• Journal of Wetlands Research
• /
• v.19 no.2
• /
• pp.240-245
• /
• 2017

In this study, we developed a method to assess quantitatively the amount and the economic value of water quality regulating service of ecosystem services. Numbers of species and aquatic organisms such as fish increased because of the improved water, but it was due to complex factors such as water quality regulation services of ecosystems, installation of environmental facilities for water quality treatment, and water quality regulation. Therefore we sought ways to quantitatively estimate the value of ecosystem regulation services. In this study, we propose a method to estimate the quantitative value of water quality regulation service of ecosystem by utilizing the total amount of water pollution. In addition, the economic value evaluation method was proposed by multiplying the estimated the quantitative value of water quality regulation service of ecosystem by the unit cost per unit capacity. Finally, the ecosystem water quality regulation service was estimated by using the evaluation method for BOD and T-P in Nakdong river watershed.

• Journal of Korean Society on Water Environment
• /
• v.25 no.6
• /
• pp.855-862
• /
• 2009

This paper pointed out major problems of land use regulation policy surrounding Paldang Lake as follows: (1) inefficient management system, (2) inconsistent administrative management, (3) illogical selection of regulated area, (4) contradictory present system, and (5) controversial discharge control. Several regulation laws for the land-use surrounding Paldang Lake caused confusion of application and inefficiency of management. Amendment of regulation laws made it possible that the regulated area was developed, which resulted in the deterioration of water quality. In addition, successive regulations without scientific implementation overexpanded regulated area and focus on the discharge concentration of contaminated sources stimulated development of small size sources. To overcome these problems, we suggested reestablishment of regulated area, differentiation of regulation amendments, and flexibility in the application of regulation. It is necessary to arrange regulated area based on the efficient land use management and scientific implementation and then to mitigate land use regulation under the sustainable development. For the flexible application of regulation, it is required to amend the rule in response to the change of environmental condition and development of environmental techniques.

• Journal of Korean Society of Water and Wastewater
• /
• v.25 no.2
• /
• pp.153-160
• /
• 2011

Ozone process is currently applied in 24 water treatment plants in Korea to control micropollutants and taste & odor compounds. However, one of the chlorine resistant protozoa, cryptosporidium, is not being considered as ozone disinfection performance whereas U.S. is already regulate Cryptosporidium by ozone disinfection. two ozone plants(PH, UH WTP) operation conditions are investigated for disinfection performance comparing Korea disinfection regulation and U.S. regulation. The ozone plants are unable to get Cryptosporidium inactivation credits by Korea disinfection regulation. However, the inactivation credit for Cryptosporidum was increased when the U.S. disinfection regulation was applied. The Korea disinfection credit regulation need revision to practical aspects.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.17 no.3
• /
• pp.21-29
• /
• 2021

In this study, the current regulation of the water source energy, one of the renewable energy, was analyzed, and the improvement plan for the high efficient data center cooling system was suggested. In the improvement plan, the design and construction guidelines of the water source energy system permit to adopt the cooling and heating system with or without heat pump. In addition, it should also include the system operated in the cooling mode only all year-round. The domestic test standards to consider the water source operating conditions should be developed. Especially, it is highly recommended that the test standards to include the system with forced cooling and free cooling modes related with the enhanced data center cooling system adopting the water source energy.

• Structural Engineering and Mechanics
• /
• v.69 no.1
• /
• pp.33-42
• /
• 2019

Thermal cracks are cracks that commonly form at early ages in mass concrete. During the concrete pouring process, the elastic modulus changes continuously. This requires the time domain to be divided into several steps in order to solve for the temperature, stress, and displacement of the concrete. Numerical simulations of thermal crack propagation in concrete are more difficult at early ages. To solve this problem, this study divides crack propagation in concrete at early ages into two cases: the case in which cracks do not propagate but the elastic modulus of the concrete changes and the case in which cracks propagate at a certain time. This paper provides computational models for these two cases by integrating the characteristics of the extended finite element algorithm, compiles the corresponding computational programs, and verifies the accuracy of the proposed model using numerical comparisons. The model presented in this paper has the advantages of high computational accuracy and stable results in resolving thermal cracking and its propagation in concrete at early ages.

• Corrosion Science and Technology
• /
• v.7 no.4
• /
• pp.219-223
• /
• 2008

In 2006, as a means to minimize early corrosion failure of ships, thus to enhance marine safety, International Maritime Organization (IMO), proposed a mandatory regulation for Performance Standards for the Protective Coatings (PSPC) for ballast tanks of newly built ships to satisfy 15 years of target useful life. In this regulation, several unprecedented strict rules are adopted as minimum, mandatory requirements for protective coatings of ship's water ballast tanks, and all type of ships sailing international sea are subjected to this regulation which is to be effective as early as June of 2008. The PSPC addresses many technical issues in the areas of surface pretreatment (primary and secondary), coating materials, coating application procedure and inspection as well as necessary documentation. The PSPC rules are new and unproven concepts, which calls for rigorous incorporation of reality-based evidences currently available, since there are no practical experiences in terms of the validity of the PSPC rules. There has been much controversy surrounding these regulations and considerable effort has been made by both shipyards and ship owners alike to achieve a performance standard for ballast tank coatings, which is acceptable to all. In this paper, the background and overview of the PSPC rules are given, and several issues in the PSPC are reviewed as a base to achieve robustness of the proposed PSPC, which will serve as a means to minimize early corrosion and to ensure 15 year target useful life of ships.

• Journal of Environmental Policy
• /
• v.2 no.1
• /
• pp.31-49
• /
• 2003

It is difficult to examine the causal relation of pollution damages because the time gap between pollution cause and effect is large and new pollutants are continuously being produced. Their many environmental effects are not promptly studied. As both the study of causal relation about pollution and the pollutant treatment are becoming highly advanced by the development of science and environmental technology, both the economy and balance on environmental regulation may be discussed. It is reasonable to decide environmental policy in consideration of close relation between both the generation and resolution of environmental problems and of technological developments because environmental problems are related to complicated social problems and scientific technologies. First item in policy decision about environmental control and management is preferentially to consider the way of prevention. It is necessary to prevent pollution by regulating the installment of environmental pollution facility into the environmentally sensitive areas, like water supply source and to regulate land utilization as a method to achieve pollution prevention. Second is a consideration of environmental technology development. This is a solution which can accomplish the development of environmental technology and the reinforcement of economic competition. Third is the coexistence of environment and economy. It is necessary to consider economy in connection with environmental problems and environment in economic problem. Then, we can enjoy a healthy life as well as economic affluence. Fourth is the enlargement of environmental management means. Environmental management means must be diversified because environmental cause and effect are varied. For Improving the land use regulation system, it is necessary to consider both land use regulation status and pollutant toxicity with the development of environmental technology. Land use must be approached by classifying land to 3 levels; water source protection zone and water front zone, special zone 1 and 2, rancus and other zones. Land regulation policy to prevent any accident in water source protection zone, waterfront zone, and special zone must be continuously upgraded. However, economical consideration in other zones is required by the development of environmental technology.

• Computers and Concrete
• /
• v.19 no.6
• /
• pp.659-666
• /
• 2017

Based on the Arrhenius equations, several hydration exothermic models that precisely calculate the influence of concrete's self-temperature duration on its hydration exothermic rate have been presented. However, the models' convergence is difficult to achieve when applied to engineering projects, especially when the activation energy of the Arrhenius equation is precisely considered. Thus, the models' convergence performance should be improved. To solve this problem and apply the model to engineering projects, the relationship between fast iteration and proper expression forms of the adiabatic temperature rise, the coupling relationship between the pipe-cooling and hydration exothermic models, and the influence of concrete's self-temperature duration on its mechanical properties were studied. Based on these results, the rapid convergence of the hydration exothermic model and its coupling with pipe-cooling models were achieved. The calculation results for a particular engineering project show that the improved concrete hydration exothermic model and the corresponding mechanical model can be suitably applied to engineering projects.

• Proceedings of the KSRS Conference
• /
• v.1
• /
• pp.483-486
• /
• 2006

The study describes the monitoring of the Bay of Bengal as a ballast water exchangeable sea using MODIS/Aqua-derived diffuse attenuation coefficient (K(490)) synchronized with in situ ballast water sampling and analysis along the LNG carrier's route between Japan and Qatar from 2002 to 2005. Based on the relationship between K(490) and corresponding in situ plankton cell densities, the Bay of Bengal is recognized as a ballast water exchangeable sea to meet the regulation of ballast water performance standard of International Maritime Organization (IMO). Furthermore the Bay of Bengal with more than 200m depth and more than 200 nautical mile distance from shore is extracted based on the regulation of ballast water exchange area of IMO. However, an anomalously high K(490) area is found off the coast of Sri Lanka during the northeast monsoon in 2005, which corresponds higher cell densities than the criterion set by the regulation of IMO. The phenomenon of high cell density in the Bay of Bengal seems to be related with the phytoplankton bloom during the northeast monsoon. Seasonal and annual variability of phytoplankton bloom will be investigated to establish an early routing system for avoiding the high cell density area in advance.

• Journal of the Korean Wood Science and Technology
• /
• v.50 no.5
• /
• pp.338-352
• /
• 2022

Herein, water and ethanol extracts were obtained from the leaves, branches, kernels, and pericarp of Quercus gilva and subsequently analyzed for antioxidant activity and circadian rhythm regulation effects. Candidate components that may affect circadian rhythm and antioxidant activity were investigated to discover potential functional materials. Antioxidant activity was analyzed via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity assays, showing that the hot water extract exhibited higher activity than that of the ethanol extract. In particular, the branch extract showed high antioxidant activity. By measuring total contents of polyphenols, flavonoids, and tannins, the hot water branch extract showed the highest concentrations, highlighting their significant contribution to the antioxidant activity. Examination of the circadian rhythm regulation of each extract showed that the ethanol extract exhibited greater impacts on the circadian rhythm amplitude compared to the water extract. The branch ethanol extract induced circadian rhythm amplitude changes via clock gene Bmal1 expression regulation. Determination of 12 phenolic compound concentrations showed that the branch ethanol extract contained many phenolic compounds, including catechin. This suggests that these com- pounds affected circadian rhythm regulation. In conclusion, the hot water branch extract has potential as an natural antioxidant material, while the corresponding ethanol extract has potential as a functional material for regulating circadian rhythm.