EPA says greenhouse gases 'endanger' health
By Janet Raloff
Web edition : Friday, April 17th, 2009

The Environmental Protection Agency issued a landmark ruling today. It said that “greenhouse gases contribute to air pollution ... The greenhouse gases that are responsible for it endanger public health and welfare within the meaning of the Clean Air Act.”

Environmental policymakers have been waiting to see whether the Obama administration would issue such an “endangerment” ruling for greenhouse gases. Many public interest groups had asked the Bush administration to do so. And it refused. The Bush administration also prohibited individual states from taking action, arguing that if the feds couldn’t justify such a ruling, the states couldn’t either.

In announcing the endangerment finding today, EPA Administrator Lisa P. Jackson sets in motion steps that could eventually force states to ratchet down their emissions. The new proposal cites not only carbon dioxide as a potential endangering greenhouse gas but also methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. see more...

ultrasonic irrigation

by L. W. M. van der Sluis , M. Versluis , M. K. Wu & P. R. Wesselink 7 December 2006

Ultrasonic irrigation of the root canal can be performed with or without simultaneous ultrasonic instrumentation. When canal shaping is not undertaken the term passive ultrasonic irrigation (PUI) can be used to describe the technique. In this paper the relevant literature on PUI is reviewed from a MEDLINE database search.

Passive ultrasonic irrigation can be performed with a small file or smooth wire (size 10–20) oscillating freely in the root canal to induce powerful acoustic microstreaming. PUI can be an important supplement for cleaning the root canal system and, compared with traditional syringe irrigation, it removes more organic tissue, planktonic bacteria and dentine debris from the root canal. PUI is more efficient in cleaning canals than ultrasonic irrigation with simultaneous ultrasonic instrumentation. PUI can be effective in curved canals and a smooth wire can be as effective as a cutting K-file.

The taper and the diameter of the root canal were found to be important parameters in determining the efficacies of dentine debris removal. Irrigation with sodium hypochlorite is more effective than with water and ultrasonic irrigation is more effective than sonic irrigation in the removal of dentine debris from the root canal. The role of cavitation during PUI remains inconclusive. No detailed information is available on the influence of the irrigation time, the volume of the irrigant, the penetration depth of the instrument and the shape and material properties of the instrument. The influence of irrigation frequency and intensity on the streaming pattern as well as the complicated interaction of acoustic streaming with the adherent biofilm needs to be clarified to reveal the underlying physical mechanisms of PUI. see more...

Corn Ethanol

Posted by Cindy Zimmerman – May 6th, 2009

Corn ethanol seems to have made out better than expected in the proposed rulemaking for the Renewable Fuels Standard (RFS) under the 2007 Energy Independence and Security Act (EISA) announced this week by the Obama administration, mainly because it allows the industry to provide more input regarding indirect land use impacts.

The National Corn Growers Association (NCGA) is pleased with President Obama’s commitment to the biofuels industry by the creation of the Biofuels Interagency Working Group and they hope that will help to inject more reason into the indirect land use debate.

“In our conversations with the Environmental Protection Agency, we understand that there is a great deal of work that needs to be done on modeling and a great effort that needs to be put into using current and correct data regarding indirect land use,” said NCGA President Bob Dickey. “NCGA will be working closely with the United States Department of Agriculture (USDA) and EPA to ensure scientific data is used.” see more....

Making Natural Gas Out of Algae

Posted by John Davis – May 6th, 2009
Scientists working for the federal government have found another way to turn algae into energy. The green pond scum has been found as a good source for biodiesel. Now, algae can be turned into natural gas.

This press release from the U.S. Department of Energy’s Pacific Northwest National Laboratory (PNNL) says the feds have transferred the technology to the marketplace under a license between Genifuel Corporation and Battelle:

The method, called catalytic hydrothermal gasification, creates natural gas out of algae - more quickly, more efficiently and at higher yields than other biofuel processes. Genifuel expects the process also requires less capital investment. The license agreement moves this technology for renewable energy production a step closer to commercial reality. Battelle operates PNNL for DOE. see more....