Researchers Fabricate Rewritable Paper

Chemists at the University of California, Riverside have fabricated novel rewritable paper, one that is based on the color-switching property of commercial chemicals called redox dyes.  The dye forms the imaging layer of the paper. Printing is achieved by using ultraviolet light to photobleach the dye, except the portions that constitute the text on the paper. The new rewritable paper can be erased and written on more than 20 times, with no significant loss in contrast or resolution.“This rewritable paper does not require additional inks for printing, making it both economically and environmentally viable,” said Yadong Yin, a professor of chemistry, whose lab led the research. “It represents an attractive alternative to regular paper in meeting the increasing global needs for sustainability and environmental conservation.”SourceAlso: Learn about Biodegradable MEMS Based on Cellulose Paper.

Posted in: News


New Coating Cools Buildings, Beams Away Heat

Stanford engineers have invented a revolutionary coating material that can help cool buildings, even on sunny days, by radiating heat away from the buildings and sending it directly into space.

Posted in: News, Energy Efficiency, Coatings & Adhesives


NASA's Hot 100 Technologies: Environment

Contaminated Water Treatment This method offers a way of processing and recycling liquids to remove contaminants. The two-step process provides a contaminant treatment pouch, called a “urine cell” or “contaminant cell,” that converts urine or another liquid containing contaminants into a fortified drink, engineered to meet human hydration, electrolyte, and caloric requirements.

Posted in: Articles, Techs for License


NASA Computer Model Reveals Carbon Dioxide Levels

An ultra-high-resolution NASA computer model has given scientists a stunning new look at how carbon dioxide in the atmosphere travels around the globe.Plumes of carbon dioxide in the simulation swirl and shift as winds disperse the greenhouse gas away from its sources. The simulation also illustrates differences in carbon dioxide levels in the northern and southern hemispheres, and distinct swings in global carbon dioxide concentrations as the growth cycle of plants and trees changes with the seasons.Scientists have made ground-based measurements of carbon dioxide for decades and in July NASA launched the Orbiting Carbon Observatory-2 (OCO-2) satellite to make global, space-based carbon observations. But the simulation — the product of a new computer model that is among the highest-resolution ever created — is the first to show in such fine detail how carbon dioxide actually moves through the atmosphere.In addition to providing a striking visual description of the movements of an invisible gas like carbon dioxide, as it is blown by the winds, this kind of high-resolution simulation will help scientists better project future climate. Engineers can also use this model to test new satellite instrument concepts to gauge their usefulness. The model allows engineers to build and operate a “virtual” instrument inside a computer.SourceAlso: Learn about the NASA Data Acquisition System (NDAS).

Posted in: News, Environmental Monitoring, Greenhouse Gases, Measuring Instruments


Ocean Gliders Measure Melting Polar Ice

The rapidly melting ice sheets on the coast of West Antarctica are a potentially major contributor to rising ocean levels worldwide. Although warm water near the coast is thought to be the main factor causing the ice to melt, the process by which this water ends up near the cold continent is not well understood. Using robotic ocean gliders, Caltech researchers have now found that swirling ocean eddies, similar to atmospheric storms, play an important role in transporting these warm waters to the Antarctic coast—a discovery that will help the scientific community determine how rapidly the ice is melting and, as a result, how quickly ocean levels will rise. "When you have a melting slab of ice, it can either melt from above because the atmosphere is getting warmer or it can melt from below because the ocean is warm," explains lead author Andrew Thompson, assistant professor of environmental science and engineering. "All of our evidence points to ocean warming as the most important factor affecting these ice shelves, so we wanted to understand the physics of how the heat gets there." Because the gliders are small—only about six feet long—and are very energy efficient, they can sample the ocean for much longer periods than large ships can. When the glider surfaces every few hours, it "calls" the researchers via a mobile phone–like device located on the tail. The communication allows the researchers to almost immediately access the information the glider has collected. Like airborne gliders, the bullet-shaped ocean gliders have no propeller; instead they use batteries to power a pump that changes the glider's buoyancy. When the pump pushes fluid into a compartment inside the glider, the glider becomes denser than seawater and less buoyant, thus causing it to sink. If the fluid is pumped instead into a bladder on the outside of the glider, the glider becomes less dense than seawater—and therefore more buoyant—ultimately rising to the surface. Like airborne gliders, wings convert this vertical lift into horizontal motion. Source Also: Learn about Remote Sensing of Ice Sheets and Snow.

Posted in: News, Batteries, Environmental Monitoring, Machinery & Automation, Robotics, Measuring Instruments, Monitoring


Space-Based Instrument Monitors Plant Health

A new space‑based instrument to study how effectively plants use water is being developed at NASA's Jet Propulsion Laboratory. The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) will monitor one of the most basic processes in living plants: the loss of water through the tiny pores in leaves, or transpiration. ECOSTRESS will measure combined evaporation and transpiration, known as evapotranspiration, from the International Space Station.

Posted in: News, Environmental Monitoring, Greenhouse Gases, Monitoring


New Computer Codes Enable Design of Greener, Leaner Aircraft

A computer model that accurately predicts how composite materials behave when damaged will make it easier to design lighter, more fuel-efficient aircraft. Innovative computer codes form the basis of a computer model that shows in unprecedented detail how an aircraft's composite wing, for instance, would behave if it suffered small-scale damage, such as a bird strike. Any tiny cracks that spread through the composite material can be predicted using this model. 

Posted in: News, Aviation, Greenhouse Gases, Composites