• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.1
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• pp.76-83
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• 1985

A hypothesis that artificial reforming of corn canopy could improve solar light penetration and dry matter production was tested in corn fields (var. Suwon 19) with three planting densities; low (60 ${\times}$ 40cm), medium (60 ${\times}$ 24cm) and high (60 ${\times}$ 16cm). Natural canopy was found that leaf orientations were even over all azimuth but somewhat inclined toward north-south direction and leaf angle ranged 38$^{\circ}$ to 71$^{\circ}$ from horizontal surface. Reforming corn canopy included following treatments: 1) natural canopy planted in north-south rows (natural canopy), 2)east-west plane canopy planted in north-south rows (E-W canopy), 3)east-west plane canopy and upright leaves in north-south rows, 4)north-south plane canopy (N-S canopy) in east-west rows. After corn plots were installed with training system by supporting poles and connecting wires, corn leaves were induced to a reforming direction and tied on wire. Average light intensity at the mid-point of plant height showed 5-10% increases in E-W canopy and in E-W canopy plus upright leaves, but a 2-10% decrease in N-S canopy from natural canopy. At yellow ripe stage, total dry wt. was increased in E-W canopy but not in N-S canopy. The E-W canopy produced 3-10% more grain yield than natural canopy. Though E-W canopy plus upright leaves yielded less at low density, it yielded up to 10% more at higher density. The N-S canopy yielded similar to low compared with natural canopy. These results suggests that reforming canopy toward solar incident direction increases light penetration into lower canopy, photosynthetic efficiency and grain yield, especially at high planting density in corn.

• Korean Journal of Animal Reproduction
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• v.15 no.1
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• pp.59-66
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• 1991

This study was carried out to investigate the length of the estrous cycle and duration of estrus in Korean native goats. The effects of the type of last estrus : induced or natural, and the length of preceeding estrous cycle on the subsequent cycle and duration of estrus in goats were also examined. From 481 observations, the mean length of estrous cycles was 18.1${\pm}$0.5days. The cycle length was significantly(P<0.05) shorter following induced estrus (15.2${\pm}$0.8 d) than natural estrus(19.0${\pm}$0.6 d). Significantly higher(P<0.05) incidence of short estrous cycle was observed following induced estrus(40%) than natural estrus(27%). The frequency distribution in the estrous cycle was 30%, 3%, 56% and 11% for short(3-11 d), medium(12-16 d), normal(17-24 d) and long(${\geqq}$25 d), respectively. The most frequent type of short estrous cycle was 6 days in length. Mean duration of estrus was 34.0${\pm}$0.5 h with a range of 18 to 84 h. Duration of estrus was not significantly different the preceeding natural (33.8${\pm}$0.6 h) and induced estrus (34.4${\pm}$1.1 h), and was not significantly affected by the last cycle length. These results suggest that the short estrus cycles are more frequent following induced estrus than natural one, and the duration of estrus are affected greatly by the various intrinsic and extrinsic factors.

• Molecules and Cells
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• v.20 no.1
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• pp.74-82
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• 2005

Glutaredoxins (Grxs) are thioloxidoreductases which are required for maintaining thiol/disulfide equilibrium in living cells. The Grx3 gene, which encodes one of the three monothiol Grxs in the fission yeast Schizosaccharomyces pombe, was characterized, and its transcriptional regulation studied. Genomic DNA encoding Grx3 was isolated by PCR, and a plasmid pTT3 carrying this DNA was produced. The DNA sequence has 1,267 bp, which would encode a monothiol Grx of 166 amino acids with a molecular mass of 18.3 kDa. The putative protein has 27% homology with Grx5, and contains many hydrophobic amino acid residues in its N-terminal region. S. pombe cells harboring pTT3 had increased Grx activity and enhanced survival on minimal medium plates containing aluminum (5 mM), BSO (0.05 mM), menadione (0.01 mM) or cadmium (0.2 mM). The 568 bp upstream region of Grx3 was fused into the promoterless b-galactosidase gene of the shuttle vector YEp367R to generate fusion plasmid pMJS10. Potassium chloride (KCl) and metals including aluminum and cadmium enhanced the synthesis of ${\beta}$-galactosidase from the fusion gene. The synthesis of ${\beta}$-galactosidase was also enhanced, in a Pap1-dependent manner, by fermentable carbon sources such as glucose (at low concentrations) and sucrose, but not by non-fermentable carbon sources such as ethanol and acetate. Grx3 mRNA increased in response to treatment with BSO. These observations indicate that S. pombe Grx3 is involved in the response to stress, and is regulated by stress.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.331-336
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• 1991

In order to utilize natural cellulosic materials as a fermentative substrate, saccharification of a various kind of native cellulosic materials was performed by using cellulase from the isolated strain, Pseudomonas sp. LBC-505 which potently produced cellulase complex and xylanase. Cellulase complex production was repressed by the low concentration of glucose, induced by cellulosic compounds such as CMC, wheat bran and rice straw et al. and showed to be highest on the PY-CMC medium containing 5% (w/v) wheat bran instead of CMC. Optimal temperature for enzyme reactions of CMCase and xylanase was $50^{\circ}C$, and $55^{\circ}C$ for $\beta$-glucosidase. Optimal pH for these enzyme reaction was 6.6. Rate of saccharification for natural cellulose was low by the treatment of crude enzyme. Among their substrates, rice straw was the most effective substrate of enzymatic reaction in this work. After treating rice straw with 5% (v/v) HC1 and hydrolysing with crude enzyme, rate of saccharification was 18.4% (w/w) on dry substrate. Sugars of cellulosic hydrolyzate mainly contained glucose, xylose and cellobiose.

• Journal of Adhesion and Interface
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• v.18 no.3
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• pp.118-126
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• 2017

In a natural fiber-reinforced composite material, many studies have been devoted to improving the interfacial adhesion between natural fiber and polymer matrix and the composite properties through various fiber surface modifications. In the present study, waste wool-reinforced polypropylene matrix composites were fabricated by compression molding and their mechanical and impact properties were characterized. As a result, the tensile and flexural properties and the impact strength of waste wool/polypropylene composites strongly depended on the treatment medium, alkali treatment with sodium hydroxide (NaOH) and silane treatment with 3-glycidylpropylsilane(GPS). The composite with waste wool by silane treatment exhibited higher mechanical properties and impact resistance than that by alkali treatment. The fracture surfaces of the composites support qualitatively the increased properties, showing the improved interfacial bonding between the waste wool and the polypropylene matrix.

• KSBB Journal
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• v.28 no.6
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• pp.408-414
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• 2013

In order to obtain functional materials from aloe callus, we cultured Aloe vera L. leaf on MS medium added 0.2 mg/L IAA, 0.3 mg/L kinetin and 100 mg/L grape or/and apple juice for 30 days. While a callus differentiation during callus culture did not show, the cultured leaves were uniquely released extracellular material into the agar plate. After cultivation for 18 days, the cultured leaf and agar were harvested for extraction a functional material. The materials extracted were measured on the amount of total phenols, flavonoids and polysaccharides and determined on the antioxidant and antimicrobial activity. In result, callus extracts of additive free (CT) and added apple juice (2T) had more amount of phenol compound ($659{\mu}g/mL$, $533{\mu}g/mL$) and flavonoid ($580{\mu}g/mL$, $501{\mu}g/mL$) than natural leaf (p: $525{\mu}g/mL$, f: $301{\mu}g/mL$). However, the extract of natural leaf had the better effect of lipid peroxidation and polysaccharide content than the culture extract. All samples extracted had same effect on the nitrite scavenging activity. On the other hand, only 2T extract showed excellent 72% nitric oxide scavenging activity. The agar extract was also confirmed to contain polyphenol compound and polysaccharide content that had antioxidant and antimicrobial activity partly.

• Structural Engineering and Mechanics
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• v.58 no.6
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• pp.1045-1075
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• 2016

Shallow footings are one of the most common types of foundations used to support mid-rise buildings in high risk seismic zones. Recent findings have revealed that the dynamic interaction between the soil, foundation, and the superstructure can influence the seismic response of the building during earthquakes. Accordingly, the properties of a foundation can alter the dynamic characteristics (natural frequency and damping) of the soil-foundation-structure system. In this paper the influence that shallow foundations have on the seismic response of a mid-rise moment resisting building is investigated. For this purpose, a fifteen storey moment resisting frame sitting on shallow footings with different sizes was simulated numerically using ABAQUS software. By adopting a direct calculation method, the numerical model can perform a fully nonlinear time history dynamic analysis to realistically simulate the dynamic behaviour of soil, foundation, and structure under seismic excitations. This three-dimensional numerical model accounts for the nonlinear behaviour of the soil medium and structural elements. Infinite boundary conditions were assigned to the numerical model to simulate free field boundaries, and appropriate contact elements capable of modelling sliding and separation between the foundation and soil elements are also considered. The influence of foundation size on the natural frequency of the system and structural response spectrum was also studied. The numerical results for cases of soil-foundation-structure systems with different sized foundations and fixed base conditions (excluding soil-foundation-structure interaction) in terms of lateral deformations, inter-storey drifts, rocking, and shear force distribution of the structure were then compared. Due to natural period lengthening, there was a significant reduction in the base shears when the size of the foundation was reduced. It was concluded that the size of a shallow foundation influences the dynamic characteristics and the seismic response of the building due to interaction between the soil, foundation, and structure, and therefore design engineer should carefully consider these parameters in order to ensure a safe and cost effective seismic design.

• Journal of the Korean Chemical Society
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• v.48 no.2
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• pp.137-143
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• 2004

The determination of 2-mercapto-1-methyl-imidazole (MMI) in 5.0${\times}10^{-2}$ M lithium perchlorate suporting electrolyte has been investigated by the differential pulse polarography. The optimum condition of MMI analysis was as follows; -0.9 volts initial potential, 0.08 mV pulse height, 2 mV/sec scan rate, and medium mercury drop size. Standard calibration curve showed a good linearlity in the range of 1.0${\times}10^{-7}M\;to\;8.0{\times}10^{-5}$ M and the detection limit has been (2.2${\pm}0.1){\times}0.1^{-9}$ M. This method was applicated for the determination of MMI in antithyroid drug without interference of additives.

• Korean Journal of Optics and Photonics
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• v.18 no.4
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• pp.270-273
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• 2007

We have investigated the output characteristics of the 946 nm Nd:YAG laser which is longitudinally pumped by a fiber coupled laser diode. The temperature of a Nd:YAG crystal mount was kept constant by a controller with thermoelectric cooler. As a result, we measured more intense output at a low temperature, and then the maximum output power was measured to be 870 mW when the pumping power and the temperature were 9.95 W and $5^{\circ}C$, respectively. It appeared that output was decreased above 10 W pump power because of the thermal effects in gain medium.

• Journal of Plant Biotechnology
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• v.34 no.2
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• pp.145-152
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• 2007

Lactoferrin is an 80-kDa iron-binding glycoprotein known to exert many biological activities, such as facilitating iron absorption and having antimicrobial and anti-inflammatory effects. Rice can be a useful target for edible food plants to introduce human lactoferrin, because it has lower allergenicity and is likely to be safer than microorganisms or transgenic animals. A cDNA fragment encoding human lactoferrin (HLF) driven by the maize polyubiquitin promoter, along with herbicide resistance gene (bar) driven by CaMV 35S promoter, was introduced into rice (Oryza sativa L. cv. Dong Jin) using the Agrobacterium -mediated transformation system. Putative transformants were initially selected on the medium containing bialaphos. The stable integration of the bar and HLF genes into transgenic rice plants was further confirmed through polymerase chain reaction (PCR) and Southern blot analyses. The expression of the full length HLF protein from various tissues such as grains and young leaves of transgenic rice was verified by Western blot analysis. Analysis of progeny also demonstrated that introduced genes were stably inherited to the next generation at the Mendelian fashion.