DIESEL CLEAN-UP EFFORT EARNS HIGH MARKS
By Harry Hutchinson

A study of emissions by heavy-duty diesel engines has found that newer designs are not only far cleaner on many counts than older ones, but are also performing better than federal environmental rules require. The results come from the first phase the Advanced Collaborative Emissions Study, or ACES, a five-year project being conducted by the Coordinating Research Council and the Health Effects Institute.

Phase 1 compared emissions of 2007 model-year engines to those of 2004 models. 

Results of laboratory tests found that emissions of most major pollutants by the 2007 engines were reduced as much as 90 percent compared with engines made three years earlier. Rules issued by the Environmental Protection Agency set a series of emissions-reduction mandates to be met by heavy-duty diesel engines of the sort used in large trucks and buses. Significant emissions reductions were required at the start of 2007.

The Southwest Research Institute tested four different 2007 model engines, all considered heavy heavy-duty diesels. They were a CAT C13, Cummins ISX, DDC Series 60, and Mack MP7. According to the report, among their emission-control technologies, the engines were equipped with a diesel oxidation catalyst followed by a wall-flow catalyzed diesel particulate filter, or with a catalyzed particulate filter with a means of active regeneration via exhaust fuel injection or a burner.

Data for 2004 engine performance were taken from previous studies at SWRI.

The tests found that the newer engines’ emissions of fine particulate matter were about 99 percent lower than levels from 2004 heavy-duty diesels and nearly 90 percent lower than the 2007 rules demand. Emissions of carbon monoxide, hydrocarbons, and a number of unregulated, so-called air toxics were also more than 90 percent lower than the 2004 levels, and regulated emissions were substantially below legal requirements. In addition, emissions of nitrogen oxides were approximately 70 percent lower than in 2004 technology, and 10 percent below required levels. Another approximately 80 percent reduction in NO_x emissions is required for engines sold after Jan. 1, 2010.

The full text of the 158-page report on ACES Phase One is available through a link at the Coordination Research Council’s home page, www.crcao.org.

ACES is supported by government and private sector sponsors, including the U.S. Department of Energy, U.S. Environmental Protection Agency, California Air Resources Board, Engine Manufacturers Association, American Petroleum Institute, and manufacturers of emission control equipment.

The Health Effects Institute is funded largely by the U.S. Environmental Protection Agency and the international motor vehicle industry to research the health effects of air pollution. HEI is handling the overall design and management of ACES, and the laboratory testing of health effects. All emissions characterization for ACES is being overseen by the Coordinating Research Council. The CRC is a non-profit corporation supported by the petroleum and automotive industries and by government agencies. It conducts research aimed at optimizing the combination of automobiles and petroleum products.

A second phase to test the 2010 engines is being planned. According to HEI, detailed short- and long-term laboratory health testing of emissions from one of the four representative engines tested in Phase 1 is getting under way at the Lovelace Respiratory Research Institute in Albuquerque. Initial results are expected next year.           

S STAMP FOR SOLAR STEAM BOILER
By Jeffrey Winters

Steam boilers might not seem at first like cutting-edge technology. ASME’s Boiler and Pressure Vessel Code was first published in 1915, and products constructed in accordance to that code have been affixed with stamps since shortly thereafter. But in June, ASME awarded the Society’s S Stamp for the manufacture of some very futuristic-seeming boilers: ones that contain solar-heated steam.

Ausra, the manufacturer of solar thermal power systems, received the S Stamp certification for the company’s industrial steam power boilers. The company, based in Mountain View, Calif., is also accredited to use the NB stamp of the National Board of Boiler and Pressure Vessel Inspectors.

“The S Stamp is the hallmark in the industry of acceptance,” said Tom Bartolomei, senior vice president for business development at Ausra. “Utilities and industrial facilities that operate boilers will recognize that Ausra knows what it takes to make a quality product,”

The technology that Ausra employs is different from the familiar photovoltaic cells, which directly convert sunlight into electricity. Instead, the company erects large arrays of long, nearly flat mirrors which focus sunlight onto a narrow conduit running more than 40 feet above the ground. The concentrated sunlight heats water-filled tubes in the conduits to several hundred degrees, and this steam is used for process heat or to drive a turbine to generate electricity. 

The company had pursued the certification of its steam boilers for about a year. Indeed, the company realized from the beginning that it was an important step in the progress of its business. “When you look at the pressure from the financial markets today, an independent engineer that has to sign off on a new development is going to look favorably on the fact that we have an S Stamp,” Bartolomei said. “It’s really going to help with our marketing.”

One of the directions Ausra is pushing forward in is using its compact solar thermal arrays to generate steam for uses other than electrical generation. One such application is desalination, Bartolomei said; a multistage flash distillation unit requires a substantial amount of steam to vaporize brine. Typically, the steam is generated by burning oil or other fossil fuels, but solar-generated steam could do the job just as efficiently.

The company is also looking to sell its units to utilities to help complement fossil fuel-powered generating stations. The first Ausra solar thermal station, built in New South Wales, Australia, runs as part of a hybrid power plant.

“Combined-cycle gas turbines have a power loss as the air heats up on hot summer days,” said Bill Conlon, Ausra’s vice president for engineering. “That dovetails perfectly with the solar capacity that’s available from our steam generators.”

RUNNING ON FEATHERS
By Jean Thilmany

Cars of the future just might carry chicken feathers instead of a gas tank.

Researchers in Delaware said they’ve developed a new hydrogen storage method based on carbonized chicken-feather fibers.

The method can hold vast amounts of hydrogen, a promising but difficult-to-corral fuel, and do it at a far lower cost than other hydrogen storage systems under consideration, said Richard Wool, professor of chemical engineering and director of the Affordable Composites from Renewable Resources program at the University of Delaware in Newark.

And it could eventually help overcome some of the hurdles to using hydrogen fuel in cars, trucks, and other machinery, Wool said.

The fibers contained within chicken feathers are mostly composed of keratin, a natural protein that forms strong, hollow tubes. When heated, this protein becomes more porous, increasing its surface area, Wool said.

The result is carbonized chicken-feather fibers, which can absorb as much—or perhaps more—hydrogen than carbon nanotubes or metal hydrides, two other materials being studied for their hydrogen storage potential, Wool said.

But chicken feathers are cheap and plentiful, unlike the nanotubes and metal hydrides, he added.
Wool estimates that to travel 300 miles on hydrogen stored in carbonized chicken feather fibers, a car would need a 75-gallon tank. He says his team is working to improve that range.

In addition to hydrogen storage, Wool and his colleagues are working on ways to transform chicken-feather fibers into a number of other products including hurricane-resistant roofing, lightweight car parts, and computer circuit boards. 

GRADUATE ENGINEERS: MORE MULTINATIONAL AND DIVERSE
By Alan S. Brown

U.S. enrollment in graduate-level engineering programs increased 5.9 percent in 2007, according to the latest data from the National Science Foundation. The data also show U.S. graduate programs becoming more diverse as universities enroll more foreign-born, female, and minority students.

The largest percentage increases in enrollment were in civil engineering, up 11.6 percent to 19,867 students, and in biomedical engineering, which rose 6.2 percent to 6,904 graduate students (more than twice as many as in 2000). Mechanical engineering graduate students increased 2.5 percent to 18,347.

Taken together, science and engineering graduate programs grew 3.3 percent in 2007, nearly twice as fast as in 2006 and the largest increase since 2003. Total graduate science and engineering enrollment reached 516,199 in 2007, 71 percent full-time students. Engineering accounted for 26 percent of enrollment; science, 74 percent.

Among the 72 percent of graduate students who were U.S. citizens or permanent residents, 52 percent were men and 48 percent women. (Men outnumbered women two-to-one among foreign students with temporary visas).

Minorities represented an increasing proportion of the total. Among graduate science and engineering students, 9 percent were Asian, 8 percent black, 7 percent Hispanic, and 10 percent “other” or multiracial. White students accounted for 66 percent of the graduate students.

With the exception of 2001-03, when more U.S. citizens enrolled in engineering, most of the changes in engineering enrollment have come from changes in foreign enrollment, according to the National Science Foundation.           

CLIMATE REPORT CITES CHANGES
By Alan S. Brown

Climate change has already begun to reshape the United States, according to a major study by 13 federal agencies and by experts at several major universities and research institutes.

The report, Global Climate Change Impacts in the United States, finds that global warming is unequivocal and primarily human-induced. Global temperature has increased over the past 50 years, due mostly to human-induced emissions of heat-trapping gases.

According to the report, climate changes are already visible in the United States and its coastal waters. The effects include more frequent heavy downpours and flooding, rising temperature and sea level, earlier snowmelt, and alterations in river flows.

The report expects these changes to increase, though their impact will vary by region. Flooding, for example, will become more common in the northern and eastern United States, but in the West, the reduction of the mountain snowpack will limit water supplies, especially in the summer. Heat waves will become more frequent and intense, and pose threats to health and quality of life in the Southwest.

Coastal areas will have to cope with rising sea levels and, perhaps more significantly, much higher storm surges. They must also deal with rising ocean temperatures and acidification that threaten coastal fisheries. As temperatures rise, farmers will have to cope with a new spectrum of warm-weather pests and diseases, as well as water stress.

The report is similar to a draft issued by the Bush Administration in 2007; environmental groups had to sue the government to release that document. The Intergovernmental Panel on Climate Change sought to play down any controversy by noting that the 190-page report is a consensus product that spanned two presidential administrations and transcends political leanings or biases.

Scientists inside and outside of government reviewed the report, which includes information more recent than that incorporated into the last major report on global climate change released by the Intergovernmental Panel on Climate Change.

The report is available on the Web site of the U.S. Global Change Research Program, www.globalchange.gov.                       

BRIEFLY NOTED

Simmetrix Inc. of Clifton Park, N.Y., which makes component software for integration with computer-aided design packages, has released Simulation Modeling Suite 7.0, with modeling functionality for fracture mechanics. Modules within the suite provide access to modeling for insertion of crack geometry and modified crack geometry due to crack propagation. /// Tempco Electric Heater Corp., a manufacturer of electric heating elements, temperature sensors, temperature controls, and turnkey process heating systems, has received ISO-9001 quality management system certification. /// Mechdyne Corp. of Marshalltown, Iowa, has released its Conduit V2.6, a real-time graphics distribution software that displays desktop applications in 3-D stereo and virtual reality environments.