The purpose of this study is to analyze how university students, who are not members of a political party, experiencing existing selective and collective incentives for involvement in a political party. Furthermore, the study will highlight incentives which could help the political parties to increase their membership. The study is based on seven interviews and the respondents were selected after conducting a survey of students’ political involvement. The interviews were analyzed through the theory of selective and collective incentives.  The study shows that the incentives, both selective and collective, for involvement in a political party in general are weak and that the costs in terms of time, money and education are seen as too high. The respondents have a range of suggestions to increase party involvement, including increased party information, better education, increased financial incentives and a more active membership recruitment. The respondents also highlight some collective incentives such as an increased ideological focus and a greater focus on the political party´s own politics. The collective incentives are harder to achieve though they might be most vital for increased involvement. A common feeling amongst the respondents is that they are inclined to become involved in politics if they feel a change is vital for society.

The potential application of a hydrogel-based strong anion-exchange (Q) membrane to purify plasmid DNAs was evaluated. The maximum binding capacity of plasmid DNA was estimated to be 12.4 mg/ml of membrane volume with a plasmid DNA recovery of ~ 90%, which is superior to other commercially available anion-exchange resins and membranes. The membrane was able to retain its structural integrity and performance after multiple cycles of usage (> 30 cycles). The inherent properties of plasmid DNA, membrane adsorbent, and the ionic environment on membrane performance were identified as the factors affecting membrane performance and their effects were systematically investigated. Plasmid DNAs with smaller tertiary structure have shorter dynamic radius and/or lowersurface charge densities, which tended to have a better adsorption and recovery than those with larger tertiary structure. Environmental Scanning Electron Microscopy (ESEM) revealed that the hydrogel structure is more porous on one side of membrane than the other, and higher plasmid DNA adsorption and recovery capacities were observed if the more porous side of the membrane was installed upward of flow in the chromatographic unit. ESEM also revealed improved pore distribution and increased membrane porosity if membrane was pre-equilibrated in the buffer solution for 16 hours. The development of better flow through channel in the hydrogel membrane upon extensive soaking further improved plasmid DNA adsorption and recovery capacities. The ionic environment affects the tertiary size of plasmid DNA; and the optimal operating pH of membrane chromatography was different for the plasmid DNAs investigated in this study. The relative contribution of these factors to improve membrane chromatography of plasmid DNAs was analyzed using statistical modeling. It was found that the adsorption of plasmid DNA was mainly affected by the available adsorptive area associated with membrane porosity, whereas the recovery of plasmid DNAs was mainly affected by the environmental pH. A novel, RNase-free, and potentially scalable bioprocess was synthesized using the hydrogel membrane as the technology platform for the manufacturing of pharmaceutical-grade plasmid DNA. High bioprocess recovery and product quality were primarily associated with the optimal integration of impurity removal by calcium chloride precipitation and anion-exchange membrane chromatography and the implementation of isopropanol precipitation as a coupling step between the two impurity-removing steps. Complete removal of total cellular RNA impurity was demonstrated without the use of animal-derived RNase. High-molecular-weight (HMW) RNA and genomic DNA (gDNA) were removed by selective precipitation using calcium chloride at an optimal concentration. Complete removal of the remaining low-molecular-weight (LMW) RNA was achieved by membrane chromatography using the high-capacity and high-productive hydrogel membrane. The simultaneous achievement of desalting, concentrating and buffer exchange by the coupling step of isopropanol precipitation and the high efficiency and resolution of DNA-RNA separation by anion-exchange membrane chromatography significantly reduced the operating complexity of the overall bioprocess, increased the overall recovery of plasmid DNA, and enhanced product quality by removing trace amounts of impurities of major concern for biomedical applications, such as gDNA, proteins, and endotoxin.

The diesel engine is growing in popularity due to its energy efficiency and solving the emissions issues associated with diesel engine exhaust would clear the way for further growth. The key pollutants are NOx, particulate matter and unburned hydrocarbons. Selective catalytic reduction (SCR) catalysis is likely the best choice for NOx control. In SCR, NH3 selectively reacts with NOx to form N2 – the selectivity refers to NH3 reacting with NOx instead of the abundant O2. Urea is used as the NH3 source, being injected into the exhaust as an aqueous solution where the urea decomposes and NH3 is generated. Spatial resolution characterization techniques have been gaining attention in the catalysis field because of the higher level of information provided. In this thesis, a new spatial resolution technique, called SpaciFTIR (spatially-resolved, capillary-inlet Fourier transform infra-red spectroscopy), was developed, which overcomes the interference of water in the detection of NH3 in an earlier developed technique, SpaciMS (spatially-resolved, capillary-inlet mass spectrometry). With the new test method, three SCR topics were addressed. First, the three key SCR reactions were spatially resolved. These are the standard SCR reaction (2NO + 2NH3 + 1/2O2 = 2N2 + 3H2O), the fast SCR reaction (NO + NO2 + 2NH3 = 2N2 + 3H2O), and NO2-SCR, (6NO2 + 8NH3 = 7N2 + 12H2O). Results show that in the presence of NO2, but at a NO2/NOx ratio < 0.5, the fast SCR reaction proceeds followed by the standard SCR reaction, i.e. in series. If the NO2/NOx ratio exceeds 0.5, the NO2-SCR and fast SCR reactions occur in parallel. Compared to the standard integral test method, this spatial resolution technique clearly showed such trends. Secondly, the spatial resolution technique was used to characterize the effects of thermal aging on catalyst performance. It was found that for a highly aged catalyst, there was a radial activity profile due to an inhomogeneous temperature distribution in the process of aging. Aging effects on various key SCR reactions, i.e. NO oxidation, NH3 oxidation, and the reduction reactions, were studied. Last but not least, for the purpose of passive SCR system development, transient NH3 storage profiles along the monolith channel were measured with SpaciFTIR. Passive SCR is a system where the NH3 is generated on an upstream catalyst, such as a three-way catalyst or lean-NOx trap, instead of via urea injection. In such a system, NH3 is therefore not constantly being fed to the SCR catalyst, but “arrives” in pulses. Factors such temperature, NH3 concentration, pulsing time, flow rate and thermal aging were investigated. For the first time, NH3 migration was observed and its effect on SCR reactions along the length of catalyst was studied.

The reaction mechanism for the Selective Catalytic Reduction (SCR) of NO by NH3 on V2O5 surface was simulated by means of density functional theory (DFT) calculations performed at B3LYP/6-31G** level. As the initiation reaction, ammonia activation on V2O5 was investigated. Coordinate driving calculations showed that ammonia is adsorbed on Br&oslash / nsted acidic V-OH site as NH4 + species by a nonactivated process with a relative energy of -23.6kcal/mol. Vibration frequencies were calculated as 1421, 1650, 2857 and 2900cm-1 for the optimized geometry, in agreement with the experimental literature. Transition state with a relative energy of -17.1kcal/mol was also obtained. At the end of the Lewis acidic ammonia interaction calculations, it was observed that ammonia is hardly adsorbed on the surface. Therefore, it is concluded that the SCR reaction is initiated more favorably by the Br&oslash / nsted acidic ammonia adsorption. As the second step of the SCR reaction, NO interaction with the preadsorbed NH4 + species was investigated. Accordingly, NO interaction results in the formation of gas phase NH2NO molecule with a relative energy difference of 6.4kcal/mol. For the rest of the reaction sequence, gas phase decomposition of NH2NO was considered. Firstly, one of the hydrogen atoms of NH2NO migrates to oxygen. It then isomerizes in the second step. After that, the reaction proceeds with the isomerization of the other hydrogen. Finally, a second hydrogen atom migration to the oxygen leads to the formation of N2 and H2O. Total relative energy for this reaction series was obtained as -60.12kcal/mol, in agreement with the literature.

Selective laser sintering (SLS) is a rapid prototyping method in which three-dimensional objects are constructed by sintering thin layers of a variety of powdered materials via laser beam. In SLS, as in most other Rapid Prototyping methods, the produced parts exhibit varying degrees of intrinsic porosity due to the discrete nature of layer-by-layer production. Selective scanning and discrete bonding of individual particles or clusters of particles impart local porosity, which is mostly an undesired trait as the part integrity decreases with increased porosity. However, there are a number of emerging or potential applications as in tissue engineering and composite/functionally graded materials, in which part porosity and its control during production are needed. In this study, the manufacturing capabilities of selective laser sintering are investigated towards producing predesigned porous structures using a polymeric powder. The porous structures are characterized in two main categories: regular porous structures, which involve geometries such as predesigned holes and lattice structures that have orderly porous architecture, and irregular porous structures, which exhibit random pore architecture that is intrinsic in all SLS parts. The limitations of producing regular porous structures are investigated, identified and quantified, based on hole size and dimensional accuracy. An experimental analysis based on design of experiments is employed to investigate the effects of processing parameters on the resulting macroscopic pore properties of irregular porous structures. A mathematical relation is developed to quantify and predict the relations between the SLS process parameters: Laser power, hatching distance, laser scan spacing, and the resulting apparent mass density (as a measure of porosity). The subsequent tests verify accuracy of the developed empirical model.

In this study, we consider the disassembly problem of end-of-life (EOL) products for recovering valuable parts or assemblies. All parts obtained by disassembly processes of an EOL product may not be profitable due to their high recovery costs. Our problem is to select the parts to be released and determine the associated disassembly tasks so as to maximize the total profit. We first tackle the simple part selection problem, and then introduce a time constraint for the tasks to be performed for selected parts and search for incomplete time constrained sequences. We formulate our first problem as a Mixed Integer Problem and show that the constraint set of this formulation is totally unimodular. We also provide the dual formulation of our problem and its interpretation. For time-constrained part selection problem we propose a branch-and-bound algorithm. We first develop some reduction mechanism to reduce the size of the problem. Our solution procedure is capable of solving problems with up to 94 parts and tasks.

Willfully controlling the focus of an extracellular stimulus remains a significant challenge in the development of neural prosthetics and therapeutic devices. In part, this challenge is due to the vast set of complex interactions between the electric fields induced by the microelectrodes and the complex morphologies and dynamics of the neural tissue. Overcoming such issues to produce methodologies for targeted neural stimulation requires a system that is capable of (1) delivering precise, localized stimuli a function of the stimulating electrodes and (2) recording the locations and magnitudes of the resulting evoked responses a function of the cell geometry and membrane dynamics. In order to improve stimulus delivery, we developed microfabrication technologies that could specify the electrode geometry and electrical properties. Specifically, we developed a closed-loop electroplating strategy to monitor and control the morphology of surface coatings during deposition, and we implemented pulse-plating techniques as a means to produce robust, resilient microelectrodes that could withstand rigorous handling and harsh environments. In order to evaluate the responses evoked by these stimulating electrodes, we developed microscopy techniques and signal processing algorithms that could automatically identify and evaluate the electrical response of each individual neuron. Finally, by applying this simultaneous stimulation and optical recording system to the study of dissociated cortical cultures in multielectode arrays, we could evaluate the efficacy of excitatory and inhibitory waveforms. Although we found that the proximity of the electrode is a poor predictor of individual neural excitation thresholds, we have shown that it is possible to use inhibitory waveforms to globally reduce excitability in the vicinity of the electrode. Thus, the developed system was able to provide very high resolution insight into the complex set of interactions between the stimulating electrodes and populations of individual neurons.

京都大学 / 新制・課程博士 / 博士(エネルギー科学) / 甲第23999号 / エネ博第435号 / 新制||エネ||82(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻 / (主査)教授 野平 俊之, 教授 萩原 理加, 教授 宇田 哲也 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

This thesis presents data which support cochlear involvement in attentional listening. It has been previously proposed that the descending auditory pathways, in particular the medial olivocochlear system, play a role in reducing the cochlea's response to noise in a process known as antimasking. This hypothesis was investigated in human subjects for its potential impact on the detection of signals in noise following auditory cues. Three experimental chapters (Chapters 3, 4 and 5) are described in this thesis. Experiments in the first chapter measured the effect of acoustic cues on the detection of subsequent tones of equal or different frequency. Results show that changes in the ability to detect signals following auditory cues are the result of both enhanced detection for tones at the cued frequency, and suppressed detection for tones at non-cue frequencies. Both effects were measured to be in the order of ~3 dB. This thesis has argued that the enhancement of a cued tone is the implicit result of an auditory cue, while suppression of a probe tone results from the expectation of a specific frequency based on accumulated experience of a listening task. The properties of enhancement support the antimasking hypothesis, however, the physiological mechanism for suppression is uncertain. In the second experimental chapter, auditory cues were replaced with visual cues (representing musical notes) whose pitch corresponded to the target frequency, and were presented to musician subjects who possessed absolute or relative pitch. Results from these experiments showed that a visual cue produces the same magnitude of enhancement as that produced by an acoustic cue. This finding demonstrates a cognitive influence on the detection of tones in noise, and implicates the role of higher centres such as those involved in template-matching or top-down control of the efferent pathways. The final experimental chapter repeated several of the experiments from the first chapter on subjects with various forms of hearing loss. The results indicate that subjects with an outer hair cell deficit (concomitant with a sensorineural hearing loss) do not exhibit an enhancement of cued frequencies or a suppression of unexpected frequencies to the same extent as the normal-hearing subjects. In addition, one subject with a long-standing conductive hearing loss (with normal cochlear function) produced an enhancement equivalent to that of the normalhearing subjects. These findings also support the role of the medial olivocochlear system and the outer hair cells in antimasking. It is the conclusion of this thesis that enhancement most likely results from a combination of changes in receptive field characteristics, at various levels of the auditory system. The medial olivocochlear system is likely to be involved in unmasking a portion of the signal at the cochlear level, which may be influenced by both acoustic reflex pathways or higher centres of the brain.

No abstract.