USFDA has issued a very important preliminary notification on possible malfunction of medical devices caused by CT scanning.The number of patients who carry medical devices in India is not known. Since such devices are very expensive the patients carrying them may be very few. According to sun-sentinel.com, in US,tens of millions of patients are outfitted with these technologies, which use electrical currents to help various organs overcome functional deficits.
K.S.Parthasarathy
FDA Preliminary1 Public Health Notification: Possible Malfunction of Electronic Medical Devices Caused by Computed Tomography (CT) Scanning
Date July 14, 2008
Dear Healthcare Professional:
This is to alert you to the possibility that the x-rays used during CT examinations may cause some implanted and external electronic medical devices to malfunction, and to provide recommendations to reduce the potential risk.
Most patients with electronic medical devices undergo CT scans without any adverse consequences. However, FDA has received a small number of reports of adverse events in which CT scans may have interfered with electronic medical devices, including pacemakers, defibrillators, neurostimulators, and implanted or externally worn drug infusion pumps. There have been similar reports in the literature.2-4
It is possible that this interference is being reported more frequently now because of the increased utilization of CT, the higher dose-rate capability of newer CT machines, an increase in the number of patients with implanted and externally worn electronic medical devices, and better reporting systems.
We are continuing to investigate this issue while working with device manufacturers and raising awareness in the healthcare community. To date, no patient deaths have been reported from CT scanning of implanted or externally worn electronic medical devices.
Adverse events
In the reports received by FDA, the following adverse events were likely to have been caused by x-rays from CT scans:
• Unintended “shocks” (i.e., stimuli) from neurostimulators
• Malfunctions of insulin infusion pumps
• Transient changes in pacemaker output pulse rate
Note that malfunctions of this kind, which can result from direct exposure of the medical device to the high x-ray dose rates generated by some CT equipment, are different from those related to MRI scanning, which are caused by strong electric and magnetic fields.
Recommendations
Before beginning a CT scan, the operator should use CT scout views to determine if implanted or externally worn electronic medical devices are present and if so, their location relative to the programmed scan range.
For CT procedures in which the medical device is in or immediately adjacent to the programmed scan range, the operator should:
• Determine the device type;
• If practical, try to move external devices out of the scan range;
• Ask patients with neurostimulators to shut off the device temporarily while the scan is performed;
• Minimize x-ray exposure to the implanted or externally worn electronic medical device by:
o Using the lowest possible x-ray tube current consistent with obtaining the required image quality; and
o Making sure that the x-ray beam does not dwell over the device for more than a few seconds;
Important note: For CT procedures that require scanning over the medical device continuously for more than a few seconds, as with CT perfusion or interventional exams, attending staff should be ready to take emergency measures to treat adverse reactions if they occur.
After CT scanning directly over the implanted or externally worn electronic medical device:
• Have the patient turn the device back on if it had been turned off prior to scanning.
• Have the patient check the device for proper functioning, even if the device was turned off.
• Advise patients to contact their healthcare provider as soon as possible if they suspect their device is not functioning properly after a CT scan.
Background
Experimental studies with anthropomorphic phantoms have demonstrated the potential for high dose rate CT irradiation to affect implanted cardiac rhythm management devices.3,4 Some occurrences in patients, which involved neurostimulator and pacemaker devices, have also been reported to FDA and appear in the literature.3,5
Electronic medical devices that theoretically could be affected by CT x-rays include, but are not limited to:
• cardiac pacemakers,
• implantable cardiac defibrillators,
• neurostimulators,
• drug infusion pumps, including insulin pumps,
• cochlear implants, and
• retinal implants.
While theoretically possible, reports of CT interference with cochlear implants and retinal implants have not been received to date.
Problems with electronic medical devices that might be caused by CT scanner interference include:
• generation of spurious signals, including cardiac defibrillation pulses
• misinterpretation of signals produced by the x-rays as actual biological signals
• missed detection of actual biological signals
• resetting or reprogramming of device settings
The type of effect, if any, is likely to depend on the device type, the manufacturer and the model.
Reporting to FDA
FDA requires hospitals and other user facilities to report deaths and serious injuries associated with the use of medical devices. If you suspect that a reportable adverse event was related to the use of CT equipment, you should follow the reporting procedure established by your facility.
We also encourage you to report adverse events that do not meet the requirements for mandatory reporting. You can report directly to MedWatch, the FDA Safety Information and Adverse Event Reporting program. You may submit reports online at www.fda.gov/MedWatch/report.htm, by phone 1-800-FDA-1088, or by returning the postage-paid FDA form 3500 which may be downloaded from www.fda.gov/MedWatch/getforms.htm by mail to MedWatch, 5600 Fishers Lane, Rockville, MD 20852-9787 or fax 1-800-FDA-0178.
Getting More Information
If you have questions about this Notification, please contact Issues Management Staff, Office of Surveillance and Biometrics (HFZ-510), 1350 Piccard Drive, Rockville, Maryland, 20850, by Fax at 240-276-3356, or by e-mail at phann@cdrh.fda.gov. You may also leave a voicemail message at 240-276-3357 and we will return your call as soon as possible.
FDA medical device Public Health Notifications are available on the Internet at http://www.fda.gov/cdrh/safety.html. You can also be notified through email on the day the safety notification is released by subscribing to our list server. To subscribe, visit: http://service.govdelivery.com/service/subscribe.html?code=USFDA_39.
Sincerely yours,
Daniel G. Schultz, MD
Director
Center for Devices and Radiological Health
Food and Drug Administration
1 CDRH Preliminary Public Health Notifications are intended to quickly share device-related safety information with healthcare providers when the available information and our understanding of an issue are still evolving. We will revise this Notification as new information merits and so encourage you to check this site for updates.
2 “Does High-Power Computed Tomography Scanning Equipment Affect the Operation of Pacemakers?,” Yamaji, S., et al., Circulation Journal 70:190-197 (2006).
3 “Effects of CT Irradiation on Implantable Cardiac Rhythm Management Devices,” McCollough, C., et al., Radiology 243 (3):766-774 (2007).
4 “Hazard Report—CT Scans Can Affect the Operation of Implanted Electronic Devices,” ECRI Institute Problem Reporting System, Health Devices 36 (4):136-138 (2007).
5 MedSun is the FDA's Medical Product Safety Network of 350 hospitals spread throughout the United States. Information from 132 of these facilities indicated that they have not experienced any CT medical device interference, while 3 have had from 1 to 3 events that may have been CT scan induced. Fifteen MedSun facilities indicated they take some precautionary steps when CT scanning patients who have electronic medical devices.
Updated July 14, 2008
Thursday, July 17, 2008
Tuesday, July 1, 2008
New electrostatic-based DNA microarray technique could revolutionize medical diagnostics
U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) has invented a technique in which DNA or RNA assays — the key to genetic profiling and disease detection — can be read and evaluated without the need of elaborate chemical labeling or sophisticated instrumentation. Based on electrostatic repulsion — in which objects with the same electrical charge repel one another — the technique is relatively simple and inexpensive to implement, and can be carried out in a matter of minutes.
The news release is prepared very carefully highlighting areas which are yet to be practically realized into the realm of reality!
K.S.Parthasarathy
Contact: Lynn Yarris
lcyarris@lbl.gov
510-486-5375
DOE/Lawrence Berkeley National Laboratory
New electrostatic-based DNA microarray technique could revolutionize medical diagnostics
DNA microarrays can be easily interrogated with only the naked eye using a new electrostatic imaging technique developed in the laboratory of Jay Groves, a chemist with Berkeley Lab,...
Click here for more information.
BERKELEY, CA — The dream of personalized medicine — in which diagnostics, risk predictions and treatment decisions are based on a patient's genetic profile — may be on the verge of being expanded beyond the wealthiest of nations with state-of-the-art clinics. A team of researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) has invented a technique in which DNA or RNA assays — the key to genetic profiling and disease detection — can be read and evaluated without the need of elaborate chemical labeling or sophisticated instrumentation. Based on electrostatic repulsion — in which objects with the same electrical charge repel one another — the technique is relatively simple and inexpensive to implement, and can be carried out in a matter of minutes.
"One of the most amazing things about our electrostatic detection method is that it requires nothing more than the naked eye to read out results that currently require chemical labeling and confocal laser scanners," said Jay Groves, a chemist with joint appointments at Berkeley Lab's Physical Biosciences Division and the Chemistry Department of the University of California (UC) at Berkeley, who led this research. "We believe this technique could revolutionize the use of DNA microarrays for both research and diagnostics."
A new method for reading DNA (or RNA) microarrays is based on measuring the electrostatic repulsion between silica microspheres and hybridized DNA. Surface areas containing double-stranded DNA (red) or single-stranded...
Click here for more information.
Groves, who is also a Howard Hughes Medical Institute (HHMI) investigator, and members of his research group Nathan Clack and Khalid Salaita, have published a paper on their technique in the journal Nature Biotechnology, which is now available online. The paper is entitled "Electrostatic readout of DNA microarrays with charged microspheres."
In their paper, Groves, Clack, and Salaita describe how dispersing a fluid containing thousands of electrically-charged microscopic beads or spheres made of silica (glass) across the surface of a DNA microarray and then observing the Brownian motion of the spheres provides measurements of the electrical charges of the DNA molecules. These measurements can in turn be used to interrogate millions of DNA sequences at a time. What's more, these measurements can be observed and recorded with a simple hand-held imaging device — even a cell phone camera will do.
"The assumption has been that no detection technique could be more sensitive than fluorescent labeling, but this is completely untrue, as our results have plainly demonstrated," said Groves. "We've shown that changes in surface charge density as a result of specific DNA hybridization can be detected and quantified with 50-picometer sensitivity, single base-pair mismatch selectivity, and in the presence of complex backgrounds. Furthermore, our electrostatic detection technique should render DNA and RNA microarrays sufficiently cost effective for broad world-health applications, as well as research."
Your susceptibility to a given disease and how your body will respond to drugs or other interventions is unique to your genetic makeup. Under a personalized medicine plan, treatment effectiveness is maximized and risks are minimized by tailoring disease treatments specifically to you. This requires the precise diagnostic tests and targeted therapies that can stem from assays using a DNA microarray — a thumbnail-sized substrate containing thousands of microscopic spots of oligonucleotides (stretches of DNA about 20 base pairs in length) laid out in a grid.
Often referred to as "gene chips," DNA microarray assays and their RNA counterparts have become one of the most powerful tools for gene-expression profiling, the identification of mutations, and the detection of multiple pathogens in patients afflicted either by multiple diseases or drug-resistant strains of diseases. Aside from their potential future role in personalized medicine, the widespread use of DNA microarray assay devices could have an immediate and profound impact on the treatment of diseases today. For example, according to a report two years ago from the Global Health Diagnostics Forum, 400,000 lives could be saved each year from death by tuberculosis through the use of DNA microarray assays rather than the standard TB diagnostic test, which is known to miss nearly half of all cases.
Until now, however, the use of DNA microarray assays has been limited because current techniques typically depend upon fluorescence detection, a demanding methodology that requires time-consuming chemical labeling, high-power excitation sources, and sophisticated instrumentation for scanning. Such demands are generally well beyond the capabilities of individual laboratories or clinics, especially in developing countries. While label-free DNA detection strategies do exist, they require either complex device fabrication or sophisticated instrumentation for readouts, and in addition none are compatible with conventional DNA microarrays, where up to one million sequences are available for interrogation in a single experiment.
"We have demonstrated parallel sampling of a microarray surface with micron-scale resolutions over centimeter-scale lengths," said Groves. "This is four orders of magnitude larger than what has been achieved to date with conventional scanning-electrostatic-force microscopy."
In a typical experiment, a microarray is prepared and mounted in a well chamber and the DNA is hybridized (a standard technique in which complementary single strands of DNA bind to form double-stranded DNA "hybrids"). A suspension of negatively-charged silica microspheres is then dispersed through gravitational sedimentation over the microarray surface, a process which takes about 20 minutes. Because the substrate or background surface of the microassay is positively charged, the silica microspheres will spread across the entire surface and adhere to it. However, on surface areas containing double-stranded DNA, which is highly negatively charged, and on areas containing single-stranded DNA, also negatively charged but to a lesser degree than double-stranded DNA, the microspheres will levitate above the substrate surface, stacking up in "equilibrium heights" that are dictated by a balance between gravitational and electrostatic forces.
These electrostatic interactions on the microarray surface result in charge-density contrasts that are readily observed. Surface areas containing DNA segments take on a frosted or translucent appearance, and can be correlated to specific hybridizations that reveal the presence of genes, mutations and pathogens.
"Our technique is essentially a millionfold parallel version of the classic experiment used by Robert Millikan almost 100 years ago, when he determined the charge of a single electron by observing the positions of oil droplets levitated above a charged plate," said Groves.
There are a number of short-term "next steps" for this research, Groves said, including testing its application in high-density arrays and pushing its ultimate resolution limits.
"Since the resolution of electrostatic-based imaging is determined by the number of particle-observations rather than by the diffraction limit of light, our readouts could serve as a form of ultramicroscopy," he said. "The real grand challenge for this technology, however, will be for us to find suitable industrial partners with whom we can work to see that useful new products actually make it to market."
###
The electrostatic detection technology is now available for licensing through Berkeley Lab's Technology Transfer Department; visit their website at http://www.lbl.gov/Tech-Transfer/index.html.
This research was funded by the U.S. Department of Energy's Office of Science through its Office of Basic Energy Sciences.
Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research and is managed by the University of California. Visit our website at www.lbl.gov.
The news release is prepared very carefully highlighting areas which are yet to be practically realized into the realm of reality!
K.S.Parthasarathy
Contact: Lynn Yarris
lcyarris@lbl.gov
510-486-5375
DOE/Lawrence Berkeley National Laboratory
New electrostatic-based DNA microarray technique could revolutionize medical diagnostics
DNA microarrays can be easily interrogated with only the naked eye using a new electrostatic imaging technique developed in the laboratory of Jay Groves, a chemist with Berkeley Lab,...
Click here for more information.
BERKELEY, CA — The dream of personalized medicine — in which diagnostics, risk predictions and treatment decisions are based on a patient's genetic profile — may be on the verge of being expanded beyond the wealthiest of nations with state-of-the-art clinics. A team of researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) has invented a technique in which DNA or RNA assays — the key to genetic profiling and disease detection — can be read and evaluated without the need of elaborate chemical labeling or sophisticated instrumentation. Based on electrostatic repulsion — in which objects with the same electrical charge repel one another — the technique is relatively simple and inexpensive to implement, and can be carried out in a matter of minutes.
"One of the most amazing things about our electrostatic detection method is that it requires nothing more than the naked eye to read out results that currently require chemical labeling and confocal laser scanners," said Jay Groves, a chemist with joint appointments at Berkeley Lab's Physical Biosciences Division and the Chemistry Department of the University of California (UC) at Berkeley, who led this research. "We believe this technique could revolutionize the use of DNA microarrays for both research and diagnostics."
A new method for reading DNA (or RNA) microarrays is based on measuring the electrostatic repulsion between silica microspheres and hybridized DNA. Surface areas containing double-stranded DNA (red) or single-stranded...
Click here for more information.
Groves, who is also a Howard Hughes Medical Institute (HHMI) investigator, and members of his research group Nathan Clack and Khalid Salaita, have published a paper on their technique in the journal Nature Biotechnology, which is now available online. The paper is entitled "Electrostatic readout of DNA microarrays with charged microspheres."
In their paper, Groves, Clack, and Salaita describe how dispersing a fluid containing thousands of electrically-charged microscopic beads or spheres made of silica (glass) across the surface of a DNA microarray and then observing the Brownian motion of the spheres provides measurements of the electrical charges of the DNA molecules. These measurements can in turn be used to interrogate millions of DNA sequences at a time. What's more, these measurements can be observed and recorded with a simple hand-held imaging device — even a cell phone camera will do.
"The assumption has been that no detection technique could be more sensitive than fluorescent labeling, but this is completely untrue, as our results have plainly demonstrated," said Groves. "We've shown that changes in surface charge density as a result of specific DNA hybridization can be detected and quantified with 50-picometer sensitivity, single base-pair mismatch selectivity, and in the presence of complex backgrounds. Furthermore, our electrostatic detection technique should render DNA and RNA microarrays sufficiently cost effective for broad world-health applications, as well as research."
Your susceptibility to a given disease and how your body will respond to drugs or other interventions is unique to your genetic makeup. Under a personalized medicine plan, treatment effectiveness is maximized and risks are minimized by tailoring disease treatments specifically to you. This requires the precise diagnostic tests and targeted therapies that can stem from assays using a DNA microarray — a thumbnail-sized substrate containing thousands of microscopic spots of oligonucleotides (stretches of DNA about 20 base pairs in length) laid out in a grid.
Often referred to as "gene chips," DNA microarray assays and their RNA counterparts have become one of the most powerful tools for gene-expression profiling, the identification of mutations, and the detection of multiple pathogens in patients afflicted either by multiple diseases or drug-resistant strains of diseases. Aside from their potential future role in personalized medicine, the widespread use of DNA microarray assay devices could have an immediate and profound impact on the treatment of diseases today. For example, according to a report two years ago from the Global Health Diagnostics Forum, 400,000 lives could be saved each year from death by tuberculosis through the use of DNA microarray assays rather than the standard TB diagnostic test, which is known to miss nearly half of all cases.
Until now, however, the use of DNA microarray assays has been limited because current techniques typically depend upon fluorescence detection, a demanding methodology that requires time-consuming chemical labeling, high-power excitation sources, and sophisticated instrumentation for scanning. Such demands are generally well beyond the capabilities of individual laboratories or clinics, especially in developing countries. While label-free DNA detection strategies do exist, they require either complex device fabrication or sophisticated instrumentation for readouts, and in addition none are compatible with conventional DNA microarrays, where up to one million sequences are available for interrogation in a single experiment.
"We have demonstrated parallel sampling of a microarray surface with micron-scale resolutions over centimeter-scale lengths," said Groves. "This is four orders of magnitude larger than what has been achieved to date with conventional scanning-electrostatic-force microscopy."
In a typical experiment, a microarray is prepared and mounted in a well chamber and the DNA is hybridized (a standard technique in which complementary single strands of DNA bind to form double-stranded DNA "hybrids"). A suspension of negatively-charged silica microspheres is then dispersed through gravitational sedimentation over the microarray surface, a process which takes about 20 minutes. Because the substrate or background surface of the microassay is positively charged, the silica microspheres will spread across the entire surface and adhere to it. However, on surface areas containing double-stranded DNA, which is highly negatively charged, and on areas containing single-stranded DNA, also negatively charged but to a lesser degree than double-stranded DNA, the microspheres will levitate above the substrate surface, stacking up in "equilibrium heights" that are dictated by a balance between gravitational and electrostatic forces.
These electrostatic interactions on the microarray surface result in charge-density contrasts that are readily observed. Surface areas containing DNA segments take on a frosted or translucent appearance, and can be correlated to specific hybridizations that reveal the presence of genes, mutations and pathogens.
"Our technique is essentially a millionfold parallel version of the classic experiment used by Robert Millikan almost 100 years ago, when he determined the charge of a single electron by observing the positions of oil droplets levitated above a charged plate," said Groves.
There are a number of short-term "next steps" for this research, Groves said, including testing its application in high-density arrays and pushing its ultimate resolution limits.
"Since the resolution of electrostatic-based imaging is determined by the number of particle-observations rather than by the diffraction limit of light, our readouts could serve as a form of ultramicroscopy," he said. "The real grand challenge for this technology, however, will be for us to find suitable industrial partners with whom we can work to see that useful new products actually make it to market."
###
The electrostatic detection technology is now available for licensing through Berkeley Lab's Technology Transfer Department; visit their website at http://www.lbl.gov/Tech-Transfer/index.html.
This research was funded by the U.S. Department of Energy's Office of Science through its Office of Basic Energy Sciences.
Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research and is managed by the University of California. Visit our website at www.lbl.gov.
Friday, June 13, 2008
crude 'oil' from pig manure
Chemists at the US National Institute of Standards and Technology (NIST)have developed a method to make crude oil from pig manure!Not surprising any more as the price of petrol is currently $4 gallon in USA. Pigsty owners will be delighted to supply the "raw material" without any hindrance!The trouble is that "Whatever the pigs eat, from dirt to nutritional supplements, ends up in the oil". Scientists concede.
NIST researchers found that pig manure crude contains at least "83 major compounds, including many components that would need to be removed, such as about 15 percent water by volume, sulfur that otherwise could end up as pollution in vehicle exhaust, and lots of char waste containing heavy metals, including iron, zinc, silver, cobalt, chromium, lanthanum, scandium, tungsten and minute amounts of gold and hafnium".
May be the farmers must subsidize the process to make usable crude from pig manure!
K.S.Parthasarathy
Public release date: 12-Jun-2008
Contact: Laura Ost
laura.ost@nist.gov
303-497-4880
National Institute of Standards and Technology (NIST)
NIST chemists get scoop on crude 'oil' from pig manure
To watch NIST chemist Tom Bruno talk about his research on crude oil made from pig manure, go to http://www.nist.gov/public_affairs/techbeat/tb2008_0610.htm#crude
Click here for more information.
After a close examination of crude oil made from pig manure, chemists at the National Institute of Standards and Technology (NIST) are certain about a number of things.
Most obviously, "This stuff smells worse than manure," says NIST chemist Tom Bruno.
But a job's a job, so the NIST team has developed the first detailed chemical analysis revealing what processing is needed to transform pig manure crude oil into fuel for vehicles or heating. Mass production of this type of biofuel could help consume a waste product overflowing at U.S. farms, and possibly enable cutbacks in the nation's petroleum use and imports. But, according to a new NIST paper,* pig manure crude will require a lot of refining.
The ersatz oil used in the NIST analyses was provided by engineer Yuanhui Zhang of the University of Illinois Urbana-Champaign. Zhang developed a system using heat and pressure to transform organic compounds such as manure into oil.
As described in the new paper, Bruno and colleagues determined that the pig manure crude contains at least 83 major compounds, including many components that would need to be removed, such as about 15 percent water by volume, sulfur that otherwise could end up as pollution in vehicle exhaust, and lots of char waste containing heavy metals, including iron, zinc, silver, cobalt, chromium, lanthanum, scandium, tungsten and minute amounts of gold and hafnium. Whatever the pigs eat, from dirt to nutritional supplements, ends up in the oil.
While the thick black liquid may look like its petroleum-based counterparts, the NIST study shows that looks can be deceiving. "The fact that pig manure crude oil contains a lot of water is unfavorable. They would need to get the water out," Bruno says.
The measurements were made with a new NIST test method and apparatus, the advanced distillation curve, which provides highly detailed and accurate data on the makeup and performance of complex fluids. A distillation curve charts the percentage of the total mixture that evaporates as a sample is slowly heated. Because the different components of a complex mixture typically have different boiling points, a distillation curve gives a good measure of the relative amount of each component in the mixture. NIST chemists enhanced the traditional technique by improving precision and control of temperature measurements and adding the capability to analyze the chemical composition of each boiling fraction using a variety of advanced methods.
NIST researchers analyzed the graphite-like char remaining after the distillation by bombarding it with neutrons, a non-destructive way of identifying the types and amounts of elements present. Two complementary neutron methods detected the heavy metals listed above.
Bruno and colleagues currently spend much of their time analyzing military jet fuels and are not planning a major foray into pig manure. But Bruno concedes that the effort may have a payoff. "Who knows, it might help decrease the nuisance of manure piles."
###
For more on the process of making pig waste crude, see "Converting Manure to Oil: U of I Lays Groundwork for One-of-a-Kind Pilot Plant". http://www.aces.uiuc.edu/news/stories/news3557.html
To view a video clip of Tom Bruno describing the work, please go to: http://www.nist.gov/public_affairs/techbeat/tb2008_0610.htm#crude
* L.S. Ott, B.L. Smith and T.J. Bruno. Advanced distillation curve measurement: Application to a bio-derived crude oil prepared from swine manure. Fuel (2008), doi:10.1016/j.fuel.2008.04.038.
NIST researchers found that pig manure crude contains at least "83 major compounds, including many components that would need to be removed, such as about 15 percent water by volume, sulfur that otherwise could end up as pollution in vehicle exhaust, and lots of char waste containing heavy metals, including iron, zinc, silver, cobalt, chromium, lanthanum, scandium, tungsten and minute amounts of gold and hafnium".
May be the farmers must subsidize the process to make usable crude from pig manure!
K.S.Parthasarathy
Public release date: 12-Jun-2008
Contact: Laura Ost
laura.ost@nist.gov
303-497-4880
National Institute of Standards and Technology (NIST)
NIST chemists get scoop on crude 'oil' from pig manure
To watch NIST chemist Tom Bruno talk about his research on crude oil made from pig manure, go to http://www.nist.gov/public_affairs/techbeat/tb2008_0610.htm#crude
Click here for more information.
After a close examination of crude oil made from pig manure, chemists at the National Institute of Standards and Technology (NIST) are certain about a number of things.
Most obviously, "This stuff smells worse than manure," says NIST chemist Tom Bruno.
But a job's a job, so the NIST team has developed the first detailed chemical analysis revealing what processing is needed to transform pig manure crude oil into fuel for vehicles or heating. Mass production of this type of biofuel could help consume a waste product overflowing at U.S. farms, and possibly enable cutbacks in the nation's petroleum use and imports. But, according to a new NIST paper,* pig manure crude will require a lot of refining.
The ersatz oil used in the NIST analyses was provided by engineer Yuanhui Zhang of the University of Illinois Urbana-Champaign. Zhang developed a system using heat and pressure to transform organic compounds such as manure into oil.
As described in the new paper, Bruno and colleagues determined that the pig manure crude contains at least 83 major compounds, including many components that would need to be removed, such as about 15 percent water by volume, sulfur that otherwise could end up as pollution in vehicle exhaust, and lots of char waste containing heavy metals, including iron, zinc, silver, cobalt, chromium, lanthanum, scandium, tungsten and minute amounts of gold and hafnium. Whatever the pigs eat, from dirt to nutritional supplements, ends up in the oil.
While the thick black liquid may look like its petroleum-based counterparts, the NIST study shows that looks can be deceiving. "The fact that pig manure crude oil contains a lot of water is unfavorable. They would need to get the water out," Bruno says.
The measurements were made with a new NIST test method and apparatus, the advanced distillation curve, which provides highly detailed and accurate data on the makeup and performance of complex fluids. A distillation curve charts the percentage of the total mixture that evaporates as a sample is slowly heated. Because the different components of a complex mixture typically have different boiling points, a distillation curve gives a good measure of the relative amount of each component in the mixture. NIST chemists enhanced the traditional technique by improving precision and control of temperature measurements and adding the capability to analyze the chemical composition of each boiling fraction using a variety of advanced methods.
NIST researchers analyzed the graphite-like char remaining after the distillation by bombarding it with neutrons, a non-destructive way of identifying the types and amounts of elements present. Two complementary neutron methods detected the heavy metals listed above.
Bruno and colleagues currently spend much of their time analyzing military jet fuels and are not planning a major foray into pig manure. But Bruno concedes that the effort may have a payoff. "Who knows, it might help decrease the nuisance of manure piles."
###
For more on the process of making pig waste crude, see "Converting Manure to Oil: U of I Lays Groundwork for One-of-a-Kind Pilot Plant". http://www.aces.uiuc.edu/news/stories/news3557.html
To view a video clip of Tom Bruno describing the work, please go to: http://www.nist.gov/public_affairs/techbeat/tb2008_0610.htm#crude
* L.S. Ott, B.L. Smith and T.J. Bruno. Advanced distillation curve measurement: Application to a bio-derived crude oil prepared from swine manure. Fuel (2008), doi:10.1016/j.fuel.2008.04.038.
Thursday, June 12, 2008
Nuclear power generation slipped 1.9% last year, though there is news that the technology is poised for growth in many countries
K.S. Parthasarathy
Nuclear Policies
Nuclear generation drops 1.9% in 2007
09 June 2008
Figures from the International Atomic Energy Agency (IAEA) show that nuclear power generation worldwide was 50 TWh lower in 2007 than in 2006, mainly due to cutbacks in three countries.
Kashiwazaki Kariwa
Kashiwazaki Kariwa is the biggest
nuclear power plant in the world.
Its extended outage has dented global
generation figures (Image: Tepco)
This 1.9% drop, from 2658 to 2608 TWh, was the first significant decline in world nuclear output in four years.
In Japan, the closure of 8000 MWe of capacity at Tokyo Electric Power Company's (Tepco's) Kashiwazaki Kariwa plant in Niigata prefecture following the earthquake on 16 July had a marked influence. The plant's closure led to Japan's nuclear electricity production dropping by almost 25 TWh to 267.3 TWh in 2007, despite no damage having been found to the reactors.
In the UK, the four oldest reactors - at Dungeness A and Sizewell A - were retired at the end of 2006 and then two larger ones - Hartlepool 2 and Heysham 1 - were laid up with boiler (steam generator) problems, leading to a drop in output of almost 12 TWh.
In Germany, there was a drop of 25 TWh due to the Brunsbuttel and Krummel nuclear power plants being shut down in June due to short circuits in the electricity grid, removing about 2000 MWe of capacity. In addition, the Biblis A and B nuclear plants, totalling 2400 MWe, remained offline due to regulatory issues for part of the year.
However, several countries reported increases in nuclear generation: Bulgaria (up 32% to 13.7 TWh); China (up 14.5% to 59.3 TWh); Russia (up 2.5% to 148.0 TWh); South Africa (up 24.7% to 12.6 TWh); and the USA (up 2.5% to 806.6 TWh) - the last amounting to 19.4 TWh.
France remained the country most reliant on nuclear energy for its electricity, producing some 420 TWh, accounting for almost 77% of its total electricity output. Lithuania followed, with 9 TWh of nuclear electricity accounting for almost 65% of its total electricity output.
According to the IAEA's Power Reactor Information System (PRIS) database, three new nuclear power reactors were connected to the grid in 2007: Kaiga 3 in India, Tianwan 2 in China and Cernavoda 2 in Romania. In addition, the Browns Ferry 1 reactor in the USA returned to service after a long-term shut down.
Also in 2007, construction of five reactors commenced: Qinshan II-4 and Hongyanhe 1 in China; Shin Kori 2 and Shin Wolsong 1 in South Korea; and the Flamanville 3 unit in France. Construction of two floating reactors was also begun in Russia. In addition, construction was also resumed in 2007 of the USA's Watts Bar 2 unit.
K.S. Parthasarathy
Nuclear Policies
Nuclear generation drops 1.9% in 2007
09 June 2008
Figures from the International Atomic Energy Agency (IAEA) show that nuclear power generation worldwide was 50 TWh lower in 2007 than in 2006, mainly due to cutbacks in three countries.
Kashiwazaki Kariwa
Kashiwazaki Kariwa is the biggest
nuclear power plant in the world.
Its extended outage has dented global
generation figures (Image: Tepco)
This 1.9% drop, from 2658 to 2608 TWh, was the first significant decline in world nuclear output in four years.
In Japan, the closure of 8000 MWe of capacity at Tokyo Electric Power Company's (Tepco's) Kashiwazaki Kariwa plant in Niigata prefecture following the earthquake on 16 July had a marked influence. The plant's closure led to Japan's nuclear electricity production dropping by almost 25 TWh to 267.3 TWh in 2007, despite no damage having been found to the reactors.
In the UK, the four oldest reactors - at Dungeness A and Sizewell A - were retired at the end of 2006 and then two larger ones - Hartlepool 2 and Heysham 1 - were laid up with boiler (steam generator) problems, leading to a drop in output of almost 12 TWh.
In Germany, there was a drop of 25 TWh due to the Brunsbuttel and Krummel nuclear power plants being shut down in June due to short circuits in the electricity grid, removing about 2000 MWe of capacity. In addition, the Biblis A and B nuclear plants, totalling 2400 MWe, remained offline due to regulatory issues for part of the year.
However, several countries reported increases in nuclear generation: Bulgaria (up 32% to 13.7 TWh); China (up 14.5% to 59.3 TWh); Russia (up 2.5% to 148.0 TWh); South Africa (up 24.7% to 12.6 TWh); and the USA (up 2.5% to 806.6 TWh) - the last amounting to 19.4 TWh.
France remained the country most reliant on nuclear energy for its electricity, producing some 420 TWh, accounting for almost 77% of its total electricity output. Lithuania followed, with 9 TWh of nuclear electricity accounting for almost 65% of its total electricity output.
According to the IAEA's Power Reactor Information System (PRIS) database, three new nuclear power reactors were connected to the grid in 2007: Kaiga 3 in India, Tianwan 2 in China and Cernavoda 2 in Romania. In addition, the Browns Ferry 1 reactor in the USA returned to service after a long-term shut down.
Also in 2007, construction of five reactors commenced: Qinshan II-4 and Hongyanhe 1 in China; Shin Kori 2 and Shin Wolsong 1 in South Korea; and the Flamanville 3 unit in France. Construction of two floating reactors was also begun in Russia. In addition, construction was also resumed in 2007 of the USA's Watts Bar 2 unit.
Theft in Trombay, Chernobyl
A week ago thieves stole a swathe of telephone cables connecting Anushaktinagar, (the residential complex in which most of the scientists working in various units of the Department of Atomic Energy live) with the outside world. The Banks at the premises and schools and a few other institutions did not have phone service for a week
Almost two weeks earlier the following news appeared in the Russian paper RIA Novosti 30 May
Chernobyl chopper café plan thwarted
A gang has been arrested in Ukraine for planning to smuggle contaminated wood and scrap metal, including a helicopter, from the 18-mile exclusion zone surrounding the damaged Chernobyl nuclear power plant. In a statement, the country's security service reported that it had "identified and put a stop to the unlawful activities of a criminal gang, which had been illegally removing from Chernobyl radioactive scrap metal, automobile spare parts and timber." The statement said that the timber was usually reprocessed at covert plants and later sold as construction materials, while the metal items were usually melted down for scrap. However, the security service said the gang had also "tried to take an Mi-8 helicopter out of the exclusion zone to use it as an original coffee shop in one of Ukraine's cities." The Mi-8 helicopter was the workhorse of the Soviet armed forces and is capable of carrying up to 28 people. It was not made clear how many customers the gang had been hoping to seat.
Interesting nuclear news!!
Almost two weeks earlier the following news appeared in the Russian paper RIA Novosti 30 May
Chernobyl chopper café plan thwarted
A gang has been arrested in Ukraine for planning to smuggle contaminated wood and scrap metal, including a helicopter, from the 18-mile exclusion zone surrounding the damaged Chernobyl nuclear power plant. In a statement, the country's security service reported that it had "identified and put a stop to the unlawful activities of a criminal gang, which had been illegally removing from Chernobyl radioactive scrap metal, automobile spare parts and timber." The statement said that the timber was usually reprocessed at covert plants and later sold as construction materials, while the metal items were usually melted down for scrap. However, the security service said the gang had also "tried to take an Mi-8 helicopter out of the exclusion zone to use it as an original coffee shop in one of Ukraine's cities." The Mi-8 helicopter was the workhorse of the Soviet armed forces and is capable of carrying up to 28 people. It was not made clear how many customers the gang had been hoping to seat.
Interesting nuclear news!!
Friday, February 22, 2008
Modified electron microscope identifies atoms
A new electron microscope recently installed in Cornell's Duffield Hall enables scientists for the first time to form images that uniquely identify individual atoms in a crystal and see how those atoms bond to one another. And in living color.
K.S.Parthasarathy
Public release date: 21-Feb-2008
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Contact: Blaine Friedlander
bpf2@cornell.edu
607-254-8093
Cornell University Communications
Modified electron microscope identifies atoms
A new electron microscope recently installed in Cornell's Duffield Hall is enabling scientists for the first time to form images that uniquely identify individual atoms in a crystal and see how those atoms bond to one another. And in living color.
"The current generation of electron microscopes can be thought of as expensive black and white cameras where different atoms appear as different shades of gray," explained David Muller, Cornell associate professor of applied and engineering physics. "This microscope takes color pictures -- where each colored atom represents a uniquely identified chemical species."
The instrument is a new type of scanning transmission electron microscope (STEM), built by the NION Company of Kirkland, Wash., under an instrument-development award to Cornell from the National Science Foundation (NSF). John Silcox, the David E. Burr Professor of Engineering at Cornell, and Ondrej Krivanek of NION are co-principal investigators on the project.
The microscope incorporates new aberration-correction technology designed by Krivanek that focuses a beam of electrons on a spot smaller than a single atom -- more sharply and with greater intensity than previously possible. This allows information previously hidden in the background, or "noise," to be seen. It also provides up to a hundredfold increase in imaging speed.
The capabilities of the new instrument in analyzing a test sample are described in an article in the Feb. 22 issue of the journal Science by Muller, Silcox, Krivanek and colleagues at Cornell and in Korea and Japan.
It allows scientists to peer inside a material or a device and see how it is put together at the atomic scale where quantum effects dominate and everyday intuition fails. One of the most important applications of the new instrument will be to conduct what Silcox calls "materials pathology" to aid researchers in their development of new materials to use in electronic circuits, computer memories and other nanoscale devices. "We can look at structures people have built and tell them if they've built what they thought they did," Silcox explained.
A STEM shoots an electron beam through a thin-film sample and scans the beam across the sample in subatomic steps. In addition to forming an image, the new microscope can identify atoms in its path by a process called electron energy-loss spectrometry. Atoms in the path of the beam absorb energy from some of its electrons to kick their own electrons into higher orbits. The amount of energy this takes is different for each kind of atom.
The detector that collects electrons emerging from the sample measures the energy losses, and from this the atoms in the path of the beam can be identified. The detector can simultaneously produce multiple images -- one for every different species of atom in the sample, and these can be color-coded, each color representing a different electron energy signature.
The method also can show how atoms are bonded to one another in a crystal, because the bonding creates small shifts in the energy signatures. In earlier STEMS, many electrons from the beam, including those with changed energies, were scattered at wide angles by simple collisions with atoms. The new STEM includes magnetic lenses that collect emerging electrons over a wider angle. Previously, Silcox said, about 8 percent of the emerging electrons were collected, but the new detector collects about 80 percent, allowing more accurate readings of the small changes in energy levels that reveal bonding between atoms.
More complete collection and a brighter and a more sharply focused beam also allow the new microscope to scan much faster. In early tests it collected a 4,096-pixel image in about 30 seconds, 50 to 100 times faster than in conventional STEMs.
To demonstrate the capability of the new instrument, Muller examined a sample consisting of layers of two different materials: lanthanum-strontium-manganese oxide and strontium-titanate. This was done as part of a research project on which he is collaborating with scientists in Korea and Japan. "It's an artificial structure that will have interesting magnetic and electrical properties," he said, "but for it to work properly we have to make atomically sharp interfaces between the layers. It's really important to know if a few atoms leaked across the interface."
In the color image from the new STEM, where manganese appears red and titanium blue, a line of purple shows mixing at the edge between the two layers. "We've learned that there's room for improvement," Muller says, adding "This wasn't our best sample, but if we had put that one in it would have been a fairly boring image."
The new instrument arrived at Cornell in October, and is still undergoing calibration and testing.
The problems that limited electron imaging were identified as long ago as 1935, Silcox said, and ideas for overcoming them were outlined in 1947. But it was not until very recently that the engineering obstacles to putting them into practice were overcome. Largely, he said, this is because the problem required advanced computing, including computers to design the instrument, computer-controlled machinery to manufacture parts to fine tolerances, and computers to control the instrument itself.
###
K.S.Parthasarathy
Public release date: 21-Feb-2008
[ Print Article | E-mail Article | Close Window ]
Contact: Blaine Friedlander
bpf2@cornell.edu
607-254-8093
Cornell University Communications
Modified electron microscope identifies atoms
A new electron microscope recently installed in Cornell's Duffield Hall is enabling scientists for the first time to form images that uniquely identify individual atoms in a crystal and see how those atoms bond to one another. And in living color.
"The current generation of electron microscopes can be thought of as expensive black and white cameras where different atoms appear as different shades of gray," explained David Muller, Cornell associate professor of applied and engineering physics. "This microscope takes color pictures -- where each colored atom represents a uniquely identified chemical species."
The instrument is a new type of scanning transmission electron microscope (STEM), built by the NION Company of Kirkland, Wash., under an instrument-development award to Cornell from the National Science Foundation (NSF). John Silcox, the David E. Burr Professor of Engineering at Cornell, and Ondrej Krivanek of NION are co-principal investigators on the project.
The microscope incorporates new aberration-correction technology designed by Krivanek that focuses a beam of electrons on a spot smaller than a single atom -- more sharply and with greater intensity than previously possible. This allows information previously hidden in the background, or "noise," to be seen. It also provides up to a hundredfold increase in imaging speed.
The capabilities of the new instrument in analyzing a test sample are described in an article in the Feb. 22 issue of the journal Science by Muller, Silcox, Krivanek and colleagues at Cornell and in Korea and Japan.
It allows scientists to peer inside a material or a device and see how it is put together at the atomic scale where quantum effects dominate and everyday intuition fails. One of the most important applications of the new instrument will be to conduct what Silcox calls "materials pathology" to aid researchers in their development of new materials to use in electronic circuits, computer memories and other nanoscale devices. "We can look at structures people have built and tell them if they've built what they thought they did," Silcox explained.
A STEM shoots an electron beam through a thin-film sample and scans the beam across the sample in subatomic steps. In addition to forming an image, the new microscope can identify atoms in its path by a process called electron energy-loss spectrometry. Atoms in the path of the beam absorb energy from some of its electrons to kick their own electrons into higher orbits. The amount of energy this takes is different for each kind of atom.
The detector that collects electrons emerging from the sample measures the energy losses, and from this the atoms in the path of the beam can be identified. The detector can simultaneously produce multiple images -- one for every different species of atom in the sample, and these can be color-coded, each color representing a different electron energy signature.
The method also can show how atoms are bonded to one another in a crystal, because the bonding creates small shifts in the energy signatures. In earlier STEMS, many electrons from the beam, including those with changed energies, were scattered at wide angles by simple collisions with atoms. The new STEM includes magnetic lenses that collect emerging electrons over a wider angle. Previously, Silcox said, about 8 percent of the emerging electrons were collected, but the new detector collects about 80 percent, allowing more accurate readings of the small changes in energy levels that reveal bonding between atoms.
More complete collection and a brighter and a more sharply focused beam also allow the new microscope to scan much faster. In early tests it collected a 4,096-pixel image in about 30 seconds, 50 to 100 times faster than in conventional STEMs.
To demonstrate the capability of the new instrument, Muller examined a sample consisting of layers of two different materials: lanthanum-strontium-manganese oxide and strontium-titanate. This was done as part of a research project on which he is collaborating with scientists in Korea and Japan. "It's an artificial structure that will have interesting magnetic and electrical properties," he said, "but for it to work properly we have to make atomically sharp interfaces between the layers. It's really important to know if a few atoms leaked across the interface."
In the color image from the new STEM, where manganese appears red and titanium blue, a line of purple shows mixing at the edge between the two layers. "We've learned that there's room for improvement," Muller says, adding "This wasn't our best sample, but if we had put that one in it would have been a fairly boring image."
The new instrument arrived at Cornell in October, and is still undergoing calibration and testing.
The problems that limited electron imaging were identified as long ago as 1935, Silcox said, and ideas for overcoming them were outlined in 1947. But it was not until very recently that the engineering obstacles to putting them into practice were overcome. Largely, he said, this is because the problem required advanced computing, including computers to design the instrument, computer-controlled machinery to manufacture parts to fine tolerances, and computers to control the instrument itself.
###
Friday, February 15, 2008
Remarkable new clothing may someday power your iPod
It is appropriate that technologists are trying to make "small" power generators for use with cell phones and IPODS. Once perfected they will have a huge market. The report published in the February issue of Nature explains an effort in that direction.
K.S.Parthasarathy
Public release date: 13-Feb-2008
[ Print Article | E-mail Article | Close Window ]
Contact: Diane Banegas
dbanegas@nsf.gov
703-292-4489
National Science Foundation
Remarkable new clothing may someday power your iPod
The promise of piezoelectric fiber pairs
A schematic illustration of a "bottle-brush " structure shows nanowires arranged around a fiber. The relative "scrubbing " of the two brushes generates electricity.
Click here for more information.
Nanotechnology researchers at the Georgia Institute of Technology are developing a shirt that harvests energy from the wearer's physical motion and converts it into electricity for powering small electronic devices worn by soldiers in the field, hikers and other users.
The research, funded by the National Science Foundation (NSF) and described in the Feb. 14 issue of Nature, details how pairs of textile fibers covered with zinc oxide nanowires generate electricity in response to applied mechanical stress. Known as "the piezoelectric effect," the resulting current flow from many fiber pairs woven into a shirt or jacket could allow the wearer's body movement to power a range of portable electronic devices. The fibers could also be woven into curtains, tents or other structures to capture energy from wind motion, sound vibration or other mechanical energy.
The Georgia Tech research team for fiber nanogenerators: (left to right) Zhong Lin Wang, Xudong Wang and Yong Qin.
Click here for more information.
"The two fibers scrub together just like two bottle brushes with their bristles touching, and the piezoelectric-semiconductor process converts the mechanical motion into electrical energy," Zhong Lin Wang, a Regents professor in the School of Materials Science and Engineering at the Georgia Institute of Technology. "Many of these devices could be put together to produce higher power output."
Wang and collaborators Xudong Wang and Yong Qin have made more than 200 of the fiber nanogenerators. Each is tested on an apparatus that uses a spring and wheel to move one fiber against the other. The fibers are rubbed together for up to 30 minutes to test their durability and power production.
The researchers have measured current of about four nanoamperes and output voltage of about four millivolts from a nanogenerator that included two fibers that were each one centimeter long. With a much improved design, Wang estimates that a square meter of fabric made from the special fibers could theoretically generate as much as 80 milliwatts of power.
So far, there is only one wrinkle in the fabric, so to speak - washing it. Zinc oxide is sensitive to moisture, so in real shirts or jackets, the nanowires would have to be protected from the effects of the washing machine.
###
The research was funded by NSF's Division of Materials Research through grant #0706436. "This multi-disciplinary research grant enables materials scientists and engineers from varied backgrounds to work together towards translating basic and applied research into viable technologies," said NSF Program Manager Harsh Deep Chopra. The research also was sponsored by the U.S. Department of Energy, and the Emory-Georgia Tech Nanotechnology Center for Personalized and Predictive Oncology.
[ Back to EurekAlert! ] [ Print Article | E-mail Article | Close Window ]
K.S.Parthasarathy
Public release date: 13-Feb-2008
[ Print Article | E-mail Article | Close Window ]
Contact: Diane Banegas
dbanegas@nsf.gov
703-292-4489
National Science Foundation
Remarkable new clothing may someday power your iPod
The promise of piezoelectric fiber pairs
A schematic illustration of a "bottle-brush " structure shows nanowires arranged around a fiber. The relative "scrubbing " of the two brushes generates electricity.
Click here for more information.
Nanotechnology researchers at the Georgia Institute of Technology are developing a shirt that harvests energy from the wearer's physical motion and converts it into electricity for powering small electronic devices worn by soldiers in the field, hikers and other users.
The research, funded by the National Science Foundation (NSF) and described in the Feb. 14 issue of Nature, details how pairs of textile fibers covered with zinc oxide nanowires generate electricity in response to applied mechanical stress. Known as "the piezoelectric effect," the resulting current flow from many fiber pairs woven into a shirt or jacket could allow the wearer's body movement to power a range of portable electronic devices. The fibers could also be woven into curtains, tents or other structures to capture energy from wind motion, sound vibration or other mechanical energy.
The Georgia Tech research team for fiber nanogenerators: (left to right) Zhong Lin Wang, Xudong Wang and Yong Qin.
Click here for more information.
"The two fibers scrub together just like two bottle brushes with their bristles touching, and the piezoelectric-semiconductor process converts the mechanical motion into electrical energy," Zhong Lin Wang, a Regents professor in the School of Materials Science and Engineering at the Georgia Institute of Technology. "Many of these devices could be put together to produce higher power output."
Wang and collaborators Xudong Wang and Yong Qin have made more than 200 of the fiber nanogenerators. Each is tested on an apparatus that uses a spring and wheel to move one fiber against the other. The fibers are rubbed together for up to 30 minutes to test their durability and power production.
The researchers have measured current of about four nanoamperes and output voltage of about four millivolts from a nanogenerator that included two fibers that were each one centimeter long. With a much improved design, Wang estimates that a square meter of fabric made from the special fibers could theoretically generate as much as 80 milliwatts of power.
So far, there is only one wrinkle in the fabric, so to speak - washing it. Zinc oxide is sensitive to moisture, so in real shirts or jackets, the nanowires would have to be protected from the effects of the washing machine.
###
The research was funded by NSF's Division of Materials Research through grant #0706436. "This multi-disciplinary research grant enables materials scientists and engineers from varied backgrounds to work together towards translating basic and applied research into viable technologies," said NSF Program Manager Harsh Deep Chopra. The research also was sponsored by the U.S. Department of Energy, and the Emory-Georgia Tech Nanotechnology Center for Personalized and Predictive Oncology.
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