• Clean Technology
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• v.28 no.1
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• pp.38-45
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• 2022

CuCl₂-loaded V₂O₅-WO₃/TiO₂ catalyst showed excellent activity in the catalytic oxidation of elemental mercury to oxidized mercury even under SCR condition in the presence of NH₃, which is well known to significantly inhibit the oxidation activity of elemental mercury by HCl. Moreover, it was confirmed that, when SO₂ was present in the reaction gas together with HCl, excellent elemental mercury oxidation activity was maintained even though CuCl₂ supported on the catalyst surface was converted to CuSO₄. This is thought to be because not only HCl but also the SO₄ component generated on the catalyst surface promotes the oxidation of elemental mercury. However, in the presence of SO₂, the total mercury balance before and after the catalytic reaction was not matched, especially as the concentration of SO₂ increased. In order to understand the cause of this, further studies are needed to investigate the effect of SO₂ in the SnCl₂ aqueous solution employed for mercury species analysis and the effect of sulfate ions generated on elemental mercury oxidation. It was confirmed that SO₂ also promotes NO_x removal activity, which is thought to be because the increase in acid sites by SO₄ generated on the catalyst surface by SO₂ facilitates NH₃ adsorption. The composition change and structure of the components present on the catalyst surface under various reaction conditions were measured by XRD and XRF. These measurement results were presented as a rational explanation for the results that SO₂ enhances the oxidation activity of elemental mercury and the NO_x removal activity in this catalyst system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.1092-1099
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• 2022

Research on exhaust aftertreatment devices to reduce air pollutants and greenhouse gas emissions is being actively conducted. However, in the case of the particulate matters/nitrogen oxides (PM/NOx) simultaneous reduction device for ships, the problem of back pressure on the diesel engine and replacement of the filter carrier is occurring. In this study, for the optimal design of the integrated device that can simultaneously reduce PM/NOx, an appropriate standard was presented by studying the flow inside the device and change in back pressure through the inlet/outlet pressure. Ansys Fluent was used to apply porous media conditions to a diesel particulate filter (DPF) and selective catalytic reduction (SCR) by setting porosity to 30%, 40%, 50%, 60%, and 70%. In addition, the ef ect on back pressure was analyzed by applying the inlet velocity according to the engine load to 7.4 m/s, 10.3 m/s, 13.1 m/s, and 26.2 m/s as boundary conditions. As a result of a computational fluid dynamics analysis, the rate of change for back pressure by changing the inlet velocity was greater than when inlet temperature was changed, and the maximum rate of change was 27.4 mbar. This was evaluated as a suitable device for ships of 1800kW because the back pressure in all boundary conditions did not exceed the classification standard of 68mbar.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.9 no.1
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• pp.9-16
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• 2023

Liposomes as drug delivery system have proved useful carrier for various disease, including cancer. In addition, perfluorocarbon cored microbubbles are utilized in conjunction with high-intensity focused-ultrasound (HIFU) to enable simultaneous diagnosis and treatment. However, microbubbles generally exhibit lower drug loading efficiency, so the need for the development of a novel liposome-based drug delivery material that can efficiently load and deliver drugs to targeted areas via HIFU. This study aims to develop a liposome-based drug delivery material by introducing a substance that can burst liposomes using ultrasound energy and confirm the ability to target tumors using PET imaging. Liposomes (Lipo-DOX, Lipo-DOX-Au, Lipo-DOX-Au-RGD) were synthesized with gold nanoparticles using an avidin-biotin bond, and doxorubicin was mounted inside by pH gradient method. The size distribution was measured by DLS, and encapsulation efficiency of doxorubicin was analyzed by UV-vis spectrometer. The target specificity and cytotoxicity of liposomes were assessed in vitro by glioblastoma U87mg cells to HIFU treatment and analyzed using CCK-8 assay, and fluorescence microscopy at 6-hour intervals for up to 24 hours. For the in vivo study, U87mg model mouse were injected intravenously with 1.48 MBq of ⁶⁴Cu-labeled Lipo-DOX-Au and Lipo-DOX-Au-RGD, and PET images were taken at 0, 2, 4, 8, and 24 hours. As a result, the size of liposomes was 108.3 ± 5.0 nm at Lipo-DOX-Au and 94.1 ± 12.2 nm at Lipo-DOX-Au-RGD, and it was observed that doxorubicin was mounted inside the liposome up to 52%. After 6 hours of HIFU treatment, the viability of U87mg cells treated with Lipo-DOX-Au decreased by around 20% compared to Lipo-DOX, and Lipo-DOX-Au-RGD had a higher uptake rate than Lipo-DOX. In vivo study using PET images, it was confirmed that ⁶⁴Cu-Lipo-DOX-Au-RGD was taken up into the tumor immediately after injection and maintained for up to 4 hours. In this study, drugs released from liposomes-gold nanoparticles via ultrasound and RGD targeting were confirmed by non-invasive imaging. In cell-level experiments, HIFU treatment of gold nanoparticle-coupled liposomes significantly decreased tumor survival, while RGD-liposomes exhibited high tumor targeting and rapid release in vivo imaging. It is expected that the combination of these models with ultrasound is served as an effective drug delivery material with therapeutic outcomes.

• Korea Trade Review
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• v.42 no.6
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• pp.111-129
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• 2017

According to the World Bank statistics, China's contribution to global economic growth during the year of 2013-2016 was estimated at 31.6 percent. This figure is even larger than 29.0 percent, the contribution by summing each contribution of the United States, EU and Japan. The Chinese commodity trade accounts for up to 11.5 percent of world trade volume. Thus, we can consider that the Chinese economy has a strong influence on the global economy. The primary purpose of this study is to analyze the contribution level of Chinese seaborne trade volume on world economy. First, this study conducted a time-lag analysis using Moran test, so we can find that China's level of contribution to global economic growth varies from time to time. The contribution of the first phase (1999-2007) was nearly three times higher than the contributions from the second phase (2008-2016), suggesting that the overall contraction of the global trade volume starting from the subprime mortgage crisis in 2008 has continued until recently and recovery has not even occurred. Second, using the econometrics model, this study conducted an regression analysis of the impact of Chinese imports and exports in chemicals, grain, steel, crude oil, and container on global economic growth. Fixed effects model with time series data has been applied to examine the effect of Chinese seaborne trade volume on global economic growth. According to the empirical analysis of this study, China's exports of steel products, exports of container, imports of containers, imports of crude oil and imports of grain have significant contributions to global economic growth. Estimates of China's exports of steel products, exports of container, imports of containers, imports of crude oil and imports of grain are 1.023, 1.020, 1.019, 1.007 and 1.006, respectively. For example, the estimated value 1.023 of China's exports of steel products means that the growth rate can be 1.023 times higher than the current world GDP growth rate if Chinese seaborne trade volume of exports of steel products increased by one unit (one million tons). This study concludes that the expansion of China's imports and exports should be realized first to increase the global GDP growth rate. The expansion of Chinese trade can lead to a simultaneous stimulus of production and consumption in China, which can even lead to global economic growth ultimately. Thus, depending on how much China's trade will be broaden in the future, the width of global economic growth can be determined.

• Analytical Science and Technology
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• v.20 no.4
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• pp.308-314
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• 2007

The analytical method of HPLC with the radial-flow electrochemical cell (RFEC) has been developed to determine doxorubicin, epirubicin, nogalamycin, daunorubicin and idarubicin simultaneously by employing a reversed-phase chromatography. Anthracyclines were detected at -0.74 V vs. a Ag/AgCl (0.01 M NaCl) reference electrode, a potential of diffusion current plateau in the mobile phase. At a $V_f$ of 1.0 mL/min doxorubicin, epirubicin, daunorubicin and idarubicin appeared at a retention time ($t_r$) of 6.4 min, 7.4 min, 12.7 min and 18.4 min, respectively, while at a $V_f$ of 0.6 mL/min, doxorubicin, epirubicin, nogalamycin, daunorubicin and idarubicin appeared at a $t_r$ of 9.9 min, 11.5 min, 13.5 min, 19.6 min and 28.7 min, respectively. The linearity between each anthracycline injected ($2.40{\times}10^{-7}M{\sim}1.42{\times}10^{-5}M$) and peak area (charge) was excellent with the square of the correlation coefficient ($R^2$) higher than 0.999. The detection limits were $1.0{\times}10^{-8}M{\sim}1.5{\times}10^{-7}M$ for the five anthracyclines. Within-day precision for the five anthracyclines were in reasonable relative standard deviations less than 3 % ($1.00{\times}10^{-6}M{\sim}1.42{\times}10^{-5}M$) except the lower concentrations less than $0.7{\mu}M$. Solid phase extractions of $1.00{\times}10^{-5}M$ epirubicin, $0.48{\times}10^{-5}M$ nogalamycin and $1.52{\times}10^{-5}M$ daunorubicin from human serum with a $C_{18}$ cartridge resulted in 97 %, 100 % and 90 % of recoveries, respectively.

• Korean small business review
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• v.39 no.1
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• pp.1-39
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• 2017

The first generation of the business that had been founded in 1960~1970s faces the situation to consider the succession of the family business developed by devotion of their whole lives in the critical timing to the next generation. In the process of selecting the party of family business succession, it is required to consider a variety of succession types including smooth transfer to the other family member or the employee of the company, selling the company, or hiring external specialist. Foreign countries acknowledge the importance of the succession in the family owned company to perform multiple studies on the influential factors to the succession, distinction, and types of family business succession; and they utilize the results for the related policy development and the support of family owned business succession. However, few studies have been conducted on the succession of the domestic family owned business and majority of them are related to the types of succession. Considering its share and influential power in the domestic economy, it is necessary to develop the guideline and the policies to solve many issues on the succession of the family owned business by systemic studies. Hence, the impact of the main characteristics in the family owned business on the types of its succession was analyzed in this study focusing on five domains of Socioemtional Wealth (SEW) in view of Behavioral Agency Theory by Gomez-Mejia et al. (2007) using the data from 540 family owned small-to-medium sized businesses so as to analyze the issues on their business succession. Upon the empirical analysis results, it was confirmed that they were influenced to the selection of succession type by family succession > internal employee succession > external succession, for the variables of social contribution which were non-financial characteristics, internal employee succession > family succession > external succession for the intellectual properties, and family succession > external succession for the management participation of the family. The distinction of social contribution were influenced the most to the selection of the succession types. Financial factors, business performance, and R&D investment variables were not significantly influenced to their selection of the succession types. In case of simultaneous management, the family succession rate was high and it showed the control effect to strengthen selecting family owned business with R&D investment, social contribution, and company history variables. The behavioral agency theory used in this study was confirmed with high explanation power on the family owned business succession. The family owned business showed the tendency to maintain SEW, and non-financial factors such as accumulated know-how and social contribution based on the long term history were significantly affected to the succession in the small-to-medium sized family owned businesses, unlike general large sized listed companies. The results of this study are expected to be helpful practically for the succession of the family owned business and to suggest the guideline for the development of governmental policy.

• Analytical Science and Technology
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• v.36 no.6
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• pp.300-314
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• 2023

The quality of the products was investigated by analyzing fluorine content, pH, preservatives and tar colors in 31 dentifrice products (6 items for children) and 15 mouthwash products (2 items for children) marketed. It was intended to provide correct information to consumers by checking whether the standards and product indications match. As a result of measuring the fluoride concentration, 26 dentifrice and 15 mouthwash products contained from 48 to 1,472 ppm and from 85 to 225 ppm, respectively. Fluorine detection rates of dentifrice and mouthwash products were 83.9 and 83.3 %, respectively showing similar levels. Of the 41 fluoride-detected dentifrice and mouthwash products, 40 were 90.7~109.8 % of the displayed amount and suitable for the fluorine content standard of 90.0 to 110.0 %, but one dentifrice was found to be inappropriate at 36.3 % of the content indicated on the product. The pH of the dentifrice was 5.1~9.4, and the mouthwash was 4.2~6.2, which met all standards. As a result of simultaneous analysis of the concentration of six preservatives, benzoic acid was detected the most in 15 cases with a 30.6 % detection rate, sorbic acid was detected in 9 cases (detection rate of 18.4 %), and all four types of methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, propyl p-hydroxybenzoate, butyl p-hydroxybenzoate were not detected. As a result of analyzing the concentration of 10 types of tar colors, six types including red40, yellow4, yellow5, yellow203, green3, and blue1 were detected in a total of 9 cases (2 dentifrices and 7 mouthwashes) with blue1 being the most frequently detected. Detected fluorine concentration, added preservatives and tar colors were consistent with the product markings and it was well written on product packaging. The detected preservatives and tar colors were at a safe level due to low risk compared to Acceptable Daily Intake.

• Journal of Food Hygiene and Safety
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• v.38 no.5
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• pp.361-372
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• 2023

Organotin pesticide is used as an acaricide in agriculture and may contaminate livestock products. This study aims to develop a rapid and straightforward analytical method for detecting organotin pesticides, specifically azocyclotin, cyhexatin, and fenbutatin oxide, in various livestock products, including beef, pork, chicken, egg, and milk, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The extraction process involved the use of 1% acetic acid in a mixture of acetonitrile and ethyl acetate (1:1). This was followed by the addition of anhydrous magnesium sulfate (MgSO₄) and anhydrous sodium chloride. The extracts were subsequently purified using octadecyl (C₁₈) and primary secondary amine (PSA), after which the supernatant was evaporated. Organotin pesticide recovery ranged from 75.7 to 115.3%, with a coefficient of variation (CV) below 25.3%. The results meet the criteria range of the Codex guidelines (CODEX CAC/GL 40). The analytical method in this study will be invaluable for the analysis of organotin pesticides in livestock products.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.41 no.4
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• pp.21-29
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• 2023

The Northern Song Dynasty, the heyday of cultural and artistic achievements, brought significant changes to the history of gardens in China. The developments and contemplations that had evolved during the previous Tang Dynasty became intertwined with literature, painting, and art, leading to garden being perceived as works of art. In particular, the emergence of Su Shi(蘇軾) that permeated literature and art during the Northern Song Dynasty, had an impact beyond individual garden creation, influencing the development of public gardens and the diversification of garden. His long exile periods served as an opportunity to understand and reflect the local culture and characteristics, influencing the development of the garden. This study focuses on the ideology of Su Shi(蘇軾) that managed various gardens, examining the relationship between his exlie life and ideology. To do so, the study examines the form of the literati's gardens managed by Su Shi(蘇軾), with a particular emphasis on the Baiheju(白鶴居) garden in Huizhou, revealing the following characteristics and values. First, Su Shi(蘇軾), who was proficient in the Three Houses: Confucianism, Buddhism, and Taoism, combined his philosophy and unique perspective techniques with the location and composition elements of Baiheju(白鶴居) to enjoy the landscape. Although the ancient residence has a simple form, it possesses expansiveness through the combination of internal and external views. The interior is designed to be perceived as a single space, but it allows overlapping experiences of space and simultaneous appreciation of different sceneries. On the other hand, the spatial layout incorporates a hierarchical order to establish a sense of order. Second, the garden reflects the local characteristics, featuring numerous tropical plants and presenting vibrant and contrasting colors with structures. The planting forms embrace the concept of "huosei seikou" (活色生香) to enhance the color harmoniously. Additionally, the garden incorporates the poet's spiritual world, projecting it onto the garden as a contemplative place for spiritual nourishment and exploration of the ideal realm. For the pursuit of serenity and profound contemplation, the selected plantings are simple yet distinctive, providing rhythm and depth to the garden space. Third, Baiheju(白鶴居) has undergone changes over the years, but fundamentally, the form and elements of the garden shaped by Su Shi(蘇軾)'s descendants persist, confirming its heritage value.

• Pediatric Infection and Vaccine
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• v.30 no.3
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• pp.121-128
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• 2023

Purpose: This study aimed to investigate the recent age distribution of Mycoplasma pneumoniae in patients with respiratory infections and the differences in diagnostic usefulness according to the methods used in these patients. Methods: We retrospectively reviewed the medical records of patients aged ≤18 years with respiratory infectious diseases who underwent polymerase chain reaction (PCR) or a specific immunoglobulin M (IgM) test between July 2016 and February 2019. The diagnosis of M. pneumoniae infection was confirmed by a positive result in the PCR or IgM test. Results: Of the 2,721 patients tested for M. pneumoniae, 2,197 underwent IgM, and 1,144 underwent PCR, with positivity rates of 17% and 20%, respectively. Among the 620 patients tested for both IgM and PCR tests simultaneously, 35% had M. pneumoniae infection, with 14% under 1 year old and 13% under 1-2 years old. The positive rate increased with age in both tests. Higher positive rates were observed in the IgM test before 3 years of age and in the PCR test after 3 years of age. The agreement rate between the two tests was 77.9% (Cohen's kappa 0.402). Conclusions: As age increased, the rates of M. pneumoniae infection also increased. In patients under 2 years of age, 4¬-14% of infections were confirmed depending on the method used. The moderate agreement between the PCR and IgM tests suggests that the simultaneous use of PCR and the IgM test for the early diagnosis should be approached with caution.