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[Display omitted] • Effect of cavitation bubbles on bubble-particle interactions directly visualised. • Cavitation bubbles generated using a 20 kHz ultrasonic field. • Bubble-particles interactions facilitated using a continuous liquid recirculation. • Cavitation bubbles formed floatable particle clusters. • Particle clusters collected by millimetric size carrier bubbles. In this study, the role of cavitation bubbles in the bubble-particle interaction dynamics was investigated using high-speed imaging. A lab-scale conceptual flotation cell was designed involving an ultrasonic field with adjustable power output and a continuous liquid recirculation stream. Coarse size range hydrophobic glass Ballotini particles were suspended in the cell by the combined action of a confined vortex and turbulence created by periodic ultrasonic pulses. Ultrasonic pulses in the liquid medium led to the generation of numerous fine size range cavitation bubbles which were observed to form particle clusters. These particle clusters were observed attaching to relatively larger size carrier bubbles forming stable bubble-particles aggregates, which subsequently floated. It was noted that a favourable state of bubble-particle interactions was achievable to produce such stable bubble-particles aggregates by suitably controlling the input power and period of the applied ultrasonic pulse. [ABSTRACT FROM AUTHOR]

Neural implants have the potential to restore lost sensory function by electrically evoking the complex naturalistic activity patterns of neural populations. However, it can be difficult to predict and control evoked neural responses to simultaneous multi-electrode stimulation due to nonlinearity of the responses. We present a solution to this problem and demonstrate its utility in the context of a bidirectional retinal implant for restoring vision. A dynamically optimized stimulation approach encodes incoming visual stimuli into a rapid, greedily chosen, temporally dithered and spatially multiplexed sequence of simple stimulation patterns. Stimuli are selected to optimize the reconstruction of the visual stimulus from the evoked responses. Temporal dithering exploits the slow time scales of downstream neural processing, and spatial multiplexing exploits the independence of responses generated by distant electrodes. The approach was evaluated using an experimental laboratory prototype of a retinal implant: large-scale, high-resolution multi-electrode stimulation and recording of macaque and rat retinal ganglion cells ex vivo. The dynamically optimized stimulation approach substantially enhanced performance compared to existing approaches based on static mapping between visual stimulus intensity and current amplitude. The modular framework enabled parallel extensions to naturalistic viewing conditions, incorporation of perceptual similarity measures, and efficient implementation for an implantable device. A direct closed-loop test of the approach supported its potential use in vision restoration. [ABSTRACT FROM AUTHOR]

Presents information on a study which described an exact algorithm for solving output-encoding problem. Motivation behind studying an output encoding problem; Encoding algorithm for specified outputs; Encoding algorithm for outputs with do not cares; Conclusions.

In this paper, high-performance back-gated carbon nanotube field-effect transistors based on transferred aligned carbon nanotubes were fabricated and studies found that the on/off ratio can reach 107 and the current density can reach 1.6 μA/μm after electrical breakdown. In addition, chemical doping with hydrazine was used to convert the p-type aligned nanotube devices into n-type. These devices were further utilized to demonstrate various logic circuits, including p-type metal-oxide-semiconductor inverters, diode-loaded inverters, complementary metal-oxide-semiconductor inverters, NAND, and NOR gates. This approach could work as the platform for future nanotube-based nanoelectronics. [ABSTRACT FROM AUTHOR]

The guest editors introduce the articles in the special issue on Hot Chips. [ABSTRACT FROM PUBLISHER]

In multiphase particulate systems, the turbulence of the continuous phase (gas or liquid) is modulated due to interactions between the continuous phase and the suspended particles. Such phenomena are non-trivial in the essence that addition of a dispersed phase to a turbulent flow complicates the existing flow patterns depending on the physical properties of the particles leading to either augmentation or attenuation of continuous phase turbulence. In the present study, this aspect has been comprehensively analysed based on the available experimental data obtained from the well-studied turbulent flow systems such as channel and pipes, free jets and grids. Relevant non-dimensional parameters such as particle diameter to integral length scale ratio, Stokes number, particle volume fraction, particle momentum number, and particle Reynolds number have been utilised to characterise the reported turbulence modulation behavior. Some limitations of these commonly used dimensionless parameters to characterise turbulence modulation are discussed, and possible improvements are suggested. [ABSTRACT FROM AUTHOR]

The demands of future applications in computing (from self-driving cars to bioinformatics) overwhelm the projected capabilities of current electronic systems. The need to process unprecedented amounts of loosely structured data is driving the push for ultradense and fine-grained integration of traditionally off-chip components (e.g., sensors, memories) with energy-efficient computation units—all within a single chip. Monolithic 3-D integration is a leading approach for building such future systems, as it naturally enables ultradense connectivity between various heterogeneous technologies inside a single chip. This article discusses exciting recent progress toward realizing monolithic 3-D systems and elucidates key benefits that these new systems offer. Monolithic 3-D integration promises to enable the next wave of gains in performance (both energy and speed) for coming generations of applications as well as provides the means for developing rich additional functionalities such as sensing-immersed-in-computation that lie beyond the scope of traditional computing today. [ABSTRACT FROM AUTHOR]

A comprehensive review of the published literature regarding the computational fluid dynamics (CFD) modelling of the flotation process is presented. The detailed principles, mechanism and operation of the flotation process are discussed focusing mainly on the hydrodynamic aspect which is required for the successful operation of the flotation cell. The kinetic modelling of flotation process has been reviewed in detail in three major flotation equipment namely mechanically agitated flotation cell, flotation column and dissolved air flotation. The advances made in the modelling and simulations of the equipment have been critically analyzed. Specific emphasis is given on the bubble-particle interactions and the effect of turbulence on these interactions. An attempt has been made to correlate the model parameters with the turbulence parameters. A thorough discussion is presented to highlight strengths and weaknesses of currently used CFD models and the recent developments in the numerical simulation tools for better understanding of the process. Finally, recommendations have been made for the future progress based on the analysis of the previous work. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) have great potential for future high-performance and energy-efficient transistor technology. To realize this potential, methods to dope the CNTs need to be developed to achieve low parasitic resistance of the transistor. Two key issues present themselves: (a) understanding the doping mechanism of the various methods and (b) stability of the doping method. For instance, although studies on molybdenum oxide (MoOx) demonstrate its ability to heavily dope nanomaterials, the interaction between MoOx and the CNT is unclear. Here, we observe an unstable effect of MoOx on the CNT and demonstrate dielectric passivation as a means to preserve the doping strength. The semiconducting CNTs exhibit greater than 103× reduction in resistance after stably doped with MoOx. By exploiting the instability of MoOx, we delve deeper into clarifying the doping mechanism. The relationship between the time-dependent material property of MoOx and the change in the electrical measurements of CNT devices is investigated to study the role of work function in doping the CNTs. We conclude that the doping mechanism of MoOx on the CNT is due to bandgap modulation by charge transfer, which occurs due to the difference in work function between MoOx and the CNT. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bubble surface loading (BSL) governs flotation kinetics by influencing rise velocity. • Acoustic emission method promising for practical monitoring of BSL. • Effect of flow field on maximum BSL (mono or multilayer) not well understood. • Reduced rise velocity due to BSL empirically accounted through increased drag force. • Increasing BSL delays coalescence but effect of relative velocity less explored. In mineral flotation, surface loading dynamics of bubbles due to particle attachment and detachment in a turbulent environment is central to the understanding of separation kinetics of valuable minerals from gauge that governs the final product recovery. This review presents a comprehensive account of the current understanding of different bubble surface loading (BSL) measurement techniques both in quiescent liquid and typical flotation environment. It is noted that acoustic emission method is a potentially useful technique for online measurement of bubble surface loading in industrial systems although its translation to industry practice has not been satisfactory yet. From theoretical perspective, estimation of the BSL parameter is not quite straightforward due to limited understanding of the effect of surface loading on the flow field around the rising particle laden bubbles which governs the drag coefficient. Lack of knowledge in estimating drag coefficient affects estimation of rise velocity of the aggregates hence the recovery rate constant. It is also noted that bubble coalescence behaviour is delayed in presence of surface loading. Nevertheless, when coalescence occurs, it leads to loss of surface loading due to liberation of surface energy as oscillatory waves on bubble surfaces. Finally, a summary of the current challenges in this space is presented, and possible solutions are laid out to which future research endeavour should be directed. [ABSTRACT FROM AUTHOR]