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        검색결과 155

        122.
        1993.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to examine substrate removal characteristics with the variation of the hydraulic retention time in an anaerobic filter. The feed concentration of synthetic wastewater used in the experiment was $10,000mg/l$ glucose. As media, the porosity of volcanic stones in Jeju island were 76%. The conditions of the experiment were as follows; HRT ranging from 1 day to 3 day, loading rates ranging from 3.33kg $COD_{er}/void\;m^3.day$ to 10kg $COD_{er}/void\;m^3.day$ and a temperature $35^{\circ}C$. Based on the results of the experiments, the COD removal efficiency was 98~99% in $COD_{er}$ method with loading rates ranging from 3.33kgCOD/void $m^3.day$ to 10kg COD/void $m^3.day$ and HRT ranging from 1day to 3 day. The produced quantity of gas equivalant to a porosity volume was $1.332~3.756Nm^3/void\;m^3.day$. The relationship between $COD_{er}$ loading rates and gas produced quantity equivalant to a porosity volume was well fitted with the equation of $Nm^3/void\;m^3.day{\cdot}=0.359L_0+0.179$($L_0=COD$ loading rate). Judging from the removal efficiency in this experiment, We concluded that anaerobic filter using Volcanic stones is one of improved and effective. As media, practical value of volcanic stones is sufficient.
        4,000원
        124.
        2019.06 KCI 등재 서비스 종료(열람 제한)
        The primary purpose of this study was to investigate the relationship between elementary school students’ self-confidence in English as a foreign language and their assessment of English teaching taught by native speaker English teachers. A total of 126 elementary school students were asked on a 5-point Likert scale instrument to assess their native English teachers in terms of their teaching ability, provision of opportunity to use English, classroom management, and language assessment ability. In addition, the subjects were asked to rate how much they were confident with their English. All of the responses were submitted to the SPSS 22 version for statistical analyses. Firstly, the subjects were divided into 3 groups based on how much they felt confident with their English. Secondly, a MANOVA was run to investigate any group differences in how they perceive their native speaker teachers’ teaching ability, provision of opportunity, and language assessment ability. The results indicated that language confidence was indeed an important variable not only in subjects’ learning English but also how they perceived their English learning experience as a whole. Pedagogical implications for improving elementary school children were also discussed.
        126.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        Youngcheol Kim and Jaewoo Shim. 2017. Discriminant Analysis of Satisfaction Levels with Native Speaker Instructors Held by Elementary School Pre-service Teachers of English. Studies in Modern Grammar 96, 235-251. The current study investigated the levels of satisfaction with native speaker teachers of English that were perceived by a group of elementary school pre-service teachers of English in a teachers college. 79 subjects responded to a Likert-type questionnaire with 15 items aimed to assess their satisfaction with their current and former native speaker teachers on their campus. The questionnaire measured the four aspects of teaching: the ability to teach, the ability to offer learning opportunities, the ability to manage and create friendly classroom climate, and the ability to assess their performance. The discriminant analysis was used to identify aspects that separated satisfied from unsatisfied groups of students. The results of the discriminant analysis showed that two independent variables (i.e., the native speaker teachers’ ability to offer learning opportunities and their ability to teach) were statistically significant variables in separating the two groups. These findings indicated that native speaker teachers of English need to make efforts to design lessons that may prompt active student participation, while keeping high levels of teaching ability congruent with students’ expectations.
        127.
        2015.10 KCI 등재 서비스 종료(열람 제한)
        To produce high quality watermelon, three tetraploid watermelon breeding lines (‘SA03-1’, ‘SA06-1’ and ‘SB01-1’) were developed by treatment with different chromosome doubling reagents. To identify the optimal tetraploid inductive conditions, the three watermelon breeding lines were selected by counting the number of doubled chloroplasts in guard cells. Tetraploid induction rates differed depending on the genotypes and treatment with doubling reagents. However, the highest induction rate occurred with 1.0% colchicine (82.2%). These putative tetraploid lines were re-confirmed for ploidy using flow cytometric analysis and chromosome counting. The internode length of the tetraploid breeding lines was different when the leaf size was larger in all three tetraploid lines compared to their diploids. The fruit weight of the tetraploid fruits for ‘SA03-1’ and ‘SB01-1’ was lower than for their diploid, and the rind thickness and total sugar content (°Brix) of tetraploid SB01-1 were significantly different from those of its diploid. Tetraploid lines were sterile, yielded a lower number of seeds per fruit for ‘SA03-1’ (21), ‘SA06-1’ (62), and ‘SB01-1’ (34.7), and the seeds were larger and thicker than those of their diploids. These tetraploid breeding results will be useful for breeding new seedless watermelon cultivars.
        129.
        2012.02 서비스 종료(열람 제한)
        도시화에 따른 불투수 면적의 증가는 개발이전에 비해 더 많은 강우 유출 및 수질악화를 초래하여 적절한 관리방안에 대한 관심이 높아지고 있다. 이에 대한 대안으로써 대두되어진 최적화관리기법(Best Management Practices, BMP)은 이러한 비점오염물질과 강우유출수를 저감하기 위한 방안으로 국내·외에서 많은 연구가 진행되고 있다. BMP 적용을 통한 목표 저감효과를 달성하기 위해서는 BMP별 성능을 비교분석하고 대상유역에 적합한 BMP를 선정하여 설계해야 한다. 현재 이와 관련한 모니터링 연구가 활발히 진행 중에 있으나 유역별로 기후와 지형조건이 상이하고, 미계측 유역의 경우 BMP 성능 예측에 한계가 있다. 이를 극복하기 위해서는 모니터링 연구와 더불어 대상유역의 기상조건과 지형 조건을 고려한 BMP 모형화 기법을 이용한 BMP 별 성능을 분석하는 방법이 필요하다. 본 연구에서는 국내·외에서 강우유출수의 모의에 많이 이용되고 있는 SWMM(Storm Water Management Model) 모형을 이용하여 충청남도 대천항 주차장을 대상으로 BMP 성능 모의를 실시하였다. 모형의 적용성 평가를 위해 국제 우수 BMP Database에 수록되어 있는 사례의 결과와 식생저류지(bioretention) 및 투수성 포장(porous pavement)의 가상설치 시 예측되는 수문 및 수질 저감효과를 비교하였으며, 유출 및 수질 항목별 평균저감율 편차 범위가 -5.8∼+9.6%로 높은 적용성을 보였다. 향후 BMP 설계 및 저감효과 산정에 본 연구에서 제시한 BMP 모의 방법론의 활용이 가능할 것으로 판단된다.
        130.
        2010.12 KCI 등재 서비스 종료(열람 제한)
        Root yield and quality of ginseng cultured in paddy soil was low relatively compared with that of upland soil because of moisture injury in root during rainy season. Drainage class in soils generally divided into 6 classes, and it is possible to cultivate ginseng practically in imperfectly drainage class (IDC). This study carried out to select the varieties that is suitable for paddy soil, which is easy to be generated rusty-colored root and physiological-discolored leaf. Experiment plot arranged with the condition of soil humidity contents such as poorly drainage class (PDC) and imperfectly drainage class (IDC), and upland soil. Growth characteristics and root yield were investigated in four-year-old ginseng of varieties, Cheonpoong (CP), Yeonpoong (YP), Hwangsookjong (HS), and Jakyeongjong (JK). CP among four varieties showed the highest yield in IDC and CP was the lowest ratio in leaf discoloration and rusty-colored root. HS was followed by CP in the order of root yield, but it had the weakness that the ratio of rusty-colored root was high respectively.
        131.
        2010.10 KCI 등재 서비스 종료(열람 제한)
        Root extract of Lythrum salicaria reported a hepato-protective effect on CCl4-induced liver toxicity of rat was prepared into fractions such as n-hexane up layer (HA), n-hexane down layer (HB), diethyl ether (E), ethylacetate (EA), n-butanol (B) and water (W). Fractions prepared were tested their activities in vitro and in vivo condition. All of the fractions showed effective antioxidant asctivities on DPPH radical and CuSO4-induced oxidation of human low density lipoprotein and E fraction showed the highest inhibitory effect (98.1% at 50 μg/ml) on linoleic acid autoxidation at 40℃, which was more effective than α-tocopherol (82.4%). Five fractions (H = HA plus HB, E, EA, B, and W, 150 mg/kg/day) were fed into Sprague Dawley, male rats for 4 days, which were intoxicated with intra-peritoneal injection of carbon tetrachloride (1 ml/kg in corn oil) at the 4th day and were sacrificed in 24 hrs. Serum tumor necrosis factor-alpha (TNF-α), a proinflammatory cytokine, elevated with CCl4-intoxication in negative control group (83 pg/ml) was significantly decreased in E fraction-supplemented group (18 pg/ml). Cu, Zn-superoxide dismutase (SOD) activity increased in negative control group (0.12 U/mg protein) was decreased in E fraction (0.07 U/mg protein). From the results, it is suggested that ether fraction from root extract of L. salicaria would be a potent antioxidant candidate for ameliorating liver injury induced by chemical intoxicant.
        132.
        2010.10 KCI 등재 서비스 종료(열람 제한)
        For the investigation of possibility as a useful functional material, different parts of Lythrum salicaria L. harvested at four growth stages were studied in the aspect of bleeding characteristics, chemical composition and in vitro activity. Weights (g/plant) of L. salicaria plant parts were high in order to stem 〉 leaf 〉 flower 〉 root at the best growth time. Crude lipids (3.59~4.30%) and crude proteins (14.7~23.5%) of L. salicaria leaves were the highest among the other plant parts showed from 0.08~3.54%, and 4.0~21.9%, respectively. Free sugars (2.9~4.2%) and crude ash (11.9~14.8) of leaves also showed the highest value. Free radical scavenging activities of L. salicaria root on 2,2-diphenyl-1-picrylhydrazyl showed from 43.5 μg/ml to 47.6 μg/ml as IC50 which were followed by those of flower, leaf, and stem. Root of L. salicaria tested at 100 μg/ml also showed the most efficient inhibitory effect on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in murine macrophage RAW264.7 cells. Cell viability of the plant parts tested by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyl tetrazoliumbromide (MTT) assay was high in order to flower, leaf, root, and stem. Total phenol content measured as tannic acid equivalent showed the highest value in flower. In conclusion, among the plant parts, especially leaf of L. salicaria, was rich in the chemical components, and showed efficient antioxidant/inhibitory activity on free radical and NO production, and was expected to be a functional material candidate.
        134.
        2009.12 KCI 등재 서비스 종료(열람 제한)
        인삼 논재배 안전생산기술을 개발하기 위해 배수불량지와 배수약간불량지 논토양에서 청3+흑1중직 차광망, 청색차광지 및 은박차광판 해가림을 처리하여 3년생 천풍의 생육특성 및 진세노사이드 함량을 조사한 결과는 다음과 같다. 해가림 유형별 투광량과 기온은 차광지 > 은박차광판 > 차광망 순이었다. 배수불량지의 토양수분장력은 평균 64mbar (절대토양수분함량 25%)로 과습한 조건이었으며, 배수약간불량지에서는 평균 123 mbar (절대수분함량 17%)이었다. 배수불량지의 토양수분장력은 계절과 해가림 유형별 뚜렷한 차이를 보이지 않았지만 배수약간불량지에서는 60~200 mbar의 범위에서 계절적 변화를 보였으며, 해가림유형에 따라 약간의 차이를 보였다. 배수불량지의 수량성은 황증과 적변 발생율의 증가로 배수약간불량지보다 현저히 감소되었다. 해가림 유형별 수량성은 배수불량지에서 차광지가, 배수약간불량지에서 차광망이 가장 높았다. 적변 발생율은 배수등급과 해가림 유형에 따라 일정한 경향이 없었다. 배수불량지는 Panaxatriol 계열 (Rg1, Re 및 Rf)의 진세노사이드 함량이 감소되고 Panaxadiol 계열 (Rb1, Rc 및 Rd)의 함량이 증가되었다. 총 진세노사이드 함량은 배수불량지보다 배수약간불량지에서 높았으며, 해가림 유형별 총 진세노사이드 함량은 배수등급에 관계없이 차광지에서 가장 높았다.
        135.
        2009.12 KCI 등재 서비스 종료(열람 제한)
        This study was to set the guidelines of soil chemical components in order to assure the safety and quality ofthe panax ginseng from physiological disorder. The disorder symptoms appeared on the leaf with yellow spot, atrophy, yel-low-brown spot, also showed red skin and rough skin of the root. Occurrence type of physiological disorder in cultivatedfield divided into two types:type I ‘such as, yellow spot’ consist of single disorder symptom; type II ‘such as, yellow spotand yellow-brown spot’ consist of two or more different disorder symptoms. The individual contribution of soil properties tothe occurrence type was as follows ; The yellow spot was affected by Na>NO3-N>salinity (EC) in soil. The same results wasobserved in red skin. Atrophy was affected by NO3-N>salinity (EC)>Ca>Mg. Rough skin was affected by P2O5>pH>Organic material > K. It showed positive associated to P2O5, pH and K, but negative associated to organic matter. Simulta-neous occurrence of two different disorder, including cases which yellow spot and yellow-brown spot, those were affected byNO3-N > salinity (EC) > Na > Mg. In the case of atrophy plus yellow-brown spot, those also were affected by in the order :NO3-N > salinity (EC) > Ca > Mg > Na. Red-rough skin was affected in the order : salinity (EC) > NO3-N > K > Na. Soilchemical components appear to be related to occurrence of physiological disorder, particularly in salinity (EC) and NO3-N.The salinity (EC) and NO3-N were negative related to plant growth. In addition, exchangeable cation capacity play criticalroles in attributing to complex occurrence of physiological disorder.
        136.
        2009.12 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to identify soil physical characteristics as guideline for high yield potential inginseng cultivated field which produced 6 years root. Harvest yields of ginseng to be divided by parent rock was in order ofphyllite and red shale 3.1㎏/3.3㎡ > granite and gneiss·schist 3.0㎏ > basalt 2.6㎏ > porphyry 2.2㎏ in upland and forestsoil. Also, with classified by topography, it was in order of foot slope and alluvial fan 3.2㎏/3.3㎡ > valley 3.0㎏ > low hill2.9㎏ > hill, lave flow and dilluvial terrace 2.8㎏ in survey tilth. Class determination of soil texture, it was in order of sandyloam 3.1㎏/3.3㎡ > loam and silt loam 3.0㎏ > clay loam 2.9㎏ > silt clay loam 2.8㎏ in survey tilth. Slope condition offarming land, in case of sloping (2~7%), it was 3.1㎏/3.3㎡ but deep sloping (15~30%) caused decreasing harvest yield. Indrainage classes (excessively, well and moderately well), there was no significantly different in harvest yields. Relationshipbetween harvest yield and soil series, Production sites as yielding 3.0㎏/3.3㎡ were seven sites, also it was contained 14 soilseries. Production sites as yielding 2.5~3.0㎏/3.3㎡ were eleven sites, it was contained 16 soil series. Production sites asyielding 2.0~2.5㎏/3.3㎡ were 10 sites, it was contained 4 soil series.
        137.
        2009.10 KCI 등재 서비스 종료(열람 제한)
        To study the optimal cultivation for paddy soil, growth characteristics and ginsenoside content was investigated by both of poor drainage class (PDC) and imperfect drainage class (IDC) in three-year-old ginseng of varieties, Cheonpoong (CP), Yeonpoong (YP), Hwangsookjong (HS), and Jakyeongjong (JK). Root yield of IDC was higher than that of PDC by 3.6 times because stem length, leaf area, and chlorophyll contents were increased, while discolored leaf ratio was decreased. Root yield of HS in PDC was highest among four varieties because chlorophyll contents, leaf area, and survived plant ratio were relatively high. Root yield of CP in IDC was highest among four varieties because of high leaf area and survived plant ratio, and low discolored leaf ratio. Ratio of rusty-colored root showed significant difference by varieties, which was the highest in HS and the lowest in CP among four varieties irrespective of drainage classes. Total ginsenoside contents showed significant difference by drainage classes, which were high in IDC of good growth and low in PDC of poor growth. Total ginsenoside contents were high in JK and CP, while low in HS and YP both of drainage classes.
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