Self-guided bullet prototype can hit target a mile away

Engineerblogger
Jan 30, 2012

A tiny light-emitting diode, or LED, attached to a self-guided bullet at Sandia National Laboratories shows a bright path during a nighttime field test that proved the battery and electronics could survive the bullet's launch. (Photo courtesy of Sandia National Laboratories)

Take two Sandia National Laboratories engineers who are hunters, get them talking about the sport and it shouldn’t be surprising when the conversation leads to a patented design for a self-guided bullet that could help war fighters.

Sandia researchers Red Jones and Brian Kast and their colleagues have invented a dart-like, self-guided bullet for small-caliber, smooth-bore firearms that could hit laser-designated targets at distances of more than a mile (about 2,000 meters).

“We have a very promising technology to guide small projectiles that could be fully developed inexpensively and rapidly,” Jones said.

Sandia is seeking a private company partner to complete testing of the prototype and bring a guided bullet to the marketplace.

Researchers have had initial success testing the design in computer simulations and in field tests of prototypes, built from commercially available parts, Jones said.

While engineering issues remain, “we’re confident in our science base and we’re confident the engineering-technology base is there to solve the problems,” he said.

Sandia’s design for the four-inch-long bullet includes an optical sensor in the nose to detect a laser beam on a target. The sensor sends information to guidance and control electronics that use an algorithm in an eight-bit central processing unit to command electromagnetic actuators. These actuators steer tiny fins that guide the bullet to the target.

Most bullets shot from rifles, which have grooves, or rifling, that cause them to spin so they fly straight, like a long football pass. To enable a bullet to turn in flight toward a target and to simplify the design, the spin had to go, Jones said.

The bullet flies straight due to its aerodynamically stable design, which consists of a center of gravity that sits forward in the projectile and tiny fins that enable it to fly without spin, just as a dart does, he said.

Computer aerodynamic modeling shows the design would result in dramatic improvements in accuracy, Jones said. Computer simulations showed an unguided bullet under real-world conditions could miss a target more than a half mile away (1,000 meters away) by 9.8 yards (9 meters), but a guided bullet would get within 8 inches (0.2 meters), according to the patent.

Plastic sabots provide a gas seal in the cartridge and protect the delicate fins until they drop off after the bullet emerges from the firearm’s barrel.

The prototype does not require a device found in guided missiles called an inertial measuring unit, which would have added substantially to its cost. Instead, the researchers found that the bullet’s relatively small size when compared to guided missiles “is helping us all around. It’s kind of a fortuitous thing that none of us saw when we started,” Jones said.

The four-inch-long bullet has actuators that steer tiny fins that guide it to its target. (Photo by Randy Montoya)

As the bullet flies through the air, it pitches and yaws at a set rate based on its mass and size. In larger guided missiles, the rate of flight-path corrections is relatively slow, so each correction needs to be very precise because fewer corrections are possible during flight. But “the natural body frequency of this bullet is about 30 hertz, so we can make corrections 30 times per second. That means we can overcorrect, so we don’t have to be as precise each time,” Jones said.

Testing has shown the electromagnetic actuator performs well and the bullet can reach speeds of 2,400 feet per second, or Mach 2.1, using commercially available gunpowder. The researchers are confident it could reach standard military speeds using customized gunpowder.

And a nighttime field test, in which a tiny light-emitting diode, or LED, was attached to the bullet showed the battery and electronics can survive flight, Jones said.

Researchers also filmed high-speed video of the bullet radically pitching as it exited the barrel. The bullet pitches less as it flies down range, a phenomenon known to long-range firearms experts as “going to sleep.” Because the bullet’s motions settle the longer it is in flight, accuracy improves at longer ranges, Jones said.

“Nobody had ever seen that, but we’ve got high-speed video photography that shows that it’s true,” he said.

Potential customers for the bullet include the military, law enforcement and recreational shooters. In addition to Jones and Kast, Sandia researchers who helped develop the technology are: engineer Brandon R. Rohrer, aerodynamics expert Marc W. Kniskern, mechanical designer Scott E. Rose, firearms expert James W. Woods and Ronald W. Greene, a guidance, control and simulation engineer.

Sandia's self-guided bullet

Source: Sandia National Laboratories

New Ideas Sharpen Focus for Greener Aircraft

Engineerblogger
Jan 30, 2012

Three proposed aircraft designs have varying levels of success in meeting tough NASA goals for reducing fuel use, emissions and noise all at the same time. Image credit: NASA

Leaner, greener flying machines for the year 2025 are on the drawing boards of three industry teams under contract to the NASA Aeronautics Research Mission Directorate's Environmentally Responsible Aviation Project.

Teams from The Boeing Company in Huntington Beach, Calif., Lockheed Martin in Palmdale, Calif., and Northrop Grumman in El Segundo, Calif., have spent the last year studying how to meet NASA goals to develop technology that would allow future aircraft to burn 50 percent less fuel than aircraft that entered service in 1998 (the baseline for the study), with 75 percent fewer harmful emissions; and to shrink the size of geographic areas affected by objectionable airport noise by 83 percent.

"The real challenge is we want to accomplish all these things simultaneously," said ERA project manager Fay Collier. "It's never been done before. We looked at some very difficult metrics and tried to push all those metrics down at the same time."

So NASA put that challenge to industry – awarding a little less than $11 million to the three teams to assess what kinds of aircraft designs and technologies could help meet the goals. The companies have just given NASA their results.

"We'll be digesting the three studies and we'll be looking into what to do next," said Collier.

Boeing's advanced vehicle concept centers around the company's now familiar blended wing body design as seen in the sub-scale remotely piloted X-48, which has been wind tunnel tested at NASA's Langley Research Center and flown at NASA's Dryden Flight Research Center. One thing that makes this concept different from current airplanes is the placement of its Pratt & Whitney geared turbofan engines. The engines are on top of the plane's back end, flanked by two vertical tails to shield people on the ground from engine noise. The aircraft also would feature an advanced lightweight, damage tolerant, composite structure; technologies for reducing airframe noise; advanced flight controls; hybrid laminar flow control, which means surfaces designed to reduce drag; and long-span wings which improve fuel efficiency.

The Boeing Company's advanced design concept is a variation on the extremely aerodynamic hybrid wing body. Image credit: NASA/Boeing

Lockheed Martin took an entirely different approach. Its engineers proposed a box wing design, in which a front wing mounted on the lower belly of the plane is joined at the tips to an aft wing mounted on top of the plane. The company has studied the box wing concept for three decades, but has been waiting for lightweight composite materials, landing gear technologies, hybrid laminar flow and other tools to make it a viable configuration. Lockheed's proposal combines the unique design with a Rolls Royce Liberty Works Ultra Fan Engine. This engine has a bypass ratio that is approximately five times greater than current engines, pushing the limits of turbofan technology.

Lockheed Martin's concept uses a box wing design and other advanced technologies to achieve green aviation goals. Image credit: NASA/Lockheed Martin

Northrop Grumman chose to embrace a little of its company's history, going back to the 1930s and '40s, with its advanced vehicle concept. Its design is a flying wing, championed by Northrop founder Jack Northrop, and reminiscent of its B-2 aircraft. Four high-bypass engines, provided by Rolls Royce and embedded in the upper surface of the aerodynamically efficient wing would provide noise shielding. The company's expertise in building planes without the benefit of a stabilizing tail would be transferred to the commercial airline market. The Northrop proposal also incorporates advanced composite materials and engine and swept wing laminar flow control technologies.

Northrop Grumman's concept is based on the extremely aerodynamic "flying wing" design. Image credit: NASA/Northrop Grumman

What the studies revealed is that NASA's goals to reduce fuel consumption, emissions and noise are indeed challenging. The preliminary designs all met the pollution goal of eliminating landing and takeoff emissions of nitrogen oxides by 50 percent. All still have a little way to go to meet the other two challenges. All the designs were very close to a 50-percent fuel burn reduction, but noise reduction capabilities varied.

"All of the teams have done really great work during this conceptual design study,” say Mark Mangelsdorf, ERA Project chief engineer. “Their results make me excited about how interesting and different the airplanes on the airport ramp could look in 20 years. Another great result of the study is that they have really helped us focus where to invest our research dollars over the next few years," he said.

NASA's ERA project officials say they believe all the goals can be met if small gains in noise and fuel consumption reduction can be achieved in addition to those projected in the industry studies. The results shed light on the technology and design hurdles airline manufacturers face in trying to design lean, green flying machines and will help guide NASA's environmentally responsible aviation investment strategy for the second half of its six-year project.

Source: NASA

Device Could Drive Down Solar's Cost

Technology Review
Jan 31, 2012
 

Power play: Inverters mounted to the bottom of each panel provide grid-ready power at a test site in Sunnyvale, California. Credit: ArrayPower

As solar panel manufacturers try to harvest more of the sun's energy for less, they face increasingly diminishing returns. At roughly $1 per watt, the cost of solar modules now represents less than a third of the total cost of commercial solar installations. To cut the total cost of solar power—currently $3.00 to $3.50 per watt—bigger gains will have to come from improvements in the power electronics, wiring, and mounting systems required for solar installations.

ArrayPower, a startup based in Sunnyvale, California, has developed a new type of solar inverter—the device that converts direct current (DC) power produced by solar panels to grid-ready, alternating current (AC) electricity—that it claims could significantly reduce the cost of solar power. The company says its "sequenced inverter" will reduce the cost of commercial solar by 35 cents per watt, or more than 10 percent, by lowering capital costs, simplifying installation, and increasing output.

Large-scale solar installations currently use either a single "central" inverter or a number of "string" inverters to convert power from groups of panels strung together in series. Both approaches, however, suffer from low efficiencies because of the way the panels are connected. In either scenario, if one panel is damaged or shaded from the sun, the system's entire output is diminished to the level of its lowest-producing panel.

ArrayPower seeks to maximize power output through a new type of inverter mounted to each panel. The device is similar to microinverters now used in residential solar installations. By converting DC to AC power at each module, microinverters maximize the power output of each module, thereby increasing system output by roughly 3 percent to 10 percent.

Microinverters are typically more expensive because they require sophisticated electronics to filter and smooth the alternating current coming out of each inverter. A major cost is an electrolytic capacitor, essentially a chemical battery that stores energy for short bursts, allowing the inverter to send out pulses of electricity that create an alternating current. Further, microinverters typically only yield single-phase AC electricity, an electric current that is suited for residential use but not commercial or utility use.
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Smart paint could revolutionise structural safety

Engineerblogger
Jan 31, 2012

Dr Mohamed Saafi. Credit: University of Strathclyde

An innovative low-cost smart paint that can detect microscopic faults in wind turbines, mines and bridges before structural damage occurs is being developed by researchers at the University of Strathclyde in Glasgow.

The environmentally-friendly paint uses nanotechnology to detect movement in large structures, and could shape the future of safety monitoring.

Traditional methods of assessing large structures are complex, time consuming and use expensive instrumentation, with costs spiraling into millions of pounds each year.

However, the smart paint costs just a fraction of the cost and can be simply sprayed onto any surface, with electrodes attached to detect structural damage long before failure occurs.

Dr Mohamed Saafi, of the University’s Department of Civil Engineering, said: “The development of this smart paint technology could have far-reaching implications for the way we monitor the safety of large structures all over the world.

“There are no limitations as to where it could be used and the low-cost nature gives it a significant advantage over the current options available in the industry. The process of producing and applying the paint also gives it an advantage as no expertise is required and monitoring itself is straightforward.”

The paint is formed using a recycled waste product known as fly ash and highly aligned carbon nanotubes. When mixed it has a cement-like property which makes it particularly useful in harsh environments.

Dr Saafi explained: “The process of monitoring involves in effect a wireless sensor network. The paint is interfaced with wireless communication nodes with power harvesting and warning capability to remotely detect any unseen damage such as micro-cracks in a wind turbine concrete foundation.

“Wind turbine foundations are currently being monitored through visual inspections. The developed paint with the wireless monitoring system would significantly reduce the maintenance costs and improve the safety of these large structures.

“Current technology is restricted to looking at specific areas of a structure at any given time, however, smart paint covers the whole structure which is particularly useful to maximise the opportunity of preventing significant damage.”

The research has been carried out at Strathclyde with Dr Saafi working alongside David McGahon, who initiated the work as part of his PhD project. With fly ash being the main material used to make the paint, it costs just one percent of the alternative widely used inspection methods.

David McGahon Credit: University of Strathclyde

A prototype has been developed and tests have shown the paint to be highly effective. It is hoped further tests will be carried out in Glasgow in the near future.

Dr Saafi added: “We are able to carry out the end-to-end process at the University and we are hoping that we can now demonstrate its effectiveness on a large structure.

“The properties of the fly ash give the paint a durability that will allow it to be used in any environment which will be a massive advantage in areas where the weather can make safety monitoring particularly difficult.

“The smart paint represents a significant development and is one that has possibly been overlooked as a viable solution because research tends to focus on high-tech options that look to eliminate human control. Our research shows that by maintaining the human element the costs can be vastly reduced without an impact on effectiveness.”

Source: University of Strathclyde

Scottish sailing engineers have designs on world speed record

The Engineer
Jan 23, 2012

The Abaqus software enabled Clarke’s team to consider many wing-sail design variables.  Credit: The Engineer

Simulation software from Dassault is being used to help a team of engineers get its extreme sailing boat - the V-44 Albatross - off the ground

The thrilling world of speed-sailing is responsible for some remarkable engineering innovations.

Back in September 2009, L’Hydroptere, a 60ft trimaran that ’flies’ above the surface on two fin-shaped hydrofoils, set a new world record for D-class vessels of 51.36 knots.

More recently, The Engineer reported on the Vestas SailRocket II, a glider-inspired boat with designs on the outright unpowered 500m record of 55.65 knots.

Now, in a bid to push the performance of extreme sailing boats even further, a team of Scottish engineers is using advanced simulation software to design and develop a bizarre-looking vessel that the engineers believe could soon break the near-mythical 60-knot barrier.

The boat, dubbed the V-44 Albatross, is the brainchild of Tim Clarke, engineering team leader at Scottish engineering consultancy Prospect Flow Solutions and founder of Verney Yachts.

Clarke explained that his idea was to create a single-hull craft and equip it with two wing-sails – structures that are literally a cross between a wing and a sail.

Made from composite materials, these wing-sails are able to switch both position and function as the boat tacks, becoming either a wing if horizontal to the water or a sail if vertical.

The approach has been tried before. The BMW Oracle, a trimaran sailboat, crushed its America’s Cup competitor in February 2010 using a wing-sail, while the Greenbird, a wing-sail-equipped land-yacht, set a new wind-powered land speed record of 126.4mph back in March 2009.

One of the challenges of developing a wing-sail is ensuring stability. While a conventional aircraft wing needs a tail to provide stability, this would add too much weight to a boat so wing-sail vessels typically achieve stability in other ways. For the BMW Oracle, a motorised trailing flap on a two-part structure was used, while the Greenbird deployed counterweights on the leading edge.

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Study finds manufacturers leading the drive to make sustainability a mainstream and profitable business practice

Engineerblogger
Jan 30, 2012

Credit: MIT News

As the United States seeks to reinvigorate its job market and move past economic recession, MIT News examines manufacturing’s role in the country’s economic future through this series on work at the Institute around manufacturing.

Nearly a third of companies now say that the adoption of sustainable practices has added to their profitability, according to a new MIT study — and manufacturing firms are in the vanguard.

Two-thirds of more than 2,800 companies surveyed by MIT Sloan Management Review say they have made sustainability a permanent agenda topic within their companies, up from 55 percent a year ago. And most respondents — based in 113 countries, and spanning a wide variety of sizes and industries — now see sustainability as “necessary to be competitive” in today’s economy. The study was conducted with the help of the Boston Consulting Group.

“The purpose of the report was to get a high-level view of how organizations are thinking about sustainability, and what they are doing about it,” says David Kiron, executive editor of MIT Sloan Management Review and a co-author of the report. “The attention and investment we see indicate the here-to-stay nature of sustainability for organizations everywhere.”

Manufacturing companies seem to be leading the way in this new approach: The survey found a particularly strong commitment to sustainability among “resource-intensive” producers of consumer products, commodities, chemicals and automobiles, as well as in energy-related companies. Respondents said product development was enhanced by a focus on sustainability, with 25 percent of companies citing “improved innovation in products and services” as among the top benefits they derived through sustainability.

Sustainable practices help cut energy and commodity prices by reducing waste, and in some cases have transformed companies from pariahs to paragons in the eyes of environmentally aware groups.

For example, paper-products manufacturer Kimberly-Clark has moved from criticism over its cutting of old-growth forests to a top Dow Jones Sustainability World Index ranking among makers of personal products, thanks to a concerted company-wide effort to make sustainability a priority. In addition to curbing former unsustainable practices, Kimberly-Clark now aims to reach 25 percent of sales by 2015 from “environmentally innovative products” — such as a new kind of toilet paper without a cardboard tube at the center.

In this study, Kiron says, sustainability encompassed not just reductions in energy use and emissions, but also more efficient use of water and natural resources; recycling of materials and careful attention to the full life-cycle impact of products, including their ultimate disposal; and attention to human rights in the treatment of employees and suppliers.

Kiron cites Starbucks’ focus on improving the sustainability of its coffee cups — of which the chain uses billions every year. To find innovative ways of reducing the waste associated with disposable cups, the company has convened conferences at MIT in an effort to come up with more environmentally friendly approaches. “There isn’t a hard line for them between environmental and social issues,” Kiron says. “It’s all part of being socially responsible.”

The study makes clear that the more deeply ingrained sustainability is within a company’s organizational structure, the more likely it is that these practices add to the company’s bottom line. For example, companies that say they have profited from their sustainability initiatives are 50 percent more likely to have a CEO strongly committed to the programs, are twice as likely to have a separate reporting process for sustainability, and are more than twice as likely to have a chief sustainability officer.

Sometimes, internal efforts to improve sustainability can lead to new product offerings. For example, UPS improved efficiency by designing the shipping industry’s most comprehensive tracking system. That made it possible to determine the exact carbon-emissions impact of each of the millions of parcels transported every day; the company now offers customers the option of paying a bit extra for a “carbon neutral” delivery, providing carbon offsets based on the actual path and types of vehicles by which a parcel travels to its destination. The service adds about a nickel to the shipping cost per parcel.

Another example of product innovation comes from automaker BMW, which set up a sustainability team that quickly attracted some of the company’s leading engineers. They ended up designing what they say is the world’s first electric car designed for mass production from the ground up. While it may be years before the new division — dubbed “Project i” — actually contributes to the company’s profits, BMW sees it as laying the groundwork for a leadership role in new automotive technology.

Sustainability turns out to have benefits for a company’s relations with its own employees as well, the study found. “In terms of retention and recruitment, having sustainability present on your agenda really has some cachet,” Kiron says, making it easier to attract and keep some of the most talented people.

Robert Eccles, a professor of management practice at Harvard Business School who was not involved in this study, says the MIT study “is one that executives in companies in every industry all over the world should read, and it identifies many of the key issues that need to be addressed.”

Eccles also says the report’s findings are congruent with those of research he has conducted with colleagues at Harvard and at London Business School.

“The research I am doing with a number of collaborators strongly supports the findings of this survey,” he says. “We get similar results in contrasting 90 ‘high sustainability’ companies with a matched set of 90 ‘low sustainability’ ones. The high sustainability companies also have distinctly better financial performance over an 18-year period of time.”

But Eccles adds that in order to benefit corporate performance, sustainability must be paired with innovation. “Without innovation, simply committing to improve sustainability performance will likely detract from financial performance,” he notes.

Eccles cautions that challenges remain in interpreting these findings: While savings in energy, water and resource use provide obvious benefits, he says, “these are easier to demonstrate and quantify than reputational and brand benefits.” He adds, “While the article rightly notes that mainstream investors are becoming interested in sustainability, this is not yet a trend and the markets still have their traditional short-term view.”

Source: MIT News

Startup Makes Peel-Off Solar Cells: Wafer-making method could mean cheaper solar power

Technology Review
Jan 30, 2012

Solar peel: This 25-micrometer film of crystalline silicon, deposited on a layer of metal, was produced using a new technique. Credit: Astrowatt

Today, most solar cells are made with a process that turns almost half of the raw material—highly refined and processed crystalline silicon—into sawdust. A new process developed by startup Astrowatt aims to eliminate most of this waste while making solar cells more efficient.

Conventional solar manufacturing requires sawing a block of crystalline silicon into wafers about 180 micrometers thick. As the saw cuts through the silicon, it turns almost the same amount of silicon (a layer 100 to 150 micrometers thick) into sawdust that can't typically be reused.

With the conventional process, a millimeter of silicon can produce about three solar-cell wafers. Astrowatt says it can make five or more wafers from the same amount of material by mostly replacing the sawing with a technique that allows it to peel thin layers of silicon away from a thick silicon wafer.

Astrowatt is one of several companies hoping to substantially reduce the amount of silicon needed to make solar cells. Although the price of silicon has dropped in recent years, it's still the most expensive item in solar-panel manufacturing.

The Astrowatt process begins by sawing a block of silicon into relatively thick wafers, each nearly a millimeter thick. The company then modifies the top of each wafer so that it can act as the back of a solar cell—a process that ends with depositing a layer of metal onto the wafer.

Next, the wafer is heated, causing stress within the material because the metal and silicon expand at different rates. Applying a wedge to the edge of the stressed silicon starts a crack that propagates from one edge to the other, allowing the engineers to finally peel away the metal film along with a thin, 25-micrometer layer of silicon. Crucially, the crystalline structure of silicon allows the crack to propagate evenly across the entire wafer, and the silicon is flexible, so it won't shatter as it's peeled off.
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New Capabilities of today’s Automotive Glass Equipment

Engineerblogger
Jan 30, 2012


Today’s know-how, together with new developments in control technology and machine production technologies allow to utilise automotive glass grinding and cutting machines in new ways.

This equipment with its more flexible use, can reach higher quality and/or much shorter cycle times as well as it is open for new applications.

New equipment with direct drive technology is able to preprocess glass in a higher quality and at the same time faster than in the past. Thanks to the drives the gearboxes can be eliminated, higher torque can be achieved and higher resolution encoders can be used. Eliminating the gearboxes menas eliminating the mechanical play totally. The accuracy is given by the measurement system and the performance of the drive regulator. The measurement systems can resolve down to micrometers or micronarcs for polar systems.

Using the new technology the customers do not have to decide between productivity and quality to a given price. The new controls allow to adapt the production quality to the desired level. For example a customer can start its venture in the less demanding replacement segment, where high output is critical. If he is looking for new opportunities later it is possible to reprogram the machine to the highest quality levels. The customer is able to compete on the highest quality levels which allow asking for a higher price for the manufactured product. Todays new electronic developments allow an easy and riskless adaption of parameters. The technology, accuracy and flexibility can be applied in other glass production fields like solar or architectural production as well.


Technical basis of champ’speed
Working with two cutting bridges allows to separate relief cuts and form cuts. Furthermore the customer can separate cutting and breaking if needed. Using the correct combination distributing the processes allows moving the bottleneck process in cutting and grinding from the cutting/breaking into the grinding operation. The best combination depends on the design of the end product. In most of the cases the best solution is to do the relieve cuts on the first station and the cutting and breaking on the second station. Having two independent cutting heads with one breaking ball head gives room for the very best possible combination to increase the quality and accuracy to the maximum with the lowest possible cycle time.

Figure 1: Example windscreen

Producing a form with an accuracy of 100 percent is possible but physical parameters limit the cycle time. If needed, the machine can follow the contour exactly. This will result in a very accurate glass, but takes its time. In theory, the relation between grinding speed and forward movement should be constant. To reach a constant grinding surface the speed has to be reduced at each point where the grinding spindle makes a turn or goes around an edge. This means: the smaller the radius, the lower the speed. As the grinding wheel has a diameter, the speed of its centre point has to increase, because it has to travel a much longer way than the grinding point of the glass. In an inner arc, the travelling speed has to be reduced, because otherwise the wheel would take too much glass and will get choked.

Today there are two ways, to achieve high speed and accuracy. Firstly it is possible to make the design of the form in a way that the end result will still be in specs. This means that the design is not in the middle of the tolerance field designed, but will touch the limits with working in lower tolerance bands. The achieved result is still the same (faster production cycle, in given tolerance), but the result does not depend on factors like speed or grinding wheel diameters anymore. Secondly one can do the same like in the past i.e. opening the contour error and allow bigger deviation. But with these methods the resulting form will then depend again on process parameters like speed. This method is not recommended but is very easy to do and does not require additional know-how or skill, but the production cycle improvement can still be considerable.

Figure 2: Cutting path with new equipment can increase corner speeds, improve quality and is reproducible

Additional to the improvement in cycle time due to the higher moment of the motor, a well designed grinding path can add considerable cycle time advantages. Together with using two bridge cutting and direct drive grinders, the cycle time can come from 27 seconds for a windshield down to 16 seconds, for the same design.

Higher torque and higher accuracy allow on polar machine to increase the diameter range. Not only windshields for trucks and busses but also solar glasses or other high end glass with diagonals up to 3.6m are possible to grind with accuracies below 0.1mm around the whole circumference. This accuracy can be achieved with low cost process due to low cycle times, automotive approved equipment and low cost consumables.
 

Figure 3: Trajectory speed of the grinding wheel center

Commercial applications
The investment is not much different than in the past, but the cycle times improve a lot on the same production space. This alone can justify a replacement of machines. Higher torque motors allow running the grinders faster and more accurate. Adding the possibility to use the tolerance band in improving cycle time gives more flexibility. The decision to invest in accurate or fast equipment has not to be taken anymore. The equipment can be bought and during the time of use switched by parameters to either use the machine in a mode with very low tolerances or in a mode with very high precision.

A company can start of in producing replacement glass with very high output and low cost for example and switch for other projects to OEM manufacturing parameters with high machine and process capabilities and insuring six sigma tolerances or more. The characteristic of the equipment can cater for different markets and customers by simply pushing a button or by an intelligent design. Using this way also small companies can invest and be sure, that the equipment keeps its value for all future ventures and supports future expansions. For solar glass new dimensions of accuracy can be achieved by low costs. The flexibility is there to adjust in the future to all needs of forms or accuracy. Proven process capabilities are given out of the automotive industry.

With this equipment producing changing models is possible without making test glasses. It is possible to change from one model to the next, without wasting one glass and without tweaking parameters. Change over time is dramatically reduced and lower skilled personal can handle the machines.

Figure 4: Example of a new automotive glass preprocessing equipment – champ’speed-line of Bystronic glass

Conclusion – Limitations and things to consider
Due to the fact, that the machine does what the program defines, it means that a form has to be defined 100% correctly. The machine follows the drawing exactly. The CAD-drawing must include all detail and the transition from one drawing element to the next. Transitions of elements have to be correct and tangents have to be handled with care and accuracy. This higher demand in designing capabilities might allow to reduce the capabilities of the machine operator.

About Bystronic Glass
Bystronic glass is the most competent and reliable partner for services, machinery, plants and systems in the glass processing sector. Bystronic glass supplies its well-proven machine technologies also in important areas of the photovoltaic industry. This includes preprocessing, front-end and back-end solutions. Bystronic glass is an international brand with globally operating companies that support their customers on site and through own sales and service companies. Since 1994, Bystronic glass is part of the Conzzeta AG, a renowned Swiss industrial holding company.

Source: Glass on Web


Additional Information:

• Bystronic Glass

Keeping high-performance electronics cool

Engineerblogger
Jan 30, 2012

The development of sophisticated electronics using high-performance computer chips that generate much more heat than conventional chips is challenging scientists to come up with a new type of compact cooling system to keep temperatures under control.

For the past few years, a collaborative team of engineers and other scientists from academia and industry has been investigating an advanced cooling system for electric and hybrid cars as well as computers and telecommunications systems, particularly for military use in radar, lasers, and electronics in aircraft.

The technology, which is capable of handling roughly 10 times the heat generated by conventional chips, is a device, called a vapor chamber, using tiny copper spheres and carbon nanotubes to passively wick a coolant toward hot electronics, according to Suresh V. Garimella, the R. Eugene and Susie E. Goodson Distinguished Professor in the School of Mechanical Engineering at Purdue University, West Lafayette, IN.

The current thermal solution it would replace is typically a solid heat spreader using solid aluminum and copper to conduct heat, an approach inadequate for removing large amounts of heat in powerful electronics components while maintaining low operating temperatures.

A Passive System

The vapor chamber comes in the same form factor as a solid heat spreader, says Dr. Garimella, but "The working fluid contained inside continuously undergoes [evaporation] at the heat source to more efficiently remove heat than is possible by devices that rely on conduction alone."

An advantage of vapor chambers compared to other high-performance cooling technology alternatives is that a vapor chamber is a completely passive system. According to Dr. Garimella, "It can…operate continuously without any additional pumps or valves. Such passive systems are associated with high reliability. Active cooling options which allow for high heat dissipation, such as forced liquid cooling, require an external fluid flow system including a separate pump and condenser, adding to the solution cost and size."

Much of the work is being conducted at the Industry/University Cooperative Research Center's Cooling Technologies Research Center, established by Dr. Garimella at Purdue.

Integrating Nanostructures

After publishing its findings last year about the effects of conventional sintered powder copper structures on the performance of a vapor-chamber cooling technology, the team is preparing to report on the feasibility of integrating nanostructures, specifically carbon nanotubes, into the devices to further improve performance. These results and proposed techniques for integrating carbon nanotubes into vapor chambers are expected to be published in the near future, says Dr. Garimella.

"The next step is to experimentally investigate the performance enhancement provided by integration of carbon nanotubes into vapor chambers," he says. "Another critical step in converting performance enhancements observed in the lab to actual devices is to develop engineering models and methods that allow accurate prediction of device performance for specific applications."

When the program, which is being funded by the U.S. Department of Defense's Defense Advanced Research Projects Agency, is completed at the end of this year, the hope is that there will be transition to actual applications, especially for the Department of Defense, where there is significant need, says Dr. Garimella.

Source: American Society of Mechanical Engineers (ASME)

Graphene: The Supermaterial goes superpermeable

Engineerblogger
Jan 27, 2012

Credit: University of Manchester

Wonder material graphene has revealed another of its extraordinary properties - University of Manchester researchers have found that it is superpermeable with respect to water.

Graphene is one of the wonders of the science world, with the potential to create foldaway mobile phones, wallpaper-thin lighting panels and the next generation of aircraft. The new finding at The University of Manchester gives graphene’s potential a most surprising dimension – graphene can also be used for distilling alcohol.

In a report published in Science, a team led by Professor Sir Andre Geim shows that graphene-based membranes are impermeable to all gases and liquids (vacuum-tight). However, water evaporates through them as quickly as if the membranes were not there at all.

This newly-found property can now be added to the already long list of superlatives describing graphene. It is the thinnest known material in the universe and the strongest ever measured. It conducts electricity and heat better than any other material. It is the stiffest one too and, at the same time, it is the most ductile. Demonstrating its remarkable properties won University of Manchester academics the Nobel Prize in Physics in 2010.

Now the University of Manchester scientists have studied membranes from a chemical derivative of graphene called graphene oxide. Graphene oxide is the same graphene sheet but it is randomly covered with other molecules such as hydroxyl groups OH-. Graphene oxide sheets stack on top of each other and form a laminate.

The researchers prepared such laminates that were hundreds times thinner than a human hair but remained strong, flexible and were easy to handle.

When a metal container was sealed with such a film, even the most sensitive equipment was unable to detect air or any other gas, including helium, to leak through.

It came as a complete surprise that, when the researchers tried the same with ordinary water, they found that it evaporates without noticing the graphene seal. Water molecules diffused through the graphene-oxide membranes with such a great speed that the evaporation rate was the same independently whether the container was sealed or completely open.

Dr Rahul Nair, who was leading the experimental work, offers the following explanation: “Graphene oxide sheets arrange in such a way that between them there is room for exactly one layer of water molecules. They arrange themselves in one molecule thick sheets of ice which slide along the graphene surface with practically no friction.

“If another atom or molecule tries the same trick, it finds that graphene capillaries either shrink in low humidity or get clogged with water molecules.”

“Helium gas is hard to stop. It slowly leaks even through a millimetre -thick window glass but our ultra-thin films completely block it. At the same time, water evaporates through them unimpeded. Materials cannot behave any stranger,” comments Professor Geim. “You cannot help wondering what else graphene has in store for us”.

“This unique property can be used in situations where one needs to remove water from a mixture or a container, while keeping in all the other ingredients”, says Dr Irina Grigorieva who also participated in the research.

“Just for a laugh, we sealed a bottle of vodka with our membranes and found that the distilled solution became stronger and stronger with time. Neither of us drinks vodka but it was great fun to do the experiment”, adds Dr Nair.

The Manchester researchers report this experiment in their Science paper, too, but they say they do not envisage use of graphene in distilleries, nor offer any immediate ideas for applications.

However, Professor Geim adds ‘The properties are so unusual that it is hard to imagine that they cannot find some use in the design of filtration, separation or barrier membranes and for selective removal of water’.

Source: The University of Manchester

Additional Information:

• The paper, Unimpeded Permeation of Water Through Helium-Leak–Tight Graphene-Based Membranes, by R. Nair, H. Wu, P. Jayaram, V. Grigorieva and A. Geim, embargoed by Science until 7pm GMT on Thursday 26th January 2012, is available from the Press Office.

Engineer wants to ‘sculpt’ more powerful electric motors and generators

Engineerblogger
Jan 27, 2012

Iowa State University's Dionysios Aliprantis is working to improve the performance of electric motors.  Photo by Bob Elbert

Dionysios Aliprantis took up an imaginary hammer and chisel and pounded away at the air.

"Think of the ancient Greeks and their sculptures," said the Iowa State University assistant professor of electrical and computer engineering.

Now apply the idea of a sculptor precisely chipping away at stone to the electric motors that run our machines and generate our electricity. Aliprantis is working to develop computer modeling technology that will show engineers how to chip away at the surfaces of electric motors to create new designs and shapes that can increase power generation.

"The goal is to get more power out of the same size motor," he said. "Or, that could mean getting the same power with a smaller motor."

Aliprantis is quick to say he's not looking for a huge improvement in a motor's performance.

"I'm looking for a little bit of increase, maybe 5 percent or 1 percent," he said. "But multiply that number by the number of hybrid cars, let's say, and you could get savings in the billions of dollars. The potential here could be huge."

Aliprantis' project is supported by a five-year, $400,000 grant from the National Science Foundation's Faculty Early Career Development Program. The grants support junior faculty identified as teacher-scholars through outstanding research, excellent education and the integration of education and research.

Assisting with the motor design project is Yanni Li, a doctoral student in electrical and computer engineering.

Aliprantis and Li want to take advantage of the fact that most electric motors and generators operate in just one direction - in most applications there's no real need for them to go into reverse. The motors, however, have long been designed to offer equal performance no matter which way they're rotating.

And so the engineers are exploring how electric motors can be improved by optimizing performance in a preferred direction of rotation. To do that, they've written a computer modeling program that incrementally changes the design of the motors - just like a sculptor chipping away - and calculates when the surface shape is just right.

The teeth that hold coils of wire within an electric motor, for example, have typically been built with a symmetrical shape that maintains performance in either direction. By making the teeth asymmetrical, the engineers hope the motor can pick up some power when rotating in the preferred direction.

"We are trying to develop a systematic way of getting to the right shape," Aliprantis said. "This idea is very simple, but motors are still being designed using techniques that are essentially one hundred years old."

Aliprantis is also busy with other projects to improve electric motors, advance alternative energy systems and improve engineering education:

• Another project is aiming to improve the models used to predict the dynamic performance of electric motors as engineers experiment with different power electronics and control technologies. The idea is to develop more sophisticated control systems that capture more of a motor's performance characteristics. The project is supported by Iowa State's department of electrical and computer engineering and includes Yuanzhen Xu, a master's student in electrical and computer engineering.

• Aliprantis is also collecting data on how much solar energy is available throughout a day. The idea is to improve power forecasts by developing better models of cloud cover. That would help utilities make better estimates of the power they can expect from solar panels on a given day. Chengrui Cai, a doctoral student in electrical and computer engineering, is assisting with the project.

• Aliprantis is part of an Iowa State faculty team that's developing a new, multidisciplinary doctoral program in Wind Energy Science, Engineering and Policy. He's also using a National Science Foundation grant to work with Purdue University faculty to improve undergraduate education in power electronics and motor drives by modernizing student lab equipment and course content.

Because electric motors are all around us - in vehicles, wind turbines, power plants and all kinds of machinery - Aliprantis said finding new ways to improve their performance can make a real difference in the development of sustainable energy resources.

Source:  Iowa State University

Heavy going without lightweight materials

Engineerblogger
Jan 27, 2012

Source: iStock-Foto

Automobiles made of steel suffer from a weight problem, and racing yachts made of steel have no chance of winning regattas. Fiber-reinforced composites offer an alternative which has spread rapidly in the transport industry. Empa's offers an overview of the current situation and a preview of future developments.

Those who take an interest in innovation in the automobile industry might have thought that BMW and VW would have a head start in the use of carbon fiber structures in their vehicles. Last year both companies purchased shares in the supplier SGL Carbon. The competition hasn't been asleep, though, and companies like Daimler AG are hard on their heels. The car manufacturer based in Stuttgart has entered into a joint-venture with Toray Industries, the carbon fiber producer. Jan Krueger, of Daimler’s Research and Advanced Engineering division, is convinced that the victorious march of fiber-reinforced composite materials will continue unabated. The advantages are easy to see: the new materials are lightweight, with good crash properties and noise and vibration reducing characteristics. Daimler has accumulated a lot of experience in lightweight construction techniques using fiber-reinforced composites with its Mercedes SLR McLaren Supersport car. Two and a half thousand examples of the noble racing car have come off the conveyor belt, and in the meantime the new technologies involved have fed into the mass production lines. From summer 2012 the boot lid of the SL 63 AMG Sport Coupé will be made using fiber composites. Already 140,000 front axle leaf springs are manufactured every year for the Mercedes Sprinter using composite materials, and every second seat heating system built into cars made in Stuttgart boasts heating elements made of carbon fiber.

Crash simulation
Peter Fritzsche of the University of Applied Sciences of Northwestern Switzerland reported on the simulation of break and crash tests with fiber-reinforced composites materials. Although the complex and nonlinear behavior of these materials often produces surprising results, computer simulation of the characteristics has already enabled considerable progress to be made. The more accurately the plastic deformation of the composites can be modeled, the more precisely can components made of composites be designed for a specific application.


Mass production at minimum cost
The views of a large manufacturer with thousands of employees worldwide were presented by Wenzel Krause of Autoneum, formerly the automotive division of the Rieter company. Autoneum supplies car manufacturers in North and South America, Europe and Asia with carbon fiber composite components which are used in the engine wells, underbodies, passenger compartments and boots of their vehicles. In doing so, Autoneum uses and delivers some one hundred thousand tonnes of the material annually. High stiffness and impact resistance are characteristics particularly demanded of materials used for underbody protection, naturally at the lowest possible cost. The company utilizes various production methods to manufacture components with exactly the required properties. Glass fibers cut to various lengths are used to reinforce the components in specific ways. The highest possible degree of automation is absolutely essential in mass production applications.

The next Alinghi
Carbon fiber-reinforced composite materials have already been used for some time in special high-value applications, such as that field of non-plus ultra yacht construction, the America's Cup. Andreas Winistoerfer with his company CarboLink GmbH (and Empa spin-off) designs stays and ropes for these yachts. Money is of secondary importance, but if a component should fail this is seen all over the world by millions of viewers. Winistoerfer has been in this demanding business for 10 years now. In addition to items for yachts, CarboLink also supplies the crane manufacturer Liebherr with high-tech guys of carbon fiber. The industrial partner profits from a 50 to 70 per cent weight reduction and, thanks to improved fatigue characteristics, a lifetime of up to 15 times longer for the carbon fiber component compared to that of steel.


Fibers with liquid content
Empa’s (Rheocore) project is dedicated to creating improved tailor-made properties of composites materials by spinning fibers which contain branched channels of liquid. The aim is to create fibers which are flexible when bent slowly but react stiffly to rapidly acting forces. This effect could be used to create a new type of protective clothing which would be more comfortable to wear than anything available today. However the production of these liquid chambers in the fiber is anything but trivial, explained Rudolf Hufenus of Empa’s Advanced Fibers Laboratory. In the meantime the project team has established the mathematical foundations of the effect and completed modeling trials. The next step is the manufacture of a first prototype of the spinning nozzle.


Source: Swiss Federal Laboratories for Materials Science and Technology(EPMA)

New uses for diesel by-products

Engineerblogger
Jan 27, 2012

A new catalytic process discovered by the Cardiff Catalysis Institute could unleash a range of useful new by-products from diesel fuel production.

More sustainable production of sulphur-free diesel from natural gas and biomass is increasing. However the by-products, hydrocarbons like decane and other low value alkanes have little practical use.

Now a discovery by the Institute, part of the School of Chemistry, has found a potential route for upgrading these by-products into more useful chemicals.

In the past, synthetic reactions starting from alkanes like decane have been fraught with difficulty. They tend either to over-dehydrogenate or to combust, depending on whether oxygen is present in the reaction. Now a Cardiff Catalysis Institute team has reported the use of a mixed-metal catalyst to convert decane to a range of oxygenated aromatics.

The breakthrough, published in Nature Chemistry, came when the team fed a gas mixture of decane and air through an iron molybdate catalyst. At higher temperatures, the reaction formed water and decene, which is used in the production of detergents. At lower temperatures, however, the reaction took a different route to create oxygenated aromatic molecules. These included phthalic anhydride, used in the dyeing industry, and coumarin which helps in the production of anti-coagulant drugs.

Professor Stan Golunski, a member of the Institute team behind the discovery said: "This discovery breaks new ground as it implies the involvement of oxygen that has not yet made the full transition from its molecular form to its ionic form. This overturns a widely-held view that this type of oxygen was too reactive to form anything other than carbon monoxide and carbon dioxide in reactions with hydrocarbons."

"While the increased production of sulphur-free diesel has been a positive move, the glut of low value by-products will become a problem. We hope our new process will lead to less waste and the creation of more useful chemicals for a range of industries."

Source: Cardiff University

Novel Materials for Hydrogen Storage

Engineerblogger
Jan 27, 2012

Berkeley Lab scientist Jeffrey Long co-leads a project to develop novel materials for hydrogen storage. (Credit: Roy Kaltschmidt/Berkeley Lab)

The biggest challenge with hydrogen-powered fuel cells lies in the storage of hydrogen: how to store enough of it, in a safe and cost-effective manner, to power a vehicle for 300 miles? Lawrence Berkeley National Laboratory (Berkeley Lab) is aiming to solve this problem by synthesizing novel materials with high hydrogen adsorption capacities.

The U.S. Department of Energy recently awarded Berkeley Lab a three-year, $2.1 million grant for the project, which will also include contributions by the National Institute of Standards and Technology (NIST) and General Motors (GM). The grant was part of more than $7 million awarded by DOE last month for hydrogen storage technologies in fuel cell electric vehicles.

“We’re working on materials called metal-organic frameworks to increase the capacity of hydrogen gas in a pressure cylinder, which would be the fuel tank,” said Jeffrey Long, a Berkeley Lab scientist who co-leads the project along with Berkeley Lab chemist Martin Head-Gordon. “With these materials, we’re working on storing the hydrogen without the use of very high pressures, which will be safer and also more efficient without the significant compression energy losses.”

Metal-organic frameworks (MOFs) are three-dimensional sponge-like framework structures that are composed primarily of carbon atoms and are extremely lightweight. “What’s very special about these materials is that you can use synthetic chemistry to modify the surfaces within the materials and make it attractive for hydrogen to stick on the surface,” Long explained.

Separately, Long is also using MOFs in a carbon capture project, in which the material would selectively absorb carbon dioxide over nitrogen. For the fuel cell project, the trick lies not in getting the MOF to select hydrogen out of a mixture but to store as much hydrogen as possible.

Currently, vehicles using hydrogen fuel cells can achieve a range of close to 300 miles—but only if the hydrogen is stored at extremely high pressures (600 to 700 bar), which is expensive and potentially unsafe. It is also energy intensive to pressurize the hydrogen.

So far Long has succeeded in more than doubling hydrogen capacity, but only at very low temperatures (around 77 Kelvin, or -321 Fahrenheit). “It’s still very much basic research on how to create revolutionary new materials that would boost the capacity by a factor of four or five at room temperature,” he said. “We have an idea of what kinds of frameworks we might make to do this.”

Long’s approach is to create frameworks with lightweight metal sites on the surface, making it attractive for hydrogen molecules to bind to the sites. “Our approach has been to make some of the first metal-organic frameworks that have exposed metal cations on the surface,” he said. “Now we need to figure out ways of synthesizing the materials so that instead of one hydrogen molecule we can get two or three or even four hydrogen molecules per metal site. Nobody’s done that.”

This is where Head-Gordon, a computational chemist, comes in. He will work on theoretical understanding of MOFs so that he can try to predict their hydrogen storage properties and then instruct Long’s team as to what kind of material to synthesize. “He can do calculations on a lot of different target structures and say, here’s the best one for you guys to spend time trying to make, because synthetic chemistry is very cost and labor intensive,” Long said.

The scientist at GM will aid in providing accurate high-pressure measurements. The NIST scientist is an expert in neutron diffraction and neutron spectroscopy, which will allow Long and his team to pinpoint where exactly the hydrogen is going and verify that it is binding to the metals.

Source: Lawrence Berkeley National Laboratory (Berkeley Lab)

Waste not: Cooking oil great energy source

Engineerblogger
Jan 27, 2012

At one time, Richard Varano, the proprietor of Billy’s Chowder House in Wells, ME, contracted with a local waste disposal firm to haul away his used cooking oil, paying $65 a month for the service.

These days, Varano puts the oil into a device called the Vegawatt, which burns the waste product and sends the heat back into the restaurant to produce hot water for use in the dishwashers and other kitchen facilities. “I’m saving the $65 in waste removal fees, and on top of that about $500 each month in energy costs,” says Varano.

And he is helping the environment. That’s because vegetable oil, a completely renewable biofuel, burns more cleanly than fossil fuel while producing no adverse impact on global warming and supporting worldwide initiatives to reduce carbon-based energy generation.

Beginnings in Transportation

The use of vegetable oil as a fuel dates back to 1898, when the German inventor Rudolph Diesel developed a new type of internal combustion engine that used oil derived from peanuts. Vegetable oil would continue to be used in diesel engines in the early years following the turn of the century.

A hundred years later, vegetable oil is attracting a renewed interest, with the focus shifting from transportation to stationary power generation. According to the University of Minnesota, the U.S. produces roughly 2.7 billion pounds of yellow and brown grease a year, the byproducts of restaurant kitchens and various industrial processes. For proponents of alternative energy, this grease is a precious commodity, an available fuel source that can run a diesel engine to produce heat and electrical generation.

Developmental programs have been underway to optimize processed waste vegetable oil and test its efficiency and practicality in power generation. The Biofuels Power Corp. in Spring, TX, recently announced plans to come online with a 9-megawatt generator that runs on refined waste vegetable oils. The plan is for the generator to be connected to a gas turbine to provide grid power to homes and business in the Houston area.
But it is not large-scale municipal power generation that is creating a market for biodiesel. Plant-derived fuel sources, energy experts believe, can contribute only about 1-2% of the energy needs in the United States.

 

Image courtesy of Vegawatt.

Market Niche

Where vegetable oil is finding a market is in distributed generation applications, in which a power system is configured to provide supplemental heat or electricity to a single home or business. Restaurants, with their continuous supply of waste oil from food preparation, are an ideal market, according to James Peret, founder and chief executive officer of Owl Power Company, maker of the Vegawatt systems.

Richard Varano purchased a 12-kW Vegawatt from Owl. Each year, the chowder house produces about 5,000 gallons of used vegetable oil from its kitchen deep fryers. Once the cooking life of the oil is depleted, Varano’s staff deposits the waste product into storage tanks, from where it is pumped into the Vegawatt. There, a diesel engine consumes the vegetable oil to produce hot water and electricity.

Varano estimates that the system provides about 25% of the restaurant’s electricity and 80% of the hot water.

Owl, located in Boylston, MA, has sold 21 systems since the company started in 2007. Larry Fogarty, the owner of Fogarty’s bakery and restaurant in South Berwick, ME, purchased a 5-kW system from Owl in July 2011 to provide electricity and hot water. “A friend and engineer from the local area, who used vegetable oil in automobile engines, encouraged me to consider the generator,” says Fogarty. “The system has performed well and I’m thinking about expanding its capabilities.”

At $32,000, the unit was a significant business expense; however, Fogarty received a grant from the state of Maine. Peret estimates that a restaurant with an installed Vegawatt can realize a 25-50% reduction in energy costs each year, which can justify the up-front cost of the system and help a client recoup the investment.

The increasing interest in using vegetable oil as fuel, coupled with worldwide initiatives to reduce carbon dioxide emissions, have spawned a global industry. Large and small companies from the U.S. to Spain and from Germany to China design and manufacture vegetable oil generators and peripheral equipment like diesel conversion kits and oil filtration systems. Organic Mechanic distributes an oil press along with a line of generators.

“Farmers can press oil from avocado, soybean, sunflower, or other types of plants and use it to fuel tractors and other farm equipment,” says Christopher Kindig, founder of the six-year old Organic Mechanic.

Paper at 2011 ASME Congress

The primary obstacle to a more widespread use of vegetable oil is availability. Three researchers at the University of Roma in Italy have carried out a comprehensive analysis of power generation using palm oil in a marine diesel, assessing a range of economic and technology factors. Their system performed acceptably in the areas of emissions and heat value. The problem was the lack of biofuel availability, which forced the researchers to import other types of fuel to operate the system, driving up costs.

“Our results show how the fuel cost can decisively affect the feasibility of the power plant,” explained Roberto Capata, a member of the research team, who lectured at the 2011 ASME International Mechanical Engineering Congress and Exposition in Denver, CO. “This highlights the special attention to be paid in searching for suppliers that are able to ensure affordable and stable oil purchase conditions over a long period.”

In the meantime, vegetable oil enjoys success in the retail power market, where restaurant owners, farmers, and other users are contributing to a clean environment—and saving money in the process.

Source:  American Society of Mechanical Engineers (ASME)

MIT faculty see promise in American manufacturing

MIT News
Jan 25, 2012

Graphic: Christine Daniloff

As the United States seeks to reinvigorate its job market and move past economic recession, MIT News examines manufacturing’s role in America’s economic future through this series on work at the Institute around manufacturing.

Not long ago, MIT political scientist Suzanne Berger was visiting a factory in western Massachusetts, a place that produces the plastic jugs you find in grocery stores. As she saw on the factory floor, the company has developed an innovative automation system that has increased its business: Between 2004 and 2008, its revenues doubled, and its workforce did, too. Moreover, the firm has found a logical niche: Since plastic jugs are both bulky and inexpensive, it’s not economical to produce them overseas and ship them to the United States, simply to fill them with, say, milk or syrup.

“Is this just an odd little story?” Berger asks. “Actually, no.” While the decline of American manufacturing has been widely trumpeted — manufacturing jobs in the United States have dropped from 20 million in 1979 to about 12 million today — conglomerates such as Procter & Gamble and high-tech firms such as Dow Corning have kept significant amounts of manufacturing in the country. Moreover, 3,500 manufacturing companies across the United States — not just the jug-making firm in Massachusetts — doubled their revenues between 2004 and 2008. With that in mind, Berger asks, “How can we imagine enabling these firms to branch out into more innovative activities as well?”

That is the kind of problem Berger and 19 of her faculty colleagues at MIT are now studying as part of a two-year Institute-wide research project called Production in the Innovation Economy (PIE), which is focused on renewing American manufacturing. The guiding premise of PIE is that the United States still produces a great deal of promising basic research and technological innovation; what is needed is a better sense of how to translate those advances into economic growth and new jobs.

As Berger puts it, “The single most important question in the study is: What kind of manufacturing do we need in order to get full value out of our innovation strengths?”

That question is currently at the forefront of MIT’s concerns as well. Institute President Susan Hockfield is serving as a co-chair of the steering committee of President Barack Obama’s Advanced Manufacturing Partnership (AMP), which in June will give policy recommendations to the White House about renewing American manufacturing. PIE is not a subset of AMP, but arises from similar concerns about applying technology in the national interest.
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Smallest-Ever Nanotube Transistors Outperform Silicon

Technology Review
Jan 26, 2012

Nano gate: A conceptual illustration shows a nanotube positioned between the source and drain of a transistor. Credit: IBM

The smallest carbon-nanotube transistor ever made, a nine-nanometer device, performs better than any other transistor has at this size.

For over a decade, researchers have promised that carbon nanotubes, with their superior electrical properties, would make for better transistors at ever-tinier sizes, but that claim hadn't been tested in the lab at these extremes. Researchers at IBM who made the nanotube transistors say this is the first experimental evidence that any material is a viable potential replacement for silicon at a size smaller than 10 nanometers.

"The results really highlight the value of nanotubes in the most sophisticated type of transistors," says John Rogers, professor of materials science at the University of Illinois at Urbana-Champaign. "They suggest, very clearly, that nanotubes have the potential for doing something truly competitive with, or complementary to, silicon."

The shrinkage of silicon transistors over the past several decades has reduced the cost of electronics and led to more processing power with less energy consumption. But the downsizing of silicon electronics might hit a roadblock at around 10 nanometers, says Aaron Franklin, a researcher at the IBM Watson Research Center in Yorktown Heights, New York. "We are now reaching physical limits," he says. As transistors are made smaller, it gets more difficult to control how electrons move through the silicon channel to turn the transistor on and off. Faced with this unruly, power-draining behavior, Intel announced last year that it would switch to a new, three-dimensional transistor design for its 22-nanometer generation of chips. Other companies are working on so-called ultrathin body transistors. No matter how it's shaped, though, silicon is silicon, and dealing with it at extremely small sizes presents problems even in these new transistor designs.

Many materials have been hyped as a potential replacement for silicon, including carbon nanotubes. That material and others have shown promise in larger transistors, but until now, no one had demonstrated a carbon-nanotube transistor smaller than 10 nanometers. "If nanotubes can't go much further than silicon, then working on them is a waste of time," says Franklin. "We've made nanotube transistors at aggressively scaled dimensions, and shown they are tremendously better than the best silicon devices."

To test how the size of a nanotube transistor affected its performance, Franklin's group made multiple transistors of different sizes along a single nanotube. This enabled them to control for any variations that might occur from nanotube to nanotube. First, they had to lay down a very thin layer of insulating material for the nanotube to sit on. And they developed a two-step process for adding electrical gates to the nanotube without damaging it. These techniques are by no means ready for manufacturing, but they enabled the IBM group to make the first nanotube devices smaller than 10 nanometers to test in the lab. The work is described online in the journal Nano Letters.
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Sensor Sensibility - better protection for concrete coastal structures

Engineerblogger
Jan 26, 2012

The research will dramatically improve the ability to spot early warning signs of corrosion in concrete. Credit:

Innovative sensors have been developed that will dramatically improve the ability to spot early warning signs of corrosion in concrete.

More resilient and much longer lasting than traditional corrosion sensors they will make monitoring the safety of structures such as bridges and vital coastal defences much more effective.

The carbon steel bars used to reinforce submerged concrete in tidal zone areas are at particular risk of corrosion caused by wet conditions (see note).

The breakthrough has been made by researchers based at City University London and Queen's University Belfast following several research projects funded by the Engineering and Physical Sciences Research Council (EPSRC).

Because the sensors can withstand long-term placement within concrete - unlike any equivalent sensors currently available - they can constantly monitor conditions, enabling a warning to be sent when conditions for corrosion threshold have been crossed.

Thanks to an internet connection, the notification can be sent in the form of an email or text to the structure's maintenance team.

A trio of novel, robust probes is at the heart of the team's work: one that monitors temperature, one for humidity while the other senses chloride and pH levels. Changes in these factors indicate the onset of the potentially destructive corrosion. Within the probes are advanced optical sensors specifically designed and built for this project in City's laboratories. These have been patented for potential commercial exploitation.

Tong Sun, Professor of Sensor Engineering at City and Principal Investigator on the project says: "Key to this successful prototype is our monitoring the variation of the sensor signals of a sample as an indicator of corrosion levels. This means we can use optical sensors made of polymer, which is much more resistant to the high alkaline environments of these structures than sensors currently on the market."

Traditional optical corrosion sensors have only a limited lifetime, usually of several weeks, because of the corrosive alkaline levels within concrete. The new sensors are expected to last for several years, with proper protection, even where pH levels are higher than 12. For comparison, domestic bleach has a pH value of between 12 and 13.

"Our design means several probes can be installed semi-permanently in a structure and then connected to a computer data logger, which will constantly collect readings. This can be left until the readings indicate conditions have changed enough to warrant a full investigation. Remedial work will be simpler, cheaper and more effective at this stage, rather than waiting until there is visible damage, such as parts of the concrete coming away," said Professor Sun.

Source: The Engineering and Physical Sciences Research Council (EPSRC)

Why 3-D Printing Will Go the Way of Virtual Reality

Engineerblogger
Jan 26, 2012

CNC toaster / 2D thermal printer cc Windell Oskay

There is a species of magical thinking practiced by geeks whose experience is computers and electronics—realms of infinite possibility that are purposely constrained from the messiness of the physical world—that is typical of Singularitarianism, mid-90s missives about the promise of virtual reality, and now, 3-D printing.

As 3-D printers come within reach of the hobbyist—$1,100 for MakerBot's Thing-O-Matic—and The Pirate Bay declares "physibles" the next frontier of piracy, I'm seeing usually level-headed thinkers like Clive Thompson and Tim Maly declare that the end of shipping is here and we should all start boning up on Cory Doctorow's science fiction fantasies of a world in which any object can be rapidly synthesized with a little bit of energy and raw materials.

This isn't just premature, it's absurd. 3-D printing, like VR before it, is one of those technologies that suggest a trend of long and steep adoption driven by rapid advances on the systems we have now. And granted, some of what's going on at present is pretty cool—whether it's in rapid prototyping, solid-fuel rockets, bio-assembly or just giant plastic showpieces.

But the notion that 3-D printing will on any reasonable time scale become a "mature" technology that can reproduce all the goods on which we rely is to engage in a complete denial of the complexities of modern manufacturing, and, more to the point, the challenges of working with matter.

Let's start with the mechanism. Most 3-D printers lay down thin layers of extruded plastic. That's great for creating cheap plastic toys with a limited spatial resolution. But printing your Mii or customizing an iPhone case isn't the same thing as firing ceramics in a kiln or smelting metal or mixing lime with sand at high temperatures to produce glass—unless you'd like everything that's currently made from those substances to be replaced with plastic, and there are countless environmental, health, and durability reasons you don't.

Advocates of 3-D printing also neglect entirely the fact that so much of what we use continues to be made out of natural substances, and for good reason. By any number of measures, wood is pound-for-pound stronger than steel, and the move toward natural products for packaging suggests that the strength and affordability of paper, bamboo and even mushrooms mean that in the future there will be more and not less of all of these.

The desire for 3-D printing to take over from traditional manufacturing needs to be recognized for what it is: an ideology. Getting all of our goods from a box in the corner of our home has attractive implications, from mass customization to "the end of consumerism." With stakes like those, who wouldn't want to be a true believer?

Hype is inevitably followed by some level of backlash, or at least disinterest, and it would be a shame for 3-D printing to head into a too-deep trough of the Gartner hype cycle. There will be plenty of interesting applications for 3-D printing, but I'll bet the ones that will have the biggest impact will be within traditional factories, where rapid prototyping is already having a huge impact.

Source: Technology Review