new laser technique for nonsurgically diagnosing certain cancers has been developed by scientists from ORNL and the Thompson Cancer Survival Center in Knoxville, Tennessee. The research team, led by Tuan Vo-Dinh of ORNL's Health Sciences Research Division, and Bergein Overholt and Masoud Panjehpour, both of the cancer center, has informally dubbed the technique an "optical biopsy" because laser light is used to determine whether a tumor is malignant or noncancerous.
The researchers say the new method could change the course of medicine in diagnosing certain tumors because no tissue must be removed and the diagnosis is made almost immediately. In more than 200 tests of over 50 patients at the Thompson Cancer Survival Center, the method has accurately diagnosed almost all tumors of the esophagus.
Conventional biopsy of such tumors requires the use of a pincer-tipped cable to physically remove tissue for analysis. Such a surgical procedure entails recovery time for patients and an expensive, time-consuming laboratory analysis to determine malignancy.
In the new method, instead of the biopsy "pincer" cable, a fiber-optic cable is inserted in the biopsy channel of an endoscope, an instrument for visualizing the interior of a hollow organ. Laser light is directed through the cable's optical fibers onto the tissue. The tissue absorbs the laser light and, depending on the light's wavelength, reemits it as a fluorescent "glow," which is spectrally analyzed. Using a special data analysis method, the researchers discovered that the spectral "fingerprint" of a malignant tumor can be distinguished from that of a noncancerous tumor This method can be used to diagnose some cancers rapidly without surgery, thus improving the effectiveness and decreasing the cost of cancer diagnosis and therapy.--Wayne Scarbrough
Energy Savings for Low-Income Households
In Wisconsin, an elderly woman watches workers blow high-density cellulose insulation into the wall cavities of her home and install a high-efficiency gas furnace. In Ohio, a widowed mother of four young children observes a series of "blower-door tests" that tells the weatherization crew when to stop sealing cracks and crevices in her leaky house. In Georgia, a disabled veteran looks forward to seeing his front yard through new storm windows and wonders how much lower his fuel bills will be.
All live in low-income households. Most importantly, they are participants in the Department of Energy's Weatherization Assistance Program, the nation's largest energy conservation program and one of its oldest. ORNL has played an important role in evaluating this program.
The Weatherization Assistance Program has been operated by DOE since 1976 to increase the energy efficiency of dwellings occupied by low-income households. Its goals are to reduce their energy consumption, lower their fuel bills, increase the comfort of their homes, and safeguard their health. It targets vulnerable groups, including the elderly, people with disabilities, and families with children.
According to the U.S. Department of Health and Human Services (HHS), the average low-income family spends 12% of its income on residential energy, compared with 3% for the average U.S. family. The program helps pay for the conservation measures that low-income families need but cannot afford. It also provides an infrastructure of rules and guidelines and a network of more than 1100 agencies located across the nation that can deliver weatherization services with funding from a variety of sources in addition to DOE. This "leveraging" is an important strength of the program.
Between 1978 and 1989, DOE provided 45% of the $4.4 billion used to weatherize the homes of low-income households in the United States. Other sources of federal funding for weatherization are the Low-Income Home Energy Assistance Program administered by HHS and Petroleum Violation Escrow, or "oil overcharge," monies. Utilities also fund low-income household weatherization.
In 1990 DOE initiated a nationwide evaluation of its Weatherization Assistance Program, with assistance from ORNL. One finding is that more homes were weatherized, more money was spent, and more energy was saved in the North than in the South, in part because DOE allocates its weatherization funds more to areas that have greater heating than cooling needs. Overall, preliminary results indicate that the program saves energy, improves homes, and provides jobs.
Marilyn Brown and Linda Berry, both of ORNL's Energy Division, led a team that collected and analyzed data from agencies, utilities, households, and the National Oceanic and Atmospheric Administration to determine the costs of conservation measures, the amount of energy saved, other benefits of the program, and the cost effectiveness of the program in three regions of the United States--cold climate, moderate climate, and hot climate. They examined almost 15,000 single-family and small multifamily dwellings weatherized under DOE guidelines during 1989 and compared them with more than 3600 control homes.
The ORNL researchers found that the measures installed and procedures used in 1989 varied widely among local agencies administering the DOE program and that the differences across climate regions were quite pronounced. "In cold climates," Brown says, "we noted high installation rates for ceiling, wall, and floor insulation and space- or water-heating tuneups, repairs, or replacements, but we observed low installation rates for storm and replacement windows and new doors. Also, integrated energy audits, blower-door testing to assist air sealing, and space-heating diagnostics were used more often in the cold climate region than the other regions."
In the moderate-climate region, the researchers found higher installation rates for storm windows, space-heating measures, and air-leakage control measures such as weatherstripping and caulking. In the hot-climate region, installation rates were lower for wall insulation and space and water heating but higher for replacement windows and doors. Unlike the cold-climate region, integrated energy audits, blower-door testing, and space-heating diagnostics were rarely used in the hot-climate region.
Studies suggest that integrated audits, insulation, and space-heating retrofits and replacements result in the greatest energy savings, and these are the measures emphasized by the local weatherization agencies in the cold climate. "In contrast," Brown says, "housing rehabilitation measures that cannot be expected to significantly lower energy usage are emphasized more by agencies in the hot region, reflecting the more dilapidated state of low-income housing in the South."
The program clearly saves energy, the ORNL researchers found. Weatherized gas-heated homes used 13% less electricity overall and 18% less gas for space heating than they consumed before weatherization. Weatherized electrically heated homes used 12% less electricity overall and 36% less electricity for space heating. They calculated that weatherization in 1989 of 198,000 single-family and multifamily homes by the program's 1100 local agencies saved the equivalent of 600,000 barrels of oil during 1990-91, or a projected 12 million barrels of oil over the 20-year lifetime of these conservation measures.
In 1989 the average direct cost per dwelling of weatherization was $1050, but 8% of the homes had installation costs under $300 and 9% had expenditures of more than $1800. An additional $500 on overhead and program administration is spent, on average, per weatherized home.
The ORNL researchers were surprised to find no discernible energy-savings benefit from use of the blower-door test to determine if a home is properly sealed to minimize heat losses. This finding is attributed to the fact that blower doors were just being introduced into local agency procedures in 1989 (see photograph at right).
"Today blower doors are used more extensively, and most state agencies offer training in their use," Brown says. "In fact, low-income weatherization agencies have been leaders in the use of blower doors nationwide. Although blower doors may have been ineffectively used in 1989, such problems are undoubtedly less characteristic of the program today."
Brown and Berry also estimated the value of the program's nonenergy benefits. They include environmental benefits from reduced use of fuel, employment of workers who weatherize dwellings, federal taxes generated from employment, avoided costs of unemployment benefits, enhanced property values for homes, extended dwelling lifetimes, and a decrease in home fires caused by faulty heating equipment.
The researchers found that the Weatherization Assistance Program is a cost-effective government investment; its benefits exceed its costs based on each of the three perspectives employed (installation, program, and societal) in which various benefits and costs are weighed. The program is also cost effective for two types of dwellings from all three perspectives.
"Weatherization of detached single-family and small multifamily dwellings was cost effective from all three perspectives," Berry says, "but weatherization of mobile homes was not cost effective when the definition of benefits is limited to energy savings--the program perspective.
"Perhaps the most striking result of our evaluation," Berry adds, "is the tremendous diversity among local weatherization agencies. Some weatherize 15 homes in a year, whereas others weatherize thousands. Some agencies achieve savings of 30 to 40% of preweatherization energy consumption, others produce no measurable savings. Some employ state-of-the-art procedures, leverage a wide variety of financial and technical resources, and perform sophisticated self-evaluations designed to constantly improve their performance. Others follow the same procedures year after year, do not evaluate their impacts, and rely only on DOE funding."
The United States still has 24 million households that are eligible for participation in DOE's Weatherization Assistance Program. Brown says that, to meet these needs, she would like to see more partnerships and a pooling of resources among utilities, DOE's Office of Energy Efficiency and Renewable Energy (which funded the ORNL study), energy service companies, and community action agencies that have experience in providing weatherization services.--Carolyn Krause
ORNL Plays Large Role in ITER Fusion Project
ORNL is playing a major role in development of the International Thermonuclear Experimental Reactor (ITER), which is the largest international scientific project ever attempted. The goal of the multibillion-dollar project is to demonstrate the scientific and technological feasibility of fusion energy.
Participants include the European Community (Euratom), Japan, the Russian Federation, and the United States. The project is being conducted under the auspices of the International Atomic Energy Agency.
Charles C. Baker, a staff member of ORNL's Fusion Energy Division and an editor of the Fusion Engineering and Design journal, is manager of the U.S. ITER Home Team. It is one of four teams working on the engineering design of the ITER with the Joint Central Team. The central team is based in San Diego, California; Garching, Germany; and Naka, Japan.
The ITER will be a tokamak, a doughnut-shaped device in which the hot fusion plasma--a mixture of ions and electrons--will be confined by superconducting magnets. No electricity will be produced at the ITER.
The conceptual design of the ITER was completed in 1990. Engineering design work, under way since 1992, is expected to be complete in 1998. Construction is planned for 1998Ð2005, and operation should begin in 2005.
Baker says the ITER project will help the United States meet its fusion goals. "It will advance fusion science and technology, increase industrial involvement in fusion technology, take advantage of international collaboration to spread out costs, bring the world's best minds in fusion together, and establish a model for other megascience projects."
ORNL materials researchers under Arthur Rowcliffe and Everett Bloom, both of the Metals and Ceramics Division, are working on developing advanced high-performance materials for fusion reactors. They include austenitic and ferritic stainless steels, carbon-fiber composites, and vanadium alloys.
ITER officials are debating whether to include advanced materials in the tokamak design. Baker says the ITER design will probably emphasize use of the lower-performance materials such as austenitic stainless steels because their properties are well known.
ORNL work for the U.S. Home Team, including the materials development, is managed by plasma physicist Nermin Uckan of the Fusion Energy Division. She is also in charge of ITER-related design studies on plasma performance for the U.S. Home Team. David Lousteau of Energy Systems' Engineering Division is deputy manager. Other ORNL work for the ITER includes remote handling, plasma technology development, and reactor engineering design.
"There is little doubt that we can create plasmas to meet requirements for heat and power production," Baker says. "The key to fusion success--and our greatest challenge--is to integrate engineering components and technologies. The dilemma for fusion researchers is that, unlike for fission, test reactors must be built as large as the future commercial ones to demonstrate that practical fusion energy is possible. However, a potential advantage for fusion power plants will be their environmental and safety features."--Carolyn Krause
Largest Reactor Vendors in Europe and Japan
Until 1980 most nuclear power plants operating throughout the world were "made in the U.S.A." Four vendors--Westinghouse Electric, General Electric, Babcock & Wilcox, and Combustion Engineering--had supplied 80% of the world's commercial reactors in the 1960s and 1970s.
Since 1980, more than 70% of the western world's commercial reactors have been provided by vendors in Europe and Japan. They are Framatome of France; Siemens of Germany; Asea Brown Boveri of Sweden and Switzerland; and Mitsubishi, Hitachi, and Toshiba, all of Japan.
What is the future of the nuclear industry? Who will be the chief vendors? What will be their future reactor products? Who will be their customers? These questions have been explored in a study conducted by two ORNL researchers--Charles W. Forsberg of the Chemical Technology Division and Larry Hill of the Energy Division, together with William J. Reich of the Chemical Technology Division and William J. Rowan, a consultant.
According to the report, nuclear power suppliers are no longer organized along single-company, national lines. "Since 1980, vendors are using three organizational structures to increase sales and reduce risk.
"First, international corporations such as Asea Brown Boveri--the largest industrial equipment manufacturer in the world--own multiple reactor vendors in multiple countries.
"Second, international joint ventures between multiple reactor vendors have been created to sell, design, and build nuclear power plants. The largest such joint venture and the dominant European group is Nuclear Power Incorporated (NPI), which is controlled by Siemens and Framatome.
Third, international consortia for joint sales and product development have been created. An example is the Hitachi-General Electric-Toshiba group.
What changes can be anticipated in the nuclear industry in the 1990s? Because of historical business relationships, the report's authors expect that NPI partners Siemens and Framatome will be major suppliers in Eastern Europe and the former Soviet Union. They also believe that the biggest future impact on the international market will be the Japanese vendors.
"Japan has the largest domestic nuclear power construction program in the 1990s," Forsberg observes, "and it is now beginning to export nuclear power equipment."
According to the report, a vendor capability is being developed in the People's Republic of China.
Although many types of reactors have been developed, the report states that the market will continue to be dominated by three reactor types--pressurized-water, boiling-water, and Canadian heavy-water reactors.
Besides the utilities in 28 countries that now operate or are building nuclear power plants, future customers may include 25 countries with economies large enough to support such facilities. Most future reactor sales are expected in countries along the Pacific Rim, such as Japan, China, Taiwan, South Korea, and Indonesia.
"These countries," Forsberg says, "have a larger demand for nuclear power plants than other nations because of a combination of factors. They have limited indigenous energy resources, rapid growth in electricity demand, and better acceptance of nuclear power."--Carolyn Krause
Researchers Track Traffic Trends
A new report produced by ORNL researchers Patricia Hu and Jennifer Young of ORNL's Energy Division for the U.S. Department of Transportation paints an increasingly crowded picture of life on America's highways. In fact, their work shows rush hour has become nearly an all-day affair, stretching from dawn until dusk, with only a brief midmorning lull.
The report, Nationwide Personal Transportation Survey, highlights a number of reasons for this increased traffic. More drivers are driving more cars more often than ever before. Society itself is also changing.
More women are working outside the home, and more women are getting drivers' licenses. They still don't drive as much as men, but they're closing the gap. Teenagers are driving more too--nearly twice as much as they did in the 1960s. Retirement-age folks are also driving 40% more miles per capita than in 1969.
"You can't really compare driving habits people had 30 years ago with the way we drive today," says Hu. "Thirty years ago, people could walk to the store, to school, even to work. We can't do that anymore."
Hu and Young analyzed travel data gathered through a random telephone survey of over 22,000 U.S. households. The report also tracks information on vehicle ownership, household travel patterns, and other travel-related information for 12 months before the survey. The nationwide travel survey is conducted by the U.S. Department of Transportation every 5 years.
The next survey will be conducted in 1995, and, despite the comprehensive nature of this survey, Hu would like to do a few things differently the next time. "We would like to study the movement of people," she says, "to determine where they are going and why. I also think the issue of telecommuting--working at home and communicating with the office by computer--should be addressed."
Fuel consumption is another area Hu would like to see studied in the 1995 survey. Current figures are based on the year, make, and model of cars reported in the survey, along with Environmental Protection Agency mileage estimates. "But that doesn't tell the whole story," says Hu. "To associate travel habits with fuel economy, we need to get fuel economy figures for individual cars."
You'd think that a never-ending rush hour, rising gasoline taxes, and a growing hole in the planet's ozone layer would have the public clamoring for greater access to transportation alternatives, such as buses and trains.
"We asked people about that," says Hu. "They say it's more convenient to use their cars."--Jim Pearce
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