A Semiclassical Derivation of the QCD Coupling

The measured value of the QCD coupling alpha(sub s) at the energy M(sub Zo), the variation of alpha(sub s) as a function of energy in QCD, and classical relativistic dynamics are used to investigate virtual pairs of quarks and antiquarks in vacuum fluctuations. For virtual pairs of bottom quarks and antiquarks, the pair lifetime in the classical model agrees with the lifetime from quantum mechanics to good approximation, and the action integral in the classical model agrees as well with the action that follows from the Uncertainty Principle. This suggests that the particles might have small de Broglie wavelengths and behave with well-localized pointlike dynamics. It also permits alpha(sub s) at the mass energy twice the bottom quark mass to be expressed as a simple fraction: 3/16. This is accurate to approximately 10%. The model in this paper predicts the measured value of alpha(sub s)(M(sub Zo)) to be 0.121, which is in agreement with recent measurements within statistical uncertainties

X-Ray Observations of Recurrence of Eruptive Flares and Active Regions

In a study of soft X-ray coronal images obtained with the Yohkoh spacecraft, two eruptive flares with remarkably similar X-ray structures were noted -- most remarkably because the flares occurred at the same solar location (approximately 10 degrees north latitude on the east limb) yet separated in time by three solar rotations. Between the times of the eruptions, the active region responsible for the first flare disappeared from Yohkoh images. An extremely similar X-ray active region replaced it by the third solar rotation. The recurring X-ray active region appearance and recurring flare activity after 86 days suggest that persistent subsurface flux emergence patterns might be responsible, and support previous arguments that 'active longitudes' exist

The Technological Progress of Malaysian Banks: An Empirical Investigation.

It is customary to argue that technological innovations result in productivity enhancement. This paper explores this issue in the context of the Malaysian banking sector which has been subject to enormous restructuring and technological innovations, inclusive of the introduction of e-banking. The provision of banking services through electronic delivery channels can be equated with the e-government initiatives. This study attempts to identify the contribution of e-banking and technological progress of Malaysian commercial banks by employing the Malmquist productivity index (MPI), whereby productivity growth amongst the banks is broken down into technical efficiency change, scale change and technological change. The sample includes all 10 domestic commercial banks in Malaysia over the period of 1997 to 2002. The principle findings indicate an overall rise in total productivity, driven by technological progress rather than scale change or technical efficiency change. Extending to e-government, the employment of high-end, state of the art information and communication technologies can facilitate efficient and effective delivery of government services through electronic delivery channels. The results, which detail the improvements achieved by the best practice bank, may provide useful insights for government regulators and management for policy formulation.Malmquist productivity index; technological progress; e-banking; productivity changes

Mass Spectrometry of Dendrimer Metal Complexes

Dendrimers are hyper-branched macromolecules with unique properties. They form using a “cascade-like” synthesis involving repetitive reaction steps. These steps are controlled, resulting in monodisperse dendrimers. Synthesis is divergent, core to exterior, or convergent, exterior to core. Dendrimers are created from various molecules with numerous functional properties. They are used as catalysts, diagnostic agents, and others. This thesis studies 1st generation poly(propylene) imine, consisting of a diaminobutane core with 4 propyl amine branches. Fragmentation of protonated and metal (Co, Ni, Cu and Zn) complexed dendrimers was analyzed by ion-trap mass spectrometry. Two isotopically labeled dendrimers were synthesized for neutral loss identification and possible fragmentation mechanisms. Protonated dendrimer fragments through substitution mechanisms. Similar fragments are identified in metal complexes, but the dendrimer is coordinated in a specific geometry with the metal and elimination mechanisms dominate. Fragmentation schemes for all complexes are presented. Neutral mass losses are compared and unique fragments discussed

Hamiltonian Cycles on Random Eulerian Triangulations

A random Eulerian triangulation is a random triangulation where an even number of triangles meet at any given vertex. We argue that the central charge increases by one if the fully packed O(n) model is defined on a random Eulerian triangulation instead of an ordinary random triangulation. Considering the case n -> 0, this implies that the system of random Eulerian triangulations equipped with Hamiltonian cycles describes a c=-1 matter field coupled to 2D quantum gravity as opposed to the system of usual random triangulations equipped with Hamiltonian cycles which has c=-2. Hence, in this case one should see a change in the entropy exponent from the value gamma=-1 to the irrational value gamma=(-1-\sqrt{13})/6=-0.76759... when going from a usual random triangulation to an Eulerian one. A direct enumeration of configurations confirms this change in gamma.Comment: 22 pages, 9 figures, references and a comment adde

Physics of Rheologically-Enhanced Propulsion: Different Strokes in Generalized Stokes

Shear-thinning is an important rheological property of many biological fluids, such as mucus, whereby the apparent viscosity of the fluid decreases with shear. Certain microscopic swimmers have been shown to progress more rapidly through shear-thinning fluids, but is this behavior generic to all microscopic swimmers, and what are the physics through which shear-thinning rheology affects a swimmer's propulsion? We examine swimmers employing prescribed stroke kinematics in two-dimensional, inertialess Carreau fluid: shear-thinning "Generalized Stokes" flow. Swimmers are modeled, using the method of femlets, by a set of immersed, regularized forces. The equations governing the fluid dynamics are then discretized over a body-fitted mesh and solved with the finite element method. We analyze the locomotion of three distinct classes of microswimmer: (1) conceptual swimmers comprising sliding spheres employing both one- and two-dimensional strokes, (2) slip-velocity envelope models of ciliates commonly referred to as "squirmers" and (3) monoflagellate pushers, such as sperm. We find that morphologically identical swimmers with different strokes may swim either faster or slower in shear-thinning fluids than in Newtonian fluids. We explain this kinematic sensitivity by considering differences in the viscosity of the fluid surrounding propulsive and payload elements of the swimmer, and using this insight suggest two reciprocal sliding sphere swimmers which violate Purcell's Scallop theorem in shear-thinning fluids. We also show that an increased flow decay rate arising from shear-thinning rheology is associated with a reduction in the swimming speed of slip-velocity squirmers. For sperm-like swimmers, a gradient of thick to thin fluid along the flagellum alters the force it exerts upon the fluid, flattening trajectories and increasing instantaneous swimming speed.Comment: 22 pages, 28 figure

Insight into the X‐ray absorption spectra of Cu‐porphyrazines from electronic structure theory

Transition metal porphyrazines are a widely used class of compounds with applications in catalysis, organic solar cells, photodynamic therapy, and nonlinear optics. The most prominent members of that family of compounds are metallophtalocyanines, which have been the subject of numerous spectroscopic and theoretical studies. In this work, the electronic structure and X‐ray absorption characteristics of three Cu‐porphyrazine derivatives are investigated by means of modern electronic structure theory. More precisely, the experimentally observed N K‐edge and Cu L‐edge features are presented and reproduced by time‐dependent density functional theory, restricted open‐shell configuration interaction, and a restricted active space approach. Where possible, the calculations are used to interpret the observed spectroscopic features in terms of electronic transitions and, furthermore, to connect spectral differences to chemical variations. Part of the discussion of the computational results concerns the impact of various parameters and approximations that are used for the calculations, for example, the choice of active space

Gestalt Principles in Ligeti’s Piano Etude “Desordre”

This document is a study of how Gestalt principles of organization are at work in “Désordre” (1985), the first etude in the first book of piano etudes by György Ligeti (1923–2006). After explaining how Gestalt principles can be applied to the analysis of music, the study presents an analysis of the etude in four main parts. The first part identifies elements of the composition that help the listener define boundaries between phrases, phrase groups, and sections. The second part discusses how foreground and background layers are articulated. The third part discusses the polytempo illusion. The fourth and final part identifies elements that contribute to large-scale unity in the composition. Finally, some pedagogical applications for teaching composition are briefly addressed

Non-Gaussian Features of Transmitted Flux of QSO's Lyα\alpha Absorption: Intermittent Exponent

We calculate the structure function and intermittent exponent of the 1.) Keck data, which consists of 29 high resolution, high signal to noise ratio (S/N) QSO Ly$\alpha$ absorption spectra, and 2.)the Ly$\alpha$ forest simulation samples produced via the pseudo hydro scheme for the low density cold dark matter (LCDM) model and warm dark matter (WDM) model with particle mass $m_W=300, 600, 800$ and 1000 eV. These two measures detect not only non-gaussianities, but also the type of non-gaussianty in the the field. We find that, 1.) the structure functions of the simulation samples are significantly larger than that of Keck data on scales less than about 100 h$^{-1}$ kpc, 2.) the intermittent exponent of the simulation samples is more negative than that of Keck data on all redshifts considered, 3.) the order-dependence of the structure functions of simulation samples are closer to the intermittency of hierarchical clustering on all scales, while the Keck data are closer to a lognormal field on small scales. These differences are independent of noise and show that the intermittent evolution modeled by the pseudo-hydro simulation is substantially different from observations, even though they are in good agreement in terms of second and lower order statistics. (Abridged)Comment: 17 pages, 13 figures. Accepted by Ap