March 29, 2007, 10:00 PM CT

Construction Strategies to Avoid Progressive Collapse

The 1995 terrorist attack on the Oklahoma City Alfred P. Murrah Federal Building heightened concern on the vulnerability of multi-story buildings to "progressive collapse," the spread of an initial local structural failure by chain reaction that results in the collapse of an entire structure or a disproportionately large part of it. The National Institute of Standards and Technology (NIST) recently issued a guide to help owners, engineers and building officials avoid such collapses through prudent planning and design of structures. The guide also summarizes national and international best practices for designing buildings resistant to progressive collapse of buildings.

The report, Best Practices for Reducing the Potential for Progressive Collapse in Buildings, argues that eventhough no building system can be engineered and constructed to be absolutely risk-free, risk-informed assessment and decision-making can reduce the risk of progressive collapse. As per the researchers, engineers must not simply work to the minimum requirements of the building code; they need to consider ways to improve structural integrity and robustness to accommodate local failures.

As per NIST engineers, hazards that increase the risk of local structural failures that, in turn, can lead to a partial or complete progressive collapse include design and construction errors, fire, gas explosion, the transport and storage of hazardous materials, vehicular collision, and bomb explosions......... Posted by: Tom      Read more         Source

March 27, 2007, 8:47 PM CT

Seventies oil crisis was a 'perfect storm' for U.S.

During the energy crisis of the 1970s, a number of people believed that fully loaded tankers lingered just offshore, waiting for oil prices to go up.

It was an era in American history, said Meg Jacobs, Class of 1947 Career Development Associate Professor, when many political, global and social events came together to create a perfect storm.

Jacobs spoke at a Science, Technology and Society (STS) colloquium March 19. A political historian, Jacobs said she is writing a book on the energy crisis because it provides a good example of how chaos can erupt when there is a disconnect between what citizens expect and how government reacts.

For anyone who owned a car in 1973, it's hard to forget the long lines at pumps, the "sold out" and "no gas today" signs, the rationing and the gas station attendants who carried guns for self-protection.

What caused the crisis was the Organization of Arab Petroleum Exporting Countries' (OAPEC, which was the Arab members of OPEC plus Egypt and Syria) embargo on shipping petroleum to nations that supported Israel in the Yom Kippur War between Israel, Syria and Egypt.

About the same time, OAPEC members agreed to use their leverage over the world price-setting mechanism for oil to quadruple world oil prices, after attempts at negotiation with the major oil companies failed......... Posted by: Tom      Read more         Source

March 27, 2007, 8:19 PM CT

A Mathematical Solution for Another Dimension

Ever since 1887, when Norwegian mathematician Sophus Lie discovered the mathematical group called E8, researchers have been trying to understand the extraordinarily complex object described by a numerical matrix of more than 400,000 rows and columns.

Now, an international team of experts using powerful computers and programming techniques has mapped E8--a feat numerically akin to the mapping of the human genome--allowing for breakthroughs in a wide range of problems in geometry, number theory and the physics of string theory.

"Although mapping the human genome was of fundamental importance in biology, it doesn't instantly give you a miracle drug or a cure for cancer" said mathematician Jeffrey Adams, project leader and mathematics professor at the University of Maryland. "This research is similar: it is critical basic research, but its implications may not become known for many years".

Team member David Vogan, a professor of mathematics at the Massachusetts Institute of Technology (MIT), presented the findings today at MIT.

The effort to map E8 is part of a larger project to map out all of the Lie groups--mathematical descriptions of symmetry for continuous objects like cones, spheres and their higher-dimensional counterparts. Many of the groups are well understood; E8 is the most complex......... Posted by: Jaison      Read more         Source

March 25, 2007, 9:14 PM CT

Late Registrants More Likely to Vote

Later is better" when it comes to voter registration in national elections, according a new study of voter participation in the 2000 presidential election.

People who register to vote closer to registration deadlines are much more likely to vote on Election Day than are people who register earlier in an election year, according to the study conducted by political scientists from the University at Buffalo, University of Maryland and University of Texas.

"It's a very interesting pattern," says UB researcher Joshua J. Dyck, Ph.D., assistant professor of political science. "For political campaigns focused on get-out-the-vote efforts, the takeaway message is this: you'll get more bang for your buck if you focus on the narrow window close to the registration deadline.

"That's where we see a huge surge in voter registration and those people are much more likely to turn out to vote".

Dyck's co-researchers were James G. Gimpel, Ph.D., professor of government at University of Maryland, and Daron R. Shaw, Ph.D., associate professor of government at University of Texas.

The researchers focused on voter registration and voter turnout in large counties in six states during the 2000 presidential campaign. These included battleground states Florida, Iowa and New Mexico, as well as Kentucky, Nevada and North Carolina. The sample included more than 400,000 registered voters. The deadline for voter registration is about 30 days before an election in most states......... Posted by: Jaison      Read more         Source

March 21, 2007, 9:12 PM CT

Health Of New Composite Military Missiles

Engineers at Purdue University have designed and tested a "structural health monitoring" system to detect flaws that could hinder the performance of new types of military missiles made of composite materials instead of metal.

Missiles are sometimes damaged when struck by rocks and debris kicked up by helicopter rotors or when mishandled during shipping or maintenance.

Unlike missiles made of metallic alloys, which often show external signs of damage such as cracks or dents, damage in the new "filament wound" composite materials may not reveal telltale signs, said Douglas Adams, an associate professor of mechanical engineering.

The new monitoring system uses a mathematical model to pinpoint the location and severity of impacts based on vibration data collected by a sensor called a triaxial accelerometer.

"We have shown that 98 percent of the time we can detect, locate and quantify the force of impacts," Adams said. "This information is very useful because it enables the monitoring system to determine within seconds whether an impact is beyond the design threshold and is great enough to likely cause serious damage".

Findings will be detailed in a research paper to be presented Wednesday (March 21) during an International Society for Optical Engineering conference. The conference, Smart Structures and Materials and Non-Destructive Evaluation and Health Monitoring, takes place through Thursday (March 22) in San Diego. The paper was written by Adams, graduate student Nick Stites, undergraduate student Carlos Escobar, and doctoral student Jonathan White, all in Purdue's School of Mechanical Engineering; and Matt Triplett, an engineer from the U.S. Army's Aviation and Missile Research, Development and Engineering Center......... Posted by: Tom      Read more         Source

March 21, 2007, 5:02 AM CT

Cutting hours for overemployed may boost well-being

If overemployed workers were encouraged by employers to cut back to their level of preference, it could well have a profound impact on employees' well being, as per a Penn State researcher.

Lonnie Golden, associate professor of economics at Penn State's Abington Campus in greater Philadelphia, said empowering the 7 percent of workers who claimed in a 2001 U.S. Current Population Survey that they would like to cut back on their hours and income to do so, might create some work and income for the 23 percent of the work force that is underemployedthose who would like more work and incomeas well as the unemployed. It would also free up time for the overemployed to pursue endeavors other than work, which could lead to improved work-life balance and quality of life.

"The unemployment rate is under 5 percent now, which is pretty good. However, if 7 percent of the workforce feels as if they are working more hours than they would like, and some folks have no jobs or are seeking more work hours, then something is not functioning as well as it could in the labor market," he said. "It would benefit all employees if they could work closer to the amount of hours they desire, and in the long run, it would likely be beneficial for employers as well, in terms of greater efficiency and employee retention"......... Posted by: Mac      Read more         Source

March 19, 2007, 10:31 PM CT

Pinpointing Traffic Accident "Hotspots"

Ohio State University researchers have created software that can identify traffic accident hotspots on state roadways.

The software is publicly available and can be adapted for use by any state, said Christopher Holloman, associate director of the Statistical Consulting Service in Ohio State's Department of Statistics. Currently, the Ohio State Highway Patrol is using it to help position its cruisers during major holidays.

"We can make predictions for every major roadway in Ohio, under all possible road conditions, for every hour of the day, for every day of the week," Holloman said.

The software relies on reports of injuries and fatalities from the highway patrol, and incorporates statistics about what makes accidents happen.

Common accident causes such as speeding or alcohol consumption are fairly easy to model using computers, Holloman explained. Others -- such as when a driver will be distracted by a cell phone -- are impossible. So the software makes general forecasts.

"Everyone would love to be able to predict exactly where and when the next crash would be, but there are just too a number of factors involved, and too much randomness to do that," he said. "We can confidently make broad statements, like whether a particular piece of roadway is riskier at a particular time"......... Posted by: Jim      Read more         Source

March 19, 2007, 5:16 AM CT

Virtual racing games linked to risk taking

Psychology experts have taken the "media priming" effects of popular video console and PC-based games on the road, finding that virtual racing seems to lead to aggressive driving and a propensity for risk taking. Extending previous findings on how aggressive virtual-shooter games increase aggression-related thoughts, feelings and behaviors, scientists at Munich's Ludwig-Maximilians University and the Allianz Center for Technology observed that of 198 men and women, those who play more virtual car-racing games were more likely to report that they drive aggressively and get in accidents. Less frequent virtual racing was linked to more cautious driving.

The findings are reported in the recent issue of the Journal of Experimental Psychology: Applied, which is published by the American Psychological Association.

Linking media priming effects the way virtual aggression can lead to the real thing -- to behavior, a second study observed that men who played even one virtual racing game subsequently took significantly higher risks in critical traffic situations on a computer simulator than did men who played a neutral game. Sixty-eight men were in this study.

Finally, the scientists assigned 83 men to play either typical racing or neutral games on a Sony Playstation. In the racing games, say the authors, "To win, participants had to massively violate traffic rules (e.g., drive on the sidewalk, crash into other cards, drive at high speed)." Those who raced subsequently reported a significantly higher accessibility of thoughts and feelings associated with risk-taking than did those who played a neutral game......... Posted by: Gina      Read more         Source

March 13, 2007, 9:33 PM CT

Videotaped confessions can create bias

Police often videotape interrogations of suspects for use in criminal trials. Video confessions that focus exclusively on the suspect, however, can bias judges and law enforcement officers to consider the suspect's statements as voluntary, as per a new Ohio University study.

In more than 25 percent of wrongful convictions exonerated by DNA testing, innocent defendants made incriminating statements, delivered outright confessions or pled guilty, as per the Innocence Project. Police interrogation tactics - which include exaggerating the evidence against the suspect or implying the suspect could face an extreme sentence - can prompt a suspect to make a false confession, said Daniel Lassiter, an Ohio University professor of psychology.

In videotaped confessions, a number of law enforcement agencies focus the camera on only the suspect. Lassiter's research shows that this practice creates what he calls a camera-perspective bias that leads trial participants to view the confessions as voluntary, regardless of how interrogators obtained them.

In the recent study, reported in the recent issue of Psychological Science, Lassiter and his colleagues from Northwestern University and the American Bar Foundation asked 21 judges and 24 law-enforcement officers to view a videotaped mock confession. The scientists presented participants with different versions of the confession in which the camera focused on only the suspect, only the detective, or both suspect and detective. Participants assessed how voluntarily the suspect confessed in each case......... Posted by: Tom      Read more         Source

March 12, 2007, 9:19 PM CT

Developing Countries' Water And Sanitation Needs

Worldwide, more than one billion people lack access to an improved water source, such as a rainwater collection or dug well, and two billion still need access to basic sanitation facilities, such as a latrine.

By 2015, the international community hopes to reduce by half the number of people without sustainable access to safe drinking water and basic sanitation.

This target for sustainable water and sanitation is just one of the United Nations Millennium Development Goals adopted in September 2000 at the Millennium Summit. These goals serve as the world's time-bound and quantified targets for addressing extreme poverty.

Local communities in the developing world and professional scientists are working to meet this goal. Scientists recently presented their work toward this end at the annual meeting of the American Association for the Advancement of Science (AAAS).

In the developed world, the moment a drop of water hits the ground, it goes into the water system until it becomes wastewater. Then it's treated and put it back into the system.

"We have a large-scale infrastructure in the United States to provide clean water," said Joseph Hughes, chair of the Georgia Institute of Technology School of Civil and Environmental Engineering. "Using our current approach will not provide the rapid fix the United Nations is looking for in developing countries. It would take decades"......... Posted by: Tom      Read more         Source