Stable ultrahigh-density magneto-optical recordings using introduced linear defects

The stability of data bits in magnetic recording media at ultrahigh densities is compromised by thermal `flips' -- magnetic spin reversals -- of nano-sized spin domains, which erase the stored information. Media that are magnetized perpendicular to the plane of the film, such as ultrathin cobalt films or multilayered structures, are more stable against thermal self-erasure than conventional memory devices. In this context, magneto-optical memories seem particularly promising for ultrahigh-density recording on portable disks, and bit densities of $\sim$100 Gbit inch$^{-2}$ have been demonstrated using recent advances in the bit writing and reading techniques. But the roughness and mobility of the magnetic domain walls prevents closer packing of the magnetic bits, and therefore presents a challenge to reaching even higher bit densities. Here we report that the strain imposed by a linear defect in a magnetic thin film can smooth rough domain walls over regions hundreds of micrometers in size, and halt their motion. A scaling analysis of this process, based on the generic physics of disorder-controlled elastic lines, points to a simple way by which magnetic media might be prepared that can store data at densities in excess of 1 Tbit inch$^{-2}$.Comment: 5 pages, 4 figures, see also an article in TRN News at http://www.trnmag.com/Stories/041801/Defects_boost_disc_capacity_041801.htm

Selected Physical Properties of Jointed Goatgrass (Aegilops cylindrica Host.)

Selected physical properties of jointed goatgrass samples collected in western Nebraska and eastern Colorado were determined. Measured properties were spikelet dimensions (length 10.8 ± 0.35 mm; width 2.59 ± 0.25 mm), particle density (0.761 ± 0.016 g/m3), bulk density (351 ± 26.9 kg/m3), terminal velocity (301 ± 25.9 m/min), angle of repose (26.3 ± 0.286°), internal coefficient of friction (0.494 ± 0.007), and equilibrium moisture contents at 10% RH (6.56 ± 1.03% w.b.), 30% RH (7.43 ± 1.21% w.b.), 50% RH (9.01 ± 0.67% w.b.), 70% RH (11.89 ± 0.61% w.b.), and 90% RH (20.39 ± 2.38% w.b.). Jointed goatgrass had substantially lower particle density and bulk density values than those reported in the literature for hard red winter wheat

Mobile health for cancer in low to middle income countries: priorities for research and development.

The is the accepted manuscript of an article published in the European Journal of Cancer Care (Holeman, I., Evans, J., Kane, D., Grant, L., Pagliari, C. and Weller, D. (2014), Mobile health for cancer in low to middle income countries: priorities for research and development. European Journal of Cancer Care, 23: 750–756. doi: 10.1111/ecc.12250)Many current global health opportunities have less to do with new biomedical knowledge than with the coordination and delivery of care. While basic research remains vital, the growing cancer epidemic in countries of low and middle income warrants urgent action - focusing on both research and service delivery innovation. Mobile technology can reduce costs, improve access to health services, and strengthen health systems to meet the interrelated challenges of cancer and other noncommunicable diseases. Experience has shown that even very poor and remote communities that only have basic primary health care can benefit from mobile health (or 'mHealth') interventions. We argue that cancer researchers and practitioners have an opportunity to leverage mHealth technologies that have successfully targeted other health conditions, rather than reinventing these tools. We call for particular attention to human centred design approaches for adapting existing technologies to suit distinctive aspects of cancer care and to align delivery with local context - and we make a number of recommendations for integrating mHealth delivery research with the work of designers, engineers and implementers in large-scale delivery programmes

Selected Physical Properties of Jointed Goatgrass (Aegilops cylindrica Host.)

Selected physical properties of jointed goatgrass samples collected in western Nebraska and eastern Colorado were determined. Measured properties were spikelet dimensions (length 10.8 ± 0.35 mm; width 2.59 ± 0.25 mm), particle density (0.761 ± 0.016 g/m3), bulk density (351 ± 26.9 kg/m3), terminal velocity (301 ± 25.9 m/min), angle of repose (26.3 ± 0.286°), internal coefficient of friction (0.494 ± 0.007), and equilibrium moisture contents at 10% RH (6.56 ± 1.03% w.b.), 30% RH (7.43 ± 1.21% w.b.), 50% RH (9.01 ± 0.67% w.b.), 70% RH (11.89 ± 0.61% w.b.), and 90% RH (20.39 ± 2.38% w.b.). Jointed goatgrass had substantially lower particle density and bulk density values than those reported in the literature for hard red winter wheat

Thermal Degradation Kinetics of Distillers Grains and Solubles in Nitrogen and Air

The pyrolysis and oxidation kinetics of distillers grains and solubles were determined using thermogravimetric analysis. The starting temperature of pyrolysis and oxidation of distillers grains and solubles increased with the increase of heating rate and initial moisture content. The pyrolysis and oxidation of distillers grains and solubles were completed at 650°C and 850°C, respectively, which were independent of the heating rate and the initial moisture content. The residual weights of distillers grains and solubles after pyrolysis and oxidation were 27.15% and 5.49% of the original dry mass of distillers grains and solubles. Thermogravimetrical analysis data was used to determine kinetic parameters of the thermal degradation of distillers grains and solubles. Predicted dynamic residual weights of distillers grains and solubles during thermal degradation agreed well with experimental data. Keywords: biomass, distillers grains and solubles, kinetics, TGA, thermochemica

Dispersive magnetic excitations in the S=1 antiferromagnet Ba3_3Mn2_2O8_8

We present powder inelastic neutron scattering measurements of the S=1 dimerized antiferromagnet Ba$_3$Mn$_2$O$_8$. The $T=1.4$ K magnetic spectrum exhibits a spin-gap of $\Delta \approx 1.0$ meV and a dispersive spectrum with a bandwidth of approximately 1.5 meV. Comparison to coupled dimer models describe the dispersion and scattering intensity accurately and determine the exchange constants in Ba$_3$Mn$_2$O$_8$. The wave vector dependent scattering intensity confirms the proposed S=1 dimer bond. Temperature dependent measurements of the magnetic excitations indicate the presence of both singlet-triplet and thermally activated triplet-quintet excitations.Comment: 8 pages, 8 figures, Submitted to Physical Review B, Resubmited versio

Discrimination, labour markets and the Labour Market Prospects of Older Workers: What Can a Legal Case Teach us?

As governments become increasingly concerned about the fiscal implications of the ageing population, labour market policies have sought to encourage mature workers to remain in the labour force. The ‘human capital’ discourses motivating these policies rest on the assumption that older workers armed with motivation and vocational skills will be able to return to fulfilling work. This paper uses the post-redundancy recruitment experiences of former Ansett Airlines flight attendants to develop a critique of these expectations. It suggests that policies to increase older workers’ labour market participation will not succeed while persistent socially constructed age- and gender- typing shape labour demand. The conclusion argues for policies sensitive to the institutional structures that shape employer preferences, the competitive rationality of discriminatory practices, and the irresolvable tension between workers’ human rights and employers’ property rights

Zero Field precession and hysteretic threshold currents in spin torque oscillators with tilted polarizer

Using non-linear system theory and numerical simulations we map out the static and dynamic phase diagram in zero applied field of a spin torque oscillator with a tilted polarizer (TP-STO).We find that for sufficiently large currents, even very small tilt angles (beta>1 degree) will lead to steady free layer precession in zero field. Within a rather large range of tilt angles, 1 degree< beta <19 degree, we find coexisting static states and hysteretic switching between these using only current. In a more narrow window (1 degree<beta<5 degree) one of the static states turns into a limit cycle (precession). The coexistence of static and dynamic states in zero magnetic field is unique to the tilted polarizer and leads to large hysteresis in the upper and lower threshold currents for TP-STO operation.Comment: 5 pages, 4 figure

Hydrodynamic response of a submerged tunnel element suspended from a twin-barge under random waves

It is possible that the excessive dynamic responses of tunnel elements could jeopardize the safety and accuracy of installation procedures used during subsea tunnel construction. To investigate the motion characteristics of the tunnel element, experimental measurements of a moored tunnel element suspended from a twin-barge were conducted in a wave flume at a geometric scale of 1:50. A corresponding numerical model was developed to simulate the dynamic response of the tunnel-barge system in realistic sea conditions, using hydrodynamic parameters from a radiation/diffraction potential model. Multiple linear wave conditions and three immersion depths were tested. The results indicate that the motion response of the tunnel element increases with decreasing immersion depth, and the natural periods of the tunnel, barge and combined tunnel-barge system play key roles in the influence of wave conditions on the motions of the tunnel. It was found that the low-frequency motion of the tunnel element is large in small wave periods. The mooring system under such conditions needs to be considered carefully during system design in order to safely control the motions of the tunnel-barge system in energetic ocean environments.The work is supported by the National Natural Science Foundation of China (Grant No.11272079), the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 51221961) and the China Scholarship Council (award to Yang Can for 1 year’s study abroad at the University of Exeter)

Experimental and numerical investigation on coupled motion characteristics of a tunnel element suspended from a twin-barge

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordThe coupled motion characteristics of a tunnel element, which is suspended from a twin-barge and moored to the seabed during the installation process, has been investigated using a 1:50 scaled model. Response characteristics are obtained for multiple regular wave conditions and three different immersion depths. Experimental investigation includes studies to identify system properties of individual arrangements (tunnel, twin-barge) and for the coupled tunnel & twin-barge configuration. Investigation of motion characteristics includes i) experimental studies of the tunnel element from a fixed suspension point and barge, ii) experimental studies with and without a mooring arrangement from the tunnel element to the seabed, iii) experimental study of the fully coupled tunnel & twin-barge configuration, and iv) numerical investigation of the fully coupled tunnel & twin-barge configuration using a commercial fully dynamic mooring simulation software (OrcaFlex™). The experimental investigations were carried out in the State Key Laboratory of Coastal and Offshore Engineering at Dalian University of Technology (DUT), using the ‘6-D Measurement System’ (6D-UMS) to obtain six degree of motions for both the tunnel and twin-barge. For the numerical study hydrodynamic properties were obtained from the diffraction/radiation potential code WAMIT for simplified tunnel and twin-barge elements and used to derive fully coupled motion behavior using the time-domain mooring simulation software OrcaFlex™. The results are presented in order to provide insights into the motion characteristics for the different configurations studied. The main findings indicate that the sway and roll motions for the coupled tunnel & twin-barge configuration decrease with increasing wave incidence angle and immersion depths. The use of additional mooring lines to restrain the tunnel element to the seabed played a further role in reducing the motions of the tunnel element, particularly when subjected to large amplitude and long period waves.The study is supported by the National Natural Science Foundation of China (Grant No.11272079) and the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 51221961) and the China Scholarship Council (award to Yang Can for 1 year's study abroad at the University of Exeter). The corresponding author has been partly funded through EPSRC grant EP/R007519/1