• The Korean Journal of Food And Nutrition
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• v.36 no.6
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• pp.543-550
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• 2023

Mulberry fruit is a superior source of polyphenols, especially anthocyanin, and has a long history of use as an edible fruit and traditional medicine. The anthocyanin composition of mulberry fruit from 15 Korean cultivars was analyzed by ultra-performance liquid chromatography diode array detector with quadrupole time of flight/mass spectrometry (UPLC-DAD-QToF/MS) based on a cyanin internal standard. The four glycosides were identified by comparison with authentic standards and published reports. The major anthocyanin was cyanidin 3-O-glucoside (71.7%), followed by cyanidin 3-O-rutinoside (26.6%). The minor components (total of 1.7%) were pelargonidin 3-O-glucoside and pelargonidin 3-O-rutinoside. The total anthocyanin content (mg/100 g, dry weight) of mulberry fruit varied by cultivar and ranged from 471.5±4.0 (Su Hong) to 4,700.2±54.0 (Gwa Sang2). Among the 15 cultivars examined, Gwa Sang2 showed the highest level of cyanidin 3-O-glucoside (3,133.4±32.6), which was 9-fold higher than that of Su Hong (351.5±3.4). In conclusion, anthocyanin profiles, including pelargonidin 3-O-glucoside and pelargonidin 3-O-rutinoside, were reported for the first time from 15 Korean mulberry fruit cultivars. The results will contribute valuable information on pharmaceutical properties, breeding superior mulberry cultivars, and food industries.

• Journal of the Korea Institute of Building Construction
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• v.24 no.3
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• pp.319-329
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• 2024

This study examined domestic and international regulations concerning concrete unit weight, along with an evaluation of unit weight in concrete poured on construction sites. Fluctuations in unit weight were observed to correlate with concrete quality issues such as material separation, bleeding, and latency. A word cloud analysis, centered on the concept of concrete quality, further highlighted the significant influence of unit weight. Comparative analysis between Korea and Japan revealed few substantial differences in unit weight management and measurement techniques. However, calculation of concrete unit weight at delivery, using the unit volume mass method, indicated considerable variability among random on-site samples. Notably, the unit weight often exceeded the recommended standard. These findings emphasize the necessity for strict adherence to unit weight standards by all stakeholders involved in concrete production and construction, including ready-mix concrete (REMICON) producers, construction firms, and inspectors. To ensure consistent quality of cast concrete on-site, the establishment of a more comprehensive and practical system is recommended, incorporating measures such as on-site inspections.

• Journal of Korean Home Economics Education Association
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• v.19 no.2
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• pp.61-75
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• 2007

The method used in this descriptive study is the survey. The purpose of the study is to investigate performances of middle school home economics(HE) teachers regarding the HE subject. Respondents in this study were 177 HE teachers. Questionnaires from HE teachers were collected through e-mails. With the operation of the SPSS/Win (ver10.1) program, the analyses such as mean, standard deviation, frequencies, percents, t-test and ANOVA are done to see the relations between the related variables. The results of this study were as follows. First, the middle school HE teachers performed well above the standards in terms of planning, execution, and evaluation about self supervision related to HE. Second, the HE teachers collected materials for instruction by using literary (books) survey, Internet and mass media. They mainly focused on improving ways of "teaching and learning" and deepening the studies related to contents of textbooks. Third, the HE teachers used various ways to improve self supervision in the following order: mass media, literary (books) survey, participation in societies for researches, meetings, various training and field trip More than half of the middle school HE teachers proceeded to graduate schools, joined meetings for researches and had experiences of taking classes in private institutes. They also made a field trip once or twice a year and depended much on TV programs and education broadcasting programs as ways of improving their performances related to self supervision. While they were actively sharing information with their peer group, they made little effort at analyzing and evaluating their classes and utilizing expert group for their classes. The main problems as to self supervision were that only the half of the HE teachers responded that they were performing self supervision related to their classes well above the standards and the area where they heavily focused on has been "teaching and learning" and "the studies related to contents of textbooks". Therefore, to motivate incentives of the HE teachers for self supervision, meetings for researches should be activated and various training programs should be developed. In addition, government should give administrative and institutional support through a publication of books introducing detailed ways of self supervision and an establishment of centers and institutions for supporting self supervision.

• The Journal of the Petrological Society of Korea
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• v.20 no.3
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• pp.161-172
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• 2011

Open beaker digestion method is routinely used as the sample preparation technique for trace element determination of rock samples by inductively coupled plasma mass spectrometry, With this method, however, dissolution of Zr and Hf is not always guaranteed especially when the samples contain refractory minerals. In this study, glass bead digestion technique was compared with conventional open beaker digestion technique for the sample preparation of three USGS rock standards such as AGV-2, BHVO-2, and G-3. Thirty trace elements including rare earth elements were analysed by ICP-MS and ICP-AES. There were no clear differences in analytical results for the AGV-2 and BHVO-2 standards between the two techniques, but Zr, Hf, Y, and middle- to heavy- rare earth element concentrations of the G-3 standard prepared by open beaker digestion technique were significantly lower than the recommended values. This can be attributed to the presence of refractory mineral zircon. On the contrary, all the analytical results of the G-3 standard prepared by glass bead digestion technique were in good agreement with the recommended values, indicating complete dissolution of zircon. The analytical results show that the volatile elements such as Pb and Zn were not lost during the preparation of glass bead. Low dilution glass bead digestion technique described here will be very helpful to enhance precision and accuracy of trace element analysis for geological samples containing refractory minerals.

• Journal of Food Hygiene and Safety
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• v.38 no.2
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• pp.37-45
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• 2023

The surge in food delivery systems during the coronavirus 2019 pandemic necessitated this study of heavy metal migration from food contact materials (FCMs). A total of 104 samples of FCMs, comprising 51 polypropylene (PP), 21 polyethylene (PE), and 32 polystyrene (PS) samples of six different types of FCMs (containers, covers, table utensils, cups, pouches, and wrappers) used for food delivery distributed in Korea, were collected and investigated for migration of three heavy metals (Pb, Cd, and As) using inductively coupled plasma-mass spectrometry (ICP-MS) to determine whether they complied with Korea's Standards and Specifications for Utensils, Containers, and Packages. Acetic acid (4%, v/v) was used as the food simulant, and tests were performed at 100℃ (in harsh conditions) for 30 min. Linearity of Pb, Cd, and As showed acceptable results with a coefficient of determination (R²) value of 0.9999. Limit of detection (LOD) and limit of quantification (LOQ) of Pb, Cd, and As were 0.001, 0.001, and 0.001 ㎍/L and 0.002, 0.003, and 0.003 ㎍/L, respectively. Accuracy and precision results complied with the criteria presented in the European Commission Joint Research Centre guidelines. The average concentration of Pb, Cd, and As migration detected in a total of 104 samples was 0.009-0.260 ㎍/L, which was very low compared with the migration specification set in the Standards and Specifications for Utensils, Containers, and Packages. The maximum level of Pb corresponded to 0.23% of the migration limit. There were no samples exceeding the limit. Thus, this study confirmed that the heavy metal contents of FCMs used for delivery food distributed in Korea were safely managed. The data from this study represent an invaluable source for science-based safety management of hazardous heavy metals migrating from FCMs used in the food delivery industry.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.479-495
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• 2018

This study was carried out to research the multimedia fate modeling, concentration distribution and impact assessment of polycyclic aromatic hydrocarbons (PAHs) emitted from automobiles, which are known as carcinogenic and mutation chemicals. The amount of emissions of PAHs was determined based on the census data of automobiles at a target S-city and emission factors of PAHs, where multimedia fugacity modeling was conducted by the restriction of PAHs transfer between air-soil at the impervious area. PAHs' Concentrations and their distributions at several environmental media were predicted by multimedia fugacity model (level III). The residual amounts and the distributions of PAHs through mass transfer of PAHs between environment media were used to assess the health risk of PAHs at unsteady state (level IV), where the sensitivity analyses of the model parameter of each variable were conducted based on Monte Carlo simulation. The experimental result at S-city showed that Fluoranthene among PAHs substances are the highest residual concentrations (60%, 53%, 32% and 34%) at all mediums (atmospheric, water, soil, sediment), respectively, where most of the PAHs were highly accumulated in the sediment media (more than 80%). A result of PAHs concentration changes in S-city over the past 34 years identified that PAHs emissions from all environmental media increased from 1983 to 2005 and decreased until 2016, where the emission of heavy-duty vehicle including truck revealed the largest contribution to the automotive emissions of PAHs at all environment media. The PAHs concentrations in soil and water for the last 34 years showed the less value than the legal standards of PAHs, but the PAHs in air exceeded the air quality standards from 1996 to 2016. The result of this study is expected to contribute the effective management and monitoring of toxic chemicals of PAHs at various environment media of Metropolitan city.

• Journal of Korean Elementary Science Education
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• v.42 no.4
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• pp.523-537
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• 2023

This study encompassed the responses of 284 elementary school teachers, focusing on their teaching experiences, readiness, and needs for science education concerning the risk posed by science and technology. The key findings are summarized as follows. First, a significant portion of teachers lacked prior experience in addressing risks associated with science and technology within their science education practices. Second, a greater number of teachers were aware of the inclusion of risk-related content in the 2022 revised science curriculum's achievement standards than those who were not. Third, in terms of teachers' understanding of risk perception, risk assessment, and risk management, they demonstrated a relatively high level of understanding of risk perception but a lower level of understanding of risk assessment. Fourth, most teachers had not undergone any formal education or training related to risk. Fifth, among the 10 objectives of risk education, teachers displayed the highest competence in teaching "information use" and "action skills," while their lowest competence was observed in "interpreting probabilities" and "evaluating risk assessment." Sixth, a majority of teachers believe that it is important to teach about the risks posed by science and technology in school science classes, with "action skills," "information use," and "decision-making skills" being considered the most important and "action skills," "information use," and "influence of mass media" being regarded as the most urgent. However, teachers anticipated difficulties in addressing risk in school science classes, including a lack of relevant educational materials, a lack of understanding of teaching theories related to risk education, and the relationship between science curriculum content and achievement standards. Seventh, as a result of calculating the educational needs for each of the 10 goals of risk education, "influence of risk perception," "decision-making skills," "action skills," and "evaluate risk assessment" were the priority needs of elementary school teachers.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.E
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• pp.1-17
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• 2000

In this study, the concentrations of particulate organic constituents of environmental tobacco smoke(ETS) were determined using an environmental smog chamber, where ETS is the sole source of target compounds. ETS was generated in a 30 ㎥ environmental chamber by a number of different cigarettes, including the Kentucky 1R4F reference cigarette and eight commercial brands. A total of 12 experimental runs was conducted, and target analytes included a group of ETS markers both in vapor and particulate phase and a class of polycylic aromatic hydrocarbos(PAHs) associated with ETS particles. The mass concentrations of PAH in ETS particles were also determined. The average contents of benzo(a) pyrene and benzo(a) anthracene in ETS particles for the commercial brands were 12.8 and 21.5$\mu\textrm{g}$/g, respectively, There values are all somewhat higher than those determined previously by other studies. Results form the chamber study are further used to estimate the average and variability of cigarette yields for target compounds associated with ETS. Finally, ratios of RSP to the surrogate standards of UVPM, FPM and solanesol were calculated for each sample. The average conversion factors factors for the eight commercial brands were 7.3, 38, and 41 for UVPM, EPM, and solanesol, respectively. The UVPM and FPM factors are in good agreement with the recently published values. Whereas there might be a substantial difference in the solanesol content among cigarettes produced in different countries, the variability is somewhat greater than those of UVPM and FPM, Unfortunately, comparison of the PAH yield data from this study with literature values was complicated by a lack of consistency in cigarette smoke generating methodology. Validation of the PAH yields was also difficult due to a lack of information on the ETS related PAH in the literature. From and engineering viewpoint , however, these data on the cigarette yields of ETS components may still provide useful information to studies on the mathematical modeling of indoor air quality management regarding tobacco smoke as a source of interest, or to studies on the assessment of human exposure to ETS.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.5
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• pp.31-41
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• 2009

Under the Korea Building Act, anyone planning to build a building or buildings on a site over $200m^2$ must plant plants over a specific area. In large scale development this rule is adhered to well, but such is not the case in small scale development. Therefore, special attention must be given to small scale development. Thus, the purpose of this research is to analyze the current situation and practice of planting at small scale development sites in Seoul, and then suggest policies for improving them. In this study using the data covering Seongbuk-Gu and Gangnam-Gu, which was surveyed in 2002, the current situation and practice of planting at small scale development sites was analyzed. After a questionnaire survey was conducted with government officers and building owners, the same analysis was made. Then the policies for improvement were extracted. The results are as follows: 1. In superordinate planning stage, because the minimum standards are too low, those must be strengthened. Any district plan does not control planting in private building lots. This requests active application of planting in private building lots as a design control measure in district planning. 2. In the building design stage, there are no guidelines. The obligation of building set-back between adjacent buildings by the Korean Building Act produces mass shaded and inferior planting beds. The act also is blocking landscape architects' participation in small scale development. And wall installations deteriorate the streetscape and growth of plants with shading. Therefore guidelines must be made. 3. In each stage of the building permit, the permit for building completion, and maintenance the Korean Building Act is blocking landscape architects' participation in small scale development, so the planting plan is completely handled by nonprofessional persons. Therefore, the act should be amended in order to make way for landscape architects' participation in each stage of the small scale development process.

• Journal of Environmental Health Sciences
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• v.38 no.3
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• pp.233-240
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• 2012

Objectives: The changes in atmospheric $PM_{2.5}$ concentrations were extensively studied in one metropolitan city (Incheon), two small and medium sized cities (Gunsan, Cheonan), and a rural area (Gosan in Jeju). The concentrations of heavy metals (Cr, Mn, Fe, Ni, Cu, Zn, Al, Pb) and the component features of $PM_{2.5}$ were determined for these areas. Methods: This study sampled $PM_{2.5}$ at the designated locations in the metropolitan (Incheon), small and medium sized cities (Gunsan in Jeonbuk and Cheonan in Chungnam), and rural area (Gosan in Jeju) to investigate concentrations with a sampling device (Sequential sampler, APM Eng., Korea). Sampling was undertaken over months, from June 26 to November 26, 2009. Sampling was conducted a total of 44 times, with routine sampling at intervals of six days (24 total times) and intensive sampling (20 total times) during the summer and fall. Mass concentration of $PM_{2.5}$ was evaluated and the concentrations of heavy metals (Cr, Mn, Fe, Ni, Cu, Zn, Al, Pb) were analyzed. Results: The geometric average of concentrations of $PM_{2.5}$ per district was $35.289{\mu}g/m^3$ for Cheonan, $29.955{\mu}g/m^3$ for Incheon, $24.119{\mu}g/m^3$ for Gunsan, and $18.773{\mu}g/m^3$ for Jeju, respectively. The average concentration of $PM_{2.5}$ in Cheonan was the highest. The seasonal concentration distributions per district showed Cheonan $33.387{\mu}g/m^3$, Incheon at $31.550{\mu}g/m^3$, Gunsan $22.900{\mu}g/m^3$, and Jeju $18.900{\mu}g/m^3$ in the summer. For the autumn, the concentrations were $36.873{\mu}g/m^3$ in Cheonan, $28.625{\mu}g/m^3$ in Incheon, $25.227{\mu}g/m^3$ in Gunsan, and $18.667{\mu}g/m^3$ in Jeju. According to the collected data, the concentration showed a tendency to rise during the autumn in all of these regions with the exception of Incheon. For heavy metal distribution per district, Fe showed an elevated concentration during the summer while high concentrations of Pb and Zn occurred during the autumn. Conclusion: These results demonstrated that atmospheric factors affected the concentrations of heavy metals. The results of this study could be used as foundational data for setting environmental air standards focusing on a $PM_{2.5}$ receptor.