Launch vehicle wind and turbulence response by nonstationary statistical methods

Nonstationary adjoint algorithm for determining launch vehicle flight loads due to winds and turbulenc

The Convective Urca Process with Implicit Two-Dimensional Hydrodynamics

Consideration of the role of the convective flux in the thermodymics of the convective Urca neutrino loss process in degenerate, convective, quasi-static, carbon-burning cores shows that the convective Urca process slows down the convective current around the Urca-shell, but, unlike the "thermal" Urca process, does not reduce the entropy or temperature for a given convective volume. Here we demonstrate these effects with two-dimensional numerical hydrodynamical calculations. These two-dimensional implicit hydrodynamics calculations invoke an artificial speeding up of the nuclear and weak rates. They should thus be regarded as indicative, but still qualitative. We find that, compared to a case with no Urca-active nuclei, the case with Urca effects leads to a higher entropy in the convective core because the energy released by nuclear burning is confined to a smaller volume by the effective boundary at the Urca shell. All else being equal, this will tend to accelerate the progression to dynamical runaway. We discuss the open issues regarding the impact of the convective Urca process on the evolution to the "smoldering phase" and then to dynamical runaway.Comment: 22 pages, 11 figures, accepted for publication in the Astrophysical Journa

Phase field modeling of electrochemistry II: Kinetics

The kinetic behavior of a phase field model of electrochemistry is explored for advancing (electrodeposition) and receding (electrodissolution) conditions in one dimension. We described the equilibrium behavior of this model in [J. E. Guyer, W. J. Boettinger, J.A. Warren, and G. B. McFadden, ``Phase field modeling of electrochemistry I: Equilibrium'', cond-mat/0308173]. We examine the relationship between the parameters of the phase field method and the more typical parameters of electrochemistry. We demonstrate ohmic conduction in the electrode and ionic conduction in the electrolyte. We find that, despite making simple, linear dynamic postulates, we obtain the nonlinear relationship between current and overpotential predicted by the classical ``Butler-Volmer'' equation and observed in electrochemical experiments. The charge distribution in the interfacial double layer changes with the passage of current and, at sufficiently high currents, we find that the diffusion limited deposition of a more noble cation leads to alloy deposition with less noble species.Comment: v3: To be published in Phys. Rev. E v2: Attempt to work around turnpage bug. Replaced color Fig. 4a with grayscale 13 pages, 7 figures in 10 files, REVTeX 4, SIunits.sty, follows cond-mat/030817

Corticosterone Regulates Both Naturally Occurring and Cocaine‐Induced Dopamine Signaling by Selectively Decreasing Dopamine Uptake

Stressful and aversive events promote maladaptive reward‐seeking behaviors such as drug addiction by acting, in part, on the mesolimbic dopamine system. Using animal models, data from our laboratory and others show that stress and cocaine can interact to produce a synergistic effect on reward circuitry. This effect is also observed when the stress hormone corticosterone is administered directly into the nucleus accumbens (NAc), indicating that glucocorticoids act locally in dopamine terminal regions to enhance cocaine\u27s effects on dopamine signaling. However, prior studies in behaving animals have not provided mechanistic insight. Using fast‐scan cyclic voltammetry, we examined the effect of systemic corticosterone on spontaneous dopamine release events (transients) in the NAc core and shell in behaving rats. A physiologically relevant systemic injection of corticosterone (2 mg/kg i.p.) induced an increase in dopamine transient amplitude and duration (both voltammetric measures sensitive to decreases in dopamine clearance), but had no effect on the frequency of transient release events. This effect was compounded by cocaine (2.5 mg/kg i.p.). However, a second experiment indicated that the same injection of corticosterone had no detectable effect on the dopaminergic encoding of a palatable natural reward (saccharin). Taken together, these results suggest that corticosterone interferes with naturally occurring dopamine uptake locally, and this effect is a critical determinant of dopamine concentration specifically in situations in which the dopamine transporter is pharmacologically blocked by cocaine

Understanding light quanta: First quantization of the free electromagnetic field

The quantization of the electromagnetic field in vacuum is presented without reference to lagrangean quantum field theory. The equal time commutators of the fields are calculated from basic principles. A physical discussion of the commutators suggest that the electromagnetic fields are macroscopic emergent properties of more fundamental physical system: the photons

Uncertainty Relation Revisited from Quantum Estimation Theory

By invoking quantum estimation theory we formulate bounds of errors in quantum measurement for arbitrary quantum states and observables in a finite-dimensional Hilbert space. We prove that the measurement errors of two observables satisfy Heisenberg's uncertainty relation, find the attainable bound, and provide a strategy to achieve it.Comment: manuscript including 4 pages and 2 figure

Social inclusion: Context, theory and practice

This paper reviews the literature on social inclusion in Australia and provides an overview of the current situation regarding university/community engagement. Social inclusion is a contested term in both academic and policy literature entailing a range of interpretations. The paper will argue that there is a spectrum of ideological positions underlying theory, policy and practice. The broad theoretical construct put forward regards social inclusion in relation to areas (who is to be included?) and degrees (ideologies) of inclusion. Possible areas of inclusion are socio‐economic status, culture (including indigenous cultures), linguistic group, religion, geography (rural and remote/isolated), gender, sexual orientation, age (including youth and old age), physical and mental health/ability, and status with regard to unemployment, homelessness and incarceration. Degree of inclusion comprises a nested threefold schema incorporating a spectrum of ideologies involving—from narrowest to most encompassing—the neoliberal focus on access and economic factors, the social justice focus on community participation and the human potential focus on personal and collective empowerment stemming from positive psychology and critical/transformative pedagogies. Contemporary Australian social inclusion policy is related to UK policy. While policy rhetoric indicates a broad interpretation of social inclusion, concerns are raised that a dominant Economicist agenda favours corporate and national economic interests over social and psychological ones. Questions are also raised about the privileging of some areas of inclusion over others and the possibility that reductive interpretations of social inclusion are forms of cultural assimilation. Social inclusion in practice is addressed both in relation to degrees of inclusion and through case studies. The paper provides an overview of examples of social inclusion interventions, including a review of two initiatives of RMIT University and Victoria University focussing on industry/community partnerships. The paper concludes with some challenges and issues for further research on social inclusion including a proposed in-depth survey and consideration of literature on integrative phenomena such as ecological sustainability, and contextualisation of social inclusion within broader movements of global socio‐cultural change