Multiobjective optimization for flapping foil hydrodynamics with a multitask and multifidelity approach.

We develop a multitask and multifidelity Gaussian process (MMGP) model to accurately predict and optimize the multiobjective performance of a flapping foil while minimizing the cost of high-fidelity data. Through a comparison of three kernels, we have selected and applied the spectral mixture kernel and validated the robustness and effectiveness of a multiacquisition function. To effectively incorporate data with varying levels of fidelity, we have adopted a linear prior formula-based multifidelity framework.

A probability distribution model for the compressive strength of micro thin-walled hollow glass beads under uniform pressure.

Because of their many excellent properties, hollow glass beads (HGBs) are widely used in composite materials; stealth coatings; the aerospace field; the deep-sea field; electrical, thermal and sound insulation materials and military explosives. However, there is currently no method for predicting the strength of HGBs. This paper proposes a probability distribution model for the compressive strength of micro thin-walled HGBs under uniform pressure.

Impact of film thickness in laser-induced periodic structures on amorphous Si films.

We report self-organized periodic nanostructures on amorphous silicon thin films by femtosecond laser-induced oxidation. The dependence of structural periodicity on the thickness of silicon films and the substrate materials is investigated. The results reveal that when silicon film is 200 nm, the period of self-organized nanostructures is close to the laser wavelength and is insensitive to the substrates.

Multimaterial Embedded 3D Printing of Composite Reinforced Soft Actuators.

Soft pneumatic actuators (SPAs) have attracted enormous attention in the growing field of robotics. Among different SPAs, composite reinforced actuators (CRAs) are widely used because of their simple structure and high controllability. However, multistep molding, a time-consuming method, is still the predominant fabrication method.

Data-driven multi-joint waveguide bending sensor based on time series neural network.

Due to the bulky interrogation devices, traditional fiber optic sensing system is mainly connected by wire or equipped only for large facilities. However, the advancement in neural network algorithms and flexible materials has broadened its application scenarios to bionics. In this paper, a multi-joint waveguide bending sensor based on color dyed filters is designed to detect bending angles, directions and positions.

Design of a Practical Metal-Made Cold Isostatic Pressing (CIP) Chamber Using Finite Element Analysis.

The fast development of deep-ocean engineering equipment requires more deep-ocean pressure chambers (DOPCs) with a large inner diameter and ultra-high-pressure (UHP). Using the pre-stressed wire-wound (PSWW) concept, cold isostatic pressing (CIP) chambers have become a new concept of DOPCs, which can provide 100% performance of materials in theory. This paper aims to provide a comprehensive design process for a practical metal-made CIP chamber.

Review of Underwater Sensing Technologies and Applications.

As the ocean development process speeds up, the technical means of ocean exploration are being upgraded. Due to the characteristics of seawater and the complex underwater environment, conventional measurement and sensing methods used for land are difficult to apply in the underwater environment directly. Especially for the seabed topography, it is impossible to carry out long-distance and accurate detection via electromagnetic waves.

Disruption-Based Multiobjective Equilibrium Optimization Algorithm.

Nature-inspired computing has attracted huge attention since its origin, especially in the field of multiobjective optimization. This paper proposes a disruption-based multiobjective equilibrium optimization algorithm (DMOEOA). A novel mutation operator named layered disruption method is integrated into the proposed algorithm with the aim of enhancing the exploration and exploitation abilities of DMOEOA.

Complete Genome Sequence of Strain 29R7-12, a Piezophilic Bacterium Isolated from Coal-Bearing Sediment 2.4 Kilometers below the Seafloor.

Here, we report the genome sequence of strain 29R7-12, a piezophilic bacterium isolated from coal-bearing sediment down to ~2.4 km below the ocean floor in the northwestern Pacific. The strain is a Gram-positive spore-forming bacterium, closely related to within the phylum This is the first complete genome sequence of a strain from the deep biosphere.

First Complete Genome Sequence of Strain 15R, a Marine Lactobacillus Isolated from Coal-Bearing Sediment 2.0 Kilometers below the Seafloor, Determined by PacBio Single-Molecule Real-Time Technology.

strain 15R is a facultatively anaerobic heterotrophic lactobacillus isolated from deep marine subsurface sediment nearly 2 km below the seafloor in the northwestern Pacific. We report here the first whole-genome sequence of strain 15R. The identified genome sequence has 2,767,908 bp, 35.

Radial and translational oscillations of an acoustically levitated bubble in aqueous ethanol solutions.

The radial and translational oscillations of a single cavitation bubble in a standing ultrasound wave were investigated experimentally at various driving acoustic pressures for aqueous ethanol solutions with different bulk molar fractions of ethanol range of 0-1.3 × 10(-3). The results show that both the lower and upper stability thresholds of the acoustic driving pressure decreased as the concentration of ethanol was increased.

Effect of alcohol on single-bubble sonoluminescence.

The driving parametric regions in frequency-amplitude space and the optimal parameters for single-bubble sonoluminescence (SBSL) in alcohol aqueous solutions are studied systematically by taking measurements of the spectrum and bubble dynamics. The experimental results show that with an increase in alcohol concentration, the region shrinks and shifts. The optimized parameters differ for alcohol solutions having different concentrations, and SBSL driven by fixed parameters dims quickly and is even destroyed immediately with the addition of a small amount of alcohol to pure water.

Microbubble sizing and shell characterization using flow cytometry.

Experiments were performed to size, count, and obtain shell parameters for individual ultrasound contrast microbubbles using a modified flow cytometer. Light scattering was modeled using Mie theory, and applied to calibration beads to calibrate the system. The size distribution and population were measured directly from the flow cytometer.

The correlation between acoustic cavitation and sonoporation involved in ultrasound-mediated DNA transfection with polyethylenimine (PEI) in vitro.

Previous studies have demonstrated that the efficiency of gene/drug delivery can be enhanced under ultrasound (US) exposure with the presence of US contrast agent microbubbles, due to the acoustic cavitation-induced sonoporation. However, obstacles still remain to achieve controllable sonoporation outcome. The general hypotheses guiding present studies were that inertial cavitation (IC) activities accumulated during US exposure could be quantified as IC dose (ICD) based on passive cavitation detection (PCD), and the assessment of sonoporation outcome should be correlated with ICD measurements.

Resolving the shape of a sonoluminescence pulse in sulfuric acid by the use of streak camera.

A streak camera is used to measure the shape of sonoluminescence pulses from a cavitation bubble levitated stably in a sulfuric acid solution. The shape and response to an acoustic pressure field of the sonoluminescence pulse in 85% by weight sulfuric acid are qualitatively similar to those in water. However, the pulse width in sulfuric acid is wider than that in water by over one order of magnitude.

Time-resolved spectra of single-bubble sonoluminescence in sulfuric acid with a streak camera.

The time-resolved spectra of single-bubble sonoluminescence (SBSL) in sulfuric acid have been observed with a streak camera after a spectrograph. The spectral center evolves from infrared to ultraviolet gradually within a SBSL duration, which corresponds to an increase of temperature. The peak temperature within one sonoluminescence (SL) duration is 5-9 times higher than the average temperature based on the average spectrum in our experiment.