X-ray production in low energy proton stopping

The X-ray yields of stopping protons in an iron-nickel-cobalt alloy are calculated for use in predicting radiation damage in encased electronic devices

Orthogonality catastrophe as a consequence of qubit embedding in an ultra-cold Fermi gas

We investigate the behaviour of a single qubit coupled to a low-dimensional, ultra-cold Fermi gas. The scattering between the system and the fermions leads to the loss of any coherence in the initial state of the qubit and we show that the exact dynamics of this process is strongly influenced by the effect of the orthogonality catastrophe within the gas. We highlight the relationship between the Loschmidt echo and the retarded Green's function - typically used to formulate the dynamical theory of the catastrophe - and demonstrate that the effect can be triggered and characterized via local operations on the qubit. We demonstrate how the expected broadening of the spectral function can be observed using Ramsey interferometry on the qubit.Comment: 4 and a bit pages, 3 figures. Updated versio

Effects of cosmic rays on single event upsets

Assistance was provided to the Brookhaven Single Event Upset (SEU) Test Facility. Computer codes were developed for fragmentation and secondary radiation affecting Very Large Scale Integration (VLSI) in space. A computer controlled CV (HP4192) test was developed for Terman analysis. Also developed were high speed parametric tests which are independent of operator judgment and a charge pumping technique for measurement of D(sub it) (E). The X-ray secondary effects, and parametric degradation as a function of dose rate were simulated. The SPICE simulation of static RAMs with various resistor filters was tested

Graded-index optical fiber emulator of an interacting three-atom system: illumination control of particle statistics and classical non-separability

We show that a system of three trapped ultracold and strongly interacting atoms in one-dimension can be emulated using an optical fiber with a graded-index profile and thin metallic slabs. While the wave-nature of single quantum particles leads to direct and well known analogies with classical optics, for interacting many-particle systems with unrestricted statistics such analoga are not straightforward. Here we study the symmetries present in the fiber eigenstates by using discrete group theory and show that, by spatially modulating the incident field, one can select the atomic statistics, i.e., emulate a system of three bosons, fermions or two bosons or fermions plus an additional distinguishable particle. We also show that the optical system is able to produce classical non-separability resembling that found in the analogous atomic system.Comment: 14 pages, 5 figure

Fast and Slow Rotators in the Densest Environments: a SWIFT IFS study of the Coma Cluster

We present integral-field spectroscopy of 27 galaxies in the Coma cluster observed with the Oxford SWIFT spectrograph, exploring the kinematic morphology-density relationship in a cluster environment richer and denser than any in the ATLAS3D survey. Our new data enables comparison of the kinematic morphology relation in three very different clusters (Virgo, Coma and Abell 1689) as well as to the field/group environment. The Coma sample was selected to match the parent luminosity and ellipticity distributions of the early-type population within a radius 15' (0.43 Mpc) of the cluster centre, and is limited to r' = 16 mag (equivalent to M_K = -21.5 mag), sampling one third of that population. From analysis of the lambda-ellipticity diagram, we find 15+-6% of early-type galaxies are slow rotators; this is identical to the fraction found in the field and the average fraction in the Virgo cluster, based on the ATLAS3D data. It is also identical to the average fraction found recently in Abell 1689 by D'Eugenio et al.. Thus it appears that the average slow rotator fraction of early type galaxies remains remarkably constant across many different environments, spanning five orders of magnitude in galaxy number density. However, within each cluster the slow rotators are generally found in regions of higher projected density, possibly as a result of mass segregation by dynamical friction. These results provide firm constraints on the mechanisms that produce early-type galaxies: they must maintain a fixed ratio between the number of fast rotators and slow rotators while also allowing the total early-type fraction to increase in clusters relative to the field. A complete survey of Coma, sampling hundreds rather than tens of galaxies, could probe a more representative volume of Coma and provide significantly stronger constraints, particularly on how the slow rotator fraction varies at larger radii.Comment: Accepted for publication in MNRA

Does the presence of connective tissue disease modify survival in patients with pulmonary fibrosis?

SummaryObjectivesPrevious studies into the survival differences between individuals with idiopathic pulmonary fibrosis and those with connective tissue disease associated pulmonary fibrosis (CTD-PF) have yielded mixed results. The aim of this study is to compare the survival of individuals with CTD-PF to those with idiopathic pulmonary fibrosis clinical syndrome (IPF-CS) using data derived from The Health Improvement network, a large primary care database in the UK.MethodsIncident cases of CTD-PF and IPF-CS between the years 2000–2009 were identified. Survival analysis was performed using Kaplan–Meier methods, stratified by type of connective tissue disease. Cox regression was then used to compare mortality rates between the groups, adjusting for age, gender and year of diagnosis.ResultsA total of 324 cases of CTD-PF and 2209 cases of IPF-CS were followed up over a mean period of 2.3 years. During this period, 113 (34.9%) cases of CTD-PF and 1073 (48.6%) cases of IPF-CS died. The mortality rates for cases with CTD-PF and IPF-CS were 123.6 per 1000 person years (95%CI: 102.8–148.9) and 229.8 per 1000 person years (95% CI: 216.4–244.0) respectively. After adjusting for age, sex and year of diagnosis, cases with CTD-PF had a better prognosis compared to those with IPF-CS (HR 0.76,95%CI: 0.62–0.92).ConclusionThe prognosis of individuals with CTD-PF appears to be significantly better than those with IPF-CS, but remains an important cause of death in patients with connective tissue disease, and requires more effective treatment options

Modeling and experimental verification of single event upsets

The research performed and the results obtained at the Laboratory for Radiation Studies, Prairie View A&M University and Texas A&I University, on the problem of Single Events Upsets, the various schemes employed to limit them and the effects they have on the reliability and fault tolerance at the systems level, such as robotic systems are reviewed

The SAMI Galaxy Survey: Unveiling the nature of kinematically offset active galactic nuclei

We have observed two kinematically offset active galactic nuclei (AGN), whose ionised gas is at a different line-of-sight velocity to their host galaxies, with the SAMI integral field spectrograph (IFS). One of the galaxies shows gas kinematics very different to the stellar kinematics, indicating a recent merger or accretion event. We demonstrate that the star formation associated with this event was triggered within the last 100 Myr. The other galaxy shows simple disc rotation in both gas and stellar kinematics, aligned with each other, but in the central region has signatures of an outflow driven by the AGN. Other than the outflow, neither galaxy shows any discontinuity in the ionised gas kinematics at the galaxy's centre. We conclude that in these two cases there is no direct evidence of the AGN being in a supermassive black hole binary system. Our study demonstrates that selecting kinematically offset AGN from single-fibre spectroscopy provides, by definition, samples of kinematically peculiar objects, but IFS or other data are required to determine their true nature.Comment: MNRAS accepted. 14 pages, 11 figure