• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.11-18
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• 2020

Eggs are likely to be used in agriculture because they can provide enough nutrients for crop growth. Statistics show that a large number of eggs are lost due to breakage before reaching the final consumer. The purpose of this study was to make a natural liquid fertilizer as a substitute for chemical fertilizers using broken eggs as a resource and to evaluate the efficiency of the formulated fertilizer. To make the liquid fertilizer, the broken eggs and distilled water were mixed at ratios of 6 : 4 and 4 : 6. Then, effective micro-organisms (EM) and sugar were added, and the mixture was fermented. The temperature and electrical conductivity (EC) increased gradually with the fermentation while the pH decreased. When evaluated following the seed germination index method of the compost, it was found that the fertilizer matured 10 days after the beginning of the experiment. The growth experiment was conducted with lettuce in which the fermented liquid fertilizer was compared with a commercial liquid fertilizer. The 6 : 4 treatment produced plants with the densest fresh shoot and roots weighing 41.6 and 4.6 g, respectively. The number of leaves (12.3 per plant) was also the highest for the 6 : 4 treatment. Soil analysis showed that the soil pH was improved, and the soil organic matter was increased in the fermented liquid fertilizer treatment.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.266-266
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• 2017

In recent years, adoption of the System of Rice Intensification (SRI) is spreading in most Asian countries, and more recently in Cambodia is one of the Asian countries with high adoptions of SRI. We conducted on-farm experiment to investigate the effects of SRI on rice growth and yield in the farmers' fields in rainfed region of southern Cambodia. The study was undertaken in rainfed lowland fields of Popel commune ($11^{\circ}$ 04' 67" N, $104^{\circ}$ 40' 79" E) of Tram Kak District in Takeo Province during the wet seasons in 2012, 2013, and 2015. A total of 32 on-farm experiments were conducted during the wet seasons for three years of 2012 (11 fields), 2013 (8 fields), and 2015 (13 fields). Across the three years of study, SRI produced significantly greater plant biomass and grain yield than Non-SRI. The yield increase was mostly ascribed for the increased number of grains per land area, which was due to the increased number of spikelets per panicle rather than the number of panicles per land area. With no significant difference between SRI and Non-SRI with respect to seedling age, the greater number of grains per panicle was accounted for by the reduced planting density and increased amount of manure application in SRI than Non-SRI fields. It was found that the greater manure application has increased soil nitrogen content in SRI and Non-SRI fields. While SRI did not increase the number of panicles per land area, it did increase the number of panicles per hill.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.291-291
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• 2017

The effects of bioactivity, binding polyphenolic contents, DPPH radical scavenging activity, ABTS radical scavenging activity, xanthine oxidase and immune activity on the storage temperature and durations of Codonopsis lanceolata root were evaluated in vitro. The contents of total polyphenol and flavonoid content by storage temperature and storage period was no significant difference according to the storage period, but it was found that the content was higher at lower storage temperature. The DPPH free radical scavenging activity at six different concentrations, 500, 1000, 2500, 5000, 10000 and 20000 mg/L are measured, the scavenging activity according to different storage temperature and storage period showed relatively the higher the activity in the shorter storage period or the lower storage temperature. The ABTS radical scavenging activity did not show a significant difference under various storage temperature and storage period conditions. The xanthine oxidase inhibitory activity of C. lanceolata extract tended to decrease more, depending on the longer storage period or the higher storage temperature. In different storage period and storage temperature conditions, the immune cell growth of C. lanceolata extract promoted a concentration-dependent manner in both human T cell and B cell, and did not show a significant difference. These results of this study suggested that the root of C. lanceolata may assist in the potential biological activities, and can be used as a source of human health products.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.292-292
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• 2017

This study was conducted to evaluate the effect of anti-obesity and antioxidant enzyme activities in vitro by different solvent fractions from the roots of Codonopsis lanceolata. The cytotoxicity of different solvent fractions of C. lanceolata on 3T3-L1 preadipocytes were evaluated using the MTT assay, the rate of cell survival progressively decreased in a dose-dependent manner. Butyl alcohol fraction at $200{\mu}g/mL$ exhibited a pronounced cytotoxic effect (75.73%) on 3T3-L1 cell comparable to that of the hexane fraction (79.82%), methylene chloride fraction (84.02%), ethyl acetate fraction (87.62%) and DW fraction (86.30%) at the same concentration. The Oil Red O solution was used to determine whether different solvent fractions of C. lanceolata induce adipocyte differentiation in 3T3-L1 preadipocytes. Confluent 3T3-L1 cells were treated with $50{\mu}g/mL$ concentration of solvent fraction extracts from C. lanceolata. Inhibitory degree of lipid accumulation against solvent fraction extracts showed a significant level compared with the control. Both lipid accumulation and adipocyte differentiation showed relatively high effect on methyl chloride fraction. The root extract of C. lanceolata had the highest SOD enzyme activity of 84.5% in ethyl acetate partition layer and while water partition layer of diploid showed the lowest SOD enzyme activity of 57.9%. The activity of CAT, APX and POD showed a significantly higher activity in ethyl acetate partition layer compared with the other fraction. These results suggested that the roots of C. lanceolata may assist in the potential biological activity on anti-obesity and antioxidant capacity.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.354-354
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• 2017

Rice grain yield is determined by crop dry matter production that is sensitive to temperature. Our objective was to determine whether the difference in temperature between years had an impact on the relationship between yield components and grain yield. Field experiments were conducted under machine transplanting cultivation by using yield data of two japonica rice varieties, Odaebyeo (early maturing) and Nampyeong (mid-late maturing), in 2013 to 2016 in Suwon, Korea. Plant height, dry weight, and yield components were examined by analysis of variance, correlation. The milled rice yield of the two varieties were the highest in 2016, however the lowest yields were observed in the different years. In 2016, Odaebyeo produced $0.96t\;ha^{-1}$ greater milled rice yield than in 2015, and Nampyeong produced $1.11t\;ha^{-1}$ greater yield than in 2013. The correlation analysis indicated that spikelet per panicle (R = 0.53) was associated with grain yield of Odaebyeo. In Nampyeong, biomass at heading date (R = 0.74), 1000-grain weight (R = 0.71), spikelet per panicle (R = 0.58), and panicle number per $m^2$ were associated with grain yield. Sink size (spikelet number per $m^2$) of the two varieties responded to accumulative temperature from transplanting to panicle initiation stage. In this experiment, optimal accumulative temperature before panicle initiation has effect on increased spikelet number and/or number of panicle that were mainly responsible for yield difference. Rice production research to increase grain yield should consider all yield components, but increased emphasis on biomass production before heading is also necessary as well as grain ripening conditions.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.2
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• pp.147-153
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• 2013

Recently the primary water stress corrosion cracking(PWSCC) has occurred in the dissimilar metal weld region between pressurizer nozzle and safe-end in nuclear power plants(NPPs). As material of the pressurizer nozzle, SA508 Gr. 3 low alloy steel was used. F316L stainless steel and Alloy 82/182 were used as safe-end and weld metal, respectively. Although mechanical properties are needed for evaluation of the structural integrity against flaw in the material, material specification and standard don't supply those properties. Therefore, the present study conducted tensile and fracture toughness tests on SA508 Gr.3 and F316L stainless steel at ambient temperature and operating temperature of NPPs and reported the tested results.

• Journal of Korean Society on Water Environment
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• v.21 no.1
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• pp.7-13
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• 2005

With the appearance of pathogenic microorganisms, which were resistant to free chlorine, the significant attention to the necessity of powerful alternative disinfection methods such as ozone, chlorine dioxide, LTV irradiation to inactivating pathogens has been increased in water treatment. Among these alternative disinfection methods, ozone is well known as strong biocidal method and the usage of ozone is also increasing in Korea. However, in Korea, there has been no report on the quantitative study of Cryptosporidium parvum with ozone and its evaluation in advanced drinking water treatments. This study reports on the methodology for predicting the ozone inactivation of Cryptosporidium parvum by ozone disinfection in advanced drinking water treatment. The method is based on the fact that a specific inactivation level of microorganisms is achieved at a unique value of ozone exposures, independent of ozone dose and type of water, and quantitatively described by a delayed Chick-Watson model. The required values ${\bar{C}}T$ for 2 log inactivation of Cryptosporidium parvum was $6.0mg/L{\cdot}min$ and $15.5mg/L{\cdot}min$ at $20^{\circ}C$ and $5^{\circ}C$, respectively. From this obtained Cryptosporidium parvum inactivation curves and calculated ${\bar{C}}T$ values of advanced drinking water treatment water in Korea with FIA (Flow injection alaysis), we can predict that water treatment plant can achieve a 1.1~1.8 log inactivation and 0~0.4 log inactivation at $20^{\circ}C$ and $5^{\circ}C$, respectively. This methodology will be useful for drinking water treatment plants which intend to evaluate the disinfection efficiencies of their ozonation process without full scale test and direct experiments with Cryptosporidium parvum.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.3
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• pp.391-398
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• 2011

This study is to develop highly efficient coagulation system(HECS) that runs treatment with a short retention time to cover the overflow in the rain, which coagulation, mixing and settling are contacted in a single reactor and to estimate the applicability. Setting up 100ton/day-size pilot scale plant, the results of continuous operation in case of runoff, maintaining 20 minute-retention time at optimum chemical injection condition(Alum 100mg/L, Polymer 1.0mg/L) shows the highest removal efficiency(Turbidity 93.1%, TCODcr 80.6%, BOD 81.8%, SS 92.5%, TN 72.3% and T-P 87.3%). It was estimated that the large amount of cost for separate sewage system and the size of area for system instruction can be reduced if the HECS is applied for CSOs treatment because the HECS is so compact and quickly. When we see the results, HECS from this study could be able to treat the pollutant quickly within a short retention time only with coagulant and polymer, which could show high applicability.

• Journal of the Korean Wood Science and Technology
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• v.42 no.5
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• pp.543-554
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• 2014

Natural plant extract has been the subject of intense research aiming in elucidating the underlying mechanisms of their chemopreventive effects upon various forms of human cancers. The objective of our study was to evaluate the natural antioxidants and anticancer agent potential of Phyllostachys. The chemical composition of steam extract from Phyllostachys was carried out using GC-MS. The steam extract of Phyllostachys was dominated by monoterpenes (62.96% - 71.36%) and sesquiterpenes (23.58% - 33.13%) as the main compounds. The antioxidant activities of the steam extract was determined using a DPPH scavenging and hydrogen peroxide scavenging activity test systems. Furthermore, the amounts of total phenolics in steam extract were determined spectrometrically The steam extract of P. pubescens and P. bambusoides were presented the high activity (69.4% and 64.0%, respectively.). The steam extract from Pyllostachys species showed a hydrogen peroxide scavenging activity of approximately 50.4% - 54.6% when compared to that of the standard gallic acid. The anticancer activities of steam extract were determined using a MTT assay. Assessment of the cytotoxic effect of the steam extract on PC-3 cells showed that the P. bambusoides (20.85%) and P. pubescens (20.41%) were superior in induced cytotoxicity compared with the steam extract of P. nigra var. henonis (1.15%). Findings from this study indicated that steam extract of P. bambusoides and P. pubescens possessed potential as medicinal drug especially in prostate cancer treatment.

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.17-22
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• 2009

Thermal stress and elastic creeping stress analysis was conducted by finite element method to simulate start-up process of a boiler header of 500MW standard fossil power plant. Start-up temperature and operating pressure history were simplified from the real field data and they were used for the thermal stress analysis. Two kinds of thermal stress analysis were considered. In the first case only temperature increase was considered and in the second case both of temperature and operating pressure histories were considered. In the first analysis peak stress was occurred during the temperature increase from the room temperature. Hence cracking or fracture may occur at the temperature far below the operating maximum temperature. In the results of the second analysis von Mises stress appeared to be higher after the second temperature increase. This is due to internal pressure increase not due to the thermal stress. When the stress components of radial(r), hoop($\theta$) and longitudinal(z) stress were investigated, compression hoop stress was occurred at inner surface of the stub tube when the temperature increased from room temperature to elevated temperature. Then it was changed to tension hoop stress and increased because of the operating pressure. It was expected that frequent start-up and shut-down operations could cause thermal fatigue damage and cracking at the stub tube hole in the header. Elastic-creeping analysis was also carried out to investigate the stress relaxation due to creep and stabilized stress after considerable elapsed time. The results could be used for assessing the creep damage and the residual life of the boiler header during the long-tenn service.