• Journal of Korean Society of Forest Science
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• v.95 no.5
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• pp.562-568
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• 2006

This study was conducted to examine the energy content and photosynthetic efficiency of Quercus mongolica stands in Korea. Study sites were located in Mt. Joongwang, Gangwon-do (1,000 m and 800 m above sea level), Mt. Baekwoon, Jeollanam-do (800 m a.s.l.), Mt. Halla, Jeju-do (1,000 m a.s.l.), Mt. Taehwa, Gyeonggi-do (350 m a.s.l.), and Mt. Wolak, Chungcheongbuk-do (300 m a.s.l.). Total energy content and annual energy accumulation in Q. mongolica stands were 2,916-6,435 GJ/ha and 284-441 GJ/ha, respectively. Lower latitude (N.L.) stands of Q. mongolica showed higher energy contents than higher latitude stands, but Quercus stands in Mt. Baekwoon had higher annual energy accumulation than those in Mt. Halla located at a lower latitude. During the growing season, the photosynthetic efficiency of 60 to 70-year-old Q. mongolica stands ranged from 1.19 to 1.34% while that of 35-year-old stands did from 1.87 to 1.95%. There were no significant differences in photosynthetic efficiency among the latitudes because solar radiation was higher in low latitudes.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.203-209
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• 2010

This study was performed to investigate photosynthetic responses of 4 foliage plants in relation to light intensity, carbon dioxide concentration, and media, and to select efficient plants for the indoor environment control based on the results. Four foliage plants used in this study included Syngonium podophyllum, Schefflera arboricola cv. Hong Kong, Dieffenbachia amoena, and Dracaena deremensis cv. Warneckii Compacta. The plants cultivated in two different growth media, peatmoss and hydroball, and subjected to various light intensities (0, 30, 50, 80, 100, 200, 400, and $600\;{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD) and $CO_2$ levels (0, 50, 100, 200, 400, 700, 1000, and $1500\;{\mu}mol{CO_2}{\cdot}mol^{-1}$). As a result of the photosynthetic rate of foliage plants according to change of light intensity and $CO_2$ levels, Schefflera arboricola and Dieffenbachia amoena showed high apparent quantum yield, which stands for the photosynthetic rate under low light intensity, and both plants also recorded higher photosynthetic rate under high $CO_2$ concentration compared to the other two indoor plants. Dracaena deremensis showed the lowest photosynthetic rate under the low light intensity or high $CO_2$ concentration. There were inconsistent results in photosynthetic rate of foliage plants grown in peatmoss or hydroball. Higher photosynthetic rate was observed in Schefflera arboricola with peatmoss rather than hydroball as light and $CO_2$ concentration increased. However, hydroball had a positive effect on Dieffenbachia amoena in terms of photosynthetic rate. In case of Syngonium podophyllum, peatmoss induced higher photosynthetic rate according to increased light intensity, but there was no effect of media on the rate under various $CO_2$ treatements. In contrast, media did not affect to photosynthetic efficiency of Dracaena deremensis subjected to various light intensities and the rate of Dracaena deremensis with peatmoss was a little high when $CO_2$ concentration increased. In conclusion, potential plants for the indoor air pulification and environmental control were Schefflera arboricola and Dieffenbachia amoena because they showed high photosynthetic rate under typical indoor conditions, low light intensity and high $CO_2$ concentration.

• Journal of Photoscience
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• v.7 no.4
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• pp.139-142
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• 2000

To examine applicability of some optical indices from reflectance to estimate photosynthetic light use efficiency, photosynthesis, and narrow band spectral reflectance were simultaneously measured at various intensities of light with mongolian oak leaves. Narrow band of the broad-band NDVI was better than photochemical reflectance index and simple ratio to estimate photosynthetic light use efficiency in this study. Changes in spectral reflectance were detected at several wavelengths (540nm, 690nm, 740nm, and 800nm) associated with physiological status of plant leaves that could be components for new optical indices.

• Journal of environmental and Sanitary engineering
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• v.16 no.3
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• pp.28-33
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• 2001

Photosynthetic bacteria (PSB), strains IP-4 and IP-6-7 were isolated from nature, and were studied for swine wastewater treatment. It was confirmed that these PSB were very effective for the COD treatment. Growth of those PSB were increased to 4.5 fold in organic-acids (acetate, propionate and butyrate) added medium than cultivation in Lascelles basal medium and the amount of bacteriochlorophyll a were increased to 5 folds. The COD removal rate in swine wastewater using PSB, strains IP-4 and IP6-7 were obtained 91% and 85%, respectively.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.2
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• pp.120-122
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• 2007

A $Q_{10}$-producing photosynthetic bacterium was isolated from the silt at Nakdong river. The isolate had 1.55 mg of $Q_{10}$ per gram of dry cell. By the 16s-rDNA sequence analysis, the isolate was found to be Rhodobacter sphaeroids with 100% similarity (Genbank Accession No.=AM696701).

• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.549-552
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• 1997

A purple non-sulfur photosynthetic bacteria which evolved molecular hydrogen efficiently from glucose in the presence of low concentration of NH4+ under light illuminated anaerobic condition was isolated from mud samples in Korea. This bacteria was identified on Rhodobacter sphaeroides KS 56 based on the morphological, cultural and physiological characteristics.

• Ceramist
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• v.21 no.3
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• pp.233-248
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• 2018

Photosynthesis of plant, algae, and certain types of bacteria can convert solar energy to electrons at high efficiency. There have been many research investigations to utilize this mechanism to develop photosynthetic bio-solar energy systems. In this article, the fundamentals of photosynthetic energy conversion mechanism are explained and various approaches are introduced and discussed.

• The Korean Journal of Ecology
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• v.18 no.2
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• pp.265-273
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• 1995

Net photosynthetic rate (Pn) of Quercus mongolica leaves was determined under the controlled O₃concentrations of 0, 20, 30, 40, 50 or 60 ppb at every 10 min for 7 hr. Under the fumigation of the different O₃concentrations the relative net photosynthetic rate (RNPR) of the leaves decreased rapidly until 1 hr and thereafter decreased slowly. At below 20 ppb O₃the decrease of the RNPR was scarce but at above 20 ppb O₃the RNPR was inversely proportional to O₃concentration on a logarithmic curve. The RNPR at 60 ppb O₃, for example, was reduced 30％ less than that without O₃. Under the different O₃concentrations fumigated for the short period of time the Pn dependent upon PPFD was depicted as saturation equation and Pn dependent upon temperature as quadratic equation. Results of this study suggest that short-term low O₃of less than 60 ppb concentration may lead to reductions of Pn in Q. mongolica leaves.

• Biomedical Science Letters
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• v.14 no.2
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• pp.91-96
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• 2008

Light Emitting Diode (LED) of 880 nm was used as a function of luminosity in culture of the photosynthetic bacteria including Rhodobacter sp.. An array of 880 run LED was driven with an energy density of $6.0mW/cm^2$. In processing time, we were able to show that the cell growth were gained of significant changes in the pigment and in the dry weight. And we also showed that photosynthetic bacteria had the resonable relativity of optical density to dry weight. LED-880nm is of great significance for the potential use of photo-bioreactor construction.

• Journal of Plant Biology
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• v.34 no.3
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• pp.215-221
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• 1991

Photoxynthetic properties of polyvinylalcohol (PVA)-immobilized chloroplast especially regarded to stability of photosynthetic electron transport and the fluorescence induction pattern were studied. When isolated spinach chloroplasts were immobilized with PVA, it showed good preservation of photosynthetic electron transport activity, especially PS II activity, during storage at -15$^{\circ}C$, 4$^{\circ}C$ and 2$0^{\circ}C$. And immobilized chloroplasts revealed similar thermostability of whole chain electron transport to free chloroplsts. And the absorption peak of red band of chloroplasts showed the blue-shift of 2-4 nm after immobilization. Fv/Fm ratio of chlorophyll fluorescence slightly decreased after immobilization. White light pulse after continuous light do not induced the additional fluorescence rise. This means chlorophyll fluorescence at room temperature reached to Fmax under continuous light in the immobilized chloroplasts. It seems that PVA may be a good candidate for immobilization matrix for the preservation of photosynthetic function of thylakoids and for the continuous use of chloroplast membranes of higher plants for solar energy storage and conversion.