검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 9

        3.
        2017.10 구독 인증기관·개인회원 무료
        운문산 일원은 자연공원법에 의해 지정된 운문산 군립공 원과 자연환경보전법에 의해 지정된 운문산 생태경관보전 지역이 있다. 운문산 군립공원의 면적은 16.173㎢ 이며 관 리주체는 경상북도 청도군이고, 운문산 생태경관보전지역 의 면적은 26.395㎢ 이며 관리주체는 대구지방환경청이다. 이러한 보호지역이 중첩된 지역의 면적은 10.3㎢ 로 운문산 군립공원 전체 면적의 64%를 차지하며 출입금지구역으로 지정하여 엄중히 관리하고 있다. 1990년 이후 시행된 운문 산 자연휴식년제를 통해 탐방객의 출입을 제한함으로써 가 지산 등 인근지역에서 발견되지 않았던 법적보호종들(수달, 담비, 하늘다람쥐)이 출현하였으며 포유류의 서식에 필요한 매우 양호한 자연생태계를 갖춘 지역이 되었다. 멸종위기종 포유류의 지속가능한 보호를 위해 다양한 보호 지역 관리체계를 갖춘 운문산 군립공원에서 보호지역 관리에 대한 효과성 연구가 필요하다. 본 연구는 이러한 보호지역 관리가 멸종위기종 포유류에 미치는 영향을 알아보기 위해 운문산 군립공원을 대상으로 엄중한 관리 지역(중복 지정 지역), 관리 지역(독립 지정 지역) 그리고 비관리 지역(공원 외 지역)으로 나누어 선조사법(Line transect)을 통해 출현하 는 멸종위기종 포유류 흔적의 상대빈도를 조사하였다. 연구결과 지역별 멸종위기종 포유류 흔적의 상대빈도는 중복 지정 지역에서 425회/㎢, 독립 지정 지역에서 92회/㎢, 공원 외 지역에서 37회/㎢ 로 중복 지정 지역처럼 탐방객 출입이 엄중히 관리되는 곳에서 흔적이 많이 관찰되는 경향 이 나타났다. 본 조사는 1회 실시되어 통계적 유의성을 알 수 없지만 반복 조사를 통해 보호지역 관리체계에 따른 멸 종위기종 포유류 분포의 상관관계를 이해할 수 있을 것으로 판단된다.
        4.
        2015.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A dynamic tube pressure method was proposed for a liquid level measurement. The reliability of our in-house manufactured prototype level measurement system was investigated for water samples in a vial as a preliminary study. The prototype instrument, equipped with a stepper motor and a differential pressure sensor, was used to measure the travel distance of the tube from an initial zero position to the liquid surface. Unlike a conventional bubbler method, our dynamic tube pressure method is based on the abrupt changes in the tube pressure to directly detect the liquid surface. Optimum conditions were determined from the measurements of the travel distance with different-sized tubes at various ambient base pressures and various descending tube speeds. In addition, we proposed a gravimetric calibration method. In the gravimetric calibration method, the travel distances are used instead of the liquid level, which can be obtained from the measurement data of the travel distance. The travel distance versus the weight calibration curve showed a good linear relationship (R2 = 0.9999), and standard deviations of the travel distance over the whole range of experimental conditions were less than 0.1 mm. In a further study, our present system will also be used in the measurement of density and surface tension by minimizing the contact time with high-temperature and highly-corrosive molten salts.
        4,000원
        5.
        2015.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        원자로의 해체 과정에서 발생되는 방사성 폐기물 내 존재하는 55Fe, 63Ni은 폐기물의 처리방법을 결정하는 데 있어 기초적인 지표로 활용되는 중요한 핵종이다. 하지만 두 핵종은 낮은 방사선량으로 인해 다른 핵종들과의 분리가 필수적이며 또한 시 료 매질에서 완전히 추출할 수 있는 전처리가 선행되어야 한다. 따라서 본 연구는 다양한 매질의 원자로 해체 폐기물에 대한 전처리방법의 적용성을 평가하기 위해 NIST SRM 5종 (1646a, 1944, 8704, 2709a, 1633c)에 대하여 왕수, 불산, 과염소산을 각각 이용하는 습식산화법과 alkali-fusion 전처리법에 따른 Iron와 Nickel의 회수율을 비교하였다. 실험 결과 alkali-fusion 방법은 다양한 매질의 인증표준물질에 대해 Iron 95.3~98.3%, Nickle 86.6~88.1%의 분석 정확도와 2% 이하의 정밀도를 나타냄으로서 해체폐기물 중 55Fe, 63Ni 분석에 가장 최적화된 전처리법으로 판단된다.
        4,000원
        6.
        2018.01 KCI 등재 서비스 종료(열람 제한)
        In this research, we present a new methodology to indirectly assess the concentration levels of the biochemical oxygen demand (BOD) and total nitrogen (T-N) of dewatered cake by evaluating the amounts of the volatile solids (VS) and total solids (TS). Information regarding the BOD and T-N concentrations of dewatered cake could then be used to estimate the Greenhouse Gas (GHG) emissions caused by sewage treatment. To this end, regression equations were derived by considering the relationship between the product of two solid terms: (TS × VS) and BOD/T-N levels of digested sludge. The optimal regression equations for BOD and T-N were computed as y = 152425x (R2= 0.969, p < 0.05) and y = 128378x (R2= 0.970, p < 0.05), respectively. For the purposes of verification, the applicability of the regression equations was tested using the data for other periods not considered in the regression analysis. Accordingly, the differences between the measured and estimated concentration data (derived using the regression equations) were within the standard deviation of the measured concentrations. However, the concentrations estimated by regression equations were quite different from those obtained by conventional methods. Nonetheless, such differences did not significantly change GHG emissions, thus we conclude that the plant specific regression equations can be derived from the methods presented in this study, although more efforts are needed for its validation in various respects.
        7.
        2016.01 KCI 등재 서비스 종료(열람 제한)
        Aluminum can is one of the common and economically valuable recycling items in municipal waste streams. In this study, the reduction rate of the greenhouse gas emission and energy savings were estimated when aluminum cans are recycled by using material flow analysis, US EPA WARM method, and EU Prognos method. Based on the results, approximately 16,630 ton of aluminum in 2010 was recovered as ingot, while 10,873 ton of aluminum can to can recycling occurred in the same year. The reduction rate of aluminum recycling was estimated to be 240,986 tCO2eq/yr by US EPA WARM method, while about 305,283 tCO2eq/yr was found by the recycling using EU Prognos method. The difference resulted partly from the different system boundary and the loss rate during aluminum recycling process. The results of the energy savings and greenhouse gas reduction rate would be valuable for waste management policy makers to estimate the potential reduction rate of greenhouse gas by aluminum can recycling and accelerate recycling infrastructure of waste streams. This study also implies that the applications and results of both methods to estimate greenhouse gas reduction rates by aluminum can recycling should be carefully reviewed and acknowledged before the use of the method due to the different assumptions and results that are anticipated.
        8.
        2015.10 KCI 등재 서비스 종료(열람 제한)
        With a growing concern of greenhouse gas (GHG) emissions due to climate change, many activities and efforts onthe greenhouse gas reduction have been implemented in solid waste sectors. Since recycling is the major managementoption for solid waste in Korea, it is important to estimate the reduction of the greenhouse gas emission during recyclingprocesses. In this study, two common methodologies, Prognos method of EU and waste reduction model (WARM) methodof USA, have been critically reviewed and compared to estimate the reduction for recycling of waste paper in terms ofsystem boundary, recycling processes, and emission factors. As a common point of two methodologies, the reductionfactors for the paper recycling have been developed by subtracting the recycled product emissions from the virgin productemissions to get the greenhouse gas savings. While the recycling losses and transportation are considered in twomethodology development, there are a number of differences between the methodologies in system boundary,transportation distance and forest carbon sequestration. As a result, it caused the difference in final greenhouse gasreduction factor of paper recycling. The reduction factor was −820kgCO2eq/ton in Prognos method, while −3,891kgCO2eq/ton was found in the WARM method. When both methods were applied to recycling of waste paper in Korea,the greenhouse gas reductions by the Prognos method and the WARM method were found to be 3,485.2tCO2eq/day and2,248.8tCO2eq/day, respectively. When the carbon sequestration by forest is considered in the WARM method, thereduction rate was estimated to be 16,538.3tCO2eq/day. The main reasons for such difference can be attributed to systemboundary and forest carbon sequestration. Especially, forest carbon sequestration can be an important factor in Korea thatusually manufactures papers from imported pulp from abroad. This study implies that the applications and results of bothmethods to estimate greenhouse gas reduction by waste recycling should carefully reviewed and acknowledged beforeuse due to the different assumptions and results that are anticipated.
        9.
        2004.05 KCI 등재 서비스 종료(열람 제한)
        Two compounds from Gomisin N and Gomisin A were isolated from the fruits of Schizandra chinensis Baillon. The highest extraction yield as 21.36% was observed in the ethanol extract, compared to the yield obtained form the water extract. The extraction yields of the single compounds were measured to be 0.13 and 0.014 Gomisin A and Gomisin N, respectively. Approximately, 90% of the growth of human stomach adenocarcinoma cancer cells was inhibited after adding 1.0 g/l of the ethanol extract. The growth of the human normal lung cell was limited to 24% after adding the ethanol extract. The water extract lowered the specific secretion of TNF-á and IL-6 from T cells, 10.3×10-4 pg/cell and 12.1×10-4 pg/cell, respectively, compared to the ethanol extracts. On the other hand, a treatment with the ethanol extract increased the specific secretion of TNF-á and IL-6 from human T cells, to 11×10-4 pg/cell and 14.3×10-4 pg/cell, respectively. The crude ethanol extract had the highest effect on the differentiation of human promyelocytic leukemia cells compared to the other extracts and Gomisin A and N. In general, the biological activities of the extracts gradually decreased as the purification process proceeded, which suggests that higher immunostimulatory activities can be maintained by adding the crude extracts of the fruits rather than by adding a single compound.