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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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Temperature and Precipitation Responses to a Stratospheric Aerosol Geoengineering Experiment Using the Community Climate System Model 4

Anderson et al. | Aug 19, 2014

Temperature and Precipitation Responses to a Stratospheric Aerosol Geoengineering Experiment Using the Community Climate System Model 4

We are changing our environment with steadily increasing carbon dioxide emissions, but we might be able to help. The authors here use a computer program called Community Climate System Model 4 to predict the effects of spraying small particles into the atmosphere to reflect away some of the sun's rays. The software predicts that this could reduce the amount of energy the Earth's atmosphere absorbs and may limit but will not completely counteract our carbon dioxide production.

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Focusing Sound Waves Using a Two-Dimensional Non-Linear System

Wehr et al. | Jul 07, 2014

Focusing Sound Waves Using a Two-Dimensional Non-Linear System

Sound waves can be amazingly powerful, especially when they work together. Here the authors create an “acoustic lens” that focuses sound waves on a single location. This makes the sound waves very powerful, capable of causing damage at a precise point. In the future, acoustic lenses like this could potentially be used to treat cancer by killing small tumors without surgery.

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What Can You See in the Dark? The Effects of Contrast, Light, and Age on Contrast Sensitivity in Low Light

Virostek et al. | Apr 25, 2014

What Can You See in the Dark? The Effects of Contrast, Light, and Age on Contrast Sensitivity in Low Light

Many of us take our vision for granted, but rarely do we measure how well we can see. In this study, the authors investigate the ability of people of different ages to read progressively fainter letters in dark light. They find that the ability to see in dim light drops drastically after age 30. The ability to read fainter letters worsens after age 30 as well. These findings should help inform lighting decisions everywhere from restaurants to road signs.

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Is Cloud Cover One of the Effects of Climate Change?

Crair et al. | Mar 27, 2014

Is Cloud Cover One of the Effects of Climate Change?

Climate change is one of the most controversial challenges humans face. Here the authors investigate the dual role of clouds - to reflect incoming light away from the Earth and to reflect heat energy back toward the Earth's surface. They find that the amount of incident light energy and surface temperature decreases as the sky becomes cloudier. These results will inform longer-term studies that may compare against the amount of energy clouds reflect back toward the Earth.

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A Simple Printing Solution to Aid Deficit Reduction

Mirchandani et al. | Mar 09, 2014

A Simple Printing Solution to Aid Deficit Reduction

The printing-related expenditure that is budgeted in 2014 for U.S. Federal agencies is $1.8 billion. A sample of five publically available documents produced by various federal agencies is analyzed and the cost savings arising from a change in font type are estimated. The analysis predicts that the Government’s annual savings by switching to Garamond are likely to be about $234 million with worst-case savings of $62 million and best-case savings of $394 million. Indirect benefits arising from a less detrimental impact on the environment due to lower ink production and disposal volumes are not included in these estimates. Times New Roman is not as efficient as Garamond, and the third federally-recommended font, Century Gothic, is actually worse on average than the fonts used in the sample documents.

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The Development and Maximization of a Novel Photosynthetic Microbial Fuel Cell Using Rhodospirillum rubrum

Gomez et al. | Mar 02, 2014

The Development and Maximization of a Novel Photosynthetic Microbial Fuel Cell Using <em>Rhodospirillum rubrum</em>

Microbial fuel cells (MFCs) are bio-electrochemical systems that utilize bacteria and are promising forms of alternative energy. Similar to chemical fuel cells, MFCs employ both an anode (accepts electrons) and a cathode (donates electrons), but in these devices the live bacteria donate the electrons necessary for current. In this study, the authors assess the functionality of a photosynthetic MFC that utilizes a purple non-sulfur bacterium. The MFC prototype they constructed was found to function over a range of environmental conditions, suggesting its potential use in industrial models.

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Development of Two New Efficient Means of Wastewater Treatment

Bao et al. | Feb 06, 2014

Development of Two New Efficient Means of Wastewater Treatment

The water we use must be treated and cleaned before we release it back into the environment. Here, the authors investigate two new techniques for purifying dissolved impurities from waste water. Their findings may give rise to more cheaper and more efficient water treatment and help keep the planet greener.

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