Researchers combine an iPhone with optical filters to create a handheld analyzer for toxins, bacteria and other items of public health importance.
A virtual cottage industry has emerged around finding innovative uses for smartphones, well beyond basic calling, texting and Internet access. In particular, there’s been a lot of interest in turning iPhones into something like the <i>Star Trek</i> medical tricorder.
For example, University of Illinois researchers are developing an app and cradle-like device that makes the iPhone a biosensor. The key is the smartphone’s camera and processing power combined with the lenses and filters located in the cradle.
Just put a sample of what you want to study on a slide and insert it into the cradle. The iPhone screen indicates a shift in wavelength when the cradle’s photonic crystal detects toxins, proteins, bacteria, viruses or other biological materials on the slide. The researchers published in the journal Lab on a Chip. [Dustin Gallegos et al., Label-free biodetection using a smartphone]
Imagine using a smartphone to tell if there are toxins in harvested corn and soybeans or pathogens in a water supply. That’s a handy tool that lowers the cost of medical fieldwork. Plus, when you’re done, it’s easy to call in the results.
E-waste is a growing toxic nightmare. And it’s not just a problem in developing countries.
AMERICANS replace their cellphones every 22 months, junking some 150 million old phones in 2010 alone. Ever wondered what happens to all these old phones? The answer isn’t pretty.
In far-flung, mostly impoverished places like Agbogbloshie, Ghana; Delhi, India; and Guiyu, China, children pile e-waste into giant mountains and burn it so they can extract the metals — copper wires, gold and silver threads — inside, which they sell to recycling merchants for only a few dollars. In India, young boys smash computer batteries with mallets to recover cadmium, toxic flecks of which cover their hands and feet as they work. Women spend their days bent over baths of hot lead, “cooking” circuit boards so they can remove slivers of gold inside. Greenpeace, the Basel Action Network and others have posted YouTube videos of young children inhaling the smoke that rises from burned phone casings as they identify and separate different kinds of plastics for recyclers. It is hard to imagine that good health is a by-product of their unregulated industry.
Indeed, most scientists agree that exposure poses serious health risks, especially to pregnant women and children. The World Health Organization reports that even a low level of exposure to lead, cadmium and mercury (all of which can be found in old phones) can cause irreversible neurological damage and threaten the development of a child.
(Credit: iStockphoto) Another innovative feature has been added to the world’s first practical “artificial leaf,” making the device even more suitable-
Another innovative feature has been added to the world’s first practical “artificial leaf,” making the device even more suitable for providing people in developing countries and remote areas with electricity, scientists reported here today.
It gives the leaf the ability to self-heal damage that occurs during production of energy.
Daniel G. Nocera, Ph.D., described the advance during the “Kavli Foundation Innovations in Chemistry Lecture” at the 245th National Meeting & Exposition of the American Chemical Society.
Nocera explained that the “leaf” — a catalyst-coated wafer of silicon — mimics the ability of real leaves to produce energy from sunlight and water. Dropped into a jar of water and exposed to sunlight, catalysts in the device break water down into hydrogen and oxygen. Those gases bubble up and can be collected and used as fuel to produce electricity in fuel cells.
“Surprisingly, some of the catalysts we’ve developed for use in the artificial leaf device actually heal themselves,” Nocera said. “They are a kind of ‘living catalyst.’ This is an important innovation that eases one of the concerns about initial use of the leaf in developing countries and other remote areas.”
Nocera, who is the Patterson Rockwood Professor of Energy at Harvard University, explained that the artificial leaf likely would find its first uses in providing “personalized” electricity to individual homes in areas that lack traditional electric power generating stations and electric transmission lines.
Less than one quart of drinking water, for instance, would be enough to provide about 100 watts of electricity 24 hours a day. Earlier versions of the leaf required pure water, because bacteria eventually formed biofilms on the leaf’s surface, shutting down production.
However, the new self-healing featire “enables the artificial leaf to run on the impure, bacteria-contaminated water found in nature,” Nocera said. “We figured out a way to tweak the conditions so that part of the catalyst falls apart, denying bacteria the smooth surface needed to form a biofilm. Then the catalyst can heal and re-assemble.”
More people in India have access to cellphones than to basic sanitation. Meanwhile, more than 7,000 villages in the northwestern part of the country suffer drinking water shortages as the water table in this breadbasket region continues to drop. And the same story can be told all over the world, according to participants of a water conference at Columbia University on March 28.
This may be the “Blue Marble” with 70 percent of the planet’s surface covered in watery oceans, but the abundance is primarily made up of saltwater. Freshwater that’s clean enough for people to drink and plentiful enough to grow crops and other vital human activities is in increasingly short supply.
In the U.S., agriculture, industry and people combine to use more water than flows in the nation’s rivers. The difference is pulled up from beneath surface of the earth. “We depend on ground water, it’s going away,” noted economist Jeff Sachs, director of the Earth Institute, which convened the State of the Planet: Water conference. “This is a new geologic era where humanity has taken over key [planetary] drivers: the water cycle, carbon cycle, nitrogen cycle.”
The obvious solution, at least to economists, is: if water has become a scarce good then it needs an appropriate price to properly allocate it. Water engineer John Briscoe of Harvard University noted that Australian farmers survived the recent crippling drought—which resulted in a 70 percent reduction in water flow in the Murray-Darling river basin—because of a water trading system that shifted water use from low-value, high-water use crops like rice to cities that needed the H2O more. “This is Econ 101 at work,” he said.
Rivers pay no mind to political boundaries. If unimpeded by dams and diversions, they flow naturally from mountain headwaters to the sea, crossing borders both within and between countries as if political maps did not exist.
f the world is to meet growing food, energy, and consumer demands over the coming years while sustaining the ecosystems that support life on the planet, we will need to think more like watersheds and less like states or nations. Only in this way can we get more benefit out of every drop of Earth’s finite water.
As a river flows toward the sea, it can generate hydroelectric power in its upper reaches, irrigate crops in the valleys, supply drinking water to cities and towns, and sustain recreation and fisheries from headwaters to the coastal zones. But we can only optimize the benefits that rivers provide if we work together – and across borders – to secure and share them.
This is not easy to do. It requires both a new mindset about water and a quantum leap in cooperation, the theme of this year’s World Water Day.
Worldwide there are now 276 river basins encompassing two or more countries. Europe’s Danube is shared by eighteen nations, Africa’s Nile by eleven, Asia’s Indus by five, and North America’s Colorado by two.
Rarely are there treaties that set out how the flows of these international rivers should be shared by all the parties in the basin. A 1959 treaty between Egypt and Sudan, for example, divvies up the entire flow of the Nile, but doesn’t allot any water to the other basin countries – including Ethiopia, which contributes 84 percent of the Nile’s total flow. Far from solving water disputes, such a treaty can fuel them.
The discovery that sea urchins use Nickel particles to harness carbon dioxide from the sea could be the key to capturing tons of CO2 from the atmosphere.
Experts at Newcastle University, UK, have discovered that in the presence of a Nickel catalyst, CO2can be converted rapidly and cheaply into the harmless, solid mineral, calcium carbonate.
This discovery, which is published February 5 in the academic journal Catalysis Science & Technology, has the potential to revolutionize the way we capture and store carbon enabling us to significantly reduce CO2 emissions -- the key greenhouse gas responsible for climate change.
Dr Lidija Šiller, a physicist and Reader in Nanoscale Technology at Newcastle University, says the discovery was made completely by chance.
"We had set out to understand in detail the carbonic acid reaction -- which is what happens when CO2 reacts with water -- and needed a catalyst to speed up the process," she explains.
"At the same time, I was looking at how organisms absorb CO2 into their skeletons and in particular the sea urchin which converts the CO2 to calcium carbonate.
3D printers are getting cooler every day, but there’s one component integral to 3D printing that normally gets overlooked – that is, until you have to pay for it.
As many 3D hobbyists have no doubt discovered, the one time cost of the printer can be quickly dwarfed by feeding it spool after spool of raw plastic. At $40 or more per spool, an avid hobbyist can see his or her enthusiasm rapidly diminished.
Maybe Filabot won’t revolutionize how 3D printing is done, but how often it is done.
Filabot is a 3D plastic extrusion system that takes all kinds of recyclable plastic – milk jugs, soda, detergent and shampoo bottles – and turns them into raw material for 3D printing creativity. Launched as a Kickstarter campaign, Filabot raised three times its $10,000 goal. Its creator, Tyler McNaney, plans on launching in the near future.
Not only will your household recyclables now appear as treasure troves of cheap and virtually endless supply of 3D printing plastic, all those projects that didn’t print right, cracked, or just didn’t turn out the way you thought it would can now be given a second chance at greatness.
The way Filabot works is pretty straightforward. It’s fed pieces of plastic up to 4 inches in diameter, which are then ground down to smaller pieces and are squeezed through a heated barrel that melts the plastic down. The molten plastic is then extruded out through interchangeable nozzles – 3mm or 1.75mm in diameter – to produce the plastic filament. The filament is then shaped to the right size for printing as it is pressed between a pair of grooved barrels. Finally, a cutter corrects any shape irregularities that might’ve made it past the barrels.
There is a certain curiosity about the way water is used in Phoenix, which gets barely eight inches of rain a year but is not necessarily parched.
The hiss of sprinklers serenades improbably green neighborhoods early in the morning and late at night, the moisture guarding against the oppressive heat. This is the time of year when temperatures soar, water consumption spikes and water bills skyrocket in this city, particularly for those whose idea of desert living includes cultivating a healthy expanse of grass.
Half of the water consumed in homes here is used to irrigate lawns, but there is a certain curiosity about the way water is used in Phoenix, which gets barely eight inches of rain a year but is not necessarily parched.
The per capita consumption here, 108 gallons a day, is less than in Los Angeles, where residents average 123 gallons a day. And though humid Southeastern cities like Atlanta have grappled with recurrent water shortages, there is no limit here to how many times someone can wash a car or water flowers in a yard.
“We’re often maligned as being an unsustainable place simply for existing in an arid climate,” said Colin Tetreault, senior policy adviser for sustainability for Mayor Greg Stanton. “But that’s just myopic.”
Experts call on governments to start conserving water in face of climate change, pollution and over-use
The majority of the 9 billion people on Earth will live with severe pressure on fresh water within the space of two generations as climate change, pollution and over-use of resources take their toll, 500 scientists have warned.
The world's water systems would soon reach a tipping point that "could trigger irreversible change with potentially catastrophic consequences", more than 500 water experts warned on Friday as they called on governments to start conserving the vital resource. They said it was wrong to see fresh water as an endlessly renewable resource because, in many cases, people are pumping out water from underground sources at such a rate that it will not be restored within several lifetimes.
"These are self-inflicted wounds," said Charles Vörösmarty, a professor at the Cooperative Remote Sensing Science and Technology Centre. "We have discovered tipping points in the system. Already, there are 1 billion people relying on ground water supplies that are simply not there as renewable water supplies."
A majority of the population – about 4.5 billion people globally – already live within 50km of an "impaired" water resource – one that is running dry, or polluted. If these trends continue, millions more will see the water on which they depend running out or so filthy that it no longer supports life.
Technology allows us to achieve great things – so many goods are made affordable, for example, by mass production. But when mass production is not responsibly planned out and regulated, trash starts piling up.
Oslo, where roughly half the city and most of its schools are heated by burning garbage, is forced to import garbage to supply its waste-to-energy incinerating plants.
This is a city that imports garbage. Some comes from England, some from Ireland. Some is from neighboring Sweden. It even has designs on the American market.
“I’d like to take some from the United States,” said Pal Mikkelsen, in his office at a huge plant on the edge of town that turns garbage into heat and electricity. “Sea transport is cheap.”
Oslo, a recycling-friendly place where roughly half the city and most of its schools are heated by burning garbage — household trash, industrial waste, even toxic and dangerous waste from hospitals and drug arrests — has a problem: it has literally run out of garbage to burn.
The problem is not unique to Oslo, a city of 1.4 million people. Across Northern Europe, where the practice of burning garbage to generate heat and electricity has exploded in recent decades, demand for trash far outstrips supply. “Northern Europe has a huge generating capacity,” said Mr. Mikkelsen, 50, a mechanical engineer who for the last year has been the managing director of Oslo’s waste-to-energy agency.
Yet the fastidious population of Northern Europe produces only about 150 million tons of waste a year, he said, far too little to supply incinerating plants that can handle more than 700 million tons. “And the Swedes continue to build” more plants, he said, a look of exasperation on his face, “as do Austria and Germany.”
A hybrid farmland grass, developed by a team of UK researchers, could help reduce flooding by cutting the volume of run-off reaching rivers, a study suggests.
A team of plant and soil scientists said tests showed the new cultivar reduced run-off by 51%, compared with a variety widely used to feed livestock.
They added that rapid growth and well developed root systems meant that more moisture was retained within the soil rather than running into river systems.
The findings appear in the journal Scientific Reports.
The novel grass is a hybrid of perennial ryegrass (Lollium perenne) - which is widely planted by farmers for grazing livestock - and meadow fescue (Festuca pratensis), which has environmental stress-resistant characteristics.
GEORGIA TECH / PURDUE (US) — Fabricating new plant-based solar cells on cellulose nanocrystal substrates means that they’re recyclable in water.
The researchers report that the organic solar cells reach a power conversion efficiency of 2.7 percent, an unprecedented figure for cells on substrates derived from renewable raw materials.
The cellulose nanocrystal (CNC) substrates on which the solar cells are fabricated are optically transparent, which lets light pass through them before being absorbed by a very thin layer of an organic semiconductor.
During the recycling process, the solar cells are simply immersed in water at room temperature. Within minutes, the CNC substrate dissolves and the solar cell can be separated easily into its major components.
Professor Bernard Kippelen of Georgia Institute of Technology’s College of Engineering led the study and says his team’s project opens the door for a truly recyclable, sustainable, and renewable solar cell technology.
“The development and performance of organic substrates in solar technology continues to improve, providing engineers with a good indication of future applications,” says Kippelen, who is also the director of Georgia Tech’s Center for Organic Photonics and Electronics (COPE).
“But organic solar cells must be recyclable. Otherwise we are simply solving one problem, less dependence on fossil fuels, while creating another, a technology that produces energy from renewable sources but is not disposable at the end of its lifecycle.”
The 2009 Austin City Limits Music Festival stank. It wasn’t the bands that were the problem.
It wasn’t the bands that were the problem. Earlier that year, Austin had laid sod in Zilker Park, home of the annual fall festival, after years of dust problems, including one gritty festival infamously known as the “dust bowl.” In keeping with the city’s environmentally friendly ways, Austin used a locally made compost called Dillo Dirt when laying the new grass. But a day of heavy rain and tens of thousands of festivalgoers turned Zilker’s lush lawn into a mud pit. Dads toting Texas-orange camping chairs, hipsters decked out in impractical vintage, and college students in bikinis and rain boots all shared the same traumatized, confused expression as they waded into the chocolate-pudding-like sludge: What is that smell? The park was ripe with the scent of human waste.
The culprit? The Dillo Dirt, a compost whose central component is highly treated human waste, known in waste-management circles as biosolids. In cities across the United States, biosolids are being used to achieve greater civic efficiency while reducing costs. But concerns over regulation and health effects and a general uneasiness with our bowel movements—sterilized or not—are providing fodder for punny poop headlines in newspapers large and small.
Humans have been using their own waste as fertilizer for eons, but many Americans remain squeamish about taking the trend to a Portlandia level of green dedication. Nowadays, when you flush the toilet, your waste flows through a multipart system that ultimately discharges treated water into waterways and has standards for how to deal with the leftovers, known as sewage sludge. Until the mid-20th century, cities often dumped raw or partially treated waste directly into nearby rivers, lakes, or oceans. (The 1972 Clean Water Act eliminated most freshwater dumping, but ocean dumping wasn’t outlawed until 1988.) Cities then faced the dilemma of what to do with the 7.18 million tons of sewage sludge produced annually in the United States.
U. VIRGINIA (US) — A ceramic tablet infused with silver or copper nanoparticles can disinfect water for up to six months.
Called MadiDrop, the tablets are being developed for use in communities in South Africa that have little to no access to water.
PureMadi, a nonprofit University of Virginia organization, invented the tablet and has established a water filter factory in Limpopo province, South Africa, employing local workers. The factory has produced several hundred flowerpot-like water filters that utilize the same technology as the tablets to purify water.
Mark Tran: Costa Rican academics are pioneering the growth of crops on freshwater lakes as a way of addressing food shortages
Hunger and nutrition will feature prominently at the G8 summit in Northern Ireland in June, in keeping with the renewed interest in agriculture, especially in Africa, where investors are eyeing the potential of vast tracts of land.
But as experts note, water is the most severe impediment to increasing food production and security.