Solvation dynamics in liquid water: III: energy fluxes and structural changes

In previous installments it has been shown how a detailed analysis of energy fluxes induced by electronic excitation of a solute can provide a quantitative understanding of the dominant molecular energy flow channels characterizing solvation—and in particular, hydration— relaxation dynamics. Here this work and power approach is complemented with a detailed characterization of the changes induced by such energy fluxes. We first examine the water solvent’s spatial and orientational distributions and the assorted energy fluxes in the various hydration shells of the solute to provide a molecular picture of the relaxation. The latter analysis is also used to address the issue of a possible “inverse snowball” effect, an ansatz concerning the time scales of the different hydration shells to reach equilibrium. We then establish a link between the instantaneous torque, exerted on the water solvent neighbors’ principal rotational axes immediately after excitation and the final energy transferred into those librational motions, which are the dominant short-time energy receptor.Postprint (author's final draft

Protection of the 13 T Nb3Sn Fresca II dipole

The EuCARD project aims on construction of a 19 T hybrid dipole; it will be made of a 6 T HTS dipole associated to a 13 T outsert Nb3Sn dipole [1]. This paper reviews the quench analysis and protection of the 13 T Nb3Sn dipole.Comment: 5 pages, Contribution to WAMSDO 2013: Workshop on Accelerator Magnet, Superconductor, Design and Optimization; 15 - 16 Jan 2013, CERN, Geneva, Switzerlan

Some considerations for various positioning systems and their science capabilities

Containerless processing of materials at elevated temperatures is discussed with emphasis on high temperature chemistry, thermophysical properties, materials science, and materials processing. Acoustic and electromagnetic positioning of high temperature melts are discussed. Results from recent ground based experiments, including KC-135 testing of an acoustic levitator, are presented. Some current positioning technologies and the potential for enhancing them are considered. Further, a summary of these technologies and their science capabilities for the development of future experiments is given

The Influence of Social Agents on Learning, Developing, and Growing Through Athletic Participation: A Theory of Athlete Development

Sports can significantly influence the lives of those who play them. Psychosocial outcomes such as values, skills, self-esteem, and goal setting are some of the referenced benefits associated with playing sports and are the result of athletes being exposed to situations in an environment that is favorable to learning. Due to the abundant nature of sports in the United States, there is a growing need to understand how to effectively create environments that are conducive to positive outcomes. However, such results and experiences are often anecdotally supported rather than scientifically driven. Therefore, the purpose of this dissertation was two-fold. First, it looked to develop and validate a reliable measure (i.e., Learned Lessons in Sport; LLS) to assess athlete’s perceptions that participating in sports led to their learning of valuable skills that transcend the sporting context. Second, it attempts to provide an empirical explanation and model to discern and assess how coaches’ communication affects a set of variables acting on learned lessons in sport. The designed measure and models serve to demonstrate the inherently communicative nature of sport and athlete development and identify the intersection of individual development and human growth that is the effect of playing sports. Using factor analytic techniques and serial mediation, three studies were conducted. Results of Study One (N = 207) and Study Two (N = 206), via exploratory factor analytics and confirmatory factor analytics, successfully developed and validated the LLS scale that assesses an athlete’s perception of their learning lessons through sport. The third study (N = 636) proposed and tested a model to demonstrate how coaches’ communication significantly affects a set of variables, such as values, orientation, and attitudes, that act on learned lessons via serial mediation. Results of Study Three support the proposed relationships but the data was not an overall good fit for the model and a revised model is proposed. Overall, this dissertation contributes to the growing field of sport communication and provides implications for stakeholders invested in creating meaningful environments for athletes to compete in

Examples of Berezin-Toeplitz Quantization: Finite sets and Unit Interval

We present a quantization scheme of an arbitrary measure space based on overcomplete families of states and generalizing the Klauder and the Berezin-Toeplitz approaches. This scheme could reveal itself as an efficient tool for quantizing physical systems for which more traditional methods like geometric quantization are uneasy to implement. The procedure is illustrated by (mostly two-dimensional) elementary examples in which the measure space is a $N$-element set and the unit interval. Spaces of states for the $N$-element set and the unit interval are the 2-dimensional euclidean $\R^2$ and hermitian \C^2 planes

Theory of correlations between ultra-cold bosons released from an optical lattice

In this paper we develop a theoretical description of the correlations between ultra-cold bosons after free expansion from confinement in an optical lattice. We consider the system evolution during expansion and give criteria for a far field regime. We develop expressions for first and second order two-point correlations based on a variety of commonly used approximations to the many-body state of the system including Bogoliubov, meanfield decoupling, and particle-hole perturbative solution about the perfect Mott-insulator state. Using these approaches we examine the effects of quantum depletion and pairing on the system correlations. Comparison with the directly calculated correlation functions is used to justify a Gaussian form of our theory from which we develop a general three-dimensional formalism for inhomogeneous lattice systems suitable for numerical calculations of realistic experimental regimes.Comment: 18 pages, 11 figures. To appear in Phys. Rev. A. (few minor changes made and typos fixed

Closed Spaces in Cosmology

This paper deals with two aspects of relativistic cosmologies with closed (compact and boundless) spatial sections. These spacetimes are based on the theory of General Relativity, and admit a foliation into space sections S(t), which are spacelike hypersurfaces satisfying the postulate of the closure of space: each S(t) is a 3-dimensional, closed Riemannian manifold. The discussed topics are: (1) A comparison, previously obtained, between Thurston's geometries and Bianchi-Kantowski-Sachs metrics for such 3-manifolds is here clarified and developed. (2) Some implications of global inhomogeneity for locally homogeneous 3-spaces of constant curvature are analyzed from an observational viewpoint.Comment: 20 pages, 6 figures, revised version of published paper. In version 2: several misprints corrected, 'redshifting' in figures improved. Version 3: a few style corrections; couple of paragraphs in subsection 2.4 rewritten. Version 4: figures 5 and 6 corrrecte

Universality class of quantum criticality in the two-dimensional Hubbard model at intermediate temperatures (t2/U≪T≪tt^2/U\ll T\ll t)

We show that the dilute Fermi gas quantum critical universality class quantitatively describes the Mott/metal crossover of the two-dimensional Hubbard model for temperatures somewhat less than (roughly half) the tunneling but much greater than (roughly twice) the superexchange energy. We calculate the observables expected to be universal near the transition --- density and compressibility --- with numerically exact determinantal quantum Monte Carlo. We find they are universal functions of the chemical potential. Despite arising from the strongly correlated regime of the Hubbard model, these functions are given by the weakly interacting, dilute Fermi gas model. These observables and their derivatives are the only expected universal static observables of this universality class, which we also confirm by verifying there is no scaling collapse of the kinetic energy, fraction of doubly occupied sites, and nearest neighbor spin correlations. Our work resolves the universality class of the intermediate temperature Mott/metal crossover, which had alternatively been proposed to be described by more exotic theories. However, in the presence of a Zeeman magnetic field, we find that interplay of spin with itinerant charge can lead to physics beyond the dilute Fermi gas universality class.Comment: Main text: 4 pages, 2 figures (6 panels). Supplementary info.: 2 pages, 3 figures (7 panels

Magnetization vector in the reversible region of a highly anisotropic cuprate superconductor: anisotropy factor and the role of 2D vortex fluctuations

By using a high quality Tl2Ba2Ca2Cu3O10 (Tl-2223) single crystal as an example, the magnetization vector was probed in the reversible region of highly anisotropic cuprate superconductors. For that, we have measured its components along and transverse to the applied magnetic field for different crystal orientations. The analysis shows that the angular dependence of the perpendicular component of the magnetization vector follows the one predicted by a London-like approach which includes a contribution associated with the thermal fluctuations of the 2D vortex positions. For the Tl-2223 crystal studied here, a lower bound for the anisotropy factor was estimated to be about 190.Comment: 6 pages, 3 figure