• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.380-386
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• 2018

A sustainable method was developed for the upgrade of biomass derived vanillin (a typical model compound of lignin) into the potential liquid biofuels over a layered double hydroxide supported Pd catalyst (abbreviated as CoAl-LDH/Pd). The CoAl-LDH/Pd catalyst showed high catalytic activity towards the hydrodeoxygenation of vanillin into 2-methoxy-4-methylphenol (MMP) under mild conditions in aqueous media. High MMP yield up to 86% was produced at $120^{\circ}C$ after 4 h. Kinetic studies revealed that the rate-determining step for the hydrodeoxygenation of vanillin was the hydrogenolysis of vanillyl alcohol. More importantly, the CoAl-LDH/Pd catalyst was highly stable without the loss of activity.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.328-328
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• 2017

Drought is a major limiting factor that reduces rice production and occurs often especially under recent climate change. Plants have the ability to alter their developmental morphology in response to changing environment, which is known as phenotypic plasticity. In our previous studies, we found that one chromosome segment substitution line (CSSL50 derived from Nipponbare and Kasalath crosses) showed no differences in shoot and root growth as compared with the recurrent genotype, Nipponbare under non-stress condition but showed greater growth responses compared with Nipponbare under mild drought stress condition. We hypothesized that reducing root respiration as metabolic cost, which may be largely a consequence of aerenchyma formation would be one of the key mechanisms for root plasticity expression. This study aimed to evaluate the root respiration and aerenchyma formation under various soil moisture conditions among genotypes with different root plasticity. CSSL50 together with Nipponbare and Kasalath were grown under waterlogged conditions (Control) and mild drought stress conditions (20% of soil moisture content) in a plastic pot ($11cm{\times}14cm$, ${\varphi}{\times}H$) and PVC tube ($3cm{\times}30cm$, ${\varphi}{\times}H$). Root respiration rate was measured with infrared gas analyzer (IRGA, GMP343, Vaisala, Finland) with a closed static chamber system. There was no significant difference between genotypes in control for shoot and root growth as well as root respiration rate. In contrast, all the genotypes increased their root respiration rates in response to mild drought stress. However, CSSL50 showed lower root respiration rate than Nipponbare, which was associated by higher root aerenchyma formation that was estimated based on internal gas space (porosity) under mild drought stress conditions. Furthermore, there were significant negative correlations between root length and root respiration rate. These results imply that reducing the metabolic cost (= root respiration rate) is a key mechanism for root plasticity expression, which CSSL50 showed under mild drought.

• Corrosion Science and Technology
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• v.22 no.2
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• pp.73-89
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• 2023

Due to continuous promotion of green alternatives to toxic petrochemicals by government policies, research efforts towards the development of green corrosion inhibitors have intensified recently. The objective of the current work was to develop novel green and sustainable corrosion inhibitors derived from 4-aminoantipyrine to effectively prevent corrosion of mild steel in corrosive environments. Gravimetric methods were used to investigate corrosion inhibition of 4-((furan-2-ylmethylene)amino)antipyrine (FAP) and 4-((pyridin-2-ylmethylene)amino)antipyrine (PAP) for mild steel in 1 M HCl. FAP and PAP were subjected to quantum chemical calculations using density functional theory (DFT). DFT was used to determine the mechanism of mild steel corrosion inhibition using inhibitors tested in HCl. Results demonstrated that these tested inhibitors could effectively inhibit mild steel corrosion in 1.0 M HCl. At 0.0005 M, these inhibitors' efficiencies for FAP and PAP were 93.3% and 96.5%, respectively. The Langmuir adsorption isotherm was obeyed by these inhibitors on the mild steel surface. Values of adsorption free energies, ΔG^o_ads, revealed that FAP followed chemical and physical adsorptions.

• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.373-378
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• 2000

The crevice corrosion of local corrosion occur when the gap exist on metal surface. This crevice corrosion happen to region such as flange of pipe, contact part of casing, under gasket and packing, between valve disk and seat of pump etc. Especially The crevice corrosion of mild steel(SS 400) get serious. This paper was studied on the crevice corrosion of SS 400 in fluid environment. In $0\%,\;2\%,\;3.5\%,\;5\% NaCl$ solution, the aspect of the crevice corrosion and polarization behavior under the crevice corrosion was investigated. And Weight loss rate of SS 400 with crevice and non-crevice was measured according to the NaCl concentration. The main results obtained are as follows : 1) Under crevice corrosion, the corrosion potential become less noble as the concentration of NaCl solution increased. 2) The current density under open circuit potential was high drained as concentration of NaCl solution increased by $3.5\%$ but the concentration increased over $3.5\%$, the current density was low drained. 3) The weight loss rate of SS 400 was increased as concentration of NaCl solution Increased by $3.5\%$, but the concentration increased over $3.5\%$, that of SS 400 was decreased. 4) Effect of oxygen for crevice corrosion in the concentration of $3.5\%$ NaCl solution become sensitive than that $0\%$ NaCl solution.

• Research in Plant Disease
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• v.9 no.2
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• pp.89-93
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• 2003

An isolate of Tobacco mosaic virus (TMV) was isolated from potato cultivar ‘Chubak’ showing vein clearing and mild mosaic at Namhae in Korea. This isolate, TMV-St, was differentiated from other tobamoviruses based on biological properties, serological relationships and nucleotide sequence analyses of coat protein genes. TMV-St caused typical symptoms on four indicator plants as compared to the tobamovirus of TMV-U1, Pepper mild mottle virus (PMMoV), and Tomato mosaic virus (ToMV), which caused economic losses in Solanaceous vegetables, tomato, pepper, and eggplant. Remarkably, the TMV-St induced distinctly different symptom of systemic chlorotic spots on Chenophodium murale. On C. murale, Gomphorena globosa, and Nic-otiana rustica, the four viruses were classed by the virulence of systemic or local infections. In serological test TMV-St antiserum showed a precipitation line with each other tabamovirus. The CP gene of TMV-St contain 477 nucleotides, and the nucleotides sequence was the most similar to that of TMV-U1.

• The Plant Pathology Journal
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• v.18 no.6
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• pp.323-327
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• 2002

A rod-shaped virus was isolated from pepper showing mild mosic during the winter growing seasons of 2001 and 2002 in Korea. Based on its biological reactions, serological relationships, reverse transcription-poly-merase chain reaction (RT-PCR) using specific primers, and nucleotide sequence analysis of coat protein (CP) gene, the isolated virus was identified as Tobacco mild green mosaic virus (TMGMV) and designated as Korean pepper isolate (TMGMV-KP). Crude sap from infected tissue was mechanically transmitted to various indicator plants, which produced characteristic symptoms of tobamovirus infection. However, no symptom was observed in Gomphorena globosa. In RT-PCR assays with specific primers toy respective detection of TMGMV, Tobacco mosaic virus (TMV), Pepper mild mottle virue (PMMoV), and Tomato mosaic virus (ToMV), a single strong band of about 500 bp in length was produced from the sample used only with TMGMV primers. The amplified DNA was cloned and the nucleotide sequence was determined. Sequence comparisons with the CP gene of other tobamoviruses indicated that TMGMV-KP shared 99.3％ identity with TMGMV Japanese isolate and only 59.1, 58.6, and 58.1％ identity with TMV, PMMoV and ToMV, respectively. This is the first report of TMGMV in Korea.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.749-751
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• 2016

Due to the advent of virtual reality, the past communication method using images and video through the expansion into three-dimensional space has been provided more realistic and seamless interaction environment. Unlike reality, virtual reality is under a full human control and due to this benefit can be used as a substitute for reality therefore medicine and healthcare area has attracted attention in the prevention and treatment of dementia utilizing virtual reality. The research provided in this paper is aimed to design a virtual reality-based mild cognitive impairment prevention training system, focusing on the Symptoms of Alzheimer's precursor, mild cognitive impairment.

• Journal of Audiology & Otology
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• v.23 no.2
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• pp.83-88
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• 2019

Background and Objectives: Mild cognitive impairment (MCI) is a disorder that usually occurs in the elderly, leading to dementia in some progressive cases. The purpose of this study is to examine the utility of central auditory processing tests as early diagnostic tools for identifying the elderly with MCI. Subjects and Methods: This study was conducted on 20 elderly patients with MCI and 20 healthy matched peers. The speech perception ability in a quiet environment and in the presence of background noise and also temporal resolution were assessed by using Speech Perception in Noise (SPIN) and Gap in Noise (GIN) tests, respectively. Results: The results indicated that the ability to understand speech in a quiet environment did not differ significantly between the two groups. However, SPIN at the three signal-to-noise ratios and the temporal resolution scores were significantly different between the two groups (p<0.001). Conclusions: Individuals with MCI appear to have poorer speech comprehension in noise and a lower temporal resolution than those of the same age, but without cognitive defects. Considering the utility of these tests in identifying cognitive problems, we propose that since the GIN test seems to be less influenced by intervening factors, this test can therefore, be a useful tool for the early screening of elderly people with cognitive problems.

• Korean Journal of Audiology
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• v.23 no.2
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• pp.83-88
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• 2019

Background and Objectives: Mild cognitive impairment (MCI) is a disorder that usually occurs in the elderly, leading to dementia in some progressive cases. The purpose of this study is to examine the utility of central auditory processing tests as early diagnostic tools for identifying the elderly with MCI. Subjects and Methods: This study was conducted on 20 elderly patients with MCI and 20 healthy matched peers. The speech perception ability in a quiet environment and in the presence of background noise and also temporal resolution were assessed by using Speech Perception in Noise (SPIN) and Gap in Noise (GIN) tests, respectively. Results: The results indicated that the ability to understand speech in a quiet environment did not differ significantly between the two groups. However, SPIN at the three signal-to-noise ratios and the temporal resolution scores were significantly different between the two groups (p<0.001). Conclusions: Individuals with MCI appear to have poorer speech comprehension in noise and a lower temporal resolution than those of the same age, but without cognitive defects. Considering the utility of these tests in identifying cognitive problems, we propose that since the GIN test seems to be less influenced by intervening factors, this test can therefore, be a useful tool for the early screening of elderly people with cognitive problems.

• Research in Plant Disease
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• v.22 no.1
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• pp.25-31
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• 2016

During a field survey in 2014, a Rorippa palustris plant showing virus-like symptom was collected from a pepper field in Dangjin in Korea. The collected sample was subjected to examine infection with pepper-infecting viruses. Molecular diagnosis assay showed that the collected R. palustris sample was co-infected with Pepper mild mottle virus (PMMoV) and Cucumber mosaic virus (CMV). This is the first identification of PMMoV from R. palustris and the first report of CMV infection of R. palustris in Korea. To examine phylogenetic positions of the identified PMMoV and CMV isolates, their complete genome sequences of were determined and compared with those of previously reported isolates of the cognate viruses. Phylogenetic analyses revealed the isolates of PMMoV and CMV obtained from R. palustris are closely related to the pepper isolates of the cognate viruses. Our results suggest that R. palustris could act a weed reservoir of PMMoV and CMV.