• Current Research on Agriculture and Life Sciences
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• v.11
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• pp.25-30
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• 1993

The buds of Hayward/Bruno tree were damaged from $-7^{\circ}C$ but serious damage was found on the buds treated at $-15^{\circ}C$ and $19^{\circ}C$. The bark tissue was more suceptible to low temperature than the bud. The trees were survived and bursted their at all on the top of the graft union and new shoots were formed from the rootstock of the tree. Yellowish area on the leaf surface was found, which is believed that as a result of low temperature. From these, the kiwifruit trees must be grafted with cold tolerant rootstocks will be clarified in future.

• The Korean Journal of Mycology
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• v.48 no.1
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• pp.69-74
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• 2020

In September 2017, a heavy damage by premature defoliation with the zonate leaf spots was observed in several shrubs of Lespedeza cyrtobotrya growing at Mt. Obongsan in Chuncheon, Korea. Numerous cone-shaped, white sporophores of a fungus were observed on lesions of the abaxial leaf surface. A similar fungus was isolated in September 2019 from the leaves of L. cyrtobotrya growing at Mt. Taegisan in Hoengseong, Korea. The morphological characteristics of the sporophores were consistent with those of Grovesinia moricola. The species identification was confirmed by sequencing the internal transcribed spacer (ITS) region of the ribosomal DNA from the two isolates (KACC48417 and KACC48934). The fungal pathogenicity was determined by an artificial inoculation in conditions of relative humidity and temperature of 100% and 15±2℃, respectively. This is the first report of association of G. moricola with L. cyrtobotrya in Korea.

• Korean Journal of Food Science and Technology
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• v.44 no.1
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• pp.34-40
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• 2012

This study was carried out to investigate the optimal roasting conditions for developing perilla leaf leached tea, which has high functional Perilla frutescens leaves. The roasting processes were carried out with variations in roasting temperature ($120-200^{\circ}C$) and roasting time (15-35 min), the response surface methodology was applied to monitor the changes in qualities of the roasted Perilla frutescens leaves. The antioxidant, bioactive substance in roasted Perilla frutescens leaves, and their extracts were the quality parameters. The total polyphenol and total flavonoid contents increased with time and temperature up to 25 min and $160^{\circ}C$. Antioxidative activities showed a positive correlation with the amount of phenolic compound. Caffeic acid and rosmarinic acid contents increased with time up to a mild temperature, $160^{\circ}C$, while they decreased at high temperatures over $160^{\circ}C$. The optimum roasting conditions selected for developing perilla leaf leached tea were thus $180^{\circ}C$ and 20 min, given the conditions in the above experiments.

• Korean journal of applied entomology
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• v.41 no.4
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• pp.255-261
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• 2002

Tomato russet mite, Aculops lycopersici Massee (Acari. Eriophyidae) was recorded in Korea and their SEM observations, distribution, host range, development on different temperature, and chemical control method were studied. Tomato russet mite is a microscopic animal (134.9 $\mu\textrm{m}$) with 2 pairs of legs which had 4 rays of feathered craw. Infected leaf turn reddish brown, stem loss hair, become shiny or surface cross-cracked, and shoot wilted or shrunk. Surface of fruit around fruit stalk appeared rusted or cross-cracked. It was found in glass greenhouse at Buyeo and Yuseong in Chungnam Province, Pyeongchang in Gangwon Province, and Chilgok and Guryongpo in Gyeongbuk Province. Convolvulus, black nightshade, chinese lanternplant, eggp1ant, morning glory, petunia, potato, pepper, tobacco and tomato were confirmed as a host plant in inoculation test. It could develop at temperature around $15-30^{\circ}C$, it took 6-11 days from eggs to adult, higher temperature shorten its life cycle. Female lived longer than male and it lived as long as 12 days at 25-28"C. Among acaricides tested, fenazaquin and cypermethrin were most effective.tive.

• Journal of the Korean Society of Tobacco Science
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• v.3 no.1
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• pp.30-40
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• 1981

The moisture sorption and desorption isotherms of various tobaccos were obtained over a relative humidity range from 0 to 90% at $20^{\circ}C$ and $30^{\circ}C$. The hysteresis effect, constant and rate of moisture sorption and desorption, monomolecular-layer moisture content, and specific surface area were analyzed from the obtained data. The moisture sorption and desorption isotherms showed a different characteristics for different tobacco varieties. At a lower humidity range below 50% RH, Burley tobacco had higher moisture sorption and desorption figures than Hicks and Basma, while, at a higher humidity range above 50% RH, Hicks had higher values than the others. The hysteresis effect of tobacco were greater in an intermediate humidity range (40-70% RN), and Basma showed a greater effect than the others. The sorption and desorption constant (K) increased with temperature, but decreased with RH, and Burley tobacco had larger K values, while Hicks had smaller K values than others. The sorption and desorption rate of Burley tobacco were greater than the other tobaccos. The monomolecular-layer moisture was 27.8 and 51.4mg/g, and the specific surface was 101 and $186m^2/g$, for Basma and Burley, respectively.

• KSTLE International Journal
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• v.7 no.1
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• pp.14-17
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• 2006

In this paper, we report on the replication of surface topography of natural leaf of Lotus onto thin polymeric films using a capillarity-directed soft lithographic technique. PDMS molds were used to replicate the surface. The replication was carried out on poly(methyl methacrylate) (PMMA) film coated on silicon wafer. The patterns so obtained were investigated for their friction properties at micro-scale using a ball-on-flat type micro-tribo tester, under reciprocating motion. Soda lime balls (1 mm diameter) were used as counterface sliders. Friction tests were conducted at a constant applied normal load of $3000{\mu}N$ and speed of 1mm/s. All experiments were conducted at ambient temperature ($24{\pm}1^{\circ}C$) and relative humidity ($45{\pm}5%$). Results showed that the patterned samples exhibited superior tribological properties when compared to the silicon wafer and non patterned sample (PMMA thin film). The reduced real area of contact projected by the surfaces was the main reason for their enhanced friction property.

• International Journal of Automotive Technology
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• v.7 no.3
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• pp.295-301
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• 2006

A new combustion method of high compression ratio SI engine was studied and proposed in order to achieve high thermal efficiency, comparable to that of CI engine. Compression ratio of SI engine is generally restricted by the knocking phenomena. A combustion chamber profile and a cranking mechanism were studied to avoid knocking with high compression ratio. Because reducing the end-gas temperature will suppress knocking, a combustion chamber was considered to have a wide surface at the end-gas region. However, wide surface will lead to large heat loss, which may cancel the gain of higher compression ratio operation. Thereby, a special cranking mechanism was adapted which allowed the piston to move rapidly near TDC. Numerical simulations were performed to optimize the cranking mechanism for achieving high thermal efficiency. An elliptic gear system and a leaf-shape gear system were employed in numerical simulations. Livengood-Wu integral, which is widely used to judge knocking occurrence, was calculated to verify the effect for the new concept. As a result, this concept can be operated at compression ratio of fourteen using a regular gasoline. A new single cylinder engine with compression ratio of twelve and TGV(Tumble Generation Valve) to enhance the turbulence and combustion speed was designed and built for proving its performance. The test results verified the predictions. Thermal efficiency was improve over 10% with compression ratio of twelve compared to an original engine with compression ratio of ten when strong turbulence was generated using TGV, leading to a fast combustion speed and reduced heat loss.

• Korean Journal of Remote Sensing
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• v.22 no.3
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• pp.175-182
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• 2006

Because of the phenological variation of vegetation growth in temperate region, it is often difficult to accurately assess the surface conditions of agricultural croplands, grasslands, and disturbed forests by multi-spectral remote sensor data. In particular, the spectral similarity between soil and dry vegetation has been a primary problem to correctly appraise the surface conditions during the non-growing seasons in temperature region. This study analyzes the spectral characteristics of the mixture of dry vegetation and soil. The reflectance spectra were obtained from laboratory spectroradiometer measurement (GER-2600) and from EO-1 Hyperion image data. The reflectance spectra of several samples having different level of dry vegetation fractions show similar pattern from both lab measurement and hyperspectral image. Red-edge near 700nm and shortwave IR near 2,200nm are more sensitive to the fraction of dry vegetation. The use of hyperspectral data would allow us for better separation between bare soils and other surfaces covered by dry vegetation during the leaf-off season.

• Journal of Electrochemical Science and Technology
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• v.10 no.2
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• pp.231-243
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• 2019

The methanolic extracts of the leaves and stem of the plant Lepidagathis keralensis were evaluated for anticorrosion behavior against mild steel in 1M HCl. Corrosion inhibition studies were done by gravimetric method, electrochemical impedance spectroscopy and potentiodynamic polarization methods. Surface morphology of mild steel in the presence and absence of inhibitors were studied using SEM analysis. UV-Vis studies were also done to evaluate the mechanism of inhibition. Both the extracts showed good inhibition efficiency which increased with increase in concentration of the inhibitor and decreased with increase in temperature. The mechanism of inhibition was explained by adsorption which obeyed Langmuir adsorption isotherm. Thermodynamic calculations revealed a combination of both physisorption and chemisorption of the inhibitor on the surface of mild steel. The extracts behaved as mixed type inhibitors as determined by polarization studies. Quantum chemical studies on Phenoxyethene, one of the major components in the leaf extract of the plant was also carried out to support the experimental results.

• The Korean Journal of Mycology
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• v.30 no.2
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• pp.173-175
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• 2002

Sooty leaf blight was found on Dendrobium sp. in several farmers' fields located in Namji-eup, Changnyeong-gun, Gyeongnam province, Korea in 2001. Symptoms of the disease appeared on leaves. Sooty leaf spots were started with amphigenous, subeircular to irregular spots, with light grayish brown to black color with definite margin lines on the upper surface of leaves. Infected leaves became defoliated and whole plants eventually were died. The infection rates of the disease in the surveyed area reached up to 64.8%, in the early September. Conidiophores of the causal fungus were dark grayish brown in color, densely fasciculate, straight, curved to sinuous, branched, $5{\sim}10$ septate and $63{\sim}164{\times}3.2{\sim}4.9{\mu}m$ in size. Conidia were pale to olivaceous in color, obclavatecylindric, straight to slightly curved in shape, $1{\sim}5$ septate and $46{\sim}98{\times}3.2{\sim}3.9{\mu}m$ in size. The optimum temperature for mycelial growth of the fungus was $25^{\circ}C$. The fungus was identified as Pseudocercospora dendrobii on the basis of its mycological characteristics. This is the first report on sooty leaf light of Dendrobium sp. caused by Pseudocercospora dendrobii in Korea.