• Journal of Radiation Protection and Research
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• v.42 no.1
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• pp.42-47
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• 2017

Background: One of the most urgent issues following the accident at the Fukushima Daiichi nuclear power plant (FDNPP) was the remediation of the land, in particular, for residential area contaminated by the radioactive materials discharged. In this study, the effect of decontamination on reduction of ambient dose equivalent outdoors and indoors was evaluated. The latter is essential for residents as most individuals spend a large portion of their time indoors. Materials and Methods: From December 2012 to November 2014, thirty-seven Japanese single-family detached wooden houses were investigated before and after decontamination in evacuation zones. Outdoor and indoor dose measurements (n = 84 and 114, respectively) were collected based on in situ measurements using the NaI (Tl) scintillation surveymeter. Results and Discussion: The outdoor ambient dose equivalents [$H^*(10)_{out}$] ranged from 0.61 to $3.71{\mu}Sv\;h^{-1}$ and from 0.23 to $1.32{\mu}Sv\;h^{-1}$ before and after decontamination, respectively. The indoor ambient dose equivalents [$H^*(10)_{in}$] ranged from 0.29 to $2.53{\mu}Sv\;h^{-1}$ and from 0.16 to $1.22{\mu}Sv\;h^{-1}$ before and after decontamination, respectively. The values of reduction efficiency (RE), defined as the ratio by which the radiation dose has been reduced via decontamination, were evaluated as $0.47{\pm}0.13$, $0.51{\pm}0.13$, and $0.58{\pm}0.08$ ($average{\pm}{\sigma}$) when $H^*(10)_{out}$ < $1.0{\mu}Sv\;h^{-1}$, $1.0{\mu}Sv\;h^{-1}$ < $H^*(10)_{out}$ < $2.0{\mu}Sv\;h^{-1}$, and $2.0{\mu}Sv\;h^{-1}$ < $H^*(10)_{out}$, respectively, indicating the values of RE increased as $H^*(10)_{out}$ increased. It was found that the values of RE were $0.53{\pm}0.12$ outdoors and $0.41{\pm}0.09$ indoors, respectively, indicating RE was larger outdoors than indoors. Conclusion: Indoor dose is essential as most individuals spend a large portion of their time indoors. The difference between outdoors and indoors should be considered carefully in order to estimate residents' exposure dose before their returning home.

• Korean Journal of Weed Science
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• v.16 no.3
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• pp.194-199
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• 1996

Seed size and days required to reach specific growth stages were determined for Echinochloa crus-galli (L.) P. Beauv. varieties which are major grass species found in Korean paddy field and the results were compared with E. frumentacea (Roxb.) Link. In addition, responses of the Echinochloa species on preemergence herbicides (molinate, esprocarb, and mefenacet) were investigated with respect to time of application. One thousand seed weight of E. crus-galli var. oryzicola was about 3 times heavier than that of var. praticola, but was not significantly different that of E. frumentacea. Days requited to reach the 2.5 leaf-stage (LS) were 11, 13, and 14 days after seeding for E. frumentacea, E. crus-galli var. oryzicola, and E. crus-galli var. praticola, respectively. E. crus-galli var. praticola was more sensitive to molinate, esprocarb and mefenacet than var. oryzicola and the sensitivity of both the varieties decreased as the time of application LS was delayed. However, there was no great difference in the response for E. frumentacea when applied between 1.5 and 3.0 LS. In thiocarbamate hebicides esprocarb was more active to Echinochloa species than molinate and the higher the active ingredient of the herbicides, the greater was the activity to Echinochloa species. Differential susceptibility of Echinochloa species to the herbicides was not related to the seed size, but to the early growth stages at the time of herbicide application which were affected by the seed size.

• Korean Journal of Weed Science
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• v.16 no.3
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• pp.237-244
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• 1996

Propanil [N-(3,4-dichlorophenyl) propanamide] which was applied at 4,200g ai/hapostemergence 7 days after seeding or transplanting, completely reduced the growth of shoot and root of barnyardgrass at 100% under dry condition while plant height, root length and shoot fresh weight of barnyardgrass at 63, 40 and 78%, respectively under water condition. On the other hand, the herbicide did not affect the growth of shoot and root of rice grown under water condition and transplanting condition, but reduced the plant height, root length and shoot fresh weight of broadcast rice on soil at 24, 18 and 28%, respectively, under dry condition. Microscopically, the epidermal cells of treated-barnyardgrasses under both conditions were severely constricted, chloroplasts in the cells of vascular bunble sheath were partially lacked, and mesophyll cells were often ruptured, whereas those of treated-rice were not affected. Histological observations showed that propanil reduced the thickness of leaf blade of barnyardgrass under both conditions at 36-48% due to mainly reduction and constriction of mesophyll cell, while it did not affect or even increased the thickness of leaves of rice under all conditions compared to control. These results indicate that broadcast rice on soil were more injured than drilled rice in soil under dry condition, however, in the other tested conditions ricer were not affected.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.439-445
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• 2004

Diffusion tensor image(DTI) exploits the random diffusional motion of water molecules. This method is useful for the characterization of the architecture of tissues. In some tissues, such as muscle or cerebral white matter, cellular arrangement shows a strongly preferred direction of water diffusion, i.e., the diffusion is anisotropic. The degree of anisotropy is often represented using diffusion anisotropy indices (relative anisotropy(RA), fractional anisotropy(FA), volume ratio(VR)). In this study, FA images were obtained using different gradient schemes(N=6, 11, 23, 35. 47). Mean values and the standard deviations of FA were then measured at several anatomic locations for each scheme. The results showed that both mean values and the standard deviations of FA were decreased as the number of gradient directions were increased. Also, the standard error of ADC measurement decreased as the number of diffusion gradient directions increased. In conclusion, different gradient schemes showed a significantly different noise performance and the schem with more gradient directions clearly improved the quality of the FA images. But considering acquisition time of image and standard deviation of FA, 23 gradient directions is clinically optimal.

• Restorative Dentistry and Endodontics
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• v.31 no.4
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• pp.290-299
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• 2006

Objectives: The purpose of this study is to evaluate the effect of ethylene glycol analogs on modulus of elasticity and ultimate tensile strength of moist, demineralized dentin matrix. Methods: Dentin disks 0.5 mrn thick were prepared from mid-coronal dentin of extracted. unerupted, human third molars. 'I' beam and hour-glass shaped specimens were prepared from the disks, the ends protected with nail varnish and the central regions completely demineralized in 0.5M EDTA for 5 days. Ultimate tensile stress (UTS) and low strain modulus of elasticity (E) were determined with specimens immersed for 60 min in distilled water $(H_{2}O)$, ethylene glycol $(HO-CH_{2}-CH_{2}-OH)$, 2-methoxyethanol $(H_{3}CO-CH_{2}-CH_{2}-OH)$, and 1,2-dimethoxyethane $(H_{3}CO-CH_{2}-CH_{3}-OCH_{3})$ prior to testing in those same media. Modulus of elasticity was measured on the same specimens in a repeated measures experimental design. The results were analyzed with a one-way ANOVA on ranks, followed by Dunn's test at ${\alpha}\;=\;0.05$. Regression analysis examined the relationship between UTS or E and hoy's solubility parameter for hydrogen bonding $({\delta}_{h})$ of each solvent. Results: The UTS of demineralized dentin in water, ethylene glycol, 2-methoxyethanol, and 1,2-dimethoxyethane was 24 (3), 30 (5), 37 (6), and 45 (6) MPa, ${\times}$ (SD) N = 10. Low strain E for the same media were 16 (13), 23 (14), 52 (24), and 62 (22) MPa. Regression analysis of UTS vs ${\delta}_{h}$ revealed a significant $(p\;<\;0.0001,\;r\;=\;-0.99,\;R^{2}\;=\;0.98)$ inverse, exponential relationship. A similar inverse relationship was obtained between low strain E vs ${\delta}_{h}\;(p\;<\;0.0005,\;r\;=\;-0.93,\;R^{2}\;=\;0.86)$. Significance: The tensile properties of demineralized dentin are dependent upon the hydrogen bonding ability of polar solvents $({\delta}_{h})$. Solvents with low ${\delta}_{h}$ values may permit new interpeptide H-bonding in collagen that increases its tensile properties. Solvents with high ${\delta}_{h}$ values prevent the development of these new interpeptide H-bonds.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.1
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• pp.31-38
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• 2012

This study was conducted for the purpose of pursuing the development of Korean scenic spots1) by comparing policies of preserving and maintaining scenic spots in Northeast Asia, especially in South Korea, Japan, Taiwan, China. The objects to be compared for this study were the concepts and designation criteria of scenic spots, the types and present conditions of designated scenic spots and the preservation policies and budgets for scenic spots and so on. As for the research methods, analyses of literary documents, domestic and oversea on-site surveys and mutually-comparative analyses of translated data from China, Taiwan and Japan, etc. were used for this study, and the main results obtained by those research methods can be summarized as blow. As for the present conditions of designated scenic spots, it was found that there were more natural scenic spots than natural ones in Korea, Taiwan and China, while there were more cultural heritages designated as scenic spots than natural heritages in Japan. With Tourism Development Ordinance additionally enacted, which involves the contents related to the permission of tourism development and investment for scenic spots, the Taiwanese government tries to activate tourist attractions by attracting private enterprises' investments. What is unique about Japan is that some places can be pre-designated as scenic spots through an education committee called 'Scenic Spot Designation Committee'. The study of the book was investigation analysis with the designated present situation and the actual situation of the northeastern Asian national natural beauty spot. The type of Korea natural beauty spot resources and the appointment. I was going to offer it with a basic document to expect a designated standard and the designated activation of the Korea natural beauty spot.

• Journal of Korean Society of Forest Science
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• v.101 no.1
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• pp.113-120
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• 2012

The purpose of this study was to find out the effect of a torrent control structure using customized tetrapods on the forest water quality, fishes, snials and streamwater ecology conservation and management. The study was conducted in the Honggye valley located in Sanchung-gun, Gyungsangnam-do, and stream water quality and streamwater ecology was compared before and during 2 years after construction of torrent control structure. After construction of the torrent control structure using customized tetrapods, pH of stream water didn't get out of the range of River water quality standard class I. After 2 years construction of the torrent control structure using customized tetrapods, Dissolved Oxygen concentration didn't change, and Electrical Conductivity measurements agreed well within the range of normal clean stream water quality. After construction of the torrent control structure using customized tetrapods, fishes and snials up and down stream movement didn't influence of the tetrapods dam. Stream water quality during 2 years after construction of the torrent control structure was similar to before construction. Therefore, it was find out that the torrent control structure didn't affect stream water quality and ecology.

• Korean Journal of Weed Science
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• v.7 no.2
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• pp.200-207
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• 1987

This study was conducted to select and develop herbicide resistant plant through tissue culture. Growth response of seedlings and callis of various rice varieties with Echinochloa species was assessed under the treatment of various rates of butachlor [N-(butoxy methyl)-2-chloro-2', 6'-diethyl acetamide] and simetryne [2,4-bis(ethyl amino)-6-methyl thio-1,3,5-triazine]. Further, succinate dehydrogenase activity was determined in herbicide treated callus to characterize different response of plants to herbicide. Rice variety like Sangpung showed relative resistance in both callus and seedling states against butachlor, indicating maintenance of resistance. However, in the simetryne treatment, the similar response was not observed in callus and seedling state, although there was a great different response among plant materials against simetryne. Rice variety which exhibited resistance in callus and seedling states showed low succinate dehydrogenase inhibition index. Succinate dehydrogenase inhibition index can be used as an important marker characters to differentiate varietal response of plant to herbicide. Rice plant was differentiated from butachlor and simetryne tolerant callus treated at $2.5{\times}10^{-5}$ M is growing under the growth chamber and can be used for resistant source.

• Korean Journal of Weed Science
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• v.5 no.1
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• pp.56-62
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• 1985

Effects of butachlor [N-(butoxymethyl)-2-chloro-2', 6'-diethyl acetanilide] and 1,8-naphthalic anhydride (NA) on post-germination growth, mesocotyl and root anatomy and root-cell membrane permeability of rice (Orvza saliva L.) were investigated. Lengths of mesocotyl and radicle were markedly decreased as the application rates of butachlor increased from 0.1 to 100 ppmW and NA from 1 to 100 ppmW, but there was no effect on coleoptile elongation. Application of butachlor-NA resulted in increase in coleoptile elongation, but decrease in mesocotyl elongation. Partial breakdown of cortical cells in root and mesocotyl was caused by either trutachlor or NA treatments, resulting in increase in intercellular air space. Further increase in the intercellular air space of root and mesocotyl was obtained when butachlor was applied in combination with NA. Increase in root-cell membrane permeability occurred when either butachlor or NA was applied. However, butachlor-NA treatments resulted in reduction in the permeability.

• Parasites, Hosts and Diseases
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• v.25 no.2
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• pp.129-140
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• 1987

The present study was undertaken to demonstrate the surface structure of Paragonimus westermani metacercaria in Korea with special reference to the distribution of sensory papillae. Metacercariae were isolated from crayfish, one of the second intermediate tost of P. westermani in Bogil island, Chollanam-do (Province), Korea, where has been known as an endemic area of human paragonimiasis. Isolated metacercariae were encysted and examined with light. scanning and transmission electron microscopes for morphological features. On the surface of iBetacercariae, three types of sensory FaFillae were identified. Large domed papillae ($3~5{\mu\textrm{m}}$), which were covered with wrinkled plasma n!embrane of the worm, were distributed on the oral and ventral suckers only. On the oral sucker, these large domed papillae were 12~13 in number. On the other hand large domed papillae on the ventral sucker were constantly 6 in number and hexagonal in distribution. Small domed papillae ($2~3{\mu\textrm{m}}$), of which surface was more smooth than those of large ones, were distributed symmetrically on the ventral (30~32 pairs) and dorsal surfaces (40~42 Pairs). Ciliated Papillae ($0.8~1.5{\mu\textrm{m}}$) were observed about 5~6 in number around the oral sucker and 3~5 pairs each on the ventral and dorsal surface of the body. Single Fcinted spines covered the entire surface of the body except around the excretory pore. Spines on the anterior fart of the body were 0.9~2.0${\mu\textrm{m}}$ in length and $45~55/100{\mu\textrm{m}}$2 in number, and were gradually reduced in length ($0.4~1.4{\mu\textrm{m}}$) and in nuns.her ($12~27/100{\mu\textrm{m}}$2) toward the posterior part. The body wall of p. westermoni metacercariae was consisted with anucleated syncytium layer, fibrous interstitial layer and musclar layer. In the anucleated syncytium, biconcave ($0.15~0.55{\mu\textrm{m}}$) and spherical ($0.08~0.16{\mu\textrm{m}}$) secretory granules, which were transferred from epidermal cells via protoplasmic tubules, mitochondria and rihoEorses, T-ere observed. Spines originated around the basement membrane protruded externally. Epidermal cells were consisted with a nucleus and a cytoplasm, and connected to syncytium with protoplasmic tubules. In the cytoplasm many secretory granules, mitochondria, Golgi complex, endoplasmic reticula, ribosomes and lipid droplets were observed.