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Briefings

Listen Up, Bin Laden

Men claiming to be Osama bin Laden, the head of the al-Qaeda terrorist network, and Saddam Hussein, the former leader of Iraq, have released audio tapes exhorting their followers to battle on against the United States. And every time one comes out, various experts weigh in on its authenticity. But a researcher at the Oregon Health & Science University (OHSU) says there are so many reliable voice transformation technologies available that there is no way an expert can ever identify the voice on an audio tape with 100 percent accuracy. Technically, there's no way to be sure, says Jan van Santen, a mathematical psychologist at the university's School of Science & Engineering.

Detecting a fake tape is almost impossible—especially if the audio quality is bad to begin with, which is often the case with these tapes. The transformation method developed at OHSU requires an original recording of the person who's to be imitated. Then someone—a mimic using the same dialect, rhythm and inflection—is recorded reading the same text. After that, the mimic can say anything and the software transforms the new speech into a recording that has the same voice characteristics as the original. Van Santen says if a copycat used the same technology devised at OHSU, his team could spot it because they would know what “cues” to look for. But there are many other transformation technologies that could be used to achieve the same effect. Unless it was known which technology was used to fake a tape, spotting the fraud is nearly impossible.

Van Santen reckons the chances of a phony Saddam tape surfacing are greater than those of a fake bin Laden. That's because “Iraq is a more sophisticated country.” And, don't forget, Saddam has a history of employing doubles to represent him in public.

 

Flying Cleaner Skies

The use of hydrogen fuel cells in transportation usually refers to the powering of automobiles. But a new 3- to 5-year student-driven research program, sponsored by the nonprofit Foundation for Advancing Science and Technology Education and Diamond Aircraft of Austria, at the Florida Institute of Technology is developing a fuel-cell powered electric airplane.

Fuel cells are considered a clean and renewable power source for the future because they mix hydrogen with water to produce energy, and their only emission is water. The students will reconfigure a Diamond H-36 Dimona Motor-Glider, an aircraft now powered by a gasoline internal-combustion engine. Bill Chepolis, an associate professor in Florida Tech's School of Aeronautics, says the students will first design and analyze various performance and propulsion options, and will also consider human, safety, and environmental concerns. Finally, they will finish and test a prototype.

Although fuel cells appear to have great potential, automotive engineers are still grappling with some of the problems they present. Current versions are big and heavy, for one thing, and very expensive. Those issues also need to be addressed before they can be used on aircraft. “The problems are not insurmountable, but they have to be dealt with,” Chepolis says.

He thinks the auto industry will eventually lead the way to mass production, which will quickly lower costs. Initially, he adds, it's likely the first fuel-cell planes will be business jets. Fuel-cell commercial aircraft are in the long-term future. Chepolis says that not only would fuel-cell powered planes be nearly silent and clean but their widespread use would also improve airports. For instance, noisy aircraft—a common cause for complaints from residents who live near airports—would eventually disappear.

 

Phony Degrees Proliferate Down Under

AUSTRALIA—Education officials down under are worried that peddlers of bogus college degrees are hurting their reputation overseas. Thousands of students from Malaysia, Singapore, and increasingly China, flock to Australian colleges and universities every year attracted by the nation's reputation for high academic standards. But authorities fear that the proliferation of phony degrees may cause future students to decide to study elsewhere, which would be a big drain on the country's economy. There are currently about 145,000 students in the system, and foreign students are expected to pump almost $10 billion into the economy by decade's end.

The states of New South Wales and Queensland, whose prestigious schools attract many foreigners, are going after those hawking forged degrees from reputable schools and real degrees from dubious institutions that are in some cases no more than mail-drop addresses. “Students are provided with a degree using counterfeit university crests, serial numbers, and student identification numbers,” says New South Wales State Education Minister Andrew Refshauge. He says fake degrees from top universities can be easily obtained. Last year, New South Wales's Department of Fair Trading investigated nearly two dozen allegations about suppliers of worthless degrees. Queensland is in the process of passing a law toughening controls on education providers. The state's education minister, Anna Bligh, says that degree mill operators will face heavy fines and possible jail time. In addition, any new universities in the state will be monitored and their licenses reevaluated after five years.

Shady operators target foreign students in all disciplines, including engineering. The first priority for education officials is to guard their reputations but they also want to prevent students from purchasing worthless degrees. They want a degree from an Australian university to be worth far more than the paper it's printed on.

 

A COMPETITION WITH CONCRETE RESULTS

Concrete canoe. Sounds like a ‘60s heavy-metal band (think Led Zeppelin and Iron Butterfly). A concrete canoe is not a guitar-wielding outfit but an actual watercraft. And not only do concrete canoes float, they are as sleek and lightweight as the fiberglass and aluminum variety.

Every year since 1988, there is a National Concrete Canoe Competition, pitting university teams from across the country against one another in a contest that includes racing. It's jointly sponsored by the American Society of Civil Engineers and Master Builders Inc., a company that produces concrete admixtures. At this year's three-day event, held in Philadelphia in June and hosted by Drexel University, the University of Wisconsin's 145-pound, 22-foot canoe called the Chequamegon (pronounced shwa-me-gun) took top honors and $5,000 in scholarship money. Second place went to the Phoenix, a 160-pound canoe built by students from Canada's Universite Laval. The University of California-Berkeley's Bearkelium, weighing in at 160 pounds, came in third. Berkeley's team used a new construction technique called sheetcrete: Concrete is rolled into 1/8-inch sheets and then transferred to the form; vibration is used to join the sheets.

Twenty-five schools competed in the national competition this year. The canoes—which must be 90 percent concrete—sometimes weigh as little as 70 pounds and are designed on computers by civil engineering students. To make the flexible, thin canoe concrete, all sorts of admixtures are added to the portland cement mix: rice, tiny glass orbs, perlite, silica fume.

Teams' final scores have four components: Slalom/endurance and sprint races account for 30 percent; a design paper 30 percent; a business presentation 25 percent; and a final racing canoe, which must pass a floatation test, 15 percent.

Missing from this year's lineup was the historically dominating University of Alabama-Huntsville. The school has won five championships, more than any other school. This year, however, ‘Bama was bammed in a regional competition. Alabama's John Gilbert, 55, a professor of mechanical and civil engineering, is an expert in concrete canoeing. He even runs a Web site on the topic: concretecanoe.org. He praised Wisconsin's victory, calling it and the canoe “impressive.” But, he adds, behind the fun and games is some serious engineering. For the students, Gilbert says, it's a great exercise in teamwork and thinking outside the box. And the innovations they come up with, he adds, are useful for the industry. Mike Shydlowski, Master Builders president and CEO, says the students and the boats demonstrate “that concrete is a remarkable and versatile building material.” Indeed, Gilbert envisions concrete being used for such things as rocket casings and aircraft wing flaps. Hmm, a concrete rocket. Great name for a rock band.

 

EARLY DETECTION FOR LUNG CANCER

GLASGOW—One of the diabolical aspects of lung cancer is that it often spreads to fatal levels before symptoms appear, and early detection remains difficult. But thanks to technology devised to improve prospecting for gas and oil reserves, doctors may soon be able to discover the onset of lung cancer at a much earlier stage.

Researchers at the Optics Group at Glasgow University in Scotland have devised a unique sensor system that can sniff out ethane at levels less than one part per billion. Trace amounts of hydrocarbons, including ethane, naturally leak from oil and gas reserves. Physics professor Miles Padgett and his team worked on a system to monitor minute amounts of ethane; software they developed combines the ethane measurements with wind direction to pinpoint the source of the leak. The system uses an infrared laser to measure the gas. It can detect ethane by measuring the amount of infrared light absorbed at a specific wavelength.

So how does that lead to the detection of lung cancer? Humans react to cancer cells by producing higher levels of free radicals, chemicals that reduce cell membranes to hydrocarbons, including ethane. Physicians, including Dundee University's Chris Longbottom, who were visiting the Glasgow laboratory, immediately saw the potential of using the geologists' tool to screen for cancer. Connected to a breathalyzer, the ethane detection system appears to accurately diagnose lung cancer by sensing trace amounts of ethane. In clinical trials at Dundee's Ninewell Hospital, the breath of 50 patients was analyzed. Of 21 suffering from lung cancer, only one failed to produce a high ethane reading. But there was a problem with false negatives. Five patients who were cancer free also had measurable ethane readings. Padgett has begun a two-year project to improve the device.

 

WARBLING OUT A WARNING

Once upon a time, miners used canaries to determine if the air in mines was riddled with odorless, colorless, and tasteless poisonous gasses. If the canary died, it was time to run for the exit. Now researchers at the University of California–Berkeley have devised a “canary on a chip,” a micro-electromechanical device that could act as a warning system for biochemical attacks. The technology is a continuation of bionic chip research conducted by Boris Rubinsky, a professor of mechanical engineering and bioengineering, and a former grad student Yong Huang, who has a doctorate in mechanical engineering. Three years ago, they created a chip that linked a living biological cell with electronic circuitry. Now, they've determined, such a cell chip could act as a sensor. Rubinsky and Huang discovered that when a cell is exposed to a toxic agent, there is within milliseconds a spike of electrical resistance in its membrane as it dies. The chip monitors and records that electrical signature in real time. The chips are nonspecific, in that they will record a cell's fatal reaction to any toxin. Using wireless technology, the chip could set off an alarm. The chips could be embedded into vulnerable areas, like subway stations. Or placed on badges worn by soldiers. Huang says two problems remain to be solved: How to extend the life of the cells beyond 30 days and how to store the chips. Nevertheless, he adds, with proper funding the canary chip technology could be commercialized within two years.

 

FILL ‘ER UP WITH AIR , PLEASE

Now here's a concept for making the air that we breathe cleaner: Cars that are partly fuelled by air. Tsu-chin Tsao, a researcher at the University of California-Los Angeles (UCLA), working with engineers at the Ford Motor Co., has devised a plan for a hybrid car that uses air—not electricity—to boost fuel efficiency.

When cars slow down, their kinetic energy is transformed to heat by the friction brakes. Hybrid cars capture braking energy, convert it to electricity, store it in batteries and use the power to run a small electric motor that helps the car accelerate. That reduces the use of gasoline, a fossil fuel that when burned emits pollutants, primarily carbon dioxide. While the technology can cut emissions to impressively low levels, adding a second battery and motor is costly. They're also heavy, which forces automakers to reduce vehicle weight in other areas. Not surprisingly, the resulting hybrid cars are expensive, and that has slowed their acceptance in the marketplace. But Tsu-chin Tsao's air hybrid converts the braking energy to air, which is compressed and stored. When that air is allowed to expand, there is a burst of power that can help accelerate a car. And air hybrids need only a small tank—weighing about 66 pounds—to hold the compressed air. So his proposed technology is cheap as well as lightweight. It's also efficient: Computer modeling of a 2.5 liter, V-6 engine using the system indicated that it would improve fuel efficiency in urban areas by 65 percent and on the highway by 12 percent.

Tsao, a professor of mechanical and aerospace engineering at UCLA's Henry Samueli School of Engineering and Applied Science, says the key to air hybrids is a camless valve train. An engine's valve system lets in air and fuel, and releases exhaust. Tsao's system uses the engine to compress the air when it is not combusting fuel. That requires a valve timing system that can react almost instantaneously. That's accomplished by using actuators controlled by microchips. One minor hurdle that Tsao thinks can easily be surmounted is that air cools when it expands, and for propulsion purposes, it's best to have warm air. Tsao would like to build a prototype air hybrid car, but right now there are no funds available to do so. “The concept looks feasible,” he says. But without funding, it's a concept that's still floating in the air.

 

ON THE MARK

Biomechanical chips that rely on harmless bacteria could be used to build minuscule machines that deliver drugs to patients with pinpoint accuracy, say two University of Arkansas researchers. Mechanical engineer Steve Tung and bioengineer Jin-Woo Kim have developed a micro-pump that uses spinning bacteria to move minute amounts of liquid. The bacteria attach themselves to a flat surface and spin at a rate of 10 cycles per second. By fluctuating the bacteria's intake of a nutrient, the researchers can make the cells stop and go and change speeds. A series of the cells attached to a glass-walled chamber can pump 0.25 nanoliters of liquid a minute, according to their computer model. Tung says that preliminary measurements of flow velocity around the spinning cells—tracked by the insertion of a polymer bead into the flow—indicate that the model is correct. Now Tung and Kim are working on a polymer material system that will release the nutrient in a controlled fashion. One drawback: After 24 hours, the bacteria die. But, he adds, “We believe this can be improved once we develop the nutrient delivery system. However, this is not going to be a walk in the park, since we have to find out what is just the right amount of nutrient for maintaining cell spinning.” Tests using various chemicals, Tung adds, “have been very encouraging.” A potential plus to the bacteria pump: It should be low cost. The cells can be grown easily and cheaply. After all, tiny pumps shouldn't come with big price tags.

 

 
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