<p>Proteins have such structural features that they may interact with different types of surfaces by all possible forces, i.e., electrostatic, hydrogen bonding, hydrophobic. In this thesis two different types of coatings for fused silica capillaries aimed to eliminate such interactions have been studied. The first is a covalent, electroosmosis-free coating with polyacrylamide (PAA) and the second involves a non-covalent coating with the quaternary ammonium compound N, N-didodecyl –N, N- dimethylammonium bromide (DDAB) with a strong anodic electroosmosis. Optimal conditions regarding efficiency and resolution were established by variations of the composition and ionic strengths of buffers at pH below the isoelectric point of the proteins. To achieve high efficiency and resolution the choice of buffer constituents was extremely important. </p><p>The PAA coating was very stable at neutral and acidic conditions. Ammonium acetate (0.12 M) and ammonium hydroxyacetate (0.15 M) both at pH 4 provided the best separations with plate numbers up to 1 700 000 plate/m that is among the highest reported in the literature. Capillaries coated with DDAB were stable enough to, without recoating, permit consecutive separations of the proteins up to 9 hours (90 injections). High apparent efficiencies (over 1 million plates/m) were achieved with ammonium acetate (0.07 M), ammonium hydroxyacetate (0.08 M) and sodium phosphate (0.1 M) at pH 4. </p><p>Zone broadening was studied by determination of the variance contributions from all main parameters. Significant variances were contributions from longitudinal diffusion, capillary curvature, injection plug, detector time response and detector slit width while other variances, e.g., variances for Joule heat and vertical sedimentation were negligible. The remaining undetermined variance may have its origin in all types of relatively slow interactions including adsorption onto the capillary surfaces and protein-buffer component interactions. The results indicate that the latter is the main cause to zone broadening in protein separations.</p>

Proteins have such structural features that they may interact with different types of surfaces by all possible forces, i.e., electrostatic, hydrogen bonding, hydrophobic. In this thesis two different types of coatings for fused silica capillaries aimed to eliminate such interactions have been studied. The first is a covalent, electroosmosis-free coating with polyacrylamide (PAA) and the second involves a non-covalent coating with the quaternary ammonium compound N, N-didodecyl –N, N- dimethylammonium bromide (DDAB) with a strong anodic electroosmosis. Optimal conditions regarding efficiency and resolution were established by variations of the composition and ionic strengths of buffers at pH below the isoelectric point of the proteins. To achieve high efficiency and resolution the choice of buffer constituents was extremely important. The PAA coating was very stable at neutral and acidic conditions. Ammonium acetate (0.12 M) and ammonium hydroxyacetate (0.15 M) both at pH 4 provided the best separations with plate numbers up to 1 700 000 plate/m that is among the highest reported in the literature. Capillaries coated with DDAB were stable enough to, without recoating, permit consecutive separations of the proteins up to 9 hours (90 injections). High apparent efficiencies (over 1 million plates/m) were achieved with ammonium acetate (0.07 M), ammonium hydroxyacetate (0.08 M) and sodium phosphate (0.1 M) at pH 4. Zone broadening was studied by determination of the variance contributions from all main parameters. Significant variances were contributions from longitudinal diffusion, capillary curvature, injection plug, detector time response and detector slit width while other variances, e.g., variances for Joule heat and vertical sedimentation were negligible. The remaining undetermined variance may have its origin in all types of relatively slow interactions including adsorption onto the capillary surfaces and protein-buffer component interactions. The results indicate that the latter is the main cause to zone broadening in protein separations.

In order to fully understand the role methane (CH₄) plays in the microwave emission spectra of the deep atmospheres of the outer planets, over 280 laboratory measurements of the opacity of ammonia in a methane environment have been made in the 5-20 cm wavelength range. All opacity measurements were made with either 100 or 200 mbars of ammonia and with 1 to 3 bars of added methane in the 330-450K temperature range. A formalism for the absorptivity of ammonia broadened by methane has now been developed and had been applied to the Hanley et al. (Icarus, v. 202, 2009) model for the opacity of ammonia. Due to methane's relatively low abundance at Jupiter (~0.2% by volume), its effect on the microwave spectrum which will be observed by the Juno MWR (Microwave Radiometer) will be minimal. However, these experimental results will significantly improve the understanding of the microwave emission spectrum of Uranus and Neptune where methane plays a more dominant role.

This thesis consists of four independent essays grouped in two parts. The first part analyzes the possibility and duration of a Pareto-improving pension reform. The second part considers some economic issues related to the tax avoidance activities. The possibility and duration of a Pareto-improving pension reform.Many countries face large problems in supporting current pay-as-you-go pension systems arising from demographic changes leading to the situation when returns on capital exceed population growth. Inefficiency arises from implicit taxation on pension contributions. In a closed economy, it is even more destructive due to its negative impact on savings and capital accumulation. Although the transition to a fully funded system is a great improvement of the economy, its implementation entails several difficulties if Pareto-efficiency is required. The first essay, “The Possibility of a Pareto Improving Pension Reform in a Heterogeneous Economy”, demonstrates that Pareto-improving transitions from pay-as-you-go to fully funded pension systems nearly always exist. To demonstrate this, I classify existing theoretical results according to the type of reformed economy, the form of pension benefits, and the policy instruments used during the transition. Then, I show that intergenerational heterogeneity should no longer be considered as an obstacle when implementing Pareto-improving pension reforms. To maintain redistributive or insurance mechanisms supported by pay-as-you-go systems, I propose to replace inefficient social security with redistributive tax and transfer payments inside one generation. This would save the economy from the inefficiency related to the implicit taxes on pension contributions imposed by pay-as-you-go systems. The second essay, “Designing Optimal Pareto Improving Pension Reforms: A More Distorted Economy Can be Reformed Faster”, investigates the optimal Pareto-improving debt-financed transition from pay-as-you-go to fully funded pension systems. In particular, I examine the relationship between key parameter values characterizing the preferences, the technology and the size of the initial system, and the necessary time for a Pareto-improving transition. My finding is that a more distorted economy can be reformed faster. This result gives an additional explanation to the success of the Chilean reform, where an initial pay-as-you-go system was the largest and, at the same time, the most distorting.An Economy with Clever Tax Avoidance Providers.In the third essay “The Importance of Income Distribution for the Price of the Tax Avoidance Service”, I design a model with a clever tax avoidance provider, who maximizes a profit by setting the price for the tax avoidance services. Therefore, the price for the tax avoidance service is endogenously defined. In that setup, the change in income distribution is not less important than changes in the tax code, which together are responsible for the tax avoidance demand. The model has a wide range of applications. In particular, I analyze the relation between inequality and the collection of tax revenue. The paper shows that tax revenue as a percentage of GDP might grow with inequality when the tax code is not significantly changed. Moreover, higher inequality implies lower marginal cost of additional revenue. This assay also considers tax base broadening, providing examples where this leads to a reduction in tax revenue.In the fourth essay, “ Tax Avoidance as a Reason for Secession”, I provide an additional explanation for the intentions to secede related to expected changes in the tax codes after the ''break down of a nation''. To demonstrate my points, I use a tax avoidance model designed in the third essay, where active tax avoidance providers make a decision about the price and quantity of their services. Secession gives the avoidance provider the option of setting different prices in separate regions.  As a consequence, the price for the tax avoidance service may fall in the poorer region and the elite of this region would be able to avoid the tax, which is impossible in union. Moreover, regional separation may lead to tremendous changes in the shape of income distribution, forcing new governments to change the tax codes. Thus, the government of the richer region may reduce tax rates in order to enlarge the tax revenue collection. To avoid a breakdown of the state, the government should reduce inefficient spending and tax duties. Promoting democracy or increasing the political influence of poor households may reduce the tendency to separate. / Diss. Stockholm : Handelshögskolan, 2002

Diss. Stockholm : Handelshögskolan, 2002.

Fifty years after the discovery of the first pulsating neutron star, the field of pulsar science has grown into a multidisciplinary research field, working to address a wide range of problems in astrophysics - from stellar evolution models to high precision tests of General Relativity to analysing the detailed structure of the Interstellar Medium in the Milky Way. Over 2500 Galactic pulsars have been discovered. The next generation telescopes, such as the Square Kilometre Array, promise to discover the complete observable Milky Way population, of several tens of thousands, over the next decade. These point sources in the sky have extreme properties, with matter densities comparable to that of an atomic nucleus, and surface magnetic fields a trillion times stronger than Earth's magnetic field. Observationally, the most valuable property is their rotational stability - allowing us to anticipate and sum their beamed radio emission, as the pulsar spins around its axis, on millisecond to second timescales. The detected radio wave signals carry with them information of the ionised interstellar medium (IISM) paths they traveled along. The imprints reveal that the pulsar signals we detect travel along multiple paths. While the bulk of the emitted signal propagates along a straight line, we also receive delayed emission scattered through small angles, back into our line of sight. This scattering is caused by fluctuations in the free electron densities of the IISM. The impact of these inhomogeneities is exaggerated at low observing frequencies, where averaged pulsar profiles are observed to be broadened, and showcase exponential scattering tails characterised by a scattering timescale &gcy;. Simple theoretical models predict a power law dependence of &gcy; on frequency, with a spectral index &alpha; = 4. Despite these predictions, my analysis of pulsar data in this thesis, reveal a more complex frequency dependence on &gcy;. I investigate the scattering characteristics of a set of pulsars observed by the Low Frequency Array (LOFAR), at 110~MHz to 190~MHz. These data are ideal datasets for accurate studies of pulsar scattering, providing broad frequency bands at low frequencies. I find anomalously low power law spectral indices, &alpha;, describing the frequency dependence of &gcy;. These indices are likely due to anisotropic scattering mechanisms or small scattering clouds in the IISM. To conduct effective data analysis, I develop scattering fitting techniques by first analysing IISM effects on simulated pulsar data. I investigate the effects of two different types of scattering mechanisms, isotropic and anisotropic scattering, and consider each of their particular frequency-dependent impacts on pulsar data. The work on simulated data provides a robust fitting technique for extracting scattering parameters and a framework for the interpretation of the LOFAR data used in this study. The fitting technique simultaneously models scattering effects and standard frequency-dependent pulse profile evolution. I present results for 13 pulsars with simple pulse shapes, and find that &gcy;, associated with scattering by a single thin screen, has a power law dependence on frequency with &alpha; ranging from 1.50 to 4.0. My results show that extremely anisotropic scattering can cause low &alpha; measurements. The anomalous scattering properties can also be caused by the presence of small scattering clumps in the IISM, as opposed to the conventionally modelled large scattering screens. Evidence for both anisotropic scattering and small scattering clouds with high electron densities come from other areas of research. Indications of the anisotropic nature of the local IISM mostly come from high resolution pulsar scintillation analyses, while evidence for high density scattering clouds is often based on extreme scattering events measured through quasar observations. My results suggest that these anomalous scattering properties are more prevalent than formerly thought, prompting us to reconsider the physical conditions of the IISM, where traditionally high electron densities are reserved for H_II regions and anisotropy is not modelled. High quality, low frequency pulsar data, where anomalous propagation effects become measurable, are a valuable addition in assisting us to distinguish between the different physical mechanisms that can be at play. The more complex these IISM characteristics reveal themselves to be, the harder it will be to disentangle intrinsic profile emission from IISM propagation imprints. Successfully separating these effects, however, promises to improve our understanding of the intrinsic pulsar radio emission - a process that is still poorly understood.

Semantic typology and categorization are important fields of research in linguistics. The aim of our work is to inspect these fields in regard to bilingualism. In this thesis we examine semantic categorization of body parts among four different groups of people: monolingual English speakers, monolingual Russian speakers, bilingual Russian speakers answering in English and bilingual Russian speakers answering in Russian. The hierarchies, ambiguities in naming patterns and homology were in the center of this study. The groups were also compared to each other in order to observe the effects of the first language learned (L1) and the second language learned (L2) on bilinguals. The results showed that Russian L1 bilinguals answering the Russian questionnaire displayed the same results as the Russian monolinguals, indicating a lack of influence from the L2. The Russian L1 bilinguals answering the English questionnaire used a semantic categorization most similar to their L1 and also demonstrated a broadening of the semantic categories related to neither the L1 nor the L2.

No description available.

本研究では、低粒子エネルギー領域における金属表面からの反射水素原子を水素原子バルマーアルファ（Hα）発光ドップラー分光計測によって検出する実験系を構築し、ヘリウムによるタングステン表面の微細構造化が水素粒子反射特性に与える影響を調査した。表面構造を持たないタングステンと比較して、Fuzz構造をもつタングステン試料では200 - 300 eVの入射粒子エネルギー領域にて粒子反射係数が1/2程度まで減少することが明らかになった。 / In this study, the author developed a measurement technique to detect hydrogen atoms reflected from a metal surface based upon the Doppler-spectroscopy of hydrogen Balmer-(Hα) emission. The developed measurement technique is a promising method to investigate the hydrogen particle reflection properties in low incident particle energy range, which has been considered difficult. The author applied the developed method into practice to clarify the effects of helium (He) induced tungsten (W) surface nanostructure upon the low energy hydrogen particle reflection. A W-fuzz sample was found to reduce the particle reflection coefficient by 1/2 of the flat reference W surface in low incident particle energy range of 200-300 eV. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University

Efforts to increase the participation of groups historically underrepresented in computing studies, and in the computing workforce, are well documented. It is a national effort with funding from a variety of sources being allocated to research in broadening participation in computing (BPC). Many of the BPC efforts are funded by the National Science Foundation (NSF) but as existing literature shows, the growth in representation of traditionally underrepresented minorities and women is not commensurate to the efforts and resources that have been directed toward this aim. Instead of attempting to tackle the barriers to increasing representation, this dissertation research tackles the underrepresentation problem by identifying what has worked (leveraging existing real-world data) to increase representation. This work studies the educational pathways of persons who have successfully transitioned into the computing workforce and identifies the common roadmaps that have contributed to retention, persistence, and success in attaining computing employment. Descriptive statistics, Logistic regression, Classification algorithms, Clustering, and Predictive analytics were employed, using the Stata statistical tool and Orange Data Mining tool on real-world data, to identify educational pathways that have resulted in successful employment outcomes for women and blacks in computing. The results of this analysis have highlighted key information that is capable of informing future “Broadening Participation in Computing” (BPC) efforts. This is because the information will enable researchers and decision makers to have a clearer picture of what educational choices have resulted in favorable outcomes for underrepresented minorities and women in computing; and consequently, researchers and decision makers would be able to more accurately target their BPC efforts to achieve optimal results. This knowledge can also be applied in career advising for young students who are trying to chart their path into computing, providing insight into alternative pathways.