• Clean Technology
• /
• v.7 no.4
• /
• pp.251-263
• /
• 2001

This study was conducted to provide a basic information for recovery plan of Seung-Gi Stream which is a major stream of Incheon metropolitan area. Source and characteristics of pollutants were analyzed and studied. Samples were taken 10 rounds in 5 sections in Seung-Gi stream. Annual pollutants loads and sectional characteristics of pollutants loads were investigated regarding flow rate, pH, DO, SS, $BOD_5$, $COD_{Cr}$, T-P, TKN and concentrations of Zn, Cd, Cu, Cr atoms which enter into Seung-Gi stream during rainy and dry season respectively. As one came close to the Nam-Dong Industrial Complex, sectional discharge loads were heavy and water quality was failed to meet the standard by "Environmental Standard of River Quality". As a result, heavy load of pollutants in Seung-Gi stream was considered to influence negatively the sea water quality of Incheon. Solution plans to solve problems are as follows. First, circulation of treated water at Seung-Gi WWTP(Wastewater Treatment Plant) and retreated water by URC(ultra rapid coagulation) process treat with that. Second, sewage and wastewater is gathered, make it disposed. After then, we circulate treated water. If solution plans be applied, we can predict water quality. Then we could grope for how make to recovery role of Seung-Gi stream as stream.

• Journal of Energy Engineering
• /
• v.20 no.1
• /
• pp.36-43
• /
• 2011

Plant biomass has been proposed as an alternative source of petroleum-based chemical compounds. Especially, aromatic chemical compounds can be obtained from lignin by depolymerization processes because the lignin consist of complex aromatic materials. In this study, kraft lignin, the largest emitted substance among several kinds of lignin in Korea, was used as a starting material and was characterized by solid-state $^{13}C$-Muclear Magnetic Resonance($^{13}C$-NMR), Fourier Transform Infrared Spectroscopy(FT-IR), Elemental Analysis(EA). The depolymerization of kraft lignin was studied at water-phenol mixture solvent in near critical region and the experiments were conducted using a batch type reactor. The effects of water-to-phenol ratio and reaction temperature($300-400^{\circ}C$) were investigated to determine the optimum operating conditions. Additionally, the effects of formic acid as a hydrogen-donor solvent instead of $H_2$ gas were examined. The chemical species and quantities in the liquid products were analyzed using gas chromatography-mass spectroscopy(GC-MS), and solid residues(char) were analyzed using FT-IR. GC-MS analysis confirmed that the aromatic chemicals such as anisole, o-cresol(2-methylphenol), p-cresol(4-methylphenol), 2-ethylphenol, 4-ethylphenol, dibenzofuran, 3-methyl cabazole and xanthene were produced when phenol was added in the water as a co-solvent.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.46 no.1
• /
• pp.49-60
• /
• 2018

The role of the botanical garden in securing biodiversity, responding to climate change, and sustainable development in modern cities is becoming more important. Private botanical gardens that lead the domestic botanical culture are declining due to complex reasons such as an increase of tourist destinations, lack of policy support, lack of introduction of advanced management strategies, and similar leisure activities to national and public botanical gardens. The Private Botanical Garden not only has a large number of plant species with high conservation value, but also provides various public utilities as a cultural and educational space and government efforts are needed to activate the operation of this amenity. The purpose of this study is to evaluate the value of public functions provided by private botanical gardens using the Contingent Valuation Method (CVM). In this way, the government aims to provide a basis for policy and institutional support for private botanical gardens. The main results are as follows. First, public utility functions provided by private botanical gardens were recognized as 'preservation' (23.4%), 'recreation and tourism' (17.5%) and 'research' (16.6%) in order of analytic hierarchy process (AHP). Second, 'heritage value' (33.0%) and 'existence value' (32.5%) were recognized as significant among the values provided by private botanical gardens. Third, the willingness to pay (WTP) to preserve the public functions of the private botanical garden was 12,234 won. Based on this, the economic value of all private botanical gardens in the whole country was estimated, resulting in about 233.8 billion won. There is a need to revise laws and regulations related to financial support for the revitalization and quality improvement of private botanical gardens. It is also necessary to establish a cooperative operating system between national, public and private botanical gardens.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.29 no.6
• /
• pp.335-349
• /
• 2017

Submerged breakwaters installed under the water surface are a representative coastal structure to prevent coastal erosion, and various types of submerged breakwaters have been proposed and discussed so far. Generally, submerged breakwaters make the complex wave fields due to abrupt change in water depth at the crown of the breakwater. In this study, wave heights and mean water level formed around a breakwater are examined numerically for three-dimensional permeable submerged breakwaters. OLAFOAM, CFD open source code, is applied in the numerical analysis, and the comparisons are made with available experimental results on the permeable upright wall and the impermeable submerged breakwater to verify its applicability to the three-dimensional numerical analysis. Based on the applicability of OLAFOAM numerical code, the wave height and mean water level distribution formed around the permeable submerged breakwaters are investigated under the formation condition of salient. The numerical results show that as the gap width between breakwaters decreases, the wave height in the center of the gap increases, while it decreases behind the gap, and the installing position of the breakwater from the shoreline has little influence on the change of the wave height. Furthermore, it is found that the decrease of the mean water level near the gap between breakwaters increases with decreasing of the gap width.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.11 no.1
• /
• pp.27-38
• /
• 2009

The multi-level profile system is designed to measure the vertical profile of $H_2O$ and $CO_2$ concentrations in the surface layer to estimate the storage effects within the plant canopy. It is suitable for long-term experiments and can be used also in advection studies for estimating the spatial variability and vertical gradients in concentration. It enables the user to calculate vertical fluxes of water vapor, $CO_2$ and other trace gases using the surface layer similarity theory and to infer their sources or sinks. The profile system described in this report includes the following components: sampling system, calibration and flow control system, closed path infrared gas analyzer(IRGA), vacuum pump and a datalogger. The sampling system draws air from 8 inlets into the IRGA in a sequence, so that for 80 seconds air from all levels is measured. The calibration system, controlled by the datalogger, compensates for any deviations in the calibration of the IRGA by using gas sources with known concentrations. The datalogger switches the corresponding valves, measures the linearized voltages from the IRGA, calculates the concentrations for each monitoring level, performs statistical analysis and stores the final data. All critical components are mounted in an environmental enclosure and can operate with little maintenance over long periods of time. This report, as a practical manual, is designed to provide helpful information for those who are interested in using profile system to measure evapotranspiration and net ecosystem exchanges in complex terrain.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.65 no.4
• /
• pp.386-398
• /
• 2020

Wheat is one of the world's top three crops and is an important staple crop, accounting for 20% of the nutrient calories consumed by the world's population. However, due to its complex heterogeneous hexaploid chromosomes and vast genome of approximately 16 Gb, compared to those of other crops, molecular biology and biotechnology studies on wheat are lacking. In recent years, wheat genome analysis has been performed using the latest next-generation sequencing technology so that useful genes can be easily obtained, and wheat biotechnology research is accelerating in various fields. In this review, wheat transformation, an indispensable technique for developing new functional biotech wheat by revealing the function of wheat genes, is described in detail. In addition, the latest research results for overcoming plant diseases, abiotic stresses, and wheat-related diseases that are difficult to solve by classical breeding through wheat transformation and biotechnology are described.

• Korean Journal of Soil Science and Fertilizer
• /
• v.50 no.2
• /
• pp.115-126
• /
• 2017

There is an increasing concern over arsenic (As) contamination in rice. This study was conducted to develope a prediction model for As uptake by rice based on the physico-chemical properties of soil. Soil and brown rice samples were collected from 46 sites in paddy fields near three different areas of closed mines and industrial complexes. Total As concentration, soil pH, Al oxide, available phosphorus (avail-P), organic matter (OM) content, and clay content in the soil samples were determined. Also, 1.0 N HCl, 1.0 M $NH_4NO_3$, 0.01 M $Ca(NO_3)_2$, and Mehlich 3 extractable-As in the soils were measured as phytoavailable As concentration in soil. Total As concentration in brown rice samples was also determined. Relationships among As concentrations in brown rice, total As concentrations in soils, and selected soil properties were as follows: As concentration in brown rice was negatively correlated with soil pH value, where as it was positively correlated with Al oxide concentration, avail-P concentration, and OM content in soil. In addition, the concentration of As in brown rice was statistically correlated only with 1.0 N HCl-extractable As in soil. Also, using multiple stepwise regression analysis, a modelling equation was created to predict As concentration in brown rice as affected by selected soil properties including soil As concentration. Prediction of As uptake by rice was delineated by the model [As in brown rice = 0.352 + $0.00109^*$ HCl extractable As in soil + $0.00002^*$ Al oxide + $0.0097^*$ OM + $0.00061^*$ avail-P - $0.0332^*$ soil pH] ($R=0.714^{***}$). The concentrations of As in brown rice estimated by the modelling equation were statistically acceptable because normalized mean error (NME) and normalized root mean square error (NRMSE) values were -0.055 and 0.2229, respectively, when compared with measured As concentration in the plant.

• Korean journal of applied entomology
• /
• v.50 no.2
• /
• pp.97-105
• /
• 2011

Understanding the metapopulation structure and movement of a species are required for conserving the species. In this paper, migration patterns and connectivity of patches of a threatened butterfly, Parnassius bremeri Bremer, were postulated using the mark-release-recapture (MRR) technique in a habitat located in the mid-southern region of the Korean peninsula. A total of 194 individuals were captured (137 males and 57 females) and, of them, 93 individuals (73 males and 20 females) were recaptured during the MRR experiment. The migration analysis showed 23-150% immigration and 28-53% emigration. There were high correlations between the migrating individuals and the distance between patches, but there was no correlation between migrating individuals and patch size or between migrating individuals and the number of host plants. Consequently, the migration of butterflies occurred frequently between closer patches, while patch size and quantity of the food plant had minor effects on migration behavior. Additionally, males migrated more frequently than females. Analysis of the migration patterns of P. bremeri showed that the central patch played an important role on linking patch groups and more frequent migrations were monitored between nearby patches than between the remote patches. This study suggested that active migrations take place between the neighboring multiple patches and these are accelerated if there is a stepping-stone patch between them.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.12 no.1
• /
• pp.25-31
• /
• 2017

The objective of this study is to find the failure factors of venture companies. We analyze 210 troubled venture companies, all of which have been under guarantee from the Korea Technology Finance Corporation over the last three years. Methods of analysis for failure factors are as follows. First, we categorize the failure factors into the four different types based on growth and profitability indicators in the financial statements of targeted venture companies. Then we analyzed the failure factors of the subject companies based on the troubled guarantee reports made by the Korea Technology Finance Corporation. If a venture company under its guarantee program falls into insolvency, the Korea Technology Finance Corporation make the troubled guarantee report to find out the failure factors and evaluate the recovery potentials. We identify 374 failure factors of venture companies through the analysis. The most prominent among them are deteriorating of business environments (79 factors) and decreasing or withdrawing orders from major suppliers (54 factors) due to bankruptcies or change in business plans. They are followed by slowing collection of accounts receivable (31 factors), dropping or frozen product price (24 factors) due to intensifying competition and escalating pressures from major suppliers, rising raw material costs both at home and abroad (21 factors). In addition, the nuclear power plant disaster in Japan, shut-down of the Kaesong Industrial Complex and subsequent lawsuits, delay in technology development projects, high cost-low efficiency management structure, etc., are also revealed as new factors causing trouble for venture companies.

• Korean Journal of Soil Science and Fertilizer
• /
• v.47 no.1
• /
• pp.41-47
• /
• 2014

Agricultural soils surrounding mine areas in South Korea are often contaminated with multiple metals such as Cd, Pb and Zn. It poses potential risks to plants, soil organisms, groundwater, and eventually human health. The aim of this study was to examine the changes in phytoavailability of Cd, Cu, Pb and Zn after application with calcined eggshell (CES; 0, 1, 3, and 5% W/W) in an agricultural soil contaminated by mine tailings. The contents of Cd, Cu, Pb and Zn in soils were 8.79, 65.4, 1602, and $692mgkg^{-1}$ (aqua regia dissolution), respectively. The experiments were conducted with lettuce (Lactuca sativa L. var. longifolia) grown under greenhouse conditions during a 30-d period. $NH_4NO_3$ solution was used to examine the mobile fraction of these metals in soil. The application of CES dramatically increased soil pH and inorganic carbon content in soil due to CaO and $CaCO_3$ of CES. The increased soil pH decreased the mobile fraction of Cd, Pb, Zn: from 3.49 to < $0.01mgkg^{-1}$ for Cd, from 79.4 to $1.75mgkg^{-1}$ for Pb, and from 29.6 to $1.13mgkg^{-1}$ for Zn with increasing treatment of CES from 0 to 5%. In contrast, the mobile fraction of Cu was increased from 0.05 to $3.08mgkg^{-1}$, probably due to the formation of soluble $CuCO_3{^0}$ and Cu-organic complex. This changes in the mobile fraction resulted in a diminished uptake of Cd, Pb and Zn by lettuce and an increased uptake of Cu: from 4.19 to < $0.001mgkg^{-1}$ dry weight (DW) for Cd, from 0.78 to < $0.001mgkg^{-1}$ DW for Pb, and from 133 to $50.0mgkg^{-1}$ DW for Zn and conversely, from 3.79 up to $8.21kg^{-1}$ DW for Cu. The increased contents of Cu in lettuce shoots did not exceed the toxic level of $>25mgkg^{-1}$ DW. The mobile contents of these metals in soils showed a strong relationship with their contents in plant roots and shoots. These results showed that CES effectively reduced the phytoavailability of Cd, Pb, and Zn to lettuce but elevated that of Cu in consequence of the changed binding forms of Cd, Cu, Pb, and Zn in soils. Based on these conclusions, CES can be used as an effective immobilization agent for Cd, Pb and Zn in contaminated soils. However, the CES should be applied in restricted doses due to too high increased pH in soils.