ArmoredD

Saturday August 9 2008 15:53 IST

Newindpress.com

An Indian double has caught global attention in the hypersonic race for cheap and cost effective launch technology.

Bidding for their rightful place among the world’s majors, two of the country’s premier agencies are in the advanced stages of proving scramjet (supersonic combustion ramjet) technology to meet their respective strategic needs.

While the Indian Space Research Organisation (ISRO) is working on the Reusable Launch Vehicle (RLV) for launching satellites, the Defence Research and Development Organisation (DRDO) is dreaming about a Hypersonic Technology Demonstrator (HSTD) to carry a range of weapons faster and farther.

Both have set a 2010 deadline. And both are in the pre-fabrication stage. But ISRO has the edge as it has already carried out a seven-second experimental combustion of a test engine. To state that both the projects are progressing at somewhat the same pace won’t be far off the mark.

Continue reading ‘A scramjet that cruises at 17290 km/hr’ »

Military Spot 

WASHINGTON, April 17, 2008 – The Defense Department today launched a five-year, Army-led cooperative effort to leverage cutting-edge medical technology to develop new ways to assist servicemembers who’ve suffered severe, disfiguring wounds during their wartime service.

The newly established Armed Forces Institute of Regenerative Medicine, known by the acronym AFIRM, will serve as the military’s operational agency for the effort, Dr. S. Ward Casscells, the assistant secretary of defense for health affairs, told reporters at a Pentagon news conference.

A key component of the initiative is to harness stem cell research and technology in finding innovative ways to use a patient’s natural cellular structure to reconstruct new skin, muscles and tendons, and even ears, noses and fingers, Casscells said.

Just more than 900 U.S. servicemembers have undergone amputations of some kind due to injuries suffered in wartime service in Afghanistan or Iraq, Casscells said. Other troops have been badly burned or suffered spinal cord injuries or significant vision loss.

“Getting these people up to where they are functioning and reintegrated, employed, (and) able to help their families and be fully participating members of society” is the task at hand in which AFIRM will play a major role, Casscells said.

AFIRM will fall under the auspices of the U.S. Army Medical Research and Material Command, based at Fort Detrick, Md., and it also will work in conjunction with U.S. Army Institute of Surgical Research, in San Antonio.

The Medical Research and Material Command is the Army’s lead medical research, development and related-material acquisition agency. It comes under U.S. Army Medical Command, which is led by Lt. Gen. Eric B. Schoomaker, the Army’s surgeon general. Schoomaker accompanied Casscells at the news conference.

“The cells that we’re talking about actually exist in our bodies today,” Schoomaker pointed out. “We, even as adults, possess in our bodies small quantities of cells which have the potential, under the right kind of stimulation, to become any one of a number of different kinds of cells.

For example, Schoomaker said, the human body routinely regenerates bone marrow or liver cells.

AFIRM will have an overall budget of about $250 million for the initial five-year period, of which about $80 million will be provided by the Defense Department, Schoomaker said. Other program funding will be provided by the National Institutes of Health, in Bethesda, Md., the Department of Veterans Affairs, and local public and private matching funding.

Rutgers University, in N.J.; Wake Forest University, in N.C.; and the University of Pittsburgh also will participate in the initiative.

Dr. Anthony Atala, a surgeon and director of the Institute for Regenerative Medicine at Wake Forest, also attended the news conference. Atala’s current research keys on growing new human cells and tissue.

“All the parts of your body, tissues and organs, have a natural repository of cells that are ready to replicate when an injury occurs,” Atala told reporters.

Medical technicians now can select cells from human donors and, through a series of scientific processes, can “regrow” new tissue, Atala said.

“Then, you can plant that (regenerated tissue) back into the same patient, thus avoiding rejection,” Atala said.

Special techniques are being developed to employ regrown tissue in the fabrication of new muscles and tendons, Atala observed, or for the repair/replacement of damaged or missing extremities such as noses, ears and fingers.

Continued advancement in regenerative medicine would greatly benefit those servicemembers and veterans who’ve been severely scarred by war, Schoomaker said.

The three-star general cited animals like salamanders that can regrow lost tails or limbs. “Why can’t a mammal do the same thing?” he asked.

This entry was posted on Friday, April 18th, 2008 at 3:41 am

13:30 16 April 2008

NewScientist.com news service

Colin Barras

Aircraft or submarines covered with an undulating skin able to change at a flick of a button would experience 50% less drag than conventional vehicles. This trick, which naturally occurs in dolphins, is now being tested by human engineers.

Turbulence is the bane of engineers’ lives. Chaotic air flow sets up unstable vortices and patterns in gases and liquids, increasing friction and drag.

Giving craft skin than can tweak its surface to impose order on these currents could dramatically cut the effect of drag, says Dimitris Lagoudas at Texas A&M University, US. Calming the chaotic waves makes them interact less with the skin. “The particles in the fluid stop “speaking” to the craft’s surface,” he says.

Lagoudas and colleagues have worked out that wrinkling the surface of a craft in the right way can cut problems. The surface must assume the shape of the ideal ordered surface wave it is trying to create, something that changes at different velocities.

Dolphin trick

It might seem counterintuitive to reduce drag by wrinkling the surface of a craft, but nature provides a precedent. “Dolphins induce their skin to wrinkle, so water won’t stick to them,” says Lagoudas.

After calculating that this approach would work, his team tested designs for an “active skin” that shifts to the shape of an ideal surface wave.

One design uses “legs” just beneath the skin that lengthen under the influence of an electric field, bending the skin upwards. By controlling the field around each piezoceramic leg, Lagoudas’ team can deform the skin into corrugations of right wavelength and amplitude to cut down drag.

The corrugations can be at most 30 micrometres high. “We measured flow velocities very close to the skin and derived the skin friction drag – we have seen reductions as much as 50%,” says researcher Othon Rediniotis.

Submarine suited

Lagoudas says the shape-shifting skin approach would work best as cladding for submarines. “It would be feasible to use this on aircraft but more challenging,” he explains. “The velocities are higher and so the travelling waves must be higher in frequency.”

“It’s a novel technique that has been demonstrated to work under lab conditions,” says Jonathan Morrison at Imperial College London, UK. “But implementing this in something the size of an aircraft would be pretty daunting.”

The complexity of the morphing skin might deter designers worried about the consequences were it to fail during flight or an underwater mission, says Morrison.

But Morrison he adds that the skin does not have to be so complex to be useful - corrugated skin with a fixed shape could also cut drag. “You could design it to be most effective while cruising,” he says, for example the speed an aircraft maintains for most of its flight.

Static skin like that would also have to be designed not to work under some conditions, he adds. “When you’re coming to land you actually want the drag.”

Journal reference: Smart materials and structures (DOI: 10.1088/0964-1726/17/3/035004)