The eastern Sahara Desert was once home to a 45,000 km2 freshwater lake similar in surface area to the largest in the world today.
A study led by the University of Exeter has revealed that the mega lake was probably formed more than one hundred thousand years ago in the White Nile River Valley in Sudan.
Dr Tim Barrows of the University of Exeter and colleagues used a dating approach based on exposure to cosmic rays to measure the amount of the isotope beryllium-10 in shoreline deposits. Its abundance can be used to calculate how long rocks or sediments have been exposed at the surface of the earth. (more…)
Researchers from North Carolina State University have created flower-like structures out of germanium sulfide (GeS) – a semiconductor material – that have extremely thin petals with an enormous surface area. The GeS flower holds promise for next-generation energy storage devices and solar cells.
“Creating these GeS nanoflowers is exciting because it gives us a huge surface area in a small amount of space,” says Dr. Linyou Cao, an assistant professor of materials science and engineering at NC State and co-author of a paper on the research. “This could significantly increase the capacity of lithium-ion batteries, for instance, since the thinner structure with larger surface area can hold more lithium ions. By the same token, this GeS flower structure could lead to increased capacity for supercapacitors, which are also used for energy storage.” (more…)
Electrochemical capacitors (ECs), also known as supercapacitors or ultracapacitors, differ from regular capacitors that you would find in your TV or computer in that they store substantially higher amounts of charges. They have garnered attention as energy storage devices as they charge and discharge faster than batteries, yet they are still limited by low energy densities, only a fraction of the energy density of batteries. An EC that combines the power performance of capacitors with the high energy density of batteries would represent a significant advance in energy storage technology. This requires new electrodes that not only maintain high conductivity but also provide higher and more accessible surface area than conventional ECs that use activated carbon electrodes.
Now researchers at UCLA have used a standard LightScribe DVD optical drive to produce such electrodes. The electrodes are composed of an expanded network of graphene — a one-atom-thick layer of graphitic carbon — that shows excellent mechanical and electrical properties as well as exceptionally high surface area. (more…)
COLUMBUS, Ohio – Water-associated infectious disease outbreaks are more likely to occur in areas where a region’s population density is growing, according to a new global analysis of economic and environmental conditions that influence the risk for these outbreaks.
Ohio State University scientists constructed a massive database containing information about 1,428 water-associated disease outbreaks that were reported between 1991 and 2008 around the world. By combining outbreak records with data on a variety of socio-environmental factors known about the affected regions, the researchers developed a model that can be used to predict risks for water-associated disease outbreaks anywhere in the world. (more…)
