Universality of collapsing two-dimensional self-avoiding trails

Results of a numerically exact transfer matrix calculation for the model of Interacting Self-Avoiding Trails are presented. The results lead to the conclusion that, at the collapse transition, Self-Avoiding Trails are in the same universality class as the O(n=0) model of Blote and Nienhuis (or vertex-interacting self-avoiding walk), which has thermal exponent $\nu=12/23$, contrary to previous conjectures.Comment: Final version, accepted for publication in Journal of Physics A; 9 pages; 3 figure

Basic requirements of fuel-injection nozzles for quiescent combustion chambers

This report presents test results obtained during an investigation of the performance of a single-cylinder, high-speed, compression-ignition test engine when using multiple-orifice fuel-injection valve nozzles in which the number and the direction of the orifices were varied independently

Performance of a High-Speed Compression-Ignition Engine Using Multiple Orifice Fuel Injection Nozzles

This report presents test results obtained at the Langley Memorial Aeronautical Laboratory of the National Advisory Committee for Aeronautics during an investigation to determine the relative performance of a single-cylinder, high-speed, compression-ignition engine when using fuel injection valve nozzles with different numbers, sizes, and directions of round orifices. A spring-loaded, automatic injection valve was used, centrally located at the top of a vertical disk-type combustion chamber formed between horizontally opposed inlet and exhaust valves of a 5 inch by 7 inch engine

Projecting the carbon emissions from refrigeration used in the UK food industry to 2050

The impact to food cold chain greenhouse gas emissions from changes to population, climate, equipment efficiency, f-gas phase-downs, electrical grid carbon intensity and electrification of transport refrigeration up to 2050 were predicted using a 2019 baseline from a previous study. GHG emissions were projected to reduce by 98% from 2030 to 2050. This is due to decarbonisation of the electrical grid, electrification of diesel powered transport refrigeration units (TRUs) and f-gas phase down. Population and increased ambient temperature only have a marginal effect (7.2% increase to 2050). Although GHG emissions reduce, the electrical demand on the grid is projected to increase by 9.9% from 2030 to 2040 and then remain relatively stable. This is due to increased electrical demand as two thirds of HGV diesel TRUs are converted to electric

Self-oscillating control methods for the LCC current-output resonant converter

Abstract—A strategy for self-oscillating control of LCC current-output resonant converters, is presented, based on varying the phase-angle between the fundamental of the input voltage and current. Unlike other commonly employed control methodologies,the proposed technique is shown to provide a convenient, linear system input-output characteristic suitable for the design of regulators. The method is shown to have a similar effect as controlling the dc-link supply voltage, in terms of output-voltage/current control. The LCC converter variant is used as an application focus for demonstrating the presented techniques, with simulation and experimental measurements from a prototype converter being used to show the practical benefits. Third-order small and large-signal models are developed, and employed in the formulation of robust output-voltage and output-current control schemes. However, notably, the presented techniques are ultimately generic and readily applicable to other resonant converter variants

Prompt energization of relativistic and highly relativistic electrons during a substorm interval: Van Allen Probes observations

Abstract On 17 March 2013, a large magnetic storm significantly depleted the multi-MeV radiation belt. We present multi-instrument observations from the Van Allen Probes spacecraft Radiation Belt Storm Probe A and Radiation Belt Storm Probe B at ~6 Re in the midnight sector magnetosphere and from ground-based ionospheric sensors during a substorm dipolarization followed by rapid reenergization of multi-MeV electrons. A 50% increase in magnetic field magnitude occurred simultaneously with dramatic increases in 100 keV electron fluxes and a 100 times increase in VLF wave intensity. The 100 keV electrons and intense VLF waves provide a seed population and energy source for subsequent radiation belt enhancements. Highly relativistic (\u3e2 MeV) electron fluxes increased immediately at L* ~ 4.5 and 4.5 MeV flux increased \u3e90 times at L* = 4 over 5 h. Although plasmasphere expansion brings the enhanced radiation belt multi-MeV fluxes inside the plasmasphere several hours postsubstorm, we localize their prompt reenergization during the event to regions outside the plasmasphere. Key Points Substorm dynamics are important for highly relativistic electron energization Cold plasma preconditioning is significant for rapid relativistic energization Relativistic / highly relativistic electron energization can occur in \u3c 5 hrs

Design of an LCC current-output resonant converter for use as a constant current source

A methodology for the design of LCC resonant current-source converters, is presented. Unlike previous techniques, the resulting converter provides near constant steady-state output current over an extended load range when excited at the resonant frequency, through use of a self-oscillating controlle

Normalized analysis and design of LCC resonant converters

Abstract—A normalization of the LCC voltage-output resonant converter performance characteristics, in terms of the tank gain at resonance and the parallel-to-series-capacitor ratio, is presented. The resulting description is subsequently used for the derivation of a design procedure that incorporates the effects of diode losses and the finite charge/discharge time of the parallel capacitor. Unlike previously reported techniques, the resulting normalized behavior of the converter is used to identify design regions to facilitate a reduction in component electrical stresses, and the use of harmonics to transfer real power. Consideration of the use of preferred component values is also given. The underlying methodology is ultimately suitable for incorporation into a software suite for use as part of a rapid interactive design tool. Both simulation results and experimental measurements from a prototype converter are included to demonstrate the attributes of the proposed analysis and design methodologies

Discovery of A New Faint Radio SNR G108.2-0.6

A new faint and large shell-type radio Supernova Remnant (SNR) G108.2-0.6 has been discovered in the Canadian Galactic Plane Survey (CGPS). The SNR shows an elliptical shell-type structure at 1420 MHz, and has a 408-1420 MHz TT-plot spectral index of $\alpha$=-0.5$\pm$0.1 (S$_{\nu}$$\propto$$\nu$$^{\alpha}$), typical of a shell-type SNR. The remnant's flux density at 1420 MHz is 6.6$\pm$0.7 Jy, and at 408 MHz is 11.5$\pm$1.2 Jy. Both of these are corrected for compact sources. An integrated spectral index of $-0.45\pm$0.13 is determined. This new SNR has among the lowest surface brightness of any known remnant ($\Sigma$$_{1 GHz}$=2.4$\times10^{-22}$ W m$^{-2}$ Hz$^{-1}$ sr$^{-1}$). 21 cm Stokes Q and U CGPS data (plus preliminary Effelsberg Q and U maps) show some suggestive features that correlate with total power. \ion{H}{i} observations show structures associated with G108.2$-$0.6 in the radial velocity range $-$53 to $-$58 km s$^{-1}$, and indicate it is located in the Perseus arm shock at a distance of 3.2$\pm$0.6 kpc. At this distance the diameter of G108.2$-$0.6 is 58 pc. IRAS maps (12, 25, 60 and 100\mu m) of the new SNR show rich infrared emission surrounding G108.2$-$0.6.Comment: 10 pages, 6 figs, accepted by A&