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        검색결과 24

        1.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to develop an optimal greenhouse model for strawberry seedling during the summer high-temperature period based on the results of field surveys. We conducted a survey on the structure types of 46 strawberry seedling farms nationwide, including width, ridge height, eaves height, ventilation method, seedling bed width, and spacing. Based on the survey results, we derived the optimal greenhouse model by considering various factors. The greenhouse width was set at 14 meters to maximize the efficiency of seedling beds and overall space. The height was determined at 2 meters, taking into account ventilation during the summer season. To reduce stress on the supporting structure due to snow loads, we established a reinforcement installation angle of 50 degrees. We analyzed two different models that use support beams with dimensions of φ48.1×2.1t and φ59.9×3.2t, respectively, to ensure structural safety against meteorological disasters, considering regional design wind speeds and snow accumulation. We utilized these developed greenhouse model to conduct strawberry seedling experiments, resulting in a high survival rate of average 93.2%. These findings confirm the usefulness of the strawberry seedling greenhouse in improving the seedling environment and enhancing overall efficiency.
        4,000원
        2.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was aimed to isolate bacterial inoculants producing chitinase and evaluate their application effects on corn silage. Four corn silages were collected from four beef cattle farms to serve as the sources of bacterial inoculants. All isolates were tested against Fusarium graminearum head blight fungus MHGNU F132 to confirm their antifungal effects. The enzyme activities (carboxylesterase and chitinase) were also measured to isolate the bacterial inoculant. Based on the activities of anti-head blight fungus, carboxylesterase, and chitinase, L. buchneri L11-1 and L. paracasei L9-3 were subjected to silage production. Corn forage (cv. Gwangpyeongok) was ensiled into a 10 L mini silo (5 kg) in quadruplication for 90 days. A 2 × 2 factorial design consists of F. graminearum contamination at 1.0104 cfu/g (UCT (no contamination) vs. CT (contamination)) and inoculant application at 2.1 × 105 cfu/g (CON (no inoculant) vs. INO (inoculant)) used in this study. After 90 days of ensiling, the contents of CP, NDF, and ADF increased (p<0.05) by F. graminearum contamination, while IVDMD, acetate, and aerobic stability decreased (p<0.05). Meanwhile, aerobic stability decreased (p<0.05) by inoculant application. There were interaction effects (p<0.05) on IVNDFD, NH3-N, LAB, and yeast, which were highest in UCT-INO, UCT-CON, CT-INO, and CT-CON & INO, respectively. In conclusion, this study found that mold contamination could negatively impact silage quality, but isolated inoculants had limited effects on IVNDFD and yeast.
        4,000원
        3.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 연동온실의 골조로 인한 내부 광 분포를 검토 하기 위하여 위치별(중앙부 및 측면부) 일사량을 실측하고, 오 전(08:30-12:30)과 오후(12:35-16:30)로 시간대를 구분 하여 일사량, 광 투과율 및 일 적산일사량을 분석하였다. 또한 토마토의 생육 및 수확량을 위치별로 비교하였다. 오전일 때 중앙부와 측면부의 일사량은 각각 275.2W·m-2, 314.9W·m-2 이고, 오후일 때는 각각 278.1W·m-2, 313.9W·m-2로 측면부 보다 중앙부가 오전은 12.6%, 오후는 11.4% 낮았고, 광 투과 율과 일 적산일사량도 중앙부가 낮게 나타났다. 생육 특성에 있어서는 첫 번째 조사의 엽장과 엽폭을 제외하고는 조사 종 료일까지 유의미한 차이가 없었다. 토마토의 최종 주당 평균 수확량은 재배 위치에 따라 중앙부 4,828g, 측면부 4,851g으 로 유의미한 차이는 없었고, 중앙부가 0.5% 적게 나타났다. 토 마토의 광보상점은 60W·m-2이고 광포화점은 281W·m-2로 중앙부의 시간대별 일사량은 광보상점보다는 높고, 광포화점 보다는 낮으나 그 차이가 크지 않아 온실 내 위치에 따른 생육 및 수확량의 차이가 미미한 것으로 판단하였다. 향후 이 검토 결과를 포함하여 온실을 설계할 때 광 환경을 고려한 설계를위해 온실의 설치 방향, 위치 및 지붕 경사도 등에 따른 온실 내 광 분포 분석이 필요하다.
        4,000원
        4.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 실대형 실험과 구조해석을 통해서 현장에서 사용되는 가새 시스템을 적용한 강관 골조 플라스틱 연동온실 의 횡하중 가력시험을 수행하고 성능을 분석하였다. 횡강성 과 응력을 분석하기 위해 실험체에 변위와 변형률계를 각각 9 개소 및 16개소 설치하였으며 가새의 설치 유무에 따른 성능 을 비교하기 위해 구조해석을 수행하였다. 실대형 실험과 가 새의 설치 유무에 따른 구조해석 결과 비교에서 구조물의 횡 강성이 많은 차이를 보였다. 실험체의 측고 부근에서 측정한 횡강성은 가새 시스템을 설치함으로 강성을 최대 44%까지 증 가시켰다. 현장에서 사용하는 가새의 접합부가 충분한 강성 을 확보하지 못함으로써 외력을 전체 구조물에 적절히 전달하 지 못하여 횡강성이 구조해석 결과보다 많이 저하되는 현상이 나타났다. 따라서 온실 설계 시 구조성능의 신뢰성을 높이기 위해서 가새 시스템의 연결방법, 설치위치, 부재의 최대길이 등 온실의 접합부에 대한 명확한 시공방법과 설계기준이 정립 되어 온실 설계가 이루어져야 할 것으로 판단된다.
        4,000원
        5.
        2022.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        연구는 참외 재배 지에서 흰가루병, 담배가루이 및 두점박이응애가 동시에 발생하였을 때 45, 40, 35°C (대조구)의 온도에서 측창으로 환기 처리 시, 온실 내 온 ․ 습도의 변화, 병충해 발생과 잎말림, 그리고 개화조절에 미 치는 효과를 검토하였다. 3월 3일 ‘히든파워’ 대목에 접붙여진 ‘알찬꿀’ 참외를 40cm 간격으로 격리상에 심었고, 위 에 언급한 병해충이 모든 처리구에서 발생한 6월 18일부터 7월 13일까지 처리하였다. 온실의 온도는 맑은 날에는 설정 온도 지점까지 증가되었고, 45°C 환기 처리에서 고온 고습이 약 9시간 동안 유지되었다. 주간 최고 기온과 최 저 상대습도 차이는 45°C 환기 처리에서 가장 높았다. 환기 처리 11일 후에는 흰가루병과 두점박이응애 피해가 45°C 환기 처리에서 거의 회복되었지만 40°C와 35°C에서는 그렇지 않았다. 처리 14일 후, 담배가루이와 두점박이 응애 밀도는 45°C에서 유의하게 감소하였으나 흰가루병 증상은 유의하게 감소하지는 않았다. 잎말림은 고온에서 유발되었으나 45°C에서도 심하지 않았다. 처리 26일 후, 새로 나온 줄기의 15 마디의 개화수를 조사한 결과, 45°C에 서 암꽃이 전혀 나오지 않았고 수꽃은 1.2개로 나타났다. 이상의 결과는, 고온기에 45°C의 고온에서 2-3주간 환기 처리는 온실 내부의 고온 고습을 유도하여 흰가루병, 담배가루이, 두점박이응애를 통제하고, 개화를 억제하여 참외 의 영양 생장을 회복할 수 있는 방법으로 사료되었다.
        4,000원
        6.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 원예특작시설 내재해형 규격서에 등록되어 있는 폭이 넓은 단동온실(10-단동-5형)을 대상으로 기초의 경계조건과 서까래 강관의 이음 유무에 대해 실물 크기 실험을 실시하고 그 결과를 수치해석 결과와 비교하여 이음부가 있을 때 구조성능 차이에 대해 알아보았다. 각 측정 위치별 변위를 실험에서 측정한 값과 수치해석으로 예측한 값을 비교한 결과에서는 기초의 조건 및 서까래 강관 이음 유무에 상관없이 모두 상당한 차이를 보였고, 힌지 조건 보다 고정 조건이 상대적으로 차이가 컸다. 그리고 모든 절점을 강접합으로 가정하고 구조해석한 결과를 구조실험과 비교한 결과에서는 힌지조건이 고정조건 보다 잘 일치하였지만 해석값이 실험값 보다 크게 나타났다. 수치해석은 모든 절점을 강접합으로 가정했기 때문에 실제 성능과 달랐다. 따라서 현재 모든 절점을 강접합 으로 가정하고 온실을 설계를 하면 과소설계될 우려가 있어 앞으로 신뢰성 높은 온실 설계를 위해서는 서까래와 도리가 교차하는 교차부 성능 특성을 고려한 구조해석 기술 개발이 이루어져야 할 것으로 판단된다.
        4,000원
        8.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 중소기업의 임원보수, 기업성과, 국제화에 대한 소유구조의 역할을 고찰한다. 소유와 경영의 엄격한 분리를 상정한 기존 문헌과 달리 소유와 경영이 중첩되는 임원의 주식소유에 주목한다. 임원 소유지분을 지배주주 소유지분과 분리․취급함으로써 임원보수, 기업성과, 국제화에 미치는 소유지분의 순효과를 임원과 지배주주의 몫으로 분해하여 측정할 수 있다. 이에 2014~2018년 기간 비금융산업에 속하는 국내 상장 중소기업의 공시정보를 활용하여 소유지분 및 임원보수가 기업성과와 국제화에 각각 어떠한 효과를 가져오는지를 주로 분석하였다. 주요 분석 결과는 다음과 같다: (1) 임원보수는 기업성과와 국제화에 직접 영향을 미치는 요인이며, (2) 임원 지분소유는 임 원보수와 양의 상관관계를 통해 간접 경로로 기업성과와 국제화에 영향을 주고 있으나, (3) 지배주주 지분소유은 기업성과 및 국제화에 직․간접 관계가 있다고 판단하기 어렵다. 이 결과를 통해 소 유와 경영의 일치가 기업성과와 국제화에 직․간접적으로 중요한 요소라는 점을 확인할 수 있다.
        6,700원
        9.
        2017.10 구독 인증기관·개인회원 무료
        An increased use of organic phosphorous based chemical pesticides in domestic and overseas agriculture has resultedin emergence of tolerant strains of insect pests. These pests have spread throughout South Korea and are responsible forsignificant reduction in crop yields. Furthermore, as yet there is no effective way of controlling these insects or the damageresulting from pest infestation. To this end, we are attempting to develop biological control based methods to protectcrop plants against insect pests. A screen for biocontrol agents conducted in five farms that were heavily infested bynematodes in 2015-2016 identified Aspergillus niger F22 strain that was very effective against root-knot nematode. Afour-time treatment with A. niger F22 at an internal of ten days was able to reduce nematode population by 70-90%compared to untreated controls. The biocontrol agent was also more effective compared to ograno-phosphorus based pesticide,which caused a 30% reduction in nematode population. Notably, the extract (suspension concentrate) prepared from A.niger culture was equally effective in controlling the root-knot nematode and is currently being developed as a marketableproduct under the brand name “NAMAFREE”.
        10.
        2017.10 구독 인증기관·개인회원 무료
        Oyster mushrooms are one of the most famous mushrooms for foods in Korea. ‘Santari’ developed on this study is P. pulmonarius of oyster mushroom species. ‘Santari’ is a new variety of oyster mushroom for the bottle culture. It was bred by mating with monokaryons isolated from ‘GMPO20404’ and ‘Hosan’. The optimum temperature for the mycelial growth was 26~29°C on PDA medium and that for the primordia formation and the growth of fruiting body of ‘Santari’ was 22°C and 20°C on sawdust media. It took 34 days to finish spawn running, 3 days to finish primordia formation, 3 days to finish fruitbody growth in the bottle culture. In the characteristics of fruit body, pilei were round type and brownish, stipe color was white and stipe shape was long and thick. The yield per bottle was 172g/1,100ml and was 43% higher than that of control variety(Hosan). As results of the physical properties of fruit body, springness, cohesive, gumminess and brittleness of stipe tissue were 87%, 82%, 193g and 16kg, respectively. The values of them are lower than those of control except cohesive.
        11.
        2017.10 구독 인증기관·개인회원 무료
        Oyster mushrooms are one of the most famous mushrooms for foods in Korea. ‘Santari’ developed on this study is P. pulmonarius of oyster mushroom species. ‘Santari’ is a new variety of oyster mushroom for the bottle culture. It was bred by mating with monokaryons isolated from ‘GMPO20404’ and ‘Hosan’. The optimum temperature for the mycelial growth was 26~29°C on PDA medium and that for the primordia formation and the growth of fruiting body of ‘Santari’ was 22°C and 20°C on sawdust media. It took 34 days to finish spawn running, 3 days to finish primordia formation, 3 days to finish fruitbody growth in the bottle culture. In the characteristics of fruit body, pilei were round type and brownish, stipe color was white and stipe shape was long and thick. The yield per bottle was 172g/1,100ml and was 43% higher than that of control variety (Hosan). As results of the physical properties of fruit body, springness, cohesive, gumminess and brittleness of stipe tissue were 87%, 82%, 193g and 16kg, respectively. The values of them are lower than those of control except cohesive.
        12.
        2016.06 구독 인증기관·개인회원 무료
        ‘Mantari’ is a new variety of oyster mushroom for the bottle culture. It was bred by mating with monokaryons isolated from ‘DM11732’ and ‘Chunchu-2ho’. The optimum temperature for the mycelial growth was 26~29°C on PDA medium and that for the primordia formation and the growth of fruiting body of ‘Mantari’ was 18°C and 16°C on sawdust media. It took 32 days to finish spawn running, 4 days to finish primordia formation, 3 days to finish fruitbody growth in the bottle culture. In the characteristics of fruit body, pilei were round type and dark grayish, stipe color was gray-white color and stipe shape was long and thin. The yield per bottle was 179g/900ml and was 5% higher than that of control veriety(Chunchu-2ho). As results of the physical properties of fruit body, springness, cohesive, gumminess and brittleness of stipe tissue were 96%, 76%, 160g and 15kg, respectively.
        14.
        2004.12 구독 인증기관 무료, 개인회원 유료
        Human embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo. Human ES cells have the capacity to differentiate into various types of cells in the body. Human ES cells are indefinite source of cells for cell therapy in various degenerative disorders including neuronal disorders. Directed differentiation of human ES cells is a prerequisite for their clinical application. The objective of this study is to develop the culture condition for the derivation of neural precursor cells from human ES cells. Neural precursor cells were derived from human ES cells in a stepwise culture condition. Neural precursor cells in the form of neural rosette structures developed into neurospheres when cultured in suspension. Suspension culture of neurospheres has been maintained over 4 months. Expressions of nestin, soxl, sox2, pax3 and pax6 transcripts were upregulated during differentiation into neural precursor cells by RT-PCR analysis. In contrast, expression of oct4 was dramatically downregulated in neural precursor cells. Immunocytochemical analyses of neural precursor cells demonstrated expression of nestin and SOX1. When induced to differentiate on an adhesive substrate, neuro-spheres were able to differentiate into three lineages of neural systems, including neurons, astrocytes and oligo-dendrocytes. Transcripts of sox1 and pax6 were downregulated during differentiation of neural precursor cells into neurons. In contrast, expression of map2ab was elevated in the differentiated cells, relative to those in neural precursor cells. Neurons derived from neural precursor cells expressed NCAM, Tuj1, MAP2ab, NeuN and NF200 in immunocytochemical analyses. Presence of astrocytes was confirmed by expression of GFAP immuno-cytochemically. Oligodendrocytes were also observed by positive immuno-reactivities against oligodendrocyte marker O1. Results of this study demonstrate that a stepwise culture condition is developed for the derivation of neural precursor cells from human ES cells.
        4,000원
        15.
        2015.06 서비스 종료(열람 제한)
        Diffuse involvement of the right pulmonary artery (PA) associated with fistula between the PA and coronary artery is report-ed in a woman with Takayasu’s arteritis. Both the subclavian arteries were totally occluded and drained by the meanderinged artery arising from both common carotid arteries. Lung perfusion scan revealed perfusion defect of right lung. Two fistulas were identified. A large fistula was between the right PA and left circumflex artery. A small fistula was between the right PA and left anterior descending artery. This is a rare case of Takayasu’s arteritis presenting with a coronary – pulmonary artery fistula that is secondary to a diffuse unilateral involvement of PA.
        16.
        2013.07 서비스 종료(열람 제한)
        MicroRNAs (miRNAs) are a class of non-coding RNAs of approximately 21-nt which play important roles in regulating gene expression in plants. Although many miRNA studies have focused on a few model plants, the miRNAs and their target genes remain largely unknown in pepper, one of the most important crops cultivated worldwide. Here we employed high-throughput small RNA sequencing to extensively identify miRNAs in pepper from 10 different libraries, including leaf, stem, root, flower, and six developmental stage fruits. Based on bioinformatics pipeline, we successfully identified 29 and 35 families of conserved and novel miRNAs, respectively. We noticed that some miRNAs, whose targets were validated experimentally in this study, exhibited prominent changes in expression levels during fruit development stages. From the qRT-PCR analysis of the target mRNAs, including the SBP-transcription factor and F-box protein, we found that expression of these two target mRNAs gradually decreased in general during fruit development and was negatively correlated with the expression of their corresponding miRNAs. The validation of miRNA-directed cleavage of these target mRNAs, combined with the results of qRT-PCR analysis, likely suggests that some miRNAs in pepper may play a role in fruit development. Conclusively, our study first utilizes high-throughput sequencing to identify and characterize conserved and novel miRNAs and their targets in pepper, providing a basis for understanding the functional roles of miRNAs in pepper.
        20.
        2003.03 KCI 등재 서비스 종료(열람 제한)
        In spite water direct seeding cultivation of rice has advantages in terms of laborsaving and cost-down, it demonstrates uneven seedling establishment and difficult weed management. To select an applicable mat for mulching system of water seeded rice, weed occurrence, growth and yield performances of rice, and soil temperature were evaluated in several kinds of biodegradable mulching material. Field studies were conducted at the experimental farm of National Crop Experiment Station in 1999 and 2000. Among the mats tested in 1999, Safer-mat had the greatest effect on inhibiting weed occurrence and Lawn-mat demonstrated the least efficacy of weed control (EWC) value. In Safer-mat treatment, Ludwigia prostrata was the dominant weed species but Echinochloa crus-galli was not observed. Different kinds of mulching material from the mats studied in 1999 were tested in 2000. Biodegradable polyester (PES) coated on the recycled paper for newspaper press (RP) treatments showed similar or higher EWC values than non-mulched broadcast seed rice with 2 times of herbicide application (BC-herbicide) and Safer-mat that was the most effective mat on preventing weed appearance in 1999. Immediately after mat mulching on the surface of paddy soil, five pregerminated rice seeds were manually sown in each 3cm-hole formerly punctured at 30~times 14 cm spacing in 2000. All the 3 kinds of mulching material tested in 2000 had better seedling stand than BC-herbicide treatment. Rice yield in PES coated with 10 thickness on RP (PES10 ~mu~textrmm +RP) was a little higher than in BC-herbicide treatment but the former produced less panicles in unit land area than the latter. PES10 ~mu~textrmm +RP demonstrated a great effect on raising soil surface temperature than non-mulching treatment throughout the period of seedling establishment.
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