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Study on Resistive Switching Phenomenon in Metal Oxides for Nonvolatile Memory / 不揮発性メモリに向けた金属酸化物における抵抗スイッチング現象に関する研究Iwata, Tatsuya 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18285号 / 工博第3877号 / 新制||工||1595(附属図書館) / 31143 / 京都大学大学院工学研究科電子工学専攻 / (主査)教授 木本 恒暢, 教授 藤田 静雄, 准教授 掛谷 一弘 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
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Nanoscale Electronic Properties of Conjugated Polymer Films Studied by Conductive Atomic Force Microscopy / 電流計測原子間力顕微鏡による共役高分子薄膜のナノ電子物性の解明Osaka, Miki 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20406号 / 工博第4343号 / 新制||工||1673(附属図書館) / 京都大学大学院工学研究科高分子化学専攻 / (主査)教授 大北 英生, 教授 辻井 敬亘, 教授 竹中 幹人 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
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Development of Ni(CH3-Salen) Conductive Polymer for use in Li-ion CathodesO'Meara, Cody A. 06 December 2018 (has links)
No description available.
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Metal Isotope Fractionation Induced by Fast Ion Conduction in Natural and Synthetic Wire SilverAnderson, Calvin J. 30 July 2018 (has links)
No description available.
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Developing Engineered Thin Films for Applications in Organic Electronic and Photonic Devices.Nemani, Srinivasa Kartik January 2018 (has links)
No description available.
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Engineering Approaches to Control and Prediction of Upper Extremity MovementBurns, Alexis Meashal 29 August 2019 (has links)
No description available.
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SYNTHESIS, CHARACTERIZATION, AND MATERIAL PROPERTIES OF IONIC THIOL-YNE ELASTOMERSNettleton, Jason William 30 October 2020 (has links)
No description available.
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Conductive Polymers Derived Heteroatom Doped Carbon Catalysts forOxygen Reduction ReactionHonorato, Ana Maria Borges 22 January 2021 (has links)
No description available.
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Electrically conductive hollow fiber membrane development: addressing the scalability challenges and performance limits of conductive membrane fabricationLarocque, Melissa January 2020 (has links)
Electrically conductive membranes (ECMs) are of significant research interest for their ability to mitigate fouling, enhance separation capacity, and induce electrochemical degradation of contaminants. Most ECM development has been in flat sheet format suitable for laboratory studies; in industrial applications, formats such as hollow fiber (HF) are preferred for their high packing density. While ECMs in HF format are emerging in research, these techniques typically employ the same methods proven for flat sheet, often involving direct deposition of conductive material onto a support membrane with no further investigation into how the deposition process affects ECM properties. This is a significant challenge for long (~1 m) HF membranes where coating uniformity is essential to ensure consistent performance. The goal of this project was to fabricate conductive HF membranes, ensuring uniform performance along the fiber. In this work, we have developed a “crossflow deposition” technique to deposit a uniform layer of single walled/ double walled carbon nanotubes (SW/DWCNTs) onto the interior surface of commercial polyether sulfone HF membranes. In a design-of-experiments model, feed pressure and crossflow velocity were shown to directly impact composite membrane conductivity and permeability. The highest permeability (~2900 LMH/bar) and conductivity (~670 S/m) were both achieved at the high pressure (0.2 bar) and high crossflow velocity (1.06 cm/s) condition. An inverse relationship was identified between conductivity and permeability for 29 different HF membranes coated under various flow and particle loading conditions. Similar trends were evident in ECM literature when comparing 80 membranes across 38 papers, covering various conductive materials, separation types, configurations, and applications. Metallic-based ECMs outperformed graphitic nanomaterial or conductive polymer-based ECMs with conductivities three orders of magnitude higher. This review also revealed a wide variation in performance testing with 35 unique pollutants in 63 total tests, indicating a need for standardization to accurately compare ECMs and a need for testing with more realistic feed sources. Finally, electrochemical degradation of methyl orange using the CNT-coated HF membranes was evaluated in batch and continuous removal experiments. Although no significant MO removal was detected in either configuration, these modules can be used for further optimization in terms of targeted conductivity, contact time, and electrochemical parameters such as applied voltage. This work highlights the existence of a conductivity/ permeability trade-off in ECM development and how manipulation of flow parameters during deposition can impact this trade-off in HF membrane development. / Thesis / Master of Applied Science (MASc) / Membrane separation technologies are a common purification strategy in many fields due to their simplicity and low energy requirements. Membranes operate by rejecting particles from feed water based on their chemical or physical properties such as size or charge. Long-term membrane operations are limited by fouling, incurring large operating costs for frequent cleaning cycles and downtime. Furthermore, traditional membrane separations only physically remove particles, presenting a risk for contaminant re-introduction into the environment. Electrically conductive membranes are an emerging strategy for addressing these concerns due to their demonstrated antifouling, enhanced selectivity, and redox capabilities. To date, these membranes have almost exclusively been developed as flat sheets with limited research into other membrane formats. Hollow fiber membranes resemble thin tubes ~1 mm in diameter and up to ~1 m in length where filtration occurs through the tubular wall of the fiber; the small diameter allows for hundreds of fibers to pack into an individual module, thus maximizing throughput. In this thesis, several issues with hollow fiber conductive membrane fabrication are addressed to ensure consistent performance along the length of the fiber. A key trade-off between membrane surface conductivity and throughput was found to exist universally in the conductive membrane field. This knowledge can be used to select fabrication methods and parameters to target certain performance ranges.
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Electrically Conductive Membranes for Water and Wastewater Treatment: Their Surface Properties, Antifouling Mechanisms, and ApplicationsHalali, Mohamad Amin January 2021 (has links)
Climate change, water stress, and rapid population growth have increased the need
to manage water resources through innovative sustainable technologies. Decentralized
systems such as membrane treatment trains have become increasingly important to provide
high volumes of potable water to millions of people. Pressure-driven membrane systems
have dominated separation processes due to their low cost, small footprint, ease of
operation, and high permeate quality. Conventionally, pressure-driven membranes are
classified into microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse
osmosis (RO). MF and UF membranes operate under low pressure (< 7 bar, <~100 psi).
They can separate a variety of large particles such as bacteria, natural organic matter,
suspended solids, and colloids. In contrast, NF and RO membranes are more energy-intense
due to operating at high pressures (7 – 80 bar, ~100 – 1200 psi) and can remove small
molecules such as ions, pharmaceuticals, and heavy metals. Fouling is a primary challenge
with membranes that compromises the membrane performance, increases energy
consumption, and reduces the membrane lifetime. Many strategies are used to address
fouling, such as pre-treatment (pH adjustment, screening, coagulation), membrane
modification (chemical and morphological properties), and membrane cleaning (physical,
chemical). However, such strategies increase operational expenditures, produce waste
products that can impact the environment, and negatively impact membrane lifetimes.
Recently, electrically conductive membranes (ECMs) have been introduced to
address the challenges with traditional membranes. They contain conductive surfaces that
offer self-cleaning and antifouling properties across the surface in response to electrical potential externally applied to them. ECMs are advantageous as compared to traditional
membranes because (a) they are more effective in treating foulants as they target foulants
at the membrane/solvent interface, (b) they are more economical and environmentally
friendly as they reduce the need for chemical consumption, and (c) they can be responsive
to fouling conditions as their antifouling mechanisms can be easily manipulated by
changing the applied current type (positive, negative, direct current, alternating current) to
match the foulant.
ECMs have been formed from all categories of membranes (MF, UF, NF, MD, FO,
and RO) with a range of applications. Despite the remarkable progress in demonstrating
their excellent antifouling performance, there are many hurdles to overcome before they
can be commercialized. Two of these are (a) a fundamental understanding of their
underlying mechanisms, (b) surface materials that can withstand extreme chemical and
electrical conditions. In this work, we have comprehensively discussed antifouling
mechanisms with respect to surface polarization and elaborated on the impact of
electrically-induced mechanisms on four major fouling categories. i.e., biofouling, organic
fouling, mineral scaling, and oil wetting. In addition, we characterized surface properties
of a common electrically conductive composite membrane composed of carbon nanotubes
(CNTs) and polyvinyl alcohol (PVA). We then investigated the impact of cross-linkers in
CNT/PVA network on transmembrane flux, electrical conductivity, hydrophilicity, and
surface roughness. In addition, we proposed standard, practical, and straightforward
methodologies to detect and quantify the electrochemical, physical, and mechanical
stability of ECMs, using chronoamperometry and cyclic voltammetry, an evaluation of polymer leaching from membranes, and micro mechanical scratch testing, respectively. Our
methods can readily be extended to all membrane-based separation processes and different
membrane materials (carbonaceous materials, ceramics, metal-based, and polymers).
To demonstrate the antifouling properties of ECMs, we challenged ECMs with
mixed-bacterial cultures in a flow-through system. Although ECMs showed high rejection,
comparable flux, and excellent self-cleaning performance under application of electrical
potential, understanding the relationship between applied electrical currents and antifouling
mechanisms demands a well-controlled investigation. To this end, we quantified the impact
of electrochemically-induced acidic conditions, alkaline conditions, and H2O2
concentration on model bacteria, Escherichia Coli. We first quantified the electrochemical
potential of CNT-based ECMs in generating stressors such as protons, hydroxyl ions, and
H2O2, under a range of applied electrical currents (± 0-150 mA). Next, these individual
stressors with identical magnitude were imposed on E. Coli cells and biofilms in batch and
flow-through systems, respectively. This thesis guides researchers to understand the
underlying antifouling mechanisms associated with ECMs, how to match the mechanisms
to the application of ECMs, and offers benchmarks for making practical ECMs. / Thesis / Doctor of Philosophy (PhD)
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