piezoelectric - vibrations

Converting Mechanical Vibrations into Electrical Energy Electrical engineer Rajeevan Amirtharajah and his students at the University of California, Davis, have demonstrated a novel device for harvesting mechanical energy. The device consists of a small disk made of piezoelectric material (material that generates electric potential in response to mechanical stress) scribed with multiple electrodes. External vibrations induce special vibrational shapes, or modes, within the disk, which generate multiple voltages with unique phase relationships. Their research has focused on developing integrated circuits that combine the generated voltages with greater than 98 percent efficiency into a single power supply, effectively harvesting energy from the environment. Previous work in such devices has focused on one-dimensional systems such as cantilever beams; this work has demonstrated improved energy harvesting efficiency by using two-dimensional systems such as disks combined with efficient power conversion electronics. Sensors that harvest energy from their environment transcend the current limitations of traditional battery-powered sensors. Battery-powered wireless sensor networks (such as those used in infrastructure monitoring, health care, national security, and space exploration) are limited in individual sensor size, operating lifetime and maintenance cost by the finite energy capacity of batteries. The combination of new energy harvesting devices, highly efficient energy conversion electronics, and energy scalable integrated circuits offers great promise. If realized, it could extend the operating life of wireless sensors, reduce the maintenance cost and environmental impact of battery replacement, and enable entirely new applications such as long-lived centimeter-scale biomedical implants.

http://news.discovery.com/tech/alternative-power-sources/windpower-without-blades-101015.htm Wind Power Without the Blades OCT 15, 2010 11:51 AM ET // BY ALYSSA DANIGELIS Each stalk will contain alternating layers of electrodes and ceramic discs made from piezoelectric material, which generates a current when put under pressure.

rede de dormir

rede de dormir an invention of south american indians: http://www.redetec.org.br/inventabrasil/redeini.htm

Squid Communication / "Bacterial Illumination"

piezoeletrico http://www.newtoncbraga.com.br/index.php/como-funciona/4571-art632.html

Bright Squid (bacteria) http://www.cbsnews.com/2100-205_162-592194.html

"The light itself is provided by colonies of luminescent bacteria that live on the squids, the researchers report in Friday's issue of the journal Science." http://www.this-magic-sea.com/COMBACTL.HTM

around "Bacterial Illumination"(in http://www.this-magic-sea.com/COMBACTL.HTM) "Squid Communicate with each other using a wide spectrum of colors and postures. At night they signal with luminescent organs. The squid's luminescent communications result from communications between bacteria living in special light organs. Squid, and a variety of fish, have luminescent bacteria housed in special sacs called light organs. The bacteria generate light with an enzyme called luciferase - but not all the time. When the bacteria Vibrio fischeri swim free in sea water, their population densities are very low and they do not produce light. When they inhabit the light organs of squid, however, the squid cells nurture the bacteria and their populations soar to high levels. When the bacteria are packed tight, they begin to secrete messenger proteins called autoinducer. As this reaches a critical level, it enters the bacteria and activates a protein called LuxR. Activated LuxR stimulates the bacterial genes to produce the light producing proteins luciferin, luciferase and associated light producing proteins. The genes are stimulated to produce additional autoinducer messengers and these are released from the bacteria. The additional production of autoinducer messengers, triggered by the active LuxR, stimulate another round of protein synthesis. This positive feedback loop results in rapid production of light producing proteins. When these proteins reach a critical density, they react with each other to liberate that delightfully eerie blue phosphorescence of the sea."

As any squid knows, visual communication is a wonderful way to convey a message. It has a major downside, though; predators can tune in to the broadcast just as readily as the intended recipients (other squid) can. A recent study by Lydia M. Mäthger and Roger T. Hanlon, both biologists at the Marine Biological Laboratory in Woods Hole, Massachusetts, suggests that squid—and most likely their close relatives, cuttlefish and octopuses—have evolved a secret communication channel to which their predators are oblivious. Squid, cuttlefish, and octopuses are known for their ability to change their skin color in a spectacular way. They can blend instantly into the background or produce a startling array of patterns and hues to express their physiological or motivational state. The secret to the show is the two distinct layers of cephalopod skin: The inner layer of iridophore cells is both iridescent and reflects polarized light. The outer layer is made up of pigmented organs, or chromatophores, which expand or contract to help change the color or pattern of the skin. Cuttlefish, octopuses, and squid have a visual system to match the complexity of their skin. Unlike their vertebrate predators, they can detect differences in polarized light. Mäthger and Hanlon discovered that the two skin layers work independently, and that by taking advantage of the reflective properties of the iridophores, squid may be able to communicate with other squid via polarized light. At the same time, the squid can camouflage themselves from predators by altering the color pattern in the chromatophore layer, through which polarized light travels freely. What happens among squid stays among squid!" http://www.tonmo.com/forums/showthread.php?8667-Secret-squid-communication

Make: Projects How-to

http://makeprojects.com/ http://makeprojects.com/Project/Sun-Logger/2275/1#.UM9sNnPjli4

THE FUTURE OF PLAY

A free exhbiition featuring everything from work by world-renowned game designers such as Eric Zimmerman and architect Nathalie Pozzi to hacks on old favourites like Lunar Trails by Seb Lee-Delisle. GAME offers you the chance to get directly involved in the world's most compelling game play.

http://sciencegallery.com/game

Europa Film Treasures

http://www.europafilmtreasures.eu

LE BAQUET DE MESMER What a strange washtub... when Méliès the magician takes himself for Mesmer the doctor, eccentric statues come to life and give us a cabaret worthy of the Moulin rouge! A Mesmerian Experiment Georges MELIES -1904 Národní filmový archiv an interesting archive... Europa Film Treasures