435 research outputs found
Synchronized single electron emission from dynamical quantum dots
We study synchronized quantized charge pumping through several dynamical
quantum dots (QDs) driven by a single time modulated gate signal. We show that
the main obstacle for synchronization being the lack of uniformity can be
overcome by operating the QDs in the decay cascade regime. We discuss the
mechanism responsible for lifting the stringent uniformity requirements. This
enhanced functionality of dynamical QDs might find applications in
nanoelectronics and quantum metrology.Comment: 4 pages, 3 figures, submitted to AP
Elastic precession of electronic spin states in interacting integer quantum Hall edge channels
We consider the effect of Coulomb interactions in the propagation of
electrons, prepared in arbitrary spin states, on chiral edge channels in the
integer quantum Hall regime. Electrons are injected and detected at the same
energy at different locations of the Hall bar, which is modeled as a chiral
Tomonaga-Luttinger liquid. The current is computed perturbatively in the
tunneling amplitudes, within a non-crossing approximation using exact solutions
of the interacting Green's functions. In the case of different channel
velocities, the spin precession effect is evaluated, and the role of
interaction parameters and wavevectors is discussed.Comment: 5 pages, 3 figure
Analysis of cricket ball type and innings on state level cricket batter's performance
Background: The aim of this investigation was to compare the type of cricket balls utilized and innings on cricket batting performance in the First-Class Australian competition.
Methods: Batting performance measures of 43 state level cricket batters were collected from two seasons of the Sheffield shield tournament (N = 60 games) that incorporated both Kookaburra™ (n = 30 games) and Duke™ (n = 30 games) cricket balls.
Results: First-innings batting performances were significantly greater for the average number of runs scored (37.5 ± 13.4 vs. 31.2 ± 11.3), balls faced (60.7 ± 26.2 vs. 49.9 ± 23.6), boundary 4s (3.8 ± 1.9 vs. 2.9 ± 1.4), and boundary 6s (0.2 ± 0.3 vs. 0.1 ± 0.3) scored per game (p < 0.05), as well as centuries scored (5.74 ± 8.56 vs. 1.49 ± 5.14%) compared to second innings performances (p < 0.05). There were no
differences for any batting performance measures as a result of ball type (p > 0.05). However, significantly more wickets were taken by pace bowlers during Duke™ ball games (85.0 ± 12.8 vs. 76.4 ± 13.9%), while relatively more wickets were taken by spin bowlers during Kookaburra™ ball games (14.2 ± 12.5 vs. 22.0 ± 14.1%; p < 0.05).
Conclusions: Cricket batting performance was comparable in games involving the Kookaburra™ or Duke™ ball. However, pace bowlers were more successful transferring
their skill to the Duke™ ball, while spin bowlers were more successful with the KB™ ball. Subsequently, batters may be able to effectively adapt their movement technique, and transfer their skill to the Duke™ ball conditions. Future research is suggested to examine the influence of the cricket playing surface’s deterioration on cricket batter’s interceptive performance
Physical, anthropometric and athletic movement qualities discriminate development level in a rugby league talent pathway
This study compared the physical, anthropometric and athletic movement qualities of talent identified rugby league (RL) players within a development pathway. From a total of 174 players, three developmental levels were defined: under 18 (U18; n = 52), under 20 (U20; n = 53), and state league (SL; n = 69). All players performed a test battery that consisted of five physical assessments, two anthropometric measurements and an athletic movement assessment. A multivariate analysis of variance modelled the main effect of developmental level (Three levels: U18, U20 and SL) on test criterion variables. Receiver operating characteristic (ROC) curves were then built for the criterion variables that showed a significant developmental level effect. A significant effect was noted (V = 0.775, F = 5.43, P <0.05), with the SL players outperforming their U18 and U20 counterparts for measures of body mass, peak and average lower limb power, double lunge (left side), single leg Romanian deadlift (left and right sides), the push up, and total athletic ability assessment score (P<0.05; d = 0.35 – 1.21). The ROC curves generated an area under the curve of greater than 65% for each test criterion, indicating greater than chance discrimination. These results highlight the physical, anthropometric and athletic movement qualities discriminant of development level within a rugby league talent pathway. Practitioners are encouraged to consider the thresholds from the ROC curves as an objective guide to assist with the development of physical performance qualities that may augment player progression in Australian rugby league
Interface modeling in incompressible media using level sets in Escript
We use a finite element (FEM) formulation of the level set method to model geological fluid flow problems involving interface propagation. Interface problems are ubiquitous in geophysics. Here we focus on a Rayleigh-Taylor instability, namely mantel plumes evolution, and the growth of lava domes. Both problems require the accurate description of the propagation of an interface between heavy and light materials (plume) or between high viscous lava and low viscous air (lava dome), respectively. The implementation of the models is based on Escript which is a Python module for the solution of partial differential equations (PDEs) using spatial discretization techniques such as FEM. It is designed to describe numerical models in the language of PDEs while using computational components implemented in C and C++ to achieve high performance for time-intensive, numerical calculations. A critical step in the solution geological flow problems is the solution of the velocity-pressure problem. We describe how the Escript module can be used for a high-level implementation of an efficient variant of the well-known Uzawa scheme. We begin with a brief outline of the Escript modules and then present illustrations of its usage for the numerical solutions of the problems mentioned above
Electronic structure and magnetic properties of cobalt intercalated in graphene on Ir(111)
Using a combination of photoemission and x-ray magnetic circular dichroism (XMCD), we characterize the growth and the electronic as well as magnetic structure of cobalt layers intercalated in between graphene and Ir(111). We demonstrate that magnetic ordering exists beyond one monolayer intercalation, and determine the Co orbital and spin magnetic moments. XMCD from the carbon edge shows an induced magnetic moment in the graphene layer, oriented antiparallel to that of cobalt. The XMCD experimental data are discussed in comparison to our results of first-principles electronic structure calculations. It is shown that good agreement between theory and experiment for the Co magnetic moments can be achieved when the local-spin-density approximation plus the Hubbard U (LSDA+U) is used
Generation of energy selective excitations in quantum Hall edge states
We operate an on-demand source of single electrons in high perpendicular
magnetic fields up to 30T, corresponding to a filling factor below 1/3. The
device extracts and emits single charges at a tunable energy from and to a
two-dimensional electron gas, brought into well defined integer and fractional
quantum Hall (QH) states. It can therefore be used for sensitive electrical
transport studies, e.g. of excitations and relaxation processes in QH edge
states
Editorial: Adapted sports:Wheeled-mobility, exercise and health
Editorial on the Research Topic Adapted sports: wheeled-mobility, exercise and health by Vegter RJK, Veeger DHEJ, Goosey-Tolfrey VL and Leicht CA. (2002) Front. Rehabilit. Sci. 3: 1015179. doi: 10.3389/fresc.2022.1015179.</p
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