• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.2
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• pp.127-137
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• 2019

Zr electrorefining is demonstrated herein using Zirlo tubes in a chloride-fluoride mixed molten salt in the presence of $AlF_3$. Cyclic voltammetry reveals a monotonic shift in the onset of metal reduction kinetics towards positive potential and an increase in intensity of the additional peaks associated with Zr-Al alloy formation with increasing $AlF_3$ concentration. Unlike the galvanostatic deposition mode, a radial plate-type Zr growth is evident at the top surface of the salt during Zr electrorefining at a constant potential of -1.2 V. The diameter of the plate-type Zr deposit gradually increases with increasing $AlF_3$ concentration. Scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX) and X-ray photoelectron spectroscopy (XPS) analyses for the plate-type Zr deposit show that trace amount of Al is incorporated as Zr-Al alloys with different chemical compositions between the top and bottom surface of the deposit. Addition of $AlF_3$ is effective in lowering the residual salt content in the deposit and in improving the current efficiency for Zr recovery.

• Journal of Environmental Health Sciences
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• v.47 no.1
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• pp.64-77
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• 2021

Objective: Biological monitoring of trace elements in human blood samples has become an important indicator of the health environment. The purpose of this study was to detect and evaluate multiple metal items in blood samples based on ICP-MS, to perform comparative evaluation with the existing analysis method, and to develop and verify a new method. Methods: 100 μL of whole blood from 80 healthy subjects was used to analyze ten metals (Sb, tAs, Cd, Pb, Mn, Hg, Mo, Ni, Se, Tl) using ICP-MS. Verification of the analysis method included calculation of linearity, accuracy, precision and detection limits. In addition, a comparative test with the conventional graphite furnace atomic absorption spectroscopy (GF-AAS) method was performed. In the case of Pb, Cd, and Hg in whole blood, cross-analysis between Pb, Cd, and Hg analysis methods was performed to confirm the difference between the existing method and the new method (ICP-MS). Results: The coefficient of determination (R2) was 0.999 or higher in seven items and 0.995 or higher in three items. The Pb result showed that Pearson's correlation coefficient was very high at 0.983, and the intraclass correlation coefficient was 0.966. The Cd result showed that Pearson's correlation coefficient was 0.917 between the existing method and the new analysis concentration value. Its intraclass correlation coefficient was 0.960, and there was no significant difference between the two groups. Hg had a low correlation at 0.687, and the intraclass correlation coefficient was 0.761, which was lower than that of Pb and Cd. The intra-day and inter-day accuracy of Pd and Cd were satisfactory, but Hg did not meet the criteria for both accuracy and precision when compared with the conventional analysis method. Conclusion: This study can be meaningful in that it proposes a more efficient and feasible analysis method by verifying a blood heavy metal concentration experiment using multiple simultaneous analyses. All samples were processed and analyzed using the new ICP-MS. It was confirmed that the agreement between the two methods was very high, with the agreement between the current and new methods being 0.769 to 0.998. This study proposes an efficient simultaneous methodology capable of analyzing multiple elements with small samples. In the future, studies of various applications and the reliability of ICP-MS analysis methods are required, and research on the verification of accurate, precise, and continuous analysis methods is required.

• Journal of Nutrition and Health
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• v.55 no.4
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• pp.430-440
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• 2022

Selenium is an important trace mineral that plays an essential role in maintaining the body's immunity with oxidative stress defense and antioxidant activity, immunity, thyroid hormone control, defense against drug or heavy metal harm, and reducing the risk of chronic diseases. A selenium deficiency increases the risk of various chronic diseases, such as cancer, cardiovascular disease, diabetes, neurological disease, osteoarthritis, muscle necrosis and weakness, thyroid disease, and inflammatory diseases. This paper explains the criteria for establishing and revising selenium in the 2020 Dietary Reference Intake for Koreans (KDRIs) and reviews the current status of the selenium database and suggestions for setting the 2025 KDRIs in the future. In the 2020 KDRIs, the selenium intake with the maximum plasma selenoprotein P level was used as the criteria. The weight and coefficient of the variation were applied to the Chinese' reported values. Compared to 2015 KDRIs, there were some revisions in the selenium dietary reference intakes by gender and age according to the change in reference weight. To improve and revise selenium dietary reference intakes in the future, a selenium intervention study is needed to determine the maximum level of plasma selenoprotein P in Koreans. In addition, a revision of the selenium database of the nutritional assessment program (CAN-Pro 5.0) is needed. An analysis of the selenium content of foods should be expanded to assess the selenium intake accurately. In addition, research on the relationship between selenium intake and the biological indicators in the body is required for healthy people and subjects of special environments, such as patients and athletes with various oxidative stress.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2D
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• pp.235-244
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• 2009

Design Value Engineering (VE) has become an import part of the daily design process since it has been introduced in the construction industry. Design VE is usually conducted in the general and execution design stages respectively. In order to increase the effectiveness of the VE process, the outcome from the general design VE activities should be integrated into execution design. The outcome from the execution design should be used again for construction. In this study, a consecutive VE process model has been presented as a way to improve the current practice of design VE activities in the construction industry. In the presented model, follow-up activities are emphasized to increase values from the life-cycle perspective of a construction project. The model was tested in a case study of an actual design VE process. The result of the study demonstrates that the model can: 1) effectively incorporate owners requirements; 2) assist decision making in selecting better construction; 3) increase the interface between general and execution design stages; and 4) trace the value flow more efficiently. Overall, the study results indicates that a the consecutive VE process model can be effectively applied when construction project are contracted for the life-cycle management of construction projects.

• Journal of the Mineralogical Society of Korea
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• v.31 no.1
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• pp.1-12
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• 2018

A gravity core (RS14-C2) was collected at site RS14-C2 in the continental slope to the east of Pennell-Isellin Bank of the Ross Sea (Antarctica) during PNRA XXIX (Rosslope II Project) Expedition. In order to trace the sediment source, magnetic susceptibility (MS), sand fraction, and clay mineral compositions were analyzed, and AMS $^{14}C$ ages were dated. Core sediments consist mostly of hemipelagic sandy clay or silty clay including ice-rafted debris (IRD). AMS $^{14}C$ age of core-top indicates the modern and Holocene sediments. Based on AMS $^{14}C$ dating, sediment color, MS and sand fraction, core sediments are divided into interglacial and glacial intervals. The interglacial brown sediments are characterized by low MS and sand fraction, whereas the glacial gray sediments are characterized by high MS and sand fraction. Among clay mineral compositions of core sediments, illite is highest (61.8~76.7%), and chlorite (15.7~21.3%), kaolinite (3.6~15.4%), and smectite (0.9~5.1%) are in decreasing order, and these compositions are also divided into the interglacial and glacial/deglacial intervals. During the glacial period, the high content of illite and chlorite indicate sediment supply from the bedrocks of Transantarctic Mountains under the Ross Ice Sheet. In contrast, because of decreasing supply of illite and chlorite by the glacial retreat, smectite and kaolinite contents increased relatively during the interglacial period. During the interglacial period, smectite may be transported additionally by the northeastward flowing surface current from the coast of Victoria Land in the western Ross Sea. Kaolinite may be also supplied to the continental slope by the Antarctic Slope Current from the kaolin-rich metasedimentary rock outcropped on the Edward VII Peninsula.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.2
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• pp.108-121
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• 2016

The purpose of this study is to explore the issues and implications for landscape design education in Korean landscape architecture by analyzing the National Exhibition of Korean Landscape Architecture(NEKLA). This study analyzed the suggested topics and selected site as well as the commentary that appeared in the NEKLA's award-winning book published from 2004 to 2014. Results of the study are as follows: First, topics of NEKLA are not only competition guidelines but related to exploring new area and role of Korean landscape architecture. Second, most dealing with site is 'industrial heritage and regeneration space' and 'green infrastructure'. In more recent years, a larger variety of sites were addressed. Third, site locations are concentrated in metropolitan areas, and awards and participation of the non-metropolitan universities was very low. Fourth, seven criteria can be applied in a general landscape design competition such as 'newness of the concept(idea)', 'logicality of the design process', 'selection of site fidelity of analysis(interpretation)', 'presentation and completion of the master plan', 'consistency with the theme', 'linkage of concepts and results' and 'feasibility'. The evaluation criteria are increasing the sophistication of the design language to provide useful suggestions on how to find design education methods. Its implications are as follows: First, training is essential to derive innovative ideas, but it should avoid excessive concept-oriented education. Second, design education may include instruction on how to define the problems related with the site. Third, more emphasis on design logic is essential to transform the innovative concept to actual results. Fourth, 'slick images' unrelated to design should be suppressed. Fifth, practice is needed to solve the topics addressed in the design process of education. Sixth, 'feasibility' and 'creative thinking' are necessary to recognize a reciprocal relationship that is helpful to one another. This study uses direct quote commentary to minimize the subjectivity of the researcher and to trace issues of the contemporary landscape architecture more directly and vividly. This study is a record waiting for another review as meta-criticism. In this regard this study, the landscape architect of the next times will have a mean that historical records to review the current thinking of the landscape theory and design.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.3
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• pp.25-37
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• 2013

The purpose of this study is to draw reasonable management plans to reinforce essence of Ohyundan(五賢壇: Five sprit tablets), a sacred site and monument of Jeju, by investigating and analyzing current status and problems of cultural landscape elements(e.g. architectural structures, installation, letters carved on the rocks, actual vegetation, etc.) while grasping placeness contained in Ohyundan through consideration of its history and transition process of Ohyundan a future being and shrine of Gyulrim Seowon(橘林書院) in Jeju. Results derived from research are summarized as follows. Ohyundan is noted due to its placeness in that it was a place for Gyulrim Seowon, Jeju's one and only Saaek Seowon(賜額書 院) and it was a symbolic space of exile culture in Jeju. As it is inferred from Gyulrim Seowon, which is dangho(堂號: clan name) of Seowon, orchards surrounding all over places are a signature landscape element that shows placeness of the past Ohyundan. Joduseok(俎豆石: altar stone), representing a core installation of Ohyundan and ancestral tablet of five spirits, created a refined place by putting up common stones around altar and founding blocked stones to wall. This refinement and thrift served basic mind of Neo-Confucianism, and led to of Jeju's Jonyang mind(spend-thrift mind). In conclusion, a practice plan is a prerequisite to restore essence of Ohyundan by actively excluding installations not suitable for placeness or overly designed such as Jeju Hyangrodang(a center for the elderly) and numerous monument houses. On the other hand, together with Joduseok, as letters carved on the rocks such as 'Jeungjoo Byukrip(曾朱壁立)' and 'Gwangpoongdae(光風臺)' and Yoocheonseok serve as a signature landscape that well shows mind of five spirits and teaching of Neo-Confucianism, and also a trace from a confucian viewpoint deeply rooted in Jeju, they are judged as a cultural landscape corresponding to the essence of place in Ohyundan which requires proactive preservation and plans for public relations. Together with this, although many different old big trees such as Pinus densiflora , Pinus thunbergii, Quercus variabilis, Celtis sinenis, Zelkova serrata and Rhus succedanea are a landscape element that increases sacred Ohyundan and commemorative value, now required is thorough entity tree management by assigning serial number on them as many of them were dead or removed resulting from transition process of land use. Further, to reinforce quality of site location belonging to Gyulrim Seowon, a prerequsite is to review plans that create Gyulrim at reinstalled site of building and raw land.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.175-185
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• 2000

This paper described on a basic study to organize fishing vessel control system in order to control efficiently fishing vessel in Korean offshore. It was digitalized ARPA image on the fishing processing of a fleet of purse seiner in conducting fishing operation at Cheju offshore in Korea as a digital camera and then simulated by used VTMS. Futhermore, it was investigated on the application of FVTMS which can control efficiently fishing vessels in fishing ground. The results obtained were as follows ; (1) It was taken 16 minutes and 35 minutes to casting and hauling net in fishing processing respectively. The length of rope pulled by scout boat was 200m, tactical diameter in casting net was 340.8m, turning speed was 6kts as well. (2) The processing of casting and hauling net was moved to SW, NE as results of simulation when the current direction and speed set into NE, 2kts and SW, 2kts respectively. Such as these results suggest that can predict to control the fishing vessel previously with information of fishing ground, fishery and ship's maneuvering, etc. (3) The control range of VTMS radar used in simulation was about 16 miles. Although converting from a radar of the control vessel to another one, it was continuously acquired for the vector and the target data. The optimum control position could be determined by measuring and analyzing to distance and direction between the control vessel and the fleet of fishing vessel. (4) The FVTMS(fishing vessel traffic management services) model was suggested that fishing vessels received fishing conditions and safety navigation information can operate safely and efficiently.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.257-267
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• 2014

The distributions of trace metals in the East Sea were investigated during the R/V Lavrentyev cruise (July 2009) in which four transects from Russia shore to South were conducted to collect 25 surface water samples. The total dissolved concentrations of Cu and Ni were measured using ICP-MS, DRC-e. In the coastal area, their concentrations of Russia shore (Cu, 1.51; Ni, 1.82 nM) were 1.9 times for Cu and 2.0 times for Ni lower than Korea shore (Cu, 2.87; Ni, 3.71 nM). In the subregion, their concentrations of Warm region (Cu, 3.03; Ni, 2.28 nM) were higher for Cu than Cold region (Cu, 2.04; Ni, 2.28 nM). The distributions of Cu and Ni concentrations were divided by lowest level at $10^{\circ}C$ of water temperature. In this study period, the surface water temperatures of Russia shore and Japan basin were lower than $10^{\circ}C$ and them of Ulleung basin and Sakhalin shore were higher. Below $10^{\circ}C$, Cu and Ni concentrations increased when surface water temperatures decreased. Above $10^{\circ}C$, their concentrations increased with temperature, which showed highest concentrations in the Ulleung basin, directly influenced by flux from East Korean Warm Current. By comparing with other sea areas (Western Mediterranean, Atlantic), Cu concentrations in the East Sea were a little higher and Ni concentrations were lower. Particularly as the level of Cu in the offshore in the Ulleung basin were higher than in the coastal area, We can suggest that the atmospheric flux of Cu is relatively important in this area.

• Ocean and Polar Research
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• v.36 no.1
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• pp.13-24
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• 2014

We established the first complete ice core processing method and analytical procedures for fundamental proxies, using a 40.2 m long ice core drilled on the Mt. Tsambagarav glacier in the Mongolian Altai mountains in July 2008. The whole core was first divided into two sub ice core sections and the measurements of the visual stratigraphy and electrical conductivity were performed on the surface of these sub core sections. A continuous sequence of samples was then prepared for chemical analyses (stable isotope ratios of oxygen ($^{18}O/^{16}O$) and hydrogen ($^2H/^1H$), soluble ions and trace elements). A total of 29 insoluble dust layers were identified from the measurement of visual stratigraphy. The electrical conductivity measurement (ECM) shows 11 peaks with the current more than 0.8 ${\mu}A$ Comparing the profiles of $SO_4{^{2-}}$ and $Cl^-$ concentrations to correlate with known volcanic eruptions, the first two ECM peaks appear to be linked to the eruptions (January and June 2007) of Kliuchevskoi volcano on the Kamchatka Peninsula of Russia, which supports the reliability of our ECM data. Finally, the composition of stable isotopes (${\delta}^{18}O$ and ${\delta}D$) shows a well-defined seasonal variation, suggesting that various chemical proxies may have been well preserved in the successive ice layers of Tsambagarav ice core. Our ice core processing method and analytical procedures for fundamental proxies are expected to be used for paleoclimate and paleoenvironmental studies from polar and alpine ice cores.