Zero-loss/deflection map analysis

Experimental plots of the fraction of detected electrons removed from the zero-loss peak, versus the fraction of incident electrons scattered outside of the objective aperture, can serve as a robust fingerprint of object-contrast in an energy filtered transmission electron microscope (EFTEM). Examples of this, along with the first in a series of models for interpreting the resulting patterns, were presented at the August 2010 meeting of the Microscope Society of America meeting in Portland, Oregon, and published in {\em Microscopy and MicroAnalysis} {\bf 16}, Supplement 2, pages 1534-1535 by Cambridge University Press.Comment: 3 pages (3 figs, 4 refs) RevTeX, cf. http://www.umsl.edu/~fraundorfp/zldeflmaps.htm

Mood, motility and 17-hydroxycorticoid excretion - a polyvariable case study

Mood, motility, and 17-hydroxycorticoid excretion in cyclic manic-depressive patien

Optimisation of confinement in a fusion reactor using a nonlinear turbulence model

The confinement of heat in the core of a magnetic fusion reactor is optimised using a multidimensional optimisation algorithm. For the first time in such a study, the loss of heat due to turbulence is modelled at every stage using first-principles nonlinear simulations which accurately capture the turbulent cascade and large-scale zonal flows. The simulations utilise a novel approach, with gyrofluid treatment of the small-scale drift waves and gyrokinetic treatment of the large-scale zonal flows. A simple near-circular equilibrium with standard parameters is chosen as the initial condition. The figure of merit, fusion power per unit volume, is calculated, and then two control parameters, the elongation and triangularity of the outer flux surface, are varied, with the algorithm seeking to optimise the chosen figure of merit. A two-fold increase in the plasma power per unit volume is achieved by moving to higher elongation and strongly negative triangularity.Comment: 32 pages, 8 figures, accepted to JP

Additional extensions to the NASCAP computer code, volume 1

Extensions and revisions to a computer code that comprehensively analyzes problems of spacecraft charging (NASCAP) are documented. Using a fully three dimensional approach, it can accurately predict spacecraft potentials under a variety of conditions. Among the extensions are a multiple electron/ion gun test tank capability, and the ability to model anisotropic and time dependent space environments. Also documented are a greatly extended MATCHG program and the preliminary version of NASCAP/LEO. The interactive MATCHG code was developed into an extremely powerful tool for the study of material-environment interactions. The NASCAP/LEO, a three dimensional code to study current collection under conditions of high voltages and short Debye lengths, was distributed for preliminary testing

Additional extensions to the NASCAP computer code, volume 2

Particular attention is given to comparison of the actural response of the SCATHA (Spacecraft Charging AT High Altitudes) P78-2 satellite with theoretical (NASCAP) predictions. Extensive comparisons for a variety of environmental conditions confirm the validity of the NASCAP model. A summary of the capabilities and range of validity of NASCAP is presented, with extensive reference to previously published applications. It is shown that NASCAP is capable of providing quantitatively accurate results when the object and environment are adequately represented and fall within the range of conditions for which NASCAP was intended. Three dimensional electric field affects play an important role in determining the potential of dielectric surfaces and electrically isolated conducting surfaces, particularly in the presence of artificially imposed high voltages. A theory for such phenomena is presented and applied to the active control experiments carried out in SCATHA, as well as other space and laboratory experiments. Finally, some preliminary work toward modeling large spacecraft in polar Earth orbit is presented. An initial physical model is presented including charge emission. A simple code based upon the model is described along with code test results

Some Properties Of Memoryless Multiterminal Interference Channels

This paper examines some properties of memoryless multiterminal interference channels. A general formula for the capacity of such channels is presented. However this formula does not easily lend itself to computation. Motivated by the fact that for a single user memoryless channel (l/N)Sup[ I(X;Y) ] is independent of N (where X and Y are N-vectors and the suprema is taken over all probability distributions on X), we are investigating the possibility that the general capacity formula has an analogous simplification. A specific example of a Gaussian interference channel with two independent users is considered. It is shown that certain probability distributions for N=2 achieve points on the boundary of the capacity region. We hope that some form of this result will generalize to other multiterminal communication channels, and possibly give some insight into the nature of the channel capacity in terms of a single-letter description. Presently, the capacity region of such channels is, in general, unknown

Marginalising instrument systematics in HST WFC3 transit lightcurves

Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) infrared observations at 1.1-1.7$\mu$m probe primarily the H$_2$O absorption band at 1.4$\mu$m, and has provided low resolution transmission spectra for a wide range of exoplanets. We present the application of marginalisation based on Gibson (2014) to analyse exoplanet transit lightcurves obtained from HST WFC3, to better determine important transit parameters such as R$_p$/R$_*$, important for accurate detections of H$_2$O. We approximate the evidence, often referred to as the marginal likelihood, for a grid of systematic models using the Akaike Information Criterion (AIC). We then calculate the evidence-based weight assigned to each systematic model and use the information from all tested models to calculate the final marginalised transit parameters for both the band-integrated, and spectroscopic lightcurves to construct the transmission spectrum. We find that a majority of the highest weight models contain a correction for a linear trend in time, as well as corrections related to HST orbital phase. We additionally test the dependence on the shift in spectral wavelength position over the course of the observations and find that spectroscopic wavelength shifts $\delta_\lambda(\lambda)$, best describe the associated systematic in the spectroscopic lightcurves for most targets, while fast scan rate observations of bright targets require an additional level of processing to produce a robust transmission spectrum. The use of marginalisation allows for transparent interpretation and understanding of the instrument and the impact of each systematic evaluated statistically for each dataset, expanding the ability to make true and comprehensive comparisons between exoplanet atmospheres.Comment: 19 pages, 13 figures, 8 tables, Accepted to Ap