• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.689-698
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• 2000

The quality of stormwater runoff has been a major concern in water quality preservation. Characteristics of heavy metals and conventional pollutants in surface runoff from industrial complex, during the first flush, were not completely understood, Generally, separated sewer system is known for their water quality with untreated wastewater during storm events. In this study, the quality and characteristics of surface runoff from the industrial complex were investigated. The target area in the industrial complex catchment was divided 4 sub-areas, and the quality of stormwater runoff from the selected drainage areas was investigated using a grab sampling method. The petro-chemical industry and the junkyard discharged relatively high concentration of conventional pollutants, such as BOD, COD, SS, and TN through the first flush runoff samples. On the other hand, a higher level of heavy metals was found in the first flush runoff from the metal-mechanical industry and the scrap storage yard. For metals, Fe, Zn and Cu were the most prevalent species found in the first flush runoff from all sites for every surface runoff samples, while Pb, As, Cd, Cr and Ni were the least prevalent species and Hg was not found in any sample at any site. These results suggest that the nature of pollutants in surface runoff from the industrial complex was related to the type of industry, and the concentration of pollutants was determinated by the degree of exposed pollutant sources and the characteristic of rainfall events at the sites.

• Journal of Korea Water Resources Association
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• v.53 no.9
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• pp.681-690
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• 2020

Generally, the design capacity of the rainwater harvesting unit is determined by trial and error method that is repeatedly calculating various analysis scenarios with capacity, reliability, and rainwater utilization ratio, etc. This method not only takes a lot of time to analyze but also involves a lot of calculations, so analysis errors may occur. In order to solve the problem, this study suggested a way to directly determine the minimum capacity to meet arbitrary target reliabilities using the global optimization method. The method was implemented by simulation model with particle swarm optimization (PSO) algorithms using Python language. The pyswarm that is provided as an open-source of python was used as optimization method, that can explore global optimum, and consider constraints. In this study, the developed program was applied to the design data for the rainwater harvesting constructed in Cheongna district 1 in Incheon to verify the efficiency, stability, and accuracy of the analysis. The method of determining the capacity of the rainwater harvesting presented in this study is considered to be of practical value because it can improve the current level of analytical technology.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.2
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• pp.195-202
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• 2018

As a rule, geological disposal is considered a safe method for final disposal of high-level radioactive waste. However, some long-lived fission products like $^{99}Tc$ and $^{129}I$ contained in spent nuclear fuel are highly mobile as less sorbing anionic species in the subsurface environment and can mainly cause exposure dose to the ecosystem by emission of beta rays in the hundreds of keV range. Therefore, if these two nuclides can be separated and converted with high efficiency into radioactively unharmful nuclides, this would have a positive effect on disposal safety. One candidate method is to transmute these two nuclides in nuclear reactors into short-lived nuclides or into stable nuclides. For this purpose, it is necessary to evaluate which reactor type is more efficient in burning these two nuclides. In this study, the simulation results of nuclear transmutation of $^{99}Tc$ and $^{129}I$ in light water reactor (PWR), heavy water reactor (CANDU) and fast neutron reactor (SFR, MET-1000) are compared and discussed.

• The Korea Journal of Herbology
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• v.36 no.2
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• pp.1-9
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• 2021

Objectives : Gossypium arboreum (cotton) is traditionally used to treat various health disorders. However, anti-amnesic effect of G. arboreum has not been reported. The objective of this study was to investigate in-vivo the anti-amnesic effects along with in vitro antioxidant and acetylcholinesterase (AChE) inhibition potential in G. arboreum seed essential oil. Methods : The essential oil of G. arboreum obtained by solid phase microextraction (SPME) techniques were identified by gas chromatography-mass spectroscopy (GC-MS). 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay were performed to determine the antioxidant activity at various concentrations (312.5, 625, 1250, 2500, 5000, 10000 ㎍/㎖. Y-maze, passive avoidance and Morris water maze tests were carried out to evaluate improved effect on scopolamine (1 mg/kg)-induced memory dysfunction at the dose level of 50, 100 and 200 mg/kg. Donepezil (5 mg/kg) was used as a positive drug control. We performed acetylcholinesterase (AChE) activity assay in ex vivo. Results : Five volatile compounds were identified in G. arboreum. The assays of DPPH and ABTS revealed that G. arboreum increased antioxidant activity in a dose-dependent manner. G. arboreum ameliorated the percent of spontaneous alternation in the Y-maze test, shortened step-through latency in the passive avoidance test, and increased swimming time in the target zone in the Morris water maze test. In addition, G. arboreum inhibited the AChE activity. Conclusions : Based on these findings, G. arboreum may aid in the prevention and treatment of learning and memory-deficit disorders through antioxidant and AChE inhibitory activities.

• Journal of Physiology & Pathology in Korean Medicine
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• v.35 no.3
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• pp.97-103
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• 2021

Perilla frutescens (P. frutescens) is an important herb used for many purposes such as medicinal, aromatic, and functional food in Asian countries and has beneficial effects such as antioxidant activity, anti-inflammation activity, anti-depression activity, and anxiolytic activity. However, there have been no studies on the protective effect of P. frutescens extract (PFE) on amnesia in vivo. The present study aimed to investigate whether PFE protects memory deficit using a scopolamine-induced mice model and elucidate the underlying mechanisms involved. The protective effect of PFE against scopolamine-induced memory deficits was investigated using Y-maze, passive avoidance, and Morris water maze tests. Furthermore, the potential mechanisms of PFE in improving memory capabilities related to the cholinergic system and antioxidant activity were examined. PFE significantly increased spontaneous alternation in the Y-maze test, step-through latency in the passive avoidance test, and swimming time in the target quadrant in the probe test when compared to the scopolamine-treated group. Likewise, PFE significantly decreased escapes latency in the Morris water maze test. PFE could not regulate cholinergic function in acetylcholine level and acetylcholine esterase activity. However, PFE increased DPPH radical scavenging activity dose-dependently and total polyphenol content was 127.7±1.2 ㎍ GAE/mg. The results showed that the PFE could be a preventive and/or therapeutic candidate for memory and cognitive dysfunction in Alzheimer's disease.

• Journal of Wetlands Research
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• v.24 no.3
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• pp.204-212
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• 2022

The LID technique began to be applied in Korea after 2009, and LID facilities are installed and operated for rainwater management in business districts such as the Ministry of Environment, the Ministry of Land, Infrastructure and Transport, and LH Corporation, public institutions, commercial land, housing, parks, and schools. However, looking at domestic cases, the application cases and operation periods are insufficient compared to those outside the country, so appropriate design standards and measures for operation and maintenance are insufficient. In particular, LID facilities constructed using LID techniques need to maintain the environment inside LID facilities because hydrological and environmental effects are expressed by material circulation and energy flow. The LID facility is designed with the treatment capacity planned for the water circulation target, and the proper maintenance, vegetation, and soil conditions are periodically identified, and the efficiency is maintained as much as possible. In other words, the soil created in LID is a very important design element because LID facilities are expected to have effects such as water pollution reduction, flood reduction, water resource acquisition, and temperature reduction while increasing water storage and penetration capacity through water circulation construction. In order to maintain and manage the functions of LID facilities accurately, the current state of the facilities and the cycle of replacement and maintenance should be accurately known through various quantitative data such as soil contamination, snow removal effects, and vegetation criteria. This study was conducted to investigate the current status of LID facilities installed in Korea from 2009 to 2020, and analyze soil changes through the continuity and current status of LID facilities applied over the past 10 years after collecting soil samples from the soil layer. Through analysis of Saturn, organic matter, hardness, water contents, pH, electrical conductivity, and salt, some vegetation-type LID facilities more than 5 to 7 years after construction showed results corresponding to the lower grade of landscape design. Facilities below the lower level can be recognized as a point of time when maintenance is necessary in a state that may cause problems in soil permeability and vegetation growth. Accordingly, it was found that LID facilities should be managed through soil replacement and replacement.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.113-119
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• 2019

Concrete structures built on reclaimed land are combined with chemical erosion such as chlorine and sulfate ions from seawater. Chloride attack deteriorates the performance of the structure by corroding reinforcing bars. In addition, the waste water treatment structure has a problem that the concrete is deteriorated by the sulfate generated inside. Therefore, in this study, the characteristics and chemical resistance of low heat cement concrete used in wastewater treatment structures constructed on reclaimed land were evaluated. As a result of the experiment, the target slump and air content were satisfied under all the mixing conditions. The slump of low heat cement (LHC) concrete was higher than that of ordinary portland cement (OPC) concrete, while the air content of LHC concrete was smaller than that of OPC concrete with the same mix proportion. As a result of compressive strength test, OPC concrete showed higher strength at younger age compared to 28 days. In contrast, LHC concrete exhibited higher strength than OPC concrete at the age of 56 days. As a result of chlorine ion penetration tests, LHC-B concrete showed chlorine ion penetration resistance performance of the "very low" level at the age of 56 days. As a result of chemical resistance evaluation, when the LHC concrete is applied without epoxy treatment, chemical resistance is improved by about 18% compared to OPC concrete. In testing chemical resistance, the epoxy coated concrete exhibited less than 5% strength reduction when compared to sound concrete.

• Journal of the Korea Concrete Institute
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• v.29 no.4
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• pp.379-387
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• 2017

The objective of this study is to develop sustainable PVA fiber-reinforced cementitious composites (FRCCs) that could exhibit comparable strength level to normal PVA FRCCs with no recycled materials. To evaluate mechanical properties of the FRCCs, compressive, flexural and direct tensile tests were conducted. In addition to the test, to calculate amount of carbon dioxide ($CO_2$) emission at the stage of manufacturing the FRCCs, life cycle inventory data base (LCI DB) were referenced from domestic and Japan. From the test results, the mechanical properties such as compressive, flexural and direct tensile strengths were decreased as the replacement ratio of recycled materials increased. And it was determined that the amount of $CO_2$ emission was reduced for the specimens with higher water-binder ratio (W/B) and replacement ratios. It was also found that binder intensity ($B_i$) value was higher as replacement ratio of fly ash (FA) increased. This result means that larger amount of FA is need to deliver one unit of a given performance indicator (1 MPa of strength) of FRCCs compared to that of ordinary portland cement (OPC). As a result, it could be concluded that FRCCs with W/B 45% replaced by FA 25% and recycled sand (RS) 25% is desirable for both target performance and $CO_2$ emission.

• Journal of dental hygiene science
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• v.7 no.4
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• pp.281-286
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• 2007

The purpose of this research was to find out their perception of the dental hygiene and level of its knowledge by estimating status of senior adults' dental health management. First, questionnaires were distributed to the 256 target senior adults aged more than 60, who were going to school for senior adults located in Ulju Country and the survey was conducted by interview directly. The results were as follows; 1. As for tooth brushing method, scrubbing method was used in male and rolling method was used in female and the survey results statistically revealed that rolling method was the most used in aged from 60 to 70(68.1%) and scrubbing method was the most used in aged more than 70(80.4%)[p < 0.001]. 2. As for reason of visiting dental clinic, female respondents accounting for the highest said they visited dental clinic when they feel a pain in the teeth and as for frequence of dental clinic, male respondents visited dental clinic for a once per a year. there was no difference statistically according to age(47.9%). 3. As for the perception of the necessity of dental prosthetic treatment, there was higher positive response in the female than male, in the lower aged groups than higher aged group[p<0.05]. 4. As for the question of whether to use of denture or not now, the survey results was statistically that the higher aged group and male groups were higher used dentures [p < 0.001]. 5. As for maintenance of denture, female respondents said the highest that they keep it in cold water after cleaning(95.5%), there was no difference statistically according to age and educational background [p < 0.001].

• The Journal of Engineering Geology
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• v.19 no.3
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• pp.295-306
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• 2009

The risk assessment of groundwater and soil in Sasang industrial complex in Busan Metropolitan City was carried out in order to estimate risks to human health and the environment. The carcinogenic risk (CR) of receptors to soil and air was not identified. However, the CRs for TCE and PCE were 6.7E-6 and 1.0E-5, respectively. Hazard quotient (HQ) and hazard index (HI) did not appear through air exposure pathways. Yet the HQ and HI of soil were 3.4E-5 and 5E-5, respectively, and lower than the critical value (1.0). On the contrary, HQ and HI with respect to groundwater were calculated as 0.7 (not hazardous) and 1.4 (hazardous). The constituent reduction factor (CRF) for TCE in the study area was determined as 2.5, and thus remediation work is demanded. As a result of sensitivity analysis for 18 exposure factors, eight exposure factors (life time of carcinogens, age, body weight, exposure duration, exposure frequency, dermal exposure frequency, water ingestion rate, and soil ingestion rate) varied with the variation of risk.