Browse Articles

On the Relationship Between Viscosity and Surface Tension

Wei et al. | Sep 16, 2014

On the Relationship Between Viscosity and Surface Tension

Surface tension and viscosity are both measures of how "sticky" a liquid is, but are they related? The authors here investigate the surface tension and viscosity of mixtures of water with different concentrations of agar agar, flour, or detergent. Surprisingly, they find that the least viscous mixtures had the strongest surface tensions, indicating that the two properties are not linked.

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Changing the surface properties of the backside of a silicon wafer to repel oil and prevent particle binding

Choi et al. | Feb 14, 2025

Changing the surface properties of the backside of a silicon wafer to repel oil and prevent particle binding

Wafers, essential in microchip production, can develop issues like leveling problems and wafer slip due to the formation of silanol bonds on their backside, which attract silica particles and oil. Authors tested addressing this issue with a coating of [acetoxy(polyethyleneoxy)propyl]triethoxysilane (APTS) applied to the wafer’s backside, preventing particle binding and oil adherence.

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The Effects of Atmospheric Attenuation on Cosmic Ray Muons: How is Surface Level Cosmic Ray Muon Flux Affected by Atmospheric Attenuation?

Sun et al. | Sep 11, 2021

The Effects of Atmospheric Attenuation on Cosmic Ray Muons: How is Surface Level Cosmic Ray Muon Flux Affected by Atmospheric Attenuation?

Cosmic rays are high-energy astronomical particles originating from various sources across the universe. Here, The authors sought to understand how surface-level cosmic-ray muon flux is affected by atmospheric attenuation by measuring the variation in relative muon-flux rate relative to zenith angle, testing the hypothesis that muons follow an exponential attenuation model. The attenuation model predicts an attenuation length of 6.3 km. This result implies that only a maximum of 24% of muons can reach the Earth’s surface, due to both decay and atmospheric interactions.

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Cathodal Galvanotaxis: The Effect of Voltage on the distribution of Tetrahymena pyriformis

Zheng et al. | Jun 10, 2019

Cathodal Galvanotaxis: The Effect of Voltage on the distribution of <em>Tetrahymena pyriformis</em>

The surface of the unicellular eukaryote, Tetrahymena pyriformis, is covered with thousands of hair-like cilia. These cilia are very similar to cilia of the human olfactory and respiratory tracts making them model organisms for studying cilia function and pathology. The authors of this study investigated the effect of voltage on T. pyriformis galvanotaxis, the movement towards an electrical stimulus. They observed galvanotaxis towards the cathode at voltages over 4V which plateau, indicating opening of voltage gated-ion channels to trigger movement.

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A model for angle evolution in conical piles formed using the fixed funnel method

Capaldi et al. | Jul 20, 2026

A model for angle evolution in conical piles formed using the fixed funnel method

When granular materials are poured onto a surface, they form conical piles whose slopes increase before reaching a stable angle of repose. We found that this angle evolution follows a previously unrecognized two-phase exponential growth pattern that is conserved across granular materials with diverse particle properties. The parameters of this model correlate with particle friction and are influenced by deposition conditions, providing a quantitative framework for describing pile formation.

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