• KSBB Journal
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• v.30 no.6
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• pp.283-290
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• 2015

In this study was selected the cellulolytic microorganism and investigated optimum condition of cellulase production for the cellulosic bioethanol production. A bacterial strain Paenibacillus jamilae BRC15-1, was isolated from soil of domestic reclaimed land. For optimizing cellulase production from the selected strain, various culture parameters were investigated such as culture medium, pH (pH 4~10), temperature ($25{\sim}50^{\circ}C$) and culture time (2~72 h). As a result, P. jamilae BRC15-1 efficiently produced cellulase from cellulosic biomass under following conditions: 24 h of culture time (pH 7, $40^{\circ}C$) in manufactured media of CMC (carboxymethyl cellulose) with peptone. Optimum saccharifying condition of crude enzyme produced from P. jamilae BRC15-1 was identified on pH 6 and $40^{\circ}C$ of reaction temperature, respectively. This crude enzyme from P. jamilae BRC15-1 was used for saccharification of pretreated sweet sorghum (Sorghum bicolor var. dulciusculum Ohwi) bagasse under the optimal condition. Finally, pretreated sweet sorghum bagasse including 0.1 g of glucan was saccharified by crude enzyme of P. jamilae BRC15-1 into 2.75 mg glucose, 0.79 mg xylose and 1.12 mg arabinose.

• Korean Journal of Ecology and Environment
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• v.52 no.4
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• pp.366-377
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• 2019

Paddy wetlands are a critical habitat for a variety of wild animals, and their rapid development and environmental changes pose a threat to the conservation of agrobiodiversity. The objectives of this study were to evaluate the habitat characteristics of anuran inhabiting paddy wetlands and identify major environmental variables affecting their distributions. The study was conducted in the Daeho reclaimed area in Dangjin, from March to October 2018. In this study, we found three anuran species (Pelophylax nigromaculatus, Hyla japonica and Pelophylax chosenicus). The environmental factors affecting the three species were identified as air temperature, humidity, water-depth, and micro-habitats. H. japonica were affected by water temperature, and P. chosenicus were affected by rice height and types of farming practices. All the three species richness was correlated with air temperature, humidity, and water-depth positively, and the three species used rice transplanted paddy fields the most. It was also found that paddy is the most preferred of the micro-habitats during the breeding season, so the survey area is considered to be used as the major breeding sites for the three species. P. chosenicus were more observed on environmental-friendly paddy fields than conventional paddy fields, which appears to be differences in their surroundings environment caused by predators and weeding. It will be needed to identify their relationship with predators, their preferred food resources and the richness and diversity of wild vegetation around paddy wetlands.

• Journal of Plant Biotechnology
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• v.42 no.2
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• pp.129-134
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• 2015

In order to compare salt tolerance among potato cultivars (Solanum tuberosum L.), in vitro plants of each cultivar were cultured on the Murashige and Skoog's medium containing different levels of NaCl (0, 75, 150, and 225 mM). The suitable level of NaCl for a comparison of the shoot and root growth between potato cultivars was 75mM. Shoot length and weight were better in 'Dejima', 'Superior', 'Jayoung', and 'Haryeong' than in other cultivars such as 'Goun' and 'Atlantic'. Normal root growth was observed in 'Seohong', 'Superior', and 'Haryeong', while 'Goun', 'Atlantic', 'Dejima', 'Jowon', and 'Chuback' showed no root. Proline contents in all the cultivars increased as affected by NaCl levels, then the increase amount was fewer in the cultivars showed a better growth in both shoot and root than in others showed a poor growth. As a result of this study, 'Superior' and 'Haryeong' were determined as salt tolerant cultivars and therefore using these cultivars it would be possible to potato production at salt arable land such as reclaimed tidal.

• The Journal of Engineering Geology
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• v.21 no.3
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• pp.213-219
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• 2011

Transient/time-domain electromagnetic (TEM) soundings were carried out on reclaimed land, since the TEM sounding has good resolution of a conductive and thin overburden. The reclamation material is marine clay dredged from the seafloor, which is currently undergoing consolidation in the upper part of the dredged layer. The conductivity of the marine-origin clay is generally more than 0.3 S/m. The aim of the TEM sounding was to determine the depths of weathered and soft rocks overlain by thick and conductive overburden. The TEM responses were measured at delay times of 0.050-20.575 ms with a $30{\times}30$ m coincident loop array. Data from the TEM inversion and core logging indicate that the resistivities of the conductive overburden are less than 2 ${\Omega}$-m, while those of the weathered and soft rocks are 10-20 and 70 ${\Omega}$-m, respectively. The depth to weathered rock is 26-58 m and the depth to soft rock is 46-75 m.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.483-488
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• 1993

This study was conducted to obtain the basic information for easily judgement to level of salinity stress of the reclaimed land. Rice varieties used were Nakdongbyeo and Chilsungbyeo. In seedling stage, 13 day-old seedlings were subjected to salt solution (0, 30, 60, 90mM) for 8 days. In reproductive stage, 30 day-old seedlings were transplanted 3 hills(3 seedlings /hill) per plastic pot (diameter 28${\times}$depth 30cm). Salinity stress was given by immersing pot in the salt solution(sea water) with 4 concentrations(0, 30, 60, 90mM)for 8 days at booting stage. The stomatal resistance was increased with salinity concentrations. Salinity stress appeared to be more sensitive in seedling stage than in reproductive stage in each concentrations. The photosynthesis was decreased in salinity treatment. Salt-treated periods influenced unfavorably stomatal resistance in each stages. The leaf chlorophyll content was remarkably decreased by increasing salt concentrations. The absorption of Na+ and Cl￣ were increased as salt concentration in the culturing medium became higher, but there was no appearent difference in the absorption of K+, Mg++, and Ca++. The plant height and root length were decreased in salinity treatment. The inhibitory effect of salinity stress on root growth was more severe than in shoot growth. The stomatal resistance could have been used as bio-information.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.4
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• pp.290-298
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• 2013

A Saemangeum Development Project, which is a national project in South Korea, has started with the objective of developing the reclaimed area mainly agricultural land use since the mid'80s. To develop a model of the global eco-reclamation, constructions of the eco-friendly counter facilities such as sluice gates and inner dikes, as well as environmental preservation measures for an estuary reservoir, have been carried out. However, reasonable measures of the water quality management for the Saemangeum area are required. Thus, the purpose of this study is to rigorously analyze and quantitatively evaluate the environmental problems due to the water level management associated with inner dike constructions. To achieve these objectives, the affecting factors on determination of water level management are described and a series of calibrated transient-state numerical simulations was performed to demonstrate the salinity distribution difference in the estuary before and after the construction of inner dikes. The overall salinity reduced about 2~5 psu, and the seawater intrusion was weakened by a well-regulated waterway after construction of the inner dikes compared to before construction of them.

• The Korean Journal of Pesticide Science
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• v.12 no.4
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• pp.342-350
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• 2008

This study was carried out to investigate the suitability of the pubertal assay and the enhanced TG 407 as methods for detection of endocrine-mediated effects. Thyroid function was also considered. Male and female Sprague-Dawley rats were gavaged daily with 0, 25, 50, 100 mg/kg metribuzin in corn oil during 30 days. The effects of metribuzin on thyroid gland, the genital organs and thyroid hormone were measured in male and female rats. Dose of metribuzin 50 mg/kg/day increased relative weight of testis, prostate, and seminal vesicle in male rats but relative weight of thyroid gland was not significantly different from control group. Dose of metribuzin 25 mg/kg/day decreased relative weight of thyroid gland in female rats. Another purpose of this study was to investigate the effects of endocrine-disruptors as like thyroid hormone in vitro. Luciferase activity was measured to detect reaction of test chemicals and thyroid hormone response elements in HeLaTRE cell. Dose of metribuzin from 1 to 1,000 nM increased to 106-122% of luciferase activity.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.5
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• pp.375-384
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• 2013

Most of regions within the city of Mokpo, located on the southwest coast of the Korean Peninsula, are subjected to significant subsidence because about 70% of the city is land reclaimed from the sea (Kim et al., 2005). In this study, we aimed to estimate the rate of subsidence over Mokpo by using PALSAR L-band dataset from 2006 to 2010. Time series analysis was performed as well using GPS surveying data from 2010 to 2012. Results from these two independent datasets are then compared and analyzed over the common period of time. GPS data processing provides the results of seasonal variation on the surface, that is, via repeatedly rising and falling in association with the periodic cycle. Therefore, a time series analysis was performed to calculate the rate of ground subsidence. The deformation rates calculated for the same point are 3.89cm/yr and 2.65cm/yr from the GPS data and SAR data, respectively. SAR and GPS data processing results show a very similar pattern in terms of magnitude of annual subsidence. Thus, if the two datasets are integrated together, new modeling on ground subsidence is feasible. Lastly, subsidence was detected in a landfill area in the city of Mokpo, which has been continuously occurring through 2012.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.1
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• pp.11-18
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• 2012

This study was investigated agricultural water supply system of major agricultural waterway for Gimje canal, Jeongeup canal, Dongjin river conduit of Dongjin river basin. Furthermore, this result will be used for water resources and agricultural demand in Saemangeum reclaimed arable land. Annual precipitation for 5 years in Dongjin river basin was 1,311.7mm. The average discharges in Dongjin river basin was $1,390{\times}10^6\;m^3$ and $1,516{\times}10^6\;m^3$ and $744{\times}10^6\;m^3$ for 2,007 and 2008, respectively. Also, annual average amount of water resources was 1,861${\times}10^6\;m^3$ and $2,279{\times}10^6\;m^3$ and $1,227{\times}10^6\;m^3$ for 2,007 and 2008, respectively. Dongjin river basin water system for the analysis of agricultural water in water resources, runoff, agricultural water demand and usage surveys were analyzed, resulting in the total amount of water due to precipitation of the watershed of the $12.3{\times}10^9\;m^3$ ~$22.8{\times}10^9\;m^3$ and Dongjin River basin in waters flowing discharge is $7.4{\times}10^9\;m^3$~$16.1{\times}10^9\;m^3$, agricultural water demand and usage of each of $6.8{\times}10^9\;m^3$~$6.9{\times}10^9\;m^3$ and $4.9{\times}10^9\;m^3$~$7.1{\times}10^9\;m^3$ compared to the agricultural water demand was more likely. Agricultural water supply system in Dongjin river basin is complex because of devided branches to the main canal and branch canal. In this process, accurately assessment of water usage is very difficult. Therefore, systematic management of water resources and supply of agricultural water supply system to use the terms of the complexity and diversity by considering the appropriate level of agricultural water management systems will be needed. As a result of this study, it can be used water resources assessment in quantity, rational usefulness and basic planning of water resources development for water distribution.

• Korean Journal of Weed Science
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• v.12 no.4
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• pp.335-351
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• 1992

The identification of green algae which were collected from paddy rice fields of the whole nation was conducted in 1991, and also the reproduction processes of three important green algae were investigated. The green algae identified were 46 species in 16 families including 4 species in the Volvocaceae, 4 species in the Palmellaceae, 3 species in the Ulotrichaceae, 3 species in the Oocystaceae and 6 species in the Scenedesmaceae. It was recognized that the algae which have caused a large injury to the flooded direct-seeded rice in Seosan reclaimed saline land was the genus Cladophora. The green water blooms on paddy water were induced mostly by the concentrated populations of suspended green algae such as the genera, Chlamydomonas and Stichococcus. A rapid propagation of Hydrodictyon was resulted from the asexual reproduction forming autocolony in each mother cell. The sexual and asexual reproduction processes of Oedogonium and the sexual reproduction process of Spirogyra were observed.