Mechanism of the heat exchange promotion by superimposing the external sound wave in standing-wave thermoacoustic system

For improvement of energy conversion efficiency, sound wave is superimposed with a loudspeaker to the working fluid in the stack. By using this method the work-flow generation of the stack was enhanced. To analyze this enhancement mechanism, the thickness of the boundary layer and the heat exchange area in the stack are calculated from the view point of heat exchange circumstance. The effect of the heat exchange circumstance on the particle displacement and heat flow is investigated. As a result, it is confirmed that the superimposed sound wave improves the heat exchange circumstance and then the thermoacoustic phenomenon is enhanced.

Molecular dynamics study on single particle displacement damage of ZB InN

To evaluate single-particle initial displacement damage of InN, the MD method is used to simulate the cascades, where the energy of PKA (E PKA) ranges from 1 to 5 keV. From these results, we can find that high EPKA will increase Np and Ns of defects, and aggravate the damage of InN, which is more obvious in Frenkel pairs. The formation efficiency of vacancy and interstitial is influenced by antisite defects, thereby causing the difference between vacancies and interstitials for the same atomic type. About the distribution of InN defects, it is mainly caused by vacancy defects, indicating that vacancy damage occupies the main position in displacement damage.

Sediment Profile Imaging: Laboratory Study Into the Sediment Smearing Effect of a Penetrating Plate

Sediment profiling imaging (SPI) is a versatile and widely used method to visually assess the quality of seafloor habitats (e.g., around fish farms and oil and gas rigs) and has been developed and used by both academics and consultancy companies over the last 50 years. Previous research has shown that inserting the flat viewport of an SPI camera into the sediment can have an impact on particle displacement pushing oxygenated surface sediments to deeper sediment depths and making anthropogenically-disturbed sediment appear healthier than they may actually be. To investigate the particle displacement that occurs when a flat plate is inserted into seafloor sediments, a testing device, termed the SPI purpose-built sediment chamber (SPI-PUSH) was designed and used in a series of experiments to quantify smearing where luminophores were used to demonstrate the extent of particle displacement caused by a flat plate being pushed into the sediment. Here, we show that the plate of the SPI-PUSH caused significant smearing, which varied with sediment type and the luminophore grain size. The mean particle smearing measured directly behind the inserted plate was 2.9 ± 1.5 cm for mud sediments with sand-like luminophores, 4.3 ± 2.5 cm for fine sand sediments with sand-like luminophores and 1.9 ± 1.1 cm for medium sand sediments with mud-like luminophores. When the mean depth of particle smearing was averaged over a larger sediment volume (11 cm3) next to the inserted plate, substantial differences were seen between the plate-insertion experiments and controls highlighting the potential extent of smearing artefacts that may be produced when a SPI camera penetrates the seafloor. This experimental data shows that future studies using the SPI camera, or any other periscope-like device (e.g., planar optodes) need to acknowledge that smearing may be significant. Furthermore, it highlights that a correction factor may need to be applied to these data (e.g., the depth of apparent redox potential discontinuity layer) to correctly interpret SPI camera images and better determine the effect of anthropogenic impacts on seafloor habitats.

Establishment of a heart-on-a-chip microdevice based on human iPS cells for the evaluation of human heart tissue function

Human iPS cell (iPSC)-derived cardiomyocytes (CMs) hold promise for drug discovery for heart diseases and cardiac toxicity tests. To utilize human iPSC-derived CMs, the establishment of three-dimensional (3D) heart tissues from iPSC-derived CMs and other heart cells, and a sensitive bioassay system to depict physiological heart function are anticipated. We have developed a heart-on-a-chip microdevice (HMD) as a novel system consisting of dynamic culture-based 3D cardiac microtissues derived from human iPSCs and microelectromechanical system (MEMS)-based microfluidic chips. The HMDs could visualize the kinetics of cardiac microtissue pulsations by monitoring particle displacement, which enabled us to quantify the physiological parameters, including fluidic output, pressure, and force. The HMDs demonstrated a strong correlation between particle displacement and the frequency of external electrical stimulation. The transition patterns were validated by a previously reported versatile video-based system to evaluate contractile function. The patterns are also consistent with oscillations of intracellular calcium ion concentration of CMs, which is a fundamental biological component of CM contraction. The HMDs showed a pharmacological response to isoproterenol, a β-adrenoceptor agonist, that resulted in a strong correlation between beating rate and particle displacement. Thus, we have validated the basic performance of HMDs as a resource for human iPSC-based pharmacological investigations.

Application in Process Industry of the Solid Particles Displacement on a Flat Oscillating Surface

In this paper we present a series of obtained results from the analysis of the behavior of a solid particle on a flat oscillating surface, a process that is found in separation operations of a heterogeneous mixture of solid particles. In this study, the inclination angle of the flat surface (7 or 10 degrees) and the eccentric device speed (91, 244 and 405 rpm) were varied. The results are extracted from video analysis using two commercial video cameras (Sony DCR-SR 36) with a recording speed of 25 frames per second, using the SynthEyes and Mathcad processing software. The obtained results from the analysis helped us to extract data showing the movement on the three axes OX, OY and OZ, average travel distance, average moving time of the solid particle on working surface and average velocity of the solid particle displacement.