A finite difference solution for the cylindrical expansion of a gas cloud into vacuum

Finite difference method for solution of cylindrical expansion of gas cloud into vacuu

Coexistence of Antiferromagnetism and Superconductivity in Electron-doped High-Tc Superconductors

We present magnetotransport evidence for antiferromagnetism in films of the electron-doped cuprates Pr$_{2-x}$Ce$_x$CuO$_4$. Our results show clear signature of static antiferromagnetism up to optimal doping x=0.15, with a quantum phase transition close to x=0.16, and a coexistence of static antiferromagnetism and superconductivity for 0.12$\le$x$\le$0.15

Lutheranism, Anti-Judaism, And Bach\u27s St. John Passion: With An Annotated Literal Translation Of The Libretto

Bach\u27s St. John Passion is surely one of the monuments of Western music, yet performances have become inevitably controversial. In large part, this is the result of the combination of powerful, highly emotional music coupled with a text that includes passages from a gospel marked by vehement anti-Judaic sentiments. What did this masterpiece mean in Bach\u27s day, and what does it mean today? Although the bibliographies on Bach and on Judaism have grown enormously since World War II, there has been very little work on the relationships between these two areas. This is hardly surprising writers focusing on issues of anti-Semitism often lack musical training and are, in any event, interested in more pressing social and political issues. Bach scholars, on the other hand, have mostly concentrated on narrowly defined musical topics. And strangely, almost no scholarly attention has been given to the relationships between Lutheranism and Judaism as they affect the St. John Passion. Through a reappraisal of Bach\u27s work and its contexts, Michael Marissen confronts Bach and Judaism directly, providing interpretive commentary that could serve as a basis for more informed and sensitive discussions of this troubling work. Consisting of a long interpretive essay, followed by an annotated literal translation of the libretto, a guide to recorded examples, and a detailed bibliography, this concise text provides the reader with the tools to assess the work on its own terms and in the appropriate contexts. The discussion centers first on the principal messages of the St. John Passion: Jesus\u27 identity, his work, and how this affects the lives of his followers. Marissen goes on to suggest that fostering hostility toward Jews is not the subject or purpose of Bach\u27s setting. For those who would reduce Bach\u27s powerful work to its artistry, and for those listeners who find Bach\u27s music deeply meaningful but may not have considered its attendant religious and cultural issues, as well as for those who assume the work essentially teaches con

Is 0716+714 a superluminal blazar?

We present an analysis of new and old high frequency VLBI data collected during the last 10 years at 5--22 GHz. For the jet components in the mas-VLBI jet, two component identifications are possible. One of them with quasi-stationary components oscillating about their mean positions. Another identification scheme, which formally gives the better expansion fit, yields motion with $\sim 9$ $c$ for $H_0=65$ km s$^{-1}$ Mpc$^{-1}$ and $q_0=0.5$. This model would be in better agreement with the observed rapid IDV and the expected high Lorentz-factor, deduced from IDV.Comment: 2 pages, 3 figures, appears in: Proceedings of the 6th European VLBI Network Symposium held on June 25th-28th in Bonn, Germany. Edited by: E. Ros, R.W. Porcas, A.P. Lobanov, and J.A. Zensu

Blade loss transient dynamics analysis, volume 2. Task 2: Theoretical and analytical development. Task 3: Experimental verification

The component element method was used to develop a transient dynamic analysis computer program which is essentially based on modal synthesis combined with a central, finite difference, numerical integration scheme. The methodology leads to a modular or building-block technique that is amenable to computer programming. To verify the analytical method, turbine engine transient response analysis (TETRA), was applied to two blade-out test vehicles that had been previously instrumented and tested. Comparison of the time dependent test data with those predicted by TETRA led to recommendations for refinement or extension of the analytical method to improve its accuracy and overcome its shortcomings. The development of working equations, their discretization, numerical solution scheme, the modular concept of engine modelling, the program logical structure and some illustrated results are discussed. The blade-loss test vehicles (rig full engine), the type of measured data, and the engine structural model are described

Ground State and Resonances in the Standard Model of Non-relativistic QED

We prove existence of a ground state and resonances in the standard model of the non-relativistic quantum electro-dynamics (QED). To this end we introduce a new canonical transformation of QED Hamiltonians and use the spectral renormalization group technique with a new choice of Banach spaces.Comment: 50 pages change

Second order perturbation theory for embedded eigenvalues

We study second order perturbation theory for embedded eigenvalues of an abstract class of self-adjoint operators. Using an extension of the Mourre theory, under assumptions on the regularity of bound states with respect to a conjugate operator, we prove upper semicontinuity of the point spectrum and establish the Fermi Golden Rule criterion. Our results apply to massless Pauli-Fierz Hamiltonians for arbitrary coupling.Comment: 30 pages, 2 figure

Equilibration, generalized equipartition, and diffusion in dynamical Lorentz gases

We prove approach to thermal equilibrium for the fully Hamiltonian dynamics of a dynamical Lorentz gas, by which we mean an ensemble of particles moving through a $d$-dimensional array of fixed soft scatterers that each possess an internal harmonic or anharmonic degree of freedom to which moving particles locally couple. We establish that the momentum distribution of the moving particles approaches a Maxwell-Boltzmann distribution at a certain temperature $T$, provided that they are initially fast and the scatterers are in a sufficiently energetic but otherwise arbitrary stationary state of their free dynamics--they need not be in a state of thermal equilibrium. The temperature $T$ to which the particles equilibrate obeys a generalized equipartition relation, in which the associated thermal energy $k_{\mathrm B}T$ is equal to an appropriately defined average of the scatterers' kinetic energy. In the equilibrated state, particle motion is diffusive