• 한국지구과학회지
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• 제42권5호
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• pp.588-603
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• 2021

This study details a researcher's self-study journey in advancing from a computational thinking (CT) novice to an expert. The researcher went through a four-stage process, with a preliminary literature review preceding the four stages. From the literature review, the computational thinking analysis (CT_AT) tool was developed for use in stage one to analyze science, technology, engineering, art, and mathematic (STEAM) modules. Although no discernable patterns were found in analyzing the five science and five engineering-based modules, the analysis revealed which CT practices were missing or weakly exposed. In stage two activities were suggested to promote these missing or weakly exposed practices. Stage three required the researcher to develop his own STEAM module from the viewpoint of exposing students to CT. The fourth stage was to validate the CT_AT through interviews with pre-service and in-service teachers. These interviews led to changes in the CT_AT tool and, as a result, the researcher produced a guidebook that could be used by teachers in their own CT studies. This guidebook can be used by teachers to develop and become competent in CT skills.

• Membrane and Water Treatment
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• 제10권1호
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• pp.67-74
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• 2019

Apparent changes in the natural hydrologic cycle causing more frequent floods in urban areas and surface water quality impairment have led stormwater management solutions towards the use of green and sustainable practices that aims to replicate pre-urbanization hydrology. Among the widely documented applications are infiltration techniques that temporarily store rainfall runoff while promoting evapotranspiration, groundwater recharge through infiltration, and diffuse pollutant reduction. In this study, a laboratory-scale infiltration device was built to be able to observe and determine the factors affecting flow variations and corresponding solids removal through a series of experiments employing semi-synthetic stormwater runoff. Results reveal that runoff and solids reduction is greatly influenced by the infiltration capability of the underlying soil which is also affected by rainfall intensity and the available depth for water storage. For gravel-filled structures, a depth of at least 1 m and subsoil infiltration rates of not more than 200 mm/h are suggested for optimum volume reduction and pollutant removal. Moreover, it was found that the length of the structure is more critical than the depth for applications in low infiltration soils. These findings provide a contribution to existing guidelines and current understanding in design and applicability of infiltration systems.

• Bulletin of the Korean Chemical Society
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• 제15권2호
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• pp.150-153
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• 1994

By treating mer, trans-Re(${\equiv}NC_6H_5)(PPh_3)_2Cl_3$, Ⅰ, with 5 atm of CO at room temperature for 52 h, fac-Re(${\equiv}NC_6H_5)(CO)(PPh_3)Cl_3$, Ⅱ, was obtained as dark green precipitates in 81% yield. The crystal structure of Ⅱ was determined through X-ray diffraction. Ⅱ crystallizes in the monoclinic system, space group $P2_1/n$ with cell parameters a=9.740 (2) ${\AA}$, b=16.210 (5) ${\AA}$, c=16.192 (6) ${\AA}$, ${\beta}$=97.50 $(2)^{\circ}$, and Z=4. Least-squares refinement of the structure led to a R$(R_w)$ factor of 0.030 (0.036) for 2878 unique reflections of I>3${\sigma}(I)$ and for 241 variables. In comparison to the starting material Ⅰ, the bond distance of Re-N became longer from 1.726 (6) to 1.736 (5) ${\AA}$ and the bond angle of Re-N-C(Ph) became smaller from 172.6 (6) to 167.0 $(2)^{\circ}$, indicating that the Re-N bond in Ⅱ is weakened and has a less triple-bond character than that in Ⅰ.

• The Journal of Asian Finance, Economics and Business
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• 제9권6호
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• pp.253-265
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• 2022

This paper examines South Korea's past developmental experience and its current strategy and policy initiatives to overcome global and domestic challenges and sustain economic growth in the twenty-first century, the digital and global era, to explain how the country became a high-income economy. The findings of this research highlight the following three factors: First, the most significant factor in rapid industrialization was the adoption of an outward-looking strategy, with the help of a highly skilled workforce and the development of high-tech manufacturing and services sectors, which was supported by the government plans. Second, the high R&D intensity helped South Korea become a global leader in information and communication technologies, which has emerged from a top-down innovation system that promotes close collaboration between government, industry, and the academic community. Third, according to the recently released Global Entrepreneurship Index, South Korea tops the region in entrepreneurship environment. Among the list of criteria, South Korea dominates in the ease of starting a business and enforcing contracts. They all play a significant role in encouraging investment, production, communication, and, eventually, economic growth. Finally, this paper suggests forward-looking developments promoting transformation and diversification into high-tech manufacturing and digital and green technologies.

• 유통과학연구
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• 제20권7호
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• pp.47-56
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• 2022

Purpose: As the need to transition into the distribution of cleaner energy has garnered corporate and scholarly interests, this study aims to track the research trends in sustainable energy supply chains for five years before 2021. Research methodology: This study was conducted by a bibliometric literature review and analysis to map the field's evolution between 2016 and 2020. Out of an initial title search result of 2,484 papers from the Scopus engine, filtering led to 180 documents obtained. The data was exported in excel format (CSV) to VOSviewer software to generate and analyze network visualization of sustainable energy supply chain trends. Results: The results revealed China's the highest publishing country, with 36 research papers. The Journal of Cleaner Production was the top publishing source, with 22 papers per year. These findings showed five clusters formed in the bibliographic coupling of countries. Circular Economy and Green Supply Chain Management represent the current hot topics. Research gaps identified in the field included limited cross-industry testing and modifying sustainable supply chain models. Conclusion: This paper contributes to the sustainability literature on supply chains by providing an overview of trends and research directions for scholars' and practitioners' consideration in future research.

• Journal of Forest and Environmental Science
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• 제26권3호
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• pp.171-179
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• 2010

Effect of chromium (Cr) stress on antioxidant enzyme activities and malondialdehyde (MDA) content were investigated in leaves and roots of mangrove (italic (L.) Druce) seedlings. Cr toxicity effects were also assessed on young seedlings. The seedlings were grown in green house condition for three months in nutrient solution with 0, 0.5, 1, 1.5, 2, 2.5, and 3 mg $L^{-1}$ $CrCl_3$. This study showed that Cr led to the change of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) and activities at different concentrations. The activity of antioxidant enzymes in leaves of K. candel seedlings indicates that enzymes engaged in antioxidant defense in certain level especially in low concentration of Cr treatments. The activities of SOD and POD were activated by Cr in the root level, while CAT activity was inhibited. CAT activity decreased in response to high concentrations of Cr. In the present study indicated that SOD in root was active in scavenging the superoxide produced by Cr. Both in roots and leaves, an increase in malondialdehyde (MDA) content was observed with increase in metal concentration and exposure periods. Our finding indicated that the high concentration of excessive Cr supply may interfere with several metabolic processes of seedlings, causing toxicity to plants as exhibited by chlorosis, necrosis, photosynthetic impairing and finally, plant death.

• Journal of Microbiology and Biotechnology
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• 제33권9호
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• pp.1250-1256
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• 2023

Herein, different extracts of Scenedesmus deserticola JD052, a green microalga, were evaluated in vitro as a potential anti-aging bioagent. Although post-treatment of microalgal culture with either UV irradiation or high light illumination did not lead to a substantial difference in the effectiveness of microalgal extracts as a potential anti-UV agent, the results indicated the presence of a highly potent compound in ethyl acetate extract with more than 20% increase in the cellular viability of normal human dermal fibroblasts (nHDFs) compared with the negative control amended with DMSO. The subsequent fractionation of the ethyl acetate extract led to two bioactive fractions with high anti-UV property; one of the fractions was further separated down to a single compound. While electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) spectroscopy analysis identified this single compound as loliolide, its identification has been rarely reported in microalgae previously, prompting thorough systematic investigations into this novel compound for the nascent microalgal industry.

• Advances in nano research
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• 제16권1호
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• pp.53-69
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• 2024

Advancements in the technology of building materials has led to diverse applications of nanomaterials with the aim to monitor concrete structures. While there are myriad instances of the use of nanoparticles in building materials, the production of smart nano cement-composites is often expensive. Thereupon, this research aims to discover a sustainable nanomaterial from tyre waste using the pyrolysis process as part of the green manufacturing circle. Here, Nano Structure Tyre-Char (NSTC) is introduced as a zero-dimension carbon-based nanoparticle. The NSTC particles were characterized using various standard characterization techniques. Several salient results for the NSTC particles were obtained using microscopic and spectroscopic techniques. The size of the particles as well as that of the agglomerates were reduced significantly using the milling process and the results were validated through a scanning electron microscope. The crystallite size and crystallinity were found to be ~35nm and 10.42%, respectively. The direct bandgap value of 5.93eV and good optical conductivity at 786 nm were obtained from the ultra violet visible spectroscopy measurements. The thermal analysis reveals the presence of a substantial amount of carbon, the rate of maximum weight loss, and the two stages of phase transformation. The FT-Raman confirms the presence of carboxyl groups and a ID/IG ratio of 0.83. Water contact angle around 140° on the surface implies the highly hydrophobic nature of the material and its low surface energy. This characteristic process assists to obtain a sustainable nanomaterial from waste tyres, contributing to the development of a smart building material.

• 한국조경학회지
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• 제47권4호
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• pp.50-60
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• 2019

1980년대 후반 녹지 및 공원경영 관련 예산삭감과 의무경쟁입찰제도(Compulsory Competitive Tendering: CCT)는 영국 도시공원의 질을 저하시키는 원인이 되었다. 1999년 도시 전담 조직(Urban Task Force, 1999), 2001년 도시공원포럼(Urban Park Forum, 2001)에 의한 공공공원평가(Public Parks Assessment)는 공원의 가치와 훼손에 대한 심각성을 경고하였고, 영국의 신노동당(The New Labour Government, 1997-2010) 그리고 보수정부(The Conservative Government 2010-2019 현재)는 부족한 공원녹지 예산문제와 공원의 질적하락 문제에 대해 커뮤니티 참여를 통해 극복하고자 하였다. 이에 따라 커뮤니티 단체 그중에서도 프렌즈 그룹과 같은 비영리 봉사단체의 공원 관리 참여 및 그 역할은 확대되었다. 그러나, 실제 이와 같은 커뮤니티 주도형 거버넌스가, 특히 거버넌스의 구축 차이에 따른 공원의 질적 향상이나 이용자만족도 제고에 어떠한 영향을 미치는지에 대한 연구에 대한 고찰은 거의 이루어지지 않았다. 이에 본 연구에서는 영국의 커뮤니티 주도형 거버넌스를 통한 공원 관리의 흐름을 고찰하였으며, 거버넌스 구축단계를 구분하고자 하였다. 또한, 사회경제적으로 불리한 지역의 영국 셰필드 2개 공원을 대상으로 이용자 설문 조사를 시행하였다. 그 결과, 영국 도시공원 관리에서의 커뮤니티 참여는 의사결정 참여를 통한 거버넌스 운영 관리 구조로 발전되었으며, 일반적, 적극적, 지배적 거버넌스형 단계로 구분할 수 있었다. 또한, 커뮤니티의 의사결정 참여의 단계에 따라 다른 수준의 책임공유가 수반됨을 알 수 있었다. 설문지 분석 결과, 거버넌스 구축단계에 따라 이용자의 공원 관리 만족도에서 차이를 나타냈다. 의사결정 참여 기회를 가지는 책임공유를 수반하는 적극적 거버넌스 구축 공원에서 이용자 만족도에 더욱 긍정적으로 작용하고 있음을 알 수 있었다. 지속적인 커뮤니티의 의사결정 참여를 통한 적극적 거버넌스 구조의 공원관리에 대한 책임공유를 바탕으로하는 파트너십, 특히 비공공 부문, 비영리 사회적 전문그룹 주도의 공원 운영 관리 방식이 도입되어야 함을 제시할 수 있다.

• 생물환경조절학회지
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• 제29권2호
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• pp.171-180
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• 2020

본 연구는 폐쇄형 식물공장에서 시금치 수경재배시 세가지의 인공광이 생육, 광합성 및 품질에 미치는 영향을 규명하기 위해 수행되었다. 세가지 광 처리구는 적색 (660nm), 청색 (450nm) 및 녹색 (550nm) LED를 사용하여, R660 / B450 = 4/1 (RBL), R660 / B450 / G550 = 5/2/3 (WWL); R660 / B450 / G550 = 1/1/1 (WL) 비율로 혼합하였고, 동일한 광도로 설정하였다 (PPFD = 190 μmol·m^-2·s^-1). 생육조사결과 초장, 엽수는 WL이 가장 적었다. SPAD, 순광합성율, Fv/Fm, LAI, 근권부 생육은 RBL이 가장 높았고 통계적으로 유의하였다. 줄기, 잎, 뿌리의 생체중, 뿌리의 건물 중은 세가지 처리구에서 유의한 차이를 보였다. 대조적으로 WL의 칼륨의 함량은 WWL과 RBL 가운데 가장 높았지만, 반면 칼륨과 철의 함량은 RBL이 가장 높았다. 비타민C 함량도 시험구간 유의한 차이를 보였다. 질소와 옥살산 함량은 WL이 가장 높았고, 용해성 고체와 비타민C 함량은 RBL이 가장 높았다. 옥살산, 질소 함량은 WWL에서 감소하는 경향을 보였고, RBL의 옥살산 함량은 WL와 WWL과 차이가 없었다. 모든 처리구에서 Salmonella, E.coli.는 감염되지 않았다. 결론적으로, RBL이 시금치의 생육에 적합하지만, 적색, 청색과 적정하게 혼합된 녹색광은 시금치의 생육에 긍정적인 영향을 미친다고 판단된다.