Direct Measurement of Neutron-Star Recoil in the Oxygen-Rich Supernova Remnant Puppis A

A sequence of three Chandra X-ray Observatory High Resolution Camera images taken over a span of five years reveals arc-second-scale displacement of RX J0822-4300, the stellar remnant (presumably a neutron star) near the center of the Puppis A supernova remnant. We measure its proper motion to be 0.165+/-0.025 arcsec/yr toward the west-southwest. At a distance of 2 kpc, this corresponds to a transverse space velocity of ~1600 km/s. The space velocity is consistent with the explosion center inferred from proper motions of the oxygen-rich optical filaments, and confirms the idea that Puppis A resulted from an asymmetric explosion accompanied by a kick that imparted roughly 3*10^49 ergs of kinetic energy (some 3 percent of the kinetic energy for a typical supernova) to the stellar remnant. We discuss constraints on core-collapse supernova models that have been proposed to explain neutron star kick velocities

Compact strain-sensitive flexible photonic crystals for sensors

A promising fabrication route to produce absorbing flexible photonic crystals is presented, which exploits self-assembly during the shear processing of multi-shelled polymer spheres. When absorbing material is incorporated in the interstitial space surrounding high-refractive-index spheres, a dramatic enhancement in the transmission edge on the short-wavelength side of the band gap is observed. This effect originates from the shifting optical field spatial distribution as the incident wavelength is tuned around the band gap, and results in a contrast up to 100 times better than similar but nonabsorbing photonic crystals. An order-of-magnitude improvement in strain sensitivity is shown, suggesting the use of these thin films in photonic sensors

Development of the mathematical model of catalytic cracking: identification of hydrocarbon of the vacuum distillate usin chromatomass- spectrometry

Information about composition of catalytic cracking raw materials and products is required fordevelopment of mathematical model of catalytic cracking. The results of laboratory investigation ondetermination of the composition of catalytic cracking vacuum distillate were performed in this work. Groupcomposition of the catalytic cracking raw materials was defined using liquid-adsorption chromatographicseparation on silica gel. Paraffin-naphthenic and aromatic fraction was indefined by chromato-massspectrometry

Changes to Rural Migration in the COVID-19 Pandemic☆

Media stories highlighted accounts of migration away from city centers towards more rural destinations during the COVID-19 pandemic, but systematic research about how the pandemic changed migration in more rural destinations is only starting to emerge. This paper relies on U.S. Postal Service change-of-address data to describe whether and how established domestic migration systems changed during the COVID-19 pandemic, focusing on differences across the rural–urban gradient and by outdoor recreation resources. We find little evidence of massive urban exodus. We do find that out-migration from rural counties declined post-pandemic onset and has stayed low in the 3 years since, stemming the tide of net population loss in many rural places. Most rural counties that experienced net population loss prior to the pandemic saw either less net loss or net gains during the pandemic. Rural recreation counties experienced greater gains through both decreased out-migration and increased in-migration in the first year of the pandemic; but by year three, differences between rural recreation and non-recreation counties had balanced. Overall, counties across Rural America saw notable change to pre-pandemic migration patterns. This shift may benefit rural areas through long-term population stability and/or growth but might also exacerbate housing and childcare shortages

Demonstration of detuned dual recycling at the Garching 30m laser interferometer

Dual recycling is an advanced optical technique to enhance the signal-to-noise ratio of laser interferometric gravitational wave detectors in a limited bandwidth. To optimise the center of this band with respect to Fourier frequencies of expected gravitational wave signals detuned dual recycling has to be implemented. We demonstrated detuned dual recycling on a fully suspended 30m prototype interferometer. A control scheme that allows to tune the detector to different frequencies will be outlined. Good agreement between the experimental results and numerical simulations has been achieved.Comment: 9 page

Robotic-assisted Sacrocolpopexy with versus without Concomitant Midurethral Sling: A 2-year Follow-up of Urinary Symptoms and Quality of Life

© 2018 Journal of Mid-life Health | Published by Wolters Kluwer - Medknow. Objective: The objective of this study was to assess long-term postoperative urinary incontinence (UI) symptoms and quality of life (QOL) in patients after robotic-assisted sacrocolpopexy (RASC) with or without concomitant midurethral sling (MUS). Materials and Methods: This is a cross-sectional survey of patients comparing long-term postoperative urinary symptoms and QOL measurements in women who underwent RASC with or without MUS. We included all patients from 2011 to 2014 who had RASC with or without MUS. All patients had preoperative urodynamic testing (UDS). Patients who demonstrated stress UI on UDS underwent MUS at the time of RASC. Urinary symptoms and QOL were assessed through the validated Urinary Distress Inventory-6 (UDI-6) and Incontinence Impact Questionnaire-7 (IIQ-7) patient questionnaires. Results: Sixty-eight patients met inclusion criteria, 46 patients completed follow-up questionnaires, and were included in the final analysis. Average length of time to follow-up from surgery was 24 months (range: 6-36 months). A statistically significant difference in UDI-6 scores between the two groups (RASC vs. RASC + MUS) was observed. Median (25thand 75thpercentiles) scores for UDI-6 were 22.92 (8.33 and 32.29, respectively) for the RASC group and 4.17 (0 and 13.54, respectively) for the RASC + MUS group (P = 0.0017). Median scores for IIQ-7 were 0 (0 and 29.73 for the 25thand 75thpercentiles, respectively) for the RASC group and 0 (0 and 0, respectively) for the RASC + MUS group (P = 0.1691). Conclusion: Patients who underwent RASC + MUS scored significantly lower on the UDI-6, indicating fewer urinary distress symptoms. Although not statistically significant, patients in the RASC + MUS group had lower IIQ-7 scores, indicating less negative impact on QOL, compared to the RASC-only group

Standing wave oscillations in binary mixture convection: from onset via symmetry breaking to period doubling into chaos

Oscillatory solution branches of the hydrodynamic field equations describing convection in the form of a standing wave (SW) in binary fluid mixtures heated from below are determined completely for several negative Soret coefficients. Galerkin as well as finite-difference simulations were used. They were augmented by simple control methods to obtain also unstable SW states. For sufficiently negative Soret coefficients unstable SWs bifurcate subcritically out of the quiescent conductive state. They become stable via a saddle-node bifurcation when lateral phase pinning is exerted. Eventually their invariance under time-shift by half a period combined with reflexion at midheight of the fluid layer gets broken. Thereafter they terminate by undergoing a period-doubling cascade into chaos

Skyrmion automotion in confined counter-sensor device geometries

Magnetic skyrmions are topologically stabilized quasi-particles and are promising candidates for energy-efficient applications, such as storage but also logic and sensing. Here we present a new concept for a multi-turn sensor-counter device based on skyrmions, where the number of sensed rotations is encoded in the number of nucleated skyrmions. The skyrmion-boundary force in the confined geometry of the device in combination with the topology-dependent dynamics leads to the effect of automotion for certain geometries. For our case, we describe and investigate this effect with micromagnetic simulations and the coarse-grained Thiele equation in a triangular geometry with an attached reservoir as part of the sensor-counter device