• Resources Recycling
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• v.33 no.3
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• pp.3-11
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• 2024

This study addressed the cost structure of metallurgical plants for vanadium recovery or production, which were previously planned or implemented. Vanadium metallurgy consists of several sub-processes such as such as pretreatment, roasting, leaching, precipitation, and filtration, in order to finally produce vanadium pentoxide. Here, lots of costs should be spent for such plants, in which these costs are largely divided into CAPEX (Capital Expenditure) and OPEX (Operational Expenditure). As a result, the capacities (feed input rates) and vanadium contents are various along the target projects for this study. However, final production rates and grades of vanadium pentoxide showed relatively small differences. In addition, a noticeable correlation is found between capacities and specific operating costs, in that a steadily decreasing trend is described with a non-linear curve with around -0.3 power. Therefore, for the plant capacity below 100,000 tons per year, the specific operating cost rapidly decreases as the capacity increases, whereas the cost remains relatively stable in the range of 0.6 to 1.2 million tons per year of the capacity. From a technical perspective, effective optimization of the metallurgical process plant can be achieved by improving vanadium recovery rate in the pre-treatment and/or roasting-leaching processes. Finally, the results of this study should be updated through future research with on-going field verification and further detailed cost analysis.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.4
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• pp.340-347
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• 2024

In this study, an expert survey was conducted using the Delphi technique to select items and indicators for evaluation before installing educational facilities in the marine fisheries safety field, in which the educational infrastructure gap between regions is wide. Seven indicators were selected as geographic, social, and administrative factors. In order to objectively evaluate each indicator, evaluation indicators that could be evaluated using public data such as the "Comprehensive National Balanced Development Information System" and "National Statistical Portal" were developed. The Analytic Hierarchy Process (AHP) method was applied to select the weight for each indicator, resulting in 10 most important influencing factors on the selection of the location of educational facilities of the Marine Fisheries Safety Education Facilities: the distribution of marine officers, access to high-speed railways, the number of small ships less than 5 tons, access to highways interchange, the distribution of fishing boats, the close relationship of related industries, the planned new port, the distribution of commercial ports, the number of marine leisure riders, and the availability of long-term land leases in local government councils. The location evaluation index of marine and fishery safety education facilities developed in this study can be used to evaluate each region using national public data, and has the advantage of enabling objective evaluation. Therefore, it is judged that this evaluation index can be used to verify the feasibility of installing marine fisheries safety education facilities as well as other marine-related facilities.

• Journal of Radiation Industry
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• v.17 no.4
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• pp.345-357
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• 2023

Nuclear forensics has been understood as a mendatory component in the international society for nuclear material control and non-proliferation verification. Radiochronometry of nuclear activities for nuclear forensics are decay series characteristics of nuclear materials and the Bateman equation to estimate when nuclear materials were purified and produced. Radiochronometry values have uncertainty of measurement due to the uncertainty factors in the estimation process. These uncertainties should be calculated using appropriate evaluation methods that are representative of the accuracy and reliability. The IAEA, US, and EU have been researched on radiochronometry and uncertainty of measurement, although the uncertainty calculation method using the Bateman equation is limited by the underestimation of the decay constant and the impossibility of estimating the age of more than one generation, so it is necessary to conduct uncertainty calculation research using computer simulation such as Monte Carlo method. This highlights the need for research using computational simulations, such as the Monte Carlo method, to overcome these limitations. In this study, we have analyzed mathematical models and the LHS (Latin Hypercube Sampling) methods to enhance the reliability of radiochronometry which is to develop an uncertainty algorithm for nuclear material radiochronometry using Bateman Equation. We analyzed the LHS method, which can obtain effective statistical results with a small number of samples, and applied it to algorithms that are Monte Carlo methods for uncertainty calculation by computer simulation. This was implemented through the MATLAB computational software. The uncertainty calculation model using mathematical models demonstrated characteristics based on the relationship between sensitivity coefficients and radiative equilibrium. Computational simulation random sampling showed characteristics dependent on random sampling methods, sampling iteration counts, and the probability distribution of uncertainty factors. For validation, we compared models from various international organizations, mathematical models, and the Monte Carlo method. The developed algorithm was found to perform calculations at an equivalent level of accuracy compared to overseas institutions and mathematical model-based methods. To enhance usability, future research and comparisons·validations need to incorporate more complex decay chains and non-homogeneous conditions. The results of this study can serve as foundational technology in the nuclear forensics field, providing tools for the identification of signature nuclides and aiding in the research, development, comparison, and validation of related technologies.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.557-569
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• 2023

Amphibians are the world's most threatened group of animals, with approximately 41% facing extinction. Contrary to this global trend, the number of amphibian species in Korea has increased by approximately 53.3% over the past 20 years. In particular, salamanders within the genus Hynobius showed even greater diversity, with the number increasing three-fold from two species to seven. However, morphological and ecological traits required for the clear differentiation of these animals are yet to be determined, leading to much confusion. In this study, we investigated the validity of using size traits for species identification, as this method is currently considered a rule of thumb when differentiating Geoje salamanders (Hynobius geojeensis), cryptic Uiryeong salamanders (H. perplicatus), and Korean small salamanders (H. unisacculus). Our study revealed that sex, study period, and habitat were all factors associated with significant differences in snout-vent length, head width, and body weight. Differences in these size traits were evident both between and within species. Our results show that body size traits applied in the recent classification of the three new salamander species could not be seen as a suitable criterion. Such identification methods based solely on body size not only cause great confusion in the field but will also limit future research on Korean Hynobius salamanders.

• Journal of Science Education
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• v.48 no.2
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• pp.91-100
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• 2024

The use of smart devices in science classes has brought about positive changes, such as increased student participation and more self-directed learning. Smart devices are increasingly being used in science classes, creating a need to develop lesson models that can stimulate students' interest and encourage active, self-directed learning in scientific inquiry and experimental activities. In smart education, smart devices and applications play a major role. However, in the "Mixture Separation" section of middle school science, chromatography focuses mainly on paper chromatography, which is not currently used in the field of actual research. This approach is not well-suited for students preparing for a new future society, and it is becoming obsolete due to curriculum revisions. Although chromatography can be used as an activity for career exploration, removing it is not convincing. The advantage of using thin-layer chromatography (TLC), which is employed in actual research, is that it is inexpensive and easy to use in classroom settings. In this study, we have developed a new, faster, and simpler analysis method for TLC that uses smart devices for both qualitative and quantitative analysis. We hope this method will enhance student engagement and facilitate small-scale learning by integrating smart devices into learning activities, making it a practical tool for actual school settings.

• Journal of Ecology and Environment
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• v.48 no.3
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• pp.319-342
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• 2024

Background: The current study is the first quantitative ethnobotanical evaluation of Fateh Pur Thakyala, an unexplored area of Azad Kashmir, Pakistan. The exploration and quantification of ethnobotanical knowledge among people of the study area mainly focused during field survey. The study likely focuses on documenting and preserving the indigenous knowledge and practices related to medicinal plants in the region. A total 70 informants (45 males and 25 females) selected randomly to collect data were interviewed using semi structured questionnaire. The data like demographic characteristics of informants, methods of preparation, life form, modes of application, parts used, and ethnomedicinal uses was documented. The quantitative indices including relative frequency of citation (RFC), use value (UV), informant consensus factor (ICF), fidelity level (FL), consensus value for plant part (CPP), rank order priority (ROP), percentage respondent knowledge (PRK), were applied to analyze the collected data. Furthermore, primary data were also compared with fifteen papers published from adjoining areas by Jaccard index (JI). Results: The current study reported 135 medicinally important plants species belonging to 115 genera and 54 families. The dominating family was Asteraceae (14 sp.), followed by Fabaceae (11 sp.), Rosaceae (11 sp.), Lamiaceae (8 sp.), Moraceae (5 sp.), Solanaceae, Cyperaceae, Euphorbiaceae (4 sp.) and Poaceae, Sapindaceae, Rhamnaceae, Mrytaceae, Malvaceae (3 sp.) for each. The study revealed that there were small differences in usage of medicinal plants of different families. The herbaceous life form was dominating the study area with (79 sp.) used as herbal medicines followed by shrubs (23 sp.) and trees (33 sp.). The comparative study of for novelty of species and their uses by JI revealed 13 novel plants species which were not reported earlier from this region. Conclusions: Local inhabitants still prioritize herbal medicines as an effective way to treat a wide variety of ailments. Elders and health practitioners of the study area are well aware of indigenous knowledge about medicinal plants, but young people are not much interested in herbal practices. Thus, valuable knowledge about the use of plants is on the verge of decline. The overexploitation and seasonal fires are major threats for medicinal flora in the area.

• Nanomaterials
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• v.12 no.24
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• pp.4392-4416
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• 2022

Premature drug release and poor controllability is a challenge in the practical application of tumor therapy, which may lead to poor chemotherapy efficacy and severe adverse effects. In this study, a reactive oxygen species (ROS)-cleavable nanoparticle system (MXene-TK-DOX@PDA) was designed for effective chemotherapy drug delivery and antibacterial applications. Doxorubicin (DOX) was conjugated to the surface of (3-aminopropyl)triethoxysilane (APTES)-functionalized MXene via an ROS-cleavable diacetoxyl thioketal (TK) linkage. Subsequently, the surfaces of the MXene nanosheets were coated with pH-responsive polydopamine (PDA) as a gatekeeper. PDA endowed the MXene-TK-DOX@PDA nanoparticles with superior biocompatibility and stability. The MXene-TK-DOX@PDA nanoparticles had an ultrathin planar structure and a small lateral size of approximately 180 nm. The as-synthesized nanoparticles demonstrated outstanding photothermal conversion efficiency, superior photothermal stability, and a remarkable extinction coefficient (23.3 L g^-1 cm^-1 at 808 nm). DOX exhibited both efficient ROS-responsive and pH-responsive release performance from MXene-TK-DOX@PDA nanoparticles due to the cleavage of the thioketal linker. In addition, MXene-TK-DOX@PDA nanoparticles displayed high antibacterial activity against both Gram-negative Escherichia coli (E. coli) and Gram-positive Bacillus subtilis (B. subtilis) within 5 h. Taken together, we hope that MXene-TK-DOX@PDA nanoparticles will enrich the drug delivery system and significantly expand their applications in the biomedical field

• Radiation Oncology Journal
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• v.21 no.4
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• pp.253-260
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• 2003

Purpose: No general consensus has been reached regarding the necessity of postoperative radiation therapy (PORT) and the optimal techniques of its application for patients with chest wall invasion (pT3cw) and node negative (NO) non-small cell lung cancer (NSCLC). We retrospectively analyzed the PT3cwN0 NSCLC patients who received PORT because of presumed inadequate resection margin on surgical findings. Materials and Methods: From Aug. 1994 till June 2000, 21 pT3cwN0 NSCLC patients received PORT at Samsung Medical Center; all of whom underwent curative on-bloc resection of the primary tumor plus the chest wall and regional lymph node dissection. PORT was typically stalled 3 to 4 weeks after operation using 6 or 10 MV X-rays from a linear accelerator. The radiation target volume was confined to the tumor bed plus the immediate adjacent tissue, and no regional lymphatics were included. The planned radiation dose was 54 Gy by conventional fractionation schedule. The survival rates were calculated and the failure patterns analyzed. Results: Overall survival, disease-free survival, loco-regional recurrence-free survival, and distant metastases-free survival rates at 5 years were 38.8$\%$, 45.5$\%$, 90.2$\%$, and 48.1$\%$, respectively. Eleven patients experienced treatment failure: six with distant metastases, three with intra-thoracic failures, and two with combined distant and intra-thoracic failures. Among the five patients with intra-thoracic failures, two had pleural seeding, two had in-field local failures, and only one had regional lymphatic failure in the mediastinum. No patients suffered from acute and late radiation side effects of RTOG grade 3 or higher. Conclusion: The strategy of adding PORT to surgery to improve the probability, not only of local control but also of survival, was justified, considering that local control was the most important component in the successful treatment of pT3cw NSCLC patients, especially when the resection margin was not adequate. The incidence and the severity of the acute and late side effects of PORT were markedly reduced, which contributed to improving the patients' qualify of life both during and after PORT, without increasing the risk of regional failures by eliminating the regional lymphatics from the radiation target volume.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.3
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• pp.317-324
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• 2007

Fluorescence measurements of dissolved organic matter(DOM) have the superior advantages over other analysis tools for applying to water quality management. A preliminary study was conducted to test the feasibility of applying synchronous fluorescence measurements for tracing and monitoring pollution sources in a small stream located in an upstream area of the Sooyoung watershed in Busan. The water quality of the small stream is affected by leachate from sawdust pile and discharge of untreated sewage. The sampling sites included an upstream site, two pipes discharging untreated sewage, leachate from sawdust, and a downstream site. Of the five field samples, the leachate was distinguished from the other samples by a high peak at a lower wavelength range and a blunt peak at 350nm, suggesting that synchronous fluorescence can be used as a discrimination tool for monitoring the pollution. The efficacy of various indices derived from the spectral features to discriminate the pollution source was tested for well-defined mixture of the sawdust leachate and the upstream stream by comparing (1)the difference between measured values and those predicted based on mass balance and the characteristics of the two samples and (2)the linear correlations between index values and mass ratios of the sample mixtures. Of various discrimination indices selected, fluorescence intensities at 276 nm$({\Delta}\lambda=30nm)$and 347 nm$({\Delta}\lambda=60nm)$ were suggested as promising potential discrimination indices for the sawdust pollution source. Despite the limited number of samples and the study area, this study illustrates the evaluation process that should be followed to develop rapid, low-cost discrimination indices to monitor pollution sources based on end member mixing analyses.

• Current Research on Agriculture and Life Sciences
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• v.9
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• pp.1-9
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• 1991

Bulbs of two introduced garlic cultivars, Sanghae-joseng and Spain strain, were purchased in a market and anatomical characteristics of them were investigated according to the weight of individual bulbs. The materials used were planted and grown in the field. Bulbs harvested were classified according to weight and their anatomical characteristics were recorded. 1. In both cultivars the larger the bulb, the more flat the bulb shape. 2. The bigger the bulbs were, the larger the number of cloves per bulb was, Spain strain had more cloves per bulb than Sanghae-joseng in the same size bulbs. 3. In Sanghae-joseng, more cloves were formed in outer layer than in inner layer in the bulbs produced in 1990. But more cloves were formed in inner layer in the bulbs of 35 g or smaller produced in 1991. In Spain strain, more cloves were formed in inner layer in the bulbs of 40 g or more produced in 1990. But more cloves were formed in outer layer in the bulbs produced in 1991 regardless of bulb size. In both cultivars, the number of primary cloves and total number of cloves was very small in both cultivars, but it was a little bigger in Sanghae-joseng than in spain strain. 5. In the bulbs produced in both 1990 and 1991 of Spain strain and in bulbs produced in 1990 of Sanghae-joseng weight of cloves in outer layer was significantly heavier than that in outer layer, the trend was not conspicuous in 1991 produce of Sanghae-joseng. 6. In both cultivars clove size range was narrow in small bulbs and wide in large bulbs. In distribution of cloves in size, medium ones were most frequent, and the frequency of large cloves increased with increased size of bulbs. Sanghae-joseng produced larger cloves than Spain strain in the same size cloves.