Knowledge Update

​Washington, Feb 25 (IANS) Inspired by a desert beetle, cactus and pitcher plant, researchers from Harvard University have designed a new material to collect water droplets from thin air that can one day help fill the drying reservoirs on our planet.

The team from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering drew inspiration from these organisms to develop a better way to promote and transport condensed water droplets.

“Our research shows that a complex bio-inspired approach, in which we marry multiple biological species to come up with non-trivial designs for highly efficient materials with unprecedented properties, is a new, promising direction in biomimetics,” explained Joanna Aizenberg, the Amy Smith Berylson professor of materials science at SEAS.

Organisms such as cacti and desert beetles can survive in arid environments because they have evolved mechanisms to collect water from thin air. 

The Namib desert beetle, for example, collects water droplets on the bumps of its shell while V-shaped cactus spines guide droplets to the plant's body.

The new system, described in the journal Nature, is inspired by the bumpy shell of desert beetles, the asymmetric structure of cactus spines and slippery surfaces of pitcher plants. 

The material harnesses the power of these natural systems, plus Slippery Liquid-Infused Porous Surfaces technology (SLIPS) developed in Aizenberg's lab, to collect and direct the flow of condensed water droplets.

This approach is promising not only for harvesting water but also for industrial heat exchangers.

Thermal power plants, for example, rely on condensers to quickly convert steam to liquid water.

“This design could help speed up that process and even allow for operation at a higher temperature, significantly improving the overall energy efficiency,” added Philseok Kim, vice president of technology at SEAS spin-off SLIPS Technologies, Inc.

The major challenges in harvesting atmospheric water are controlling the size of the droplets, speed in which they form and the direction in which they flow.

“This research is an exciting first step towards developing a passive system that can efficiently collect water and guide it to a reservoir,” Kim noted.​

​New York, Feb 24 (IANS) The world's 33 major deltas are sinking and the vast majority of those have experienced flooding in recent years, primarily as a result of human activity, says a new study.
Some 500 million people live on river deltas around the world, a number that continues to climb as the population increases, the study pointed out.
"These deltas are starved of the sediments they need for stability because of upstream dams that trap the material," said researcher James Syvitski, professor in geological sciences at the University of Colorado Boulder in the US.
"We are seeing coastal erosion increasing in many places across the planet," Syvitski noted.
Human effects on river deltas range from engineering tributaries and river channels, extracting groundwater and fossil fuels, trapping sediments behind dams, reducing peak flows of rivers and varied agricultural practices, he said.The findings were presented at the 2016 Ocean Sciences meeting held in New Orleans, US.River deltas are land areas created by sediment that collects at the mouths of rivers as they enter slow moving or standing water like oceans and estuaries. 
"Deltas are sinking at a much greater rate than sea levels are rising," Syvitski said.
The findings are based on international Community Surface Dynamics Modeling System (CSDMS) - global, interdisciplinary programme involving hundreds of researchers and students in 500 institutes in 68 countries.
For the study, the researchers looked into the degradation of major river deltas in the world, from Yellow River in China to the Mississippi River in Louisiana, US.The two major river deltas in the United States are the Mississippi River Delta in Louisiana and the Sacramento-San Joaquin River Delta in California. 
While the Sacramento-Joaquin Delta has significant issues with agricultural, industrial and urban pollution and subsidence, things are more dire in the Mississippi River Delta, where a football field-sized chunk of wetlands disappears every hour, Syvitski said. 
There are more than 40,000 dams 20 feet or higher on the Mississippi River system, he noted.​

​California, April 6 (IANS) Social media giant Facebook on Wednesday launched 'Facebook Live' -- a feature that enables users to interact with their friends and users real-time through live videos.