京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18471号 / 工博第3907号 / 新制||工||1600(附属図書館) / 31349 / 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 小澤 文幸, 教授 辻 康之, 教授 中村 正治 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

No description available.

This thesis presents a dedicated GPS-denied landing system designed for electric vertical takeoff and landing (eVTOL) aircraft. The system employs active fiducial light pattern localization (AFLPL), which provides highly accurate and reliable navigation during critical landing phases. AFLPL utilizes images of a constellation comprised of modulating infrared lights strategically positioned on the landing site, to determine the aircraft pose through the use of a perspective-n-point (PnP) solver. The AFLPL system underwent thorough development, enhancement, and implementation to address and demonstrate its potential in navigation and its inherent limitations. A proposed method addresses the limitations of AFLPL by using an extended Kalman filter (EKF) to fuse PnP camera pose estimates with sensor measurements from an inertial measurement unit (IMU), attitude heading reference system (AHRS), and optional global positioning system (GPS). The EKF estimation is reported to significantly enhance the accuracy, reliability, and update frequency of the aircraft state estimation. To refine and validate the AFLPL and EKF algorithms, a simulation was developed, consisting of an eVTOL executing a glideslope landing trajectory. Furthermore, a hardware system consisting of a multirotor and infrared light ground units was implemented to test these methods under real-world conditions. This research culminated in the successful demonstration of the AFLPL-based estimation system's efficacy through an autonomous, GPS-denied landing flight test, affirming its potential to improve the navigation and control of eVTOL aircraft lacking access to GPS information.

Wireless Sensor Networks (WSNs) are popular for their wide scope of application domains ranging from agricultural, medical, defense, industrial, social, mining, etc. Many of these applications are in outdoor type environments that are unregulated and unpredictable, thus, potentially hostile or physically harsh for sensors. The popularity of WSNs stems from their fundamental concept of being low cost and ultra-low power wireless devices that can monitor and report sensor readings with little user intervention, which has led to greater demand for WSN deployment in harsh industrial environments. We argue that there are a new set of architectural challenges and requirements imposed on the hardware, software, and network architecture of a wireless sensor platform to operate effectively under harsh industrial environments, which are not met by currently available WSN platforms. We propose a new sensor platform, called Sprouts. Sprouts is a readily deployable, physically rugged, volumetrically miniature, modular, network standard, plug-and-play (PnP), and easy to use sensor platform that will assist university researchers, developers, and industrial companies to evaluate WSN applications in the field, and potentially bring about new application domains that were previously difficult to accomplish using off the shelf WSN development platforms. Therefore, we addresses the inherent requirements and challenges across the hardware, software, and network layer required for designing and implementing Sprouts sensor platform for harsh industrial environments. We fully implement the hardware, network, and software architecture for the Sprouts platform and verify that they meet the requirements for harsh environments. We deploy the Sprouts platform customized with our PnP ultrasound sensor module in an industrial application to monitor the health conditions of Syncrude's vibration screens operating under extreme harsh conditions. Sprouts has been showcased in OCE Discovery 2011, and has been proven to be extremely valuable for industrial mining companies such as Syncrude. / Thesis (Ph.D, Computing) -- Queen's University, 2013-09-28 16:14:48.223

Bandgap reference circuits are used in a host of analog, digital, and mixed-signal systems to establish an accurate voltage standard for the entire IC. The accuracy of the bandgap reference voltage under steady-state (dc) and transient (ac) conditions is critical to obtain high system performance. In this work, the impact of process, power-supply, load, and temperature variations and package stresses on the dc and ac accuracy of bandgap reference circuits has been analyzed. Based on this analysis, the a bandgap reference that 1. has high dc accuracy despite process and temperature variations and package stresses, without resorting to expensive trimming or noisy switching schemes, 2. has high dc and ac accuracy despite power-supply variations, without using large off-chip capacitors that increase bill-of-material costs, 3. has high dc and ac accuracy despite load variations, without resorting to error-inducing buffers, 4. is capable of producing a sub-bandgap reference voltage with a low power-supply, to enable it to operate in modern, battery-operated portable applications, 5. utilizes a standard CMOS process, to lower manufacturing costs, and 6. is integrated, to consume less board space has been proposed. The functionality of critical components of the system has been verified through prototypes after which the performance of the complete system has been evaluated by integrating all the individual components on an IC. The proposed CMOS bandgap reference can withstand 5mA of load variations while generating a reference voltage of 890mV that is accurate with respect to temperature to the first order. It exhibits a trimless, dc 3-sigma accuracy performance of 0.84% over a temperature range of -40°C to 125°C and has a worst case ac power-supply ripple rejection (PSRR) performance of 30dB up to 50MHz using 60pF of on-chip capacitance. All the proposed techniques lead to the development of a CMOS bandgap reference that meets the low-cost, high-accuracy demands of state-of-the-art System-on-Chip environments.

In this study, we have explored the combination of a novel Purine Nucleoside Phosphorylase mediated Gene-Directed Enzyme Prodrug Therapy (PNP-GDEPT) with chemotherapeutics, Taxotere and/or Carboplatin to target prostate and ovarian cancer (PC & OC). PNP converts the prodrug (Fludarabine-phosphate) to a toxic purine, 2-fluoroadenine (2FA) that inhibits RNA/DNA synthesis. Taxotere is active against late stage PC whilst carboplatin is first line therapy for OC. Neither modality is adequately effective. We expect that a combination will target heterogeneity via cytotoxicity to diverse cancer cell populations leading to effective synergies, which may improve efficacy and quality of life. For PC, Synergy between Ad-PNP-GDEPT and Taxotere were assessed in vitro and in vivo. Cell killing effects of combination led to significant synergistic killing of human PC-3 & murine RM1 PC cells accompanied by enhanced apoptosis. A lower individual dose (by up to 8 fold) led to enhanced efficacy. In vivo, the combination regimen given at the suboptimal doses led to reduction in local tumour (PC-3 & RM1) growth in nude and in C57BL/6 mice, respectively. A significant reduction in lung RM1 colony numbers indicated enhanced systemic efficacy. Combination treated mice also displayed significantly improved survival (25 days vs 15 days for control mice). Importantly, the condition of combination treated mice (e.g. weight loss) was better than those given individual treatments. The possible involvement of the immune system in this enhanced effect is under investigation. For OC, three-way synergy between Ad-PNP-GDEPT, Taxotere and carboplatin was effectively demonstrated in SKOV-3 and OVCAR-3 cells. This was significantly greater than bimodal or individual treatments. A 10-50 fold dose reduction of individual treatments was effective when combined, accompanied by enhanced apoptosis. Western-blotting analyses revealed a shift in the expression of anti-apoptotic and proapoptotic proteins upon treatment with various combinations. This is the first demonstration of synergy between these modalities.

No description available.

This thesis deals with the analysis of the measuring equipment for the testing of inductive sensors in the climatic chamber, which mainly highlights the faults and deficiencies of this device. Based on this analysis, a new measurement system is designed to eliminate these or all the deficiencies. Several new useful features are added to the new design of the measuring system.

Sol-gel-based silica monoliths with hierarchical mesopores/macropores are promising catalyst support and flow reactors. Here, we report the successful preparation of cylindrically shaped Pt-loaded silica monoliths (length: 2 cm, diameter: 0.5 cm) with a variable mean macropore width of 1, 6, 10, or 27 μm at a fixed mean mesopore width of 17 nm. The Pt-loaded monolithic catalysts were housed in a robust cladding made of borosilicate glass for use as a flow reactor. The monolithic reactors exhibit a permeability as high as 2 μm2 with a pressure drop below 9 bars over a flow rate range of 2–20 cm3 min−1 (solvent: water). The aqueous-phase hydrogenation of p-nitrophenol to p-aminophenol with NaBH4 as a reducing agent was used as a test reaction to study the influence of mass transfer on catalytic activity in continuous flow. No influence of flow rate on conversion at a fixed contact time of 2.6 s was observed for monolithic catalysts with mean macropore widths of 1, 10, or 27 µm. As opposed to earlier studies conducted at much lower flow velocities, this strongly indicates the absence of external mass-transfer limitations or stagnant layer formation in the macropores of the monolithic catalysts.

The two stage Lucite Alpha Process for the industrial manufacturing of methyl methacrylate (MMA) represents one of the most efficient technologies currently available for the large scale production of this important chemical commodity. The second stage of this process, which involves the condensation of methyl propanoate (MeP) with formaldehyde over a heterogeneous fixed bed catalyst, however, still shows great scope for improvement. Herein the development of a novel homogeneous catalytic system that would promote the condensation of either propanoic acid or MeP with formaldehyde is explored. Since C–C bond forming reactions which proceed via C–H activation pathways typically display high atom efficiency, our efforts were particularly focussed on employing a functionalisation strategy that is mediated by C–H activation. In the case of propanoic acid, the possibility of achieving regioselective α-methylenation by linking the substrate to phosphorus was evaluated. Thus, a series of acyloxyphosphines and acylphosphites derived from either propionic acid or phenylacetic acid was prepared and, where stability allowed, fully characterised. Some of the resultant simple mixed anhydrides posed problems relating to their stability, and the stabilisation of such ligand systems by using electronic and / or steric effects was therefore explored. In addition, the coordination chemistry and in solution behaviour of Rh(I) and Ru(II) complexes containing these ligands was examined. Similar to the free ligands, complexes derived from these mixed anhydrides rearranged in solution via a number of decomposition pathways, with the specific pathway dependent on the nature of the auxiliary ligands. For most of these complexes, however, ligand decarbonylation was the route of preference for decomposition. Despite the instability of these complexes, a selection of Rh(I) mixed anhydride complexes were assessed for their potential as C-H activation catalysts in reactions aimed at the α-methylenation of saturated carboxylic acids. Furthermore, the stabilisation of Rh(I) mixed anhydride complexes with chelating auxilary ligands, such as bisphosphines or N-substituted diphosphinoamines, was explored. In particular, a series of new Rh(I) mixed anhydride complexes containing dppe, dppb and dppbz as secondary ligands were prepared and the effects of these secondary ligands on the in solution stability of these complexes assessed. As MeP represents the final product in the first stage of the Alpha process and not propanoic acid, the utilisation of PNP iridium pincer complexes in the regioselective sp³ C–H activation of MeP and related esters was also examined. The factors that govern the regioselectivity of such reactions were of great interest to us and, in particular, the effects of water on the reactivity and regioselectivity of these reactions were explored. For MeP, preferential C–H activation of the methoxy group was found to proceed under anhydrous conditions and the catalytic functionalisation of this site with ethene using this activation approach was considered. Formaldehyde, employed in the second stage of the Alpha process, is a difficult substance to manufacture and handle, especially on a large scale. A preliminary study on the in situ production of anhydrous formaldehyde via the catalytic dehydrogenation of methanol was therefore performed. During this study, catalytic systems based on carbonate salts and / or transition metal complexes were considered. In the hope of reducing the number of steps required in the production of MMA, a new one-pot cascade reaction for the indirect α-methylenation of MeP with methanol was developed. Although the production of MMA using this system only proceeded with low efficiency, the obtained results serve as an important proof of concept for future developments in this area. Finally, the capacity of a series of simple bases to catalyse the condensation of MeP with formaldehyde was assessed as part of a fundamental study directed towards determining the factors that govern the efficiency of this reaction. In addition, the extent to which each base effects the deprotonation in the α-position of MeP was determined with the aid of deuterium labelling experiments. Similarly, using sodium propanoate as model base a rough estimate of the kinetics of deprotonation could be made based on the degree of deuterium incorporation over time. These studies suggested that the low efficiency of this condensation reaction is not caused by ineffective deprotonation but rather by the weak nucleophilicity of the generated carbanion. For this reason, attempts to increase the electrophilicity of formaldehyde through Mannich-type condensations reactions involving secondary amine and carboxylic acid additives were made.