SumanSpeaks: Science and Technology:

2011-08-26T23:32:00.000-07:00

Fluid Mechanics:

Definition: Fluid Mechanics encompasses the study of all types of fluids under static, kinematic and dynamic conditions. The combination of experiments, the mathematical analysis of hydrodynamics and the new theories is known as ‘Fluid Mechanics’.

Fluid: A fluid is defined as a material which will continue to deform with the application of shear force however small the force may be. Generally matter exists in three phases namely (i) Solid (ii) Liquid and (iii) Gas (includes vapour). The last two together are also called by the common term fluids.

(i) Solids: In solids atoms/molecules are closely spaced and the attractive (cohesive) forces between atoms/molecules is high. The shape is maintained by the cohesive forces binding the atoms.When an external force is applied on a solid component, slight rearrangement in atomic positions balances the force. Depending upon the nature of force the solid may elongate or shorten or bend. When the applied force is removed the atoms move back to the original position and the former shape is regained. Only when the forces exceed a certain value (yield), a small deformation called plastic deformation will be retained as the atoms are unable to move to their original positions. When the force exceeds a still higher value (ultimate), the cohesive forces are not adequate to resist the applied force and the component will break.

(ii) Liquids: In liquids the inter molecular distances are longer and the cohesive forces are of smaller in magnitude. The molecules are not bound rigidly as in solids and can move randomly. However, the cohesive forces are large enough to hold the molecules together below a free surface that forms in the container. Liquids will continue to deform when a shear or tangential force is applied. The deformation continues as long as the force exists. In fluids the rate of deformation controls the force (not deformation as in solids). More popularly it is stated that a fluid (liquid) cannot withstand applied shear force and will continue to deform. When at rest liquids will assume the shape of the container forming a free surface at the top.

(iii) Gases: In gases the distance between molecules is much larger compared to atomic dimensions and the cohesive force between atoms/molecules is low. So gas molecules move freely and fill the full volume of the container. If the container is open the molecules will diffuse to the outside. Gases also cannot withstand shear. The rate of deformation is proportional to the applied force as in the case of liquids.

Vapour is gaseous state near the evaporation temperature. The state in which a material exists depends on the pressure and temperature. For example, steel at atmospheric temperature exists in the solid state. At higher temperatures it can be liquefied. At still higher temperatures it will exist as a vapour. A fourth state of matter is its existence as charged particles or ions known as plasma. This is encountered in MHD power generation.

COMPRESSIBLE AND INCOMPRESSIBLE FLUIDS:

If the density of a fluid varies significantly due to moderate changes in pressure or temperature, then the fluid is called compressible fluid. Generally gases and vapours under normal conditions can be classified as compressible fluids. In these phases the distance between atoms or molecules is large and cohesive forces are small. So increase in pressure or temperature will change the density by a significant value.

If the change in density of a fluid is small due to changes in temperature and or pressure, then the fluid is called incompressible fluid. All liquids are classified under this category.

When the change in pressure and temperature is small, gases and vapours are treated as incompressible fluids. For certain applications like propagation of pressure disturbances, liquids should be considered as compressible.
CONTINUUM:

As gas molecules are far apart from each other and as there is empty space between molecules doubt arises as to whether a gas volume can be considered as a continuous matter like a solid for situations similar to application of forces.

Under normal pressure and temperature levels, gases are considered as a continuum (i.e., as if no empty spaces exist between atoms). The test for continuum is to measure properties like density by sampling at different locations and also reducing the sampling volume to low levels. If the property is constant irrespective of the location and size of sample volume, then the gas body can be considered as a continuum for purposes of mechanics (application of force, consideration of acceleration, velocity etc.) and for the gas volume to be considered as a single body or entity. This is a very important test for the application of all laws of mechanics to a gas volume as a whole. When the pressure is extremely low, and when there are only few molecules in a cubic metre of volume, then the laws of mechanics should be applied to the molecules as entities and not to the gas body as a whole.

2011-08-14T10:05:00.000-07:00

How to make solar power 24/7

MIT team designs concentrated solar thermal system that could store heat in vats of molten salts, supplying constant power.

David L. Chandler, MIT News Office

The biggest hurdle to widespread implementation of solar power is the fact that the sun doesn't shine constantly in any given place, so backup power systems are needed for nights and cloudy days. But a novel system designed by researchers at MIT could finally overcome that problem, delivering steady power 24/7.

The diagram above shows the idealized arrangement of a vat of molten salt used to store solar heat, located at the base of a gently-sloping hillside that could be covered with an array of steerable mirrors all guided to focus sunlight down onto the vat. Image: Courtesy of Alexander Slocum et al.

The basic concept is one that has been the subject of much research: using a large array of mirrors to focus sunlight on a central tower. This approach delivers high temperatures to heat a substance such as molten salt, which could then heat water and turn a generating turbine. But such tower-based concentrated solar power (CSP) systems require expensive pumps and plumbing to transport molten salt and transfer heat, making them difficult to successfully commercialize — and they generally only work when the sun is shining.

Instead, Alexander Slocum and a team of researchers at MIT have created a system that combines heating and storage in a single tank, which would be mounted on the ground instead of in a tower. The heavily insulated tank would admit concentrated sunlight through a narrow opening at its top, and would feature a movable horizontal plate to separate the heated salt on top from the colder salt below. (Salts are generally used in such systems because of their high capacity for absorbing heat and their wide range of useful operating temperatures.) As the salt heated over the course of a sunny day, this barrier would gradually move lower in the tank, accommodating the increasing volume of hot salt. Water circulating around the tank would get heated by the salt, turning to steam to drive a turbine whenever the power is needed.

The plan, detailed in a paper published in the journal Solar Energy, would use an array of mirrors spread across a hillside, aimed to focus sunlight on the top of the tank of salt below. The system could be "cheap, with a minimum number of parts," says Slocum, the Pappalardo Professor of Mechanical Engineering at MIT and lead author of the paper. Reflecting the system's 24/7 power capability, it is called CSPonD (for Concentrated Solar Power on Demand).

The new system could also be more durable than existing CSP systems whose heat-absorbing receivers cool down at night or on cloudy days. "It's the swings in temperature that cause [metal] fatigue and failure," Slocum says. The traditional way to address temperature swings, he says: "You have to way oversize" the system's components. "That adds cost and reduces efficiency."

The team analyzed two potential sites for CSPonD on hillsides near White Sands, N.M., and China Lake, Calif. By beaming concentrated sunlight toward large tanks of sodium-potassium nitrate salt — each measuring 25 meters across and five meters deep — two installations could each provide 20 megawatts of electricity 24/7, which is enough to supply about 20,000 homes. The systems could store enough heat, accumulated over 10 sunny days, to continue generating power through one full cloudy day.

While exact costs are difficult to estimate at this early stage of research, an analysis using standard software developed by the U.S. Department of Energy suggests costs between seven and 33 cents per kilowatt-hour. At the lower end, that rate could be competitive with conventional power sources.

The team has carried out small-scale tests of CSPonD's performance, but its members say larger tests will be needed to refine the engineering design for a full-scale powerplant. They hope to produce a 20- to 100-kilowatt demonstration system to test the performance of their tank, which in operation would reach temperatures in excess of 500 degrees Celsius.

The biggest challenge, Slocum says, is that "it's going to take a company with long-term vision to say, 'Let's try something really different and fundamentally simple that really could make a difference.'"

Most of the individual elements of the proposed system — with the exception of mirror arrays positioned on hillsides — have been suggested or tested before, Slocum says. What this team has done is essentially an "assemblage and simplification of known elements," Slocum says. "We did not have to invent any new physics, and we're not using anything that's not already proven" in other applications.

Gershon Grossman, who holds the Sherman-Gilbert Chair in Energy at the Technion-Israel Institute of Technology, says this approach "includes several innovative CSP concepts." But, he adds, "the main advantage of this system is its ability to deliver power continuously, unlike other CSP systems, which are affected by clouds. This work is innovative and is expected to make a significant contribution" to the industry, he says.

Slocum emphasizes that this approach is not intended to replace other ways of harvesting solar energy, but rather to provide another alternative that may be best in certain situations and locations. Playing on the familiar saying about rising tides, he adds, "A rising sun can illuminate all energy harvesters."

Source: MIT News

2011-06-22T15:13:00.000-07:00

Smell-a-Vision

A proof-of-concept design shows that including a system to generate smells to accompany TV images is "quite doable." Karen Hopkin reports...

How many times has it happened to you: you’re sitting around watching a rerun of Friends and you think: Man, if only I could catch a whiff of that hazelnut mocchaccino they’re all pretending to drink. Well, me neither.

But engineers have now developed a programmable, odor-emitting device that, like it or not, brings us one step closer to realizing the dream of smell-a-vision. Their design is described in the journal Angewandte Chemie. [Hyunsu Kim et al, An X–Y Addressable Matrix Odor-Releasing System Using an On–Off Switchable Device]

TV tickles us with sight and sound. Why not smells? All you’d need is a box that would sit near the set and generate fragrances that match the images on screen: a woman’s perfume or a hot apple pie. But how big would the device have to be to generate thousands of odors?

To keep the dimensions down, the scientists envision using a 100-by-100 grid, so that just 200 on/off switches could unleash 10,000 stored bouquets. Which they say makes the whole thing “quite doable.”

The question then becomes: why would anyone want to do it? Presumably there are some things that are best left unsmelled. Because a sound cue is perfectly sufficient to tell us where Archie Bunker or Al Bundy has just been.

[The above text is an exact transcript of this podcast.]

2011-06-21T05:34:00.000-07:00

Modern-day sea level rise skyrocketing

Increase began with the Industrial Revolution

By Janet Ralof

This North Carolina house was filmed for the movie Nights in Rodanthe while researchers nearby studied the history of sea level rise in the area. The team found that seas have risen much faster in the last 150 years or so than in the previous two millennia.
Credit: A. Kemp/Yale University.

Sea levels began rising precipitously in the late 19th century and have since tripled the rate of climb seen at any time in at least two millennia, a detailed analysis of North Carolina marsh sediments shows.

“This clearly shows the recent trend is not part of a natural cycle,” says Ken Miller of Rutgers University in Piscataway, New Jersey, who was not associated with the analysis.

Andrew Kemp of the University of Pennsylvania and his colleagues spent five years plumbing salt marsh sediments that had remained largely undisturbed for millennia. Kemp, now at Yale, and his team drilled cores at two sites, unearthing the microscopic remains of single-celled shelled organisms known as foraminifera.

Foraminifera vary in their salt tolerance. So as sea level changed over millennia, so did the mix of species living at any given site, explains University of Pennsylvania coauthor Benjamin Horton. Knowing the modern-day distribution of foraminifera at various water depths along the modern-day coast, the researchers could infer past sea levels at the two core sites from the abundance of different species in successive sediment layers. Radioisotope dating showed that the sediments recorded 2,100 years of sea level history, the researchers report online June 20 in the Proceedings of the National Academy of Sciences.

“We know what sea level has done, in a broad sense, going back 20,000 years,” Miller says. But detailed records of what’s happened over the past 2,000 years have been spotty, he says.

The cores show that sea level at the North Carolina sites was largely unchanging from 100 B.C. until A.D. 950. Then sea level underwent a four-century rise averaging 0.6 millimeters per year. Sea level didn’t rise again until after 1865. Since then, it’s been climbing an average of 2.1 millimeters annually. And at least for the last 80 years, Horton says, “the fit with North Carolina tide gauge data is one to one: It’s perfect.”

The results validate the use of general equations relating past temperatures and sea level changes to predict sea level rise as the climate continues to warm, says Aslak Grinsted of the University of Copenhagen’s Centre for Ice and Climate.

“What’s great about this new record is that it’s really high resolution and continuous,” Grinsted says, “and quite consistent with records all around the world.”

Courtsey: Science News

2011-06-20T13:56:00.000-07:00

Discover Interview The Dark Hunter

Physicist Elena Aprile is certain that dark matter exists. She just hasn’t found it yet.

by Fred Guterl

Dark matter sounds like some physicist’s tall tale: There’s this invisible matter, see, and it has this powerful gravitational effect on galaxies. That’s why we know it exists. In fact, it outweighs ordinary matter by about five to one. Problem is, dark matter doesn’t reflect or absorb light, so we can’t see it. Oh, and it rarely interacts with conventional atoms, so we can’t feel it, either. However, we know it makes up a huge part of the universe, so we keep looking for it.

As mind-bending (and perhaps logic-challenging) as these ideas may seem, a lot of physicists are searching for this elusive matter. Elena Aprile is one of the leading lights in this dark business. She heads a prominent dark matter experiment called Xenon, which is based 5,000 feet underground in Italy’s Laboratori Nazionali del Gran Sasso, one of the world’s largest subterranean physics labs. Aprile, who is also a codirector of Columbia University’s Astrophysics Lab, started the project in 2007 with a detector called Xenon10. Since then she has upgraded to the more sensitive Xenon100. “I feel proud to have one of the best instruments in the field for detecting dark matter,” Aprile says of Xenon100. But the huge questions remain: What is dark matter, and how close are scientists to finding it? Aprile recently updated DISCOVER on how things are going in her search for the missing majority of the universe.

Seriously—what is dark matter?

The best answer is that we have no idea. We know dark matter is there. We’ve known it for more than 70 years. There was a 1933 paper by the Swiss astronomer Fritz Zwicky showing that visible matter is only a small fraction of the universe. Just 18 percent of the matter in the universe is composed of the stuff we know. The remaining 82 percent is what we call dark matter. Other discoveries in astronomy have since reinforced this view that something is missing. We know dark matter is there, but only from its gravitational effects. For example, the presence of dark matter helps explain why our galaxy is stable. The Milky Way is a disk that rotates like a merry-go-round. The question is, what keeps it from flying apart? Gravity, of course, but there is not enough visible matter in the galaxy to account for the amount of gravity needed to hold it together. That’s why we know that there must be other matter there that we can’t see.

What is dark matter composed of?

We think it’s made of a type of particle that doesn’t like to interact with normal matter [protons, neutrons, and other types of particles] very often. And it’s very heavy, very massive. Perhaps as heavy as an entire lead atom or even heavier. It’s probably a relic particle from the Big Bang, a member of a family of particles that we’ve named weakly interacting massive particles, or WIMPs.

How do we know dark matter consists of some new kind of particle?

Actually, we might be on the wrong track in thinking that dark matter is composed of a fundamentally new type of particle. That’s why we call it “the WIMP miracle.” The so-called standard model of particle physics, which lays out the way physicists think the universe works, has deficiencies. A lot of things, a lot of data, don’t fit. We have theories, such as supersymmetry and extra dimensions, that have been put forward to explain the things that are missing from the standard model or that don’t fit with the data we get. Some of the particles predicted by those theories are natural candidates to be dark matter because they have all the right characteristics. A particle called the neutralino, for instance, is a type of WIMP that’s a perfect candidate for dark matter in part because it doesn’t interact with other particles much, and that would explain why nobody has yet detected it.

If WIMPS don’t interact much with other particles, how can you find them?

The way we go about this search is to wait for a particle of dark matter to come into contact with our device, which is basically a pot of liquid xenon [an element that is used, in gas form, in the very bright headlights of many new cars] sandwiched between two detectors. We use xenon because it is one of the heaviest elements—meaning that each atom contains a lot of protons and neutrons—and that increases the odds that dark matter will interact with it. Whenever that happens, whenever a WIMP gets stuck in there, the xenon displays some remarkable properties. There will be a flash or scintillation of ultraviolet light. You can’t see it with the naked eye, so to detect this light, we have 178 extremely sensitive one-pixel cameras, called photomultipliers, above and below the liquid-xenon-filled detector. We also look for an ionization signal: If a dark matter particle rubs against a xenon atom, there will be electrons liberated and a charge produced. Those electrons drift upward through the liquid xenon to a positively charged anode [electric terminal], which produces a second flash of light that the cameras will detect.

That signal would tell you that a WIMP has finally made contact?

Well, we can extract a wealth of information from those two signals, including the speed of the particle, the location of the interaction, and the type of particle it was—an electron, a neutron, or dark matter. The more gently the particle touches the xenon, the more likely that it’s a WIMP.

But you haven’t definitely found one yet?

No. I mean, it constantly happens that you look at something and say, “Hey, what’s this?” and you think it could be dark matter. But we have always found an explanation for these events. Still, it’s important to consider the possibility that we might actually be looking right in the eye of dark matter.

How close are we to finding dark matter? Have others had hits, or possible hits?

There was news in December (article; live-blog) that another group of researchers, the Cryogenic Dark Matter Search (CDMS), had detected dark matter in a mine in Minnesota, but they saw a very weak signal. They recorded two events that they cannot fully explain as background noise. One of the events is very close to the threshold of noise. It’s not a detection; the collaboration itself doesn’t call it that. It’s the hint of a detection. There was initially a lot of excitement, but that has died down.

As for our group, we have collected data for several months now with Xenon100 and will continue through the summer. This powerful detector has the lowest background noise ever measured for any dark matter detector, and it is the largest-scale detector in operation. If the signal CDMS found was truly from dark matter, we’ll easily be able to confirm it this year. At the same time, particle physicists are looking for dark matter with the Large Hadron Collider in Geneva. We’re hoping they can tell us more about these particles in the next few years.

What is it like to search for something that you may never find?

It feels very exciting and almost like a duty. The fact that we don’t know if we will discover dark matter does not take away the necessity to try. The Italian particle physicist Carlo Rubbia, who was my doctoral thesis adviser at the University of Geneva, recently quoted Galileo at a conference on dark matter: Provando et riprovando—“Try and try again.” This is the basis of experimental science. We must try and try again to find the truth. If we stop because there is no guarantee that we will find anything, then we would never find anything again. In fact, in terms of dark matter, not finding anything is extremely important because it will make us find new roads to explore. We must keep searching for it with the best tools we have.

2011-06-18T16:52:00.000-07:00

Lightning Unleashes Antimatter Storms

You don't have to go all the way to supernovas to find natural events powerful enough to generate gamma rays says Shannon Palus

The powerful blasts of particles and light energy known as gamma-ray bursts come from violent cosmic events in deep space, such as stellar explosions and black hole collisions. But smaller-scale bursts called terrestrial gamma-ray flashes (TGFs) can occur much closer to home, erupting thousands of times a year in association with lightning strikes during storms in Earth’s atmosphere. Two satellites originally designed to observe gamma rays from space recently caught the atmospheric flares in action, revealing that they emit far more energy than previously thought and release streams of antimatter particles, which bear a charge opposite that of their normal counterparts.

In a study of 130 TGFs recorded by  the AGILE satellite, Italian Space Agency physicist Marco Tavani and colleagues report that the most energetic particles released carry four times as much energy as previous measurements detected, and hundreds of times as much as those produced by normal lightning strikes. In fact, Tavani describes a storm hurling photons into AGILE’s detectors as basically a giant particle accelerator in the sky. “It’s the equivalent of the Large Hadron Collider acting in the atmosphere for a fraction of a second,” he says. Next, Tavani plans to evaluate how TGFs might affect aircraft flying nearby.

Researchers working on another mission, NASA’s Fermi Gamma-ray Space Telescope, announced in January that about 10 percent of the particles fired off by TGFs consist of positrons—the positively charged antimatter twins of electrons. Because gamma rays can convert into electrons and positrons, physicists had predicted the antiparticles’ presence in the bursts, but until now they had never been directly observed. Astrophysicist Michael Briggs, a Fermi team member based at the University of Alabama in Huntsville, hopes such findings will aid in modeling how TGFs form. Currently, he says, scientists do not understand why some lightning strikes produce such mayhem while others do not.

Courtesy: Discover Magazine

2011-06-18T16:17:00.000-07:00

Animals Spinning Their Wheels
Nature anticipated mankind in the development of one of civilization’s fundamental machines.
By Adrian Bejan

No topic is more “mechanical engineering” than the wheel. When the wheel appeared, the movement of humanity jumped to new dimensions, higher speeds, longer distances, and less effort per unit of mass moved through a distance. If engineering is the kitchen of civilization, then the wheel is the key ingredient.
Today we take the wheel for granted, because it is everywhere. Older generations were more keenly aware of where we came from, and commemorated the wheel in the emblems of cities, business groups, trade unions, and engineering departments in universities. It is good that we maintain these images. The icon for “settings” on my iPhone consists of several wheels, even though there are no wheels inside.
Along with complacency comes arrogance. “Everybody knows” that nature did not invent the wheel. The famous Harvard biologist Stephen Jay Gould wrote a book about natural history and gave it the title Kingdoms Without Wheels.
The common wisdom is that humans invented the wheel and that it does not exist in nature. This idea places humans in a world distinct from and higher than all the other animals. Darwin must be rolling in his grave.
The common wisdom is wrong. But first, here is a brief reminder of why the wheel was such a dramatic change in how humans move. The work, W, spent on sliding a mass, M, through a horizontal distance, L, is equal to the weight, Mg, times L and a coefficient of friction, μ. With wheels placed between M and the ground, the work formula remained the same (W = μMgL) but the coefficient μ decreased considerably.

The constructal-law evolution of rolling locomotion, from the ancient wheel to

the modern wheel. The highest allowable stresses are distributed more uniformly, and the wheel becomes lighter and less costly in terms of the useful energy destroyed in order to carry it.

The time direction of this change, from high μ to low μ, is in accord with the constructal law of design and evolution in nature, which states that all flow systems (including human movement) persist in time by changing into configurations that flow more and more easily.
Humans and their loads found an easier way to move on the map, just as river basins find better tree-shaped flow designs every year. Seepage in the wet mud is not eliminated by the birth of the river channel, because seepage continues to improve flow by finding new channels. Similarly, when humans got their stuff off the ground and rolled with it, sliding was not eliminated. It persists today, at speeds and scales small enough to be comparable with the movement that existed before the wheel. For example, when we stock the shelves in grocery stores, we slide cans or boxes into place. On top of the old design of movement that slid loads across the ground, a better one with reduced friction was added.An Evolutionary Design:
The natural emergence of the wheel design can be predicted by using the constructal law in two ways. First, consider the evolution of the wheels made by humans. In the beginning, the wheel was a solid disk. The wheel and the ground made contact over a narrow strip on the rim. The stresses were distributed nonuniformly in the disk. The highest stresses were in the vicinity of the contact strip. Most of the wheel body was not stressed.

Less material is needed when the maximum allowable stresses are distributed more uniformly through the loaded structure. When the design requires less material, it becomes lighter. A single column with uniform cross-section requires the least material to support a weight. The stresses in the column are distributed uniformly. The volume of the column is a tiny fraction of the volume of the solid disk.
The column is a much lighter organ than the disk to carry on the vehicle, but one column is not enough to serve as a wheel. Three or more columns, a rigid rim, and a rigid track are required to prevent the body from falling. Fewer columns are lighter, and this constructal-law direction for easier movement in time is confirmed by the evolution of wheel technology from solid disk to spokes supporting a rim.
Second, imagine the horizontal movement of a terrestrial animal as a rolling body. Imagine the human body, or the front or back half of a quadruped.
The leg is a single column. Many bipedal creatures can stand still on one leg. There are many kinds of birds that sleep that way. To walk requires the forward movement—in essence, a falling forward from the one-legged stance.

The order of magnitude of the speed of falling forward is the same as the speed of falling down, namely V ~ (Rg)^1/2, where the distance above the ground (R) is the body length scale, which is the same as the length of the leg. The body mass scale is equal to the density of the body times the length scale of the leg cubed. Coincidentally, because M ~ ρR³, where ρ is the body density, the speed of locomotion is also recognized as V ~ M^1/6g^1/2ρ–^1/6, in agreement with the known characteristic speeds of all animals (runners, fliers, and swimmers), and with the world-record human speeds in running and swimming during the past 100 years.
To maintain this horizontal speed, the body design requires a second column, which must also have the ability to absorb shocks and to elongate itself to reposition the body weight to its traveling height (R). That’s why legs are most efficient when they come in pairs. The second leg is brought forward in time to catch the body before it falls too far or accelerates too much toward the ground. This function is like the cooperation of the spokes of a wheel. But because it can be done by consistently cycling two spokes, which are paired legs in animals, that is the way nature does it.
A third leg would continue the work of the first two, but it would increase by a factor of 3/2 the mass of the organs that the animal must carry along in order to have locomotion. Thus, the third beat of this rhythm is executed by the first leg, which swings outward, from behind the body, to take the position that the third leg would have occupied. This alternative is much lighter and faster, and (in accord with the constructal law) it is the natural design of rolling locomotion. The legs, as two columns swinging back and forth, perform the function of an entire wheel-rim-track assembly. They do it in record fashion—one wheel with just two spokes and with uniformly stressed material in each spoke. No wheel is stronger and lighter than this. The animal body is both wheel and vehicle for the animal mass that moves on the surface of the Earth.
Changing Speeds:
Nature evolved not only the design of wheel-like movement, but also the design for changing speeds.
Larger bodies move faster—that is, as the average of speed over a lifetime. The cheetah may be able to outrun any other land animal in a short sprint, but like all cats, it spends much of its time sleeping and watching. The cheetah can reach running speeds exceeding 100 km per hour for a distance of about 500 meters. Then it must rest or die.
The body mass of a cheetah is generally less than 40 kg. A medium-size man has at least twice that mass, and humans generally move more mass faster and farther than cheetahs over long periods of time. Considering the movement over a lifetime, humans are bigger, faster, and more economical vehicles of animal mass than cheetahs.
Because bigger means faster, greater speed could be found by increasing the height of the body mass above the ground.
Animal bodies have shapes with multiple scales. A simple body shape is the elongated body of a serpent. A quadruped’s body is much taller and more massive than a serpent’s, but it is also elongated: its length is greater than the height of its torso.

Evolution toward higher speeds points toward designs that are taller. This agrees with the evolutionary design of animal locomotion: quadrupeds occurred after swimmers and crawlers, not the other way around.
The animal becomes faster by orienting its longer dimension vertically, i.e. by making itself taller. The constructal-law direction is from long to tall, and this too agrees with the evolution of animal locomotion: bipedal locomotion evolved after quadrupedal locomotion. The vertical orientation increased the size of R. In the formula for speed, in which velocity correlates to the square root of R times g, a greater value of Rcontributes to higher speed.
There are many examples of the animal design for changing speeds. A human has two speeds: walk and run. A horse has three speeds: walk, trot, and gallop. The human and the horse increase their speeds by increasing the height from which their centers of gravity fall during each locomotion cycle.
From the walk to the gallop, the horse body movement changes abruptly such that the amplitude of the jump increases stepwise. The animal body with three different designs for movement (rhythm) is like one vehicle with one engine and a gearbox with three speeds.

Engineering and Nature:
The evolutionary designs of nature have arrived at wheel-like locomotion and at changes in body movement that result in changing speeds. The designs developed by humans are late comers to this long evolutionary sequence. They come from the same natural tendency to move on Earth more easily, to go with the flow. The human wheel and gearbox were not copied from nature. They are not fruits of biomimetics. These artifacts are part of our own evolutionary design for moving our mass on the landscape.
Engineering makes a contribution to understanding design in nature—a contribution that the other sciences cannot make. Biologists and geophysicists argue that one cannot witness and test “evolution” because of the enormous time scale of the phenomenon. Engineers bring an important idea to the current debate of design and evolution in nature. Yes, we can witness and test evolution during our lifetime, by studying the evolution of our designs and technologies. These evolutionary designs illustrate the time direction of the constructal law, which unites animate and inanimate design phenomena.

Note: Adrian Bejan is the J.A. Jones Distinguished Professor of Mechanical Engineering at Duke University. He can be reached at abejan@duke.edu.

Courtesy: ASME NEWS ONLINE

2009-07-17T07:36:00.000-07:00

Indian boffin creates camera with invisible flash that takes pics sans the glare

London: An Indian researcher along with a colleague has developed a camera that takes photos with an invisible flash of infrared and ultraviolet light points to a smarter way to take photos in the dark.
Dilip Krishnan and Rob Fergus at New York University made the camera to do away with intrusive regular flashes.
In order to make their 'dark flash' camera, the researchers modified a flashbulb to emit light over a wider range of frequencies and filter out visible light.
They also had to remove the filters which usually prevent a camera's silicon image sensor detecting IR and UV rays, reports New Scientist.
Krishnan and Fergus used colour information from a brief, flash-free photograph of the same scene taken quickly after the dark flash image to give the pictures more normal hues.

Krishnan and Fergus will present their work at the Siggraph conference in New Orleans in August.

2009-06-13T11:35:00.000-07:00

New mechanism may double a planet's lifespan

Washington : A team of scientists from the California Institute of Technology (Caltech) has come up with a mechanism that doubles the future lifespan of the biosphere of a planet, while also increasing the chance that advanced life will be found elsewhere in the universe.
As the sun has matured over the past 4.5 billion years, it has become both brighter and hotter, increasing the amount of solar radiation received by Earth, along with surface temperatures.
Earth has coped by reducing the amount of carbon dioxide in the atmosphere, thus reducing the warming effect.
According to Joseph L. Kirschvink, the Nico and Marilyn Van Wingen Professor of Geobiology at Caltech, the problem is that “we’re nearing the point where there’s not enough carbon dioxide left to regulate temperatures following the same procedures.”
Kirschvink and his collaborators Yuk L. Yung, a Caltech professor of planetary science, and graduate students King-Fai Li and Kaveh Pahlevan, say that the solution is to reduce substantially the total pressure of the atmosphere itself, by removing massive amounts of molecular nitrogen, the largely nonreactive gas that makes up about 78 percent of the atmosphere.
This would regulate the surface temperatures and allow carbon dioxide to remain in the atmosphere, to support life, and could tack an additional 1.3 billion years onto Earth’s expected lifespan.
Increasing the lifespan of our biosphere, from roughly 1 billion to 2.3 billion years, has intriguing implications for the search for life elsewhere in the universe.
The length of the existence of advanced life is a variable in the Drake equation, astronomer Frank Drake’s famous formula for estimating the number of intelligent extraterrestrial civilizations in the galaxy.
Doubling the duration of Earth’s biosphere effectively doubles the odds that intelligent life will be found elsewhere in the galaxy.
“It didn’t take very long to produce life on the planet, but it takes a very long time to develop advanced life,” said Yung.
On Earth, this process took four billion years.
“Adding an additional billion years gives us more time to develop, and more time to encounter advanced civilizations, whose own existence might be prolonged by this mechanism. It gives us a chance to meet,” said Yung.

2009-05-30T15:41:00.000-07:00

Sperm-like nano-devices may revolutionise drug delivery inside the body

London: A team of scientists, including an Indian-origin researcher, are working on remote-controlled nano-devices that look like sperm that may one day deliver drugs to where they are needed in the body.
Peer Fischer of The Rowland Institute at Harvard University has revealed that the nanopropellers will mimic the corkscrew motion of flagella, the structures some bacteria use to swim through water.
He and his colleague Ambarish Ghosh have revealed that their nanopropellers are made of glass.
The researchers further revealed that each of them has a spherical head 200 to 300 nanometres across and a corkscrew-shaped tail 1 to 2 micrometres long - less than one-tenth the length of a human sperm.
Ghosh and Fischer covered a silicon wafer with glass beads to make these propellers, before depositing a vapour of silicon dioxide onto them.
While doing so they spun the wafer, causing the silicon dioxide to form corkscrew-shaped tails on each bead. Finally, once the silicon dioxide had solidified they covered one side of the nanopropellers with cobalt.
Ghosh and Fischer say that the nanopropellers can be steered precisely.
"We control the coils that give rise to the magnetic field. By changing the magnetic field in three dimensions we can steer and propel the propellers," New Scientist quoted Fischer as saying.
The team have shown that a nanopropeller can push a silica bead over 1000 times larger than itself. They believe that their work may revolutionise drug delivery to specific areas of the body via the bloodstream, or even to conduct surgery.

2009-05-04T14:08:00.000-07:00

'Smart turbine blades' to improve wind power

Washington: In a new research, scientists have developed a technique that uses sensors and computational software to constantly monitor forces exerted
on wind turbine blades, a step towardimproving efficiency by adjusting for rapidly changing wind conditions.
The research, by engineers at Purdue University and Sandia National Laboratories, is part of an effort to develop a smarter wind turbine structure
"The ultimate goal is to feed information from sensors into an active control system that precisely adjusts components to optimize efficiency," said Purdue doctoral student Jonathan White, who is leading the research with Douglas Adams, a professor of mechanical engineering
and director of Purdue's Center for Systems Integrity.
The system also could help improve wind turbine reliability by providing critical real-time information to the control system to prevent catastrophic wind turbine damage from high winds.
The engineers embedded sensors called uniaxial and triaxial accelerometers inside a wind turbine blade as the blade was being built.
The blade is now being tested on a research wind turbine at the US Department of Agriculture's Agriculture Research Service laboratory in Bushland, Texas.
Such sensors could be instrumental in future turbine blades that have "control surfaces" and simple flaps like those on an airplane's wings to change the aerodynamic characteristics of the blades for better control.
Because these flaps would be changed in real time to respond to changing winds, constant sensor data would be critical.
Research findings show that using a trio of sensors and "estimator model" software developed by White accurately reveals how much force is being exerted on the blades.
"You want to be able to control the generator or the pitch of the blades to optimize energy capture by reducing forces on the components in the wind turbine during excessively high winds and increase the loads during low winds. In addition to improving efficiency, this should help improve reliability," said Adams.
"We envision smart systems being a potentially huge step forward for turbines," said Sandia's Rumsey.
"There is still a lot of work to be done, but we believe the payoff will be great. Our goal is to provide the electric utility industry with a reliable and efficient product. We are laying the groundwork for the wind turbine of the future," he added.
Purdue and Sandia have applied for a provisional patent on the technique.

2009-04-23T14:13:00.000-07:00

Biofuel crops can become invasive pests in tropical areas

Washington: In a new research, scientists have concluded that biofuel crops proposed for use in the Hawaiian Islands are two to four times more likely to become invasive pests in Hawaii and other tropical areas when compared to a random sample of other introduced plants.
The research was done by scientists with the University of Hawaii Pacific Cooperative Studies Unit, who examined the impact of unregulated planting of biofuel crops for their potential invasiveness and raised concerns about their impacts on Hawaii's environment.
Recent spikes in energy costs and political instability in many oil-rich regions of the world are driving a search for homegrown alternatives to traditional fossil fuels, such as coal, oil and natural gas.
Biofuel crops are often touted as a 'green' solution to U.S. dependence on foreign oil and have been promoted for stimulus package 'green jobs'.
Despite the potential benefits, researchers say biofuel crops actually might be aggressive invasive plants grown under the guise of beneficial crops.
The researchers used a weed risk assessment that examines a plant's biology, geographic origin, pest status elsewhere, and published information on its behavior in Hawaii to identify plants with a high risk of becoming invasive pests in Hawaii or other Pacific islands.
Despite these findings, researchers say some high risk biofuel crops could be grown if measures are implemented that reduce their risk of spreading out of control and causing unintended problems.
According to Christopher Buddenhagen, co-author of the study, 'By identifying the species with the highest risk, and pushing for planting guidelines and precautionary measures prior to widespread planting, we hope to spare the Hawaiian Islands and similar tropical ecosystems from future economic and environmental costs of the worst invaders while encouraging and promoting the use of lower risk alternative crops.'

2009-03-22T04:10:00.000-07:00

Higher Performance Electrical and Optical Integrated Circuits come closer to Reality

Washington: Scientists at the University of Illinois have moved a step closer to realising higher speed electronics and higher performance electrical and optical integrated circuits, for they have successfully created a microwave signal mixer made from a tunnel-junction transistor laser.
The researchers have revealed that their mixing device accepts two electrical inputs, and produces an optical signal that was measured at frequencies of up to 22.7 gigahertz.
They say that the frequency range was limited by the bandwidth of the detector employed in the measurements, not by the transistor device.
"In addition to the usual current-modulation capability, the tunnel junction provides an enhanced means for voltage-controlled modulation of the photon output of the transistor laser. This offers new capabilities and a much greater sensitivity for unique signal-mixing and signal-processing applications," said Nick Holonyak Jr., a John Bardeen Chair Professor of Electrical and Computer Engineering and Physics.
For making the device, the research team placed a quantum well inside the base region of a transistor laser, and then created a tunnel junction within the collector region.
"Within the transistor laser, the tunnelling process occurs predominantly through a process called photon-assisted absorption," said Milton Feng, the Holonyak Chair Professor of Electrical and Computer Engineering.
According to Feng, the tunnelling process begins in the quantum well, where electrons and holes combine and generate photons, which are then reabsorbed to create new pairs of electrons and holes used for voltage modulation.
"The tunnel junction makes it possible to annihilate an electron in the quantum well, and then tunnel an electron out to the collector by the tunnel contact," Feng said.
The transistor output is sensitive to third-terminal voltage control because of the electrons tunneling from the base to the collector, which also creates an efficient supply of holes to the quantum well for recombination.
"We are using the photon internally to modify the electrical operation and make the transistor itself a different device with additional properties," said Holonyak, who also is a professor in the university's Center for Advanced Study, one of the highest forms of campus recognition.
According to the researchers, high-speed signal mixing is made possible by the nonlinear coupling of the internal optical field to the base electron-hole recombination, minority carrier emitter-to-collector transport, and the base-to-collector electron tunneling at the collector junction.
The sensitivity of the tunnel-junction transistor laser to voltage control enables the device to be directly modulated by both current and voltage.
The researchers say that this flexibility facilitates the design of new non-linear signal processing devices for improved optical power output.
"The metamorphosis of the transistor is not yet complete. We're still working on it, and the transistor is still changing," Holonyak said.
The fabrication and operation of the mixing device has been described in the journal Applied Physics Letters.

2009-03-14T13:06:00.000-07:00

85,500 Solar Jobs Possible in Florida:
By Susan Salisbury

Harnessing solar energy in the Sunshine State has always seemed to make a lot of sense. Well, now a grass-roots group wants to put that to the test.
The San Francisco-based The Vote Solar Initiative, focused on advancing solar energy development in the U.S., estimates that 85,500 jobs -- from construction to engineering to marketing -- could be created if Florida adopts a proposed requirement that 20 percent of the state's electricity comes from renewable sources by 2020.
By May, the Florida Legislature is expected to consider the 20 percent renewable standard recommended by the Florida Public Service Commission. Now, about 2 percent of the state's energy comes from renewable sources.
Gwen Rose, deputy director of The Vote Solar Initiative, said the jobs estimate comes from a study by Navigant Consulting that showed more than 3,800 megawatts of solar power could be generated if the state goes to the 20 percent standard. According to Navigant, with each megawatt yielding 15 to 30 direct jobs, that translates into 57,000 to 114,000 direct jobs -- 85,500 is the mid-range.
Today, Vote Solar placed a job listing in the Classifieds section of newspapers around the state, including The Palm Beach Post, stating: "HELP WANTED: 85,000 electricians, engineers, sales to staff the new solar energy economy. Apply at Legislature. Ask for strong solar energy policies." "The nice thing about solar is that it is flexible, modular and quick to market," Rose said. "You get projects in on the ground really fast. If the renewable portfolio standard passes and the rules are in place, you could see development really accelerate by 2010." She said solar is flexible because solar power plants can be large enough to power a community, or small enough to be installed on the rooftops of a house.
Indeed, several South Florida companies are finding a market in rooftop photovoltaic power systems, as well as the more typical solar hot water and pool heaters.
Yann Brandt, vice president of Advanced Green Technologies in Fort Lauderdale, said a typical residential solar power system costs from $30,000 to $40,000 to install, but that the homeowner receives $25,000 to $30,000 in federal tax incentives and state rebates. Among the company's projects were 26-kilowatt systems at the Publix Super Markets Greenwise stores in Boca Raton and Palm Beach Gardens.
"Solar is the infrastructure project of the 21st century. ... It offers us the most shovel-ready projects of all," Brandt said. "We have the roof space and solar is readily available." Brian Betron agreed. The solar energy consultant for Jupiter-based Abundant Energy said the company recently installed the town's first photovoltaic system.
For Jupiter homeowners Brian and Emily O'Mahoney, having the system installed about a month ago was all about being green. Emily O'Mahoney, a landscape architect, is LEED certified.
"We calculated it for a size where it should offset our electrical usage completely," Brian O'Mahoney said. "I don't actually believe that will happen. (But) it will definitely save us quite a bit." Betron agrees that the solar industry would be boosted if the state adopted the 20 percent standard.
"There is so much potential here in the state of Florida," he said "For just the residential facilities, or homes, only half of 1 percent have any type of solar installed."

2009-03-07T21:57:00.000-08:00

FOCUS ON GLOBALIZATIONA Shift in Engineering Offshoring

The transfer of R&D resources to low-wave countries may portend major changes for engineers in developed nations.

By Alan S. Brown

Companies have been offshoring manufacturing for decades. Today, however, corporations are sending engineering work abroad as well, by outsourcing work to offshore vendors or assigning it to overseas divisions.

If this is a seismic change in the engineering profession, so far mechanical engineers have only felt the initial tremors. The trend is most pronounced in information technology, computing, and consumer electronics, where U.S., European, and Japanese firms have hired hundreds of thousands of programmers and engineers in China, India, and other developing nations. Computer and cellphone manufacturers increasingly outsource product design and engineering to original design manufacturers in China and Taiwan.

Many IT organizations not only outsource projects overseas, but rely on a small army of contract workers from overseas (on H1-B visas) to staff U.S. offices. Some companies require domestic IT employees to train their replacements (who will return overseas with their jobs) in order to retain severance benefits. A recent survey of 10,000 workers by the Stern and Wharton business schools found 8 percent of IT workers fired or involuntarily transferred due to offshoring.

Similar practices are not as common in mechanical engineering. Yet the trends are moving in the same direction. Companies like Caterpillar, Daimler, General Electric, General Motors, Honeywell, Siemens, Matsushita Electric, and IBM have all built massive engineering facilities offshore. Many companies also outsource engineering to offshore vendors.

[Photo: Manufacturing profits helped build Shanghai's skyline. Studies show companies that offshore manufacturing tend to offshore engineering too].

Corporations justify offshoring easily. They need local engineers to enter developing markets. They claim they cannot find enough skilled engineers at home. They want to speed up product introductions. They believe offshoring cuts costs.

There are other reasons too, some rarely enunciated. Many CEOs of public companies feel pressure from Wall Street analysts to show cost-cutting offshoring strategies. China demands technology transfer in exchange for access to its markets. Engineering must follow manufacturing abroad to achieve real efficiencies. Managers can hire four or five engineers overseas for the cost of one at home.

Offshoring is reaching critical mass in many engineering fields. Offshore engineers are bright, highly motivated, and have climbed the skill ladder rapidly. Engineering centers founded to create 3-D CAD files and adapt products for local markets are now tackling more complex projects as well as true research. Increasingly, large corporations see overseas divisions as new centers of excellence, and offshore vendors as low-cost sources of design and engineering.

This may sound familiar. After all, multinationals increasingly promote talented individuals from all over the world. Many have outsourced engineering projects for decades.

Yet many researchers believe offshoring today differs from past practices in one very important way: Many multinationals are making massive investments overseas at the expense of investments at home. This massive transfer of knowledge and capabilities overseas is depleting engineering capacity in developed nations.

This raises fundamental questions: Are multinationals transferring too much technology to potential competitors? Will fledgling engineers in developed countries become leaders if the jobs where they learn technical leadership skills are offshore? Can multinationals remain close to customersСand control project design and specificationСif they outsource vital engineering capabilities?
Multinational companies often answer questions like these by affirming that offshoring enables them to reduce costs to consumers, increase market share, and use profits to create more high-paying jobs. They are, after all, not citizens of one country, but of many countries, and their job is to maximize shareholder value.
ELUSIVE NUMBERS
European and Japanese engineers tend to have more job protection than American engineers, and U.S. corporations are believed to be in the forefront of offshoring. But there is little hard data on engineering. In 2005, the National Academy of Engineering asked Timothy Sturgeon, a research Fellow at MIT’s Industrial Performance Center, to assess data on offshoring.
“I documented something everyone already knew. There isn’t any data on any of this stuff,” he said. “I was shocked to find how big the holes were. The U.S. Bureau of Economic Analysis collects data on 16,000 product categories versus 17 service categories. I can find a synthetic thread twisted left, but all engineering is lumped under ‘Business, professional, and technical services.’”
Lori Kletzer, an economist at University of California, Santa Cruz, agrees. “It’s almost to the point of being ridiculous,” Kletzer said. “We’ve been a service economy for a long time, but we’re still focused on things that cross a border and require a customs form.”
In a recent study, two Rand Corp. researchers, James Hosek and Titus Galama, argued that the United States still leads the world in science and technology, accounting for 40 percent of global R&D spending. Compared with other industrialized nations, it filed 38 percent of all new patents, employed 37 percent of all researchers, and wrote 63 percent of the most highly cited research papers.
Yet Hosek and Galama cannot determine where U.S. corporations spend their R&D dollars, which amount to two-thirds of all U.S. R&D funding.
[Photo: Taiwan manufactures 90 percent of the world's laptop computers and does an increasing amount of design and engineering].
Often, information comes in illuminating bursts. A recent National Academy of Engineering report noted that employment and exports of Indian software services firms grew 30 to 40 percent annually over the past decade. And 18 of the top 20 U.S. semiconductor companies have built design centers in India, half since 2004.
Ron Hira, an assistant professor of public policy at Rochester Institute of Technology, notes that IBM’s Indian operations grew to 73,000 employees by the end of 2007, from 9,000 in 2003. IBM expects to reach 100,000 workers, mostly technical, by 2010. “That rivals the roughly 120,000 people IBM employs in the U.S.,” he noted.
Hira points to a 2007 survey of 248 American and European R&D managers undertaken for the National Academies’ Government University Industry Research Roundtable. The managers expected R&D employment to grow in India and China. More thought it would decline than grow in the United States. Most managers said they planned to keep emerging technologies at home while offshoring familiar science.
To understand offshoring better, Leonard Lynn, a professor of management policy at Case Western Reserve University, and Hal Salzman of the Urban Institute, a Washington think tank, turned detective. They interviewed more than 200 engineers and managers at 41 multinational companies and eight smaller firms at 67 sites in 14 countries. They covered 23 electrical or electronics sites, 20 auto or aerospace facilities, 19 information technology offices, and five medical or pharmaceutical centers.
“Based on our case studies, we are concerned about U.S. firms taking their market leadership for granted while undercutting their engineering infrastructure,” Lynn said.
Lynn is skeptical of many offshoring practices and assumptions. He said that, in once case, a multinational company’s division specializing in large administrative software systems announced plans to develop new software. When financial analysts criticized it for not having a cost-cutting offshoring strategy, senior management decided to outsource a percentage of the business. “It was not so much a strategy as a quota,” Lynn said.
The company, which Lynn calls ALL-IT to protect its identity, began outsourcing more of the project while downsizing U.S. staff. It had planned to keep core development in the United States. Yet as technical hurdles arose, the company no longer had the U.S. programmers to tackle them. It had to send more work overseas. By 2006, the company’s U.S. programmers were maintaining legacy systems while its Indian center was creating next-generation software.
The company, a systems integrator, remained close to its customers. Yet it often brought in staff from Indian contractors to help solve customer problems. “It was becoming apparent to customers where the real expertise lies,” Lynn said. ALL-IT’s managers told Lynn that they learned systems integration by moving up the ranks, but those jobs were being outsourced.
According to Lynn, “If you neglect the infrastructure back home, you lose capabilities. If you don’t have managers who worked their way through the entire system, then offshore engineers have to take over more leadership roles.”
Lynn and Salzman also studied a heavy electrical equipment manufacturer and a power systems company, which did a better job of safeguarding core technology. Both companies tapped Chinese or Indian nationals in top engineering management to lead their ventures overseas. The facilities started with limited agendas, like supporting a local factory or doing enough research to justify Chinese government contracts. Over time, though, their performance and the relationship of their managers with executives at home enabled them to expand their operations.
VALUE CHAINS
For many companies, offshoring engineering is an extension of outsourcing, a business model that calls for companies to concentrate on core businesses and contract peripheral projects to vendors. Companies that have prospered under this model often control the point where value is added to a product, often through engineering.
Take, for example, Apple. Its ability to develop proprietary technologies makes it a winner, said Kenneth Kraemer, the former director of the Center for Research on Information Technology and Organizations at the University of California, Irvine. He estimates that Apple captures approximately 30 to 35 percent of the value of each iPod it sells. Its U.S. and Japanese vendors, which supply high-tech components, receive most of the rest. China, which assembles the iPod, earns less than 5 percent.
Kraemer estimates that the iPod created 40,000 jobs. Only 12,000 to 14,000 jobs are in the United States, roughly half in engineering or management. Yet U.S. workers earn 2.5 times more than non-U.S. workers. “In Asia, the jobs are mostly very low cost labor, with relatively few engineering and management positions,” Kraemer said.
Even in a commodity business like PCs, some companies have proprietary advantages. Intel, which makes processors, and Microsoft, which develops operating systems, profit more than the PC makers themselves, Kraemer said.

Hewlett-Packard and Dell have dominated the notebook computer market by leveraging the value chain, MIT’s Sturgeon added. This is true even though Taiwanese companies make more than 90 percent of the world’s notebooks and do an increasing amount of design and detailed engineering. “One Taiwanese executive once told me that no foreign PC maker ever kept its market share in the United States,” said Sturgeon.
This is because Dell and HP are strong marketers and use their position atop the value chain to cut costs aggressively. In notebooks, Sturgeon said, Microsoft and Intel standards determine most of the functionality. “That makes capabilities generic and parts substitutable, so HP and Dell can play one component manufacturer off against the other,” he explained.
Automakers tried to do the same thing, but with less success. Each automotive subsystem requires extensive customization. “This makes it very difficult for automakers to specify what they want suppliers to do,” Sturgeon explained. “They have to trade tacitСuncodified, mushy, analogСinformation. They sit around conference tables, look at drawings, and there’s lots of trial and error. It raises the transaction cost.
“You need a special relationship with your suppliers to make this work. The Japanese are comfortable with these long-term, trust-based relationships. But U.S. automakers wanted a market relationship, and this leads to dysfunctional interactions. Since 1992, 37 Tier 1 and 2 suppliers have gone bankrupt, and not one of them was Japanese.”
Despite the need for hands-on engineering at home, automotive work continues to surge offshore. Technology centers support manufacturing operations in China and do R&D in India. General Motors, for example, hired 400 researchers in Bangalore within two and a half years. “If you look at their Internet job postings, they are certainly doing sophisticated research. It’s not for the Indian market, but for global markets and the United States,” said Martin Kenney, a professor of Human and Community Development at the University of California, Davis.
In 2005, an Indian multinational, Tata Group, acquired Incat International plc, an engineering contractor headquartered in Novi, Mich., and London, U.K. Tata, a major manufacturer and IT services supplier, has Incat’s experienced engineers interact with automakers at their facilities and coordinate the flow of engineering work to India.
“Some people tried the offshoring model and found they couldn’t make it work,” said Incat’s head of worldwide delivery, Kevin Fisher. “We can help an OEM with specific parts, like closures or trim, or go from design release to digital manufacturing.” He said Incat is close to signing a large engineering contract with a major automaker.
BUMPS ON THE ROAD
Even as multinationals send engineering abroad, some researchers question some of offshoring’s fundamental assumptions. “You would assume that big companies with smart people running them would do a cost-benefit analysis of offshoring,” Lynn said. “It was not always that sophisticated. They would say, ‘An engineer in India costs one-fifth as much as an engineer here, so the more engineers, the more benefit.’ ”
Lynn said, however, that he talked with two IT firms that estimated that it took five offshore workers to do the work of three U.S. employees. Offshoring also carried additional overhead, such as rework due to misunderstandings, additional management for coordination, and the cost of travel (up to $10,000 or more per person per trip).
“One engineering manager at a household products company told me that when they sent a team to China or reworked a project, they assigned the cost to U.S. operations,” Lynn said. “That made U.S. costs look higher and offshore costs lower.” Managers in other companies told similar tales.
Another company was surprised to find its Indian contractor rotating personnel so more employees could gain experience by working for a multinational client. “The U.S. engineers would fly to India, get to know someone, and the quality of work would go up,” Lynn said. “Then the contractor would rotate personnel and they’d have to make another trip. They were spending their money to train their contractor.”
Kenney notes that until the recession, rapid inflation of Indian IT salaries actually caused many European firms to relocate services in Eastern Europe because costs were similar and the location closer. Lynn believes the true cost advantage of offshoring is more like 15 percent rather than the 50 or 80 percent often claimed.
Yet Lynn readily admits that high costs may be short-term issues of an immature business model. As companies gain experience, offshoring costs may fall. For companies that spend tens or hundreds of millions on R&D, the savings are too tantalizing to ignore.
Besides, developing nations have remade themselves before our eyes. China and India graduate armies of engineers. While quality varies, thousands are smart, hard working, and capable. “If you’re paying an engineer $700 per month, you can afford to train him for nine months. After two or three years, he’ll be equally productive as American workers,” said Vivek Wadhwa, an entrepreneur who is currently executive in residence at Duke University.
Wadhwa also said that Indian IT firms have developed effective corporate training programs. “The IT education you get out of Infosys is better than most of our top universities,” he remarked. Meanwhile, U.S. and European universities are rapidly setting up overseas branches to educate students in science, engineering, and medicine.'

'UNSTOPPABLE NOW’
The shift towards offshore engineering is clear in IT, PCs, and telecommunications. Other industries are being pulled offshore to support new factories, adapt products to local markets, and to seek cost advantages. “Globalization is unstoppable now, no matter how much we moan and groan,” Wadhwa said.
Kraemer agreed. He surveyed 400 companies and sees manufacturing pulling engineering offshore. “The more a company outsourced manufacturing, the more it outsourced the physical design and development of its products,” Kraemer said. His analysis finds that this benefits companies, their industries, and their products. But Kraemer added a note of caution: “In the long run, the real research will probably stay here, but everything else is on the table.”
What will happen next? Will multinationals continue to shift engineering to low-cost nations, or will they reach an equilibrium point? Will smaller companies, typically hotbeds of innovation, feel they must also move engineering offshore to keep up, or will they continue to innovate at home? Will engineering’s center of gravity shift to developing nations?
Ralph Gomory, a former vice president of R&D at IBM and past president of the Alfred P. Sloan Foundation, which supports research about science and society, thinks the interests of corporations and their countries have diverged.
“I’ve sat on corporate boards, and every board member believes it is his or her duty to maximize value for shareholders,” he said. “If offshoring is good for profits, then it is their dutyСand they use that wordСto take those jobs to other countries.”
[Photo: Bangalore, India, has become a global offshoring destination, graduating from fixing Y2K software bugs and converting 2D drawings into 3D CAD files to doing advanced software design and engineering research and development].
The United States, unlike China, Korea, Japan, or many European countries, makes few demands on its corporate citizens, Gomory said. This has enabled U.S. corporations to shift investments overseas. They have grown richer, but are they leaving the nation poorer?
Classical economists defend offshoring by calling on a centuries-old principle called comparative advantage. It states that countries are better off when they trade without restrictions, so each trading partner can specialize in what it does best rather than try to hang onto floundering industries. Eventually, trade settles into an equilibrium that benefits both partners.
In today’s globalized world, that equilibrium changes constantly. “Comparative advantage tells you nothing about whether today’s equilibrium is better than yesterday’s. Today, we’re consuming more value than we create. We’re not balancing our trade gap. Like a rich family that doesn’t work, we’re living off our inheritance,” Gomory said.
No one can predict how the current recession will affect the global model. According to Hira at RIT, “Companies have built up huge engineering capacities overseas. Now, with the recession, there’s overcapacity. So which part of your capacity do you lop off? The high-cost legacy capacity or the part that you just built?”
Hira’s prediction: “These firms will announce large layoffs and blame it on the recession. But the cuts will be unevenly distributed, so what looks like a layoff is really a geographic redistribution of a firm’s workforce.”
The landscape is clearly changing, but the future is far from clear. The United States, for instance, retains substantial engineering strengths. It remains the leader in R&D investment, sophisticated research, and engineering education. Its engineers remain capable, creative, and highly productive. Its students learn critical skills—teamwork, communications, business sense—that can give them an edge in a global economy.
As the economy improves, perhaps Indian and Chinese engineering salaries will soar once again, until costs reach a rough equilibrium. Perhaps multinationals will then assign R&D tasks based on capabilities rather than cost. Or they may pursue even lower-cost engineers, the way they relocated factories to seek cheaper labor. Perhaps innovation will move to other parts of the world. Perhaps it will simply diffuse across national borders, growing everywhere as the global economy expands.
Whatever happens, the world is definitely changing, and the engineering profession with it.

2009-03-05T18:43:00.000-08:00

How Many Dimensions In The Holographic Universe?

Viennese scientists are trying to understand the mysteries of the holographic principle: How many dimensions are there in our universe?

Some of the world's brightest minds are carrying out research in this area -- and still have not succeeded so far in creating a unified theory of quantum gravitation is often considered to be the “Holy Grail” of modern science.
Daniel Grumiller from the Institute of Theoretical Physics, Vienna University of Technology, can now at least unravel some of the mysteries of quantum gravitation. His results on black holes and gravitational waves are pretty mind-boggling - to say the least. Only recently he won the START prize and will use these funds to engage even more young physicists at the TU Vienna.
We perceive the space around us as three-dimensional. According to Einstein, time and space are inseparabely linked. Adding the time axis to our three-dimensional space makes our space-time-continuum four-dimensional. For decades, scientists have been wondering about the existence of additional dimensions so far hidden to our senses. Grumiller and his colleagues are trying the opposite approach: Instead of postulating additional dimensions, they believe that our universe could in fact be described by less than four dimensions.
“A hologram, as you find it on bank notes or credit cards, appears to show a three-dimensional picture, even though in fact it is just two-dimensional,” Grumiller explains. In such a case, reality has fewer dimensions than we would thinkit appears to have. This “holographic principle” plays an important role in the physics of space time. Instead of creating a theory of gravity in all the time and space dimensions, one can formulate a new quantum theory with one fewer spatial dimension. That way, a 3D theory of gravitation turns into a 2D quantum theory, in which gravity does not appear any more. Still, this quantum theory correctly predicts phenomena like black holes or gravitational waves.
“The question, how many dimensions our world really has, does probably not even have a proper answerprobably cannot be answered explicitly,” Grumiller thinks. “Depending on the particular question we are trying to answer, either one of the approaches may turn out to be more useful.”
Grumiller is currently working on gravitational theories which include two spatial dimensions and one time dimension. They can be mapped onto a two-dimensional gravitationless quantum theory. Such theories can be used to describe rapidly rotating black holes or “cosmic strings” – spacetime defects, which probably appeared shortly after the Big Bang.
Together with colleagues from the University of Vienna, Grumiller is organizing an international workshop, which will take place from April 14 to 24, 2009. Renowned participants, like scientists from Harvard, Princeton, the MIT and many other universities, reveal that the Viennese gravitation physicists are held in high regard internationally.

2009-02-20T13:47:00.000-08:00

Gamma ray burst: Astronomers spot strongest-ever explosion

The strongest gamma ray blast ever known, exceeding the power of 9,000 exploding stars, has been discovered by astronomers in the deep-space constellation Carina

The radiation burst occurred 12.2 billion light years away in deep space, in the constellation Carina. Its light has taken most of the age of the universe to reach us.
Gamma ray bursts are the most luminous explosions in the universe. Scientists believe they occur when exotic massive stars run out of fuel and collapse to form a black hole.
Jets of material powered by processes that are not yet fully understood are thought to blast outwards at nearly the speed of light, generating intense gamma rays.
The new explosion, designated GRB 080916C, was spotted last year by the American space agency NASA's Fermi Gamma-ray Space Telescope, which is designed to detect gamma radiation.
Astronomers soon discovered that the gamma ray burst belonged in the record books.
The short-lived blast, described in the online version of the journal Science, was more powerful than nearly 9,000 ordinary supernovae, or exploding stars.
Scientists calculated that the material emitting the gamma rays must have been moving at 99.9999 per cent the speed of light.
The explosion was enigmatic as well as spectacular due to a curious time delay separating the highest-energy emissions from the lowest.
Scientists are still trying to understand the reason for the time delay, which may have a straightforward physical cause or be due to peculiar quantum effects.
Professor Peter Michelson, a member of the Fermi Gamma-ray Space Telescope team, said: "Burst emissions at these energies are still poorly understood.
"This one burst raises all sorts of questions. In a few years, we'll have a fairly good sample of bursts, and may have some answers."

2009-02-13T14:27:00.000-08:00

Engineers revolutionise nano-device fabrication

Washington : Engineers have created a process that may revolutionise the manufacture of nano-devices from computer memory to biomedical sensors by exploiting a novel type of metal.
The material can be moulded like plastics to create features at the nano-scale and yet is more durable and stronger than silicon or steel. The search for a cost-effective and manageable process for higher-density computer chip production at the nano-scale has been a challenge.
One solution is making nano-scale devices by simple stamping or moulding, like the method used for fabricating CDs or DVDs.
This however requires stamps or master moulds with nano-scale features. While silicon-based moulds produce relatively fine detail, they are not very durable. Metals are stronger, but the grain size of their internal structure does not allow nano-scale details to be imprinted on their surfaces.
Unlike most metals, "amorphous metals" known as bulk metallic glasses (BMGs) do not form crystal structures when they are cooled rapidly after heating.
Although they seem solid, they are more like a very slow-flowing liquid that has no structure beyond the atomic level - making them ideal for moulding fine details, said senior author Jan Schroers of the Yale School of Engineering & Applied Science.
Researchers have been exploring the use of BMGs for about a decade, according to Schroers. "We have finally been able to harness their unusual properties to transform both the process of making moulds and producing imprints," he said. "This process has the potential to replace several lithographic steps in the production of computer chips."
Schroers says BMGs have the pliability of plastics at moderately elevated temperatures, but they are stronger and more resilient than steel or metals at normal working temperatures, said an Yale release.
"We now can make template moulds that are far more reliable and lasting than ones made of silicon and are not limited in their detail by the grain size that most metals impose," said Schroers.
This research was published in Nature on Thursday.

2009-02-08T11:32:00.000-08:00

Soon, electronic device that can become invisible

Washington: Scientists in California, US, have developed tiny electronic circuits that could pave the way for transparent electronics and other futuristic applications, including flexible electronic newspapers and wearable clothing displays.
In the new study, Chongwu Zhou and colleagues point out that although scientists have previously developed nano-sized transparent circuits, previous versions are limited to a handful of materials that are transparent semiconductors.
The researchers describe the development of transparent thin-film transistors (TTFTs) composed of highly aligned, single-walled carbon nanotubes - each about 1/50,000th the width of a single human hair.
They are transparent, flexible, and perform well.
Laboratory experiments showed that TTFTs could be easily applied to glass and plastic surfaces, and showed promise in other ways for a range of possible practical applications.
This research is a significant advance toward the long-sought goal of "invisible electronics" and transparent displays, which can be highly desirable for heads-up displays, wind-shield displays, and electronic paper.

2009-02-06T16:37:00.000-08:00

Hubble captures exceptionally deep view of unusual spiral galaxy

Washington: A spectacular new image captured by the Hubble Space Telescope has revealed an exceptionally deep view of an unusual spiral galaxy.
The image of the galaxy, which is in the Coma Galaxy Cluster, has been created from data taken by the Advanced Camera for Surveys on the NASA/ESA Hubble Space Telescope.
It reveals fine details of the galaxy, NGC 4921, as well as an extraordinary rich background of more remote galaxies stretching back to the early Universe.
The Coma Galaxy Cluster, in the northern constellation of Coma Berenices, the hair of Queen Berenice, is one of the closest very rich collections of galaxies in the nearby Universe.
The cluster, also known as Abell 1656, is about 320 million light-years from Earth and contains more than 1000 members.
The galaxies in rich clusters undergo many interactions and mergers that tend to gradually turn gas-rich spirals into elliptical systems without much active star formation.
As a result, there are far more ellipticals and fewer spirals in the Coma Cluster than are found in quieter corners of the Universe.
NGC 4921 is one of the rare spirals in Coma, and a rather unusual one. It is an example of an "anaemic spiral", where the normal vigorous star formation that creates a spiral galaxy's familiar bright arms is much less intense.
As a result, there is just a delicate swirl of dust in a ring around the galaxy, accompanied by some bright young blue stars that are clearly separated out by Hubble's sharp vision.
Much of the pale spiral structure in the outer parts of the galaxy is unusually smooth and gives the whole galaxy the ghostly look of a vast translucent jellyfish.
The long exposure times and sharp vision of Hubble also allowed it to not just image NGC 4921 in exquisite detail, but also to see far beyond into the distant Universe.
This image was created from 50 separate exposures through a yellow filter and another 30 exposures through a near-infrared filter using the Wide Field Channel of the Advanced Camera for Surveys on Hubble.

2009-01-28T13:56:00.000-08:00

Unlimited Information Storage may soon be a Reality

London: Researchers at Stanford University in Palo Alto, California, have used a feature of the electron to create holograms that pack information into subatomic spaces, which could one day lead to unlimited information storage.
"Our results will challenge some fundamental assumptions people had about the ultimate limits of information storage," graduate student Chris Moon, one of the authors of the work, told Nature News.
The research team at Stanford University used a feature of the electron - its tendency to bounce probabilistically between different quantum states - to create holograms that pack information into subatomic spaces.
By encoding information into the electron's quantum shape, or wave function, the researchers were able to create a holographic drawing that contained 35 bits per electron.
Compared to previous technologies, Moon and his colleagues saw a way to go smaller by using a quantum analogy to the conventional hologram.
They used the quantum properties of electrons, rather than photons, as their source of 'illumination'.
Using a scanning tunnelling microscope, they stuck carbon monoxide molecules onto a layer of copper - their holographic plate. The molecules were positioned to create speckled patterns that would result in a holographic 'S'.
The sea of electrons that exists naturally at the surface of the copper layer served as their illumination.
Just as water bouncing off stones in a show pond create a rippling wave patterns, these electrons interfere with the carbon monoxide molecules to create a quantum hologram.
The researchers read the hologram using the microscope to measure the energy state of a single electron wave function. They showed they could read out an 'S' - for Stanford - with features as small as 0.3 nanometers.
In addition to breaking the atomic limit for information storage, the researchers demonstrated one of the essential features of holography.
They stacked two layers, or pages, of information - in this case, an 'S' and a 'U' - within the same hologram. They teased out the individual pages by scanning the hologram for electrons at different energy levels.
This led the Stanford team to think about the creation of quantum circuits.
In encoding the 'S', the researchers were concentrating the electron density at certain points and energy levels, and a concentration of electrons in space is, in essence, a wire.
That led study co-author Hari Manoharan to think about using the holograms as stackable quantum circuits, which may eventually be needed to wire together a quantum computer.

2009-01-25T15:13:00.000-08:00

Soon, plastic solar cells with higher efficiency

Washington: A company in the US is developing plastic solar cells for portable electronic devices, which would have higher efficiency than the current technology.
Solarmer Energy Inc., the company in question, is on track to complete a commercial-grade prototype later this year, according to Dina Lozofsky, vice president of IP development and strategic alliances at Solarmer.
The prototype, a cell measuring eight square inches (50 square centimeters), is expected to achieve 8 percent efficiency and to have a lifetime of at least three years.
"New materials with higher efficiencies are really the key in our industry. Plastic solar cells are behind traditional solar-cell technology in terms of the efficiency that it can produce right now," Lozofsky said. "Everyone in the industry is in the 5 percent to 6 percent range," she added.
The invention, a new semiconducting material called PTB1, converts sunlight into electricity.
It has been invented by Luping Yu, Professor in Chemistry, and Yongye Liang, a Ph.D. student, both at the University of Chicago.
The active layer of PTB1 is a mere 100 nanometers thick, the width of approximately 1,000 atoms.
An advantage of the Chicago technology is its simplicity.
Several laboratories around the country have invented other polymers that have achieved efficiencies similar to those of Yu's polymers, but these require far more extensive engineering work to become a viable commercial product.
"We think that our system has potential," Yu said. "The best system so far reported is 6.5 percent, but that's not a single device. That's two devices," he added.
By combining Solarmer's device engineering expertise with Yu and Liang's semiconducting material, they have been able to push the material's efficiency even higher.
Silicon-based solar cells dominate the market today. Industry observers see a promising future for low-cost, flexible solar cells, said
According to UchicagoTech's Martin. "If people can make them sufficiently efficient, they may be useful for all sorts of applications beyond just the traditional solar panels on your house rooftop."

2009-01-25T03:15:00.000-08:00

Partial solar eclipse on Monday

New Delhi: As the country celebrates Republic Day on Monday, a partial solar eclipse will occur on Monday afternoon when the moon will pass directly between the earth and the sun.
The partial phase of the eclipse will be visible in southern India, the eastern coastal belt, most of North-east, Andaman and Nicobar Islands and Lakshadweep, Director of Nehru Planetarium N Rathnashree said.
The eclipse will be annular in regions covering south of Africa, Antarctica, South East Asia and Australia.
Annular solar eclipse occurs when the moon is farther from the earth than normal in its elliptical orbit and hence, its apparent size is not sufficient to cover the sun completely, Director of Science Popularisation Association of Communicators and Educators (SPACE) C B Devgun told a news agency.
Therefore, even though the sun-moon alignment is perfect, the moon will appear slightly smaller in diameter than the sun and a thin ring of sunlight will remain visible around the dark silhouette of the moon, he said.
Perfect-alignment of the sun and the moon means the apparent sizes of both the celestial bodies will be the same when viewed from earth.
The eclipse will begin at 1026 hrs though it will be visible in India only from the afternoon and end at 1630 hrs on Monday, passing through various stages.
The first city to witness the eclipse in India will be Kanyakumari at 1408 hrs while it will be visible from 1417 hrs in Port Blair, the last Indian territory in which the celestial phenomenon will continue till 1625 pm.

2009-01-25T03:11:00.000-08:00

Mars polar water is pure: Study

Paris: A large ice cap found at Mars' northern pole is "of a very high degree of purity," according to an international study reported by French researchers.
Radar data sent back by the US Mars Reconnaissance Orbiter (MRO) point to 95 per cent purity in this deposit, France's National Institute of Sciences of the Universe (Insu) said in a press release.
The Martian polar regions are believed to hold the equivalent of two to three million cubic kilometres" (0.47-0.72 million cu. miles) of ice, it said.
That makes it roughly 100 times more than the total volume of North America's Great Lakes, which is 22,684 cu. Kms (5,439 miles).
The study appeared in the journal Geophysical Research Letters, published by the American Geophysical Union.

2009-01-25T02:59:00.000-08:00

Japan launches rocket with greenhouse-gas

Tokyo: Japan fired the world's first greenhouse-gas monitoring satellite into space on Friday, a launch deemed crucial in the country's quest to compete globally in putting commercial satellites into orbit.
The black, white and orange H2A rocket took off from the space center on Tanegashima, a remote island in southern Japan.

The launch - the 15th for an H2A - had been delayed for several days because of bad weather.
Aboard the rocket was the world's first greenhouse-gas monitoring satellite called "Ibuki," which means "breath," and seven "baby satellites" - one developed by Japan Aerospace Exploration Agency, known as JAXA, and six created by university research centers and private industry.
The development cost for the greenhouse-gas monitoring satellite was 18.3 billion yen ($206 million), the government space agency said.
A successful launch was seen as crucial to Japan, which is trying to demonstrate that it has the capabilities with its domestically developed H2A rocket to compete in the global commercial launching business.
Japan has long been one of the world's leading space-faring nations and launched its first satellite in 1970.

But it has been struggling to get out from under China's shadow in recent years and gain a niche in the global rocket-launching business, which is dominated by Russia, the US and Europe's Arianespace.
JAXA says the latest launch itself cost about 8.5 billion yen ($96 million), the lowest ever. The standard for a competitive launch - set by Russia's Proton rocket - used to be around 7 billion yen, but has now risen to around 9 billion.
JAXA officials said the agency has already selected four other piggybacks for a launch in 2011. They will be launched for free, but JAXA is considering charging a launch fee in the future.
Earlier this month, Japan got its first commercial order to launch a satellite on an H2A. The agreement - which targets a liftoff date after April 2011 - is with South Korea.

2009-01-25T01:02:00.000-08:00

A new way to produce hydrogen 'discovered'

Washington: Scientists have discovered what they claim is a new way to produce hydrogen "by exposing selected clusters of aluminium atoms to water".
"Our previous research suggested that electronic properties govern everything about these aluminium clusters, but this new study shows that it is the arrangement of atoms within the clusters that allows them to split water.
"Generally, this knowledge might allow us to design new nanoscale catalysts by changing the arrangements of atoms in a cluster. The results could open up a new area of research not only related to splitting water, but also to breaking the bonds of other molecules, as well," lead scientist Evan Pugh of Penn State University said.
In their study, the scientists probed the reactions of water with individual aluminium clusters by combining them under controlled conditions in a custom-designed flow-reactor.
They found that a water molecule will bind between two aluminium sites in a cluster as long as one of the sites behaves like a Lewis acid, a positively charged centre that wants to accept an electron, and the other behaves like a Lewis base, a negatively charged centre that wants to give away an electron.

2009-01-24T22:14:00.000-08:00

Dear readers,
A very good morning!! It has been my dream to come up with a science & technology blog, since a long time; due to the growing importance of this field. We cannot dream of life today, with the thought of this major field.
Today, at last this dream of mine has come out to be true...Henceforth you will get the latest news on this interesting field of Science and Technology.
Hope you would love to read the contents of this blog...........Looking forward for your co-operation in the days to come.
Best wishes,
Suman Mukherjee
India.
www.sumanspeaks.blogspot.com