Arctic soils contain a large fraction of our planets terrestrial carbon (C) pool. When tundra soils become warmer and permafrost thaws, non-native geoengineering earthworms can enter these soils and ingest organic matter accumulated over long timescales. Previous studies have found that earthworms increase mineralization rates of soil organic matter into carbon dioxide (CO2) when introduced. Yet, this initial mineralization boost seems transient with time and it has been hypothesized that earthworms stimulate the formation of persistent C forms. In this study, I investigated how non-native, geoengineering earthworms affected the relative proportions of seven carbon forms in the O and A1 horizon of tundra soil and if their effect induced a change in pH. I used Nuclear Magnetic Resonance (NMR) spectroscopy to understand what happens to soil carbon compounds in two different tundra vegetation types (heath and meadow), that had been subjected to earthworm treatment for three summers. I found that O-aromatic C increased from 7.22% ± 0.24 (mean ± stderr) in the meadow soil lacking earthworms to 8.98% ± 0.30 in the meadow exposed to earthworms, and that aromatic C increased from 8.71% ± 0.23 to 9.93% ± 0.25. In similar, the result suggested that alkyl C decreased in this vegetation type from 20.43% ± 0.38 to 18.70% ± 0.25 due to earthworm activities. I found no effect on the chemical properties in the heath. I conclude that geoengineering earthworms affect the two vegetation types differently and that earthworms seem to enhance the accumulation of recalcitrant aromatic C forms.

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京都大学 / 新制・課程博士 / 博士(農学) / 甲第23522号 / 農博第2469号 / 新制||農||1087(附属図書館) / 学位論文||R3||N5353(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 小杉 緑子, 教授 北山 兼弘, 教授 柴田 昌三 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23432号 / 工博第4887号 / 新制||工||1764(附属図書館) / 京都大学大学院工学研究科合成・生物化学専攻 / (主査)教授 杉野目 道紀, 教授 村上 正浩, 教授 大江 浩一 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

No description available.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23216号 / 工博第4860号 / 新制||工||1759(附属図書館) / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 阿部 竜, 教授 陰山 洋, 教授 藤田 晃司 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

No description available.

A turbulence model was developed for computing surface velocity coefficients and discharge under steady, uniform flow conditions for rectangular and compound open-channel cross sections. Reynolds-Average Navier-Stokes (RANS) equations, Reynolds stress equations, and kinetic energy and dissipation equations were applied in the model using the finite-volume method with the SIMPLER algorithm. The models show graphical results of the velocity distributions in the longitudinal bed slope direction, secondary velocities, pressure, turbulence kinetic energy, and kinetic energy dissipation rate across the cross section. Also, the surface velocity coefficients were computed at increments of one-eighth of the base width from the vertical walls to the center of the cross section, and the submergence depth of the floating object from zero to 30 cm, with a 5-cm depth increment. Four different sets of Reynolds stress equations (one set by Boussinesq hypothesis and three sets of algebraic stress model) were used to calculate the results. Only one version of the algebraic stress model was successful in predicting the depression of the maximum streamwise velocity below the water surface. The model was calibrated and verified using laboratory data collected at Utah State University. Calculated discharges from the turbulence model had very good agreement with the laboratory data. The surface velocity coefficients from model results were generally lower than the results from the laboratory data, but higher than the values published by the United States Bureau of Reclamation. Standard cross sections of rectangular and compound cross sections were defined to simulate the model results and model sensitivity to parameter changes. The model results were summarized to show the relationship between surface velocity coefficient and channel characteristics compared with the published values by the USBR. For rectangular cross sections, the coefficients from the model are higher than the published USBR values. But the coefficients from the model and USBR are in very close agreement for the tested compound cross sections. The published coefficients by the USBR are a function of only average water depth. However, the model results show that the coefficients are also related to channel size, surface roughness height, float submergence depth, and lateral location of the float object. These factors should be included in the determination of the surface velocity coefficient to improve the discharge estimations from the application of the float method.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18094号 / 理博第3972号 / 新制||理||1573(附属図書館) / 30952 / 京都大学大学院理学研究科化学専攻 / (主査)教授 丸岡 啓二, 教授 時任 宣博, 教授 大須賀 篤弘 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(情報学) / 甲第18405号 / 情博第520号 / 新制||情||92(附属図書館) / 31263 / 京都大学大学院情報学研究科知能情報学専攻 / (主査)教授 阿久津 達也, 教授 山本 章博, 教授 永持 仁 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM