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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Optimizing surface contact area and electrolyte type to develop a more effective rechargeable battery

Rajapakse et al. | Oct 27, 2024

Optimizing surface contact area and electrolyte type to develop a more effective rechargeable battery
Image credit: Rajapakse and Rajapakse 2024.

Rechargeable batteries are playing an increasingly prominent role in our lives due to the ongoing transition from fossil energy sources to green energy. The purpose of this study was to investigate variables that impact the effectiveness of rechargeable batteries. Alkaline (non-rechargeable) and rechargeable batteries share common features that are critical for the operation of a battery. The positive and negative electrodes, also known as the cathode and anode, are where the energy of the battery is stored. The electrolyte is what facilitates the transfer of cations and anions in a battery to generate electricity. Due to the importance of these components, we felt that a systematic investigation examining the surface area of the cathode and anode as well the impact of electrolytes with different properties on battery performance was justified. Utilizing a copper cathode and aluminum anode coupled with a water in salt electrolyte, a model rechargeable battery system was developed to test two hypotheses: a) increasing the contact area between the electrodes and electrolyte would improve battery capacity, and b) more soluble salt-based electrolytes would improve battery capacity. After soaking in an electrolyte solution, the battery was charged and the capacity, starting voltage, and ending voltage of each battery were measured. The results of this study supported our hypothesis that larger anode/cathodes surface areas and more ionic electrolytes such as sodium chloride, potassium chloride and potassium sulfate resulted in superior battery capacity. Incorporating these findings can help maximize the efficiency of commercial rechargeable batteries.

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Antibacterial Effects of Copper Surfaces

Mulukutla et al. | May 19, 2020

Antibacterial Effects of Copper Surfaces

This study examined the ability of copper and copper alloy surfaces to inhibit bacterial growth, which may be help prevent healthcare-associated infections. The authors exposed two non-pathogenic strains of bacteria to different metal plates for varying degrees of time and measured bacterial growth.

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Variations in Heat Absorption and Release of Earth Surfaces During Fall in Laramie, Wyoming

Ramesh et al. | Sep 08, 2020

Variations in Heat Absorption and Release of Earth Surfaces During Fall in Laramie, Wyoming

Here the authors investigate the contributions of man-made surfaces in Laramie, Wyoming to the Urban Heat Island (UHI) effect. Heat absorption and release by five surfaces were measured in the autumn of 2018. By recording temperatures of man-made and natural surfaces at early morning, mid-afternoon, and evening using an infrared thermometer, the authors determined that man-made surfaces retained more heat in fall than natural surfaces.

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Assessing the association between developed surface area and land surface temperature of urban areas

Ustin et al. | Nov 11, 2024

Assessing the association between developed surface area and land surface temperature of urban areas
Image credit: The authors

Almost all urban areas face the challenge of urban heat islands, areas with substantially hotter land surface temperatures than the surrounding rural areas. These areas are associated with worse air and water
quality, increased power outages, and increased heat-related illnesses. To learn more about these areas, Ustin et al. analyze satellite images of Cleveland neighborhoods to find out if there is a correlation between surface area development and surface temperature.

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Statistical evaluation of the effects of surface processing on aerospace fastener tested strength

Zeng et al. | Mar 31, 2023

Statistical evaluation of the effects of surface processing on aerospace fastener tested strength
Image credit: Robert Ruggiero

In the aerospace industry, various surface processing or coatings are widely used. However, no detailed research on the aerospace fastener tensile and double shear strength variation due to surface processing has been conducted. Thus, the purpose of this study was to systematically evaluate the effect of surface processing on the standard aerospace fastener's tensile and shear properties.

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