• Journal of the Korea Institute of Building Construction
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• v.10 no.3
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• pp.129-136
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• 2010

This study is an evaluation of the water-tightness properties of rain-block systems in the sliding-roof joint of large-span membrane structures. In this study, we suggested a method of evaluating the water-tightness performance of the joint part of a sliding door in the roof of a large-span membrane structure (for a pilot project), in an environment of rain and wind. The shape of the rainwater blocking systems of the joint part in a sliding door verifies the defects and the effects of water leakage prevention when there is precipitation with wind conditions. To secure the water-tightness of large span membrane structures, it is necessary to have a guideline on the evaluation of the design for rain-block system of the joint part, and the quality of the membrane material, both of a retractable roof and a closed roof.

• Fisheries and Aquatic Sciences
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• v.8 no.4
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• pp.220-227
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• 2005

The estrogenic phenolic compounds, nonylphenol (NP), octylphenol(OP), bisphenol A (BPA) and nonylphenol mono- and diethoxylate ($NP_{1-2}EO$) were analyzed in 24 surface water samples from six rivers flowing into Masan Bay. All of the phenolic compounds were detected in all six rivers in high concentrations. The most abundant compound was $NP_{1-2}EO$ (86.0%), followed by NP ($10.1 \%$), BPA ($3.6\%$) and OP ($0.3\%$). The levels of phenolic compounds were 1.42-22.70 ${\mu}g$/L for $NP_{1-2}EO$, 0.15-1.68 ${\mu}g$/L for NP, 0.024-0.610 ${\mu}g$/L for BPA and 0.003-0.067 ${\mu}g$/L for OP. Especially, high concentrations were recorded in the rivers that pass through industrial complexes. The concentrations of phenolic compounds observed in these river waters were 1-2 orders of magnitude lower than the reported acute toxicity levels (hundreds of micrograms per liter). However, they were only slightly lower than the chronic toxicity levels. Most of the water samples also exceeded the Canadian nonylphenolic compounds water quality guideline, 1 ${\mu}g$/L, for the protection of aquatic life and the maximum permissible concentrations (MPC), 0.33 ${\mu}g$/L for NP and 0.12 ${\mu}g$/L for $NP_{1-2}EO$.

• Journal of the Korea Institute of Building Construction
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• v.22 no.6
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• pp.631-640
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• 2022

Recently, construction accidents have occurred due to illegal water addition and insufficient quality control at domestic construction sites. In this study, the void content test method proposed in ASTM C 642 was used to provide a reference guideline for evaluation on the quality control status of cast-in-place structural concrete. For this purpose, simulated structural concrete for coring purpose was prepared in addition to the concrete cylindrical specimens with the same formulation, and the changes in compressive strength, elastic modulus, and void content related to coring were evaluated. According to experimental results, the compressive strength and modulus of elasticity were reduced by coring, which was associated with the generation of microcracks during coring. With respect to void content, the difference in void content between the cylindrical specimen and the cored specimen was up to 1.69%. If this value is used as a correction factor, it is possible to estimate the real void content of the cast-in-place structural concrete. By comparing this with the void content obtained from cylindrical concrete specimens, it is possible to evaluate the quality control status and amount of illegal water addition on the structural concrete.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.714-722
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• 2017

The TPLMs is a system to manage the total amount of pollutants discharged from the watershed in order to achieve the target water quality of the river. In this process, the pollutant load can be classified into generation, discharge and delivery load. When using equation 2, the discharge coefficient should be 1. In case of using equation 3, it is considered that the discharge coefficient defined in the Technical Guideline should be applied. The delivery load is calculated as the product of the discharge load and the delivery ratio, and the delivery ratio is defined as the rate at which the pollutant discharged from the watershed reaches a specific point in the stream. In this study, the delivery ratio estimation method proposed by Hwang (2016) was applied to the Yonggang watershed in the Nakdong river. And the input data of QUALKO2 model was generated by using the estimated delivery ratio (equation 3) and the validation study was conducted by comparing with DRave (equation 2). As a result of the study, it is possible to use both the equation 2 and the equation 3, but it is necessary to change the methodology according to the application of the discharge coefficient.

• Journal of Environmental Impact Assessment
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• v.31 no.3
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• pp.141-160
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• 2022

The harbor construction projects can lead to various marine environmental problems including habitat degradation and loss, marine water pollution, change of flow patterns, erosion, scour, sedimentation, and so on. The EIA is a measure to prevent various environmental problems in advance from examining and minimizing the environmental impacts before the proposed developments are implemented. In addition, institutions reviewing EIA reports have made efforts to conduct scientific and standardized EIA by applying EIA guidelines for each project. This study aims to create a EIA guideline focusing on the harbor construction projects. Based on the review comments of the harbor construction EIA reports for the past 13 years (2009-2021) and the EIA guidelines of different types of projects, we identified the marine environmental problems and provided the appropriate guideline. This guideline summarizes and presents the contents which must be reviewed in the baseline condition survey, impact assessment, mitigation, and post-environmental impact investigation in the fields of marine fauna and flora, marine physics, and marine water and sediment quality. In the case of a baseline condition survey of marine fauna and flora, a method for selecting survey points considering the characteristics of sea area and project was presented. When estimating the impact of marine fauna and flora, we presented methods for predicting the impact on them due to the spread of suspended sediments and the damage to benthic habitats due to dredging and reclamation. In consideration of the characteristics of the sea area, we divided the survey items of the marine physics into essential items and supplementary items. In predicting the impact of marine physics, various methods for major issues such as seawater circulation, suspended sediment and bottom sediment transport, water temperature and salinity diffusion, seawater exchange, wave transformation, harbor tranquility, and shoreline change were presented. The research results will contribute to protect the marine environment by inducing more systematic and scientific surveys, impact assessments, and mitigation in the EIA process.

• Journal of Applied Biological Chemistry
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• v.65 no.3
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• pp.195-202
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• 2022

Soybean (Glycine max L.) leaves have been researched as functional food stuff actively, but there is no validation method to control quality of soybean leaves (SL). In this study, we annotated seven kaempferol derivatives to confirm camelliaside A as index metabolite in SL using UHPLC-ESI-TOF-MS. HPLC-UVD validation method of camelliaside A in hot-water extract of SL was established according to validation guideline of functional foods from the Ministry of Food and Safety of Korea. The HPLC-UVD method was validated with reliable parameters for examining specificity, accuracy, precision, limit of detection and quantification and linearity. The established method gave the suitable ranges to qunatitate camelliaside A from the hot-water extract of soybean leaves.

• Journal of the Korea Concrete Institute
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• v.20 no.3
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• pp.375-381
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• 2008

Various problems such as durability degradation may happen when extra water is added to concrete. Because of these reasons, the change of water content is managed by using rapid evaluation method of unit water content such as electric capacity method, heat drying method making use of micro wave, unit capacity mass method among various methods. Especially, in Japan, guidance for the change of water content ($\pm$ 10, 15, 20 kg/$m^3$ etc.) were regulated and used. However, it is the real situation that the guidance which were regulated in South Korea evaluate suitability only considering production and measurement error under the circumstances which are not considering the degree of durability degradation. Therefore, this study tries to investigate the influence of addition of extra water in the concrete on the durability degradation of concrete when it was added by artificial manipulation or by management error. From the test results, a guideline of the contents of extra water for the quality control is suggested with the consideration of the degree of durability degradation and the probable error resulted from the addition of extra water. The contents of extra water for tests are set as 0, 15, 25, 35 kg/$m^3$. To examine the durability degradation of concrete, freezing and thawing, carbonation, chloride penetration and compressive strength are tested.

• Hwankyungkyoyuk
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• v.10 no.2
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• pp.175-190
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• 1997

The objective of this study is to increase bio-diversity by developing more efficient methods to created habitats and applying them in introducing prototypes of forest, grassland, and marsh which are found in natural ecosystem, to urban environment. In this context, in creating man-made marsh in Seoul Engineering High School, firstly, philosophical framework to create man-made marsh to restore urban nature and conceptual system to create a region considering life and ecosystem were established. Secondly, by applying the philosophical framework and the conceptual system, water quality section, plantation section, and techniques to create habitats to increase bio-diversity were introduced. Lastly, when the creation is completed, maintenance of the marsh will continue with participation and education of students and residents. This study presents how natural environment can be restored and created in urban areas. This may be viewed as modest beginning. I expect this study proves to be effective in increasing bio-diversity, fulfill its role as an experiment station for restoration and creation of natural environment and natural educational center for students and community as well as habitats for wild life, and open a new chapter in developing a society seeking co-existence of humankind and life. Therefore, when technological guideline on restoration and creation of man-made marsh in urban area is developed based on the outcome of this study, expansion of the project to nationwide including metropolitan cities like Seoul is recommended.

• Journal of Environmental Science International
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• v.14 no.7
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• pp.683-689
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• 2005

The consecutive combination process of a biological process as the pre-treatment and a chemical process as the post-treatment is applied for the dyeing wastewater. The poor efficiency of biological treatment using pure oxygen makes the chemical treatment cost high. It is necessary to improve the efficiency of biological treatment in order to reduce the cost of chemical treatment. The purpose of this paper is to find the minimum dose of chemical reagent to fit the Discharged Water Quality Standards for the different biological treatment effluents. Results revealed that the minimum dosage of Fenton's reagent lead to save the cost of chemical treatment based on the guideline dose in the treatment plant. The possible maximum saving reagents was up to $70\%$ for the effluent of the pilot plant packed with the carrier imbedded microorganisms which were selected from the present treatment plant.

• International Journal of Advanced Culture Technology
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• v.7 no.2
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• pp.125-136
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• 2019

This study focuses(selected) on garden facilities of designer gardens created at the 1st and 2nd Seoul Garden Shows and examined installed facilities at each designer garden by categorization according to type, material and functions. The study observed problems occurring from maintenance of garden facilities as time passes by and collected basic data to develop maintenance guideline aiming to make contribution to further spreading and promotion of high quality garden culture. This study examined all gardens created at 1st and 2nd Seoul Garden shows in 2015 and 2016. There were 18 gardens built in 2015 and 16 in 2015.The study looked at responsible entities for maintenance of facilities and examined maintenance system for managing these gardens. Garden facilities of the study were categorized into paving, facility for rest, playground, water facility, environmental sculpture and planting media facility according to categorization by landscape design standards and construction guidelines. Target gardens of this study are maintained mostly by citizen gardeners who are passionately carrying out maintenance work while communicating with designers. However, these citizen gardeners lack technical knowledge to manage various facilities. Also, maintenance manuals submitted by garden designers do not offer sufficient details on facility maintenance which calls for professional maintenance and clear instructions on facilities from early phase of design.