Construction of SU(3) irreps in canonical SO(3)-coupled bases

Alternative canonical methods for defining canonical SO(3)-coupled bases for SU(3) irreps are considered and compared. It is shown that a basis that diagonalizes a particular linear combination of SO(3) invariants in the SU(3) universal enveloping algebra gives basis states that have good $K$ quantum numbers in the asymptotic rotor-model limit.Comment: no figure

An equations-of-motion approach to quantum mechanics: application to a model phase transition

We present a generalized equations-of-motion method that efficiently calculates energy spectra and matrix elements for algebraic models. The method is applied to a 5-dimensional quartic oscillator that exhibits a quantum phase transition between vibrational and rotational phases. For certain parameters, 10 by 10 matrices give better results than obtained by diagonalising 1000 by 1000 matrices.Comment: 4 pages, 1 figur

What can co-speech gestures in aphasia tell us about the relationship between language and gesture?: A single case study of a participant with Conduction Aphasia

Cross-linguistic evidence suggests that language typology influences how people gesture when using ‘manner-of-motion’ verbs (Kita 2000; Kita & Özyürek 2003) and that this is due to ‘online’ lexical and syntactic choices made at the time of speaking (Kita, Özyürek, Allen, Brown, Furman & Ishizuka, 2007). This paper attempts to relate these findings to the co-speech iconic gesture used by an English speaker with conduction aphasia (LT) and five controls describing a Sylvester and Tweety1 cartoon. LT produced co-speech gesture which showed distinct patterns which we relate to different aspects of her language impairment, and the lexical and syntactic choices she made during her narrative

Fast and robust two-qubit gates for scalable ion trap quantum computing

We propose a new concept for a two-qubit gate operating on a pair of trapped ions based on laser coherent control techniques. The gate is insensitive to the temperature of the ions, works also outside the Lamb-Dicke regime, requires no individual addressing by lasers, and can be orders of magnitude faster than the trap period

Implementing Indigenous Ways of Knowing into Research: Insights into the Critical Role of Dreams as Catalysts for Knowledge Development

This research project expressed a Muskego Inninuwuk methodology as a foundation to explore experiences of individuals who possess both Indigenous and non-Indigenous ancestry in the development of their identities. The overall goal of this research was to create a space for individuals to express the impacts of systems, relationships and the ways in which people come to understand their overall wellbeing and connection to ancestors through stories in personal identity development. As an Indigenous researcher engaging with a Muskego Inninuwuk methodology meant that a foundational mechanism for knowledge development included inner knowing and dreaming; this article describes the process and experiences as a result of incorporating Indigenous ways of knowing. In this way, Indigenous research methodologies are catalysts toward healing, decolonization and resurgence

An exactly solvable model of a superconducting to rotational phase transition

We consider a many-fermion model which exhibits a transition from a superconducting to a rotational phase with variation of a parameter in its Hamiltonian. The model has analytical solutions in its two limits due to the presence of dynamical symmetries. However, the symmetries are basically incompatible with one another; no simple solution exists in intermediate situations. Exact (numerical) solutions are possible and enable one to study the behavior of competing but incompatible symmetries and the phase transitions that result in a semirealistic situation. The results are remarkably simple and shed light on the nature of phase transitions.Comment: 11 pages including 1 figur

Wind Integration into Various Generation Mixtures

A load balance model is used to quantify the economic and environmental effects of integrating wind power into three typical generation mixtures. System operating costs over a specified period are minimized by controlling the operating schedule of existing power generating facilities for a range of wind penetrations. Unlike other studies, variable generator efficiencies, and thus variable fuel costs, are taken into account, as are the ramping constraints on thermal generators. Results indicate that system operating cost will increase by 15% to 110% (pending generation mixture) at a wind penetration of 100% of peak demand. Results also show that some mixtures will exhibit cost reductions on the order of 13% for moderate wind penetrations and high wind farm capacity factors. System emissions also decrease by 13% to 32% (depending on generation mixture) at a wind penetration of 100%. This leads to emission abatement costs in the range of $65 per tonne-CO2e for coal dominated mixtures, but$450 per tonne-CO2e for hydro dominated mixtures. For natural gas dominated mixtures, the introduction of wind power may well be beneficial overall.Wind power integration, generation mixtures, emissions cost

Network Constrained Wind Integration: An Optimal Cost Approach

Planning electricity supply is important because power demand continues to increase while there is a concomitant desire to increase reliance on renewable sources. Extant research pays particular attention to highly variable, low-carbon energy sources such as wind and small-scale hydroelectric power. Models generally employ only a simple load levelling technique, ensuring that generation meets demand in every period. The current research considers the power transmission system as well as load levelling. A network model is developed to simulate the integration of highly variable non-dispatchable power into an electrical grid that relies on traditional generation sources, while remaining within the network’s operating constraints. The model minimizes a quadratic cost function over two periods of 336 hours, with periods representing low (summer) and high (winter) demand, subject to various linear constraints. The model is numerically solved using Matlab and GAMS software environments. Results indicate that, even for a grid heavily dependent on hydroelectricity, the addition of wind power can create difficulties, with system costs increasing with wind penetration, sometimes significantly.Electric networks, optimal power flow, wind power, intermittent sources

Estimates of primary production sources to Arctic bivalves using amino acid stable carbon isotope fingerprinting

Thesis (M.S.) University of Alaska Fairbanks, 2018Benthic invertebrates are a crucial trophic link in Arctic marine food webs. However, estimates of the contribution of primary production sources sustaining these organisms are not well characterized. Potential sources could include sinking particulate organic matter from sea ice algae and phytoplankton, terrestrial organic matter eroded from the coastal environment, macroalgal material, or microbial organic matter. Proportions of these sources could also be significantly altered in the future as a result of environmental change. We measured the stable carbon isotope values of essential amino acids in muscle tissue from two common bivalve genera (Macoma spp. and Astarte spp.) collected in Hanna Shoal in the northeastern Chukchi Sea, considered an Arctic benthic hotspot. We used stable isotope mixing models in R (simmr) to compare the stable carbon isotope amino acid fingerprints of the bivalves to a suite of amino acid source endmembers, including marine phytoplankton, brown and red macroalgae, bacteria, and terrestrial plants, to estimate the proportional contributions of primary production sources to the bivalve species from Hanna Shoal. The models revealed relatively high contributions of essential amino acids from phytoplankton and bacteria averaged across both species in the region as a whole. We also examined whether stable carbon isotope fingerprints could be measured from essential amino acids preserved in bivalve shells, which could then allow proportional contributions of food sources to be estimated from ancient bivalve shells, allowing source estimates to be extended back in time. To investigate this, we measured the stable carbon isotope values of essential amino acids in a suite of paired modern bivalve shells and muscle from Macoma calcarea from the Chukchi Sea. These analyses revealed a correspondence between the fingerprints and mixing model estimates of the dominant primary production source of essential amino acids derived from analyses of these two tissue types. Our findings indicate that stable carbon isotope amino acid fingerprinting of marine bivalves can be used to examine dominant organic matter sources in the Arctic marine benthos in recent years as well as in deeper time.Coastal Marine Institute, Bureau of Ocean Energy Management (Cooperative Agreement number M16AC00005

Schools Respond to Risk Management Programs for Asbestos, Lead in Drinking Water and Radon

Based on a study of the three EPA-initiated, public school risk management programs noted in the title, the authors find that state agency involvement is an important factor in the success of such programs. They also find, e.g., that school districts are justifiably reluctant to comply with tentative program