Designing Multi-Shape Dual-Gas Initial Conditions for the Study of Hydrodynamic Instabilities

The flow resulting from the rotation of a series of thin plates that initially separate two gases of different densities is analysed using Direct Numerical Simulations. The ninety degrees plates' rotation forms a vorticity shear layer and a density interface in between the tips of two neighbouring plates. Results of this study show that the shape of these layers strongly depends on the plate tip-based Reynolds number that can be varied thanks to a parametrisation of the plates' opening law. Different regimes are identified corresponding to single- or multi-mode initial interfaces, with or without the occurrence of starting vortices during the formation of the shear layer. The density interfaces resulting from this procedure are particularly well-suited to serve as initial conditions for the study of the Richtmyer-Meshkov instability-induced mixing. Results of this study also provide a description of vortex formation in stratified flows.

A True Full-Duplex IO (TFD-IO) with Background SI cancellation for High-Density Interfaces

In this work, we have proposed and experimentally demonstrated a true full-duplex IO (TFD-IO) for high-speed high-density interfaces. The proposed TFD-IO can be used as an independent module that converts a unidirectional IO/interconnect to a fully bidirectional IO/interconnect, to ideally double the throughput of the high-speed interface. The TFD-IO uses a correlation-based technique to cancel the self-interference (SI) and echoes adaptively in the background. The signals transmitted from the near-end and the far-end can use independent baud nm CMOS technology, and demonstrated with bidirectional throughputs of up to 12.8 Gb/s.

A True Full-Duplex IO (TFD-IO) with Background SI cancellation for High-Density Interfaces

In this work, we have proposed and experimentally demonstrated a true full-duplex IO (TFD-IO) for high-speed high-density interfaces. The proposed TFD-IO can be used as an independent module that converts a unidirectional IO/interconnect to a fully bidirectional IO/interconnect, to ideally double the throughput of the high-speed interface. The TFD-IO uses a correlation-based technique to cancel the self-interference (SI) and echoes adaptively in the background. The signals transmitted from the near-end and the far-end can use independent baud nm CMOS technology, and demonstrated with bidirectional throughputs of up to 12.8 Gb/s.

Scattering of radiofrequency waves by randomly modulated density interfaces in the edge of fusion plasmas

In the scrape-off layer and the edge region of a tokamak, the plasma is strongly turbulent and scatters the radiofrequency (RF) electromagnetic waves that propagate through this region. It is important to know the spectral properties of these scattered RF waves, whether used for diagnostics or for heating and current drive. The spectral changes influence the interpretation of the obtained diagnostic data, and the current and heating profiles. A full-wave, three-dimensional (3-D) electromagnetic code ScaRF (see Papadopoulos et al., J. Plasma Phys., vol. 85, issue 3, 2019, 905850309) has been developed for studying the RF wave propagation through turbulent plasma. ScaRF is a finite-difference frequency-domain (FDFD) method used for solving Maxwell's equations. The magnetized plasma is defined through the cold plasma by the anisotropic permittivity tensor. As a result, ScaRF can be used to study the scattering of any cold plasma RF wave. It can also be used for the study of the scattering of electron cyclotron waves in ITER-type and medium-sized tokamaks such as TCV, ASDEX-U and DIII-D. For the case of medium-sized tokamaks, there is experimental evidence that drift waves and rippling modes are present in the edge region (see Ritz et al., Phys. Fluids, vol. 27, issue 12, 1984, pp. 2956–2959). Hence, we have studied the scattering of RF waves by periodic density interfaces (plasma gratings) in the form of a superposition of spatial modes with varying periodicity and random amplitudes (see Papadopoulos et al., J. Plasma Phys., vol. 85, issue 3, 2019, 905850309). The power reflection coefficient (a random variable) is calculated for different realizations of the density interface. In this work, the uncertainty of the power reflection coefficient is rigorously quantified by use of the Polynomial Chaos Expansion (see Xiu & Karniadakis, SIAM J. Sci. Comput., vol. 24, issue 2, 2002, pp. 619–644) method in conjunction with the Smolyak sparse-grid integration (see Papadopoulos et al., Appl. Opt., vol. 57, issue 12, 2018, pp. 3106–3114), which is known as the PCE-SG method. The PCE-SG method is proven to be accurate and more efficient (roughly a 2-orders of magnitude shorter execution time) compared with alternative methods such as the Monte Carlo (MC) approach.

Enhanced thermoelectric performance of polycrystalline SnSe by compositing with layered Ti3C2Tx

Thermoelectric materials convert thermal energy into electricity directly. Constructing nanostructured composite architectures can be an effective strategy to develop thermoelectric performance. SnSe/Ti3C2Tx composite materials were synthesized through the electrostatic self-assembly method followed by spark plasma sintering. The interfaces introduced by Ti3C2Tx can scatter carriers effectively, thus increasing the Seebeck coefficients (S), finally, a high absolute S value of ~ 296.2 µV K− 1 was obtained at 773 K. At the same time, the high-density interfaces of SnSe/Ti3C2Tx composites enhance the phonon scattering, a low lattice thermal conductivity klat of 0.54 W m− 1 K− 1 was obtained in sample ω = 0.1%. Benefit from the elevated Seebeck coefficient and decreased thermal conductivity, a ZT of 0.1 was obtained in sample ω = 0.1% at 773 K along the pressing direction, compared with the pure SnSe, the thermoelectric performance improved by 68%. This research will provide a new way for the development of the thermoelectric properties of polycrystalline SnSe.

A True Full-Duplex IO (TFD-IO) with Background SI Cancellation for High-Density Interfaces

In this work, we have proposed and experimentally demonstrated a true full-duplex IO (TFD-IO) for high-speed high-density interfaces. The proposed TFD-IO can be used as an independent module that converts a unidirectional IO/interconnect to a fully bidirectional IO/interconnect, to ideally double the throughput of the high-speed interface. <br>The TFD-IO uses a correlation-based technique to cancel the self-interference (SI) adaptively in the background. The signals transmitted from the near-end and the far-end can use independent baud-rates and signaling schemes in a TFD-IO. A proof-of-concept design of the TFD-IO module has been fabricated in a 65 nm CMOS technology, and demonstrated with bidirectional throughputs of up to 12.8\,Gb/s.

A True Full-Duplex IO (TFD-IO) with Background SI Cancellation for High-Density Interfaces

In this work, we have proposed and experimentally demonstrated a true full-duplex IO (TFD-IO) for high-speed high-density interfaces. The proposed TFD-IO can be used as an independent module that converts a unidirectional IO/interconnect to a fully bidirectional IO/interconnect, to ideally double the throughput of the high-speed interface. <br>The TFD-IO uses a correlation-based technique to cancel the self-interference (SI) adaptively in the background. The signals transmitted from the near-end and the far-end can use independent baud-rates and signaling schemes in a TFD-IO. A proof-of-concept design of the TFD-IO module has been fabricated in a 65 nm CMOS technology, and demonstrated with bidirectional throughputs of up to 12.8\,Gb/s.