• Journal of the Korean Wood Science and Technology
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• v.36 no.4
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• pp.37-43
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• 2008

The research attempted to develop an eco-friendly wood adhesive based on vegetable oil (soybean oil), the renewable and sustainable natural resources, using ozonification technology for the chemical structure modification. The soybean oils (SBO) were reacted with $O_3$ at the rate of 7.13 g/h for different times, 15 minutes, 30 minutes, 60 minutes, and 120 minutes. Modified chemical structure of the ozonized SBOs were examined by Fourier transform Infrared (FT-IR) spectrum. The FT-IR spectrum of SBO had an absorbance peak at $3010cm^{-1}$ that is the characteristic peak of the unsaturated double bonds. As ozone treatment time increased, the peak of the double bond was disappeared and aldehyde or carboxyl peak appeared at $1700cm^{-1}$. The dry, wet, and cyclic boiling bond strengths of the ozonized SBO mixed with polymeric diphenylmethane-4, 4-diisocyanate (pMDI) were also investigated. In the dry shear test, all strengths met constantly the standard requirement of $7.0kgf/cm^2$ (KS F3101 2006). The bond strengths gradually increased with increasing ozone treatment time. The highest strength showed at 60 minutes ozone treatment and decreased values at 120 minutes. In the cyclic boiling shear test, 30, 60 and 120 minutes exceeded the standard requirement.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.27-27
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• 2011

For the design of real applicable molecular devices, current-voltage properties through molecular nanostructures such as metal-molecule-metal junctions (molecular junctions) have been studied extensively. In thiolate monolayers on the gold electrode, the chemical bonding of sulfur to gold and the van der Waals interactions between the alkyl chains of neighboring molecules are important factors in the formation of well-defined monolayers and in the control of the electron transport rate. Charge transport through the molecular junctions depends significantly on the energy levels of molecules relative to the Fermi levels of the contacts and the electronic structure of the molecule. It is important to understand the interfacial electron transport in accordance with the increased film thickness of alkyl chains that are known as an insulating layer, but are required for molecular device fabrication. Thiol-tethered RuII terpyridine complexes were synthesized for a voltage-driven molecular switch and used to understand the switch-on mechanism of the molecular switches of single metal complexes in the solid-state molecular junction in a vacuum. Electrochemical voltammetry and current-voltage (I-V) characteristics are measured to elucidate electron transport processes in the bistable conducting states of single molecular junctions of a molecular switch, Ru(II) terpyridine complexes. (1) On the basis of the Ru-centered electrochemical reaction data, the electron transport rate increases in the mixed self-assembled monolayer (SAM) of Ru(II) terpyridine complexes, indicating strong electronic coupling between the redox center and the substrate, along the molecules. (2) In a low-conducting state before switch-on, I-V characteristics are fitted to a direct tunneling model, and the estimated tunneling decay constant across the Ru(II) terpyridine complex is found to be smaller than that of alkanethiol. (3) The threshold voltages for the switch-on from low- to high-conducting states are identical, corresponding to the electron affinity of the molecules. (4) A high-conducting state after switch-on remains in the reverse voltage sweep, and a linear relationship of the current to the voltage is obtained. These results reveal electron transport paths via the redox centers of the Ru(II) terpyridine complexes, a molecular switch.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.3
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• pp.208-214
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• 1990

Phytoplankton samples for this study were collected by Van Dorn Sampler at 28 oceanographic stations in the southern waters of Korea in February, April and August, 1988 to characterize the distribution and species composition of phytoplankton and their relation to the movement of water masses. During the study periods, phytoplankton standing crops in the southern waters were maximum in April and minimum in February. When the geographical distribution and abundance of the phytoplankton were considered, the highest standing crops were found near the front zone formed between Cheju Island and Tsushima Island. Therefore, their abundance depends ell the location of the front zone. On the other hand, there were relatively low standing crops in the open sea off the coastal area from the front zone in February and August. The cause of the unusal low standing crops found in August at the station 205/01, the central part of the coastal area of the southern waters where the largest standing crops occurred in February and April, seems to be due to the intrusion of Tsushima warm waters. This is because the waters at the station have high temperature and salinity, poor dissolved oxygen and nutrient salts, which are identical to the characteristics of proper Tsushima warm waters. It seems that these warm waters may affect the poor productivity in this area. Seventy-two species in thirty-three genera of the phytoplankton were indentified from the samples. Among them, 61 species in 27 genera belong to diatoms and 12 species in 7 genera to dinoflagellates. The largest number of phytoplankton species occurred in August while the largest number of the tells in April. Predominant species were Eucampia zodiacus in February, Skeletonema costatum and Chaetoceros curvisetus in April and Chaetoceros affinis in August. Eucampia zodiacus which was dominant in February and April seems to be a indicator of the southern coastal waters of Korea and mixed waters west of Cheju Island.

• Journal of the Korean Wood Science and Technology
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• v.27 no.3
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• pp.82-90
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• 1999

The buddhistic painting of Song-Kwang temple in Seungjoo-gun, Chonnam, Korea is not known in chronicle, but it could be estimated to works in the early 19th century through it's remaining records and qualities of materials. And it was analysed the qualities of materials consisting of pigment layer, silken-ground layer and support layer in order to preserve buddhistic painting, made back-adherent paper of the support layer proper to it, tested its compatibility, and then concluded as follows. 1. The section structures of buddhistic painting is consisted of the pigment layer, silken-ground layer of silk and the support layer of Korean hand made paper, it could be recognized that buddhistic painting in 19th century was basically composed of the pigment layer, the silken-ground layer and the support layer. Moreover the pigment layer and the silken-ground layer got adhered with glue, and sheets of support layers got back adhered with paste. 2. The support layer of buddhistic painting consisted of 5 layers and two kinds of paper were used for them. The first and second layers were composed of Korean hand made paper made of pure paper mulberry bast fibers, and the rest of them of paper that paper mulberry bast fibers were mixed into recycled hemp fibers. Though it is difficult to assert without the security of more data, finding out the then situation through the qualities of materials, it was presumed that the society in 19th century was suffered from economical difficulties and the operation of the paper industry of temples was rather difficult and so low-qualitative recycled hemp fibers might used for back-adherent paper. 3. Considering tension between silken-ground layers and support layers of this materials, newly made back-adherent paper was used for repair, and then I could conform that it was proper to back-adherent paper for repair.

• Korean journal of applied entomology
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• v.51 no.1
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• pp.39-45
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• 2012

The entomopathogenic bacterium, $Xenorhabdus$ sp., was isolated from an entomopathogenic nematode, $Steinernema$ $monticolum$. When these bacteria were injected into the hemocoel of the diamondback moth, $Plutella$ $xylostella$, they caused significant mortality. However, the bacterium was not pathogenic when it was administered orally. This study showed that $Xenorhabdus$ sp. significantly enhanced oral pathogenicity of $Bacillus$ $thuringiensis$ (Bt) against the last instar larvae of $P.$ $xylostella$. Different ratios of culture broth of $Xenorhabdus$ sp. and Bt showed significantly different pathogenicities against $P.$ $xylostella$. In field tests, the optimal bacterial mixture significantly enhanced control efficacy against $P.$ $xylostella$ compared to Bt treatment alone. These results demonstrated that $Xenorhabdus$ sp. culture broth can be developed as a potent biopesticide by enhancing the insecticidal efficacy of Bt.

• Korean Journal of Environment and Ecology
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• v.22 no.2
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• pp.98-105
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• 2008

To investigate the vegetation structure of the region from Bukhansanseong to Insubong in Bukhansan National park, 16 plost$(2500m^2)$ set up with random sampling method were surveyed. Three groups Quercus mongolica-Mixed Broad leaved community, Pinus densiflora-Quercus mongolica community, Quercus mongolica community was classified (or communities were classified) by cluster analysis. Quercus mongolica were found as a major woody plant species in Bukhansan National park region. High positive correlation were proved between Quercus mongolica and Rhododendron; Quercus mongolica and Rhus tricocarpa; Rhododendron mucronulatum and Rhododendron schlippenbachi; Symplocos chinensis and Rhododendron schlippenbachii; Acer pseudosieboldianum and Magnolia sieboldii, and relatively high negative correlation was proved between Fraxinus rhynchophylla and Rhododendron mucronulatum; Juniperus rigid a and Acer pseudosieboldianum; Styrax obassia and Acer pseudosieboldianum. Species diversity(H') of investigated groups were ranged from $1.236\sim1.319$ and it was relatively high compared to those of the ridge area of other national parks.

• Korean Journal of Organic Agriculture
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• v.16 no.3
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• pp.287-298
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• 2008

This experiment was carried out to investigate the effect of different feed conditions on growth, cast production and conversion efficiency of organic matter to the earthworm. The experiment was tested on cow manure(CM) mixed with rice hulls (RH) or rice straw(RS). The mixture ratios were designed as one time, two times and three times of cow manure volume, respectively. The CM and RH mixtures resulted better on growth rate, reproductive efficiency and wormcast production than those for CM and RS mixtures. Especially on three times of RH mixture showed the highest growth characteristics compared to the other mixtures. Although both were between 20 and 34 on carbon and nitrogen ratio, the result inferred that the difference on the growth might have been caused by feeding conditions. On the mixtures of cow manure with rice hulls(CM+RH) was significantly higher on values on the conversion rate and conversion efficiency of organic matter to earthworm tissues than the mixtures of cow manure with rice straw(CM+RS). The most concerned point of the mixture of earthworm feed is that high contents of volatile solid and total carbon that increases in conversion efficiency of organic matter to earthworm tissues, and also causes the increase in growth rate and reproductive efficiency. The wormcast could be used as a valuable plant growth medium or soil conditioner for sustainable agriculture and it may be due to their high qualities of physico-chemical properties.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.6
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• pp.442-448
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• 2021

In this work, the (K_1-xAg_x)(Ta_0.8Nb_0.2)O₃ (x=0.1-0.4) ceramics were fabricated using mixed-oxide method, and their structural and electrical properties were measured. All specimens represented a pseudo cubic structure with the lattice constant of 0.3989 nm. When 0.4 mol of Ag was added, second phases induced from metallic Ag and K₂(Ta,Nb)₆O₁₆ phase were observed. Dielectric constant and dielectric loss of K(Ta_0.8Nb_0.2)O₃ specimen doped with 0.3 mol of Ag were 2,737 and 0.446, respectively. The curie temperature was about -5℃, which does not change with Ag addition. The remanent polarization began to decrease sharply around 12~15℃, and the temperature at which the remanent polarization began to decrease as the applied voltage increased shifted to the high temperature side. The electrocaloric effect (ΔT) and electrocaloric efficiency (ΔT/ΔE) of the (K_0.7Ag_0.3)(Ta_0.8Nb_0.2)O₃ ceramics were 0.01024℃ and 0.01825 KmV^-1, respectively.

• Animal Bioscience
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• v.34 no.6
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• pp.1029-1037
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• 2021

Objective: This study was conducted to investigate effects of antifungal substance and carboxylesterase-producing inoculant on fermentation indices and rumen degradation kinetics of whole crop rice (WCR) silage ensiled at different dry matter (DM) contents. Methods: Dual-purpose inoculants, Lactobacillus brevis 5M2 and Lactobacillus buchneri 6M1, confirmed both activities of antifungal and carboxylesterase in the previous study. The WCR at mature stage was chopped, and then wilted to obtain three different DM contents consisting of 35.4%, 43.6%, and 51.5%. All WCR forages were applied distilled water (CON) or mixed inoculants with 1:1 ratio at 1×105 colony forming unit/g (INO), and ensiled into 20 L mini silo (5 kg) in quadruplicates for 108 d. Results: The INO silages had lower lactate (p<0.001) and butyrate (p = 0.022) with higher acetate (p<0.001) and propionate (p<0.001) than those of CON silages. Ammonia-N (p<0.001), lactate (tendency; p = 0.068), acetate (p = 0.030), and butyrate (p<0.001) concentrations of INO silages decreased linearly with increasing DM content of WCR forage. The INO silages presented higher lactic acid bacteria (p<0.001) with lower molds (p<0.001) than those of CON silages. Yeasts (p = 0.042) and molds (p = 0.046) of WCR silages decreased linearly with increasing DM content of WCR forage. In the rumen, INO silages had higher the total degradable fraction (p<0.001), total volatile fatty acid (tendency; p = 0.097), and acetate (p = 0.007), but lower the fractional degradation rate (p = 0.011) and propionate (p<0.001) than those of CON silage. The total degradable fraction (p<0.001), total volatile fatty acid (p = 0.001), iso-butyrate (p = 0.036), and valerate (p = 0.008) decreased linearly with increasing DM content of WCR forage, while the lag phase (p<0.001) was increased linearly. Conclusion: This study concluded that application of dual-purpose inoculants on WCR silage confirmed antifungal and carboxylesterase activities by inhibiting mold and improving rumen digestibility, while increase of wilting times decreased organic acids production and rumen digestibility.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.12
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• pp.1897-1902
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• 2018

Objective: This study was conducted to evaluate the effect of homo or hetero fermentative inoculants on fermentation quality and aerobic stability of sweet potato vine (SPV) silage containing Italian ryegrass hay as moisture absorbent. Methods: The SPV was harvested at 15% dry matter, mixed with Italian ryegrass hay at 1:1 ratio on a fresh weight basis, and chopped to 3 to 5 cm length. After then, the chopped forage mixture was ensiled into 20-L mini silos in quadruplicate for 7, 48, and 100 days after application of microbial inoculants at $1.2{\times}10^5$ colony forming units (cfu)/g of forage following: no inoculant (CON), Lactobacillus plantarum as a homo fermentative (LP), Lactobacillus buchneri as a hetero fermentative (LB), and mixture of LP and LB at 1:1 ratio as a combo fermentative (MIX). Results: The LP and MIX silages had lowest pH (p<0.001) on 7 and 48 days, while MIX and CON silages had greatest lactate concentrations (p<0.05) on 7 and 48 days, respectively. Acetate concentrations were highest (p<0.01) in LB and MIX silages on 7 days, and in LB silage on 48 days, while lactate to acetate ratios were lowest (p<0.001) in LB silages. The chemical compositions and nutrient digestibility of silage ensiled for 100 days was not affected by inoculants. On 100 days of ensiling, LB silage had lowest (p<0.01) lactate concentration and lactate to acetate ratio, but highest acetate concentration. Aerobic stability was highest (p<0.001) in LB silage followed in MIX silage. On contrast, LB silage had lowest (p<0.05) lactic acid bacteria and mold. Conclusion: The results indicated that application of LB solely had a better effect on aerobic stability than not only LP, but also MIX. However, LP application did not show beneficial effects from the viewpoints of fermentation quality and aerobic stability compared to CON.