• 한국식품영양학회지
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• 제35권6호
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• pp.473-480
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• 2022

This study aimed to develop an optimal processing method for the production of apple-mango jelly for domestic suppliers, by analyzing the quality attributes of the jelly. According to the central composite design, a total of 11 experimental points were designed including the content of apple-mango juice (X₁), and the sugar content (X₂). The responses were analyzed including the color values (CIE Lab and color difference), physicochemical properties (water activity, sweetness, pH, and total acidity), and textural properties (hardness and gel strength). Regression analysis was conducted, except for total acidity, and showed no significant difference for all the experimental points (p<0.05). Quadratic model was derived for all responses with an R square value ranging from 0.8590 to 0.9978. Based on regression model, the appropriate mixing ratio of apple-mango jelly was found to be 31.11% of apple mango juice and 14.65% of sugar. Through this study, the possibility for developing jelly product using apple-mango was confirmed, and it is expected that these findings will contribute to the improvement of the agricultural industry.

• 한국정보통신학회논문지
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• 제27권1호
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• pp.27-33
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• 2023

웰빙과 건강관리에 대한 관심 증가와 미세먼지로 인한 공기질의 악화, 다양한 토양 및 수질 오염으로 인해 친환경 식재료에 대한 요구가 급증하고 있다. 이와 같은 현상의 해결책으로 아쿠아포닉스가 대두되고 있다. 그러나 최적의 생육 환경을 도출하는 기법이 선행되어야 한다. 본 논문에서는 기존 아쿠아포닉스의 특성을 고려하는 지능형 식물 성장 측정 시스템을 설계하고자 한다. 특히, 지능형 아쿠아포닉스 생산관리 모듈 중 고성능의 처리 자원을 갖지 않는 생산 현장에 적합한 시스템 설계에 주안점을 두고, 균일한 생육환경을 제공하는 경우의 학습 데이터 및 판단 시스템을 위한 모듈 구성 방안을 제안하고자 한다.

• Advances in nano research
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• 제12권1호
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• pp.73-79
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• 2022

Due to the extensive use of concrete structures in various applications, the improvement of their strength and quality has become of great importance. A new way of achieving this purpose is to add different types of nanoparticles to concrete admixtures. In this work, a mathematical model has been employed to analyze the vibration of concrete beams reinforced by graphene oxide (GO) nanoparticles. To verify the accuracy of the presented model, an experimental study has been conducted to compare the compressive strengths of these beams. Since GO nanoparticles are not readily dissolved in water, before producing the concrete samples, the GO nanoparticles are dispersed in the mixture by using a shaker, magnetic striker, ultrasonic devices, and finally, by means of a mechanical mixer. The sinusoidal shear deformation beam theory (SSDBT) is employed to model the concrete beams. The Mori-Tanaka model is used to determine the effective properties of the structure, including the agglomeration influences. The motion equations are calculated by applying the energy method and Hamilton's principle. The vibration frequencies of the concrete beam samples are obtained by an analytical method. Three samples containing 0.02% GO nanoparticles are made and their compressive strengths are measured and compared. There is a good agreement between our results and those of the mathematical model and other papers, with a maximum difference of 1.29% between them. The aim of this work is to investigate the effects of nanoparticle volume fraction and agglomeration and the influences of beam length and thickness on the vibration frequency of concrete structures. The results show that by adding the GO nanoparticles, the vibration frequency of the beams is increased.

• 한국식품영양학회지
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• 제34권6호
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• pp.593-603
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• 2021

In this study, Korean Hallabong produced in Jeju Island and coffee were grafted to prepare coffee containing Hallabong extract and the nutritional components were analyzed. As the amount of Hallabong extract increased, the water content and total polyphenol content increased. However, the crude flour, crude protein, and total flavonoid content decreased significantly. The selenium content per 100 g was 91.28 mg in the 1% Hallabong group, and the iron content was 6.84 mg in the 3% Hallabong group. As the content of Hallabong extract in coffee increased, the L-value (brightness) and b-value (yellowness) increased, but the a-value (redness) showed a tendency to decrease. In the case of DPPH(2,2-Diphenyl-1-picrylhydrazyl) radical scavenging activity, the group containing 9% of Hallabong extract showed the highest value at 47.20 μmol/g of TEAC. In particular, the ABTS(2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonate)) and DPPH radical scavenging activity were significantly increased from coffee powder containing 6% or more of Hallabong extract(p<0.05). The caffeine content decreased as the amount of Hallabong extract added to coffee increased. Therefore, when making powder coffee with Hallabong extract added, it is recommended to set the content of Hallabong extract to 6%.

• Fisheries and Aquatic Sciences
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• 제26권8호
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• pp.470-481
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• 2023

Algal overgrowth in shrimp culture ponds can affect the quality of the aquatic environment, thereby adversely affecting the shrimp and causing economic losses. The objective of this study was to evaluate the variation in phytoplankton composition in intensive shrimp ponds in Bac Lieu province, Vietnam. Phytoplankton samples were collected in three black tiger shrimp (Penaeus monodon) ponds and three whiteleg shrimp (Litopenaeus vannamei) ponds. The collected data were analyzed using SPSS and canonical correlation analysis softwares. In total, 75 species of phytoplankton were recorded in black tiger shrimp ponds and 64 species in whiteleg shrimp ponds. Diatoms had the highest species diversity with 29-30 species (39%-47%), followed by green algae with 9-19 species (14%-25%); species numbers of other phyla varied from 5-12 (8%-16%). The total number of phytoplankton species throughout the study varied from 34-50 species. Algal density was relatively high and ranged from 497,091-2,229,500 ind./L and 1,301,134-2,237,758 ind./L in black tiger shrimp and whiteleg shrimp ponds, respectively. The diatom density tended to increase during the final stage of the production cycle in black tiger shrimp ponds. Blue-green algae and dinoflagellates also increased in abundance at the end of the cycle, which can affect shrimp growth. Diatoms were significantly positively correlated with pH, salinity, total ammonia nitrogen, and nitrate (NO₃^-) concentrations (p < 0.05). Blue-green algae and dinoflagellates were positively correlated with salinity, phosphate (PO₄^3-), and NO₃^-. Algal species diversity was lower in the whiteleg shrimp ponds than in the black tiger shrimp ponds. Several dominant algal genera were recorded in the shrimp ponds, including Nannochloropsis, Gyrosigma, Chaetoceros, Alexandrium, and Microcystis. The results of this study provide basic data for further investigations, and they contribute to the management of algae in brackish-water shrimp ponds.

• Membrane and Water Treatment
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• 제13권2호
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• pp.85-95
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• 2022

Tetrachloroethylene (PCE) and trichloroethylene (TCE), critical pollutants to human health and groundwater ecosystems, are managed by groundwater quality standards (GQS) in South Korea. However, there are no GQSs for their by-products, such as cis-dichloroethylene (DCE) and vinyl chloride (VC) produced through the dechlorination process of PCE and TCE. Therefore, in this study, we monitored PCE, TCE, cis-DCE, and VC in 111 national groundwater wells for three years (2016 to 2018) to evaluate their distributions, a biological dechlorination possibility, and human risk assessment. The detection frequency of them was 30.2% for PCE, 45.1% for TCE, 43.9% for cis-DCE and 13.4% for VC. The four chlorinated compounds were commonly detected in 21 out of 111 wells. In the results of statistical analysis with 21 wells data, DO and ORP also had a negative correlation with four organic chlorinated compounds, while EC and sulfate has a positive correlation with the compounds. This indicates that the 21 wells were relatively met with suitable environments for a biological dechlorination reaction compared to the other wells. Finally, cis-DCE had a non-carcinogenic risk of 10^-1 and the carcinogenic risk of VC was 10^-6 or higher. Through this study, the distribution status of the four chlorinated compounds in groundwater in South Korea and the necessity of preparing plans to manage cis-DCE and VC were confirmed.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.376-378
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• 2021

세계기상기구가 발표한 2020년 글로벌 기후 보고서에 따르면, 2019년 지구의 평균 온도는 산업화 이전인 1850년에서 1900년사이에 측정된 온도보다 평균 1.1℃ 높게 측정되었다. 평균온도의 변화는 기온 상승이 식물 분포에 미치는 영향과 취약성 분석 논문의 따르면 평균온도의 상승시 식물의 분포되는 지역의 변화가 있다는 것을 알 수 있다. 본 논문에서는 이러한 환경 변화에 대응하기 위해, 아두이노와 센서를 사용하여 간헐흐름식 수경재배 스마트팜을 제작하고, PC와 어플리케이션을 통하여 제어하는 방법을 제안한다. 제작된 수경재배 스마트팜은 농장의 온습도, 양액의 ph농도, 조도, 수질의 정도를 파악하고, 양액의 양과 보충 필요 농도 확인, 조도의 따른 생장 LED 제어, 센서의 상태를 파악하여 농장의 전체적인 관리와, 식물의 모종 옮겨심기 이후의 적절한 환경에서 성장할 수 있도록 제어한다.

• 분석과학
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• 제20권1호
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• pp.78-83
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• 2007

식품 중 발기부전치료 성분 및 유사물질의 분석능력을 평가하기 위하여 실험실간 정도관리를 시도하였다. 평가대상물질은 실데나필, 타다라필, 바데나필, 호모실데나필, 하이드록시호모실데나필, 슈도바데나필 6종이었으며, 참여기관은 식품위생검사를 담당하고 있는 13개 기관이었다. 표준시료는 이중맹검을 위하여 평가대상물질 중 임의의 3종을 함유하도록 조제한 인삼음료 13개이었다. 분석방법은 식품공전의 일반시험법에 제시되어 있는 발기부전치료제 유사물질 시험법에 따라 일정량을 취하여 물에 희석한 후 유기용매로 추출하여 HPLC/UV로 분석하고 LC/MS로 확인하는 방법을 적용하였다. 분석기간은 표준시료를 수령한 날로부터 60일이었다. 검사능력관리규정에 따라 Z-값 및 RSZ를 종합평가한 결과 10기관이 만족한 수준이었다.

• Journal of Dairy Science and Biotechnology
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• 제41권4호
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• pp.203-210
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• 2023

Bacterial contamination negatively affects the quality, functionality, and safety of dairy products. Adherent populations of bacteria, referred to as biofilms, grow on the surfaces of dairy processing equipment and are the primary cause of dairy contamination. In addition, microorganisms present in the farm environment and dairy factory can contaminate the Clear-In-Place (CIP) line through raw milk transport pipes; therefore, exhaustive management is required. In dairy manufacturing facilities, biofilm formation is controlled using CIP systems that primarily require sodium hydroxide and nitric acid. However, the leakage or incomplete removal of these potently active compounds can be harmful to humans. In the present study, we compared the eradication of Escherichia coli and other bacteria using commercially available combinations of sodium hypochlorite (NaClO) and citric acid, which are recognized by the Korean Ministry of Food and Drug Safety (MFDS) as food disinfectants. When considered in the CIP system of the field manufacturing process, E. coli was not detected (compared to detection before treatment), and other bacteria were detected at 0-32 culture-forming units (CFU)/cm². The residual amount of chlorine ions after CIP treatment was similar to that in tap water, and there was no significant difference in the overall components of the fermented dairy products. Therefore, the NaClO/citric acid CIP system can be safely applied in dairy manufacturing processes.

• 한국표면공학회지
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• 제57권1호
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• pp.22-30
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• 2024

This study reports a direct growth of carbon nanotubes (CNTs) on the surface of LiCoO₂ (LCO) powders to apply as highly efficient cathode materials in lithium-ion batteries (LIB). The CNT synthesis was performed using a thermal chemical vapor deposition apparatus with temperatures from 575 to 625 ℃. Ferritin molecules as growth catalyst of CNTs were mixed in deionized (DI) water with various concentrations from 0.05 to 1.0 mg/mL. Then, the LCO powders was dissolved in the ferritin solution at a ratio of 1g/mL. To obtain catalytic iron nanoparticles on the LCO surface, the LCO-ferritin suspension was dropped in silicon dioxide substrates and calcined under air at 550℃. Subsequently, the direct growth of CNTs on LCO powders was performed using a mixture of acetylene (10 sccm) and hydrogen (100 sccm) for 10 min. The growth behavior was characterized by scanning and transmission electron microscopy, Raman scattering spectroscopy, X-ray diffraction, and thermogravimetric analysis. The optimized condition yielding high structural quality and amount of CNTs was 600 ℃ and 0.5 mg/mL. The obtained materials will be developed as cathode materials in LIB.