• Journal of the Korean Society for Nondestructive Testing
• /
• v.30 no.4
• /
• pp.386-395
• /
• 2010

The steam generator management program(SGMP) has recently defined the procedures for the qualification of eddy current hardware and technique. These procedures provide two basic methods for qualification. The first way is to qualify the equipment or the probe by using the flaw mechanism and method of the pulled tubes from the heat exchangers or the artificial flawed tubes. The second way is to verify the equivalency with the characteristics of the qualified equipment or probe. In this case, the qualified equipment or probe may be modified to substitute or replace instruments or probes without re-qualification provided that the range of essential variables defined in the examination technique specification sheet are met. This study is to describe the result of the comparative performance evaluation of bobbin coil eddy current probes manufactured by KEPCO Research Institute and probes manufactured by a foreign manufacturer. As a result of this study, although there were minor differences between the two kinds of probes, it was evaluated that the two kinds of probes were almost identical in the significant performance characteristics described in the KEPCO Research Institute guideline.

• Korean Journal of Organic Agriculture
• /
• v.25 no.2
• /
• pp.445-460
• /
• 2017

This study was carried out for three years from 2013 to 2015 to investigate the actual condition of pest control of domestic persimmon organically cultivated farmers, to select environment - friendly pest control materials for major pests, and to conduct field test of established control system. The main cultivated cultivar of the reader farmer of organic cultivation was "Buyou" and sprayed organic agricultural material 9~17 times per year for pest control. The most harmful pests were anthracnose, bugs, persimmon fruit worm, and scales, etc. The control materials used were organic lime sulfur mixture, red clay sulfur, emulsifier, bordeaux solution, and self-made plant extracts using garlic, ginkgo nut and pine tree. The effective materials for controlling anthrax were lime sulfur mixture and red clay sulfur. Garlic oil + citronella emulsion, shrubby sophora seed extract + tea extract was effective to control Riptortus clavatus and Euproctis subflava. When installed 60 ea per 10a of mating disruption trap in a sweet orchard, the fruit setting rate was improved by 30%. The results of field test of control system to control 10 times a year in organically grown persimmons were able to harvest fruit of 70.7%. However, since any kinds of pesticides can not be sprayed during the harvest season in September and October, the damaged by bugs did not decreased, and further research is needed.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.63 no.2
• /
• pp.120-130
• /
• 2018

Improvement in rice grain yield has been approached by means of genetic amendment, cultural management, and environmental adaptation. Subjecting the plant during the grain filling period to an appropriate environment plays a key role in achieving a high grain yield in temperate rice. Field experiments were conducted for two consecutive years with two planting times to assess the relations among grain filling traits, loss of leaf activity during the ripening period, and the grain yield of temperate japonica rice with wide environmental variation. Higher grain yields were attained in 2017 than in 2016 and with late planting than with early planting. The high grain yield accompanied a comparatively lesser increase in grain weight at the early filling stage but more gain in grain weight occurred during the late filling stage. Final grain weight correlated positively with grain filling duration but negatively with grain filling rate. Extended grain filling duration was associated with higher cumulative temperature and cumulative solar radiation for an effective grain filling period. The reduction in SPAD value ${\times}$ leaf dry weight from heading to harvest significantly correlated with final grain dry weight in a positive manner. No significant relation was found between grain filling duration and the decrease in SPAD value ${\times}$ leaf dry weight during the grain filling period. The results suggest that grain filling duration and loss of leaf activity during ripening independently contribute to environmentally induced yield improvement in temperate japonica rice.

• Korean Journal of Environmental Agriculture
• /
• v.29 no.4
• /
• pp.343-347
• /
• 2010

Heavy application of fertilizer and manure in excess from the optimum requirement for crop growth can increase phosphorus (P) accumulation and P release potential in soils. In this study, the relationship between soil test P and 0.01M $CaCl_2$ extractable P was analysed to evaluate the P release potential of agricultural soils under different land-use. The paddy, upland, plastic film house(PFH) soils were sampled from Tongyoung and Changnyeong, and Daegok areas in Gyeongnam province, respectively. With respect to the P accumulation, available P contents in upland and PFH soils were 619 and 796 mg $P_2O_5$/kg, respectively indicating that different land-use types can greatly impact soil P accumulation. As soil available P was increased in the paddy soil, the content of 0.01M $CaCl_2$ extractable P also linearly increased without change point. Comparatively, P threshold were detected at 520 mg $P_2O_5$/kg in both upland and PFH soils, indicating that P release potential were higher in these land-use systems. For reducing P release from agricultural soils, management of optimum P content is needed in soils possessing high P release potential. Further, the change point value, if it is to be used as an environmental indicator, requires more detailed investigation to cover a wide range of soil characteristics.

• Korean Journal of Environmental Biology
• /
• v.34 no.3
• /
• pp.169-176
• /
• 2016

Although chemical fertilizers have a quick effect and broad applicability to agricultural fields, they have caused many problems like increasing soil acidity or decreasing soil organic matters. Environmental-friendly agriculture has been attempted in various ways such as organic agriculture, natural farming, low input and sustainable agriculture. The common interest of all environmental-friendly systems is to decrease burden to agricultural environment by low input of agricultural labor and materials. This study was conducted to estimate overwintering capacity and genetic distance among Chinese Milk Vetch (Astragalus sinicus, CMV) collections based on morphological characteristics and AFLP (Amplified fragment length polymorphism) analysis. Furthermore, the effect of CMV as green manure was observed in mix-cultured paddy fields with rice, sesame and sweet-potato. An another objective of this study was also to compare the pattern of weed occurrence in paddy fields with or without CMV and different rice transplanting times. The CMV collected from Paju district in central region of Korea was successively occurring through self-reseeding without artificial management. However, there was no noticeable difference in growth habit between Paju native CMV and introduced CMV from China which is currently used in farm fields. On the basis of multi-dimensional scaling and tree analyses, there are no significant difference of agricultural growth characteristics among Paju and chinese collections only excepting leaf angle and root length. The flowering time of Gurye collection was fast for 1 week as compared to other collections. AFLP that was commonly used for plant classfication, was applied to exam the genetic variation of CMV collections. Total 579 PCR products and 336 polymorphic fragments were generated using 8 primer pairs.

• The Journal of Engineering Geology
• /
• v.15 no.4 s.42
• /
• pp.381-390
• /
• 2005

S City depends on the T River as source water for water supply. Arsenic and boron from the hot-spring waste-water discharged from the hot-spring spa resort and emerging from the fractures of bedrock of the river have been prevalent contaminant of the T River water. This research was conducted to propose the simple and quick surrogate parameter for water quality management easily. And through making hexa-diagram of principal ions in the water samples, existing state of the water and influence of the human activity or geological origin can be figured out. As a results of characteristics of the T River water quality using principal component analysis, the contributory percentages of the 1st, 2nd and 3rd principal components were $40.80\%,\;21.40\%\;and\;11.31\%$, respectively. Therefore it was clarified that the quality of the T River water could be explained by these three principal components. Concentration of the chloride ion, which is one of the characteristics of the hot-spring water, was well correlated to both arsenic and boron concentrations. Hence concentrations of the arsenic and boron in the raw water of the water reatment plant can be predicted by the measurement of concentration of the chloride ion.

• Horticultural Science & Technology
• /
• v.35 no.1
• /
• pp.98-107
• /
• 2017

A DNA profile database was constructed to investigate the genetic relatedness of 72 germplasm samples of Pyrus and related cultivars using microsatellite markers. Three P. pyrifolia, four P. commus, and one P. betulifolia cultivars with different morphological traits were screened using 387 pairs of microsatellite primers. A core set of 11 primer pairs was selected to obtain 133 polymorphic amplified fragments meeting three criteria: high polymorphism information contents (PIC), high repeatability, and distinct allele patterns. The number of alleles per locus ranged between 4 and 22. Average PIC was 0.743 (range: 0.557 - 0.879). Cluster analysis using the unweighted pair - group method with arithmetical average (UPGMA) separated the 72 pear cultivars and germplasm samples into four major groups: Chinese, European pears, and a cluster of 55 Asian pears that could be reclassify into two subcluster, I - $1^{st}$ and II - $2^{nd}$, according to pedigree information. Almost all of the cultivars were discriminated by 11 microsatellite marker genotypes. The microsatellite DNA profile database may be utilized as tool to verify distinctness, uniformity, and stability between candidate cultivar, and to verify in the distinctness of existing cultivars.

• Korean Journal of Ecology and Environment
• /
• v.33 no.1 s.89
• /
• pp.31-37
• /
• 2000

For the purpose of surveying the physicochemical composition of sediment collected from Kwangyang Bay, the percentage of water loss, COD, $H_2S$, grain size and 10 heavy metals were studied at 17 sites. During the surveying period, the changes of the percentage of water loss were appeared $35.5\;{\sim}\;53.8%$. COD and $H_2S$ were showed $3.8\l{\sim}\;12.9\;mg/g$, and $0.1\;{\sim}11.4\;{\mu}g/g$, respectively, In composition of grain size on the sediment, percentages of grain sizes under $74\;{\mu}m$ were varied from 40.5% to 86.7% and above $74\;{\mu}m$ were varied from 11.5% to 43.0%. From the spatial distribution of heavy metal using contour map, we can suppose some heavy metal discharges which affect sediment of Kwangyang Bay, It was estimated that Shinpung creek, Ssang-bong creek, and draining area of sewange treatment plant were the main discharge among the heavy metal output sources. By comparison between present study and heavy metal guideline of nonpolluted sea sediment that is provided by EPA, US, it was showed that the contents of Pb and Hg were acceptable but contents of Mn, Zn, Cu, Fe, As, and Cr were higher than those of EPA guideline.

• Korean Journal of Ecology and Environment
• /
• v.50 no.1
• /
• pp.116-125
• /
• 2017

Alpine plants with a scarcity of pollinators in harsh environments have been believed to undergo selfing for reproductive assurance; however, contradictory evidence is also available. Snowmelt regimes in alpine areas function to change life history characteristics of alpine plants such as flowering time and duration; yet the effects of snowmelt regimes have never been tested in alpine plants in Korea. This study was conducted to investigate the dichogamy, mating systems, and flowering characteristics of Megaleranthis saniculifolia populations [early and late snowmelt plots (ESP and LSP, respectively)] in a subalpine area of Sobaeksan Mountain in Korea. M. saniculifolia exhibited incomplete protogyny in that despite early maturation of pistils, maturation times of pistils and stamens within flowers were partly overlapped. Control and hand-outcrossing treatments produced significantly higher number of follicles and seeds per flower than autonomous and hand-selfing treatments. Based on the aggregate fruit set, the auto-fertility index (AI) and self-compatibility index (SI) were 0.33 and 0.50, respectively. Snowmelt occurred 10 days earlier in ESP than in LSP, thereby ESP and LSP showed distinct differences with regard to flower longevity and season, but showing no difference in peak flowering dates. We concluded that M. saniculifolia is an incomplete protogynous and largely outcrossing plant requiring pollinator service. Temporal variation in snowmelt time and subsequent changes in flowering characteristics under climate change may further threaten the population persistence of M. saniculifolia which has already been designated as endangered species in Korea.

• Korean Journal of Ecology and Environment
• /
• v.50 no.3
• /
• pp.314-324
• /
• 2017

In order to consider application and evaluation of value and class of domestic wetland, we investigated 146 wetlands located Gyeongsangnam-do using Rapid Assessment Method (RAM). We utilized Self-Organizing-Map (SOM) to analysis relationship between evaluation index and land coverage ratio surrounding wetland. Among total 8 evaluation index, 'Fish and herptile habitat' and 'Aesthetic value' were higher, most of the wetlands evaluated as 2, 3 grade. Result of SOM analysis, 'vegetation diversity and wild animals habitat' is negatively related to the 'Fish and herptile habitat', because fishs were not prefer habitat excessively occupied by plant. However, high vegetation diversity can be support high score of 'Aesthetic' in wetland. Also, 'Erosion control' and 'Flood storage and control' were closely related, wetlands with high score of 'Erosion control' have high score of 'Flood storage and control'. When applied RAM in domestic wetland, six out of 6 evaluation index induced biased results, the index of RAM need a little change as some new or modify evaluation index. Therefore, we consider to need adjustable, subdivide, and actualization of some evaluation index for application of RAM in domestic wetlands. Consequently, wetland assessment and class using RAM can be utilized as important indicate for conservation and management of wetland, and contributed greatly to maintain biodiversity include to endangered species by preserving remaining wetland.