Clog-free print nozzle mimics human eye
COLUMBIA, Mo., July 16 (UPI) -- U.S. researchers say they've looked to the human eye for inspiration in designing a clog-free ink jet printer cartridge.
University of Missouri engineers addressing the problem of clogged printer nozzles that waste time and money while reducing print quality have invented a new nozzle cover, a university release reported Monday.
"The nozzle cover we invented was inspired by the human eye," engineering Professor Jae Wan Kwon, said. "The eye and an ink jet nozzle have a common problem: they must not be allowed to dry while, simultaneously, they must open. We used biomimicry, the imitation of nature, to solve human problems."
Kwon's solution uses a droplet of silicone oil to cover the opening of the nozzle when not in use, similar to the film of oil that keeps a thin layer of tears from evaporating from the eye.
In the human eye, eyelids spread the film of oil over the layer of tears during blinking. However, at the tiny scale of the ink jet nozzle, mechanical shutters "blinking" like eyelids would not work, as they would be stuck in place by surface tension.
Instead, the droplet of oil for the nozzle is moved in and out of place by an electric field, the researchers said.
In most ink jet printers, a burst of fresh ink must break through the crust of dried ink that forms if the machine isn't used regularly. This cleaning operation can waste a large amount of expensive ink over time, a waste Kwon's invention eliminates, the release said.
Apple's next OS may be released July 25
CUPERTINO, Calif., July 16 (UPI) -- Apple's next version of its operating system, dubbed Mountain Lion, may be available to Mac computer users July 25, the 9 to 5 Mac Web site reported.
Although Apple has announced details and features of the upcoming OS, it has yet to announce an official release date.
9 to 5 Mac is saying Apple has asked some of its retail employees to prepare for overnight work on July 24, leading to speculation the new operating system will be available the next day.
The Web site acknowledged the release won't have much to do with Apple's retail stores since Mountain Lion will be distributed via download from the Mac App Store, but speculated the overnight work will see Apple store employees installing the new OS on every Mac computer in the stores.
Mountain Lion, which furthers the design and functional ties between Apple's mobile iOS system and its Mac system, will cost $19.99.
The OS is finished and already distributed in Golden Master form to developers, 9 to 5 Mac said.
Poison from illegal pot farms said a risk
DAVIS, Calif., July 16 (UPI) -- Rat poison used by people illegally growing marijuana in remote areas of California may be killing the fisher, a rare weasel-like carnivore, researchers say.
Researchers from the University of California, Davis, along with the Wildlife Conservation Society and other partner institutions, said they've found commercial rodenticide in dead fishers in Humboldt County near Redwood National Park and in the southern Sierra Nevada in and around Yosemite National Park.
Illegal marijuana farms in remote areas where fishers live are considered a likely source as some marijuana growers apply the poisons to keep a wide range of animals away from their crops.
Fishers are likely exposed to the poison when eating animals that have already ingested it, the conservation society said in a release Monday.
Fishers in California, Oregon and Washington have been declared a candidate for listing under the federal Endangered Species Act.
Other species, including martens, spotted owls and Sierra Nevada red foxes may also be at risk from poisons, researchers said.
"If fishers are at risk, these other species are most likely at risk because they share the same prey and the same habitat," UC Davis researcher Mourad Gabriel said in a university release.
Global warming affecting world's lakes
ZURICH, Switzerland, July 16 (UPI) -- Global warming, a concern for its effects on the world's oceans, is also causing harm to the globe's freshwater lakes, researchers in Switzerland say.
Researchers from the University of Zurich said a study of Lake Zurich showed that because of global warming, there is insufficient water turnover in the lake following the winter and harmful algae known as Burgundy blood algae are increasingly thriving.
Many large lakes in Central Europe became heavily overfertilized in the 20th century through sewage, and as a result algal blooms form, reducing oxygen content in the water and threatening fish stocks, they said.
"The problem today is that mankind is changing two sensitive lake properties at the same time, namely the nutrient ratios and, with global warming, water temperature," Zurich researcher Thomas Posch said.
Historical data on Lake Zurich reveals the cyanobacteria Planktothrix rubescens, more commonly known as Burgundy blood algae, has developed increasingly denser blooms in the last 40 years.
The most important natural control of the cyanobacteria blooms occurs in the spring after the entire lake has cooled down during the winter, as intensive winds trigger the turnover of the surface and deep water.
But with global warming the winters are increasingly too warm and the lake water is not able to turn over fully as the temperature difference between the surface and depths poses a physical barrier, the researchers said.
"Unfortunately, we are currently experiencing a paradox," Posch said. "Even though we thought we had partly solved the nutrient problem, in some lakes global warming works against the clean-up measures.
"Therefore, we primarily need cold winters with strong winds again."
