In this study, we propose a design method of semi-active control systems by using a variable inertia mass damper (IMD) for structural systems subject to seismic disturbances. The variable IMD is a semi-active vibratio...
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The acoustic response of microbubbles (MBs) depends on their resonance frequency, which is dependent on MB size and shell properties. Monodisperse MBs with tunable shell properties are thus desirable for optimizing an...
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The acoustic response of microbubbles (MBs) depends on their resonance frequency, which is dependent on MB size and shell properties. Monodisperse MBs with tunable shell properties are thus desirable for optimizing and controlling MB behavior in acoustics applications. By utilizing a novel microfluidic method that uses lipid concentration to control MB shrinkage, we generate monodisperse MBs of four different initial diameters at three lipid concentrations (5.6, 10.0, and 16.0 mg/mL) in the aqueous phase. Following shrinkage, we measure MB resonance frequency and determine its shell stiffness and viscosity. The study demonstrates that we can generate monodisperse MBs of specific sizes and tunable shell properties by controlling MB initial diameter and aqueous phase lipid concentration. Our results indicate that the resonance frequency increases by 180-210% with increasing lipid concentration (from 5.6 to 16.0 mg/mL) while bubble diameter is kept constant. Additionally, we find that the resonance frequency decreases by 260-300% with increasing MB final diameter (from 5 to 12 μm), while lipid concentration is held constant. For example, our results depict that the resonance frequency increases by ~195% with increasing lipid concentration from 5.6 to 16.0 mg/mL, for ~11 μm final diameter MBs. Additionally, we find that the resonance frequency decreases by ~275% with increasing MB final diameter from 5 to 12 μm, when we use a lipid concentration of 5.6 mg/mL. We also determine that MB shell viscosity and stiffness increase with increasing lipid concentration and MB final diameter, and the level of change depends on the degree of shrinkage experienced by MB. Specifically, we find that by increasing the concentration of lipids from 5.6 to 16.0 mg/mL, the shell stiffness and viscosity of ~11 μm final diameter MBs increase by ~400% and ~200 %, respectively. This study demonstrates the feasibility of fine-tuning the MB acoustic response to ultrasound by tailoring MB initial
Soft, amorphous solids such as tissues, foams, and emulsions are composed of deformable particles. However, the effect of single-particle deformability on the collective behavior of soft solids is still poorly underst...
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Soft, amorphous solids such as tissues, foams, and emulsions are composed of deformable particles. However, the effect of single-particle deformability on the collective behavior of soft solids is still poorly understood. We perform numerical simulations of two-dimensional jammed packings of explicitly deformable particles to study the mechanical response of model soft solids. We find that jammed packings of deformable particles with excess shape degrees of freedom possess low-frequency quartic vibrational modes that stabilize the packings even though they possess fewer interparticle contacts than the nominal isostatic value. Adding intraparticle constraints can rigidify the particles, but these particles undergo a buckling transition and gain an effective shape degree of freedom when their preferred perimeter is above a threshold value. We find that the mechanical response of jammed packings of deformable particles with shape degrees of freedom differs significantly from that of jammed packings of rigid-shape particles, which emphasizes the importance of particle deformability in modeling soft solids.
The objective of this study is to create a services design of E-Government system that can help Indonesian government to resolve some problems such as diversity platform and application. It causes the island applicati...
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Hydrogel beads, composed of polymers, possess the ability to absorb substantial quantities of water simultaneously and gradually release it in dry conditions. In this work, hydrogel beads were synthesized using sodium...
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We present the theory, design, and proof-of-concept demonstration of a tumor-derived extracellular vesicle (EV) detection platform. Our platform detects EVs displaying specific surface antigens by electronically measu...
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This study reports grain boundary (GB) energy calculations for 46 symmetric-tilt GBs in α-iron using molecular mechanics based on an artificial neural network (ANN) potential and compares the results with calculation...
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Nature has evolved over several billion years, optimizing structural efficiency through the use of repeating unit cells called lattice structures that have inspired researchers in mimicking such changes in real-life a...
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In the current study, thermal patterns and flow resistance in a heat exchange tube equipped with a curved-wing tape (CWT) vortex generator were experimentally analyzed to boost performance. A range of Reynolds numbers...
In the current study, thermal patterns and flow resistance in a heat exchange tube equipped with a curved-wing tape (CWT) vortex generator were experimentally analyzed to boost performance. A range of Reynolds numbers (Re) from 4130 to 25,370 was utilized in the experiment. The curved wings were arranged in forward array patterns for pitch length ratios (P/D = PR = 2.5, 2, and 1.5) and three wing attack angles (α = 10°, 20°, and 30°). The friction factor, f, and the Nusselt number, Nu, were utilized to quantify the pressure loss and heat transmission caused by the CWT insertion. The measured data reveal that utilizing the CWT resulted in a roughly 2.55-4.37 times greater increase in Nu than the smooth tube, whereas the rise in f is approximately 7.36-46.9 times. Raising the α value causes the Nu and f to trend upward, but increasing PR causes them to trend downward. The CWT’s maximal thermal performance is approximately 1.58 at α = 10° and PR = 1.5. Correlations for f and Nu in the functional form of the CWT parameters have also been established.
Understanding the dynamical behavior of complex systems from their underlying network architectures is a long-standing question in complexity theory. Therefore, many metrics have been devised to extract network featur...
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