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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Structural determination of complex anionic oligosaccharides by mass spectrometry

Wheeler, Susan F. January 2000 (has links)
No description available.
2

An Analysis of Risk Neutral Strategies in Taiwanese Stock Markets

Su, Yu-Fang 10 August 2007 (has links)
Risk neutral strategies emphasize stock selection rather than market timing in order to achieve the objective of a positive abnormal return. Using CAPM and Fama-French three-factor models as benchmark, this study applies the risk neutral strategies to Taiwanese stock markets. Empirical results reveal that R-square of Fama-French 3-factor model is higher than that of CAPM, implying that Fama-French model outperforms CAPM in explaining the stock returns in our sample. In addition, Portfolios 1 and 2 generate significantly positive abnormal returns. We conclude that risk neutral strategies offer positive abnormal returns.
3

Semiquinone-Bridged bis-Dithiazolyls as Neutral Radical Conductors

Yu, Xin January 2011 (has links)
Radicals are potential building blocks to prepare conductive and magnetic materials. In order to achieve high conductivity, materials displaying a large bandwidth W and a low on-site Coulomb repulsion energy U must be generated. Semiquinone-bridged bis-1,2,3-dithiazolyl radicals (R = Cl, Ph, Me and the MeCN adduct of R = Cl) represent a new family of resonance stabilized neutral radical for use in the design of single-component conductive materials were prepared and fully characterized. In solid state these radicals remain as unassociated (monomers) in the solid state and typically form superimposed alternating π-stacks or slipped π-stacks, arranged in several different space groups. The predominate intermolecular interactions are S•••N′ and / or S•••O′ contacts, which increase the dimensionality from one dimensional π-stacked systems (i.e., poor lateral overlap) to two dimensional systems in the solid state. Thus the semiquinone-bridged bis-dithiazolyl radicals exhibit a significant decrease in activation energy (ca. 0.1 – 0.2 eV) and the conductivity is two to three orders of magnitude (ca. σ ≈ 1E-5 – 1E-2 S / cm) higher in comparison to the previously reported pyridine based systems. This high conductivity is attributed to the low on-site Coulomb repulsion energies (U) which were estimated from the solution cell potentials (EPC) obtained from CV measurements and improved bandwidth (W) from the S•••N′ and / or S•••O′ interactions. Furthermore, the all sulphur containing semiquinone-bridged bis-dithiazolyls have the lowest activation energies and the highest conductivity under ambient conditions compared with other all sulfur nitrogen based radicals known to date. The semiquinone-bridged bis-dithiazolyl (R = Cl) orderes as spin-canted antiferromagnets, TN = 8 K, and displayed large coercivity (80 Oe). The ZFC-FC measurement at low field (i.e., H = 100 Oe) established the phase transition temperatures and the spontaneous magnetization was used to estimate the spin canting angles (~ 0.14°). In the case of R = Ph, the antiparallel alignment of the ferromagnetic coupled chains leads to a spin-canted antiferromagnet (TN = 4.5 K), which undergo a unique field induced spin flop transition. The MeCN solvated of R = Cl behaves as a simple paramagnet at room temperature with bulk antiferromagnetic interactions, but no observed magnetic ordering from 2-300 K.
4

Some Aspects of Neutral Systems: Stability Analysis and Stabilization

Fan, Kuo-Kuang 28 October 2002 (has links)
ABSTRACT In this dissertation, the stability analysis and stabilization problems of neutral systems are investigated. Firstly, the stability analysis of various classes of neutral systems, including discrete and distributed time-delay systems, are investigated by using Lyapunov functional approach. Delay-dependent and delay-independent criteria are proposed. Secondly, we consider the stability problems of neutral systems by using the powerful LMI tools. In this part, we also provide delay-dependent and delay-independent criteria for the stability of neutral systems under consideration. Finally, the stabilization problems of neutral systems are considered. We will propose stabilizability criteria for neutral systems with multiple time delays and with input delay, respectively. We will provide an observer-based controller design method. The improvements of our results over those results recently published in related literature are illustrated if the comparisons are possible. Examples are given in appropriate places to illustrate our main results.
5

The impact of anti-affirmative action lawsuits : a case study of The University of Texas School of Law from 1996 to 2003

Riley, Samuel Ray 16 February 2015 (has links)
Educational Administration / This study analyzes the effects race-neutral admissions policies have on a large predominantly white law school through the lens of its administrators and alumni. Previously, this law school relied on race conscious admissions policies to help it increase and maintain diversity. Utilizing historical documents and relevant stakeholder interviews from prominent former students and staff, in addition to current faculty and staff, I hope to provide a blueprint for other law schools to follow during a race-neutral admissions environment. This is especially relevant with affirmative action policies threatened by state voter referendums, executive orders, and legislation. / text
6

Semiquinone-Bridged bis-Dithiazolyls as Neutral Radical Conductors

Yu, Xin January 2011 (has links)
Radicals are potential building blocks to prepare conductive and magnetic materials. In order to achieve high conductivity, materials displaying a large bandwidth W and a low on-site Coulomb repulsion energy U must be generated. Semiquinone-bridged bis-1,2,3-dithiazolyl radicals (R = Cl, Ph, Me and the MeCN adduct of R = Cl) represent a new family of resonance stabilized neutral radical for use in the design of single-component conductive materials were prepared and fully characterized. In solid state these radicals remain as unassociated (monomers) in the solid state and typically form superimposed alternating π-stacks or slipped π-stacks, arranged in several different space groups. The predominate intermolecular interactions are S•••N′ and / or S•••O′ contacts, which increase the dimensionality from one dimensional π-stacked systems (i.e., poor lateral overlap) to two dimensional systems in the solid state. Thus the semiquinone-bridged bis-dithiazolyl radicals exhibit a significant decrease in activation energy (ca. 0.1 – 0.2 eV) and the conductivity is two to three orders of magnitude (ca. σ ≈ 1E-5 – 1E-2 S / cm) higher in comparison to the previously reported pyridine based systems. This high conductivity is attributed to the low on-site Coulomb repulsion energies (U) which were estimated from the solution cell potentials (EPC) obtained from CV measurements and improved bandwidth (W) from the S•••N′ and / or S•••O′ interactions. Furthermore, the all sulphur containing semiquinone-bridged bis-dithiazolyls have the lowest activation energies and the highest conductivity under ambient conditions compared with other all sulfur nitrogen based radicals known to date. The semiquinone-bridged bis-dithiazolyl (R = Cl) orderes as spin-canted antiferromagnets, TN = 8 K, and displayed large coercivity (80 Oe). The ZFC-FC measurement at low field (i.e., H = 100 Oe) established the phase transition temperatures and the spontaneous magnetization was used to estimate the spin canting angles (~ 0.14°). In the case of R = Ph, the antiparallel alignment of the ferromagnetic coupled chains leads to a spin-canted antiferromagnet (TN = 4.5 K), which undergo a unique field induced spin flop transition. The MeCN solvated of R = Cl behaves as a simple paramagnet at room temperature with bulk antiferromagnetic interactions, but no observed magnetic ordering from 2-300 K.
7

HI 21cm absorbers at moderate redshifts

Lane, Wendy Meredith, January 2000 (has links)
Thesis (Doctoral)--Rijsuniversiteit Groningen, 2000. / Includes bibliographical references.
8

Gas flow measurements of a novel geometry for neutral beam neutralizers

Pirkle, David Ross. January 1984 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 139-141).
9

Spectral analysis of neutral evolution

Shorten, David January 2017 (has links)
It has been argued that much of evolution takes place in the absence of fitness gradients. Such periods of evolution can be analysed by examining the mutational network formed by sequences of equal fitness, that is, the neutral network. It has been demonstrated that, in large populations under a high mutation rate, the population distribution over the neutral network and average mutational robustness are given by the principal eigenvector and eigen- value, respectively, of the network's adjacency matrix. However, little progress has been made towards understanding the manner in which the topology of the neutral network influences the resulting population distribution and robustness. In this work, we build on recent results from spectral graph theory and utilize numerical methods to enhance our understanding of how populations distribute themselves over neutral networks. We demonstrate that, in the presence of certain topological features, the population will undergo an exploration catastrophe and become confined to a small portion of the network. We further derive approximations, in terms of mutational biases, for the population distribution and average robustness in networks with a homogeneous structure. The applicability of these results is explored, first, by a detailed review of the literature in both evolutionary computing and biology concerning the structure of neutral networks. This is extended by studying the actual and predicted population distribution over the neutral networks of H1N1 and H3N2 influenza haemagglutinin during seasons between 2005 and 2016. It is shown that, in some instances, these populations experience an exploration catastrophe. These results provide insight into the behaviour of populations on neutral networks, demonstrating that neutrality does not necessarily lead to an exploration of genotype/phenotype space or an associated increase in population diversity. Moreover, they provide a plausible explanation for conflicting results concerning the relationship between robustness and evolvability.
10

Passive Stiffness Characteristics of the Scoliotic Lumbar Torso in Trunk Flexion, Extension, Lateral bending, and Axial Rotation

Voinier, Steven 08 May 2015 (has links)
As the average American age increases, there is a need to study the spine biomechanics of adults with scoliosis. Most studies examining the mechanics of scoliosis have focused on in vitro testing or computer simulations, but in vivo testing of the mechanical response of a scoliotic spine has not yet been reported. The purpose of this study was to quantitatively define the passive stiffness properties of the in vivo scoliotic spine in three principle anatomical motions and identify differences relative to healthy controls. Scoliotic (n=14) and control (n=17) participants with no history of spondylolisthesis, spinal fracture, or spinal surgery participated in three different tests (torso lateral side bending, torso axial rotation, and torso flexion/extension) that isolated mobility to the in vivo lumbar spine. Scoliotic individuals with Cobb angles ranging 15-75 degrees were accepted. Applied torque was measured using a uni-directional load cell, and inertial measurement units (IMU) recorded angular displacement of the upper torso relative to the pelvis and lower extremities. Torque-rotational displacement data were fit using a double sigmoid function, resulting in excellent overall fit (R2 > 0.901). The neutral zone (NZ) width, or the range of motion where there is minimal internal resistance, was then calculated. Stiffnesses within the NZ and outside of the NZ were also calculated. Stiffness asymmetries were also computed within each trial. These parameters were statistically compared between factor of population and within factor of direction. There was an interaction effect between populations when comparing axial twist NZ width and lateral bend NZ width. The lateral bend NZ width magnitude was significantly smaller in scoliotic patients. NZ stiffness in the all three directions was greater in the scoliotic population. There was no significant difference in asymmetrical stiffness between populations. The present study is the first investigation to quantify the in vivo neutral zone and related mechanics of the scoliotic lumbar spine. Future research is needed to determine if the measured lumbar spine mechanical characteristics can help explain progression of scoliosis and complement scoliosis classification systems. / Master of Science

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