Maple seed inspires micro helicopters

In a new research, scientists have described the aerodynamic secret of twirling seeds of maple trees, which might have implications for the design of swirling parachutes and micro-helicopters.

The research, led by David Lentink, Wageningen University, Netherlands, and Michael H Dickinson, California Institute of Technology, US, revealed that, by swirling, maple seeds generate a tornado-like vortex that sits atop the front leading edge of the seed as they spin slowly to the ground.

This leading-edge vortex lowers the air pressure over the upper surface of the maple seed, effectively sucking the wing upward to oppose gravity, giving it a boost.

The vortex doubles the lift generated by the seeds compared to nonswirling seeds.

This use of a leading-edge vortex to increase lift is remarkably similar to the trick employed by insects, bats, and hummingbirds when they sweep their wings back and forth to hover. The research might have implications for the design of swirling parachutes and of micro-helicopters.

Electronic glue for semiconductors

Scientists at the University of Chicago and Lawrence Berkeley National Laboratory have developed an ‘electronic glue’ that promises development of less expensive semiconductors.

The electronic glue could accelerate advances in semiconductor-based technologies, including solar cells and thermoelectric devices that convert sun light and waste heat, respectively, into useful electrical energy.

Semiconductors have served as choice materials for many electronic and optical devices because of their physical properties. Commercial solar cells, computer chips and other semiconductor technologies typically use large semiconductor crystals.

But, that is expensive and can make large-scale applications such as rooftop solar-energy collectors prohibitive.

Reindeer decline by 60 per cent

An analysis has revealed that caribou and reindeer numbers worldwide have plunged almost 60 per cent in the last three decades.

The dramatic revelation came out of the first ever comprehensive census analysis of this iconic species carried out by biologists at the University of Alberta in Canada.
According to co-author Liv Vors, global warming and industrial development are responsible for driving this dramatic decline in species numbers around the world.
Vors said that the decline raises serious concerns not only for the animals, but also for people living in northern latitudes who depend on the animals for their livelihood.

Stress turns your hair gray

You must have heard many times from people that stress causes gray hairs. Now, new research suggests it’s true.

According to a new report in the June 12 issue of ‘Cell’, a Cell Press publication, those pesky graying hairs are signs of stress.

Researchers have discovered that the kind of ‘genotoxic stress’ that does damage to DNA depletes the melanocyte stem cells (MSCs) within hair follicles that are responsible for making those pigment-producing cells. Rather than dying off, when the going gets tough, those precious stem cells differentiate, forming fully mature melanocytes themselves. Anything that can limit the stress might stop the graying from happening, the researchers said.

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