• Asian-Australasian Journal of Animal Sciences
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• 제10권3호
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• pp.265-273
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• 1997

The minimum amounts of leucaena (Leucaena leucocephala) required to improve the performance of cattle on a straw diet has been studied. Four levels of leucaena, namely 0 (0%), 2 kg (10%), 4 kg (18%) and 6 kg (27% of dietary dry matter intake) were supplied to 4 adult indigenous bulls ($355{\pm}21.5kg$ weight) fed rice straw alone, in a $4{\times}4$ latin square design. Measurements were made on intake, digestibility, N balance and microbial N yield. Up to 10% level of leucaena supplementation, there were no significant improvement on intake, digestibility, microbial N yield and N balance. Both straw and total dry matter intake showed diminishing return to increasing levels of leucaena supplementation and the maximum intake was observed at around 20% level. However, dietary N and digestible organic matter intake, the microbial N yield and the N balance increased linearly to the increasing levels of leucaena supplementation. On a rice straw based diet, the minimum level of leucaena required to improve the animal performance would probably be at around 20% of the dietary intake.

• 한국조경학회지
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• 제27권2호
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• pp.1-8
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• 1999

This study was carried out to develop new cultivars of Z. serrata showing red fall leaf as street trees. Z. serrata which had red fall leaves were selected and then examined for contents of leaf anthocyanin and chlorophyll. In addition, for the progeny test, selected trees were grafted. Of 21 trees having red autumn leaves, three individuals, 'S-6', 'S-20', and 'I-24' were finally selected. They contained higher level of anthocyanin in the leaves. Once developed, the red color remained till late autumn. Grafted plants of the selected strains showed high grafting efficiency and red foliage color in autumn. The soil pH of the survey sites ranged from 5.9 to 7.24. However, other soil characteristics did not show much difference among the sites with regard to inorganic nutrients including N(%), $P_2O_5$, CEC(mg/meq), $K^+$, $Ca^{3+}$, and $Mg^{2+}$, 'S-6', 'S-20', and 'I-24', clonal lines with red fall leaf were selected as new cultivars and propagates by grafting.

• 한국환경복원기술학회지
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• 제12권6호
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• pp.143-152
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• 2009

This study has been carried out to estimate carbon contents in an average 37-years-old Pinus densiflora plantations and an average 42-years-old natural Quercus acutissima stands in Gongju, Chungnam Province. Average carbon concentration in stemwood, stembark, branch, foliage, and root were 54.59% in Pinus densiflora and 53.73% in Quercus acutissima stands. Aboveground carbon contents was estimated by the equation model logWt = A + BlogD where Wt is oven-dry weight in kg and D is DBH in cm. Total carbon contents was 79.28t/ha in Pinus densiflora stands and 71.52t/ha in Quercus acutissima stands. Net primary carbon production was estimated at 9.79tC/ha/yr in Pinus densiflora stands and 5.52tC/ha/yr in Quercus acutissima stands.

• 한국전자파학회논문지
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• 제26권6호
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• pp.546-554
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• 2015

초 광대역 레이더는 숨겨진 물체를 찾는데 많은 장점을 가지고 있기 때문에, 지표 투과 레이더나 수풀 투과 레이더와 같은 투과레이더에 널리 이용되고 있다. 초 광대역 레이더의 종류 중에 하나인 잡음 레이더는 간섭 환경에 강한 특성을 가지고 있다. 그러나 일반적인 잡음레이더는 고속의 아날로그 디지털 변환기가 필요하여 광대역 레이더로 제작하는데 어려움이 있다. 본 논문에서는 간섭에 강한 특징을 가지면서 고속의 아날로그 디지털 변환기가 필요하지 않은 가상 잡음 레이더 시스템이 연구되었다. 또한, 초 광대역 시스템이 저주파에서 구현되었고, 이는 실험으로 성능이 검증되었으며, 제안된 가상잡음 레이더 시스템의 개념도 증명되었다.

• Journal of Plant Biology
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• 제17권2호
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• pp.87-94
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• 1974

This survey has been carried out on ten species(Erythronium japonicum, Symplocarpus renifolius, Adonis amurensis var. ramosa, Corydalis turtschaninovii var. genuina, Primula sieboldii forma spontanea, Anemone raddeana, Gagea Iutea, Heloniopsis japonjca, Hylomecon japonicum, and Convallaria majalis var. keiskei in the undergrowth of a forest of deciduous broad-leaved trees in the Kwangnung area of Kyung-Ki Province. They always bloom towards the end of March which is earlier than most of the other plants do. They completely finish up their matter productions before foliage of the deciduous trees, which are the upper strata plants, grows broader or to cite in other terms, before the relative light intensity in the lower strata is fallen to the lowest degree to become to insufficient to allow for photosynthesis. These phanerophytes naturally wither down between June and July. The above mentioned phenomenon clearly demonstrates a kind of the ecological niches and habitat segregation in terms of using sunlight to her greatest advantage. Soon after these herbs wither they make their own winter buds-life form-around their roots and then go into hibernation. The intensity of light in this forest zone was measured through the use of a lux meter in order to investigate it's seasonal variations. In additions, an intensive survey on the duration of their efflorescence was fullfilled.

• The Korean Journal of Ecology
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• 제21권5_3호
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• pp.665-673
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• 1998

This study was conducted to clarified the relationship between bird community and forest structure and present the counterplan for protection and management of bird community from February 1993 to July 1995 at deciduous and coniferous forest within Mt. Nam area, Seoul, Korea. DBH distribution has not significant differences in each study site. Deciduous forest had more foliage coverage in all layers than coniferous forest. Total 41 species of birds, which were 16 species of resident, 14 species of summer visitor, 4 species of winter visitor, and 7 species of passage migrant were recrded in two study sites. Leaf use rate of birds was increased the increase of coverage. The number of breeding species and pairs, breeding density, and diversity index were greater in deciduous forest than coniferous forest. The number of species and pairs on bush-nesting and foraging guild were greater than other guilds. And the nuber of species and pairs on hole nesting guild were the fewest in nesting guild. Use rate of artificial nests for improvement of habitat quality was greater in coniferous forest than deciduous forest. Maintenance of bush layer, increase of coverage and leaf layer diversity, supply of artificial nests, management of large trees, and control of natural enemy were necessary for protection and management of bird community in Mt. nam area.

• 한국환경복원기술학회지
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• 제8권5호
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• pp.1-9
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• 2005

This study was conducted to investigate the effect of aquatic plant as a botanical air purification on the indoor air pollution by formaldehyde. Three aquatic plants such as Eichhornia crassipes, Cyperus alternifolius, Echinodorus cordifolius, were selected for this study and they were placed in the artificially contaminated chamber under laboratory condition. The results showed that all three plants could remove the formaldehyde from the contaminated air system effectively. Reduction in the formaldehyde levels by Eichhornia crassipes, which is the floating plant, might be associated with the factors of plant and water. Reduction in the formaldehyde levels by Cyperus helferi and Echinodorus cordifolius, which were emergent plant, was due to the complex effect of plant, soil medium and water. In aquatic plant system, dissolution, microbial degradation in rhizosphere, uptake through root and shoot, sorption to soil and shoot, hydrolysis are known as the main mechanisms of water soluble pollutants in the given system. The advantages of indoor air quality control system using aquatic plants can be; 1) various purifying mechanisms than foliage plants, 2) effective for decontamination of water soluble pollutants; 3) easy for maintenance; 4) diverse application potential. Therefore it was suggested from the results that indoor air control system of aquatic plants should be more effective for reduction of indoor air pollutants.

• 식물병연구
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• 제9권1호
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• pp.36-38
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• 2003

2001년 9월 경기도 성남시 분화용 브룬펠지아에서 F. oxysporum에 의한 줄기마름병이 발생하였다. 처음에는 생육이 부진하고 아래 잎부터 누렇게 변색되며, 줄기가 마르고 심한 경우 나무 전체가 말라죽는다. 병든 식물체의 줄기를 잘라보면 줄기 내부의 도관부가 갈색 내지 암갈색으로 변하는 것이 특징이었다. 병원균을 분리하여 형태적·배양적 특징을 조사한 결과 F. oxysporum으로 동정되었으며 병원성 검정 결과 자연상태와 동일한 병징을 확인할 수 있었으므로 이 병을 Fusarium oxysporum에 의한 브룬펠지아 줄기마름병으로 명명할 것을 제안한다.

• Nuclear Engineering and Technology
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• 제15권2호
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• pp.110-116
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• 1983

육상식물인 대두(Glycine max)에 있어서 Sr-90의 흡수 및 이행과정을 온실조건하에서 실험하여 다음과 같은 결과를 얻었다. 엽면처리한 Sr-90은 식물체의 다른 부위로 일부분만이 이행하였고 대부분은 잎에 그대로 잔류하여 낙엽에 의한 토양오염의 원인이 되고 있었다. 토양처리한 Sr-90은 뿌리를 통하여 흡수된 다음 잎, 줄기, 종자, 뿌리등 각 부위로 널리 분포되는데 식물의 생육단계에 따라 그 패턴이 달리 나타났다.

• 한국육종학회지
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• 제42권3호
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• pp.207-211
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• 2010

'Taedong Valley' is a high yielding and processing potato cultivar, which is a clonal selection resulting from a cross between 'W870' and 'A88431-1'. It is a medium maturating cultivar with medium plant height and light green foliage. 'Taedong Valley' has profuse flowering habit and light purple flowers. Tubers are smooth, round, and with yellow skin, light yellow flesh, medium eye depth. Tubers have medium dormancy and good keeping quality. 'Taedong Valley' has stable yield under wide range of climatic conditions. It is resistant to common scab and potato virus Y, but moderately susceptible to late blight. It is also resistant to most of the disorders, particularly dehiscence, hollow heart and internal brown spots. This cultivar has high level of tuber uniformity and capable of yielding 43.6 t/ha which is about 9.0% higher than the control potato cultivar 'Atlantic' under optimum agronomical practices.