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<p> This thesis describes the development of an ultra low frequency digital analyzer from mathematical concepts and error characteristics set out in a publication^2 co-authored by the supervisor. The development is carried to the actual construction of a practical, economical, operating instrument, capable of giving information leading directly to the mean square value and the approximate amplitude probability distribution for ultra low frequency waveforms, both periodic and non-periodic. The final detailed design is described and justified, and the error characteristics derived in the above mentioned publication are interpreted for the design. No further development of principles or error characteristics is undertaken.</p> / Thesis / Master of Engineering (MEngr)

Poly(urethane)s and poly(urethane-urea)s (PUU) are nearly ubiquitous, having been in existence since before the Second World War. Spandex, a poly(urethane-urea) elastomeric fiber, is found in nearly all articles of apparel as well as in an increasing array of other consumer items. The technology and chemistry of spandex is largely unchanged since its inception in the late 1950s, with the majority of spandex employing poly(tetramethylene ether glycol) as soft segments. Recent developments in catalyst technology have resulted in the production of ultra-low monol content poly(propylene glycol) (PPG), which is nearly difunctional (f=1.95+). This enhancement in difunctionality has potentially enabled the use of PPG as a spandex soft segment with potential spandex processing, performance, and economic benefits. PPG-based spandex elastomers were evaluated in both film and fiber form for the purpose of investigating morphological, orientational, mechanical, and thermal properties with the goal of understanding relationships between chemistry, morphology and properties. Key variables of interest were soft segment molecular weight (MW), molecular weight distribution (MWD), and composition, and hard segment content and composition. Of those, the influence of the molecular weight distribution of the polyol used for soft segments was of foremost interest and had previously been largely neglected during the course of poly(urethane) and poly(urethane-urea) research. It was found that over the range of PUU compositions suitable for production of spandex, that hard segment content and composition had little effect upon the morphology and thermal and mechanical properties. Appreciable trends as functions of soft segment molecular weight were observed. The soft segment MWD was adjusted through the addition of a low molecular weight homolog of PPG, tri(propylene glycol) (TPG), decreasing the number average soft segment MW. The results of these experiments were contrary to those for variation of soft segment molecular weight. It was determined that the low MW portion of the polyol MWD contributes to the building of hard segments in addition to or in lieu of soft segments. Incorporation of TPG in the PUUs resulted in larger, presumably less cohesive, hard domains and increased hard segment content. The TPG containing materials had enhanced tensile properties, less permanent set, and less residual orientation after deformation. These materials proved quite comparable to those using PTMEG soft segments. Comparison of film and fiber PUUs revealed only minor differences, implying that the trends and conclusions drawn from the study of films with spandex-like compositions would also hold for fibers. The key difference between films and fibers is that fibers maintain some residual ordering and orientation due to drawing of the fibers during processing. Of the processing variables investigated, none impacted the morphology as determined from small angle x-ray scattering. It was concluded, that of the various compositional variables germane to spandex, the polyol MW and MWD played key roles in development of morphology, and hence properties. The role of polyol MWD had been woefully neglected during the development of spandex previously, and was observed to be a critical variable. / Ph. D.

This work is devoted to generate knowledge and high quality experimental data of catalytic combustion at operational gas turbine conditions. The initial task of the thesis work was to design and construct a high pressure combustion test facility, where the catalytic combustion experiments can be performed at real gas turbine conditions. With this in mind, a highly advanced combustion test facility has been designed, constructed and tested. This test facility is capable of simulating combustion conditions relevant to a wide range of operating gas turbine conditions and different kinds of fuel gases. The shape of the combustor (test section) is similar to a “can” type gas turbine combustor, but with significant differences in its type of operation. The test combustor is expected to operate at near adiabatic combustion conditions and there will be no additions of cooling, dilution or secondary supply of air into the combustion process. The geometry of the combustor consists of three main zones such as air/fuel mixing zone, catalytic reaction zone and downstream gas phase reaction zone with no difference of the mass flow at inlet and exit. The maximum capacity of the test facility is 100 kW (fuel power) and the maximum air flow rate is 100g/s. The significant features of the test facility are counted as its operational pressure range (1 – 35 atm), air inlet temperatures (100 – 650 °C), fuel flexibility (LHV 4 - 40 MJ/m3) and air humidity (0 – 30% kg/kg of air). Given these features, combustion could be performed at any desired pressure up to 35 bars while controlling other parameters independently. Fuel flexibility of the applications was also taken into consideration in the design phase and proper measures have been taken in order to utilize two types of targeted fuels, methane and gasified biomass. Experimental results presented in this thesis are the operational performances of highly active precious metal catalysts (also called as ignition catalysts) and combinations of precious metal, perovskites and hexaaluminate catalysts (also called as fully catalytic configuration). Experiments were performed on different catalytic combustor configurations of various types of catalysts with methane and simulated gasified biomass over the full range of pressure. The types of catalysts considered on the combustor configurations are palladium on alumina (Pd/AL2O3), palladium lanthanum hexaaluminate (PdLaAl11O19), platinum on alumina (Pt/AL2O3),and palladium:platinum bi-metal on alumina (Pd:Pt/AL2O3). The influence of pressure, inlet temperature, flow velocity and air fuel ratio on the ignition, combustion stability and emission generation on the catalytic system were investigated and presented. Combustion catalysts were developed and provided mainly by the project partner, the Division of Chemical Technology, KTH. Division of Chemical Reaction Technology, KTH and Istituto di Ricerche sulla Combustione (CNR) Italy were also collaborated with some of the experimental investigations by providing specific types of catalysts developed by them for the specific conditions of gas turbine requirements. / <p>QC 20131125</p>

This thesis concerns the study of Ultra Low Frequency (ULF) waves during magnetospheric substorms. A wavelet algorithm which characterises magnetic ULF waves during substorm onset is presented. The algorithm is validated by comparing the spatial and temporal location of ULF wave onset to space-based observations of the aurora. It is demonstrated that the onset of ULF wave power expands coherently away from an ionospheric epicentre during the substorm expansion phase. Further, a case study of the time-domain causality of magnetotail plasma flows and ULF wave Pi2 pulsations is presented. Although highly correlated, it is demonstrated that the plasma flows cannot directly drive the ground magnetic waveforms but may be indirectly linked via a common source. Finally, results from a statistical study of ULF wave power during onset are presented. It is concluded that there is no statistical difference between historical sub-classifications of ULF waves observed during substorms.

Abstract Recently fishing industry in Taiwan is under hugely severe business environment. Due to distinctness of diplomatic situation, it is totally different competitive situation Taiwan is facing. Therefore, not only development of ultra-low-temp tuna fishing industry and managerial means and of international or regional incubate organization will be deeply described but also diamond model of Porter will be explored to analyze the competitive advantages of ultra-low-temp tuna fishing industry of Taiwan in the thesis. Definitely, the conclusion will used to develop practical plans for future severe situation. After well understanding literature about development of ultra-low-temp tuna fishing industry in Taiwan, I concluded the followings based on perspective of diamond model: 1. The first is that operations of Taiwan Tuna Association and cluster effects build the competitive advantages other countries are hard to get beyond. 2. Secondly, under relatively stable variation of tuna prices, the fishing boat owners are emphasizing on cost reduction in order to maintain business operations and get above average earnings. The ability of cost control is competitive advantage of fishing industry of Taiwan. Keywords: diamond model ,ultra-low-temp tuna fishing industry ,competitive advantage

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A low noise signal acquisition protocol is required for inner ear evoked response recordings. In this work, a parallel amplifier approach was investigated to implement a bio-signal amplifier with low voltage noise (<5nV/√Hz), and low current noise (~2fA/√Hz). A modified ear electrode was investigated to reduce biological interference and thermal noise due to high impedance electrodes. A physical model to simulate electrical activity of the inner ear was developed to evaluate the accuracy of detecting vestibular field potentials (FPs) in the presence of various noise sources. Muscle activity and noise generated from the recording apparatus were found to be the dominating sources, degrading performance of FP extraction. Contributions from this work include: the design, implementation, and validation of a bio-signal amplifier with <5nV/√Hz voltage noise, and a low impedance electrode development and placement protocol. As a result, a signal-to-noise-ratio improvement of ~11dB (compared to the current protocol) was achieved.

A low noise signal acquisition protocol is required for inner ear evoked response recordings. In this work, a parallel amplifier approach was investigated to implement a bio-signal amplifier with low voltage noise (<5nV/√Hz), and low current noise (~2fA/√Hz). A modified ear electrode was investigated to reduce biological interference and thermal noise due to high impedance electrodes. A physical model to simulate electrical activity of the inner ear was developed to evaluate the accuracy of detecting vestibular field potentials (FPs) in the presence of various noise sources. Muscle activity and noise generated from the recording apparatus were found to be the dominating sources, degrading performance of FP extraction. Contributions from this work include: the design, implementation, and validation of a bio-signal amplifier with <5nV/√Hz voltage noise, and a low impedance electrode development and placement protocol. As a result, a signal-to-noise-ratio improvement of ~11dB (compared to the current protocol) was achieved.

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