• Korean Journal of Soil Science and Fertilizer
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• v.42 no.2
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• pp.98-102
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• 2009

Various physical properties of soils were investigated in the areas where organic farming had been practiced widely, for upland fields. The investigations were also conducted in the nearby fields under conventional to find out the influence of organic farming on the physical properties of soils. The investigated properties involved bulk density, hardness, shearing resistance, friction resistance, sinking depth of small rectangular board, water stable aggregates and the depth of soil available to plants. By and large, the practice of organic farming tended to improve all of the physical properties soils, investigated in upland soils. However, in case of water stable soil aggregates in upland soils, the reverse was previous data; in those soils water stable soil aggregates were less under organic farming. It was suspected that this might be due to intensive application of the organic materials with high C/N ratio like wood chips and wood bark. The contents of OM, Av. P2O5, and Ex. cations were higher in organic farming than those of nearby fields under conventional, due to heavy organic matter application. From the results, It could be concluded that soils under organic farming were looser and softer than those under conventional as shown by lower bulk density and hardness, but that the effect of organic farming on water stable aggregates were low.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.382-391
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• 2002

This study is devoted to the problems of thermal and shrinkage stresses in order to avoid cracking at early ages. The early-age damage induced by volume change has great influence on the long-term structural performance of the concrete structures such as its durability and serviceability To solve this complex problem, the computer programs for analysis of thermal and shrinkage stresses were developed. In these procedures, numerous material models are needed and the realistic numerical models have been developed and validated by comparison with relevant experimental results in order to solve practical problems. A framework has been established for formulation of material models and analysis with 3-D finite element method. After the analysis of the temperature, moisture and degree of hydration field in hardening concrete structure, the stress development is determined by incremental structural formulation derived from the principle of virtual work. In this study, the stress development is related to thermal and shrinkage deformation, and resulting stress relaxation due to the effect of early-age creep. From the experimental and numerical results it is found that the early-age creep p)ays important role in evaluating the accurate stress state. The developed analysis program can be efficiently utilized as a useful tool to evaluate the thermal and shrinkage stresses and to find measures for avoiding detrimental cracking of concrete structures at early ages.

• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.237-243
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• 2006

The aims of this study was to investigate the clinical and radiographic features of temporomandibular dysfunction in the patients with RA to elucidate whether the RA patients would be a risk group for TMD. The 35 patients with temporomandibular joint dysfunction were included for this study, of which 15 had rheumatoid arthritis diagnosed by a rheumatologist, and other 20 was control group and they didn't have any history or clinical signs related to it. Clinical symptoms and signs of temporomandibular joint disorders, radiographic and MRI findings of temporomandibular joint were investigated. The results were compared between two groups. In RA group bilateral pain, morning stiffness, reduced opening range, and crepitations were more frequently reported than control group. Radiologic findings such as sclerosis and flattening of condylar head, marginal proliferation, and erosion of glenoid fossa were more frequently observed in RA group than control group. Disk destruction, cortical bone erosion, and intraarticular enhancement were more prominenet in RA group. From theses results, it can be concluded that many RA patients will develop TMD symptoms and the structural changes of TMJ is more extensive than the usual TMD cases.

• Journal of Sericultural and Entomological Science
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• v.3
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• pp.13-21
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• 1963

1. In the mulberry groves for both rearing of spring and fall, the rate of germination was 74.3 percent and the rate of the unfinished bud was 25.7 percent. 2. When the summer pruning after spring rearing was not worked, new sprouted leaves from the axillary buds of an age old branches was 74.88 percent of germination and the rest from unfinished bud during the spring showed 28.12 percent. 3. In the furrows running from north to south, new buds facing the due north were the worst but towards south-east and north-east were the best in their sprouts. 4. One year-old branches which had been raised without the summer pruning in the bush types of Morus Lhou (ser) Koidz offered a habitat where Apriona Rugico1lis Cherr could live. 5. On the grove of Morus Lhou Koidz cultivated at lower zone under a higher humidity and the shortage of sun light the appearance of Anomoneura Mori Schw was likely to happen very much. 6. One year old branches without the summer pruning produced more leaves owing to a long period of growth than branches with the summer pruning in the fall crops. 7. It is necessary to reconsider a certain distance of planting because of causing, when the summer pruning was not made in the bush plantation, a obstacle of fertilizer operation or the forth coming year's management. 8. It can not be thought the ideal method for us to raise mulberry tree such as Morus Lhou Koidz under natural form and at a short distance of planting (one another). 9. Among the species, Morus alba L. had a great deal of leaves and of the rate of germination per unit length of branch.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.567-575
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• 2018

The soil physical quality is a core factor in achieving two of sustainable agriculture's goals: productivity and environment. The purpose of this study was to assess changes in soil physical properties for nearly a decade through periodic monitoring of three cultivation types: upland, orchard, and paddy. Field surveys and lab analysis were conducted to determine the soils physical properties after every 4 years; upland (2009, 2013, and 2017), orchard (2010 and 2014), and paddy (2011 and 2015). In each year soil samples from 162-338 sites were collected. The bulk density of upland subsoil decreased from $1.53Mg\;m^{-3}$ to $1.50Mg\;m^{-3}$ while the plowing depth and subsoil organic matter increased from 13.7 cm to 19.5 cm and from $12.6g\;kg^{-1}$ to $18.3g\;kg^{-1}$ respectively during the period 2009-2017. Plowing depth for orchard increased from 16.7 cm to 18.9 cm. However, organic matter content decreased from $15.9g\;kg^{-1}$ to $15.4g\;kg^{-1}$ during the 2010-2014 period. For paddy, plowing depth and subsoil organic matter decreased from 17.5 cm to 16.7 cm and from $17.5g\;kg^{-1}$ to $15.8g\;kg^{-1}$ respectively. The subsoil bulk density increased from $1.47Mg\;m^{-3}$ to $1.52Mg\;m^{-3}$ from 2011-2015. Excess ratio for soil physical standards increased from 16% to 22% in orchard, 56% to 62% in paddy, and decreased from 41% to 29% in upland. The overall soil physical quality had been ameliorated for upland, but degraded for paddy. Improved tillage practices and application of appropriate organic matter is necessary to enhance the quality of soils, especially in the paddy field.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.2
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• pp.129-136
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• 1991

Dry matter productivity at silage stage of two corn hybrids varying resistance to rice blackstreaked dwarf virus(RBSDV) and two sorghum hybrids varying growth duration was evaluated at six planting dates (Apr. 1, Apr. 15, Apr. 29, May 13, May 27, and June 10) in Kyongsan where RBSDV is prevalent.Corn was harvested 38-40 days after silking. For sorghum 1st-cut was made 19-22 days after heading and some regrowth (2nd-cut) on October 13. 1. Percent stand of both corn hybrids was over 91% at all planting dates, but that of sorghum ranged 37.2-80.3% depending on hybrids and planting dates. 2. The number of days from planting to emergence decreased as planting date delayed in both crops. The number of days from emergence to silking of both corn hybrids and a sorghum hybrid(P 956) decreased as planting date delayed, but that of the other sorghum hybrid(P 931) increased significantly after May 13 planting. 3. RBSDV infection rate of corn hybrids was highest at April 1 planting (Kwanganok 24.896, Jinjuok 63.0%) and decreased up to April 29 planting and then increased as planting date delayed. Sorghum was not infected by RBSDV at all. 4. EarfTotal dry matter ratio of corn ranged 30.6-47.9% and that of sorghum 3.1-30.7% depending on hybrids and planting dates. All the hybrids developed grain normally at all planting dates except a sorghum hybrid (P 931) which developed few grains after May 13 planting. 5. Crude (C) protein and C. fat contents were similar among all treatments. C. fiber content of P 931 was higher than that of both corn hybrids and P 956, but nitrogen free extract (NFE) was lower. C. fiber and NFE of both corn hybrids and 1st-cut sorghum were similar among the planting dates, but C. fiber and NFE of 2nd-cut of sorghum decreased and C. protein increased as planting date delayed due to plants were younger. 6. Dry matter (DM) yield of all hybrids decreased as planting date delayed except Jinjuok of which yield was highest at April 29 planting. DM yield of corn was similar to 1st-cut sorghum, but lower than total DM yield of sorghum at April 1 and 15 plantings where regrowth yield was high.

• Economic and Environmental Geology
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• v.37 no.5
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• pp.569-583
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• 2004

The rock properties of the West pagoda in the Gameunsaji temple site are composed mainly of dark grey porphyritic granodiorite with medium grained equigranular texture and developed with small numerous dioritic xenoliths. These xenoliths occurred with small holes due to different weathering processes. As a weathering results, the rock properties of this pagoda occur wholly softened to physical hardness because of a complex result of petrological, meteorological and biological causes. Southeastern part of the pagoda deteriorated seriously that the surface of rock blocks showed partially exfoliations, fractures, open cavities in course of granular decomposition of minerals, sea water spray and crystallization of salt from the eastern coast. The Joint between blocks has small or large fracture cross each other, contaminated and corrupted for inserting with concrete, cement mortar, rock fragments and iron plates, and partially accelerated coloration and fractures. There are serious contamination materials of algae, fungus, lichen and bryophytes on the margin and the surface on the roof stone of the pagoda, so it'll require conservation treatment biochemically for releasing vegetation inhabiting on the surface and the discontinuous plane of the blocks because of adding the weathering activity of stones and growing weeds naturally by soil processing on the fissure zone. Consisting rock for the conservation and restoration of the pagoda would be careful choice of new rock properties and epoxy to reinforce for the deterioration surfaces. For the attenuation of secondary contamination and surface humidity, the possible conservation treatments are needed.

• International Journal of Highway Engineering
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• v.12 no.2
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• pp.107-113
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• 2010

In this study, the relative effects of low-chloride deicier(LCD) and two other deicing agents on the scaling of concrete were conducted in a series of tests at laboratory accordance with the ASTM C 672. The solutions concentration of deicers tested included 1, 4, 10%. Tap water was used as control. The amount of scaling was evaluated gravimetrically. As test result of deicer solution types, when applied to 4% solutions, surface scaling of concrete after 56 freeze-thaw cycles was produced significantly as about 9 times on LCD solution, as about 18 times on $CaCl_2$ solution, and as about 33 times on NaCl solution comparing with tap water. As test result of deicer solution concentrations, relatively low concentrations (of the 4% by weight) of deicer were produced more surface scaling than higher concentrations (of the 10% by weight) or lower concentrations (of the 1% by weight) of deicer. It show that the damaging concentration is of the order of 3~4% for previous research result. It appears that the mechanism of surface scaling is primarily physical rather than chemical. Also, the effect of chloride deicier types, freeze-thaw cycling, and air contents on the performance of concrete was experimentally investigated. The results show that the concrete specimens subjected to freeze-thaw cycling scaled more severely in exposure to deicing salt than those in non-exposure to deicing salt, weight losses of the specimens tested in exposure to deicing salt were twice as much as those tested in non-exposure to deicing salt. Relative dynamic modulus of elasticity of concrete specimens decreased more quickly in exposure to deicing salt than in non-exposure to deicing salt. Also, relative dynamic modulus of elasticity of concrete specimens in exposure to sodium chloride deicing salt was decreased more quickly comparing with exposure to LCD salt. It is also shown that the chloride contents according to concrete specimen depths was more largely in exposure to LCD salt. When concrete specimen is exposed to chloride deicing salts and freeze-thaw cycling, performance degradation in the entrained air concrete(AE concrete) retarded more considerably comparing with non-entrained air concrete(Non-AE concrete).

• Journal of Korean Medicine for Obesity Research
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• v.14 no.2
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• pp.47-54
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• 2014

Objectives: This study is to confirm the effect of combined extract and individual extract of Samjunghwan (SJH) in anti-oxidative and anti-obesity effect. Methods: Combined ethanol extract of readily made SJH and individual ethanol extract of Atractylodes japonica, Cortex lycii radicis, and Morus alba Linne was combined after the extraction. To evaluate the anti-oxidative effect of SJH, total phenol compound and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging ability were conducted. Real-time quantitative-polymerase chain reaction analysis of transcription factor peroxisome proliferator-activated receptror ${\gamma}$ ($PPAR{\gamma}$), adenosine monophosphate-activated protein kinase (AMPK)-${\alpha}1$, tumor necrosis factor-${\alpha}$ ($TNF{\alpha}$) and 3-hydroxy-3-methylglutaryl CoA reducatase (HMG-CoA reductase) were done with 3T3-L1 cells to investigate the ant-obesity effect. Also, cell viability analysis were done to see to toxicity of SJH. Results: Individual extract of SJH showed significant decrease in $TNF{\alpha}$ and AMPK transcription while $PPAR{\gamma}$ showed significant increase. Combined extract and individual extract of SJH both showed decrease in HMG-CoA reductase. DPPH free radical scavenging ability and total phenol compound was analogous between two groups. Conclusions: Individual extract of SJH appears to be more effective in anti-oxidation and anti-obesity effect compared to combined extract of SJH.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.214-221
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• 2020

Salinity is one of the major abiotic stressors that inhibits the growth, yield, and productivity of crop plants. Therefore, it is necessary to develop crops with increased salt tolerance for cultivation in saline soils such as is found in reclaimed land. The objective of this study was to develop a salt-tolerant silage rice line that grows on reclaimed land. In order to develop this salt-tolerant silage rice, we transferred Saltol, a major QTL associated with salt tolerance, from IR64-Saltol, a salt-tolerant indica variety, into Mogyang, a susceptible elite japonica variety. To determine the effect of salt stress, Mogyang and IR64-Saltol cultivars were grown on a medium containing various concentrations of NaCl in in vitro conditions. Shoot length was found to decrease with increasing salt concentrations, and root growth was almost arrested at NaCl concentrations over 50 mM in the Mogyang cultivar. Based on these preliminary results, we screened five salt-tolerant lines showing superior growth under salt stress conditions. Polymerase chain reaction and sequencing results showed that the introgression types of Saltol QTL were derived from the IR64-Saltol cultivar in almost all selected lines. Based on the observed growth and physiological characteristics, the new Saltol introgression lines showed higher salt tolerance compared to the Mogyang parental cultivar. The salt-tolerant lines identified in this study could be used as a genetic resource to improve rice salt tolerance.