京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20661号 / 医博第4271号 / 新制||医||1024(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 川口 義弥, 教授 柳田 素子, 教授 斎藤 通紀 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

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Encore azaleas are popular ornamental plants for their full sun tolerance, coldhardiness, low maintenance requirements, and reblooming habit in spring, summer, and fall. With their varying growth rates and multiple blooms during a growing season, there is limited information on the nutrient and irrigation requirements of Encore azalea cultivars. The objectives of this study were to investigate the optimum nitrogen (N) requirement of Encore azalea ‘Chiffon’ during a growing season and determine how irrigation frequency and fertilization practices (rates, methods, and timing) affect plant growth and nutrient uptake using both a traditional plastic container and a paper biocontainer. One-year-old liners of Encore azalea ‘Chiffon’ were treated with different N fertigation rates, irrigation frequencies, and sprayed with 3% urea or water in late fall. Plants were investigated for their growth responses and flower production, and analyzed for nutrient and carbohydrate status in different studies when they were grown in both a traditional plastic container and a biodegradable container made from a mix of recycled paper. The biocontainers increased plant growth index, plant dry weight, leaf area, root growth, and uptake of both macro- and micronutrients using N rates of 10, 15, and 20 mM. During a growing season, the biocontainer-grown plants had three flushes of growth while the plastic container-grown plants had only two. The third flush of growth on the biocontainer-grown plants occurred in mid-September, resulting in greater dry weight and N uptake than with plants grown in plastic containers. One irrigation per day resulted in higher flower count and greater root length and surface area. Foliar urea application in late fall was effective in improving plant N status by increasing plant N concentration and content without affecting plant dry weight, but decreased tissue concentrations of glucose, fructose, sucrose, and starch to varying degrees.

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In the time line of world industrial age, the most important era begins in the late 18th century when the use of fossil fuels was growing intensively. This approach has continued and developed up to the 20th century. Besides, this trend has had side effects like polluting environment. Air pollution is one of the critical issues nowadays that stems from using hydrocarbon fuels. One type of the problematic compounds in polluting air is nitrogen oxides that can be produced in combustion process from engines and industrial plants. Different solutions have been suggested to remove air polluting compounds. One method for removing nitrogen oxides is using the mechanism of Selective Catalytic Reduction in silencer of engines. This method has become practical in trucks’ engines. Therefore, research on SCR chemistry is important for improving the usage of this method in removing nitrogen oxides. SCR has its own problems when used in trucks. One of the problems is formation of white clumps on pipe wall of silencers using SCR which can cause back pressure in the engines and costs a lot to remove them from engines.  This report evaluates the effect of alternative fuels on SCR chemistry .Different parameters affecting deposit formation are studied and evaluated. Ethanol is one of the controversial fuels used in engines and acetic acid is one its byproducts. Also, urea and its by products are important materials in SCR chemistry, too. Consequently, the first part of the report studies the influence of acetic acid and Ferrite steel, one of the usual steels in silencers of engines, on urea, biuret and cyanuric acid decomposition. The instruments used in the first part include TGA-DSC (Thermo Gravimetric Analysis-Differential Scanning Calorimetric) which is connected to FTIR (Fourier Transform Infrared Spectroscopy).In the second part of the report, the effect of diesel exhaust and ethanol exhaust on cyanuric acid evaporation rate is evaluated. Cyanuric acid is the main compound forming deposit in silencers. The instrument used in the second part is TGA. The third part consists surveying effect of Adblue, aqueous solution of urea, and additivised Adblue, surfactant added Adblue to improve its efficiency, in a patented rig that is scaled down of a silencer of truck. The most important result for the first part includes the effect of Ferrite steel treated with acetic acid that accelerated the decomposition of cyanuric acid. This result can be investigated more in order to be used in silencers to accelerate the decomposition rate of clumps formed. In the second part, it is found out that cyanuric acid evaporates faster under ethanol exhaust than diesel exhaust. The third part’s results shows that in the current assembly of pipes in the rig, Additivised Adblue loses its improved efficiency which is an interesting result for engine welding in order to avoid this type of connection in engines.

Phenotypic plasticity is hypothesized to facilitate colonization by enabling rapid adaptive responses to novel environments. The colonization of land exposed ancestrally aquatic animals to new ecological and physiological challenges, including toxic waste disposal in dry environments. The repeated evolution of terrestrial breeding in frogs creates opportunities to study developmental adaptations that may facilitate aquatic-to-terrestrial transitions. My dissertation examines the regulation of nitrogen excretion by early life stages in three anuran lineages that independently evolved terrestrial development. First, to assess developmental and environmentally cued changes, I measured N-waste accumulation over development in wet and dry environments in four species, then determined ammonia LC50 values to assess their risk of toxicity on land and the adaptive role of urea excretion. Ammonia accumulates developmentally in clutches or nests of all species and I found urea from both parental and embryonic larval sources. Embryonic larval urea excretion increased in response to dry conditions, and with ammonia accumulation, in the two species with longer terrestrial periods, and their urea excretion appears adaptive, preventing exposure to potentially lethal levels of ammonia. Where early life stages did not risk ammonia toxicity, they excreted no urea. Next, I examined biochemical mechanisms of ammonia detoxification. Urea excretion involves early onset of activity of two ornithine-urea cycle enzymes, arginase and carbamoyl phosphate synthetase, with regulatory plasticity in response to ammonia level during prolonged terrestriality and experimentally high aquatic ammonia. Glutamine synthetase activity provides another mechanism to detoxify ammonia during terrestrial development. Finally, I examined effects of prolonged terrestriality and the larval foam-making activity that supports it on larval physiology, development, and metamorphosis in Leptodactylus fragilis. Even young larvae effectively produced multiple foam nests. I found high ammonia concentrations in new larval nests, high urea excretion by developmentally arrested older larvae, and faster growth of larvae in water than while constructing nests. Larval foam-making extended terrestriality affected the aquatic larval period and age at metamorphosis, while metamorph size decreased with aquatic larval period, but increased with sibship size. Overall, my results suggest that, along with high ammonia tolerance, urea synthesis facilitates terrestrial development but carries physiological costs that may favor plasticity. Dehydration and ammonia accumulation are common, linked risks of terrestrial development. Along with parental adaptations, the evolved traits and plastic responses of early life stages are critical for transitions from aquatic to terrestrial breeding.

The increasing global population has placed significant pressure on meeting food demands, leading to the widespread use of fertilizers to enhance crop yields. Urea, being the most used fertilizer globally, has contributed to improved agricultural productivity. However, conventional urea production technologies heavily rely on fossil fuels, resulting in substantial greenhouse gas emissions and contributing to climate change.  As the demand for urea fertilizer is projected to rise in the future, there is a growing societal concern for environmental sustainability. Consequently, alternative technologies are being developed to produce urea with claims of reduced environmental impacts compared to conventional production technologies.  The objective of this master's thesis was to identify available production technologies for the materials involved in urea production, analyse different technological pathways and compare their environmental impacts and cost implications. The analysis considered several scenarios involving variations in the sources of electricity, methane gas and water used during the production process.  The analysis focused on Global Warming Potential (GWP), Primary Energy use (PE) and associated costs. The environmental analysis was conducted through a cradle-to-gate perspective based on a life-cycle impact assessment (LCIA). The cost analysis was based on a material flow cost accounting (MFCA).  The results for the green, hybrid and progressive technological pathways were benchmarked against the traditional pathway for urea production. The findings indicate that all these alternative pathways can reduce the GWP or PE values, which could be linked to the utilization of electricity sources with low GWP, such European and Swedish electricity mix, and the generation of by-products in the pathways However, within the context of the research assumptions, it was not possible to achieve a simultaneous reduction that included cost reductions alongside GWP and PE.  The study highlights the challenges of outperforming the efficiency levels of traditional technologies with other technological alternatives. Furthermore, it emphasizes the importance of carefully considering the integrations of the technologies and better utilization of residues and by-products exploring an integration of systems under an industrial symbiosis approach.  Finally, it is important to consider the trade-offs between environmental performance and cost when defining technological pathways for urea production.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第24516号 / 医博第4958号 / 新制||医||1064(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 伊藤 貴浩, 教授 岩田 想, 教授 武藤 学 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

El presente plan consiste en importar y comercializar EcoBlue (urea líquida automotriz), esta es necesaria en vehículos pesados con sistema SCR (selective catalytic reduction) con objeto de reducir la emisión de gases contaminantes de motores diésel cumpliendo así el decreto supremo N°010-2017-MINAM (los vehículos importados desde abril 2018 deben cumplir con la norma Euro IV). Nuestro mercado potencial son las empresas que cuentan con vehículos pesados (sistema SCR), el cual creció 77% en el 2019 respecto al año anterior, en el 2020 se redujo en 25% por el COVID-19 y en el primer trimestre del 2021 se refleja una recuperación del 42% respecto al primer trimestre del 2020. Nuestro mercado objetivo son empresas no corporativas (hasta diez unidades) con sede en Lima o Callao (9,650 vehículos), estas empresas están desatendidas por proveedores enfocados en empresas corporativas o cuyo core de negocio no es la venta de urea (concesionario). Nuestra declaración de posicionamiento: “Para empresas no corporativas que cuentan con vehículos pesados con el sistema SCR, EcoBlue es la mejor opción en venta de urea líquida automotriz que ofrece el mejor servicio porque estamos pendientes de las necesidades del cliente y realizamos despacho a domicilio”, asociado a nuestra propuesta de valor. En la simulación con proyección a cinco años, obtenemos un valor actual neto de S/256,524 del flujo de caja libre (inversión 100% de capital propio), además la tasa interna de retorno resulta 43% (mayor a la tasa de descuento), luego ambos indicadores muestran que sí es viable nuestro plan. / This plan consists of importing and commercializing EcoBlue (automotive urea), this is necessary in heavy vehicles with SCR (selective catalytic reduction) system in order to reduce the emission of polluting gases from diesel engines, thus complying with supreme decree No. 010- 2017-MINAM (vehicles imported from April 2018 must comply with the Euro IV standard). Our potential market is companies that have heavy vehicles (SCR system), which grew 77% in 2019 compared to the previous year, in 2020 it decreased by 25% due to COVID-19 and in the first quarter of 2021 reflects a 42% recovery compared to the first quarter of 2020. Our target market is non-corporate companies (up to ten units) based in Lima or Callao (9,650 vehicles), these companies are neglected by suppliers focused on corporate companies or whose core business is not the sale of urea (concessionaire). Our positioning statement: "For non-corporate companies that have heavy vehicles with the SCR system, EcoBlue is the best option for the sale of automotive urea that offers the best service because we are aware of the customer's needs and carry out home delivery" , associated with our value proposition. In the simulation with a five-year projection, we obtain a net present value of S / 256,524 of the free cash flow (100% equity investment), in addition the internal rate of return is 43% (greater than the discount rate), then both indicators show that our plan is viable. / Trabajo de investigación