• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.511-516
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• 2005

Sorbitan methacrylate was synthesized from sorbitan dehydrated from D-sorbitol using an immobilized lipase. To optimize the enzymatic synthesis of sorbitan methacrylate, response surface methodology was applied to determine the effects of five-level-four-factors and their reciprocal interactions on sorbitan methacrylate biosynthesis. A total of 30 individual experiments were performed, which were designed to study reaction temperature, reaction time, enzyme amount and substrate molar ratio. A statistical model predicted that the highest conversion yield of sorbitan methacrylate was 100%, at the following optimized reaction conditions: a reaction temperature of 43.06 $^{\circ}C$, a reaction time of 164.25 mins., an enzyme amount of 7.47%, and a substrate molar ratio of 3.98:1. Using these optimal factor values under experimental conditions in four independent replicates, the average conversion yield reached 98.7%${\pm}$1.2% and was well within the value predicted by the model.

• ALGAE
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• 제30권2호
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• pp.89-101
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• 2015

Ecklonia cava Kjellman is a common kelp found in shallow subtidal in warm-temperate waters in the northwest Pacific Ocean. This species has shown substantial morphological variation along with subsistence in different locations and local environments. We quantified the magnitude of morphological variation of E. cava from six populations along ~700 km of coastline from Jeju Island to Dokdo in Korea. In addition, we examined genetic distance among the populations using random amplified polymorphic DNA (RAPD) analysis. Most morphological characteristics investigated were significantly different among locations. Multivariate analyses indicated two phenetically distinct groups (nearshore, sheltered vs. offshore, exposed), indicating wave exposure with turbidity are presumably major factors for the separation. With RAPD data, results of Nei's diversity (H) and AMOVA showed considerable variations in within- and between-populations. Pairwise ${\Phi}_{ST}$ and $N_m$ values indicated moderate gene flow between the six locations. Results of Nei's analysis revealed three genetically distinct groups, not consistent with the morphological groupings, indicating that a time gap may exist between morphological and genetic variations. This study also suggests dispersal distance of this kelp may be longer than what is commonly thought and genetic similarity in the populations was largely reflected by the direction of ocean current rather than just geographical distance.

• 한국수산과학회지
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• 제49권2호
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• pp.124-130
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• 2016

To effectively remove salts from Suaeda japonica, extracts, an electrodialysis system was developed. The biological activities of non-desalted (NDS) and desalted S. japonica (DS) extracts were compared. The DS extract exhibited superior polyphenolic (6.26%) and carbohydrate (28.56%) contents. The IC₅₀ values of the DS extract against DPPH radicals and hydrogen peroxide were 0.22 and 0.68 mg/mL, respectively, which was higher than that of the NDS extract. Neither the DS nor the NDS extract was cytotoxic in RAW 264.7 macrophages. Additionally, the DS extract had a higher NO inhibitory effect compared to the NDS extract in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. These data indicate that DS extracts have greater biological activity than do ND extracts, and application of the electrodialysis process may be useful in marine bioresource applications.

• 한국물환경학회지
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• 제30권6호
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• pp.612-621
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• 2014

Physicochemical factors and the phytoplankton communities in the downstream area of Namhan-River were investigated from June 2012 to November 2013. We also assessed water quality using biological water quality indices. Total nitrogen was 2.4 mg/L, total phosphorus was 0.04 mg/L, and biological oxygen demand was 1.1 mg/L. This resulted in a level 2 (Ib, good) water quality rating. A total of 259 phytoplankton taxa were classified, consisting of 26 families, two subfamilies, 64 genera, 222 species, 32 varieties, and five formas. Bacillariophyceae dominated during a1l seasons and at all sites. The dominant species were Aulacoseira granulata, Cyclotella meneghiniana, C. stelligera, Melosira varians, Cocconeis placentula var. lineata, Nitzschia palea, N. amphibia, Cymbella minuta, and Achnanthes convergens. The diatom assemblage index for organic pollution values was level A-D, and TDI was level B-D. P-IBI at most sites was at the M (moderate) level, but TSI was at the E (eutrophic) level. Most indices dropped from upstream to downstream.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.201-202
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• 1998

In this paper we suggested an automated method for detecting and counting rapid eye movement(REM) using EOG during sleep. This method is formulated by two step fuzzy logic. At first step, the velocity and the distance of single channel eye movement are used for the fuzzy input to get the possibility of being REM at each EOG. At second step, the two possibility values of both EOG from the first step and the correlation coefficient of both eye movements are used for the fuzzy logic input, and the output is the final possibility of being Rapid Eye Movement. We applied this algorithm to the normal and narcoleptic sleep data and compared the difference. We found the possibility that the count of REM can be a parameter that has significant physiological meanings.

• 상하수도학회지
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• 제24권1호
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• pp.5-14
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• 2010

A pilot-scale biological aerated filter (BAF) was operated with an anaerobic, anoxic and oxic zone at $23{\pm}1^{\circ}C$. The influent sCOD and total nitrogen concentrations in the feedwater were approximately 250 mg/L and 35 mg N/L, respectively. sCOD removal at optimum hydraulic retention time (HRT) of 3 hours with recirculation rates of 100, 200 and 300% in the column was more than 96%. Total nitrogen removal was consistently above 80% for 4 and 6 hours HRT at 300% recirculation. For 3 hours HRT and 300% recirculation, total nitrogen removal was approximately 79%. Based on fitting results, the kinetic parameter values on nitrification and denitrification show that as recirculation rates increased, the rate of ammonia and nitrate transformation increased. The ammonium loading rates for maximum ammonium removed were 0.15 and 0.19 kg $NH_3$-N/$m^3$-day for 100% and 200% recirculation, respectively. The experimental results demonstrated that the BAF can be operated at an HRT of 3 hours with 200 - 300% recirculation rates with more than 96 % removal of sCOD and ammonium, and at least 75% removal of total nitrogen.

• 한국물환경학회지
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• 제18권2호
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• pp.189-199
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• 2002

Nitrogen, in its various forms, can deplete dissolved oxygen levels in receiving waters, stimulate aquatic growth, exhibit toxicity toward aquatic life and affect the suitability of sewage for reuse. Pilot-scale Rotating Biological Contactor(RBC) experiments were conducted to examine biological nitrification, respectively, of municipal sewage with five different internal recirculation ratios of 0, 1, 2, 3, and 4 using the constant hydraulic loading of $205L/m^2{\cdot}day$. The use of internal recirculation improved nitrification on account of the dilution of biodegradable organic carbon in influent sewage down to 15 mg/L of $SBOD_5$ or less. Ammonium nitrogen of $14.3{\pm}2.4%$ was consumed by cellular assimilation without the occurrence of denitrification. The thickness of biofilm didn't seem effect significantly the nitrification and denitrification. Nitrification with internal recirculation was found to occur using hydraulic loading rate of as high as $205L/m^2{\cdot}day$, which was beyond the generally known values of it.

• ALGAE
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• 제38권4호
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• pp.217-240
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• 2023

Sulfated polysaccharides (SPs) isolated from seaweed have emerged as remarkable bioactive compounds with a wide spectrum of biological activities and have substantial value in the scientific and industrial domains. The current study explores the diverse biological activities of SPs and their relationship with their structures. This aids in an in-depth examination of the multifaceted biological activities of SPs, including anticoagulant, anti-inflammatory, antiviral, antioxidant, and immunomodulatory properties, which underpin their potential health benefits. Furthermore, the current study explores the complicated properties of SPs, with their extraction methodologies and techniques for precise characterization. Elucidation of the commercial significance of SPs derived from brown, red, and green seaweed by highlighting their potential applications has emphasized their importance in human well-being. Further, this review emphasizes the challenges needed to overcome research and industrial innovations for SPs. Collaboration among researchers, industry stakeholders, and regulatory authorities can overcome these challenges and elevate the potential of SPs to revolutionize industries such as pharmaceuticals, cosmeceuticals, food, and biotechnology.

• Journal of Biosystems Engineering
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• 제28권4호
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• pp.343-350
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• 2003

This study was conducted to find out the coefficient relationships between intensity values of image processing and biological/physical parameters of soil in greenhouses. Soil images were obtained by an image processing system consisting of a personal computer and a CCD earners. A software written in Visual C$\^$++/ systematically integrated the functions of image capture, image processing, and image analysis. Image processing data of the soil samples were analyzed by the method of regression analysis. The results are as follows. For detecting soil density of unbroken soil samples, the highest correlation coefficients of 0.82 and 0.84, respectively were obtained fur R-value and S-value among image processing data while it was 0.97 for G-value. Considering the relationship between biological characteristics and image processing data of soil in greenhouse, the correlation was found generally low. For pH of unbroken soil sample, the correlation coefficients were found 0.87, 0.85, and 0.94, respectively with G, I, and H values of image processing data. In the case of bacteria, any correlation was not found with the image processing data For Actinomyctes, they were 0.86 and 0.85, respectively with G-value and B-value of image processing data showing high correlation coefficient compared to the other variables. The correlation coefficient between Fungi and H-value was shown 0.88, the highest among the variables higher than 0.8 while the other variables showed low correlation. For broken soil samples from greenhouse, the relation between biological parameter and image processing data were rarely shown in this study. The results of this study indicated that most of correlation coefficient between the variables were usually lower than 0.01. Accordingly, it was assumed that the soil should be used without broken to fairly estimate biological characteristics using CCD camera.

• 생태와환경
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• 제45권2호
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• pp.252-260
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• 2012

습지의 생태-사회적 가치는 인간사회에 혜택을 준다. 많은 나라들이 습지를 보전하고 보호하기 위해 노력하고 있다. 하지만 많은 습지들은 자연적 교란과 함께 인위적 교란으로 인해 소실되거나 구획화되었다. 구획화된 습지는 경관생태학적 연구의 주 대상이 되는데 이는 습지를 효율적으로 관리하고 보전하는 데 매우 중요하다. 본 연구는 행정구역상 경상남도 습지의 공간-사회적 분포양상을 파악하기 위해서 습지의 분포와 크기, 습지 간의 거리, 습지의 경관학적 형태, 토지이용현황, 공시지가 등을 연구하였다. 경상남도 내에는 146개(3,598.85 ha)의 습지가 분포해 있고 하천습지가 76개(1,955.60 ha), 범람습지가 49개(1,282.28 ha), 산지습지가 21개(1,282.28 ha)이었다. 대부분의 습지들이 크기가 작고(<2 ha) 농경지에 둘러 쌓여 있었다. 많은 습지들이 구획화되어 있고 훼손상태가 심각하지만 하천습지와 농업용 수로를 이용하여 연결할 수 있는 것으로 보인다. 습지의 연결성 확대를 통한 습지서식처의 확장은 습지에 의존하여 서식하는 생물들의 보전에 매우 유의할 것으로 생각된다. 많은 습지들이 현재 농업용수확보를 위한 유지로 이용되고 있고 국유지의 비율이 높아 추후 습지의 훼손과 소실은 국가단위의 대규모 계획공사로 인할 가능성이 높으므로 생태적으로 민감한 행정과 법률의 개발이 습지의 보전과 관리를 위해 중요하다.