• Biotechnology and Bioprocess Engineering:BBE
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• 제11권4호
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• pp.351-356
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• 2006

This study developed an artificial neural network (ANN) to estimate the growth of microorganisms during a fermentation process. The ANN relies solely on the cumulative consumption of alkali and the buffer capacity, which were measured on-line from the on/off control signal and pH values through automatic pH control. The two input variables were monitored on-line from a series of different batch cultivations and used to train the ANN to estimate biomass. The ANN was refined by optimizing the network structure and by adopting various algorithms for its training. The software estimator successfully generated growth profiles that showed good agreement with the measured biomass of separate batch cultures carried out between at 25 and $35^{\circ}C$.

• ALGAE
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• 제19권2호
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• pp.149-151
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• 2004

Freshwater algae make up a very important portion of the autotrophic component of the aquatic food web. Therefore, the study of freshwater algal structure and biomass is central to aquatic ecosystem studies. Due to variations in cell shape and size for each species (or taxon) and survey site, cell abundance (or cell numbers per chosen volume) often leads to misrepresentation of the true importance of some species because of the great differences in size of various algae. Thus, it is necessary to investigate the freshwater algal species of a site in order to calculate the cell volume. Although direct cell counting, species volume measurement, as well as biomass calculation are time-consuming and requiring specialists in taxonomy.

• 환경생물
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• 제21권4호
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• pp.428-438
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• 2003

Benthic marine algal community of Hakampo in the western coast of Korea was investigated qualitatively and quantitatively. Seasonal assessments of species composition, biomass, dominant species in biomass and vertical distributional pattern were carried out from spring to winter. A total of 121 species was identified; 6 blue-green, 18 green, 16 brown, 81 red algae. In three sites investigated, 96 species were collected at Bunjeomdo, 75 at Maoe, and 57 at Doranggol, respectively. Dermocarpa sp. and Acrochaetium microscopicum were collected for the first time in Korea through this investigation. Dominant species in specific proportions of biomass were Sargassum thunbergii, Gloiopeltis furcata, Corallina spp., Symphyocladia latiuscula and Monostroma nitidum. Seasonal fluctuations of mean biomass were 31.59-427.69 g dry wt$.$$\mu \textrm m^{-2}$ at Bunjeomdo and 20.98-473.48 g dry wt$.$$\mu \textrm m^{-2}$ at Maoe, respectively, which were comparatively high in the western coast of Korea. Vertical distribution in intertidal zones was Gloiopeltis furcata-Gloiopeltis furcata and Corallina spp.-Corallina spp. and Sargassum thunbergii.

• Journal of Plant Biology
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• 제33권4호
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• pp.225-236
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• 1990

Intertidal algal communities of Muchangpo and Maryangri in western coast of Korea were investigated qualitatively and quantitatively. Seasonal assessments of species composition, biomass, dominant species in biomass and vertical distributional pattern were conducted from July 1986 to April 1988. Ninety-nine species of marine algae (13 Cyanophyta, 12 Chlorophyta, 24 Phaeophyta and 50 Rhodophyta) were observed, of which 90 (13 Cyanophyta, 11 Chlorophyta, 23 Phaeophyta and 43 Rhodophyta) were from Muchangpo and 83 (10 Cyanophyta, 11 Chlorophyta, 21 Phaeophyta and 41 Rhodophyta) were from Maryangri, respectively. Ordination by detrended correspondence analysis based on the floristic data from nine localities indicated that, on the whole, marine algal distribution in western coast of Korea might be divided into two regions, i.e. the north and the south, being separated at the Taean Peninsula, the mid-western coast. Seasonal fluctuations of mean biomass were 44.55-201.19g-dry wt/$m^2$ at Muchangpo and 19.59-134.76g-dry wt/$m^2$ at Maryangri. Important species determined by the specific proportion of biomass were Sargassum thunbergii, Pelvetia siliquosa and Corallina pilulifera at Muchangpo, and Sargassum thunbergii and Corallina pilulifera at Maryangri.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.29-34
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• 2004

Biosorption technology is recognized as an economically feasible alternative for the removal and/or recovery of metal ions from industrial wastewater sources. However, the structure of biosorbents is quite complex when compared with synthetic ion-exchange resins, which makes it difficult to quantify the ion-binding sites. Accordingly, this report describes a well-defined method to characterize the pK values and numbers of biomass functional groups from potentiometric titration data. When the proposed method was applied to Sargassum polycystum biomass as a model biosorbent, it was found that the biomass contained three types of functional groups. In addition, the carboxyl group (pK=$3.7{\pm}0.09$) was found to be the major binding sites ($2.57{\pm}0.06 mmol/g$) for positively-charged heavy-metal ions.

• 한국환경과학회지
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• 제11권4호
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• pp.327-332
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• 2002

Optical microscope, SEM (Scanning Electron Microscopy) and fluorescent microscope were used for qualitative and morphological studies of the attached biomass on PE (polyethylene) substratum under anaerobic condition. It was shown by the observation of optical microscope that the initial attachment of biomass began in crevices of the surface of PE. The shape and structure of the attached biofilm could be observed by SEM photographs, but species of bacteria were and methanogens were not classified. A large number of methanogenic bacteria were identified on the surface of PE substratum by fluorescence under 480nm of radiation. It was estimated that methanogenic bacteria was also related to initial attachment of biomass under anaerobic condition.

• 한국수산과학회지
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• 제47권3호
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• pp.274-282
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• 2014

We examined seasonal variation in the structure of marine macroalgal communities at five sites around the Byeonsan Peninsula, Korea, from January to October 2011. Sixty eight species were identified, including 11 green, 17 brown and 40 red algae. Species richness was highest at Gyeokpo (51 species) followed by Sambal (47), Gosapo (34), Byeonsan (33), and Habgoo (18). Seaweed biomass ranged from 12.98 to 145.33 g dry $wt/m^2$, with maximum and minimum biomasses at Gyeokpo and Habgoo, respectively. Sargassum thunbergii was the representative alga species occupying 47.89% of the total biomass. The dominant seaweeds were S. thunbergii, Corallina pilulifera, Ulva spp, Gracilaria vermiculophylla, and Carpopeltis affinis. No distinctive vertical distribution of seaweeds was found because S. thunbergii, Ulva spp, and G. vermiculophylla were all distributed from high to low shore. Community indices were as follows: dominance index (DI), 0.44-0.61; richness index (R), 6.27-10.35; evenness index (J'), 0.38-0.59; and diversity index (H'), 1.48-1.71. Gyeokpo had the most biomass and highest species richness, and the lowest percentage of Ulva species. However, species richness declined at Gyeokpo, from 78 to 51 species within 10 years, implying that eutrophication and sedimentation from Mankyeong and Dongjin rivers have reduced the stability of seaweed communities.

• Korean Chemical Engineering Research
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• 제54권4호
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• pp.519-526
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• 2016

Biomass derived jet fuel is proven as a potential alternative for the currently used fossil oriented energy. The efficient production of jet fuel precursor with special molecular structure is prerequisite in producing biomass derived jet fuel. We synthesized a new jet fuel precursor containing branched $C_{15}$ framework by aldol condensation of furfural (FA) and ethyl levulinate (EL), where the latter of two could be easily produced from lignocellulose by acid catalyzed processes. The highest yield of 56% for target jet fuel precursor could be obtained at the optimal reaction condition (molar ratio of FA/EL of 2, 323 K, 50 min) by using KOH as catalyst. The chemical structure of $C_{15}$ precursor was specified as (3E, 5E)-6-(furan-2-yl)-3-(furan-2-ylmethylene)-4-oxohex-5-enoic acid ($F_2E$). For stabilization, this yellowish solid precursor was hydrogenated at low temperature to obtain C=C bonds saturated product, and the chemical structure was proposed as 4-oxo-6-(tetrahydrofuran-2-yl)-3-(tetrahydrofuran-2-yl)-methyl hexanoic acid ($H-F_2E$). The successful synthesis of the new jet fuel precursors showed the significance that branched jet fuel could be potentially produced from biomass derived FA and EL via fewer steps.

• 환경생물
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• 제39권1호
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• pp.81-87
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• 2021

2008년 4월부터 2009년 3월까지 1년간 우리나라 서남해안 함평만의 도리포에서는 조간대의 해조류 식물 군집과 가입리에서는 식용 해조류 가시파래의 월별 변동성을 매월 조사하였다. 조사된 해조류는 총 22종이었으며, 녹조류 5종, 갈조류 4종 그리고 홍조류 13종이었다. 함평만 도리포 암반 조간대에서 연간 우점하는 해조류는 구멍갈파래였고, 준 우점종은 잎파래와 애기가시덤불이었다. 조간대 상부에서 하부에 이르는 수직분포는 잎파래 - 애기가시덤불 - 구멍갈파래 - 지충이었다. 가시파래의 생물량은 6월에 최대를 보였고 11월에 최소를 보였으며, 2.4-98.2 g dry wt. m^-2 범위를 나타냈다. 가시파래의 생물량은 수온과 연관이 있어 보이지만 영양염류 및 빛의 강도 같은 기타 환경요인과의 관계는 추후 지속적인 연구가 요구된다.

• 수산해양교육연구
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• 제27권1호
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• pp.273-283
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• 2015

This study was carried out to examine the species composition and community structure of benthic marine algae at the subtidal zones of Daepo, Wolpyeong, Wimi and Jigwido in south Jeju, Korea from March to December 2009. Total 87 species including 14 green algae, 23 brown algae, and 50 red algae were collected and identified. Among these species, 9 species were found throughout the year. The dominant species which contributed significantly to the total biomass were Ecklonia cava, Undaria pinnatifida, Peyssonnelia capensis, Cladophora wrightiana, Sargassum serratifolium, Grateloupia angusta, Codium coactum, Plocamium cartilagineum, and Sargassum macrocarpum. The average seaweed biomass was 7,578.2 g wet weight $m^{-2}$ and maximum biomass was recorded seasonally in spring ($9,627.6g\;m^{-2}$), while minimum was recorded in autumn ($5,963.0g\;m^{-2}$), by sites maximum biomass Jigwido ($12,889.9g\;m^{-2}$), while minimum was recorded in Daepo ($5,403.8g\;m^{-2}$). The seasonal and regional flora were investigated as six functional groups. A coarsely branched form was the most dominant functional group constituting from 42.9~52.8% of the total flora. Ecological state group (ESG) II, as an opportunistic species, including sheet form, filamentous form, and coarsely branched form, consisted of 31~59 species, constituting 77.5~84.9%.