• 한국토양비료학회지
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• 제49권5호
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• pp.577-583
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• 2016

Small-sized persimmons produced by high crop load are better accepted in the export markets. However, maintaining high crop load frequently results in weakness of tree vigor, deterioration of fruit quality, and increase of the risks for alternate bearing. This experiment was conducted to determine the combined effects of fertilization rate and leaf-fruit (L/F) ratio on container-grown 3-year-old 'Fuyu' persimmon trees. Application of 3.6-g N, 2.1-g $P_2O_5$, 2.7-g $K_2O$, 2.7-g CaO, and 0.6-g MgO was for the control fertilization rate (CF) and that of a 3-fold CF was for the high fertilization rate (HF). Commercial fertilizers were surface-applied to a container on July 6, July 17, and August 10 in three equal aliquots. Single tree for each fertilization rate was assigned for 12 L/F ratios (5, 6.3, 7.7, 9, 10.4, 13, 15.5, 18, 21, 24, 27, and 33) mostly by fruit thinning or rarely by defoliation on July 1. HF did not affect the yield, weight and soluble solids of the fruits but decreased skin color. As L/F ratio increased, yield decreased but average weight, skin color, and soluble solids of fruits increased. With HF, N and K concentrations in leaves, fruits, and shoots increased to some extent but soluble sugars in dormant shoots decreased. Many shoots were cold-injured with low L/F ratio especially at the HF. HF did not increase number of flower buds the next spring either on a shoot or on a tree basis but increased shoot length, compared with the CF. Increasing L/F ratio markedly increased number of flower buds and shoot growth the following year at both fertilization rates. Therefore, an appropriate combination of fertilization rate and L/F ratio should be necessary to maintain stable fruit production and tree vigor at high crop load.

• Journal of Plant Biotechnology
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• 제43권1호
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• pp.132-137
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• 2016

The genus Cypripedium, known as lady's slipper orchid, has been considered to have a considerable marketability as a potted and garden plant with beautiful flowers; however, this species is becoming endangered and, in some places extinct, due to habitat destruction and illegal collections. As such, an optimized artificial propagation system is necessary for its conservation and horticultural cultivation. For the establishment of the in vitro proliferation of the endangered Cypripedium macranthos Sw., native to Korea, the effects of medium strength and sucrose concentrations on germination, protocorm formation and seedling growth were investigated through asymbiotic seed culture. The highest germination rate and protocorm formation rate were obtained with a 1/4 MS medium; higher MS medium strengths did not generate the favorable conditions required for germination and protocorm growth. The overall growth characteristics of roots and buds developed from protocorms were best in cultures of 1/4 MS medium. On this medium containing $10g{\cdot}L^{-1}$ sucrose, both the germination rate and protocorm formation rate increased significantly. The general growth properties of seedlings developed on the medium with $10g{\cdot}L^{-1}$ sucrose were best, showing the highest bud formation rate and root number. Our results demonstrate that the 1/4 MS medium, supplemented with $10g{\cdot}L^{-1}$ sucrose, could improve in vitro germination, and facilitate the growth of seedlings developed from the protocorms of C. macranthos Sw.

• 한국생물환경조절학회:학술대회논문집
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• 한국생물환경조절학회 2006년도 춘계 학술대회 및 정기총회
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• pp.202-205
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• 2006

• 한국자원식물학회지
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• 제22권6호
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• pp.518-521
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• 2009

High productivity of ginger (Zingiber officinale Roscoe) was obtained from the rhizome produced by shoot-tip culture with Korean native variety, Seosanjong. Seed rhizomes induced by shoot-tip culture were successfully established in the field. The rhizomes induced by both plant or rhizome were higher in emergence rate and faster in days to emergence than those of home seed production. The seed rhizome production induced by shoot-tip culture was two times heavier than that of home seed production. These results suggest that shoot-tip culture might be one of mass propagation methods in seed rhizome of ginger plant.

• 한국토양비료학회지
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• 제51권1호
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• pp.1-7
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• 2018

The veterinary antibiotics treated to livestock have a potential risk to reach to soil and water environment, and eventually be taken up by plants. The objective of the study was to investigate the effect of zeolite and shell meal fertilizer amendment on antibiotic uptake by plant when veterinary antibiotics in chicken manure compost were applied to agricultural land. Model antibiotics used in the study were chlortetracycline (CTC), tylosin (TYL), and sulfamethazine (SMT). Chlortetracycline level in lettuce was decreased to less than $0.08ug\;kg^{-1}$ by application of zeolite as compared with about $0.26ug\;kg^{-1}$ for control without amendment on 33 days after transplanting. Tylosin was not detected for all the treatment. Sulfamethazine levels in lettuce ranged from 11 to $19{\mu}g\;kg^{-1}$ on a fresh weight basis and gradually decreased with time. Zeolite application decreased the SMT levels in lettuce by greater extent than shell meal fertilizer amendments. Results from the 61-d greenhouse experiment imply that application of zeolite at a rate of $1.5Mg\;ha^{-1}$ or shell meal fertilizer at a rate of $2.0Mg\;ha^{-1}$ can reduce CTC and SMT concentration in lettuce cultivated in soil fertilized with antibiotic-contaminated chicken manure compost.

• 한국토양비료학회지
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• 제51권1호
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• pp.8-15
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• 2018

A portion of the veterinary antibiotics administrated to livestock are generally excreted via feces and urine. Tetracyclines and tylosin have a greater priority of environmental risk in Korea based on the consumption and the potential to reach soil and water environment. The antibiotics in animal byproducts need to be reduced or eliminated before they are applied to agricultural lands through composting or other agricultural practices. The objective of the study was to investigate the effect of aeration on degradation of antibiotics during storage of swine slurry. Two antibiotics, tetracycline (TC) and tylosin (TYL), were detected from the swine slurry used in the study. One hour aeration per day for 62 days reduced TC concentration from 199 to $43ng\;L^{-1}$ compared with $104ng\;L^{-1}$ without aeration. Aeration for three and six hours decreased TC level to 30 and $23ng\;L^{-1}$, respectively. The dissipation of TC was fitted with a first-order kinetic model. Aeration for 1, 3, and 6 hours every day increased the first-order rate constant, k, from $0.011day^{-1}$ under anaerobic condition to 0.022, 0.026, and $0.037day^{-1}$, respectively. For TYL, aeration during storage of swine slurry enhanced k from $0.0074day^{-1}$ to 0.014, 0.018, and $0.031day^{-1}$ for 1, 3, and 6 hours per day, respectively. For liquid swine slurry, biotic processes can be more effective for dissipation of antibiotics than abiotic processes because of low organic matter and high water content. These results suggest that aeration can increase the degradation rate of antibiotics during storage of swine slurry.

• 항공우주시스템공학회지
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• 제1권1호
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• pp.45-52
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• 2007

This paper analyzed the extension effects of fatigue life and the application of pre-indentation in aircraft structural material such as aluminum alloys. The test specimen used the thin sheet of aluminum alloy with a single-edged notch. The experiments were conducted after making the pre-crack under a constant amplitude loading. As the fatigue life extension technique, the pre-indentation making an indent on the predicted path of crack propagation was applied. The work presented here discussed about a proper mathematical relation between crack growth rate and the range of stress intensity factor and about the generalization of crack growth mechanism with large retardation effect. A technique to enhance the applicability of pre-indentation if also mentioned.

• 콘크리트학회논문집
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• 제16권4호
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• pp.511-520
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• 2004

이 연구에서는 기존의 콘크리트 실험에서 평가된 파괴에너지를 수정 특이-파괴진행대 이론에 대해 해석하였다. 수정 특이-파괴진행대 이론은 균열성장에 대한 에너지해방률과 균열면의 파괴진행에 대한 균열면응력-균열폭 관계의 두 파괴특성을 필요로 한다. 해석결과 균열면응력-균열폭 관계는 시험편의 형상과 균열속도에 민감하지 않았다. 파괴진행대에서 파괴에너지율은 파괴진행대가 완전히 형성될 때까지 균열성장길이에 선형으로 증가하였으며, 이후에는 파괴에너지밀도로 일정한 값을 유지하였다. 변형에너지방출률은 시험편의 형상과 균열속도에 큰 변화를 보였으며, 균열속도에 대해서는 선형의 대수함수로 표현될 수 있다. 균열성장에 대한 변형에너지방출률의 변화는 다른 실험의 미세균열의 성장과 국부화 그리고 완전 파괴진행대의 형성에 대한 이론적인 근거를 보여준다.

• Journal of Acupuncture Research
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• 제26권4호
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• pp.19-27
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• 2009

Objectives : To investigate the improvement rate of muscle weakness caused by lumbar disc herniation, 17 patients was treated with oriental medicine. Methods : To evaluate weakness of big toe extensor muscles caused by lumbar disc herniation, we measured the active range of motion(ROM) of big toe extension and muscle grading of big toe extensor muscles. We also measured numerical rating scale(NRS), oswestry disability index(ODI) and compared them with the active ROM of big toe extension. Results : 1. Progressive weakness of big toe extensor muscles was observed in 2 patients. Weakness of big toe extensor muscles were improved in 13 patients(76%). 2. Changes in manual muscle testing(MMT) scores corresponded with improvement rate of big toe extension. 3. Numerical rating scale(NRS) and oswestry disability index(ODI) improvement rate did not correspond with improvement rate of big toe extension. Conclusions : Muscle weakness caused by lumbar disc herniation can be treated with oriental medicine and progressive muscle weakness must be observed constantly.

• 대한교통학회지
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• 제23권2호
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• pp.83-92
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• 2005

OECD 국가들 중 국토계수가 우리나라의 50%(1/2)~200%(2배)인 4개국의 1인당 GDP 10,000달러 도달시기의 국토계수당 도로보급률을 비교하면, 우리나라의 유효도록보급률은 평지대비 약 58.9% 수준, 총면적대비 약 63.4% 수준인 것으로 분석되었다. 철도도 동일한 방법으로 우리나라의 철도스톡규모가 이들 국가의 평지 면적 대비 약 41.3%, 전체 면적 대비 약 53.2% 수준으로 분석되었다. 또한 이들 나라의 평균 유효도로연정과 유효철도연장을 목표 도로 및 철도스톡으로 정의하고 목표스톡에 도달하기 위한 각년도 목표주자금액을 산정하였는데, 2000년 실질가격 기준으로 도로와 철도는 매년 약 15조 2천억 원 및 약 6조 5천억 원을 투자하여야 하는 것으로 분석되었다. 이를 실제 투자금액과 비교하면 철도는 실제 투자금액이 목표투자금액에 미달하여 향후 철도투자를 증가시킬 필요성이 제기되었다.