808 research outputs found
Physical and Psychological Aggression in At-Risk Young Couples: Stability and Change in Young Adulthood
Physical and psychological aggression was examined over a 2 1/2-year period for at-risk young couples. It was predicted, first, that there would be persistence in any physical aggression across time in the group of couples who stayed together; second, that stability in levels of aggression toward a partner would be higher for men who remained with the same partner compared to men who repartnered; third, that increases in levels of aggression would occur over time for couples with the same partners; and fourth, that changes in aggression over time would be concordant for couples. Measures of aggression included reports of aggression and observed aggression. Findings indicated considerable stability in aggression for the same-, but not for the different-, partner group
Simulating the density reduction and equity-impact of potential tobacco retail control policies.
Background: Reducing the provision of tobacco is important for decreasing inequalities in smoking and smoking-related harm. Various policies have been proposed to achieve this, but their impacts—particularly on equity—are often unknown. Here, using national-level data, we simulate the impacts of potential policies designed to reduce tobacco outlet density (TOD).
Methods: Tobacco retailer locations (n=9030) were geocoded from Scotland’s national register, forming a baseline. Twelve policies were developed in three types: (1) regulating type of retailer selling tobacco, (2) regulating location of tobacco sales, and (3) area-based TOD caps. Density reduction was measured as mean percentage reduction in TOD across data zones and number of retailers nationally. Equity impact was measured using regression-based Relative Index of Inequality (RII) across income deprivation quintiles.
Results: Policies restricting tobacco sales to a single outlet type (‘Supermarket’; ‘Liquor store’; ‘Pharmacy’) caused >80% TOD reduction and >90% reduction in the number of tobacco outlets nationally. However, RIIs indicated that two of these policies (‘Liquor store’, ‘Pharmacy’) increased socioeconomic inequalities in TOD. Equity-promoting policies included ‘Minimum spacing’ and exclusion zones around ‘Child spaces’. The only policy to remove statistically significant TOD inequalities was the one deliberately targeted to do so (‘Reduce clusters’).
Conclusions: Using spatial simulations, we show that all selected policies reduced provision of tobacco retailing to varying degrees. However, the most ‘successful’ at doing so also increased inequalities. Consequently, policy-makers should consider how the methods by which tobacco retail density is reduced, and success measured, align with policy aims
Development of large radii half-wave plates for CMB satellite missions
The successful European Space Agency (ESA) Planck mission has mapped the
Cosmic Microwave Background (CMB) temperature anisotropy with unprecedented
accuracy. However, Planck was not designed to detect the polarised components
of the CMB with comparable precision. The BICEP2 collaboration has recently
reported the first detection of the B-mode polarisation. ESA is funding the
development of critical enabling technologies associated with B-mode
polarisation detection, one of these being large diameter half-wave plates. We
compare different polarisation modulators and discuss their respective
trade-offs in terms of manufacturing, RF performance and thermo-mechanical
properties. We then select the most appropriate solution for future satellite
missions, optimized for the detection of B-modes.Comment: 16 page
Optical bistability in Er-Yb co-doped phosphate glass microspheres at room temperature
We experimentally demonstrate optical bistability in Er3+-Yb3+ phosphate
glass microspheres at 295 K. Bistability is associated with both Er3+
fluorescence and lasing behavior, and chromatic switching. The chromatic
switching results from an intrinsic mechanism exploiting the thermal coupling
of closely-spaced energy levels, and occurs simultaneously with the intensity
switching. A contrast ratio of 3.2 has been obtained for chromatic switching,
and the intensity switching shows ratios of 2.4 for 550 nm and, 1.8 for the 660
nm fluorescence emissions, and 11 for the IR lasing at 1.5 um. Concurrent with
these observations, we investigate a temperature dependent absorption of pump
power which exhibits bistable behavior. The influences of the host matrix on
lasing and fluorescence mechanisms are highlighted.Comment: 22 pages, 6 figure
Elasticity and viscosity of ice measured in the experiment on wave propagation below the ice in HSVA ice tank
An experiment on the propagation of flexural-gravity waves was performed in the HSVA ice tank in 2018. Physical characteristics of the water-ice system were measured in different locations in the tank during the tests, with several sensors deployed in the water, on the ice and
in the air. Periodical waves with frequencies of 0.5-1.5 Hz were generated by HSVA wave maker during 10 min in each test. The phase speeds and wave damping associated with anelastic deformations of ice were analyzed in the paper. Elastic modulus of ice was calculated for each wave period from the dispersion equation of flexural gravity waves where measured values of wave frequencies and wave speeds were substituted. Viscous coefficient of ice was calculated after the analysis of wave damping. Obtained values have relatively big dispersion which can be explained by natural variability of ice properties
Laboratory Investigations of the Bending Rheology of Floating Saline Ice and Physical Mechanisms of Wave Damping In the HSVA Hamburg Ship Model Basin Ice Tank
An experimental investigation of flexural-gravity waves was performed in the Hamburg Ship Model Basin HSVA ice tank. Physical characteristics of the water-ice system were measured in several locations of the tank with a few sensors deployed in the water and on the ice during the tests. The three-dimensional motion of ice was measured with the optical system Qualisys; water pressure was measured by several pressure sensors mounted on the tank wall, in-plane deformations of the ice and the temperatures of the ice and water were measured by fiber optic sensors; and acoustic emissions were recorded with compressional crystal sensors. The experimental setup and selected results of the tests are discussed in this paper. Viscous-elastic model (Burgers material) is adopted to describe the dispersion and attenuation of waves propagating below the ice. The elastic modulus and the coefficient of viscosity are calculated using the experimental data. The results of the measurements demonstrated the dependence of wave characteristics from the variability of ice properties during the experiment caused by the brine drainage. We showed that the cyclic motion of the ice along the tank, imitating ice drift, and the generation of under ice turbulence cause an increase of wave damping. Recorded acoustic emissions demonstrated cyclic microcracking occurring with wave frequencies and accompanying bending deformations of the ice. This explains the viscous and anelastic rheology of the model ice
Measurements of Polyatomic Molecule Formation on an Icy Grain Analog Using Fast Atoms
Carbon dioxide has been produced from the impact of a monoenergetic O(P-3) beam upon a surface cooled to 4.8 K and covered with a CO ice. Using temperature-programmed desorption and mass spectrometer detection, we have detected increasing amounts of CO2 formation with O(P-3) energies of 2, 5, 10, and 14 eV. This is the first measurement of polyatomic molecule formation on a surface with superthermal atoms. The goal of this work is to detect other polyatomic species, such as CH3OH, which can be formed under conditions that simulate the grain temperature, surface coverage, and superthermal atoms present in shock-heated circumstellar and interstellar regions
Upconversion channels in Er3+:ZBLALiP fluoride glass microspheres
We present results on the realization of a multicolour microspherical glass light source fabricated from the erbium doped fluoride glass ZBLALiP. Whispering gallery mode lasing and upconversion processes give rise to laser and fluorescent emissions at multiple wavelengths from the ultraviolet to the infrared. Thirteen discrete emissions ranging from 320 to 849 nm have been observed in the upconversion spectrum. A Judd-Ofelt analysis was performed to calculate the radiative properties of Er3+:ZBLALiP microspheres, including the radiative transition probabilities, the electric dipole strengths, the branching ratios and the radiative lifetimes of the transitions involved. We have also identified the primary processes responsible for the generation of the observed wavelengths and have shown that this material has an improved range of emissions over other erbium doped fluoride glasses
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