Calculation of compressible flow about three-dimensional inlets with auxiliary inlets, slats and vanes by means of a panel method

An efficient and user oriented method was constructed for calculating flow in and about complex inlet configurations. Efficiency is attained by: (1) the use of a panel method; (2) a technique of superposition for obtaining solutions at any inlet operating condition; and (3) employment of an advanced matrix iteration technique for solving large full systems of equations, including the nonlinear equations for the Kutta condition. User concerns are addressed by the provision of several novel graphical output options that yield a more complete comprehension of the flowfield than was possible previously

Renormalization of the isovector πN\pi N amplitude in pionic atoms

The extraction of the isovector s-wave pi N amplitude from pionic atoms is studied with special emphasis on uncertainties and their dependence on the assumptions made regarding the neutron density distributions in nuclei and on the size of the data base used . Only `global' analyses of pionic-atom data reveal a discrepancy between the extracted isovector s-wave pi N amplitude b_1=-0.108\pm0.007 m_\pi^{-1} and its free pi N counterpart b_1^{free}=-0.0885^{+0.0010}_{-0.0021} m_\pi ^{-1}, where the uncertainty in the neutron densities is included in the error analysis. The role of `deeply bound' pionic atom states is discussed and the reason for failure of these states to provide new information is explained.Comment: 17 pages, 4 figures, slightly extended, accepted by NP

Antiproton-nucleus potentials from global fits to antiprotonic X-rays and radiochemical data

We report on global fits of optical-model parameters to 90 data points for $\bar p$ X-rays and 17 data points of radiochemical data put together. With the help of separate fits to the two kinds of data it is possible to determine phenomenologically the radial region where the absorption of antiprotons takes place and to obtain neutron densities which represent the average behaviour over the periodic table. A finite-range attractive and absorptive $\bar p$-nuclear isoscalar potential fits the data well. Self-consistent dynamical calculations within the RMF model demonstrate that the polarization of the nucleus by the {\it atomic} antiproton is negligible.Comment: 18 pages, 6 figures, one table. Extended discussion, to appear in Nucl. Phys.

Characterising a solid state qubit via environmental noise

We propose a method for characterising the energy level structure of a solid-state qubit by monitoring the noise level in its environment. We consider a model persistent-current qubit in a lossy resevoir and demonstrate that the noise in a classical bias field is a sensitive function of the applied field.Comment: 3 Figure

Sovereign Limits and Regional Opportunities for Global Civil Society in Latin America

In this article, we evaluate whether Latin American participation in international arenas reinforces traditional divides between state and society in global politics or transforms state-society relations in ways compatible with the concept of global civil society. We examine the participation and interaction of Latin American nongovernmental organizations and states at three recent United Nations conferences: the 1992 UN Conference on Environment and Development, the 1993 World Conference on Human Rights, and the 1995 Fourth World Conference on Women. We conclude that Latin Americans are full participants in any emerging global civil society. Their experiences at the 1990s issue conferences closely track those of NGOs of the Northern Hemisphere, notwithstanding the much more recent appearance of NGOs in Latin America. At the same time, Latin Americans bring a regional sensibility to their participation in global processes that reflects recent political developments and debates in the region

Money velocity in an endogenous growth business cycle with credit shocks

The paper sets the neoclassical monetary business cycle model within endogenous growth, adds exchange credit shocks, and finds that money and credit shocks explain much of the velocity variations. The role of the shocks varies across subperiods in an intuitive fashion. Endogenous growth is key to the construction of the money and credit shocks because these have similar effects on velocity, but opposite effects upon growth. The model matches the data's average velocity and simulates well velocity volatility. Its Cagan-like money demand means that money and credit shocks cause greater velocity variation, the higher is the nominal interest rate

A Brownian particle in a microscopic periodic potential

We study a model for a massive test particle in a microscopic periodic potential and interacting with a reservoir of light particles. In the regime considered, the fluctuations in the test particle's momentum resulting from collisions typically outweigh the shifts in momentum generated by the periodic force, and so the force is effectively a perturbative contribution. The mathematical starting point is an idealized reduced dynamics for the test particle given by a linear Boltzmann equation. In the limit that the mass ratio of a single reservoir particle to the test particle tends to zero, we show that there is convergence to the Ornstein-Uhlenbeck process under the standard normalizations for the test particle variables. Our analysis is primarily directed towards bounding the perturbative effect of the periodic potential on the particle's momentum.Comment: 60 pages. We reorganized the article and made a few simplifications of the conten

Variational Calculation for the Equation of State of Nuclear Matter at Finite Temperatures

An equation of state (EOS) for uniform nuclear matter is constructed at zero and finite temperatures with the variational method starting from the realistic nuclear Hamiltonian composed of the Argonne V18 and UIX potentials. The energy is evaluated in the two-body cluster approximation with the three-body-force contribution treated phenomenologically so as to reproduce the empirical saturation conditions. The obtained energies for symmetric nuclear matter and neutron matter at zero temperature are in fair agreement with those by Akmal, Pandharipande and Ravenhall, and the maximum mass of the neutron star is 2.2 Msolar. At finite temperatures, a variational method by Schmidt and Pandharipande is employed to evaluate the free energy, which is used to derive various thermodynamic quantities of nuclear matter necessary for supernova simulations. The result of this variational method at finite temperatures is found to be self-consistent.Comment: Revised Versio