The discovery of the process of making an electric generating nanowire has been put to  reality out from its concept phase when Harvard chemists built a new wire out of photosensitive materials that is hundreds of times smaller than a human hair. The wire not only carries electricity to be used in vanishingly small circuits, but generates power as well.

Charles M. Lieber, the Mark Hyman Jr. Professor of Chemistry, and colleagues created the nanowire out of three different kinds of silicon with different electrical properties. The silicon is wrapped in layers to create the wire. When light falls on the outer material, a process begins due to the interaction of the core with the shell layers, leading to the creation of electrical charges.

The idea of creating nanoscale photovoltaics is not new, Lieber said, but prior efforts used organic compounds in combination with semiconductor nanostructures that had lower efficiency and that degraded under concentrated sunlight. Lieber’s materials have several advantages, he said. The materials are more efficient, converting 3.4 percent of the sunlight into electricity; they can withstand concentrated light without deteriorating, gaining efficiency up to about 5 percent; and they’re as cheap to make as other related nanoscale photovoltaic devices.

“The real [question] is whether there’s a new geometry that will lead to better photovoltaic technology,” Lieber said. “We worked on coaxial geometry.”

The most recent development builds on Lieber’s considerable prior work on nanoscale devices. He has developed sensors with potential bioterrorism applications that can detect a single virus or other particle, nanowire arrays that can detect signals in individual neurons, and a cracker-sized detector for cancer.

A cheap nanoscale power source broadens the potential applications of such nanoscale devices. Though the tiny photovoltaic cells can generate enough electricity to power a similarly tiny circuit, Lieber said they’re not yet efficient enough to have applications on the scale of commercial power generation.

Commercial solar cells, he said, have efficiencies around 20 percent, compared with 3.4 percent for his nano-solar cells. One avenue of future research, Lieber said, will be to explore ways to boost efficiency of the nanowire photovoltaics. If they can reach 10 to 15 percent, he said, their lower cost of production — they can be made from relatively inexpensive materials and don’t require clean rooms to produce — may make them useful in larger-scale applications.

“There’s no physical reason it couldn’t be higher,” Lieber said. “I’m pretty optimistic that we’ll be able to track down the efficiency issue.”

Until then, Lieber sees a future for the nanowire photovoltaics in niche applications, such as multiple distributed sensors or durable, flexible devices, possibly sewn into clothing or worn as a patch.

“It will have to be unique to be an economically viable application, some place where you want durability and flexibility, where if it gets destroyed, people don’t care,” Lieber said.

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One of the most important, amazing and useful discovery of mankind is the discovery of penicillin.

The British scientist Alexander Fleming discovered it accidentally in 1928. It was shortly after the carnage of the First World War when he conducted experiments with bacteria.

One day while going on with his experiment, a tear from his eye fell into the culture plate and later he noticed that a substance in his tear killed the bacteria. He noted the incident, but didn’t know what to do with it. However, some years later, a similar coincidence occurred. Fleming left his laboratory for the holidays, inadvertently leaving a discarded culture plate lying out on his bench. He simply forgot to clean and disinfect the dish. A bit of mold had fallen into the dish containing the bacteria, forming a clear patch. When he returned, he recognized the possibility of what had happened. He decided that the mold had created some kind of chemical antibiotic, which he named penicillin, after the Penicillium mold that produced it. But Fleming could not extract the bacteria-killing substance, so he moved on to other research.

It is important to note that before the discovery of penicillin, infections were as feared as cancer is today. Imagine living in any generation over the past 6,000 years and facing the dangers of infection. For example, if you pricked your finger on a thorn, or a sewing needle, or stepped on a nail, you could be in big trouble. Your glands could swell up and require lancing, or a surgeon might have to amputate your arm or leg to save your life. This was the story of humanity for six thousand years. And infection was possible at any age. Imagine how many hundreds of millions of needless deaths have plagued mankind over the centuries.

The scientific aspects of the discovery of penicillin were left for another scientist to develop a decade later. He was the Australian scientist, Howard Florey, who felt that no one person contained the knowledge and experience to make major discoveries in the field of medicine. He had the foresight to organize a team of specialists at Oxford University in the 1930s. One member of his team, Ernst Chain, found an article about Alexander Fleming’s work while flipping through a medical journal, and this prompted them to begin a careful investigation of the anti-bacterial properties in mold — the stuff Fleming had called “penicillin.”

Individual members of the group concentrated attention on various areas of their fields of expertise, meeting periodically to exchange ideas. Chain worked with Edward Abraham on purifying penicillin. Norman Heatley improvised methods for extracting penicillin, using ether. They grew the cultures of mold in hospital bedpans. The liquid was drained and filtered through parachute silk.

A. D. Gardner and Jena Orr-Ewing studied how penicillin reacted with other organisms. Howard Florey and Margaret Jennings observed the impact of penicillin on animals. Ethel Florey later worked with her husband on clinical trials.

On May 25, 1940, the team performed one of the most important medical experiments in history. They injected eight mice with a lethal dose of streptococci bacteria. Four of the mice were treated with penicillin, while the other four were used as controls. By the next day, the treated mice had recovered and the untreated mice were dead. To say that Florey’s team was excited, is a decided understatement. World War II was raging and soldiers were dying needlessly. As quickly as he could, Florey set about to test the drug on humans.

They knew that they had to find a way to mass-produce the drug before it could be widely used and British companies were unable to help because of the war. If they had patented their formula, the entire team could have become very wealthy. But in those days, Howard Florey felt that it was unethical to patent their medical discovery. He and Norman Heatley decided to take a dangerous flight to the United States in a blacked-out plane across the Atlantic and explain his method to drug companies in the United States.

A Department of Agriculture laboratory just happened to be looking for a new use for a thick liquid — the by-product from a corn-milling process. When this liquid was used to grow mold, they were able to extract ten times the amount of penicillin. Mary Hunt, known as Moldy Mary because of her enthusiasm in finding new sources of mold, discovered that growing mold in cantaloupe was twice again as successful in producing penicillin.

By late 1943, only four years after the first mouse experiment, and in spite of the war, mass production of the drug was underway. By the end of the war, many companies were producing the drug, including Merck, Squibb and Pfizer.

In 1943, Howard Florey took a supply of penicillin to treat wounded troops in North Africa. Instead of amputating wounded limbs, he suggested the wounds be cleaned, sewn up and treated with penicillin. It appeared to be an absolute miracle! For the first time in human history, medical science had been revolutionized. Since that time, untold millions of lives have been saved from otherwise certain death.

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 Ninety miles off Norway’s northern coast, beneath the Arctic Ocean, in one of the world’s least hospitable places, a vast deposit of natural gas was discovered a quarter of a century ago which now has greatly enticed energy executives around the world.

Bitter winds and frequent snowstorms lash the region. The sun disappears for two months a year. No oil company knew how to operate in such a harsh environment.

But Norway has finally solved the problem. The other day, on an island just offshore, a giant yellow flame illuminated the sky here. It was just a temporary flare for excess gas, but it signaled a new era in energy production.

Across the bay from this small fishing town, where reindeer wander the streets, one of the world’s most advanced natural gas plants is coming to life.

Within weeks, gas will start crossing the ocean in specially designed ships, feeding into the pipeline network for the American East Coast. Before Christmas, furnaces in Brooklyn and stoves in Washington will be burning the gas. It will be the first commercial energy production from waters north of the Arctic Circle.

As global demand soars and prices rise, energy companies are going to the ends of the earth to find new supplies.

In Kazakhstan, petroleum engineers are braving wild temperature swings in the shallow waters of the Caspian Sea to tap the biggest oil discovery of the last 30 years. They are drilling wells six miles deep in the Gulf of Mexico. And on the island of Sakhalin, off far eastern Russia, they have drilled horizontal wells through miles of rock to produce oil from a stretch of ocean notable for giant icebergs.

But as the industry extends its reach, the quest is becoming more arduous. The cost of producing new oil and gas is rising fast, and companies are troubled by worsening delays. Drilling rigs are scarce. Engineers, geologists and petroleum specialists are in critically short supply.

And the politics of oil and gas are getting trickier, with producing countries demanding a bigger share of the revenue and growing angry about project delays that postpone their payments.

Industry executives say their ability to keep up with global demand is badly strained.

”We’re facing bigger risks and bigger difficulties when we go into new frontier regions,” said Odd A. Mosbergvik, a senior manager at the dominant Norwegian energy company, StatoilHydro. ”But this is why the oil industry is for big boys. It’s a big gamble.”

The industry’s new reach is shifting the economics of energy extraction. According to a recent study, discovery and development costs, a key indicator for the industry, tripled from 1999 to 2006, to nearly $15 a barrel.

Last year alone, companies spent $200 billion developing new energy projects worldwide, according to the study by the consulting firms John S. Herold Inc. and Harrison Lovegrove — an amount larger than the economies of 147 countries.

These higher costs mean that the industry needs higher energy prices to finance new projects. They are also constraining its ability to expand quickly.

”There are no easy barrels left,” said J. Robinson West, chairman of PFC Energy, an industry consulting firm in Washington. ”The only barrels are going to be the tough barrels.”

There is plenty of oil and gas still in the ground, energy executives say. But global consumption is rising so fast that they must keep looking for new sources. Despite worldwide concern over global warming and the role of fossil fuels in causing it, United States government specialists project that global oil and gas demand will increase by some 50 percent in the next 25 years.

At the same time, the big discoveries of the last three decades, like those in the North Sea and on the North Slope of Alaska, are drying up. This is leading oil companies to remote places like Hammerfest.

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