• Journal of Bio-Environment Control
• /
• v.11 no.2
• /
• pp.51-55
• /
• 2002

Green peppers (Capsicum annuum L. cv, Soonjung) were grown under different combinations of $CO_2$ concentration and temperature levels and examined on the effect of elevated $CO_2$ and temeprature on plant growth, carbon and nitrogen concentrations. Plant height was stimulated by elevated $CO_2$ levels at 20.3 and 22.6$^{\circ}C$. Leaf area and fresh weight were remarkedly increased by high $CO_2$ concentration at 22.6$^{\circ}C$. Dry weights of leaf, stem, root, and whole plant were increased as temperature increased at 611 ppm $CO_2$, but those values decreased at 22.6$^{\circ}C$ in 397 ppm $CO_2$ concentration. Elevated $CO_2$ increased plant growth by 1.5 times at 20.5$^{\circ}C$ and 22.6$^{\circ}C$. C/N ratio increased with increasing temperature under elevated $CO_2$ levels.

• Journal of Environmental Policy
• /
• v.5 no.3
• /
• pp.79-103
• /
• 2006

This paper attempts to examine household's willingness to pay (WTP) for piped water quality improvement in Wonju, where the local government are planning to implement a piped water quality improvement program. We apply a contingent valuation (CV) method to obtain at least a preliminary evaluation of the WTP. The CV survey was rigorously designed to comply with the guidelines for best-practiced CV studies. We surveyed a randomly selected sample of 250 households in Wonju and asked respondents questions in person-to-person interviews about how much they would be willing to pay for the program. Respondents overall accepted the contingent market and were willing to contribute a significant amount (1,583 to 2,776 won), on average, per household per month. This willingness varies according to individual characteristics such as sex, education level, and income. The aggregate value of the program in Wonju amounts to approximately 1.99 billion won to 3.49 billion won per year. The household values can be the benefits that ensue from the program and compared with the costs of the program to determine whether the program is economically desirable.

• Journal of the Korean Electrochemical Society
• /
• v.13 no.2
• /
• pp.123-127
• /
• 2010

An assembled-graphite/DSA(Dimensionally Stable Anode) was prepared using graphite powder to increase durability and energy efficiency of redox flow battery and investigated its electrochemical properties in vanadium-based electrolyte. The cyclic voltammetry (CV) was carried out in the voltage range of -0.7V and 1.6V vs. SCE at 5 mV/sec scan rate to analyze vanadium redox reaction. From the CV results, the assembled-graphite/DSA electrode showed a fast couple reaction and good reversibility in 2M $VOSO_4$ + 2.5 M $H_2SO_4$ electrolyte. Therefore, it has been expected that this electrode increases power density as well as energy density of redox flow battery.

• Journal of the Korean Electrochemical Society
• /
• v.8 no.2
• /
• pp.99-105
• /
• 2005

In this study, the $PPy/CLO_4$ and PPy/PVS composite electrodes were prepared at various polymerization potential by incorporating electrolyte anions of different anion size during constant potential polymerization. The reulting Polypyrrole surfaces were inspected by SEM, and their electrochemical Properties were investigated with CV and ac impedance method. The results of electrochemical analysis were suggested that anion for $PPy/CLO_4$ electrode and cation fir PPy/PVS electrode were transferred during redox reaction. As constant potential of polymerization was increased, the charge transfer resistance of $PPy/CLO_4$ and PPy/PVS was decreased and the electric double layer capacitances of $PPy/CLO_4$ was higher than that of PPy/PVS. The change of PPy/PVS surface was relatively smaller than that of $PPy/CLO_4$ according to electropolymerization potential.

• Korean Journal of Environmental Agriculture
• /
• v.30 no.4
• /
• pp.382-389
• /
• 2011

BACKGROUND: Light-emitting diodes (LEDs) with lower electric cost and the specific wavelength have been considering as a novel light source for plant production in greenhouse conditions as well as in a closed culture system. Supplementary lighting for day-length extension was considered as light intensity, light quality, and/or photoperiod control on plant growth and development. Effects of supplementary blue or red LED radiation with lower light intensity on growth of Ageratum (Ageratum houstonianum Mill., cv. Blue Field), African marigold (Tagetes erecta L., cv. Orange Boy), and Salvia (Salvia splendens F. Sello ex Ruem & Schult., cv. Red Vista) were discussed during sunrise and sunset twilight in the experiment. METHODS AND RESULTS: Supplementary lighting by blue and red LEDs for 30 (Treatment B30; R30) or 60 (Treatment B60; R60) min. per day were established in greenhouse conditions. Photosynthetic photon flux for supplementary radiation was kept at $15{\mu}mol\;m^{-2}\;s^{-1}$ on the culture bed. Natural condition without supplementary light was considered as a control. The highest shoot and root dry weights were shown in African marigold exposed by red light for 60 min. per day. Supplementary blue and red lighting regardless of the radiation time significantly stimulated development of lateral branches in African marigold. Stem growth in Ageratum and Salvia seedlings was significantly promoted by red radiation as well as natural light. CONCLUSIONS: Extending of the radiation time at sunrise and sunset twilight using LEDs stimulated reproductive growth of flowering plant species. Different characteristics on growth under supplementary blue or red lighting conditions were also observed in the seedlings during supplementary radiation.

• Toxicological Research
• /
• v.25 no.4
• /
• pp.231-235
• /
• 2009

Trace lead detection for cyclic voltammetry (CV) and square-wave (SW) stripping voltammetry was performed using mercury immobilized onto a carbon nanotube electrode (HNPE). Using the characteristics of mercury and the catalytic carbon nanotube structure, a modified technique, the $0.45{\mu}g/l$ detection limit of lead ion was attained. The developed method can be applied to pond water, fish tissue, plant tissue, and in vivo direct assay.

• Journal of the Korean Chemical Society
• /
• v.58 no.3
• /
• pp.289-296
• /
• 2014

Electrochemical copolymerization of o-chlorophenol (oCP) with o-hydroxyphenol (oHP) was carried out in aqueous $H_2SO_4$ by using cyclic voltammetry (CV) technique. In addition, CV was used to evaluate the differences in electrochemical characteristics of the copolymer in comparison with the corresponding homopolymers, poly(o-chlorophenol) (PoCP) and poly(o-hydroxyphenol) (PoHP). The variation of peak currents with respect to sweep rates was compared between copolymer and homopolymers, PoCP and PoHP, films. Further support for copolymer characterization was obtained by recording UV-visible, IR spectra and elemental analysis. The mechanism of the electrochemical polymerization has been discussed. The monomer reactivity ratios ($r_1$ and $r_2$) were calculated using Fineman-R$\ddot{o}$ss method and was found to be 0.4 and 1.3 repetitivelly and the copolymer structure is a block structure and more rich in oHP units.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.2 no.1
• /
• pp.72-82
• /
• 1999

The objective of this study was to covering of vine the traffic noise barrier and analyse of their growth characteristics. For the purpose of the experiments, chosen were 28 plants. In January 1996 to December 1998, the nursery seedbeds on the Chonju Arboretum in Korea Highway Corporation were seeding and cutting with those species, and a few species were carried out Honam Highway field experiments. The results are summarized as follows ; The germination ratio of seedbed experiments were Wisteria floribunda(88%), Lonicera japonica(86%), Parthenocissus tricuspidata, Paederia scandens(85%), Celastrus orbiculatus(76%), Clematis terniflora var. denticulata(52%), Clematis mandshurica(44%) respectively. The rooting ratio of cutting experiments were Trachelospermum asiaticum var. intermedium(88%), Parthenocissus quinquefolia(87%), Trachelospermum asiaticum var. asiatica(85%), Kadsura japonica(82%), Hedera rhombea(81%), Euonymus fortunei var. radicans(83%), Trachelospermum jasminoides var. pubescens(80%), Lonicera japonica cv. Aureo-reticulata(80%), Trachelospermum asiaticum var. majus(78%), Euonymus radicans cv. Aureo-marginata(66%), in descending order. As a conclusion, this study shows that the traffic noise barrier was effected by Paederia scandens, Lonicera japonica, Parthenocissus quinquefolia, Wisteria floribunda, Parthenocissus tricuspidata in the field experiments and the others were necessary to maintainable management.

• Journal of Ecology and Environment
• /
• v.33 no.4
• /
• pp.307-315
• /
• 2010

Males of the field cricket Teleogryllus emma produce calling songs that are attractive to receptive females. The calling songs of T. emma consist of two components, the long chirp that is composed of up to 12 single pulses, followed by a variable number of short chirps. Based on the analysis of coefficient of variation (CV), temporal characters of the long chirp were less variable than those of the short chirps in male calling songs. To test for phonotactic selectivity of females, we conducted a single-stimulus playback experiment in which five stimuli (standard, long chirp only, long chirp augmented, short chirps only, and short chirps augmented) were used. The standard stimulus included both long and short chirps whose characteristics were derived from the calling songs of field populations. Results of the playback experiment showed that female crickets oriented more frequently toward the stimuli that included the long chirp (standard, long chirp only, and long chirp augmented stimuli) than toward the stimuli lacking the long chirp (short chirps only and short chirps augmented stimuli), indicating that the long chirp in the calling songs was required to elicit positive phonotaxis in the female crickets. The result of CV analysis of the male calling songs and the findings of the female phonotaxis experiment suggested that the long chirp of calling songs may play a role in species recognition in T. emma.

• The Plant Pathology Journal
• /
• v.25 no.2
• /
• pp.113-120
• /
• 2009

Microscopic study of chili pepper (Capsicum annuum L.) infected with Phytophthora capsici, causing Phytophthora blight of chili pepper, was conducted to compare histological and cytological characteristics in the root and stem of susceptible (C. annuum cv. Bugang) and resistant (C. annuum cv. CM334) pepper cultivars. The susceptible pepper roots and stems were extensively penetrated and invaded by the pathogen initially into epidermal cells and later cortical and vascular cells. Host cell walls adjacent to and invaded by the infecting hyphae were partially dissolved and structurally loosened with fine fibrillar materials probably by cell wall-degrading enzymes of the pathogen. In the resistant pepper, the pathogen remained on root epidermal surface at one day after inoculation, embedded and captured in root exudation materials composed of proteins and polysaccharides. Also the pathogen appeared to be blocked in its progression at the early infection stages by thickened middle lamellae. At 3 days after inoculation, the oomycete hyphae were still confined to epidermal cells of the root and at most outer peripheral cortical cells of the stem, resulting from their invasion blocked by wound periderms formed underneath the infection sites and/or cell wall appositions bounding the hyphal protrusions. All of these aspects suggest that limitation of disease development in the resistant pepper may be due to the inhibition of the pathogen penetration, infection, invasion, and colonization by the defense structures such as root exudation materials, thickened middle lamellae, wound peridems and cell wall appositions.