• Corrosion Science and Technology
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• v.19 no.2
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• pp.82-88
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• 2020

This work examined the corrosion protection performance of benzoate loaded hydrotalcite/graphene oxide (HT/GO-BZ) for carbon steel. HT/GO-BZ was fabricated by the co-precipitation method and characterized by infrared spectroscopy, X-ray diffraction, and scanning electronic microscopy. The corrosion inhibition action of HT/GO-BZ on carbon steel in 0.1 M NaCl solution was evaluated by electrochemical measurements. The benzoate content in HT/GO-BZ was determined by UV-Vis spectroscopy. Subsequently, the effect of HT/GO-BZ on the corrosion resistance of the water-based epoxy coating was investigated by the salt spray test. The obtained results demonstrated the intercalation of benzoate and GO in the hydrotalcite structure. The benzoate content in HT/GO-BZ was about 16%. The polarization curves of the carbon steel electrode revealed anodic corrosion inhibition activity of HT/GO-BZ and the inhibition efficiency was about 95.2% at a concentration of 3g/L. The GO present in HT/GO-BZ enhanced the inhibition effect of HT-BZ. The presence of HT/GO-BZ improved the corrosion resistance of the waterborne epoxy coating.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.917-922
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• 2010

To assess the bioavailability of As in soils and to provide a basic information for adequate management of As contaminated fields, paddy soils and rice grains near 5 closed mines were collected and analyzed for As using sequential extraction procedure. The As contents extracted with 1M HCl against total As content in soils were ranged from 5.4 to 41.9% ($r=0.90^{**}$). However, these two contents of As in soils were not positively correlated with As concentration in rice grains. Major As fractionation of paddy soils was residual form ranging 38.1 to 84.1% except NS mine. Also, specially adsorbed fraction and fraction associated with amorphous Fe and Al oxyhydroxides, which are partially bioavailable As fractionation to the rice plant, were positively correlated with As in rice grains while fraction associated with crystalline Fe and Al oxyhydroxides and residual form were not correlated.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.1
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• pp.147-157
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• 2013

Rice is a main crop and rice field is the most important farmland in Korea. This study was conducted to propose the methodology assessing impact and vulnerability on rice production by climate change at the regional and national level in Korea. We evaluated a vulnerability of rice paddy according to the outbreak of a main disease and pest of a rice plant. As results, Jeju-do, Gyeongsangnam-do, and Jeollanam-do were more vulnerable area than others. In contrast, the southern central region including Gyeonggi-do was less vulnerable than others. The vulnerable index was significantly higher in 2050s (0.5589) than in present (0.3500). This result showed that the vulnerable to the disease and pest enlarge in the future. The adaptive capacity highly contributed to the vulnerability assessment index. The daily maximum temperature of June and the daily average temperature from May to August also contributed the climate exposure index. The area of occurring sheath blight, rice leaf blast and striped rice borer was related to the system sensitivity index. The ability of water supply (readjustment area of arable land per paddy field area) and rice production technique (rice yield per hectare) were the highly contributed variables to the adaption capacity index.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.1
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• pp.15-21
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• 2011

In this paper, the results of experimental analysis for the chemical composition and strengh verification of Bailey Panel Bridge have been presented. Some of main sections of bailey bridge colllected from military engineer troops were prepared for the chemical composition and strengh verification. The composition test and strength verification were conducted by using the optical microscope and Scanning Electron Microscope(SEM), Automatic Control Spark Emission Spectrometer(OBLF), X-ray Fluorescence Spectroscopy(XRF) and Instron measurement. The results showed that currently used sections of bailey bridge passed the strength verification and could be operated in drill of troops and battle fields.

• Journal of the Ergonomics Society of Korea
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• v.33 no.5
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• pp.313-321
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• 2014

Objective: The purpose of this study is to develop products that prevent muscular skeletal disease of farm workers, which would bring improvement for an efficient harvesting work. Background: A pretest for product development and a survey research was carried out to inspect the problems of current harvesting work procedure. The product was developed and assessed based on ideas to supplement and improve these weak points. Method: A total of twenty men were recruited to evaluate the effects of harvest baskets on the upper-limb muscle activity, working hours. For the usability evaluation, electromyogram and working hours of previous working method (disuse of harvest basket, one-hand carriage of the basket) and new working method with the usage of newly-developed harvest basket was examined. The whole anterior deltoid, biceps brachii and erector spinae on both sides, which make a total of six muscle parts, were used for this experiment. The results were analyzed using ANOVA with muscle activity (%MVC) of each three forms of work and required work time from SPSS 18.0. Results: According to the test result, all muscles did not demonstrate any statistically significant difference, with an exception of the backbone erector (right). The muscle activity of backbone erector (right) in the work method that uses the harvest basket developed in this study was detected to be approximately 23% less than that of the previous working method. Moreover, compared to the previous working method, the required work time decreased to a statistically significant degree. Conclusion: As such, the decrease in the amount of waist muscle usage at harvesting work would enable the prevention of muscular skeletal disease and stabilization of lumbar spine. Application: Which in turn would increase the effectiveness and reduce personnel expense (labor costs) while enhancing productivity with a decreased working hours.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2010.05a
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• pp.18-18
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• 2010

Glucosinolates(GSLs) are major secondary products($\beta$-thioglucoside N-hydroxysulfates) containing sulfates that are found mainly in Cruciferae family such as cabbage, broccoli, radish, turnip, kale, mustard and rapeseed as the important crops in agronomic and economic aspects. Especially, isothiocyanates(ITCs) have been shown to inhibit carcinogenesis with regulation cancer cell development followed by regulating target enzymes, inducing cell cycle arrest and apoptosis against various human cancer cell lines. Total desulfo(DS)-GSLs of nine type in 210 Korean leaf mustard accessions were isolated and confirmed using electrospray ionization mass spectrometric(ESI-MS/MS) method and DS-GSLs powerful library maked from several reference data. The isolated individual DS-GSLs were identified by removed $\beta$-D-glucopyranose residue ($C_6H_{11}O_5$, MW 163) from MS/MS data. Among them sinigrin(41.7%), glucoiberverin(21.7%) and gluconasturtiin(12.6%) were major components, Especially, despite gluconapin was minor component, accession K046197-1 and K046197-2 showed higher content of 4.11 and 3.31 mg/g(DW), respectively. The total GSLs contents in 210 accessions were ranged from 5.3 to 23.2 mg/g(DW) with a mean value of 13.0 mg/g(DW). As a result of principal component analysis(PCA), the individual GSLs loading plots were composed of three groups and components belonged to each group showed correlationship in quantitative pattern.

• Journal of the Ergonomics Society of Korea
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• v.32 no.6
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• pp.495-501
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• 2013

Objective: The purpose of this study was to survey of the subjective health status of the elderly farmer. Background: With increase of aged population, the health of the elderly farmer has become main concerns of the elderly in the rural community. For the effects of the factors related to quality of life, subjective health condition showed the largest influence. Method: The survey was conducted by 326 elderly farmers aged 50 and older in rural areas through structured questionnaires. Survey questionnaire consisted items of general characteristics, health-related life habits, levels of stress(SF-PWI), symptom of musculoskeletal diseases and general level of health(SF-36). For the data analysis, SPSS 19.0K was used, and analysis was conducted by using frequency, percentage, mean, and standard deviation. For the symptom prevalence of musculoskeletal disorders and comparison of average level of health, chi-square test and t-test were used. Results: The results of the study are as follows. It was shown that the symptom prevalence of musculoskeletal disorders had a significant difference in gender (p<0.01). Frequency analysis on presence of musculoskeletal symptoms in each part of body showed that leg/knee region was 28.1%, back region was 26.6%, shoulder region was 18.0%, arm/elbow region was 11.9%, hand/wrist region was 8.2% and neck region was 7.2%. According to comparison of average level of health, a social functioning were the highest as score 87.3, followed by mental health(65.6) and role limitation-emotional(65.5). Conclusion: Health promotion program for the elderly and female in the rural are needed. Application: The survey of the subjective health status of the elderly should be used for planning factors to make a health improvement plan in elderly farmer.

• The Plant Pathology Journal
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• v.25 no.3
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• pp.299-301
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• 2009

Powdery mildew symptoms were frequently on plants of goat's-beard (Aruncus dioicus var. kamtschaticus) found cultivated in the island Ulleungdo in June 2008. The symptoms appeared as powdery mycelial colonies and dark brown cleistothecia on leaves, petioles, stems and budding flowers of the plant. Incidence of the disease was as high as 50-80% in the goat's-beard fields. Specimens of the diseased plants were collected and examined for morphological characteristics of the causal fungus. On the basis of morphological characteristics of the conidial stage and the teleomorph, the fungus was identified as Podosphaera ferruginea. This is the first report of goat's-beard powdery mildew caused by Podosphaera ferruginea in Korea.

• Archives of Pharmacal Research
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• v.27 no.11
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• pp.1109-1113
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• 2004

A new triterpene (1) and six known pentacyclic terpenoids (2-7) were isolated from the methanol extract of the dried leaves from Mallotus apelta. Based on the spectral and chemical evidence, their structures were determined to be 3$\alpha$-hydroxyhop-22(29)-ene (1), hennadiol (2), friedelin (3), friedelanol (4), epifriedelanol (5), taraxerone (6), and epitaraxerol (7).

• Journal of the Optical Society of Korea
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• v.20 no.6
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• pp.762-769
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• 2016

The dynamic modulation transfer function (MTF) for image degradation caused by sinusoidal vibration is formulated based on a Bessel function of the first kind. The presented method makes it possible to obtain an analytical MTF expression derived for arbitrary frequency sinusoidal vibration. The error obtained by the use of finite order sum approximations instead of infinite sums is investigated in detail. Dynamic MTF exhibits a stronger random behavior for low frequency vibration than high frequency vibration. The calculated MTFs agree well with the measured MTFs with the slant edge method in imaging experiments. With the proposed formula, allowable amplitudes of any frequency vibration are easily calculated. This is practical for the analysis and design of the line-of-sight stabilization system in the remote sensing camera.