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Motion tracking and analysis of spray water droplets studied by high-speed photography using an iPhone X

Geng et al. | Sep 11, 2021

Motion tracking and analysis of spray water droplets  studied by high-speed photography using an iPhone X

Smartphones are not only becoming an inseparable part of our daily lives, but also a low-cost, powerful optical imaging tool for more and more scientific research applications. In this work, smartphones were used as a low-cost, high-speed, photographic alternative to expensive equipment, such as those typically found in scientific research labs, to accurately perform motion tracking and analysis of fast-moving objects. By analyzing consecutive images, the speed and flight trajectory of water droplets in the air were obtained, thereby enabling us to estimate the area of the water droplets landing on the ground.

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The effect of viscous drag on damped simple harmonic motion

Michael Powell et al. | Sep 14, 2023

The effect of viscous drag on damped simple harmonic motion

Dynamic viscosity is a quantity that describes the magnitude of a fluid’s internal friction or thickness. Traditionally, scientists measure this quantity by either calculating the terminal velocity of a falling sphere or the time a liquid takes to flow through a capillary tube. However, they have yet to conduct much research on finding this quantity through viscous damped simple harmonic motion. The present study hypothesized that the relationship between the dynamic viscosity and the damping coefficient is positively correlated.

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The effect of joint angle differences on blade velocity in elite and novice saber fencers: A kinematic study

Greene et al. | Mar 02, 2023

 The effect of joint angle differences on blade velocity in elite and novice saber fencers: A kinematic study

Here, recognizing that years of training in saber fencing could expectedly result in optimized movements that result in elite skill levels, the authors used motion tracking and statistical analysis to assess the difference in velocity and blade tip velocity of novice and elite fencers during a vertical blade thrust. They found statistically significant differences in blade tip velocity and elbow joint angle kinematics.

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Building an affordable model wave energy converter using a magnet and a coil

Choy et al. | Jul 05, 2023

Building an affordable model wave energy converter using a magnet and a coil
Image credit: Joshua Smith

Here, seeking to identify a method to locally produce and capture renewable energy in Hawai'i and other island communities, the authors built and tested a small-scale model wave energy converter. They tested various configurations of a floated magnet surrounded by a wire coal, where the motion of the magnet due to a wave results in induction current in the coil. While they identified methods to increase the voltage and current generated, they also found that corrosion results in significant deterioration.

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Assessing CDK5 as a Nanomotor for Chemotactic Drug Delivery

Jiang et al. | Sep 08, 2022

Assessing CDK5 as a Nanomotor for Chemotactic Drug Delivery

Enzyme chemotaxis is a thermodynamic phenomenon in which enzymes move along a substrate concentration gradient towards regions with higher substrate concentrations and can be used to steer nanovehicles towards targets along natural substrate concentrations. In patients with Alzheimer’s disease, a gradient of tau protein forms in the bloodstream. Tau protein is a substrate of the enzyme CDK5, which catalyzes the phosphorylation of tau protein and can travel using chemotaxis along tau protein gradients to increasing concentrations of tau and amyloid-beta proteins. The authors hypothesized that CDK5 would be able to overcome these barriers of Brownian motion and developed a quantitative model using Michaelis-Menten kinetics to define the necessary parameters to confirm and characterize CDK5’s chemotactic behavior to establish its utility in drug delivery and other applications.

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The velocity of white dwarf stars relates to their magnitude

Glazer et al. | Jun 30, 2023

The velocity of white dwarf stars relates to their magnitude
Image credit: Jacub Gomez

Using the European Space Agency’s Gaia dataset, the authors analyzed the relationship between white dwarfs’ magnitudes and proper motions. They hypothesized that older white dwarf stars may have different velocities than younger ones, possibly that stars slow down as they age. They found that the white dwarfs in the dataset were substantially redder and higher magnitude (traits traditionally associated with older stars) as compared to their non-fast counterparts.

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