylose was produced and the multiple phenotypes were stably remained during long term cultivation (260 hr). It was proved that novel biological system (yeast strains) is easily and efficiently bred by protoplast fusion among yeasts having different genus.

• Korean Journal of Ichthyology
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• v.30 no.4
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• pp.232-237
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• 2018

The feeding habits of Beringraja pulchra were studied using 203 specimens collected from February 2017 to March 2018 in the coastal waters of Incheon, Korea. The size of B. pulchra ranged from 31.1 to 77.7 cm in disc width (DW) and the stomachs of 16 specimens were empty. B. pulchra was a carnivore that mainly consumed fishes and shrimps, but also ate various benthic crustaceans and other invertebrates with small amounts. The main prey items in the diets of shrimps and fishes were Crangon hakodatei and Ammodytes personatus, respectively. The proportion of fishes in prey items increased with size-related while that of shrimps decreased. With increasing disc width of B. pulchra, the mean number of preys per stomach (mN/ST) and the mean weight of preys per stomach (mW/ST) were increased.

• Journal of Life Science
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• v.29 no.8
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• pp.916-921
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• 2019

In this study, we constructed a biological system that exhibited thermotolerance, ethanol tolerance, and increased ethanol productivity using a random mutagenesis method. We attempted to isolate a thermotolerant mutant using proofreading-deficient DNA polymerase ${\delta}$ and ${\varepsilon}$ encoded by the pol3 and pol2 genes, respectively, in Saccharomyces cerevisiae. To obtain mutants that could grow at high temperatures ($38^{\circ}C$ and $40^{\circ}C$), random mutagenesis of AMY410 (pol2-4) and AMY126 (pol3-01) strains was induced. The parental strains (AMY410 and AMY126) grew poorly at temperatures higher than $38^{\circ}C$. By stepwise elevation of the incubation temperature, AMY410-Ht (heat tolerance) and AMY126-Ht strains that proliferated at $40^{\circ}C$ were obtained. These strains were further incubated in medium containing 6% and 8% ethanol and then AMY410-HEt (heat and ethanol tolerance) and AMY126-HEt strain with ethanol tolerance at an 8% ethanol concentration was obtained. The AMY126-HEt strain grew even at an ethanol concentration of 10%. Furthermore, following the addition of high concentrations of glucose (5% and 10%), an AMY126-HEt3 strain with increased ethanol productivity was isolated. This strain produced 24.7 g/l of ethanol (95% theoretical conversion yield) from 50 g/l of glucose. The findings demonstrate that a new biological system (yeast strain) showing various phenotypes can be easily and efficiently bred by random mutagenesis of a proofreading- deficient mutant.