• Journal of Korea Foresty Energy
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• v.19 no.1
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• pp.1-6
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• 2000

This study was carried out to investigate the growth responses of Pinus densiflora seedlings to enhanced UV-B environment for 16 weeks in the field condition. The seedlings were treated with one of three levels of UV-B dosages - ambient UV-B, ambient + 3.2, and ambient + 5.2 KJ m$^{-2}$day$^{-1}$ and the irradiation was performed at the stage before the germination, the fully expanded cotyledon, and the primary needles grown more than 0.8cm in length of the seedlings, respectively. Enhanced UV-B irradiation reduced the height and the root collar diameter growth, and dry mass production of the seedling, and T/R ratio was increased by the UV-B treatment. Difference in seedling growth was observed by difference in time of the UV-B treatment. Among the seedlings which were treated with ambient - 3.2 KJ m$^{-2}$day$^{-1}$, height and root collar diameter growth was relatively high in the seedling received the UV-B treatment at the stage before the germination. The lowest dry mass production was observed in the seedlings received the UV-B at stage of cotyledon both in two levels of enhanced UV-B treatment. Chlorophyll concentration was reduced by enhanced UV-B irradiation, and chlorophyll a/b ratio was increased by the UV-B treatment.

• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.197-206
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• 2001

The depletion of stratospheric ozone is regarded as a major environmental threat to plant growth and ecosystem. The ozone depletion has caused plants to be exposed to an increased penetration of solar ultraviolet-B (UV-B) radiation in the 280-320 nm wavelength range. Enhanced UV-B radiation may have influence on plants biological functions in many aspects including inhibition of photosynthesis, DNA damage, lipid peroxidation, changes in morphology, phenology, and biomass accumulation. To cope with the damage by UV radiation, plants have evolved to have protective mechanisms, such as photorepair, accumulation of UV-absorbing compounds, leaf thickening and activation of antioxidative enzymes. The objective of this review is to address the effects of enhanced UV-B on plant growth, UV-B action mechanisms and protection and protection mechanisms in plants.

• Korean Journal of Weed Science
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• v.30 no.2
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• pp.135-142
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• 2010

To investigate the effects of ultraviolet(UV-B) on growth and biochemical defense responses of plant, garden balsam (Impatiens balsamina L.) was subjected to enhanced UV-B irradiation [daily dose: 0.02 (No UV-B) and 11.34 (enhanced UV-B) kJ $m^{-2}$ ; $UV-B_{BE}$] for 3 weeks. Enhanced UV-B drastically inhibited leaf area as well as dry weight of garden balsam. The content of malondialdehyde was significantly increased by about 50% after 3 weeks of UV-B irradiation. The ratios of dehydroascorbate/ascorbate and oxidized glutathione/reduced glutathione were also considerably increased by UV-B irradiation. Three major polyamines of garden balsam leaves: putrescine, spermidine and spermine were observed. All polyamine contents were increased with UV-B irradiation. The enzyme (superoxide dismutase, ascorbate peroxidase etc.) activities of garden balsam were increased by the UV-B enhancement. Based on the results, enhanced UV-B caused oxidative stress in garden balsam and biochemical protection responses might be activated to prevent from damaging effects of oxidative stress generated by UV-B irradiation.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.469-476
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• 1999

This study was carried out to investigate the growth and physiological response of shade intolerant and intermediate tree seedlings to enhanced UV-$B_{BE}$(biologically effective UV-B) radiation. The seedlings of Betula platyphylla var. japonica Hara(shade intolerant species) and Fraxinus rhynchophylla Hance(shade intermediate species) were treated with one of the three levels of UV-$B_{BE}$ dosages - ambient UV-$B_{BE}$, ambient+3.2, and ambient+$5.2\;KJ\;m^{-2}day^{-1}$) for 14 weeks in the field condition. Height and root collar diameter growth, leaf area, and biomass production of the seedlings of two species were reduced by enhanced UV-B radiation. Leaf stomatal resistance to water vapor of the F. rhynchophylla seedling was increased by the UV-B increment. The reductions in total chlorophyll and carotenoid were more apparent in the F. rhynchophylla than B. platyphylla seedling. There was no statistically significant changes in the concentration of UV-B absorbing compound($A_{300}$) in the leaves of the two species among the UV-B treatment. However the $A_{300}$ tented to be increased in F. rhynchophylla by enhanced UV-B radiation. These results indicate that the growth and the physiological and biochemical responses between B. platyphylla and F. rhynchophylla were different to enhanced UV-B environment.

• Korean Journal of Agricultural Science
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• v.41 no.4
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• pp.275-281
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• 2014

The ozone depletion has caused plants to be exposed to an increased penetration of solar ultraviolet-B (UV-B) radiation. Enhanced UV-B radiation may have influence on biological functions of plant in many aspects including inhibition of photosynthesis. It is evident that UV-B can potentially impair the performance of all three main component processes of photosynthesis, the photophosphorylation reactions of the thylakoid membrane, the $CO_2$-fixation reactions of the Calvin cycle and stomatal control of $CO_2$ supply. Owing to these depressed reactions, the production and allocation of carbohydrates might be markedly affected, and therefore, the growth and development of plant are distinctly reduced. In this review paper, we provide basic theory and further researches in terms of photosynthesis and carbohydrate synthesis in response to elevated UV-B radiation.

• Korean Journal of Environmental Agriculture
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• v.25 no.1
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• pp.7-13
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• 2006

Plastichouse cultivation for crops and vegetables in the winter has been widely popularized in Korea. In the vinylhouse Ultraviolet B penetration is lower than in the field, and so some problems, as plant overgrowth and outbreak of disease, occurred frequently. The effect of artificial supplement ultraviolet B $(UV-B:280{\sim}320nm)$ radiation on the physiological responses and yield of perilla (perilla frutescens) was investigated UV-B ray was radiated on perilla with the 10th leaf stage at the distance of 90, 120 and 150 cm from the plant canopy for 30 days after planting in the vinylhouse. The production of fresh perilla leaves was high in the order of plastic house, ambient+50% of supplemental UV-B, ambient ambient+100% of supplemental UV-B. Enhanced UV-B radiation affected the intensity of thirty-three proteins in 2-dimensional electrophoretic analysis of proteins and ten proteins out of them seemed to be responsive to UV-B : a protein was, ATP synthase CF1 alpha chain, down regulated and nine proteins (Chlorophyll a/b bindng protein type I, Chlorophyll a/b binding protein type II precursor, Photosystem I P700 chlorophyll a apoprotein A2, DNA recombination and repair protein recF, Galactinol synthase, S-adenosyl-L-methionine, Heat shock protein 21, Calcium-dependent protein kinase(CDPK)-like, Catalase) were up-regulated.

• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.182-188
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• 2011

This research was conducted to evaluate the effect of supplemental light-emitting diode (LED) light on growth characteristics and phytochemical content of pepper (Capsicum annuum L.) seedling using LED blue (470 nm, B), red (660 nm, R), blue + red (BR), far red (740 nm, FR) and UV-B (300 nm) light treatment, and without artificial light. Photon flux of LED light was 49, 16, 40, 5.0 and $0.82{\mu}mol\;m^{-2}s^{-1}$ for B, R, BR, FR, and UV-B light, respectively, during experiment. Supplemental LED light duration was $16hr\;day^{-1}$ and UV-B light duration was 10 min. per day after sunset up to 15 days (12 days after germination) of plants age. In our research, growth characteristics and phytochemical content of pepper seedlings were greatly influenced by supplemental LED light compare to control treatment. Red light increased the number of leaves, number of nodes, leaf width and plant fresh weight by 34%, 27%, 50% and 40%, respectively. Blue light increased the leaf length by 13%, and stem length and length of inter node were increased by 17% and 34%, respectively under grown far red light. After 15 days of light treatments phytochemical concentrations of pepper plants were significantly changed. Blue light enhanced the total anthocyanin and chlorophyll concentration by 6 times and 2 times, respectively. Red light increased the total phenolic compound at least two folds meanwhile far red light reduced the ascorbic acid and antioxidant activity 31% and 66%, respectively compared to control treatment.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.2
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• pp.139-148
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• 2002

Both UV Photolysis and Phtocatalytic Oxidation Processing are an emerging technology for the abatemant of Volatile Organic Compounds (VOCs) in atmospheric -pressure air streams. However, each process has some drawbacks of their own. The former is little known as an application for air pollution treatment, so it has been a rare choice in the field. Therefore we have to do more experiment and study for its application for treatment of VOCs. Although the latter has been used in the industrial fields, it still has a difficulty in decomposing high concentrations of VOCs. To solute these problems, we have been studying simultaneous application of those two technologies. We have studied the effects of background gas composition and gas temperature on the decomposition chemistry. It has shown that concentration of TCE and B.T.X., diameter of reactor, and wavelength of lamp have effects on decomposition efficiency. When using Photolysis Process only, the rates of fractional conversion of each material are found at TCE 79%, Benzene 65%, Toluene 68%, Xylene 76%. In case of Photocatalytic Oxidation Process only, the rates of fractional conversion decreased drastically above 30 ppm. When there two methods were combined, the rates of fractional conversion of each material are enhanced such as TCE 93%, Benzene 75%, Toluene 81%, Xylene 90%. Therefore, we conclude that the combination of Photolysis-Photocatalytic Oxidation process is more efficient than each individual process.

• Bulletin of the Korean Chemical Society
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• v.22 no.2
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• pp.219-227
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• 2001

The silver colloidal effects on the excited-state structure and intramolecular charge transfer (ICT) of p-N,N-dimethylaminobenzoic acid (DMABA) in aqueous cyclodextrin (CD) solutions have been investigated by UV-VIS absorption, steady-state and time-resolved fluorescence, and transient Raman spectroscopy. As the concentration of silver colloids increases, the ratio of the ICT emission to the normal emission (Ia /Ib) of DMABA in the aqueous $\alpha-CD$ solutions are greatly decreased while the Ia /Ib values in the aqueous B-CD solutions are significantly enhanced. It is also noteworthy that the ICT emission maxima are red-shifted by 15-40 nm upon addition of silver colloids, implying that DMABA encapsulated in $\alpha-CD$ or B-CD cavity is exposed to more polar environment. The transient resonance Raman spectra of DMABA in silver colloidal solutions demonstrate that DMABA in the excited-state is desorbed from silver colloidal surfaces as demonstrated by the disappearance of νs (CO2-)(1380 cm-1 ) with appearance of ν(C-OH)(1280 cm -1) band, respectively. Thus, in the aqueous B-CD solutions the carboxylic acid group of DMABA in the excited-state can be readily hydrogen-bonded with the secondary hydroxyl group of B-CD while in aqueous and $\alpha-CD$ solutions the carboxylic acid group of DMABA has the hydrogen-bonding interaction with water. Consequently, in the aqueous B-CD solutions the enhancement of the Ia /Ia value arises from the intermolecular hydrogen-bonding interaction between DMABA and the secondary hydroxyl group of B-CD as well as the lower polarity of the rim of the B-CD cavity compared to bulk water. This is also supported by the increase of the association constant for DMABA/ B-CD complex in the presence of silver colloids.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.469-471
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• 2015

How galaxies are affected by their neighboring galaxies during galaxy-galaxy interactions is a long-standing question. We investigate the role of neighbors in galaxy pairs based on the SDSS data release 7 and the KIAS value-added galaxy catalog. Three groups of galaxies are identified: (a) galaxies with an early-type neighbor, (b) with a late-type neighbor, and (c) isolated ones with no neighbor. We compare their UV + optical colors and $H{\alpha}$ emission as indicators of the recent star-formation rate (SFR). Given that galaxies show systematic differences in SFR as functions of morphology, luminosity, and large-scale environments, we construct a control sample in which the galaxies have the same conditions (in terms of morphology, luminosity, and large-scale environment) except for the neighbor's properties (i.e., morphology, mass, and distance). The results are as follows. (1) Galaxies with a late-type companion demonstrate more enhanced SFR than those with an early-type companion. (2) Galaxies with an early-type neighbor show NUV- and u-band derived SFRs that are even lower than that of isolated galaxies, while they have similar or slightly higher $H{\alpha}$-based SFR compared to isolated ones.