High speed single pixel imaging with advanced microLED digital light projector

We demonstrate high speed single pixel imaging using an advanced microLED-on-CMOS array. We show 128x128 pixel image reconstruction at an effective frame rate of 3.8fps and lower resolution reconstructions at over 120fps. The method is demonstrated to be compatible with common compressive imaging techniques

Rock cutting with an actuated disc: An experimental study

Actuated Disc Cutter is an undercutting disc, which is dynamically actuated while being dragged across the rock surface. In simple terms, undercutting discs are roller disc cutters that are used like drag tools to undercut rocks. This mechanism allows to combine the robustness of a roller disc (low wear rate) with the effectiveness of a drag tool (low cutting forces). Even though various realizations of the undercutting concept and actuated cutters exist in equipments designed to mechanically excavate hard rocks, the rock failure mechanism and its influencing factors are still not well understood for this class of cutting tools. This paper reports an experimental study of an actuated cutting process, which was designed to evaluate a recently proposed kinematics-based model. This model leads to a prediction of the force variation on the cutter during an activation cycle, assuming either ductile or brittle failure of the rock. Experiments were conducted using CSIRO's actuated disc cutting test-unit, dubbed as Wobble, to test the theoretical predictions at various operating conditions. The excellent agreement between the model predictions and Wobble experimental data provides strong support for the theoretical model and the assumed laws governing the cutting process

Production of a high-velocity water slug using an impacting technique

A pulsed water jet consists of a series of discrete water slugs travelling at high velocity. Immediately after striking a target, these slugs apply high-intensity, short-duration transient stress pulses reaching an amplitude known as the water hammer pressure, followed by low-intensity, long-duration stationary stress at a lower stagnation pressure. The magnitude and duration of the water hammer and stagnation pressures are controlled by the size and quality of the water slugs. The use of water jets for rock cutting in mining operations is a centuries-old technology; however, practical methods for producing high-energy water slugs repeatedly have proven difficult. This can be partly due to the fact that the geometrical properties of a jet and so its effectiveness in creating damage is controlled and influenced by the method that is employed to generate the water slugs. This paper investigates the quality of a single water slug produced using an impacting technique where a hammer strikes a piston, resting on top of a water-filled chamber. The coherence and integrity of the jet core was of concern in this study. The impact impulse of the formed water jet was measured in a Kel-F target material using an embedded PVDF (Polyvinylidene fluoride) shock gauge. The recorded stress waveform was then used to determine the unity and endurance of the water slug stream once travelled through air