Design News is part of the Informa Markets Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Software charts troubled waters

Software charts troubled waters

It is difficult to even estimate the cost of progress. According to Barry Burgan, coordinator of the Environmental Protection Agency's National Water Quality Inventory, Washington, D.C., only a fraction of the rivers, lakes, wetlands, and ground water are sampled by the States. The EPA suggests that non-point sources of pollution, which by definition are diffuse or otherwise difficult to trace, are responsible for 50% of America's current water-pollution problems.

The most recent National Water Quality Report, issued in 1994, points out: "We know even less about the condition of our coastal waters than we do about our estuarine or inland waters...Only 6% of the Nation's estimated 56,121 miles of ocean coastline [have been assessed]...Data on pollutants and sources of pollution are too sparse to be included in this report."

In short, we have no idea how polluted our water really is.

However, the well-publicized clean-ups of Lake Erie, the Hudson River, and Massachusetts Bay give evidence to the assertion that what was done can be undone. According to Richard Signell, an oceanographer at the Woods Hole Field Center, Woods Hole, MA, run by the U.S. Geological Survey (USGS): "Modeling is the key to understanding. Before we can attack the threats posed by water pollution, we have to understand the mechanisms by which pollution is transported and diluted in water."

Signell has participated in a number of programs funded by the USGS designed to develop regional water models for use by government agencies, city planners, businesses, and as the basis for future research. The primary software tools used to construct these simulations are the Estuarine, Coastal, and Ocean Model, semi-implicit (ECOM-si) and the Hindcasting Shallow Water Waves (HISWA) prediction model.

Performing multiple runs is the key to accurate modeling with ECOM-si. Models developed by the USGS seem crude by mechanical engineering standards: The Massachusetts Bay models typically have 70 x 70 grid points and 15 levels while the most ambitious Gulf of Maine models have grids of 103 x 151 points and 19 levels. However, the time domains used quickly suck down processor power. "We often calculate 10 minute time steps for periods of years," Signell says. "And we do it repeatedly."

There are so many variables in a coastal fluid system, it is not obvious which ones are having a significant impact on pollution. For example, in order to accurately model Massachusetts Bay, the analysts must take into account the topology of the ocean floor and sedimentation, prevailing currents on a monthly basis, seasonal wind effects, outflow from rivers, stratification of the water column, and temperature. With ESOM-si, investigators can "turn off" rivers, winds, or particular currents on a given run.

Verification is a vital activity for accurate modeling. Engineers crash cars to verify predictions made with analysis codes, and oceanographers go out in boats to ping away with sonar and throw sensors in the water. Between 1990 and 91, the National Estuary Program of the Environmental Protection Agency sponsored a major field study of Massachusetts Bay.

A series of 25 current-measuring instruments were moored at nine locations throughout the bay. The instruments, developed by EG&G Inc., Wellesley, MA, posed vanes at right angles for measuring current velocities. EG&G offers a wide variety of environmental monitoring and remediation products and services.

In addition, the EPA survey acoustic doppler current profilers developed by what is now Sontek, San Diego, CA, were placed on the bottom. There, the devices shot sonar pulses upward and measured densities of sediments and organisms in the water from returns.

The Mass mess. According to Signell, the data gained from the EPA survey has proven invaluable in verifying regional pollution transport models. A case in point is the ongoing Boston Harbor Project, designed to reduce concentrations of sewage near the city.

Massachusetts plans to move the point where treated sewage (sanitized as "effluent" in official nomenclature) is discharged from the mouth of the Boston Harbor to a battery of diffusers nine miles offshore. There, it is argued, the forces of nature will dilute the effluent more effectively than in the estuarine environment of the harbor. Also, the expanse of Massachusetts Bay, cradled by Cape Cod, is expected to provide an effective depositional trap for fine-grained sediments.

However, the open flank of Massachusetts Bay is dominated by the Stellwagen Bank National Marine Sanctuary. This glacially formed underwater plateau supports zooplankton in profusion and thus serves as a feeding ground for many species, including humpback whales, basking sharks, endangered sea turtles, and shore birds of all descriptions. In addition, the Sanctuary provides an important resource for commercial fishing. It would not do for Boston to befoul an environmentally sensitive region while cleaning up its act.

According to Signell, simulations of both the current and proposed discharge sites showed that the latter resulted in a much more rapid dilution of effluent. Furthermore, the Gulf of Maine current and northeast wind patterns tend to move effluent south and west, away from the Stellwagen Bank. Signell reports that these contaminant transport studies were influential in defeating a court challenge to the project.

Similar techniques to those applied to modeling coastal waters are used for inland bodies as well. The USGS is using ECOM-si to develop models of Lake Ponchartrain, near New Orleans. HydroQual Inc., Mahwah, NJ, uses software and on-site analysis to develop water-quality models and pollution amelioration strategies in communities all over the U.S.

According to Kevin Keane, HydroQual's marketing director, the company's scientists and engineers have developed many models for eutrophication, sediment transport, contaminant fate and transport, and food-chain/bioaccumulation. "These models allow for a quantitative evaluation of potential impacts and for an assessment of the use of various management and/or remedial alternatives," Keane says. For standing bodies of water, the best (and often the only) pollution management option is prevention.


HydroQual Applications of the ECOM-si models

The code developed by HydroQual consultant Alan Blumberg has been instrumental in many pollution control activities around the country. Here are a few highlights:

The EPA, in conjunction with the States of New York and Connecticut, requested a study into the causes of low-dissolved oxygen in Long Island Sound. Model results have been used to propose nitrogen-reduction targets for waste treatment plants discharging into the Sound and immediate vicinity.

  • The EPA and the U.S. Army Corps of Engineers have been using sediment models of Chesapeake Bay to plan dredging strategies. The model, in conjunction with others, is being used to develop a comprehensive management plan for the Bay that mandates reductions in point and non-point pollutant discharges.

  • A model of sediment transport was developed for the Watts Bar Reservoir in Tennessee in order to evaluate how the activities of Oak Ridge National Labs have contributed to elevating PCB concentrations in fish.

  • Recent copper and mercury data from New York Harbor indicate metals criteria are being exceeded. Modeling showed point sources were responsible, and the EPA is revising its discharge permits so ambient criteria are achieved.

Hot products

Hot products

Fasteners offer strength without heat treatment

MetCamTM fasteners are made from a low-carbon steel that hardens during the cold-forming process, enabling property class 8.8 characteristics without heat treatment. Property class 9.8 characteristics are achieved through a short heat-aging process. Initial testing shows the MetCam fasteners have a fatigue endurance limit 100% greater than heat-treated fasteners. In addition, they can reduce susceptibility to hydrogen-assisted failure. MetCam fasteners reduce manufacturing time and eliminate the cost of heat treatment and the bending of long parts that can occur during heat treating operations.The fasteners are available in thread sizes M5 through M12 and lengths from 20 through 150 mm. Camcar Textron, FAX: (815) 961-5345.

Studs install in thin sheets

PEM(R) Type FH4TM flush-head studs provide strong threads in stainless-steel sheets as thin as 0.040 inch (1 mm). Upon installation, the studs create a flush-head assembly and lock securely with high torque-out and push-out resistances. Made from 400 Series stainless steel, the studs are suited for use in stainless sheets with a hardness of HRB 92 or less. To install, place the studs in punched or drilled holes in the sheet and squeeze into place with any standard press. Type FH4 studs are an alternative to weld studs and are available in standard thread sizes of #4-40, #6-32, #8-32, and #10-32; and in millimeter thread sizes M3, M4, and M5. Lengths range from 0.250 inch to 1.5 inches and 6 to 35 mm. Penn Engineering & Manufacturing Corp., e-mail: pem@pemnet.com, http://www.pemnet.com, FAX: (215) 766-0143.

Latch detents in two positions

An ergonomically designed handle latch detents in full open and closed positions. It provides single- or three-point latching, making it suitable to drive the company's Rod Roller Compression Latch System. The latch is available with a T- or L-shaped handle, in either a bright chrome plate or a black powder-coat finish. Other choices include locking or non-locking, and left- or right-hand latch operation. Southco Inc., FAX: (610) 358-6314.

Adhesive bonds lightweight materials

The 3M Spray-Bond Heat-Applied Adhesive System is a neat alternative to aerosols as well as contact and solvent-based adhesives for bonding foam and other lightweight materials. Users spray a pattern of 100% solids adhesive only where needed, thus minimizing overspray, saving on clean up, and protecting the work area. Spray-Bond adhesive need only be applied to one surface for an immediate bond. If more open time is required, users have up to five minutes with a two-surface application. This one-part adhesive eliminates mixing and catalyzed systems and comes with a self-contained, hand-held applicator. A 1.5-mm nozzle is standard; 0.8- and 1.2-mm nozzles and bead tip kits are optional. 3M, Industrial Tape and Specialties Div., ph: (800) 362-3550.

Screws offer electrical insulation

Socket-Drive Polytops combine the mechanical strength of steel with the electrical insulating and dielectric properties of polymers. The fasteners comprise conventional steel screws with molded bihexagonal socket drive heads. The head's polymer has a volume resistivity of 1014 cm and a surface resistivity in excess of 1014. All common screw types are available, including self-tapping, self-drilling, thread-forming, and machine-screw styles, in either zinc-plated or 304 stainless steel. Lengths range from 1/2 inch to 4 inches. The screws come in 6, 8, 10, and 12 gauge, with machine screws available in 1/4-inch diameter. Metric sizes are also available. USM Corp., FAX: (508) 988-8820.

Plugs repel electrostatic discharge

Injection-molded caps and plugs protect connectors, pins, and leads against dust and electrostatic discharge. Available in black conductive and pink static-dissipative materials, the devices are suited for use with D-subminiature, modem jack, SCSI, champ-type, threaded and non-threaded bayonet-type, and rack and panel connectors. Conductive polyethylene Caplugs offer surface resistivity of 105 ohms/square or less. Static dissipative polyethylene Caplugs are suited for clean room applications and have a surface resistivity ranging from 109 to 1014 ohms/square inch. Both Caplug types meet the MIL-B-81705C, Type II static-decay requirement. Caplugs Div., Protective Closures Co., FAX: (716) 874-1680.

Avionics make the skies safer

Avionics make the skies safer

Would you feel comfortable boarding a plane knowing a crash will occur once every week to ten days? According to NASA Administrator Dan Goldin, that's the prospect travelers will face if air-travel safety is not improved. Goldin cites studies that project traffic tripling in 20 years. But while the worldwide accident rate of about 1.5 accidents per million departures is minuscule, "If the rate of air traffic triples and we don't dramatically improve the safety rate, we're headed for major problems," since the rate has been flat for 20 years.

In February, President Clinton and Vice President Al Gore's White House Commission on Aviation Safety challenged NASA, the Federal Aviation Administration (FAA), and the Department of Defense (DOD) to reduce the accident rate by a factor of five in 10 years, and by 10 in 20 years. But where to begin?

Stuart Matthews, president of the Flight Safety Foundation, notes data show "as many as 80% of all accidents have a human-error component. About 40% of all accidents are controlled flight into terrain (CFIT), and they cause well over half of all aviation fatalities. About 50% of all accidents happen during approach and landing," he adds. Finally in the past five years, accidents caused by loss of control have challenged CFIT as the leading cause of fatalities.

In CFIT, a crew flies under control, and unaware, to an impact--often on approach and landing. Of 156 CFIT accidents between 1988 through 1994, for 108 aircraft where data were available, 81 were not equipped with a radar-based ground proximity warning system (GPWS). Loss-of-control accidents are often weather related: Disorientation induced by lack of visibility, for instance, can result in an unusual attitude--one that the crew may have little experience in handling.

In the works. Here is a sampling of technology designed to make air travel safer. Simulator-training programs will give pilots practice in avoiding loss of control. Weather-induced accidents should be curtailed with wider use of turbulence-radar and head-up displays (HUDs) giving eyes-out-of-the-cockpit data presentations. HUDs are being coupled with infrared-sensors to penetrate darkness and millimeter-wave radar to pierce rain and fog.

Other enhancements to flight safety can be realized by outfitting aircraft worldwide with collision avoidance systems currently required in the US. These devices automatically exchange position and direction information between nearby aircraft and provide avoidance maneuver instructions. Such a system on a Kazhak cargo plane could have prevented it from colliding with a Saudi 747 over India last year.

New large, multifunction liquid-crystal displays will filter information presented to pilots to only that needed for the current flight phase or requested by the crew. And the National Transportation Safety Board has asked the FAA to require that airliners have a visual indication of lift governing wing angle of attack. Such basic instrumentation is not required on commercial transports--akin to driving a car by odometer and clock to determine your speed.

Going global. Widespread satellite communications and Global Positioning System (GPS) navigation will allow "free flight" operations: Pilots will fly the best routes for weather avoidance and fuel efficiency, and not overload airway routes. Local airport GPS receivers will provide precision approach guidance for airliners.

Probably the greatest gain in crew situational awareness designed to curtail CFIT will come from enhanced GPWS. Current GPWS use radar altimeter data to determine when straight-ahead sink rate is excessive. But only sensing straight down, these systems cannot provide adequate warning of a steep rise, such as a cliff, or accommodate turning paths. And they are "desensitized" when flaps and landing gear are extended close to the ground to eliminate false alerts.

EGPWS designed by AlliedSignal Aerospace (Redmond, WA), incorporates not only altitude information but a worldwide terrain height data base that features runway locations. Aircraft altitude, position, and direction are combined by system algorithms to project a three-dimensional path--including curved paths needed to land on runways in mountainous areas. Aural warnings are typically available a minute or more from impact, as opposed to, at most, 30 sec with traditional GPWS.

A map display shows significantly higher areas in red, other higher terrain in yellow, and ground to 2,000 ft below the airplane in green. The more "solid" each color, the greater the potential threat. The EGPWS can also provide alarms for wind shear, when ground speed drops abruptly, and approaches short of a runway or to a "non-existent" runway, the most common CFIT accidents.

In the wake of one of its 757s having a CFIT crash into a mountain near Cali, Columbia, in 1995, American Airlines has ordered the AlliedSignal system for its fleet, as has United Airlines. Alaska Airlines, flying into rugged terrain with much precipitation, is installing EGPWS on its 25 737-400s. Captain Jim Applegate notes, "It's working out beautifully. It is a great enhancement to aviation safety, simple to operate, and very intuitive . Before, you had to use a paper map and try to figure out where you were." With noticeable relief, he adds, "Now the system orients you as to where the aircraft is in relation to terrain."


GPS: Where in the world are we?

The Global Positioning System (GPS) was originally developed by the Department of Defense (DOD) to provide U.S. and allied forces with precise position information anywhere on Earth. Not only can GPS determine locations of troops, ships, and aircraft but it can guide weapons such as cruise missiles. Now available for civilian use, GPS provides 156m vertical and 100m horizontal accuracy in the presence of the DOD Selective Availability (SA) induced error signal. This thwarts potential adversaries use of the system. With SA turned off, these numbers become 32m vertical and 20m horizontal.

A GPS receiver works by taking ranging codes from the satellites visible to its antenna from the 24 satellite constellation orbiting the Earth. Satellite distances are determined by measuring the signal transit time from each, and by knowing their broadcast locations, determining the antenna location. The more satellites in view, the more accurate the position.

To aid aircraft landing, differential GPS (DGPS) has been developed by several manufacturers. They place one or more GPS receivers at known surveyed locations with respect to a runway or runways. The receivers compare location information derived from GPS signals to their true location, allowing determination of the accuracy, availability, and integrity of the GPS signals. Any difference includes errors due to atmospheric delay effects as well as SA. The system broadcasts the measured errors to an approaching aircraft's GPS receiver, which receives signals from the same group of GPS satellites. On board the aircraft, the system corrects for the common error effects for an accurate navigation solution (within 2m vertically and 1.5m horizontally) to touchdown at the numbers painted on the runway end.

A single DGPS system, such as the SLS-2000 from Honeywell (Phoenix, AZ) and Pelorus (Calgary, Alberta, Canada) can serve runways at airports within a radius of 22 to 33 miles. Thus, precision approaches, including curved paths and those to parallel runways, can be used at facilities without conventional instrument landing systems.

Road to an open fieldbus standard

Road to an open fieldbus standard

A worldwide fieldbus standard will combine the best parts of a number of today's systems, says Lane--and it may not be that far off.

Design News: What advantages do industrial PCs offer compared with proprietary control systems?

Lane: Until now control systems have been pretty much run by PLCs, which are developed by one manufacturer who then usually supplies all the associated input/output devices and software. When you get on the factory floor level and start using a certain manufacturer's PLC, that tends to become the standard throughout the factory because you've got training programs to teach operators and technicians that particular language. With industrial PCs, training the workforce is easier, you get flexibility for reprogramming the system to do different things, and you're not tied to one supplier. Also, it's much easier for the factory floor to communicate with the entire enterprise computer system. It's very difficult to tie a PLC system into a total company computer system.

Q: Why would a company want to change from a PLC to an industrial PC?

A: Because industrial PCs have come down so much in cost and they're much more flexible than a PLC. They also have open operating systems like Windows, which everybody understands, and open software programs that can be bought from many different suppliers.

Q: Do you think there will eventually be a worldwide fieldbus standard?

A: That's a real difficult question. ISA has Committee SP50 investigating what will be called the Foundation Fieldbus. That's supposed to be-come a worldwide standard. The specification has been completed for more than two years now but it's not being adopted in a very rapid fashion. Some of the other systems--such as Siemens' Profibus and Phoenix Contact's Interbus S--have established themselves in the meantime while we've been waiting for this world standard to be written. Whether the Foundation Fieldbus will eventually succeed or whether a different fieldbus system will become the champion in the long term is difficult to say at the moment. I think that other systems will evolve from the ones that exist today and then gain worldwide acceptance and that by the end of this year one major new standard will be established.

Q: What is "block I/O"?

A: The problem is that some of the I/O for fieldbuses isn't open--you can only get it from the manufacturer who effectively invented that particular fieldbus system. And then, traditionally, that I/O comes in blocks of usually 16 channels, with all 16 being the same--all analog or all digital and all input or all output. Which means you're paying for multiples of 16 whether you need them or not. What you also need is a higher granularity--that is, a lower channel count per module. The WAGO I/O System offers modules with as few as two channels, so you only buy what you need.

Q: What are some other drawbacks of block I/O?

A: Block I/O isn't open, in that when you buy the block I/O you buy it for the particular fieldbus you have chosen. WAGO's I/O is not only flexible in terms of number of channels, but it's also flexible in terms of which fieldbus it can be used with. Once the I/O is wired, you haven't yet decided which fieldbus system it's going to work with. The last part of the assembly is the bus coupler, which makes that set of I/O unique to a particular fieldbus.

Q: Which fieldbus standards does WAGO's I/O System work with?

A: We support all of the common fieldbuses, including Profibus, Interbus S, ModBus, LonWorks, and the CAN fieldbuses. We're discussing whether to support the Fieldbus Foundation standard. It's going to be very expensive to support, and until there's a demonstrated use of the system we won't do that development work.

Q: What should a design engineer consider when choosing a fieldbus?

A: He or she needs to ask, What is the operation and how critical is a failure? For instance if you're running a nuclear power plant or a petrochemical facility, and the control system goes down, that's pretty critical. If you're running an assembly operation, a failure is less critical. Some fieldbus systems retain more information when the system goes down, and can remember where the process is when the system comes back up. You pay for what you get--the systems that retain the most data are also the most expensive.

Engineering News

Engineering News

Run silent, run cheap

Groton, CT--The primary purpose of a nuclear attack submarine (SSN) is to attack enemy submarines. However, politics have left the bulk of the Soviet-cum-Russian submarine force rusting at its moorings, and American submarine makers rather high and dry.

Like a dive alarm, the advent of real peace has awakened officials at Electric Boat to the necessity of redefining the business of designing and building their principle--and, in reality, only--product. The defense contractor has followed the examples of Boeing and Chrysler in adopting the CATIA CAD/CAM package from Dassault Systemes, Paris, France, for nearly all aspects of the product development cycle.

The latest program to get the green light at Groton is the so-called New Attack Submarine (NSSN), which the Navy wants to replace its maturing fleet of Los Angeles-class SSNs starting around 2004. Design of the new boats is well advanced, and engineers say CATIA has been instrumental every step of the way. In fact, NSSN is the largest, most complicated CATIA project anywhere in the world. This represents a sea change at Electric Boat. All other submarines were designed on paper, from the Holland built in 1900 up to and including, astonishingly, the Seawolf-class.

One of our submarines is missing. Conceived in the Red October era, the Seawolf is the most capable attack sub ever built. It is also the most expensive. Each boat costs between $2.5 and $3 billion.

The Seawolf displaces 9,150 tons submerged compared to the Los Angeles's 6,900, enabling greater weapons load and patrol endurance. The former is supposed to be quieter at high speed than the latter is sitting at the pier. In the sub-hunt game, quietness equals victory.

The first unit, USS Seawolf, is undergoing sea trials. The second, USS Connecticut, should be completed in 1998. Funding for a third unit has been approved for delivery in 2001. And that's all she wrote.

"We're on life-support," admits Craig Haines, Electric Boat's vice president of quality and information technology. "The Seawolf will just keep us in business until the NSSN goes into production."

"The Navy can't afford to buy 20 Seawolves," explains William Lennon, deputy program manager for the New Attack Submarine. "So our goal is to provide certain Seawolf-type capabilities but cheaper."

Cheaper means each NSSN will cost about half as much as a Seawolf. The new class is significantly smaller, displacing 7,700 tons, and will not be quite as fast, nor as deep diving, nor as quiet as its better-appointed predecessor. However, the NSSN will offer a number of advantages in performance and firepower over the Los Angeles boats, such as a vertical launch system for tactical missiles similar to those found on Arleigh Burke-class destroyers and later Ticonderoga-class cruisers.

Electric Boat is also designing NSSN with post-Cold War combat in mind. The Navy has specified requirements for the new sub to carry and deploy troops, unmanned submersibles, and advanced mines.

Perhaps the most innovative design feature of NSSN is its modular construction arrangement. A series of bays, each supporting related equipment and functions, slide into sections of the sub's pressure hull like boards in a PC. The NSSN is designed to be disassembled, so particular modules can be removed for ease of maintenance or even replacement by more advanced modules. This way, the Navy hopes to keep the NSSN up to date and effective for decades.

Diving deep. In order to survive in the submarine business, Electric Boat found it necessary to embrace those design and manufacturing technologies that have helped revitalize other troubled industries in the not-too-distant past. The transition has not been tentative: Over 950 seats of CATIA Version 4 have been installed on a mainframe and a network of 300 IBM RS/6000 workstations. What's more, every component and section of the NSSN will be designed electronically and evaluated in digital or physical mock-up before steel is ordered.

"The most important ability we have obtained from migrating to CAD is flexibility," Lennon says. As an example, he cites an early design specification for NSSN that dispensed with dihedrals, which are small fin-like planes attached near the rudders. Eliminating them would reduce drag. However, subsequent analysis showed the boat's stability would suffer in their absence, and the dihedrals were put back in the design. "Similar revisions to the design at such a late date under a paper-based system would have caused several months' delay," Lennon says. "With CAD, the design team handled the changes in less than a month."

According to Haines, a major time- and cost-saving device of the NSSN program has been to link the design and manufacturing processes. "Historically, design was a single activity by contract," Haines says. "Now, the Navy has awarded a joint design and build contract for the NSSN. For the first time, this allows us to approach a project in a totally integrated way."

Linkage has been achieved through a common database of CATIA geometry accessible by both design and manufacturing engineers. Product data management (PDM) is regarded as key to this achievement, and the CATIA Data Management system was cited as one of the chief reasons Electric Boat went with Dassault/IBM. PDM works in concert with the Artemis product definition system from Computer Sciences Corp. (CSC) for document control and product scheduling. In addition, Electric Boat has outsourced all "non-strategic" application development, processing, and MIS functions to CSC.

Haines insists PDM and software-based program definition have drastically improved the efficiency of the NSSN program compared with previous efforts. "In one instance, on the Seawolf we found the same part had 16 different numbers," he says. "People on different teams just couldn't find an existing number for the part, so they gave it a new one. Now that all the engineering teams are linked together, this doesn't happen."

Many of the parts going into NSSN never would have made the cut on earlier submarines. This is not through lack of quality, Lennon is quick to point out, but because they were not to military specifications. "We have found that 90% of the fasteners on a submarine can be commercial grade," Lennon says. "That's resulting in a savings on NSSN of $500,000 per unit. We are finding similar savings with off-the-shelf enclosures and other systems as well."

Electric Boat's engineers provide potential vendors with a component's performance requirements, volume, and touch-points. The component designers return drawings or CAD geometry--preferably the latter--which are fitted into the CATIA assembly. "It's an iterative process," Lennon explains. "CAD allows it to happen much more smoothly."

One of the most important design tools enabled by CATIA is Electric Boat's home-grown electronic visualization system, which can display life-size assemblies on a large screen. Designers, manufacturers, and representatives of the Navy can navigate through virtual mock-ups of NSSN compartments.

"We used to have to build physical mock-ups three to five times before the customer was happy," Lennon relates, indicating each iteration might cost $1 million. "Then we would generate 2-D drawings from the approved version and deliver them to the shipyard, who had concerns too."

Changes can readily be made to the CATIA geometry that support the electronic visualizations. Furthermore, when an arrangement has been agreed upon by all parties, including the shipyard, the 3-D CAD models are ready to drive the manufacturing process.

The only section of the NSSN being modeled in wood and plastic is the propulsion module, which supports the S9G pressurized water nuclear reactor. Notes Haines, with the barest hint of impatience: "The nuclear navy customer is not persuaded the aft section of a submarine can be built without a full-scale mock-up."


Laser sensor controls agricultural spraying

Orlando, FL--Schwartz Electro-Optics has adapted its laser range-finder and imaging technology to control agricultural spraying. The precision possible with the Treesense system cuts overspraying. Result: minimal environmental impact and cost savings on sprayants.

Treesense is based on Schwartz's Autosense II vehicle detection and classification system that scans an eye-safe infrared indium gallium arsenide pulsed diode laser beam. A silicon avalanche photodiode detector senses the reflected beam.

In agricultural applications, the sensor detects the presence and extent of foliage on each side of the sprayer. Spraying is limited to those volumes containing foliage--the sensor lets the sprayer accommodate both small and large adjacent trees as well as differing patterns and extent of growth.

BEI, South Haven, MI, was the first to outfit a sprayer, its Curtec-2000, with Treesense. Luis Martinez, a grower representative and vice president of Curtec of Florida, a BEI sprayer distributor, says the ability to accurately gauge a small tree means "you don't drown the tree. Material-wise we can save 15 to 60%, depending on how many resets are in the grove." Resets are new trees planted to replace dead ones, which in the average grove is 5% per year. He adds, "That's a significant amount with a tank containing $1,000 worth of material."

Previous sensing systems based on ultrasonics require more detectors and components, according to Martinez, and can pick up false readings due to birds, for example. Detection with the laser-based method can be thresholded to avoid such spurious positives. While orchard applications require a range of about 30 feet, which both sensor types can handle, Martinez says the laser system can be adapted to row-crop spraying using boom sprayers up to 50 feet long.

Treesense-equipped sprayers can speed along at 3 to 5 mph and still get a precise growth profile. The system microprocessor allows for custom software development for individual growers. This can include census information such as the number of resets in a grove block, the extent of vegetation, or the time to accomplish spraying of various chemicals. Growers could also program the system to estimate yield of fruit by reading orchard color.


Thermal-spray technology tops U.S. Plunkett Awards

Turnberry Isle, FL--The company that developed a one-step method for the thermal spraying of fluoropolymer ceramic and metal composite coatings walked off with the first-place prize for U.S. entries in the 1997 DuPont Plunkett Awards for Innovation with Teflon(R) at an industry award ceremony. Similar awards were presented to European and Asia Pacific winners.

Spray-Tech Inc., Newton, CT, in conjunction with Frank N. Logo Associates, East Northport, NY, perfected the ceramic and metal composite coating technology. It provides low friction, low wear, corrosion protection, and other benefits of Teflon fluoropolymer resin for machine parts and tooling. Key to the patented system is a thermal barrier that protects particles of Teflon PTFE resin against destruction by the extreme heat of thermal spraying.

Compared with a conventional two-step process, the technology saves energy, eliminates added quality-assurance steps, and improves performance reliability. The process also emits no VOCs and eliminates waste. The resulting composite coatings with the embedded particles of Teflon have demonstrated 50% less friction and 20% longer wear life than coatings without the material.

Second prize went to MCR Oil Tools Corp., Burleson,TX, for a radial cutting torch. The torch pyrotechnically cuts tubing in a fraction of a second--on site--in oil and gas wells. It uses a mixture of Teflon PTFE resin and powdered metal as a gas generator. The faster cutting technique reduces labor, rig operating time, and energy costs.

Lowered down the well, the radial cutting torch is positioned and then "fired" to produce a high-velocity jet of molten metal and gas that cuts through well pipes in a fraction of a second. The Department of Energy has calculated that, over time, the Radial Cutting Torch can save energy producers some $40 billion in costs.

White Knight Pumps & Fittings Inc., Hemlock, MI, won third prize for its Pneumatic LogicTM shifting mechanism. The device, made entirely of Teflon, is used in the company's reciprocating pumps. Because they are 100% fluoropolymer resins, the pumps constitute a major advance in maintaining the high purity of fluids in semiconductor and chemical processing operations.

The pump has two pistons in opposing chambers. The pistons are connected so that while one expels fluid from its chamber, the other draws on fluid. Driving each piston is a bellows that expands under air pressure and contracts when pressure is released. Air flow to the bellows is controlled by the shifting mechanism, which incorporates a shuttle valve.

International winners. Award winners also were recognized in the European and Asia Pacific regions. On the European scene, first prize went to Trifluor GmbH, Ochtrup, Germany--shared with 2H Kunststoff Gmbh, Wettingen, Germany, and Metallform Gmbh, Imst, Austria--for the Plexoform(R) wet, flexible flue liner system for low-temperature or calorific-value heating boiler systems. Lenzing AG, Lenzing, Austria, received the second prize for its PROFILEN(R) staple fiber for needle felts used as scrims and sewing thread in high-temperature filtration; Kureha Chemical Gmbh, Dusseldorf, Germany, took the third prize for its PTFE fluoropolymer reinforced with Kreca(R) carbon fibers to produce gaskets, seals, and wear rings with improved properties.

Award winners for the Asia Pacific region included: first prize, Nippon Valqua Industries Ltd., Tokyo, Japan, for a method to line large tanks with fluoropolymer sheets at the customer's site; second prize, Heliro Pty Ltd., South Wales, Australia, for a process to injection mold small, complex insulators for coaxial cable connectors; and third prize, Chukoh Chemical Industries LTD., Tokyo, for its heat-resistant laminating belt used in corrugated board manufacturing.

The awards are named after Dr. Roy J. Plunkett, the DuPont scientist who discovered the original PTFE fluoropolymer that DuPont markets under the Teflon trademark. First-place winners received $5,000, second-place winners $3,000, and third-place winners $1,500. Judges included: Drew Azzara, vice president, American Society of Testing and Materials; Yasuhiro Koike, associate professor, Department of Science and Technology, Keio University, Yokohama, Japan; Piet J. Lemstra, professor, Laboratory of Polymer Technology, Eindhoven University of Technology, Eindhoven, The Netherlands; Ann Van Orden, assistant professor, Department of Mechanical Engineering, Old Dominion University, Norfolk, VA; Alvin Scolnick, vice president, National Electrical Manufacturers Association, Rosslyn, Virginia; and Gary Chamberlain, senior editor, Design News.


Engineering take-out hits the spot

Chelmsford, MA--APC, a Billerica, MA-based manufacturer of uninterruptable power supplies (UPSs), possesses an extensive staff of mechanical and electrical engineers. Nevertheless, it sought specialized engineering support elsewhere for a ground-breaking new product--code named "Dark Star"--that required a radical enclosure design. The company brought in two ID firms for initial consultations on the pitfalls and the potentials of the design concept, and selected the Bleck Design Group to see Dark Star realized.

According to Tom Eagan, director of engineering at Bleck, his company's role was to supplement APC's internal resources by tackling particularly challenging aspects of the project--in particular those that called for the engineering of structural and functional plastic components.

The goal of Dark Star was to develop an easy-to-manufacture UPS system with minimized component inventory and maximized configuration possibilities.

Bleck's solution was to develop a building-block approach, with an elaborate main enclosure--termed, the garage--as the cornerstone. This 20-lb gas-counter-pressure-formed unpainted structural foam part would accept multiple variations of transformer, battery, converter, and electronics configurations. Such an arrangement would permit APC to package configurations and upgrades such as field kits that the customer would unwrap and slip into place in the garage. What's more, the components were to be blind-mated and hot-swapable.

"While aesthetic quality, structural integrity, and blind-mate design were challenging, the biggest challenge mechanically was balancing the constraints for the various mounting and design features," Eagan says. He indicates designing such a robust enclosure would not have been possible without the use of high-end CAD systems. Bleck engineers did much of the design work for Dark Star using the surface-modeling tools of Euclid 3 from Matra Datavision, Andover, MA.

APC has just started selling the finished UPS product, now dubbed Symmetria. The entire product-development cycle was just over two years. "Symmetria was made possible by a coordinated effort," Eagan says. "No one organization could have achieved it on its own."


Enclosure weathers plant-floor conditions

Foxboro, MA--When The Foxboro Co. set out to design its newest process control system, the company knew it needed a tough enclosure. Destined for plant-floor applications in the food and pharmaceutical industries, the system had to withstand daily hose downs and exposure to harsh chemicals. The company's choice: the PC industrial enclosure from Rittal Corp., Springfield, OH.

Measuring 6x3x3 ft, the sealed NEMA 4X enclosure houses a process control computer with intelligent automation software. The system features a CRT that provides a status update, as well as both keyboard and mouse that are watertight.

The enclosure itself is stainless steel to resist corrosion. It's available with a choice of three cooling options: an industrial air conditioner, a water-cooled unit, or an air-cooling system; and is delivered with the cooling method of choice built in. The enclosure's upper door is available in glass for maximum visibility, or in shatterproof fiberglass to prevent breakage in the event of an accident.

In addition to the variety of design options, Foxboro chose Rittal's PC enclosure because of its reasonable cost. Add to that past dealings with Rittal that were successful. "We also liked the fact that Rittal does all its own design and development," says Chris Dhupar, hardware development manager at Foxboro. "And, because it's a multinational company, we don't have to ship products from the U.S. to Europe. Rittal produces the same enclosures in Europe as it does here, so we can have products shipped directly to our European customers."


3-D visualization clears up molecular confusion

Morris Plains, NJ--Re-searchers at Parke-Davis use molecular modeling to create, modify, study, and test interactions between molecules in their efforts to design new drugs. In the past, they relied on tinker-toy models and crude wireframe computer drawings to visualize the complex interaction of drug and biological molecules. However, these tools did not adequately display the nooks, crannies, bumps, canyons, and holes of the molecules' topography.

Now, Parke-Davis uses high-speed workstations, advanced modeling software, and the 3-D visualization capabilities of CrystalEyes eyewear from Stereographics, San Mateo, CA, to create near-exact visual replicas of complex molecules.

"With CrystalEyes we've gained an understanding of the forces and factors involved in making a compound a potent drug. Before using this equipment, we didn't fully appreciate the role that those properties played," says Parke-Davis Research Associate Dan Ortwine.

CrystalEyes works with the user's computer display and software to transmit separate left-eye/right-eye images, creating the illusion that on-screen objects have depth and presence. The result: Crisp stereo 3-D images delivered without ghosting or double-image artifacts.

Alternately displaying left- and right-eye perspectives on a monitor using a standard bandwidth solves a major problem of the past--true control of the z axis. For remote manipulation and viewing of objects, stereo 3-D gives the user control of changes made to a structure on the screen along all axes, including the z axis. This control is essential for exacting real-time processes such as the docking procedure critical to modeling molecular interactions.

Today, instead of making 200 molecules using the old methods, researchers need create only 50 because they can reject the remainder with greater speed and certainty. "We know in advance that a situation won't work because a drug molecule doesn't fit into a cavity," says Ortwine.


Phenolic compound reduces brake-cylinder piston weight

Winona, MN--Performance advantages such as heat resistance and dimensional stability make thermosets ideal for replacing metals in many automotive applications. The latest: brake-cylinder pistons for articulated dump trucks, front-end loaders, container handlers, and lift trucks.

Component engineers at Rockwell Automotive replaced the previous piston's steel core with Fiberite's FM 4029F-1 glass- and mineral-reinforced phenolic molding compound. The material's heat resistance helps protect the piston's rubber seals from heat conducted through the brake-lining backing plate. This minimizes seal hardening and extends the seals' life, according to Pat Cadaret, Rockwell's senior project engineer for off-highway axles and brakes.

Another advantage: The piston weighs 66% less than its all-steel counterpart. "This means less drag after braking and longer lining life. Our O-ring retraction system requires less force and quickly backs off the pad after braking," says Rockwell Brake Engineering Manager Bill Hayes.

Thermal specifications include a glass transition temperature above 572F and a coefficient of thermal expansion of 13 ppm/C. Hayes reports that test comparisons of two other molding compounds indicate FM 4029F-1 material is most easily processed using Rockwell's compression-molding technology.

The number of new thermoset applications nearing production or in development at OEMs or tier one suppliers in both the U.S. and Europe is at an all time high. As thermosets find their way into more under-the-hood applications such as valve covers, engineers are investigating other applications such as fuel rails, intake manifolds, throttle bodies, and water and oil pumps.


Milstar payload delivered

Sunnyvale, CA--Milstar prime contractor Lockheed-Martin recently received the first medium-data-rate (MDR) payload for the next block of upgraded Milstar communications satellites. The military will begin launching the new satellites aboard Titan IV-Centaur vehicles in 1999.

Milstar satellites currently in orbit are Block I. They feature a low-data-rate (LDR) payload supplied by TRW Space and Electronics that transmits information at 75 to 2,400 bps. The new Block II spacecraft will carry both an LDR payload from TRW and an MDR payload to extend the satellite's data-rate transmit/receive capability to 1.544 Mbps. Delivery of the MDR payload, built by Hughes Space and Communications Company, represents a transition to the Block II configuration.

The new payload carries two specially designed nulling antennae that can pinpoint a jammer's direction and temporarily block, or null, signals from that direction. Jam-free operations can be continued in other directions without losing communications.

Milstar's "Switchboard-in-the-Sky" approach uses five technologies not found in previous military satellite communications systems. These are:

  • On-board signal processing

  • On-board signal routing

  • On-board resource control

  • Crossbanding

  • Satellite crosslinks

The satellite's ability to frequency-hop across its full 2-GHz bandwidth--a first for communications satellites--also enhances security.


Tensioned spokes redefine the wheel

Wilton, CT--Bicycle enthusiasts and racers have something new to spend their money on: compression-molded carbon-composite wheels with spokes that suspend the wheel hub in tension. The design results in enhanced lateral rigidity and the ability of the wheel to protect the rider from shock, says Spinergy Inc.

Making the family of rev-X(R) wheels involves a three-step procedure, says Raphael Schlanger, engineering manager at Spinergy. First, the rim, all eight spokes, and a hub-flange area are molded as one integral unit. (The multi-layer layup uses both woven and unidirectional carbon fiber.) Next, a rim of 6061 T6 aluminum extrusion, rolled and joined at the ends, is bonded to the composite rim.

Last in the sequence comes hub bonding. "After the rim is bonded up, you have four spokes coming down on each side," Schlanger explains. Each set of spokes comes together at a hub flange. "We pull on those two hub-flange areas, spacing them apart from each other along the axis of the axle. Then you put your hub in there, and lock the wheel in the stretched position." This procedure puts the spokes under a tensile load.

The tensioned spoke system results in a number of benefits, according to Schlanger. Most carbon-fiber wheel designs now in use employ compression-spoke wheels. A compression spoke functions like a column under a compression load. Shock caused by a bump or other obstacle travels through that spoke, through the axle and bicycle frame, to the rider.

With a tensioned spoke wheel, shock may reduce tension in the spoke, but the spoke does not go into compression. Instead, all of the other spokes take up tension to compensate. This design "distributes shock throughout the whole wheel," Schlanger explains, "which means you don't have to make any one part of the wheel exceptionally strong because the impact affects the whole wheel and the design distributes the load throughout the wheel. So you can make a lighter wheel."

In addition, because the carbon fibers are in tension, the design makes the structure stiffer and enhances the wheel's lateral rigidity. A compression spoke wheel requires "a whole lot of material and a lot of section, particularly at the base of the spoke near the hub, to achieve any kind of respectable lateral rigidity," asserts Schlanger. Compression also forces the composite's resin to carry load. But tension loads use the fiber in an optimum way.

Given that pairs of rev-X wheels cost from $750 to more than $1,000, what do they offer a rider, aside from clever engineering? "There's a definite aerodynamic benefit," says Schlanger "The rim cross section is teardrop shaped; it's much deeper than your standard rim. There's much less flow separation as the rim moves through the air." He says that the wheel develops less than half the drag produced by a conventional wire-spoke wheel. "Bike racers might ride several hundred miles a week. And when they ride these wheels they notice the difference."


Flat panel directly replaces CRT

Los Gatos, CA--Measuring five inches deep, this 12.1-inch plug-and-play graphics monitor, called the VueStationTM, supports 256K colors with 800x600-pixel resolution (SVGA).

Made by National Display Systems (NDS), the panels use the firm's proprietary SmartSync technology to translate analog VGA and SVGA signals to a digital format. SmartSync employs an interface board with features that make the flat panel behave like a conventional CRT monitor, according to NDS's Hai Nguyen. In this design, a microcontroller based on an Intel 8088 microprocessor manages the signal going in to drive the flat panel. According to NDS, SmartSync makes the flat panel as easy to use as a standard multi-sync monitor.

In addition to saving space, VueStation consumes less power than a CRT. "A CRT consumes about 35 to 40W, this guy's only going to consume 10 to 15W at the most," explains Nguyen. Unit price for the 12.1-inch SVGA model is $2,300.


Plain plastic bearings weather bumps, sand, and sea water

Costa Mesa, CA--Imagine completing a 2,000-mile bicycle tour without ever hearing that annoying gnash emanating from the front hub. Plain plastic bearings employed in the front wheel hub, headset, and bottom bracket of RBH Machine's commuter-style bicycle reduced the number of parts, cut costs, improved reliability, and simplified maintenance, say company engineers.

Failed bearings on long bike treks mean scored rolling elements, galled races, or maladjusted cones. And if you're a tool-packing biker carrying spare parts, it means roadside greasing and adjustment that often results in sifting sand for balls dropped during reassembly.

Front wheel hubs, steering mechanisms, and pedal-crank mechanisms traditionally employ ball bearings. Engineers generally consider plain bearings, especially plastic plain bearings, unsuitable for these applications because of load limitations, high clearances, and increased friction. Iglide oil-free bearings from Igus Inc., East Providence, RI, have changed the way bicycle designers think.

The Iglide L1 plain bearing design consists of glide pads connected by thin film hinges. L1s contract and expand, maintaining close tolerances under wide temperature and humidity ranges. "Friction has simply not been a problem in this application," says RBH Machine's Richard Harvey. "There is no noticeable difference between Iglide L1s and ball bearings."

Igus supplied off-the-shelf L1s to RBH Machine, and Harvey simply cut them to length. The design, tested on a 30-bicycle fleet, has patent applications filed for the front hub and bottom bracket designs. "We purposely drove the bikes into curbs, on the beach, through salt water, and on dirt trails," says Harvey. "Several bicycles have over 2,000 miles on them without any sign of bearing wear."

Harvey estimates that using L1s saved $20 per headset and is so satisfied with the bearings' performance that he gives a lifetime warranty on Iglide-equipped bikes.


Plastic layer fights graffiti

Baltimore, MD--By placing a layer of DuPont's Tedlar(R) PVF film over maps and other signage, Globe Transportation Graphics protects the signs from graffiti. Mass transit systems in Maryland and Virginia use Globe Transportation's TransGrafix(R) signage and markings, which combine high-contrast colors, low-glare finish, raised letters, Grade 2 Braille, and other tactile features.

TransGrafix products employ a top layer of Tedlar TUT10BG3 fused to a subsurface printed polycarbonate substrate. Globe Transportation Graphics then embosses the structure with tactile features and coats its back surface with a high-performance foamed pressure-sensitive adhesive.

Globe Transportation allowed ballpoint pen ink to dry on Tedlar for 24 hours. All-purpose cleaner removed the ink. Samples of Tedlar exposed to a 10% solution of room-temperature hydrochloric acid for one year remained undamaged, according to Duke Zimmerman, Globe Transportation's president.

Technology bulletin

Technology bulletin

Web-thin 'miracle' fiber offers impenetrable protection

A spacecraft traverses the galaxy powered by solar sails thinner than a spider's web. Waterproof bandages inhibit bacteria and stop bleeding on contact, while allowing air through so wounds heal quickly. A soldier walks through an enemy's biological or chemical spray without a care because the clothing he wears automatically decontaminates itself. That's what scientists at the Natick (MA) Research, Development and Engineering Center hope to achieve with a technique called electrospinning. The lab's Heidi Schreuder-Gibson reports that the process involves charging to high voltage a suspended droplet of polymer solution. At a certain voltage, a fine jet of the solution shoots out toward a grounded target, forming a continuous multifilament fiber of polymer. The fiber splays as it reaches the target, dries, and is collected as an interconnected web of small fibers. The technique gives scientists the capacity to lace together a variety of polymers and fibers to produce ultra-thin layers of protection. FAX (508) 233-5390.


Fuel cell runs 9,500 hours nonstop

International Fuel Cells reports that a commercial fuel cell built by its subsidiary, ONSI Corp., has set a world record for continuous use. The fuel cell, an ONSI PC25TM Power Plant installed in a Japanese office building, operated for 9,500 hours before being shut down for scheduled inspections. The previous record, 9,477 hours, also was set by an ONSI fuel cell purchased by Tokyo Gas. The cell uses an electrochemical process to directly convert chemical energy into electricity and hot water. The chemical energy normally comes from hydrogen contained in natural gas, and, for automotive applications, could come from regular gasoline. However, the cells do not burn the gas, so they operate virtually pollution-free. The units owned by Tokyo Gas are part of an ONSI fleet of more than 100 fuel cells in operation around the world. FAX (860) 727-2216.


Hydrogen-fueled bus joins public transit fleet

Trials are under way in Georgia of a hydrogen-fueled bus that emits practically no emissions. The bus is one of the first vehicles to store hydrogen fuel in metal hydrides rather than hydrogen fuel cells. When the hydrides are heated using energy from the bus's generator, they slowly release hydrogen gas. The gas fuels a standard internal combustion engine, which drives an electrical generator that keeps the bus's batteries charged. Burning hydrogen fuel produces water vapor that contains no carbon dioxide and little or no nitrogen oxide. The H2Fuel bus was developed by a coalition that includes the Department of Energy, Augusta-Richmond County Public Transport, the Westinghouse Savannah River Co., and the Georgia Institute of Technology. E-mail charles.stancil@gtri.gatech.edu.


Single crystals move more with high voltage

High voltage causes a family of crystals known as relaxor ferroelectrics to deform 10 times more than any other material currently known, according to a Pennsylvania State University scientist. "No one has seen this large a movement before," says Thomas R. Shrout, a professor of materials at the University's Materials Research Laboratory. Ultrasound equipment, acoustic transducers, devices to position specimens under electron microscopes, and switches commonly employ such piezoelectric materials. Most common are polycrystalline like PZT--lead zirconate titanate. Relaxor ferroelectrics like PZN-PT--lead zirconate niobate lead titanate--however, can be grown as single crystals. Shrout and a post-doctoral researcher were trying to improve the piezoelectric performance of medical ultrasound devices by growing such large single crystals. They found the material deformed 1.7%. A one centimeter crystal elongates to 1.017 centimeters, 10 times more deformation than other materials. With such a material, devices can either use crystals that are 10 times smaller with the same result, or not alter the size of the piezoelectric material and achieve 10 times the effect. E-mail TShrout@alpha.mrl.psu.


Electromagnetic valves increase engine efficiency

Vehicle makers long have sought an electronic way to control engine intake and exhaust valves to meet market demands for greater engine performance and improved fuel economy. Engineers at Southwest Research Institute (SwRI) are testing a novel electromagnetic valve actuator (EVA) system that provides these benefits. The EVA system is one of a series of electromagnetic valves patented by Aura Systems, El Segundo, CA. It is being tested in a two-cylinder, 18-hp Kohler Command utility engine converted by SwRI to operate on natural gas. The system places one actuator at each valve site. Two opposing spring coils are fitted at each site, providing the primary force to open and close the valves, and to reduce power consumption and increase reliability. The spring forces are supplemented by electromagnetic force from the EVA coils. Intake and exhaust valves are independently computer controlled and timed, making it possible to fine-tune the air-fuel and exhaust flows to engine needs in a way "no camshaft can," says SwRI Principal Investigator Daniel Podnar. FAX (210) 522-3547.


Lead-free alloy exhibits high degree of machinability

Reynolds Metals Co. has introduced a patented, lead-free alloy that it claims provides superior levels of machinability compared to conventional alloys. The EZCUT AAX6030 alloy can be machined wet or dry at high rates to produce an excellent surface finish and good welding, brazing, and anodizing characteristics, according to Rodney E. Hanneman, Reynolds' VP of quality assurance and technology. The alloy also provides the corrosion resistance of AA6061 and equal or higher strengths than existing alloys in the same extruded condition without cold finish. "EZCUT AAX6030 can increase machining productivity up to 150% because it forms smaller, finer chips than other 6000-series alloys, and it is equivalent to 2011, the industry standard," Hanneman adds. E-mail rtolbrys@lanmail.rmc.com.


Material replaces multi-layer steel with 'soft' gaskets

DuPont and Frenzelit have unveiled a new material that "will revolutionize automotive gaskets." The material, Frenzelit's Novatec Engineered Graphite combined with DuPont's Kevlar(R) fiber, offers significant cost and ratio performance benefits over conventional multi-layer steel gaskets, according to Hans van den Hurk, DuPont Europe short fibers sector marketing manager. Multi-layer steel gaskets have been recognized for having good basic features, but require complex, high-cost production processes. Graphite, which offers the strength and ability to remain stable at up to 450C (842F), is an effective alternative that also promises an improved price/performance ratio. However, when used exclusively, graphite suffers from a certain brittleness that makes it delicate to handle and install. With the Frenzelit/DuPont partnership, adding Kevlar resulted in a material that significantly extends the handling and performance range of graphite gaskets, while providing a 100% secure seal, van den Hurk explains. FAX (810) 583-4556.


Metal-detecting molecules may aid water recycling

A biochemical technique being refined at Sandia National Laboratories may soon enable sensors that can, in seconds, detect the equivalent of one contaminant particle among a billion other molecules in waste streams. The technology makes use of molecular bundles called "liposomes" tailored to react with certain metal ions in solution. The Sandia team is looking at ways to entrap these spherical liposomes in porous silica materials--essentially whipped glasses--which may open doors to many practical inventions, including water-purity sensors in microchip factories or molecule-sized metal detectors for environmental cleanup operations. The technique eventually could result in a family of biosensors that would provide at-home detection of viruses. At Sandia, the team developed a way to entrap the elusive liposomes in sol-gels, a class of solid, lightweight, silica-based materials. E-Mail dysasak@sandia.gov.


Ultraviolet technology aimed at combating tuberculosis

New York City will serve as the site for the nation's first collective, multi-city pilot effort to use ultraviolet (UV) technology to help stop the spread of tuberculosis. The initial installation of the TB-bacteria-fighting lamps will take place at a drop-in center for the homeless in mid-town Manhattan. The national TB Coalition Project will conduct the five-year trial to examine the effects of UV germicidal irradiation (UVGI) and ventilation to curb TB in such homeless shelters. Co-sponsors include Saint Vincents Hospital, Con Edison, and the Electric Power Research Institute. New York has an overall TB rate five times the national average, with 75% more carriers than the average among homeless individuals. Combined with proper ventilation, current UVGI technology works by cleansing air of TB bacteria, often spread unwittingly by people with the active disease. UV room disinfection can be accomplished with specially designed, ceiling-mounted fixtures. The study will determine if these units, when placed at least seven feet above the floor surface, provide safe room disinfection via UV (254 nm) wavelengths, with no significant risk to occupants. FAX (415) 855-2731.


Geologists help verify nuclear test ban treaty

President Clinton, leaders of four other superpowers, and 140 other nations have signed the Comprehensive Test Ban Treaty (CTBT), prohibiting the testing of nuclear devices around the globe. But how do you enforce the treaty? Cornell University geologists hope to lend a hand. To assist in the effective monitoring of whether a nuclear bomb has been detonated, the geologists are compiling an interactive Geographic Information System (GIS), a database of global seismological, geologic, geophysical, remote sensing, and geographic information. "The treaty calls for on-site inspection if a country suspects that another country is cheating," says Muawia Barazangi, senior scientist at Cornell's Department of Geological sciences. "You need a database at hand swiftly; you can't wait weeks for a report. Otherwise the evidence may disappear." This digital database is easy to access via the World Wide Web (http://atlas.geo.cornell.edu). FAX (607) 257-6397.

Washington beat

Washington beat

Pentagon launches web site a
for swapping technology ideas

The Defense Department has set up an Internet forum for open discussion of current and evolving technology topics. Called the Technology Navigator (TN), the site attracted engineers' attention in demonstrations at the June TechNet '97 exhibition in Washington, DC. The Defense Technical Information Center designed TN for use by industry, academia, and government agencies. The center envisions TN as a nexus for technologists to share research data and related information on products, pilot programs, studies, and findings. Users can post events, discuss ideas, develop problem-solving applications, and showcase products and services to a worldwide government audience. TN's address is http://www.dtic.mil/technav.

Many industries reclassified as SIC system is replaced

You may soon officially be in a different industry than you were at the end of last year--even if you haven't switched jobs. In the United States, the North American Industrial Classification System (NAICS) is replacing the Standard Industrial Classification, a system that federal, state, and local governments; the business community; and the general public have used since the 1930s. NAICS reflects mammoth changes in technology and in the growth and diversification of services. The 10 broad sectors in the old system are expanded to 20. One new one is the Professional, Scientific, and Technical Services Sector. It recognizes industries that rely primarily on human capital, including engineering. Among new categories are semiconductor machinery manufacturing, fiber-optic cable manufacturing, satellite communications, and cellular and other wireless communications. For details on NAICS, go to the Census Bureau Web site at http://www.census.gov/epcd/www/naics.asp.


New head-restraint designs range from simple to complex

While auto safety regulators struggle over setting new standards for head restraints, designers have come up with a variety of possibilities. The Insurance Institute for Highway Safety in Arlington, VA, surveyed what's new and what may be required in future cars. Among the simplest ideas is the addition of locks to adjustable head restraints so they won't be pushed down in crashes. Lear Corp. is working on a more sophisticated approach. Its system automatically positions the restraint according to the passenger's height. Two sensors in the top of the restraint would determine adjustments. BMW and Mercedes offer head restraints that reposition themselves whenever an occupant adjusts the entire seat. Volvo and Autoliv in Sweden are experimenting with a seat and head-restraint arrangement that rotates slightly in rear-end collisions to distribute forces more evenly. Some 1998 Saab models will have a new head restraint that pivots up and forward according to the amount of pressure the occupant puts on the seat back.


Sharper leading edges foreseen from tests of thermal material

Ground and flight tests this year of ceramic materials that withstand ultra-high temperatures present exciting possibilities to designers of aerospace vehicles. The materials have remained stable at temperatures between 1,700 and 2,000C in the presence of high-velocity dissociated air, like that encountered during a vehicle's reentry from outer space. The tests are done in arcjet facilities of the National Aeronautics and Space Administration. More spectacular was the materials' performance as the covering for a test nose cone that plummeted into the Pacific at a blistering speed from outer space. The reentry vehicle had a nose tip with a radius of only 0.141 inch. Because these new ceramic materials do not melt during reentry along trajectories similar to those taken by the Space Shuttle, it appears that engineers can put sharper edges on space vehicles. Sharp-body designs offer reduced drag and enable craft to reenter the atmosphere from any orbit and land at any location.


Symposium explores geometries of motion generation, control

A growing body of techniques employing dynamic systems and geometric mechanics is entering the world of motion controls. This was underscored in a symposium held at the National Academy of Sciences in Washington, DC. Proceedings of the symposium are now in print. The report covers several areas including robotic movement, motor miniaturization, and motion engineering. One paper is by Roger W. Brockett, professor in the Division of Applied Science at Harvard University. "In the not too distant future," he writes, "we expect to see some of these ideas being applied to new problems in biological motion control, mechanical design, electronics, and in areas we cannot yet anticipate." You can get copies of the report, Motion, Control, and Geometry (ISBN 0-309-05785-X), by writing to the Board on Mathematical Sciences, National Research Council, 2101 Constitution Avenue, NW, Washington, DC 20418.

Outsourcing is a fad

Outsourcing is a fad

Chambersburg, PA--Tour the foundry of TB Wood's in this historic Civil War town, and you'd swear you're in the heart of Rustbelt America. Thirty-ton channel furnaces glow with fiery molten iron, while molding machines and CNC milling centers churn out finished parts like giant drive wheels for coal crushers. You would never guess that the same company also makes products as diverse as AC and DC drives, softstarts, brakes and clutches, V belts and synchronous drives, and a full line of couplings.

In an era when many OEMs and OEM suppliers are farming out design, TB Wood's prides itself in creating a growing line of power transmission products and exploring new technologies, such as the patented Dura-Flex(R) coupling that won Plant Engineering's Product of the Year award this year. It's an ambitious philosophy for a comparatively small company that went public early in 1996.

"Outsourcing is a passing fad," says TB Wood's President Michael Hurt, who came to the company in 1991 after 23 years with Torrington. "We believe we must control our core manufacturing in-house." Over 30% of sales come from internally developed products introduced since 1992.

With strong roots in the mechanical side of power transmission dating back to 1857--the company produced some of the nation's first drive belts for factories--TB Wood's didn't flinch from designing its own line of motor drives five years ago. Now that product line accounts for 30% of the company's sales, which totaled $102 million in 1996. Three years from now, Hurt expects electronics to represent half of the sales volume. In the process, the company has made heavy investments in equipment for surface mount components, testing, and printed circuit board coating applications.

Why all the vertical integration? "It insures quality and speeds time to market," says Executive Vice President Michael Iversen.

Yet, true to its heritage, TB Wood's prides itself in approaching customers for its electronic products from a mechanical engineering perspective. The company designs its drives to be rugged (many are NEMA 4 rated), easy to install, and easy to maintain. The company's design and application engineers start with the motion to be controlled. For example, with the Power Mod line of inverters, Wood's can remove excess functionality--say, a heat sink--to meet the specific needs of OEMs. That means more horsepower at less cost.

In another example, the company has just introduced a product that integrates the inverter into the end of a motor--instead of on the top as in many designs today. This concept changes only the length of the motor, leaving the standard frame size unaffected. Another benefit: better motor life by eliminating long wire runs from the controller.

Meanwhile, the line of inverters has expanded to range from micro designs for 20 hp motors all the way up to high-performance models with ratings up to 700 hp. Wood's also has developed inverters targeted for special niche markets, such as heating, ventilation and air conditioning.

What do engineering customers think about TB Wood's broad-based approach to providing power transmission solutions? Sales have doubled in the last five years, and Hurt is predicting another doubling in the next three years. Acquisitions will deliver some of that growth, but Hurt believes strongly in leveraging the strength of the company's home-grown talent to develop, produce, and market its new products.

Rather than have its employees "chase rainbows elsewhere" the focus is on providing them with incentives to stay. Like the man said, "Outsourcing is a fad."

Editorial

Editorial

Bidding wars.

  • Fancy dinners.

  • High salaries.

  • Signing bonuses.
    They were the norm during this year's recruiting season, where managers and other suits treated prospective stars like royalty, all in an effort to lure them onto the team.
    Not the basketball or football team. The engineering team!
    Officials from several college campuses report that 1997 was one of the biggest years ever in terms of corporate recruitment activity. "We had more than 700 companies here talking to graduates," says Carole Ferrari, of the Massachusetts Institute of Technology. "It was our busiest year of at least the last five," she adds.
    So many companies wanted to talk to graduates that Lance Choy, of the Stanford University career planning and placement center, told The San Jose Mercury News the school had to turn away 300 to 400 companies for lack of space.
    Recruiting activity was so intense at the University of California at Davis that one professor told the paper he began including in his class instructions on how to deal with bidding wars.
    And how high were the bids this year? Consider this: At MIT, the average offer to new mechanical engineering baccalaureates was $43,700. Those earning doctorates were looking, on average, at offers of $70,900. Graduates of the school's electrical engineering program received salary offers that averaged $45,300 for a bachelor's degree.
    Not bad, considering that the average salary of respondents to this year's Design News career and salary survey is $55,000.
    The reason for the recruitment rush is Economics 101: supply and demand.
    Nationwide, unemployment is down. The economy is growing, yet, according to the U.S. Department of Education, the number of engineering graduates dropped 18 percent between 1986 and 1994. It's a seller's market.
    That reality, plus the many challenging design projects in the aerospace, automotive, medical, and other industries, makes this a great time to be an engineer.