164 research outputs found

    Linear Macropore Installation to Reduce Red-Soil Erosion in Sugarcane Fields

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    This study determines the cause of soil erosion in red soils in sugarcane fields, especially even with the use of subsoiling fissures, and to compare the effectiveness of a novel artificial linear-macropore with the insertion of fibrous material into the fractures. Four column treatments (tillage, subsoiling, linear-macropore with plant residue fillings, and no-tillage-with-mulching) were established. A subsoiler was used to break up hard soil layers to enhance infiltration, whereas mulching reduced the impact of raindrops on the soil. Sugarcane residue was inserted in the empty fissure to reinforce the structure, making linear macropore. Simulated rainfall with 20 mmh−1 was applied to the soil surface for 6 h per day for two days. Surface runoff, soil erosion, and drainage were measured during each run. Erosion was minimal (1/7 reduction), and bottom drainage was observed in the linear-macropore and no-tillage-with-mulching plots. Conversely, due to the formation of an impermeable layer or surface crust, high erosion (0.282 t-C ha−1 yr−1) and decreased drainage levels were detected in the subsoiling and tillage plots. Moreover, the aboveground protrusion of fibrous material at the linear-macropore maintained infiltration, even following crust formation. Field application of these four management strategies revealed the effectiveness of linear-macropore and mulching in reducing surface flow. Linear-macropore application maintains appropriate levels of infiltration, and insertion of plant residue fillings reinforces the macropore structure while also avoiding clogging. Hence, the linear-macropore scheme may represent an effective strategy for reducing surface runoff and red soil erosion

    Verification of scenario for substorm ignition in the M-I coupling region

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    第2回極域科学シンポジウム/第35回極域宙空圏シンポジウム 11月16日(水) 統計数理研究所 セミナー室

    A case of pulmonary stenosis after a repair for tetralogy of Fallot treated with percutaneous pulmonary valvuloplasty using a triple-balloon technique

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    SummaryThe patient was a 37-year-old female who had undergone a repair for tetralogy of Fallot (TOF) at the age of 4 years. Postoperative pulmonary stenosis remained, but she continued to be managed medically. Approximately 3 years ago, at the age of 34, she exhibited a worsening of fatigue and dyspnea during exertion (New York Heart Association III), and was therefore hospitalized for a detailed examination. In cardiac catheterization, a right ventricle to pulmonary artery peak-to-peak gradient of about 90mmHg was observed. Since it appeared that medical treatment alone would not sufficiently control her heart failure, pulmonary valvuloplasty using a triple-balloon technique was performed for the pulmonary stenosis. The peak-to-peak gradient immediately after the procedure decreased to 13mmHg. There were no indications of restenosis approximately 6 months after the procedure, and the symptoms of heart failure in her daily life improved thereafter
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