• Economic and Environmental Geology
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• v.34 no.4
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• pp.345-354
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• 2001

The effects on arsenic geochemistry of indigenous microorganisms isolated from an area contaminated with high concentration of arsenic were investigated. Arsenite exerted higher inhibitory effects on the microbes' growth than arsenate. During incubation of the microbes in an arsenate-spiked medium over 24 hours, decrease in microbial growth was observed as arsenate content increased. Arsenate of 150 mM or over apparently inhibited cell growth. However, further incubation for up to 4 days in the high arsenate concentration medium resulted in cell growth, implying that the microorganisms adjusted their biochemical functions to detoxify arsenic and maintain growth. Two types of microbes were observed during 20 hours to reduce arsenate to arsenite in solution through a detoxification mechanism. As well, decrease in the total arsenic content occurred over a 4-day incubation with the same microbes in an arsenate-spiked medium. Therefore it is suggested that microorganisms can influence arsenic speciation in natural settings and this may be applied to efficient bioremediation of arsenic-contaminated sites.

• Journal of Digital Convergence
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• v.20 no.1
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• pp.239-247
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• 2022

The purpose of this study was to examine Korean consumers' awareness of Cultured Meat(CM) and influencing factors by gender. On-line survey was conducted from June 9 till June 15, 2021. Analyses of 1,008 respondents whose ages were 20 or older resulted in three points. First, Korean consumers' awareness of CM were lower than the medium in the scale of 1-5, and men reported higher level of awareness than women. Second, the awareness of CM differed by socio-demographic characteristics of participants. The younger, the higher educated, and the students showed higher level of awareness of CM. Third, influencing factors on the awareness of CM differed by gender. In total, gender, age, job, health concern, environmental concern, perceptions of Traditional Meat(TM), and early adopter tendency were significantly associated with the awareness of CM. Among men, age, job, health concern, and early adopter tendency were significant influencing factors on the awareness of CM, where as age, education, health concern, environmental concern, perceptions of TM, and early adopter tendency were so among women. The study results may be used as basic data for developing policies for CM research and consumers.

• Journal of the Korean GEO-environmental Society
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• v.12 no.12
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• pp.31-35
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• 2011

The purpose of this study was to determine optimum condition for the cultivation of Chlorella sp. FC-21, which is a freshwater microalgae, using light emitting diodes (LEDs). Specific growth rate and cell concentration were measured for the reactors at the illumination of different wavelengths of LEDs. Among various types of LEDs, red LEDs were the most effective light source, and also greatest increases of specific growth rate and cell concentrations were obtained when light intensity of red LEDs increased. From this study, we found that red LEDs were the most appropriate light source for the cultivation of Chlorella sp. FC-21.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.6
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• pp.536-544
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• 2012

It is necessary to study the material circulation of coastal ecosystem according to aquacultural activity in order to induce the sustainable production of aquaculture and the fishery environment for the useful use. Hence, it is essential to make an exact assessment for the sedimentation release flux at the sediment-water interface in the aquafarm. Sediment oxygen demand and dissolved inorganic nitrogen release fluxes were compared using in-situ and laboratory incubational examination. Sediment oxygen demands were 116, 34, and $31\;mmol\;O_2\;m^{-2}\;d^{-1}$ (in-situ incubation), 52, 17, and $15\;mmol\;O_2\;m^{-2}\;d^{-1}$ (Core incubation) and dissolved inorganic nitrogen release fluxes were 7.18, 7.98, and $1.78\;mmol\;m^{-2}\;d^{-1}$ (in-situ incubation), 3.33, 3.74, and $1.96\;mmol\;m^{-2}\;d^{-1}$ (Core incubation) at Tongyeong finfish, Yeosu finfish, and Wando abalone cage farms, respectively. Consequently, in-situ incubation results showed two times higher than laboratory examination. We compared the material flux at the sediment-water interface of each farm and the characteristics between two different kinds of material flux examination.

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.299-309
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• 1997

This experiment was conducted to determine the mineral absorption character and develop the optimum composition of nutrient solution for dill(Anethum graveolens L.) in hydroponics. Dill(Anethum graveolens L.) plants were grown in nutrient film technique(NFT) supplied with 1/4, 1/2, and 1 strength of the nutrient solution developed by National Research Station in Japan(HRS). Plants grown in 1/2 strength showed the best growth in plant height, fresh weight, and dry weight compared with those grown in 1/4 or 1 strength. In 1/2 strength solution, pH and EC changed little and proper nutrient contents were observed in the leaves as compared to plant nutrient diagnosis standard. Based on these results, optimum macronutrients were composed by nutrient- water absorption rate(n/w) with 1/2 strength: NO$_2$―N 8.85, NH$_4$―N 0.55, P 2.1, K 6.2, Ca 2.8, and Mg 1.7 me L$^{-1}$ To examine the suitability of the nutrient solution developed(SCU) , dill plants were grown in NFT supplied with two different kinds of solution and concentration. 1/2, 1, 3/2 and 25 of SCU and 1/2S of HRS. Changes of pH and EC were not distinct in 1S, but a significant change of pH was shown in low concentrations-HRS 1/2S and SCU 1/2S. Shoot fresh and dry weight were much higher in the plants grown in SCU IS as compared with HRS 1/2S. There were no significant differences in growth of plants grown in SCU IS, 3/2S, and 25. In addition, nutrient contents in the leaves grown by SCU 1S were in proper levels as compared with plant nutrient diagnosis standard. SCU 1S developed in this experiment was found to be optimum for dill in hydroponics.

• Journal of Bio-Environment Control
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• v.7 no.2
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• pp.123-129
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• 1998

This experiment was conducted to composition of nutrient solution for tore of endive hydroponics, and was compared the nutrient solution developed in the Seoul City University(SCUE) with the conventional solution of Proefstation voor Tuinbouw ender Glas. Proper compositions of nutrient solution for endive hydroponics were NO$_3$-N 15.0, NH$_4$-N 1.0, PO$_4$-P 3.0. K 10.0, Ca 5.0 and Mg 3.5 me.$\ell$$^{-1}$ , respectively SCUE and PTG standard nutrient solution showed slightly better yields among nutrient solutions. The SCUE nutrient solution and the PTG nutrient solution had no difference on growth and yield of endive Plants.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2001.11a
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• pp.176-177
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• 2001

분화용 베고니아 유묘기의 양분흡수 특성을 구명하기 위하여 광강도와 배양액 농도 처리하에 실험을 진행하였다. 엽면적은 광에 의한 차이는 크게 나타나지 않았고 양액의 농도는 EC가 1.0 dSㆍm$^{-1}$처와 1.5 dSㆍm$^{-1}$에서 0.5 dSㆍm$^{-1}$보다 높게 나타났다. 초장은 광강도가 가장 낮은 처리구에서 길었고 약 38%와 60% 차광율 처리사이에는 큰 차이가 없었다. 또한 배양액의 농도에 따라서는 EC가 1.5 dSㆍm$^{-1}$인 처리구에서 EC가 1.0 dSㆍm$^{-1}$과 0.5 dSㆍm$^{-1}$인 처리구보다 초장이 길었다. 엽의 생체중도 처리에 따라 유의적인 차이가 나타났다. 광강도가 가장 낮은 처리구에서 생체중이 가장 높았으나 엽의 건물중은 처리간 차이가 나타나지 않았다. 배양액의 농도처리에 있어서 EC가 1.0 dSㆍm$^{-1}$과 1.5 dSㆍm$^{-1}$인 처리구에서 EC가 0.5 dSㆍm$^{-1}$인 처리구보다 엽의 생체중이 높게 나타났다. 그러나 배양액의 농도는 엽의 건물중에 영향을 주지 않았다. 줄기의 생체중과 건물중은 처리간 차이가 크게 나타나지 않았다. 다량원소의 흡수율을 조사한 결과 주로 배양액의 농도가 증가함에 따라 양분의 흡수율이 증가한다는 것을 알 수 있었다. 또한 광강도의 차이에 따라서 양분의 흡수율이 영향을 받는다는 것을 알 수 있었다. 광강도가 매우 낮은 처리구에서 양액의 흡수는 적었지만 높은 양분흡수율을 보였고 이러한 특성은 각 이온의 종류에 따라 약간의 차이를 보였다.

• Korean Journal of Ecology and Environment
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• v.33 no.1 s.89
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• pp.1-8
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• 2000

Four cyclopoids were tested for laboratory culture. Among these animals, only Eucyclops serrulatus was successfully cultured in the laboratory. Under the laboratory culture condition, nine kinds of diets were tested for the suitability of nauplius development. Development and reproduction of E. serrulatus were also investigated. Chlamydomonas reinhardii was the only one which could induce complete development from nauplii to adults. It was found that E. serrulatus had relatively short generation time, could produce lots of progenies, and could be handled easily, allowing to obtain many individuals during a short period. With these characteristics, this species may be a candidate for a good test organism for evaluating freshwater pollution.

• Environmental engineer
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• s.68
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• pp.4-10
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• 1992

• Environmental engineer
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• v.18 s.190
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• pp.63-67
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• 2002