First experimental demonstration of temporal hypertelescope operation with a laboratory prototype

In this paper, we report the first experimental demonstration of a Temporal HyperTelescope (THT). Our breadboard including 8 telescopes is firstly tested in a manual cophasing configuration on a 1D object. The Point Spread Function (PSF) is measured and exhibits a dynamics in the range of 300. A quantitative analysis of the potential biases demonstrates that this limitation is related to the residual phase fluctuation on each interferometric arm. Secondly, an unbalanced binary star is imaged demonstrating the imaging capability of THT. In addition, 2D PSF is recorded even if the telescope array is not optimized for this purpose.Comment: Accepted for publication in MNRAS. 11 pages, 25 figure

Sleep Disruption and Cancer Incidence in a Southeastern Veteran Population

Sleep disruption influences biological processes that can facilitate carcinogenesis. However, studies examining the relationship between sleep disruption and cancer risk have been inconclusive. This retrospective cohort study used de-identified data from the Veterans Administration (VA) electronic medical record to test the hypothesis that sleep disorder diagnoses among Veterans seeking care in the Southeast United States Service Network are associated with increased risk for cancer of the prostate, breast, colorectum, or total cancer (1999-2010, N=663,869). Sleep disorders were defined as patients with an in- or out-patient diagnosis as specified by the International Classification of Sleep Disorders. Cancer cases were defined as patients identified in the VA Tumor Registry during the follow-up period with a histologically confirmed primary tumor (any stage, excluding benign or in situ tumors). The relationship between a prior sleep disorder diagnosis and cancer incidence was summarized using extended Cox regression analyses with sleep disorder diagnosis as a time-varying co-variate. Sleep disorders were identified among 56,055 (8%) of eligible patients; sleep apnea (46%) and insomnia (40%) were the most common diagnoses among those with sleep disorders. There were 18,138 cancer diagnoses in the study population (42% prostate, 12% colorectal, 1% female breast, 46% other). Hazard ratios (HRs) for any cancer diagnosis ranged from 1.34 to 1.69 among patients with a diagnosed sleep disorder relative to those without sleep disorders, after adjustment for the effects of age, sex, state of residence, and marital status. There was a tendency for increased cancer risks with increasing sleep disorder duration (1-year HR: 1.04, 95% confidence interval [CI]: 1.03-1.06), (5-year HR: 1.23, 95% CI: 1.16-1.32), or (10-year HR: 1.52, 95% CI: 1.34-1.73). Results among patients with only sleep apnea, insomnia, or all other sleep disorder diagnoses were similar to those for all sleep disorders combined. Results from this study suggest that Veterans with a diagnosed sleep disorder have an increased cancer risk, and that risk increases with increasing sleep disorder duration. Optimal sleep and appropriate sleep disorder management represent modifiable risk factors that may facilitate cancer prevention

Robust self-scheduling of a price-maker energy storage facility in the New York electricity market

Recent progress in energy storage raises the possibility of creating large-scale storage facilities at lower costs. This may bring economic opportunities for storage operators, especially via energy arbitrage. However, storage operation in the market could have a noticeable impact on electricity prices. This work aims at evaluating jointly the potential operating profit for a price-maker storage facility and its impact on the electricity prices in the New York state market. Based on historical data, lower and upper bounds on the supply curve of the market are constructed. These bounds are used as an input for the robust self-scheduling problem of a price-maker storage facility. Our computational experiments show that the robust strategies thus obtained allow to reduce significantly the loss exposure while maintaining reasonably high expected profits

Optical fiber systems are convectively unstable

We theoretically and experimentally evidence that fiber systems are convective systems since their nonlocal inherent properties, such as the dispersion and Raman effects, break the reflection symmetry. Theoretical analysis and numerical simulations carried out for a fiber ring cavity demonstrate that the third-order dispersion term leads to the appearance of convective and absolute instabilities. Their signature is an asymmetry in the output power spectrum. Using this criterion, experimental evidence of convective instabilities is given in a fiber cavity pumped by a pulsed laser

Controlling suction by vapour equilibrium technique at different temperatures, application to the determination of the water retention properties of MX80 clay

Problems related to unsaturated soils are frequently encountered in geotechnical or environmental engineering works. In most cases, for the purpose of simplicity, the problems are studied by considering the suction effects on volume change or shear strength under isothermal conditions. Under isothermal condition, very often, a temperature independent water retention curve is considered in the analysis, which is obviously a simplification. When the temperature changes are too significant to be neglected, it is necessary to account for the thermal effects. In this paper, a method for controlling suction using the vapour equilibrium technique at different temperatures is presented. First, calibration of various saturated saline solutions was carried out from temperature of 20 degrees C to 60 degrees C. A mirror psychrometer was used for the measurement of relative humidity generated by saturated saline solutions at different temperatures. The results obtained are in good agreement with the data from the literature. This information was then used to determine the water retention properties of MX80 clay, which showed that the retention curve is shifting down with increasing of temperature

The impact of the Southern Annular Mode on future changes in Southern Hemisphere rainfall

A robust positive trend in the Southern Annular Mode (SAM) is projected for the end of the 21st century under the Representative Concentration Pathway 8.5 scenario, which results in rainfall decreases in the midlatitudes and increases in the high latitudes in the Southern Hemisphere (SH). We find that this SAM trend also increases rainfall over the SH subtropics in austral summer but not in winter, leading to a pronounced wintertime poleward expansion of the subtropical dry zone. These dynamically driven rainfall changes by the SAM appear to oppose the thermodynamically driven projected rainfall changes in the SH subtropics and midlatitudes, whereas the two components reinforce each other in the high latitudes. However, we show that most climate models fall short in capturing the observed SAM component driven by the El Nino-Southern Oscillation and associated rainfall in the austral warm seasons, which limits our confidence in quantifying the contribution of the SAM to projected rainfall changes.11145Ysciescopu

SPHERE: Irradiation of sphere-pac fuel of UPuO2−x containing 3% Americium

AbstractAmericium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors of long-lived nuclides like 241Am is therefore an option for the reduction of radiotoxicity of waste packages to be stored in a repository. The SPHERE irradiation experiment is the latest of a series of European experiments on americium transmutation (e.g. EFTTRA-T4, EFTTRA-T4bis, HELIOS, MARIOS) performed in the HFR (High Flux Reactor). The SPHERE experiment is carried out in the framework of the 4-year project FAIRFUELS of the EURATOM 7th Framework Programme (FP7). During the past years of experimental works in the field of transmutation and tests of innovative nuclear fuels, the release or trapping of helium as well as helium induced fuel swelling have been shown to be the key issues for the design of Am-bearing targets. The main objective of the SPHERE experiment is to study the in-pile behaviour of fuel containing 3% of americium and to compare the behaviour of sphere-pac fuel to pellet fuel, in particular the role of microstructure and temperature on fission gas release (mainly He) and on fuel swelling.The SPHERE experiment is being irradiated since September 2013 in the HFR in Petten (The Netherlands) and is expected to be terminated in spring 2015. The experiment has been designed to last up to 18 reactor cycles (corresponding to 18 months) but may reach its target earlier.This paper discusses the rationale and objective of the SPHERE experiment and provides a general description of its design

Fractal Conductance Fluctuations in a Soft Wall Stadium and a Sinai Billiard

Conductance fluctuations have been studied in a soft wall stadium and a Sinai billiard defined by electrostatic gates on a high mobility semiconductor heterojunction. These reproducible magnetoconductance fluctuations are found to be fractal confirming recent theoretical predictions of quantum signatures in classically mixed (regular and chaotic) systems. The fractal character of the fluctuations provides direct evidence for a hierarchical phase space structure at the boundary between regular and chaotic motion.Comment: 4 pages, 4 figures, data on Sinai geometry added to Fig.1, minor change

Resonance Patterns of an Antidot Cluster: From Classical to Quantum Ballistics

We explain the experimentally observed Aharonov-Bohm (AB) resonance patterns of an antidot cluster by means of quantum and classical simulations and Feynman path integral theory. We demonstrate that the observed behavior of the AB period signals the crossover from a low B regime which can be understood in terms of electrons following classical orbits to an inherently quantum high B regime where this classical picture and semiclassical theories based on it do not apply.Comment: 5 pages revtex + 2 postscript figure