Octahedral molybdenum cluster complexes with aromatic sulfonate ligands

This article describes the synthesis, structures and systematic study of the spectroscopic and redox properties of a series of octahedral molybdenum metal cluster complexes with aromatic sulfonate ligands (nBu4N)2[{Mo6X8}(OTs)6] and (nBu4N)2[{Mo6X8}(PhSO3)6] (where X- is Cl-, Br- or I-; OTs- is p-toluenesulfonate and PhSO3 - is benzenesulfonate). All the complexes demonstrated photoluminescence in the red region and an ability to generate singlet oxygen. Notably, the highest quantum yields (>0.6) and narrowest emission bands were found for complexes with a {Mo6I8}4+ cluster core. Moreover, cyclic voltammetric studies revealed that (nBu4N)2[{Mo6X8}(OTs)6] and (nBu4N)2[{Mo6X8}(PhSO3)6] confer enhanced stability towards electrochemical oxidation relative to corresponding starting complexes (nBu4N)2[{Mo6X8}X6]

Adjusted intensity nonlocal diffusion model of photopolymer grating formation

Diffusion-based models of grating formation in photopolymers have been proposed in which the rate of monomer polymerization (removal) is directly proportional to the illuminating intensity inside the medium. However, based on photochemical considerations, the rate of polymerization is proportional in the steady state to the square root of the interference intensity. Recently it was shown that, by introducing a nonlocal response function into the one-dimensional diffusion equation that governs holographic grating formation in photopolymers, one can deduce both high-frequency and low-frequency cutoffs in the spatial-frequency response of photopolymer materials. Here the first-order nonlocal coupled diffusion equations are derived for the case of a general relationship between the rate of polymerization and the exposing intensity. Assuming a twoharmonic monomer expansion, the resultant analytic solutions are then used to fit experimental growth curves for gratings fabricated with different spatial frequencies. Various material parameters, including monomer diffusion constant D and nonlocal variance s, are estimated.Not applicablepe, la, sp, ke, ab, is, en - kpw8/11/1

Akrotiri Aetokremnos and the Cypriot Pygmy Hippopotamus: An Interdisciplinary Look at a Late Pleistocene Large Mammal Extinction

Thesis (Ph.D.)--University of Washington, 2015The cause for large mammal extinctions in the Late Pleistocene has been debated for decades, with two main factors constantly discussed--human hunting and climatic change. The Cypriot pygmy hippopotamus represents a case study of one such extinction event. The last appearance of this species is at the archaeological site Akrotiri Aetokremnos (~12,000 cal. B.P.), the oldest well-dated site on Cyprus. This dissertation represents interdisciplinary analyses surrounding the faunal remains of the Cypriot pygmy hippopotamus at this site, in an attempt to create a more holistic picture of the dynamics of this event and parse out the potential relative impacts of climate change and humans. First, a morphological comparison between other extinct and extant hippopotamids allows the inferences of the behavior and subsistence strategies of the Cypriot pygmy hippopotamus. This is then correlated with the Late Pleistocene climatic change, and documented through stable isotope studies from the Cypriot pygmy hippopotamus remains, showing that this species would have been susceptible to such dramatic change. After the discussion of this paleoecological context, the archaeological site is evaluated for any evidence of post-depositional taphonomic processes which could potentially skew the representation of faunal remains--creating biases. Next, comparing the demographic profiles at Akrotiri Aetokremnos to theoretical and ecological profiles shows compelling evidence that humans hunted this species. With this in mind, a detailed assessment of the skeletal representation at the site allows the inference of human behavior--attempting to identify how humans may have procured and/or utilized this species. Overall, this work sheds light on this species' dynamics, the nature of accumulation at this particular site, and begins the discussion of how the earliest Cypriots may have procured and interacted with the species

Akrotiri Aetokremnos faunal data

<p>Raw data and statistical analyses presented in doctoral dissertation "Akrotiri <em>Aetokremnos</em> and the Cypriot Pygmy Hippopotamus: An Interdisciplinary Look at a Late Pleistocene Large Mammal Extinction" and resulting papers.</p