• Environmental Analysis Health and Toxicology
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• 제14권4호
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• pp.145-153
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• 1999

Effects of various concentrations of copper in solid fibrous form and methylglyoxal (MG) on phosphorus uptake and growth change of green algae Scenedesmus obliquus were studied. There was significant differences among cultures treated with various concentrations of copper and MG in growth of algae with parameters of cell numbers, photosynthetic rate and cellular morphology, and phosphorus uptake by cell. When the copper in media is treated with 25 mg or 50 mg per 100 ml of Bristol solution, the mean cell number of algae was 15.642${\times}$10$\^$6/ cells$.$ml$\^$-1/ and 12.986${\times}$10$\^$6/ cells$.$ml$\^$-1/, respectively, while those of algae in culture without copper was 18.486${\times}$10$\^$6/ cells$.$ml$\^$-1/. The mean cell area of 2450 ${\mu}$m$^2$, 1894 ${\mu}$m$^2$and 1697 ${\mu}$m$^2$in basic media, basic media with 25 mg of copper and basic media with 50 mg of copper was showed the inhibitory effect of copper on algal growth. The algal growth was stimulated by MG when the culture was treated with 25 mg of copper or without copper, while it was inhibited when the culture was treated with 50 mg of copper. It was considered that there was significant interaction between copper and MG on algal growth. The phosphorus concentration in algal medium treated with 25 mg or 50 mg of copper was 29.435 ppm and 26.224 ppm, respectively, while those of algae in culture without copper was 52.8 ppm, which shows that the application of copper in algal medium can prevent the availability of phosphorus to algal cell.

• 한국환경생태학회지
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• 제23권2호
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• pp.127-134
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• 2009

본 연구는 변산반도국립공원에서 활용되고 있는 각종 환경해설 매체에 대한 탐방객 인식을 파악하여 효율적인 공원관리 기초자료 제공을 목적으로 수행하였다. 이를 위해 탐방객 직접기입 방식의 설문조사를 실시하였고 총 291매의 설문지가 유효 표본으로 이용되었다. 조사결과 '탐방지원센터 전시물'이 가장 이용률이 높은 환경해설 매체로 나타났으며 '수목이름 해설판', '자연해설 프로그램'은 비교적 높은 이용률을 보였다. 그러나 공원안내지도'는 이용 효율성이 떨어지는 매체로 평가되었다. 공원내 환경해설 매체에 대한 중요도-성취도 분석 결과 중요도 평균값은 3.64, 성취도 평균값은 3.03으로 치악산과 월출산국립공원에서 조사한 결과보다 낮았다.

• The Journal of Asian Finance, Economics and Business
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• 제7권10호
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• pp.989-998
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• 2020

Electronic commerce is becoming a significant hub for sourcing products/services which helps organizations to connect with potential customers and gain competitive advantages, though little empirical work focuses on small businesses operating in developing countries to date. Increasingly, companies are looking to utilize social media to connect with stakeholders and pursue several benefits. This study aims to investigate the technological, organizational, and environmental (TOE) factors that influence small- and medium-sized enterprises' (SMEs) social media (SM) adoption in developing countries. This study used a closed-ended questionnaire to collect data from randomly-selected respondents (owners, executives, and managers) from SMEs in Pakistan. SMART PLS version 3.2.8 was used for path analysis of 316 responses and for structural equation modeling. The research findings include the direct influence of TOE factors (relative advantage, interactivity, visibility, top management support, and institutional pressure) on SMEs' SM adoption, and in turn SM adoption also has a positive influence on SMEs performance. Moreover, the coefficient of determination of the study showed that 77.7% of the variation in SM adoption occurs because of TOE factors and 29.8% variation in SMEs occurred because of SM adoption. This paper has implications for practitioners and scholars interested in exploring the SM adoption and usage by SMEs.

• 한국지하수토양환경학회지:지하수토양환경
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• 제29권1호
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• pp.72-83
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• 2024

Most of the slags generated from steel-making industry in Korea are recycled into media-contact aggregates such as fill and cover materials. For their use as media-contact aggregates, the slags must meet not only the waste quality criteria, but also the Daphnia magna acute toxicity test criteria. In this study, Korean Leaching Test ES 06150.e (Korea), Japanese Leaching Test JIS K 0058-1(Japan), Detuch Leaching Test DIN 19529 (Germany), Toxicity Characteristic Leaching Procedure (USA) were conducted for batch leaching test of slags from 6 Korean steel-making companies. In addition, Korean Standard up-flow percolation test (ES 06151.1) mimicking field conditions was conducted to assess the impact of the slag leachate on the surrounding environment indirectly. Heavy metals such as Cr⁶⁺ and Zn²⁺ were detected from both extractant and leachate samples, but all of them did not exceed waste quality criteria of each country. However, Daphnia magna acute toxicity tests using the leachate samples from up-flow percolation test with slag alone and slag/natural soil conditions exceeded ecotoxicity standard (TU=2) due to their high pH (11.3-12.5). After neutralizing the pH of the slag leachate to 6.5~8.5, the Daphnia magna mortality and immobilization were reduced to satisfy ecotoxicity standard. As the reducing pH of slag leachate would be extremely difficult, appropriate recycling management considering the physicochemical characteristics of he slags should be stuided further.

• 한국지구과학회지
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• 제25권3호
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• pp.185-193
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• 2004

The purpose of this study is to explore high school students' environmental literacy and from its result, to suggest ways to reform environmental education. 1047 students from Seoul and Kyeongki province participated in the survey. The questionnaire consisted of four criteria of environmental literacy including knowledge, skill, attitude and behavior. The result was analyzed and the factors which affect high school students environmental literacy were explored. From this result, we made suggestions to improve environmental education as follows. First, environmental education in school should focus on knowledge criterion. Though school environmental education has been helpful for students to build environmental literacy in attitude and behavior criteria, its effect has not been good enough in knowledge criterion. Second, science education can enhance students' environmental literacy. Students who like science best and students who belong to science major classes were reported to possess better understanding in knowledge criterion. Also, students who like life science appeared to have a more positive attitude in environmental literacy. Third, informal education must be considered to form students' environmental literacy. In particular, the effect of mass media is inarguable. Thus, we should find a way to link formal education and informal education to improve environmental education. Fourth, high school students' interest in the environment must be encouraged since it is evident that higher interest would result in better outcome in environmental education.

• 한국언론정보학보
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• 제43권
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• pp.152-172
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• 2008

기본적으로 미디어 공익성이라는 개념은 사회적 차원에서 미디어에 대한 비판적 대응과 관리, 통제를 위해 확립된 이념체계, 즉 사회적 이익의 실현을 위해 미디어에 개입하는 철학적 근거로 기능해오고 있다. 그러나 문제는 공익성 철학을 미디어 융합시대에 걸맞은 현실의 정책으로 해석 적용하기 위한 수많은 논의와 연구에도 불구하고 실제 제시되는 구체적 정책내용이나 방안은 융합환경 이전이나 이후에도 사실상 유사하다는 점이다. 이 같은 한계는 여러 이유가 있겠지만 공익성의 제도화 관련 논의가 대체로 미디어에 대한 도구적 관점에 기초해있기 때문이라고 할 수 있다. 그러나 미디어는 도구, 또는 도구의 집합 이상의 의미를 갖고 있으며 이는 '미디어 과잉'이라는 사회적 상황을 조성하고 있는 융합시대에 들어 더욱 분명해지고 있다. 이러한 문제의식에서 출발하는 이 연구는 공익성과 관련한 기존의 정책과 정책논의가 가지고 있는 미디어에 대한 시각과 인식의 한계를 '미디어-환경'개념에 입각해 반성적으로 짚어보고자 한다. 미디어-환경개념은 말 그대로 미디어를 환경, 특히 '문화적 생태환경 체제'로 인식하는 것을 의미한다. 미디어에 대한 환경론적 접근은 융합시대에 요구되는 미디어 공익성 관련 정책의 철학적 기초와 내용을 보다 풍성하게 하는 한편 공익성의 실천적 기준과 주체의 범위를 더욱 확대해준다는 점에서 그 의의를 찾을 수 있다.

• 한국환경농학회지
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• 제41권3호
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• pp.191-198
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• 2022

BACKGROUND: Plants can be grown using a culture medium without soil using a hydroponic system. Crop production by the hydroponic system is likely to increase as a means of solving various problems in the agricultural sector such as aging of rural population and climate change. Different water sources can be used to prepare the culture medium used in the hydroponic system. Therefore, it is necessary to study the effect of different water sources on crop production by the hydroponic system in order to explore the applicability of various water resources. METHODS AND RESULTS: Lettuce was cultivated by the hydroponic system and three different water sources [tap water (TW), bottled water (BW), and groundwater (GW)] were used to compare the effect of water sources on lettuce growth. The three kinds of waters with a nutrient solution (TW-M, BW-M, GW-M) were also used as the media. After the six-week growth period, the lettuce length and weight, the number of leaves, and the contents of chlorophylls and polyphenols were compared among the different media used. The lettuces did not grow in the waters without the nutrient solution. In the media, the lettuce growth and the contents of chlorophylls were affected by the different water sources used to prepare the media, while the contents of polyphenols were not affected. The absorbed amounts of ions by lettuces, especially Ca and Zn ions, and the dry weight of the harvested lettuces showed a strong positive correlation. CONCLUSION(S): Overall, this study shows that different water sources used for growing lettuce in a hydroponic system can affect lettuce growth. Further studies on the enhancement of crop qualities using different water sources may be required in future studies.

• 한국환경농학회지
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• 제22권3호
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• pp.233-235
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• 2003

[ $2000{\sim}2001$ ]년 우리나라에서 유통되고 있는 원예용 상토 53점을 수집하여 농자재 중금속 분석 시험법인 전함량분석법과 토양의 중금속 공정시험법인 0.1N HCl 용출법에 의해 분석 상토중 중금속 함량을 분석하였다. 시판 원예용상토에 대한 중금속의 전함량 분석에서 카드뮴, 크롬, 구리, 니켈 납, 아연의 평균함량과 범위는 건토기준으로 각각 0.69($0{\sim}1.82$), 35.68($0{\sim}259.80$), 14.91($1.64{\sim}69.45$), 15.48($0{\sim}60.72$), 12.70($0{\sim}36.45$), 및 54.84($12.90{\sim}124.0$) mg/kg 이었다. 0.1N HCl 침출성 중금속 평균함량과 범위는 카드뮴이 0.08($0{\sim}0.20$), 크롬 0.38($0{\sim}2.10$), 구리 1.45($0{\sim}4.03$), 니켈 ($0.850{\sim}3.31$), 납 0.84($0{\sim}2.21$), 아연 30.68($0.18{\sim}88.45$) mg/kg 이었다. 조사된 모든 원예용상토의 중금속 함량은 부산물비료 허용기준 및 토양오염 우려기준보다 낮은 수준을 보였다.

• 한국환경복원기술학회지
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• 제11권4호
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• pp.119-128
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• 2008

In this study, we attempted to seek out the ways to recycle fresh root-chips in the slope revegetation works by breaking tree root wastes occurring during the construction works, also to review the applicability of fresh root-chips as the soil media in slope revegetation works. For this purpose, we organized test units in order to investigate on-site applicability of fresh root-chips (broken chips). In order to examine the desirable ration of combining fresh root-chips with the hydroseeding soil media on the cutting slopes, we organized test units depending on the amount of combination. The following is the main experimental results. 1. At first, we analyzed properties of hrdro-seeding soil media and soil of the experimental sites. The overall results demonstrate that all the test units show proper range for vegetation. 2. We believe that the physical properties of soils in the earlier phase of restoration works on the sloped sites are not greatly affected by the fact whether broken chips exist or not. However, as time elapses, broken chips needs to be investigated further on what kind of impact they have on the soil condition. 3. More species are found in the test unit combining broken chips and we believe that it will contribute to blossoming of green plants and ecological succession of neighboring plants. 4. We performed experiment on possibility for fresh root-chips as substitutes for the hydro-seeding soil-media. In the test unit that combines fresh root-chips, its mixture ratio tends to exceed that of the test unit that does not combine fresh root-chips by 5 %. In case of the Thick-Layer-Soil-Media Hydroseeding works, the mixture ratio of the test unit that combines fresh root-chips after 16 weeks exceeds that of the test unit that does not combine fresh root-chips by 75%. 5. From the result of our experiment, it is obvious that the ratio of mixture and the number of emerging species are higher for the test unit combining fresh root-chips than the test unit that does not combine them. In other words, we can replace the hydro-seeding-soil-media with some Fresh root-chips without affecting the physical property of soil.

• 한국지구과학회지
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• 제27권7호
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• pp.705-714
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• 2006

The purpose of this study was to explore the elementary students' perceptions of Earth systems and environmental issues. A survey was conducted to determine the students' perceptions on the following aveas: (1) the concepts of certainty and tangibility, (2) self-reported knowledge level, (3) perceived danger level of selected eight Earth systems and environmental issues, and (4) their primary information source on these issues. Results indicated that ozone hole, acid rain, El $Ni\widetilde{n}o$, and global warming were identified by the students as uncertain and intangible issues. Perceived certainty and perceived tangibility were highly positively correlated with self-reported knowledge compared to other relationships. The results also showed that learning from school was the most frequent information source for environmental issues. The second most frequently used source of information was television among several mass media sources. It is hoped that this study contributes to understanding the elementary school students' perceptions toward the selected Earth systems and environmental issues.