Are Democracies More or Less Likely to Abrogate Alliances?

This thesis examines the impact of democracy on alliance abrogation. It serves as an extension of the current literature that examines democratic commitments and merges that with alliance studies. The data used consists of alliances from 1816-1991 and has been composed using EUGene from Leeds and Anac (2005), Correlates of War, and Polity IV. Using a standard probit model, this thesis examines the relationship between democracy and alliance commitments in a systematic approach and finds little evidence to support existing theoretical justifications on how democracies behave in an alliance

Stellar or Non-Stellar Light? Determining Near-Infrared Contamination in Low Mass X-ray Binaries

Low-mass X-ray binary (LMXB) systems are comprised of a low-mass, K or M dwarflike star orbiting a compact object. Stellar black hole masses and their distributions are important inputs for binary evolution and supernova models. Currently, the main limiting factor in determining accurate black hole masses in LMXBs is the uncertainty of the orbital inclination angle due to an unknown amount of contaminating light in the near infrared. If present, this light dilutes the ellipsoidal variations of the low-mass secondary star, and thus gives the appearance of a lower orbital inclination system. It has been generally thought that the near infrared ellipsoidal light curves of these systems were relatively uncontaminated and represented primarily the light from the low-mass secondary star; however, recent disk and jet models have thrust this thinking into question. We combine our data from the Spitzer Space Telescope with our ground-based optical and near infrared data for several LMXBs to characterize and derive the amount of light contaminating the near-infrared ellipsoidal variations of the low-mass secondary star

An Excited-State-Specific Projected Coupled-Cluster Theory

We present an excited-state-specific coupled-cluster approach in which both the molecular orbitals and cluster amplitudes are optimized for an individual excited state. The theory is formulated via a projection of the traditional coupled-cluster wavefunction that allows correlation effects to be introduced atop an excited state mean field starting point. The approach shares much in common with ground state CCSD, including size consistency and an N^6 cost scaling. Preliminary numerical tests show that the method can improve over excited-state-specific second order perturbation theory in valence, charge transfer, and Rydberg states.Comment: 41 pages, 2 figures, 5 table

Aufbau Suppressed Coupled Cluster Theory for Electronically Excited States

We introduce an approach to improve single-reference coupled cluster theory in settings where the Aufbau determinant is absent from or plays only a small role in the true wave function. Using a de-excitation operator that can be efficiently hidden within a similarity transform, we create a coupled cluster wave function in which de-excitations work to suppress the Aufbau determinant and produce wave functions dominated by other determinants. Thanks to an invertible and fully exponential form, the approach is systematically improvable, size consistent, size extensive, and, interestingly, size intensive in a granular way that should make the adoption of some ground state techniques such as local correlation relatively straightforward. In this initial study, we apply the general formalism to create a state-specific method for orbital-relaxed singly excited states. We find that this approach matches the accuracy of similar-cost equation-of-motion methods in valence excitations while offering improved accuracy for charge transfer states. We also find the approach to be more accurate than excited-state-specific perturbation theory in both types of states.Comment: 16 pages, 4 tables, 1 figur

Properties and applications of polyether salt complexes

The physical properties of polyethers have been modified by complexation with inorganic salts. The cation is bound to the polyether oxygen atoms to produce a single phase polymer-salt solution. The salts chosen were generally from the alkali and alkaline earth metals but other salt systems were investigated. It was observed, using the technique of differential thermal analysis, that the complexes gave single, well defined, glass transitions which occurred at temperatures higher than the uncomplexed polymer. [Continues.

Ruled out: the use of cyclododecane as a temporary facing during the removal of a canvas lining from a fresco of a kneeling flagellant and Saints Michael and Stephen by Spinello Aretino

This paper is published in the book ‘Subliming Surfaces: Volatile Binding Media in Heritage Conservation’, ed. Christina Rozeik (University of Cambridge Museums, 2018), pp. 155-157.Three fragments of an early fifteenth-century Italian fresco, The Fall of Lucifer by Spinello Aretino, were presented to the National Gallery, London by Sir Henry Layard in 1886. They were detached from the wall above the high altar of Compagnia di Sant'Angelo, or S. Michele Arcangelo, in Arezzo by the strappo technique and lined onto canvas. Movement and shrinkage of the animal glue lining had caused buckling of the fresco, a long-term problem that led to losses from the fragments. A treatment programme to transfer the fragments to solid supports was proposed, using a facing of Japanese tissue paper applied with Klucel G and consolidation with cyclododecane (CDD) to strengthen the structure while the canvas was removed. However, the mordant securing the tin-leaf decoration was found to contain oil and sandarac resin, and there was uncertainty about the effect of prolonged immersion in PET (used to remove the CDD after treatment) on the mordant. The animal glue that holds much of the paint layer together, and some of the pigment binders, were also soluble in water, making the use of Klucel G inadvisable. The Klucel G facing was integral to the treatment plan, so the plan to remove the canvas was abandoned, also ruling out the use of CDD. As a result, the treatment proposal was reassessed in favour of retaining the canvas layer

Weak gravitational lensing with CO galaxies

Optical weak lensing surveys have become a powerful tool for precision cosmology, but remain subject to systematic effects that can severely bias cosmological parameter estimates if not carefully removed. We discuss the possibility of performing complementary weak lensing surveys at radio/microwave frequencies, using detections of CO-emitting galaxies with resolved continuum images from ngVLA. This method has completely different systematic uncertainties to optical weak lensing shear measurements (e.g. in terms of blending, PSF, and redshift uncertainties), and can provide additional information to help disentangle intrinsic alignments from the cosmological shear signal. A combined analysis of optical and CO galaxy lensing surveys would therefore provide an extremely stringent validation of highly-sensitive future surveys with Euclid, LSST, and WFIRST, definitively rejecting biases due to residual systematic effects. A lensing survey on ngVLA would also provide valuable spectral (kinematic) and polarimetric information, which can be used to develop novel cosmological analyses that are not currently possible in the optical.Comment: Contribution to 2018, ASP Conference Series Monograph 7, "Science with a Next-Generation Very Large Array," Eric Murphy, ed., in preparatio

ImpaCT2: pupils' and teachers' perceptions of ICT in the home, school and community

The Strand 2 report of the ImpaCT 2 research describes the results of applying a range of research methods to explore, how pupils use ICT, in particular out of school and what had been gained from this use. ImpaCT2 was a major longitudinal study (1999-2002) involving 60 schools in England, its aims were to: identify the impact of networked technologies on the school and out-of-school environment; determine whether or not this impact affected the educational attainment of pupils aged 8 - 16 years (at Key Stages 2, 3, and 4); and provide information that would assist in the formation of national, local and school policies on the deployment of ICT