Electrodes for sealed secondary batteries

Self-supporting membrane electrode structures, in which active ingredients and graphite are incorporated in a polymeric matrix, improve performance of electrodes in miniature, sealed, alkaline storage batteries

Aerodynamic configuration development of the highly maneuverable aircraft technology remotely piloted research vehicle

The aerodynamic development of the highly maneuverable aircraft technology remotely piloted research vehicle (HiMAT/RPRV) from the conceptual design to the final configuration is presented. The design integrates several advanced concepts to achieve a high degree of transonic maneuverability, and was keyed to sustained maneuverability goals while other fighter typical performance characteristics were maintained. When tests of the baseline configuration indicated deficiencies in the technology integration and design techniques, the vehicle was reconfigured to satisfy the subcritical and supersonic requirements. Drag-due-to-lift levels only 5 percent higher than the optimum were obtained for the wind tunnel model at a lift coefficient of 1 for Mach numbers of up to 0.8. The transonic drag rise was progressively lowered with the application of nonlinear potential flow analyses coupled with experimental data

Bifurcation in Rotational Spectra of Nonlinear AB2_2 Molecules

A classical microscopic theory of rovibrational motion at high angular momenta in symmetrical non-linear molecules AB$_2$ is derived within the framework of small oscillations near the stationary states of a rotating molecule. The full-dimensional analysis including stretching vibrations has confirmed the existence of the bifurcation predicted previously by means of the rigid-bender model. The formation of fourfold energy clusters has already been experimentally verified for H$_2$Se and it has been demonstrated in fully-dimensional quantum mechanical calculations using the MORBID computer program. We show in the present work that apart from the level clustering, the bifurcation produces physically important effects including molecular symmetry-breaking and a transition from the normal mode to the local mode limit for the stretching vibrations due to rovibrational interaction. The application of the present theory with realistic molecular potentials to the H$_2$Te, H$_2$Se and H$_2$S hydrides results in predictions of the bifurcation points very close to those calculated previously. However for the lighter H$_2$O molecule we find that the bifurcation occurs at higher values of the total angular momentum than obtained in previous estimations. The present work shows it to be very unlikely that the bifurcation in H$_2$O will lead to clustering of energy levels. This result is in agreement with recent variational calculations.Comment: latex, 19 pages including 2 figures provided as *.uu fil

Implementing Racing AI using Q-Learning and Steering Behaviours

Artificial intelligence has become a fundamental component of modern computer games as developers are producing ever more realistic experiences. This is particularly true of the racing game genre in which AI plays a fundamental role. Reinforcement learning (RL) techniques, notably Q-Learning (QL), have been growing as feasible methods for implementing AI in racing games in recent years. The focus of this research is on implementing QL to create a policy which the AI agents to utilise in a racing game using the Unity 3D game engine. QL is used (offline) to teach the agent appropriate throttle values around each part of the circuit whilst the steering is handled using a predefined racing line. Two variations of the QL algorithm were implemented to examine their effectiveness. The agents also make use of Steering Behaviours (including obstacle avoidance) to ensure that they can adapt their movements in real-time against other agents and players. Initial experiments showed that both types performed well and produced competitive lap times when compared to a player

Resonances in rotationally inelastic scattering of OH(X2ΠX^2\Pi) with helium and neon

We present detailed calculations on resonances in rotationally and spin-orbit inelastic scattering of OH ($X\,^2\Pi, j=3/2, F_1, f$) radicals with He and Ne atoms. We calculate new \emph{ab initio} potential energy surfaces for OH-He, and the cross sections derived from these surfaces compare favorably with the recent crossed beam scattering experiment of Kirste \emph{et al.} [Phys. Rev. A \textbf{82}, 042717 (2010)]. We identify both shape and Feshbach resonances in the integral and differential state-to-state scattering cross sections, and we discuss the prospects for experimentally observing scattering resonances using Stark decelerated beams of OH radicals.Comment: 14 pages, 15 Figure

Investigation of model validity for numerical survivability testing of WECs

This paper investigates the applicability of two numerical models to assess the survivability of Wave Energy Converters (WECs). Simulations using both a fully nonlinear Navier-Stokes solver (based on OpenFOAM) and WaveDyn (a linear time-domain model for multi-body interactions) are compared with physical experiments involving a free-floating buoy with a single mooring line. Events in which survivability is a concern are modelled using the focus wave-group NewWave. Two wave-groups (one steeper than the other) are used to identify the validity of each numerical model as a function of wave steepness. By taking into account the CPU cost and model validity, the range of applicability for both models is discussed. This constitutes the first step in future work: coupling the two numerical models to form an efficient modelling tool that benefits from the computational efficiency of WaveDyn while including the fidelity of a Navier-Stokes solver when required; therefore providing valuable information for WEC developers

Dissipative Landau-Zener transitions of a qubit: bath-specific and universal behavior

We study Landau-Zener transitions in a qubit coupled to a bath at zero temperature. A general formula is derived that is applicable to models with a non-degenerate ground state. We calculate exact transition probabilities for a qubit coupled to either a bosonic or a spin bath. The nature of the baths and the qubit-bath coupling is reflected in the transition probabilities. For diagonal coupling, when the bath causes energy fluctuations of the diabatic qubit states but no transitions between them, the transition probability coincides with the standard LZ probability of an isolated qubit. This result is universal as it does not depend on the specific type of bath. For pure off-diagonal coupling, by contrast, the tunneling probability is sensitive to the coupling strength. We discuss the relevance of our results for experiments on molecular nanomagnets, in circuit QED, and for the fast-pulse readout of superconducting phase qubits.Comment: 16 pages, 8 figure

Degenerate Landau-Zener model: Exact analytical solution

The exact analytical solution of the degenerate Landau-Zener model, wherein two bands of degenerate energies cross in time, is presented. The solution is derived by using the Morris-Shore transformation, which reduces the fully coupled system to a set of independent nondegenerate two-state systems and a set of decoupled states. Due to the divergence of the phase of the off-diagonal element of the propagator in the original Landau-Zener model, not all transition probabilities exist for infinite time duration. In general, apart from some special cases, only the transition probabilities between states within the same degenerate set exist, but not between states of different sets. An illustration is presented for the transition between the magnetic sublevels of two atomic levels with total angular momenta J=2 and 1