Equivariant Dimensional Reduction and Quiver Gauge Theories

We review recent applications of equivariant dimensional reduction techniques to the construction of Yang-Mills-Higgs-Dirac theories with dynamical mass generation and exactly massless chiral fermions.Comment: 10 pages; Based on invited talk given by the first author at the 2nd School on "Quantum Gravity and Quantum Geometry" session of the 9th Hellenic School on Elementary Particle Physics and Gravity, Corfu, Greece, September 13-20 2009. To be published in General Relativity and Gravitatio

Implications of Particle Acceleration in Active Galactic Nuclei for Cosmic Rays and High Energy Neutrino Astronomy

We consider the production of high energy neutrinos and cosmic rays in radio-quiet active galactic nuclei (AGN) or in the central regions of radio-loud AGN. We use a model in which acceleration of protons takes place at a shock in an accretion flow onto a supermassive black hole, and follow the cascade that results from interactions of the accelerated protons in the AGN environment. We use our results to estimate the diffuse high energy neutrino intensity and cosmic ray intensity due to AGN. We discuss our results in the context of high energy neutrino telescopes under construction, and measurements of the cosmic ray composition in the region of the ``knee'' in the energy spectrum at $\sim 10^7$ GeV.Comment: 37 pages of compressed and uuencoded postscript; hardcopy available on request; to be published in Astroparticle Physics; ADP-AT-94-

Analysis of X-ray spectra emitted from laser-produced plasmas of uranium

In this paper, we used the multiconfiguration Dirac-Fock method to generate theoretical X-ray spectra for Co-, Ni-, Cu-, Zn-, Ga-, Ge-, As-, Se-, Br-, Kr-, and Rb-like uranium ions. Using the distribution of these ions in a laser-produced plasma, for different plasma temperatures, we generate theoretical spectra, which are compared to experimental data

Thermal measurement and modeling of multi-die packages

Thermal measurement and modeling of multi-die packages became a hot topic recently in different fields like RAM chip packaging or LEDs / LED assemblies, resulting in vertical (stacked) and lateral arrangement. In our present study we show results for a mixed arrangement: an opto-coupler device has been investigated with 4 chips in lateral as well as vertical arrangement. In this paper we give an overview of measurement and modeling techniques and results for stacked and MCM structures, describe our present measurement results together with our structure function based methodology of validating the detailed model of the package being studied. Also, we show how to derive junction-to-pin thermal resistances with a technique using structure functions.Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

Electronic structure of amorphous germanium disulfide via density functional molecular dynamics simulations

Using density functional molecular dynamics simulations we study the electronic properties of glassy g-GeS$_2$. We compute the electronic density of states, which compares very well with XPS measurements, as well as the partial EDOS and the inverse participation ratio. We show the electronic contour plots corresponding to different structural environments, in order to determine the nature of the covalent bonds between the atoms. We finally study the local atomic charges, and analyze the impact of the local environment on the charge transfers between the atoms. The broken chemical order inherent to amorphous systems leads to locally charged zones when integrating the atomic charges up to nearest-neighbor distances.Comment: 13 pages, 9 figures; to appear in Phys. Rev.

3D-2D crossover in the naturally layered superconductor (LaSe)1.14(NbSe2)

The temperature and angular dependencies of the resistive upper critical magnetic field $B_{c2}$ reveal a dimensional crossover of the superconducting state in the highly anisotropic misfit-layer single crystal of (LaSe)$_{1.14}$(NbSe$_2$) with the critical temperature $T_c$ of 1.23 K. The temperature dependence of the upper critical field $B_{c2\parallel ab}(T)$ for a field orientation along the conducting $(ab)$-planes displays a characteristic upturn at 1.1 K and below this temperature the angular dependence of $B_{c2}$ has a cusp around the parallel field orientation. Both these typical features are observed for the first time in a naturally crystalline layered system.Comment: 7 pages incl. 3 figure

Lithofacies and Mineralogy of the Late Wisconsinan Navarre Till in Stark and Wayne Counties, Ohio

Author Institution: Department of Geology, University of AkronThe Navarre Till deposited by ice of the Killbuck lobe in Stark and Wayne counties is the oldest till of late Wisconsinan age in northeastern Ohio. The type section of the Navarre Till is located near the margin of glaciation in Stark County. Interpretations of the diamict at the type locality include a meltout till overlying shale. Other sections in the study area consist of meltout or flow tills which occur as stratified or massive diamicts interbedded with silts, sands, and gravels. Diamict interpreted as lodgement till occurs only at one section