• Korean Journal of Ecology and Environment
• /
• v.48 no.4
• /
• pp.212-218
• /
• 2015

In South Korea, various nature-like fishways recently been installed for use by a wide variety of fish species. However, limited attempts have been made to monitor the fish utilization. The present study was conducted to ascertain the frequencies and patterns of utilization of the fishway installed at Beakjae Weir. We collected fish species that use the fishway by installing a fyke net at the exit of the fishway at least once a month from April 2013 to October 2013. Additionally, in order to identify all fish species that can potentially use the fishway, we investigated the fish fauna downstream to Beakjae Weir (mainstream of the Geum River). We found that 10 species belonging to 2 families used the fishway; this accounted for 64% of the total species inhabiting the mainstream. The species that used the fishway most frequently were Microphysogobio jeoni, followed by Squaliobarbus curriculus and Opsariichthys uncirostris amurensis. The highest number of fish using the fishway was observed in August, which was positively correlated with the water temperature (Spearman rank correlation, $r_s$=0.743, P=0.035). The sizes of the fish using the fishway varied widely, with the total body length ranging from 39 mm to 550 mm. Analysis of the time-dependent utilization frequency revealed that most fish used the fishway during the night (20:00~08:00). Compared to other fishways installed along the Geum River, the fishway installed at Beakjae Weir was used by fewer species and fish. This may be attributed to the structural inadequacy of the fishway, thereby resulting in a low attraction efficiency. Therefore, measures should be adopted to enhance the fishway attraction and passage efficiency. The results of this study can be used to ensure efficient operation and management of the Beakjae Weir fishway as well as serve as basic data for developing and building nature-like fishways tailored to Korean situations.

• KSBB Journal
• /
• v.18 no.3
• /
• pp.211-216
• /
• 2003

The removal yield of dissolved organic matter in drinking water by biological activated carbon (BAC) process was investigated. The tested processes wer raw water-AC process (BAC1), raw water-ozonation-BAC process (BAC2), and raw water-ozonation-coagulation/sedimentation-BAC process (BAC3). The amounts of organic matter was measured as dissolved organic carbon (DOC), ulta-violet radiation at 254 nm wavelength ($UV_{254}$), total nitrogen (T-N), ammonia nitrogen (NH_3$-N), and total phosphate (T-P). As a results, 30.7% DOC was removed by BAC2 process, which showed higher removal efficiency than BAC1 or BAC3 processes. The removal yield of $UV_{254}$ in BAC1, BAC2, and BAC3 processes were observed as 45.3%, 44.6%, 58.4%, respectively. And the removal yield of ammonia nitrogen were 66%, 81%, 29% in each BAC processes. The optimal empty bed contact time (EBCT) of BAC processes was estimated as 10 minute. This study has shown that BAC process combined with ozone treatment was efficient for removing dissolved organic matter in water.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.5
• /
• pp.345-350
• /
• 2012

To investigate the exposure and health risk assessment for the residents near the D-asbestos mine in Chungbuk, Korea. We analyzed asbestos in the 20 ambient air and 23 activity based samples near the mine. The airborne sample results are showed that 8 of 20 samples ranged between 0.0025 to 0.0029 f/cc (fiber per cubic centimeter) and the others were below the detection limit by phase contrast microscopy (PCM). In addition, asbestos fibers were under the detection limit or not being by transmission electron microscopy (TEM). Based on interview and survey targeting the local residents, we made the activity based sampling (ABS) scenarios fit to the conditions of field. At the same time, we calculated the excess lifetime cancer risk (ELCR) of these ABS scenarios according to the ELCR average value and 95% upper confidence limit (UCL). At the case of weed whacking, soil digging and sweeping yard scenario, 95% UCL of ELCR exceeded the $1{\times}10^{-4}$, acceptable risk range for exposure. Based on our study results, it is necessary safety measures such as risk communication, abatement or management of naturally occurring asbestos (NOA).

• Journal of Korean Society of Archives and Records Management
• /
• v.3 no.1
• /
• pp.129-140
• /
• 2003

The ultimate goal of preserving and maintaining the records is to use them practically. The effective use of records should be supported by the reasonable recordskeeping systems and access standards. In this report, I examined the Korean laws and administrative systems related to the public records access issues. After I pointed out major problems of the access laws, the Government Information Opening Act (GOIA), and the problems in practices, I suggested some alternatives for the betterment of the access system. The GIOA established "eight standards of exemption to access" not to open some information to protect national interests and privacy. The Public Records Management Act (PRMA) applies to the archives transferred to "professional archives." The two laws show fundamental differences in the ways to open the public records to public. First, the GIOA deals with the whole information (the records) that public institutions keep and maintain, while the PRMA deals with the records that were transferred to the Government Archives. Second, the GIOA provides with a legal procedure to open public records and the standards to open or not to open them, while the PRMA allows the Government Archives to decide whether the transferred records should be opened or not. Third, the GIOA applies to record producing agencies, while the PRMA applies to public archival institutions. One of the most critical inadequacies of the PRMA is that there are no standards to judge to open the archives through reclassification procedure. The GIOA also suggests only the type of information that is not accessible. It does not specify how long the records can be closed. The GARS does not include the records less than 30 years old as its objects of the reclassification. To facilitate the opening of the archives, we need to revise the GIOA and the PRMA. It is necessary to clearly divide the realms between the GIOA and the PRMA on the access of the archives. The PRMA should clarify the principles of the reclassification as well as reclassifying method and exceptions. The exemption standards of the GIOA should be revised to restrict the abuse of the exemption clauses, and they should not be applied to the archives in the GARS indiscreetly and unconditionally.

• Journal of the Korean Institute of Gas
• /
• v.24 no.2
• /
• pp.1-8
• /
• 2020

Centrifugal pump is a facility that transfers energy to fluid through centrifugal force, which is usually generated by rotating the impeller at high speed, and is a major process facility used in many LNG production bases such as vaporization seawater pump, industrial water and fire extinguishing pump using seawater. to be. Currently, pumps in LNG plant sites are subject to operating conditions that vary depending on the amount of supply desired by the customer for a long period of time. Pumps in particular occupy a large part of the consumption strategy at the plant site, and if the optimum operation condition is not available, it can incur enormous energy loss in long term plant operation. In order to solve this problem, it is necessary to identify the performance deterioration factor through the flow analysis and the result analysis according to the fluctuations of the pump's operating conditions and to determine the optimal operation efficiency. In order to evaluate operation efficiency through experimental techniques, considerable time and cost are incurred, such as on-site operating conditions and manufacturing of experimental equipment. If the performance of the pump is not suitable for the site, and the performance of the pump needs to be reduced, a method of changing the rotation speed or using a special liquid containing high viscosity or solids is used. Especially, in order to prevent disruptions in the operation of LNG production bases, a technology is required to satisfy the required performance conditions by processing the existing impeller of the pump within a short time. Therefore, in this study, the rotation difference of the pump was applied to the ANSYS CFX program by applying the modified 3D modeling shape. In addition, the results obtained from the flow analysis and the curve fitting toolbox of the MATLAB program were analyzed numerically to verify the outer diameter correction theory.

• Food Science and Preservation
• /
• v.20 no.4
• /
• pp.583-591
• /
• 2013

Atopic dermatitis (AD) is a common chronic inflammatory disease associated with a cutaneous hypersensitivity reaction to an allergen. Although the incidence of AD is increasing these days, therapeutics has yet to be developed for its treatment. The aim of this study was conducted in order to compare and investigate the characteristic between the Castanea crenata inner shell extract (CS) and the Castanea crenata inner shell extract fermented by Lactobacillus bifermentans (FCS) for an anti-atopic medication. The total polyphenol and flavonoid contents were similar to CS and FCS. In the DPPH and superoxide anion radical scavenging, the CS and FCS had the potential for antioxidant activities. Both of them did not exhibit cytotoxicity to HS68 cells. The evaluation of the anti-inflammatory activity in Raw264.7 cells demonstrated that the FCS has inhibited the LPS-induced production of nitric oxide as compared to the CS. The anti-atopic dermatitis test was done through the induction of DNCB in AD hairless mice. The FCS has inhibited the development of the atopic dermatitis-like skin lesion by transdermal water loss, melanin and erythema of the skin as compared to the CS. Moreover, the pro-inflammatory cytokine IL-$1{\beta}$ and TNF-${\alpha}$ production in hairless mice were inhibited by the FCS treatment. It indicates that the fermentation of the Castanea crenata inner shell has the potential for the treatment of atopic dermatitis.

• The Journal of Korean Academy of Prosthodontics
• /
• v.46 no.2
• /
• pp.175-184
• /
• 2008

Purpose: This study was designed to investigate the fitness of adjustable dental impression trays on the Chinese and the Japanese. Material and methods: Initial design of the adjustable dental trays was developed from the results of the dental arch size of Korean adults. This design was applied to the CAD-CAM process in order to create tray model samples. Simple silicon-base molds were then replicated based on these sample models. Polyurethane injection into the silicon- base molds completed the process of creating a large number of test products. 60 Chinese dental students (male:30, female:30) from the Shanghai Second Medical University and 60 Japanese alumni from the Kumamoto high school (male:30, female:30) were selected for taking irreversible hydrocolloid impression with these trays. The width and length of the impression body were measured on several measuring points by Vernier caliper. The results were analyzed statistically to evaluate the fitness of the trays. Results: 1. Uniform impression material thickness was achieved on the Chinese and Japanese by controlling the width of the tray using stops and beveled guides. The material thickness was generally within the range of 3 mm to 6 mm. 2. In the maxillary tray of the Chinese, average thickness of the impression material of the labial vestibule of the incisal teeth was 6.2 mm, the canine was 5.9 mm and the midpalatal part 10.5 mm and the posterior palatal part 9.7 mm. These were relatively large values. 3. In the mandibular tray of the Chinese, average length of the impression material of the lingual vestibule of first, second premolar contact point was 8.9 mm, the incisal teeth was 7.8 mm and thickness of the labial part of canine was 6.8 mm and premolars 7.0 mm. These were relatively large values. 4. In the maxillary tray of the Japanese, average thickness of the impression material of the labial vestibule of the incisal teeth was 7.4 mm, the canine was 7.7 mm and the midpalatal part 9.1 mm. These were relatively large values. 5. In the mandibular tray of the Japanese, average thickness of the impression material of the labial vestibule of first, second premolar contact point was 8.4 mm, and thickness of the labial part of canine was 7.4 mm. These were relatively large values. Conclusion: This adjustable dental tray shows good accuracy to Korean because it was designed by the analysis of the dental arch size of Korean adult model. With this result, it can be applied to Chinese and Japanese, we can take more easy and accurate dental impressions.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.24 no.4
• /
• pp.389-403
• /
• 2008

In Angle's Class III malocclusion, which has higher incidence in Korean than Western, depressed midfacial profile with protruded lower lips and mandible may give rise to many functional, esthetic, psychological, social problems. Due to the different malocclusion incidence according to racial differences, many previous studies focused on the relationship between Class II malocclusion and nasal airway obstruction. Previous studies used lateral cephalography which has limitations of 2 dimensional image with projection error and identification error. Therefore, the purpose of this study was to analyze morphologic differences in the nasal airway between normal occlusion and Angle's Class III malocclusion patients using 3-dimensional facial computed tomography. Thirteen normal occlusion(7 men and 6 women) and sixteen skeletal Class III(7 men and 9 women) patients were selected and 3-dimensional facial computed tomography taking was performed. Comparison between two group in volume and sectional area of nasal airway were carried out. The results were followed. 1. In the comparison of absolute nasal airway volume, oropharyngeal space of experimental group were larger than control group but there are no significant difference in other. 2. In the comparison of relative nasal airway volume, oropharyngeal space of experimental group were larger than control group but there are no significant difference in other. 3. In the oropharyngeal space width on frontal and lateral view, the similar tendency was revealed between two groups. 4. In the lateral curvature of nasal airway, the similar tendency was revealed between two groups.

• Journal of Genetic Medicine
• /
• v.8 no.2
• /
• pp.119-124
• /
• 2011

Purpose: Supernumerary marker chromosome (SMC) could be associated with various phenotypic abnormalities based on the chromosomal origin of SMCs. The present study aimed to determine the genomic contents of SMCs using chromosomal microarray and to analyze molecular cytogenetic characterizations and clinical phenotypes in patients with SMCs. Materials and Methods: Among patients with SMCs detected in routine chromosomal analysis, SMCs originating from chromosome 15 were excluded from the present study. CGH-based oligonucleotide chromosomal microarray was performed in 4 patients. Results: The chromosomal origins of SMCs were identified in 3 patients. Case 1 had a SMC of 16.1 Mb in 1q21.1-q23.3. Case 2 showed 21 Mb gain in 19p13.11-q13.12. Case 3 had a 4.5 Mb-sized SMC rearranged from 2 regions of 2.5 Mb in 22q11.1-q11.21 and 2.0 Mb in 22q11.22-q11.23. Conclusion: Case 1 presented a wide range of phenotypic abnormalities including the phenotype of 1q21.1 duplication syndrome. In case 2, Asperger-like symptoms are apparently related to 19p12-q13.11, hearing problems and strabismus to 19p13.11 and other features to 19q13.12. Compared with cat-eye syndrome type I and 22q11.2 microduplication syndrome, anal atresia in case 3 is likely related to 22q11.1-q11.21 while other features are related to 22q11.22-q11.23. Analyzing SMCs using high-resolution chromosomal microarray can help identify specific gene contents and to offer proper genetic counseling by determining genotype-phenotype correlations.

• Resources Recycling
• /
• v.29 no.2
• /
• pp.55-61
• /
• 2020

Selective catalytic reduction (SCR) has been a promising technology to reduce the air pollution caused by nitrogen oxides (NOx) in several industries. The consumption of SCR catalysts increases every year as technology evolves, however those have a limited lifespan and usually end up in landfills after they deactivate. Currently, the most widely used catalyst for and stationary applications is V₂O₅-WO₃/TiO₂ which can contain around 50% wt V₂O₅ and 7-10% wt of WO₃. The vast uses for both vanadium and tungsten and the worldwide interest in recycling methods that allow for the extraction of metals from secondary sources represent the major motivation for this research. The extraction time, pH dependency, extraction concentration studies were carried out using Aliquat 336 in exxol D80 as the extractant. It was determined that to optimize the extraction of both metals 30min of contact time with an organic phase containing 0.5mol/L of Aliquat 336 are needed at a slightly acidic pH (~5.0). In addition, counter McCabe-Thiele studies allowed us to determine that one stage is necessary for the removal of 99% of vanadium while 2 stages are necessary for the extraction of tungsten and counter current simulations proved that the theoretical approach was correct.