• Korean Chemical Engineering Research
• /
• v.61 no.2
• /
• pp.302-311
• /
• 2023

This study was conducted to evaluate the applicability of castor oil (CSO) as a natural wood preservative. CSO was treated into wood blocks prepared with domestic and imported wood species using a vacuum-pressure method, and then treatability, leachability and decay resistance of the CSO-treated wood blocks were examined. Although CSO was penetrated effectively into wood blocks of all wood species, the CSO-treatability was the highest in Western hemlock, followed by Japanese larch (LA), soft maple and Mongolian oak due to the difference of its anatomical structure. Except for LA, the more retained, the more leached during a saline water-immersing process for 48h. The use of ethanol added to reduce the viscosity of CSO affected negatively the treatability and leachability of wood blocks. Decay resistance, which was evaluated by the weight loss of wood blocks exposed against Fomitopsis palustris (FOP) and Trametes versicolor, of the CSO-treated/leached wood blocks was superior to that of control. Especially, most of wood blocks treated with preserving solution composed of only CSO (CSO-2) did not decayed and showed a very low weight loss against FOP. The decay resistance results from CSO retained in wood blocks after leaching. The retention of CSO could identify using the observation of X-ray microscope. Length of wood strips, which were treated with CSO-2 and then immersed in saline water for 2 weeks, hardly changed in all cutting directions. In addition, weight gain and length-swelling rate of the wood strips were extremely low compared to those of control. These results indicate that moisture resistance of the wood strips was improved by the CSO treatment. It is concluded that the treatment of CSO using a vacuum-pressure method provides the decay resistance and dimensional stability of wood, and thus CSO can be used as a natural wood preservative on various indoor and outdoor circumstances.

• Korean Journal of Environment and Ecology
• /
• v.36 no.6
• /
• pp.566-574
• /
• 2022

Heavy metals are one of the dangerous pollutants that threaten urban biodiversity due to their accumulation over a long period without being decomposed in vivo. Accordingly, there is a need for biological monitoring to compare accumulation concentrations in living organisms according to the degree of heavy metal exposure to evaluate heavy metal contamination in the air in urban areas. This study aims to examine the possibility of using nesting materials as heavy metal monitoring samples and determine the effects of heavy metals on Paridae. We installed 54 artificial nest boxes in the research areas that included campus green spaces (14), urban forests (11), and urban parks (29) on a university campus in Cheonan City, Chungcheongnam Province. The birds' use rate of artificial nest boxes was 11/14 (78.57%) in campus green spaces, 8/11 (72.72%) in urban forests, and 6/29 (20.68%) in urban parks. Moss materials were collected from collected nests, and the heavy metal accumulation characteristics of each type of urban green space and the effects of heavy metals on the success of fledging of Paridae were compared through heavy metal analysis. The analysis showed that the average concentrations of zinc and lead were 228.08±209.62 ㎍/dry g and 17.67 ± 6.72 ㎍/dry g, respectively. There was no significant difference in zinc concentration for each type of urban green space (Kruskal-Wallis test, p-value=0.28), but lead concentration showed a significant difference (Kruskal-Wallis test, p<0.05^*). Of the 21 Paridae, nests analyzed for heavy metals, fledging of birds was observed in 11 nests (52.38%). Fledging of birds observed in each urban green space type was 7 campus green spaces (77.78%), 6 in urban forests (85.71%), and 1 in urban park (20%), mainly in urban forests and green spaces on campus. Heavy metal concentrations were compared to check the effect of heavy metal accumulation on the successful fledging of Paridae, but there was no statistically significant difference (Zn: W=44, p-value=0.74, Pb: t=0.64676, df =7.2422, p-value=0.54). This study is a basic study using the nesting materials of Paridae as heavy metal monitoring samples, and it is determined that it can be used as basic data for non-invasive biological monitoring.

• Journal of the Korean Society of Radiology
• /
• v.17 no.3
• /
• pp.441-447
• /
• 2023

Lead(Pb), which is currently mainly used for shielding purposes in the medical radiation, has excellent radiation shielding functions, but is continuously exposed to radiation directly or indirectly due to the harmfulness of lead itself to the human body and the inconvenience caused by its heavy weight. Research on shielding materials that are human-friendly, lightweight, and convenient to use that can block risks and replace lead is continuously being conducted. In this study, based on the commonly used polyethylene terephthalate (PET) film and the fabric material used in actual radiation protective clothing, a multi-layer thin film was realized through sputtering and vacuum deposition of bismuth, tungsten, and tin, which are metal materials that can shield radiation. Thus, a shielding film was produced and its applicability as a radiation shielding material was evaluated. The radiation shielding film was manufactured by establishing the optimized conditions for each shielding material while controlling the applied voltage, roll driving speed, and gas supply amount to manufacture the shielding film. The adhesion between the parent material and the shielding metal thin film was confirmed by Cross-cut 100/100, and the stability of the thin film was confirmed through a hot water test for 1 hour to measure the change of the thin film over time. The shielding performance of the finally realized shielding film was measured by the Korea association for radiation application (KARA), and the test conditions (inverse wide beam, tube voltage 50 kV, half layer 1.828 mmAl) were set to obtain an attenuation ratio of 16.4 (initial value 0.300 mGy/s, measured value 0.018 mGy/s) and damping ratio 4.31 (initial value 0.300 mGy/s, measured value 0.069 mGy/s) were obtained. by securing process efficiency for future commercialization, light and shielding films and fabrics were used to lay the foundation for the application of films to radiation protective clothing or construction materials with shielding functions.

• Korean Journal of School Psychology
• /
• v.15 no.3
• /
• pp.459-488
• /
• 2018

The self-report assessment has been most commonly used to estimate bullying/victimization (B/V) rates in most domestic and international prevalence studies. However, the presence of many potential biasing factors in such an assessment method, including specific operationalization/measurement strategies and testing conditions, has become an issue due to a considerable variability in reported involvement rates across studies. This study analyzed self-reported B/V involvement rates on Olweus Bullying Questionnaire (OBQ) among 690 Korean middle school students by gender and two different cut-offs (generous vs. strict cut-offs) and examined if the involvement rates were significantly varied by testing conditions such as presentation vs. omission of a precise definition of B/V, anonymous vs. non-anonymous/confidential administration, and the use of global vs. specific questions. Chi-square analyses revealed that boys displayed higher involvement rates on global measures of B/V and on items related to direct forms of B/V, with no significant gender differences on specific measures of relational B/V rates. It was also found that a global rate of bullying and specific rates of verbal B/V were 111% to 157% higher when no definition was provided. However, anonymous vs. non-anonymous administration had no significant impacts on rates of involvement, except for one item; there were also no significant differences in reported degrees of frankness and perceived confidentiality of their responses across two adminstration conditions. Finally, when involvement rates were assessed by using specific vs. global items, they were 68% to 148% higher with binominal correlations in low to moderate ranges. Findings also indicated that global items had a high specificity but a relatively low sensitivity. Implications of these findings were fully discussed for researchers and practitioners in the field of B/V assessment.

• Journal of Food Hygiene and Safety
• /
• v.38 no.6
• /
• pp.430-441
• /
• 2023

Velvet antler is widely used as a traditional medicine, and numerous studies have demonstrated its tremendous nutritional and medicinal values including immunity-enhancing effects. This study aimed to investigate different deer velvet extracts (Sample 1: raw extract, Sample 2: dried extract, and Sample 3: freeze-dried extract) for proximate composition, uronic acid, sulfated glycosaminoglycan, sialic acid, collagen levels, and chemical components using ultra-performance liquid chromatography-quadrupole-time-of-light mass spectrometry. In addition, we evaluated the cytotoxic effect of the deer velvet extracts on BV2 microglia, HT22 hippocampal cells, HaCaT keratinocytes, and RAW264.7 macrophages using the cell viability MTT assay. Furthermore, we evaluated acute toxicity of the deer velvet extracts at different doses (0, 500, 1000, and 2000 mg/kg) administered orally to both male and female ICR mice for 14 d (five mice per group). After treatment, we evaluated general toxicity, survival rate, body weight changes, mortality, clinical signs, and necropsy findings in the experimental mice based on OECD guidelines. The results suggested that in vitro treatment with the evaluated extracts had no cytotoxic effect in HaCaT keratinocytes cells, whereas Sample-2 had a cytotoxic effect at 500 and 1000 ㎍/mL on HT22 hippocampal cells and RAW264.7 macrophages. Sample 3 was also cytotoxic at concentrations of 500 and 1000 ㎍/mL to RAW264.7 and BV2 microglial cells. However, the mice treated in vivo with the velvet extracts at doses of 500-2000 mg/kg BW showed no clinical signs, mortality, or necropsy findings, indicating that the LD50 is higher than this dosage. These findings indicate that there were no toxicological abnormalities connected with the deer velvet extract treatment in mice. However, further human and animal studies are needed before sufficient safety information is available to justify its use in humans.

• Journal of the Society of Disaster Information
• /
• v.19 no.4
• /
• pp.869-881
• /
• 2023

Purpose: This study aims to come up with improvement measures to improve the effectiveness of child safety measures. Method: The current status of child safety accidents was investigated and implications were deduced by analyzing major child safety measures by government department in the past. In addition, a perception survey was conducted on 1,000 people including children, guardians, and children's facility workers who are subject to child safety policies. Result: Regarding the safety of children's living space(environment), 35.3% of guardians answered that more than 1/3 of them were not safe. Both guardians(95.3%) and children's facility workers(89%) answered that there was the highest risk of 'traffic accidents', and the second risk factor was parents(carelessness of workers at children's facilities) and children's facility workers(careless of guardians at home). Looking at the risks by place, "road and sidewalk" was the most dangerous place and for child safety, guardians(64.3%) and workers (78.3%) both said that the role of "parent" is the most important. For improvements to prevent child safety accidents, the response rate of "strengthening safety management of road traffic facilities" is the most necessary with 75.8% for guardians and 65% for child use facilities. Conclusion: The reinforcement measures to strengthen the effectiveness of child safety measures are as follows. First, in order to ensure the continuity of child safety measures, it should be operated effectively so that those subject to the establishment of the Comprehensive Plan for Child Safety, which took effect in August 2022, can feel it. Second, in order to improve the sensitivity of children's policy targets, promotion measures that take into account the characteristics of each child safety field should be continuously strengthened. Third, it is necessary to expand safety infrastructure for each field to secure child safety. Fourth, it is necessary to strengthen safety education that can ensure safety for children themselves and to come up with detailed measures to make safety education for parents(guardians) mandatory.

• Land and Housing Review
• /
• v.14 no.4
• /
• pp.1-16
• /
• 2023

As population ageing and shrinking accompanied by dramatically expanded individual life expectancy and declining fertility rate is a global phenomenon, ageing becomes its broader perspective of ageing well embedded into sustained health and well-being, and also the fourth industrial revolution speeds up a more robust and inclusive view of smart ageing. While the latest paradigm of SA has gained considerable attention in the midst of sharply surging demand for health and social services and rapidly declining labor force, the definition has been widely and constantly discussed. This research is to constitute a conceptual framework of smart ageing (SA) from systematic literature review and the use of a series of secondary data and Geographical Information Systems(GIS), and to explore its components. The findings indicate that SA is considered to be an innovative approach to ensuring quality of life and protecting dignity, and identifies its constituents. Indeed, the construct of SA elaborates the multidimensional nature of independent living, encompassing three spheres - Aging in Place (AP), Well Aging (WA), and Active Ageing (AA). AP aims at maintaining independence and autonomy, entails safety, comfort, familiarity and emotional attachment, and it values social supports and services. WA assures physical, psycho-social and economic domains of well-being, and it concerns subjective happiness. AA focuses on both social engagement and economic participation. Moreover, the three constructs of SA are underpinned by specific elements (right to housing, income adequacy, health security, social care, and civic engagement) which are interrelated and interconnected.

• Korean Journal of Ecology and Environment
• /
• v.56 no.3
• /
• pp.187-195
• /
• 2023

Almost all of the water from agricultural dams located to the upper of the Yeongsan river is supplied as irrigation water for farmland and thus is not discharged to the main stream of the river. Also, most of the irrigation water does not return to the river after use, adding to the lack of flow in the main stream. As a result, the water quality and aquatic health of the river have become the poorest among the four major rivers in Korea. Therefore, in this study, several strategies for water quality improvement of the river were developed considering pollution reduction and flow rate increase, and their effect analysis was performed using a water quality model. The results of this study showed that the target water quality of the Yeongsan river could be achieved if flow increase strategies (FISs) are intensively pursued in parallel with pollution reduction. The reason is because the water quality of the river has been steadily improved through pollution reduction but this method is now nearing the limit. In addition, rainfall-related FISs such as dam construction and water distribution adjustment may be less effective or lost if a megadrought continues due to climate change and then rainfall does not occur for a long time. Therefore, in the future, if the application conditions for the FISs are similar, the seawater desalination facility, which is independent of rainfall, should be considered as the priority installation target among the FISs. The reason is that seawater desalination facilities can replace the water supply function of dams, which are difficult to newly build in Korea, and can be useful as a climate change adaptation facility by preventing water-related disasters in the event of a long-term megadrought.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.18 no.1
• /
• pp.253-270
• /
• 2023

Research on investment determinants of accelerators, which are attracting attention by greatly improving the survival rate of startups by providing professional incubation and investment to startups at the same time, is gradually expanding. However, previous studies do not have a theoretical basis in developing investment determinants in the early stages, and they use factors of angel investors or venture capital, which are similar investors, and are still in the stage of analyzing importance and priority through empirical research. Therefore, this study verified for the first time in Korea the discrimination and effectiveness of investment determinants using accelerator investment determinants developed based on the business model innovation framework in previous studies. To this end, we first set the criteria for success and failure of startup investment based on scale-up theory and conducted a survey of 22 investment experts from 14 accelerators in Korea, and secured valid data on a total of 97 startups, including 52 successful scale-up startups and 45 failed scale-up startups, were obtained and an independent sample t-test was conducted to verify the mean difference between these two groups by accelerator investment determinants. As a result of the analysis, it was confirmed that the investment determinants of accelerators based on business model innovation framework have considerable discrimination in finding successful startups and making investment decisions. In addition, as a result of analyzing manufacturing-related startups and service-related startups considering the characteristics of innovation by industry, manufacturing-related startups differed in business model, strategy, and dynamic capability factors, while service-related startups differed in dynamic capabilities. This study has great academic implications in that it verified the practical effectiveness of accelerator investment determinants derived based on business model innovation framework for the first time in Korea, and it has high practical value in that it can make effective investments by providing theoretical grounds and detailed information for investment decisions.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.17 no.4
• /
• pp.87-100
• /
• 2022

Early start-up companies have an inherent limitation of lack of resources. Despite these limitations, in order to survive, the entrepreneur's personal ability to efficiently use limited resources is required. In the marketing field, various studies are needed to reduce the business failure rate through establishing growth strategies and innovation. Accordingly, it is necessary to apply the concept of entrepreneurial marketing, which has been researched and developed overseas for 30 years, to fit the domestic reality. According to the flow of this study, an empirical study should be preceded to clarify the influence relationship between entrepreneurial marketing orientation, marketing competency, and management performance, along with a theoretical theorem on entrepreneurial marketing that is suitable for early start-ups and small and medium-sized enterprises(SMEs) and can respond innovatively to changes. The establishment of entrepreneurial marketing orientation and the processes from which this concept leads to business performance through the organization's marketing capabilities and its effects will be empirically verified. For an empirical survey, a survey was conducted on founders of 220 companies, and path analysis using structural equations was used for hypothesis verification. The findings are as follows. First, it was found that the entrepreneurial marketing orientation had a positive effect on both the organization's marketing capabilities and management performance. Second, it was found that the organization's marketing capabilities also had a positive effect on management performance. Third, as a result of empirical analysis of the mediating effect of the organization's marketing capabilities on the relationship between entrepreneurial marketing orientation and management performance, it was found that marketing capabilities showed a greater mediating effect on non-financial performance than financial performance. On the other hand, it was confirmed that marketing performance had a stronger mediating effect on financial performance than non-financial performance. By confirming and presenting the concept and constituent factors of entrepreneurial marketing orientation of domestic start-ups, which were academic gaps for the purpose of this paper, the academic research is differentiated in that they were verified as six components of entrepreneurial marketing. The practical implications of the research results will be that the entrepreneurial marketing-oriented mindset of small and medium-sized companies will optimize market analysis capabilities, network with various stakeholders, and increase the organization's ability to demonstrate marketing capabilities.