Saturday, April 16, 2011

Solar power without solar cells: A hidden magnetic effect of light could make it possible | Chemistry, Physics and Material Sciences Research

Solar power without solar cells: A hidden magnetic effect of light could make it possible | Chemistry, Physics and Material Sciences Research: "Solar power without solar cells: A hidden magnetic effect of light could make it possible

A dramatic and surprising magnetic effect of light discovered by University of Michigan researchers could lead to solar power without traditional semiconductor-based solar cells.

The researchers found a way to make an “optical battery,” said Stephen Rand, a professor in the departments of Electrical Engineering and Computer Science, Physics and Applied Physics.

In the process, they overturned a century-old tenet of physics.

“You could stare at the equations of motion all day and you will not see this possibility. We’ve all been taught that this doesn’t happen,” said Rand, an author of a paper on the work published in the Journal of Applied Physics. “It’s a very odd interaction. That’s why it’s been overlooked for more than 100 years.”

Light has electric and magnetic components. Until now, scientists thought the effects of the magnetic field were so weak that they could be ignored. What Rand and his colleagues found is that at the right intensity, when light is traveling through a material that does not conduct electricity, the light field can generate magnetic effects that are 100 million times stronger than previously expected. Under these circumstances, the magnetic effects develop strength equivalent to a strong electric effect.

“This could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation,” Rand said. “In solar cells, the light goes into a material, gets absorbed and creates heat. Here, we expect to have a very low heat load. Instead of the light being absorbed, energy is stored in the magnetic moment. Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power source.”

What makes this possible is a previously undetected brand of “optical rectification,” says William Fisher, a doctoral student in applied physics. In traditional optical rectification, light’s electric field causes a charge separation, or a pulling apart of the positive and negative charges in a material. This sets up a voltage, similar to that in a battery. This electric effect had previously been detected only in crystalline materials that possessed a certain symmetry.

Rand and Fisher found that under the right circumstances and in other types of materials, the light’s magnetic field can also create optical rectification.

“It turns out that the magnetic field starts curving the electrons into a C-shape and they move forward a little each time,” Fisher said. “That C-shape of charge motion generates both an electric dipole and a magnetic dipole. If we can set up many of these in a row in a long fiber, we can make a huge voltage and by extracting that voltage, we can use it as a power source.”

The light must be shone through a material that does not conduct electricity, such as glass. And it must be focused to an intensity of 10 million watts per square centimeter. Sunlight isn’t this intense on its own, but new materials are being sought that would work at lower intensities, Fisher said.

“In our most recent paper, we show that incoherent light like sunlight is theoretically almost as effective in producing charge separation as laser light is,” Fisher said.

This new technique could make solar power cheaper, the researchers say. They predict that with improved materials they could achieve 10 percent efficiency in converting solar power to useable energy. That’s equivalent to today’s commercial-grade solar cells.

“To manufacture modern solar cells, you have to do extensive semiconductorprocessing,” Fisher said. “All we would need are lenses to focus the light and a fiber to guide it. Glass works for both. It’s already made in bulk, and it doesn’t require as much processing. Transparent ceramics might be even better.”

In experiments this summer, the researchers will work on harnessing this power with laser light, and then with sunlight.

The paper is titled “Optically-induced charge separation and terahertz emission in unbiased dielectrics.” The university is pursuing patent protection for the intellectual property.


PhysOrg

New engine shakes up auto industry - Technology & science - Innovation - msnbc.com

New engine shakes up auto industry - Technology & science - Innovation - msnbc.com: "New engine sends shock waves through auto industry
Prototype could potentially decrease auto emissions up to 90 percent



Discovery News
An illustration of the Wave Disk Generator.
By Nic Halverson
updated 4/6/2011 5:29:19 PM ET

Despite shifting into higher gear within the consumer's green conscience, hybrid vehicles are still tethered to the gas pump via a fuel-thirsty 100-year-old invention: the internal combustion engine.

However, researchers at Michigan State University have built a prototype gasoline engine that requires no transmission, crankshaft, pistons, valves, fuel compression, cooling systems or fluids. Their so-called Wave Disk Generator could greatly improve the efficiency of gas-electric hybrid automobiles and potentially decrease auto emissions up to 90 percent when compared with conventional combustion engines.

The engine has a rotor that's equipped with wave-like channels that trap and mix oxygen and fuel as the rotor spins. These central inlets are blocked off, building pressure within the chamber, causing a shock wave that ignites the compressed air and fuel to transmit energy.

The Wave Disk Generator uses 60 percent of its fuel for propulsion; standard car engines use just 15 percent. As a result, the generator is 3.5 times more fuel efficient than typical combustion engines.

Researchers estimate the new model could shave almost 1,000 pounds off a car's weight currently taken up by conventional engine systems.

Last week, the prototype was presented to the energy division of the Advanced Research Projects Agency, which is backing the Michigan State University Engine Research Laboratory with $2.5 million in funding.

Michigan State's team of engineers hope to have a car-sized 25-kilowatt version of the prototype ready by the end of the year.

© 2011 Discovery Channel

Tuesday, April 12, 2011

Our Lives Are Under Threat From Some of the Most Powerful and Richest Entities -- Here's How We Can Fight Back and Win | | AlterNet

Our Lives Are Under Threat From Some of the Most Powerful and Richest Entities -- Here's How We Can Fight Back and Win

We need to rebuild the kind of mass movement that marked 1970: bodies, passion, and creativity are the currencies we can compete in. It's not impossible.
Photo Credit: 350.org
Not for forty years has there been such a stretch of bad news for environmentalists in Washington.

Last month in the House, the newly empowered GOP majority voted down a resolution stating simply that global warming was real: they've apparently decided to go with their own versions of physics and chemistry.

This week in the Senate, the biggest environmental groups were reduced to a noble, bare-knuckles fight merely to keep the body from gutting the Clean Air Act, the proudest achievement of the green movement. The outcome is still unclear; even several prominent Democrats are trying to keep the EPA from regulating greenhouse gases.

And at the White House? The president who boasted that his election marked the moment when 'the oceans begin to recede' instead introduced an energy plan heavy on precisely the carbon fuels driving global warming. He focused on 'energy independence,' a theme underscored by his decision to open 750 million tons of Wyoming coal to new mining leases. That's the equivalent of running 3,000 new power plants for a year.

Here's what we think is going on, in the broadest terms.

The modern environmental movement was born on Earth Day 1970, in an unprecedented burst of mass organizing--by some estimates 20 million Americans, a tenth of the population, took to the streets. It was a young movement, at a time when large numbers of people were serious about not just cleaning the air but stopping wars and ending official discrimination. That popular base inspired--or, more likely, cowed--Washington: the next four years saw the passage of virtually all the environmental legislation that still forms the core of green law.

It also saw the birth or rebirth of many of the organizations we think of when we think of environmentalism. Powered by that initial burst of mass support, they were able to make real headway in DC, and so they concentrated on important and professional tasks: patient lobbying of subcommittees, careful report-writing. And they kept making substantial gains: Superfund toxic cleanups, acid-rain control.

But in recent years two things have happened. One, that battery wound up on the first Earth Day has finally wound down: congressmen, it turns out, can tell the difference between an aging membership list and a vibrant political movement. As the DC political bible Politico put it last month: "green groups are being forced to play defense in a world where D.C. pols aren't scared of them."

Second, the key issue has changed. Forget acid rain and Superfund; these were important but relatively easy fights that didn't directly confront anyone's business model. You could clean up acid rain by putting a filter on your power plant. But global warming is different--you'd have to shut down that power plant, and replace it with a windmill or a solar panel.

And so the full power of the fossil fuel industry--the most profitable business in the planet's history--has been brought to bear on the fight, and they play hard and dirty. The Koch Brothers spend huge sums to underwrite the network of global warming skeptics; the US Chamber of Commerce emerged as the biggest campaign funder of them all, shuttling 94% of its donations to climate deniers. This kind of clout carried the day: the biggest dream of DC Washington groups was the so-called 'cap-and-trade' bill, behind which they mustered every insider technique they'd spent the last four decades perfecting. But in the end they didn't come close: Harry Reid refused to even schedule a floor vote, knowing that he was far short of the votes needed to pass the bill. The White House stayed on the sidelines.

To us, the lesson is pretty clear. Since we're never going to have as much money as the fossil fuel industry, we need to rebuild the kind of mass movement that marked 1970: bodies, passion, and creativity are the currencies we can compete in. It's not impossible. Working with next to no money, the fledgling campaign at 350.org managed over the last three years to coordinate 15,000 rallies in 189 countries--every nation on earth save North Korea. It's been active in every US state and Congressional district. And this week, it combined forces with another important American grass roots climate campaign, 1Sky, for extra reach.

1Sky was founded in the same spirit, and at the same time, as 350.org, and has worked to develop leaders around the country and help build a base of hundreds allies. Together, we'll be smarter, bolder, faster, and more creative than we were before.

This new and expanded 350.org will mobilize on a large scale--circle Sept. 24 on your calendar for a worldwide day of bike-based action. But it's also going aggressively after the backroom money, with a far-reaching new campaign that tackles the US Chamber of Commerce for its climate stance.

This youth-based campaign is linking up with labor, with faith communities, with frontline communities who have the most experience trying to shut down dirty power plants in their backyards. Most of all it's actually out in the streets, organizing new blood. The idea is not to supplant the Washington green groups, but instead to give the whole movement new clout--enough clout to withstand the crushing power of oil money. And enough energy to let us get off defense and back on the attack.

We don't know if we'll win in the end: the science of climate change grows darker by the day, and the window for effective action is swiftly closing. But any chance requires people power replacing corporate power. In the year of Tunisia and Egypt and Wisconsin, it's worth a try.

Saturday, April 02, 2011

Can't make white colors become transparent in PowerPoint 2002/XP

Can't make white colors become transparent in PowerPoint 2002/XP:

Can't make white colors become transparent in PowerPoint 2002/XP

Problem

You bring an image into PowerPoint and attempt to use the transparency tool to make the white pixels in the image transparent, but nothing happens. You can make other colors transparent, just not white. It works with the same image in earlier versions of PowerPoint.
Solutions
  • After pasting image into PowerPoint
    1. Cut
    2. Paste Special, As JPEG or PNG
    3. Set Transparent Color now works
  • Instead of Pasting into PowerPoint...
    1. Paste into an image editing program (PhotoEditor, Paint, etc.)
    2. Save as JPEG or PNG
    3. In PowerPoint, Insert -> Picture from file
    4. Set Transparent Color now works