Interactive LORAN-C to geographic and geographic-to-LORAN-C computation

The LORAN program is stored in CMS disk files for use by Avionics Engineering Center terminal users. A CMS EXEC file named LORAN controls program operation. The user types LORAN and the program then prompts for data input and produces output on the terminal. The FORTRAN program refers to a disk file of LORAN master data giving station locations, coding delays, repetition rate and station pair identification letters. For Geographic-to-LORAN conversion, no iterative computations are required; the program is a straightforward coordinate conversion based upon the techniques described by the Navy. For LORAN-to-Geographic conversion, the original Navy program required a dead-reckoned position, near the actual unknown fix, to begin computations. No iteration was performed to obtain the LORAN fix, but internal program errors occurred at execution time if the dead-reckoned fix were displaced from the actual fix by more than a few minutes of latitude or longitude. In order to enhance usefulness of the program for the terminal user, an iterative routine was added which allows a single dead-reckoned position to be entered from the master data file for each LORAN chain. The results compare exactly with the LORAN-C navigation chart, and provide adequate benchmark data for general aviation flight planning and data analysis

On some aspects of the noise propagation from supersonic aircraft

The noise problem associated with an aircraft flying at supersonic speeds is shown to depend primarily on the shock wave pattern formed by the aircraft. The noise intensity received by a ground observer from a supersonic aircraft flying at high as well as low altitudes, is shown to be high although it is of a transient nature. Continues

Recent integral cross section validation measurements at the ASP facility

This work presents new integral data measured at the ASP 14 MeV neutron irradiation facility at Aldermaston in the UK, which has recently become available for fusion-related work through the CCFE materials programme. Measurements of reaction products from activation experiments using elemental foils were carried out using gamma spectrometry in a high efficiency, high-purity germanium (HPGe) detector and associated digital signal processing hardware. Following irradiation and rapid extraction to the measurement cell, gamma emissions were acquired with both energy and time bins. Integral cross section and half-life data have been derived from these measurements. Selected integral cross section values are presented from the measurement campaigns.Comment: 4 pages, 5 figure

Peer effects on the United States Supreme Court

Using data on essentially every U.S. Supreme Court decision since 1946, we estimate a model of peer effects on the Court. We estimate the impact of justice ideology and justice votes on the votes of their peers. To identify the peer effects, we use two instruments that generate plausibly exogenous variation in the peer group itself, or in the votes of peers. The first instrument utilizes the fact that the composition of the Court varies from case to case due to recusals or absences for health reasons. The second utilizes the fact that many justices previously sat on Federal Circuit Courts, and justices are generally much less likely to overturn decisions in cases sourced from their former “home” court. We find large peer effects. For example, we can use our model to predict the impact of replacing Justice Ginsburg with Justice Barrett. Under the the assumption that Justice Barrett's ideological position aligns closely with Justice Scalia, for whom she clerked, we predict that her influence on the Court will increase the Conservative vote propensity of the other justices by 4.7 percentage points. That translates into 0.38 extra conservative votes per case on top of the impact of her own vote. In general, we find indirect effects are large relative to the direct mechanical effect of a justice's own vote

Applying the Macroscopic Chemistry Method to Dissociating Oxygen

The macroscopic chemistry method [Lilley and Macrossan, Phys. Fluids, v16, p2054, 2004] was developed to model non-equilibrium chemically reacting flows with the direct simulation Monte Carlo (DSMC) method. The macroscopic method uses kinetic temperatures, calculated from mean particle energies, to calculate reaction rates. For strongly non-equilibrium flows, it is possible the macroscopic method might ignore reactions that should result from high-energy collisions that occur in the high-energy tail of the collision energy distribution. This could result in a "rate-reducing" effect relative to conventional collision-based DSMC chemistry models that perform reactions based on the energy of each individual collision. This effect would be most pronounced for reactions with low activation energy. We test for this possible rate-reducing effect in the macroscopic method by calculating the hypersonic flow of dissociating oxygen, which has a low dissociation energy, over a blunt cylinder. The results are compared to those obtained with the most common collision-based DSMC chemistry method, the total collision energy model. The results are in close agreement and we find no rate-reducing effect with the macroscopic method. This result extends the scope of the macroscopic method, and demonstrates its potential for modelling reacting non-equilibrium gas flows with the DSMC method

A new decoupled rotational energy exchange scheme for DSMC calculations

We present a new scheme for modeling rotational energy exchange with the direct simulation Monte Carlo (DSMC) method. The new scheme is fundamentally different from conventional Borgnakke-Larsen (BL) procedures, in which energy exchange is performed at the time of collision. In the new scheme, all collisions are performed elastically. Rotational energy exchanged is performed after the collision routine, in an independent step. The rotational energy of all particles in each cell is adjusted by a factor, to satisfy the desired macroscopic relaxation behavior. To conserve total energy in a cell, the thermal velocities of all particles in the cell are adjusted. DSMC calculations of shock structure show that the new scheme gives results in reasonable agreement with those provided by conventional BL procedures. The new scheme has a potential advantage over BL procedures - it is easy to use with any DSMC collision model

Three-dimensional calculation of shuttle charging in polar orbit

The charged particles environment in polar orbit can be of sufficient intensity to cause spacecraft charging. In order to gain a quantitative understanding of such effects, the Air Force is developing POLAR, a computer code which simulates in three dimensions the electrical interaction of large space vehicles with the polar ionospheric plasma. It models the physical processes of wake generation, ambient ion collection, precipitating auroral electron fluxes, and surface interactions, including secondary electron generation and backscattering, which lead to vehicle charging. These processes may be followed dynamically on a subsecond timescale so that the rapid passage through intense auroral arcs can be simulated. POLAR models the ambient plasma as isotropic Maxwellian electrons and ions (0+, H+), and allows for simultaneous precipitation of power-law, energetic Maxwellian, and accelerated Gaussian distributions of electrons. Magnetic field effects will be modeled in POLAR but are currently ignored

The sign convention for quadrature Parkinson arrows in geomagnetic induction studies

Time series analysis, which is basic to modern geophysical data processing, involves a choice between working with a time dependence of e+iωt or e-iωt. In published work the choice made is sometimes not explicitly stated, leaving ambiguity in the interpretation of complex quantities with quadrature parts. Parkinson arrows are used in geomagnetic induction studies to summarize anomalous vertical magnetic fluctuations at different observing stations and to indicate regions of high electrical conductivity. Such arrows are now regularly computed as real and quadrature pairs. The general convention is often adopted of 'reversing' a calculated real arrow so that it will point toward a conductivity increase, but for quadrature arrows the practice between various published papers has generally not been so consistent. The present paper demonstrates that consistent practice for reversing or not reversing quadrature Parkinson arrows is possible when the initial convention for time dependence is taken into account. A reversal practice is determined for interpretation in terms of a simple channeling model. A related matter is the definition of phase. Phase values are also generally ambiguous unless the time dependence used (e-iωt or e+iωt) is stated

4-Phosphothiophen-2-yl alanine: a new 5-membered analogue of phosphotyrosine

Polyclonal antibodies raised against 4-phosphothiophen-2-yl alanine 2a, a novel five-membered ring analogue of phosphotyrosine, showed high selectivity for phosphotyrosine and no cross-reactivity with other phosphorylated amino acids. Western blots showed that the polyclonal was similarly effective, but different in selectivity, to a commercially available monoclonal antibody