Archive | Radiation

Researchers Report Solar Energy Advance

PALO ALTO, Calif., Aug. 2 (UPI) — Scientists say a new process utilizing both the light and heat of solar radiation could double the efficiency of electricity-generating solar panels.

Stanford University researchers say the technology, called “photon enhanced thermionic emission,” could lower the costs of solar energy production to the point where it is competitive with oil as an energy source, a university release said Monday.

Unlike current solar panels, which become less efficient as temperatures rise, panels using the PETE process excel at higher temperatures, the release said.

“This is really a conceptual breakthrough, a new energy conversion process, not just a new material or a slightly different tweak,” Stanford Professor Nick Melosh said. “It is actually something fundamentally different about how you can harvest energy.”

Such devices could be made with cheap and easily available materials, the release said.

Melosh’s team found that coating a piece of semiconducting material with a thin layer of the metal cesium produced a material able to use both light and heat to generate electricity.

“The PETE process could really give the feasibility of solar power a big boost,” Melosh said. “Even if we don’t achieve perfect efficiency, let’s say we give a 10 percent boost to the efficiency of solar conversion, going from 20 percent efficiency to 30 percent — that is still a 50 percent increase overall.”

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Posted in Electricity, Other, Radiation, Solar0 Comments

U.S. Researchers Claim Solar Enegy Advance

PALO ALTO, Calif., Aug. 2 (UPI) — Scientists say a new process utilizing both the light and heat of solar radiation could double the efficiency of electricity-generating solar panels.

Stanford University researchers say the technology, called “photon enhanced thermionic emission,” could lower the costs of solar energy production to the point where it is competitive with oil as an energy source, a university release said Monday.

Unlike current solar panels, which become less efficient as temperatures, panels using the PETE process excel at higher temperatures, the release said.

“This is really a conceptual breakthrough, a new energy conversion process, not just a new material or a slightly different tweak,” Stanford Professor Nick Melosh said. “It is actually something fundamentally different about how you can harvest energy.”

Such devices could be made with cheap and easily available materials, the release said.

Melosh’s team found that coating a piece of semiconducting material with a thin layer of the metal cesium produced a material able to use both light and heat to generate electricity.

“The PETE process could really give the feasibility of solar power a big boost,” Melosh said. “Even if we don’t achieve perfect efficiency, let’s say we give a 10 percent boost to the efficiency of solar conversion, going from 20 percent efficiency to 30 percent; that is still a 50 percent increase overall.”

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

Posted in Electricity, Other, Radiation, Solar0 Comments

Survey Says Biodiversity Down at Chernobyl

PRIPYAT, Russia, July 30 (UPI) — Researchers say a wildlife census in the exclusion zone surrounding the site of the Chernobyl nuclear disaster in Russia shows animal populations are declining.

Professor Timothy Mousseau from the University of South Carolina and Dr. Anders Moller from the University of Paris-Sud, France, spent three years counting and studying animals in the area, the BBC reported Friday.

From 2006 to 2009, they counted and examined wildlife including insects, amphibians, reptiles, birds and mammals.

In a report in the journal Ecological Indicators, they say they found evidence that radiation contamination has a “significant impact” on biodiversity.

“The truth is that these radiation contamination effects were so large as to be overwhelming,” Mousseau said.

The research compared the population of species in the exclusion zone with similar types of habitats in areas that were not contaminated.

Birds provided the best “quantitative measure” of these impacts, the researchers said, noting barn swallows were observed with tumors on their feet, necks and around their eyes.

“We think they may be more susceptible, after their long migrations, to additional environmental stress,” Mousseau said.

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Posted in Amphibians, Biodiversity, Birds, Mammals, Nuclear, Other, Radiation, Reptiles0 Comments

Low-risk Prostate Gets Aggressive Therapy

NEW BRUNSWICK, N.J., July 29 (UPI) — Most men treated for prostate cancer, even if their prostate-specific antigen level and cancer risk are low, receive aggressive treatment, U.S. researchers say.

Yu-Hsuan Shao of the Cancer Institute of New Jersey in New Brunswick and colleagues used data from 123,934 men with newly diagnosed prostate cancer from 2004 to 2006. Fourteen percent had PSA levels of 4 nanograms per milliliter or lower.

“The patients in these cases were less likely to have high-grade cancer, and more than half were classified as having low-risk cancer,” the study authors say in a statement. “Despite their lower risk of having clinically significant disease, treatment rates for men with PSA values of 4 nanograms per milliliter or lower were comparable to those of men presenting with PSA values between 4 and 20 nanograms per milliliter.”

The study, published in the Archives of Internal Medicine, finds more than 70 percent of men with PSA values lower than 20 had their prostates removed via radical prostatectomy or had radiation therapy, 38 percent of men with PSA values between 4.1 and 10.0 and 24 percent of men with PSA values between 10.1 and 20.

“Radiation therapy was performed on 33 percent of men with PSA values of 4.0 nanograms per milliliter or lower, 40 percent of men with PSA values between 4.1 and 10 and 41.3 percent of men with PSA values between 10.1 and 20,” the authors say.

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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Low-risk Prostate Gets Aggressive Therapy

NEW BRUNSWICK, N.J., July 29 (UPI) — Most men treated for prostate cancer, even if their prostate-specific antigen level and cancer risk are low, receive aggressive treatment, U.S. researchers say.

Yu-Hsuan Shao of the Cancer Institute of New Jersey in New Brunswick and colleagues used data from 123,934 men with newly diagnosed prostate cancer from 2004 to 2006. Fourteen percent had PSA levels of 4 nanograms per milliliter or lower.

“The patients in these cases were less likely to have high-grade cancer, and more than half were classified as having low-risk cancer,” the study authors say in a statement. “Despite their lower risk of having clinically significant disease, treatment rates for men with PSA values of 4 nanograms per milliliter or lower were comparable to those of men presenting with PSA values between 4 and 20 nanograms per milliliter.”

he study, published in the Archives of Internal Medicine, finds more than 70 percent of men with PSA values lower than 20 had their prostates removed via radical prostatectomy or had radiation therapy, 38 percent of men with PSA values between 4.1 and 10.0 and 24 percent of men with PSA values between 10.1 and 20.

“Radiation therapy was performed on 33 percent of men with PSA values of 4.0 nanograms per milliliter or lower, 40 percent of men with PSA values between 4.1 and 10 and 41.3 percent of men with PSA values between 10.1 and 20,” the authors say.

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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Researchers Making Fusion Energy Steps

WEST LAFAYETTE, Ind., July 27 (UPI) — U.S. researchers say they’ve made a discovery that could bring nuclear fusion reactors and the possibility of clean, almost limitless power one step closer.

Scientists at Purdue University in West Lafayette, Ind., have made discoveries critical to understanding reactions between hot plasma inside a fusion reactor and surfaces facing the plasma, a university release said Tuesday.

Their aim is to eventually create coatings capable of withstanding the extreme conditions where the lining comes into contact with the extreme heat of the plasma, the release said.

Researchers are using nanotechnology to modify tiny features in the coating in an effort to create new “plasma-facing” materials tolerant to radiation damage, Jean Paul Allain, an assistant professor of nuclear engineering at Purdue, said.

A major challenge in finding the right coatings to line fusion reactors is that materials change due to extreme conditions inside, where temperatures can reach millions of degrees.

A fusion power plant would produce 10 times more energy than a conventional nuclear fission reactor, and because its fuel, deuterium, is contained in seawater, a fusion reactor’s fuel supply would be virtually inexhaustible, researchers say.

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

Posted in Engineering, Other, Radiation0 Comments

'Buckyballs' Found in Distant Star

OSHAWA, Ontario, July 23 (UPI) — Canadian astronomers say they’ve found buckminsterfullerene, also known as buckyballs, one of the strongest molecular structures known on Earth, in outer space.

The molecules were discovered in the remains of a distant star by a University of Ontario team led by astronomer Jan Cami, the online journal Science reported Thursday.

Buckyballs, named because of their resemblance to the geodesic domes of architect Buckminster Fuller, were discovered during experiments on Earth designed to reproduce conditions in space.

It was assumed they’d be found throughout space, but 25 years of searching failed to find them — until Cami and his team started looking at data gathered by NASA’s Spitzer Space Telescope.

“Realizing people have been looking for this for a long time made it quite exciting,” Cami said.

Buckyball molecules, made up of 60 carbon atoms, have been found on Earth in meteorites and some minerals.

“It is one of the most stable, most durable molecules that we know of. Because they are so stable, they can withstand radiation and even cosmic ray bombardments to a certain extent,” said Cami.

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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English Ivy Nanoparticles As Sunblock

KNOXVILLE, Tenn., July 21 (UPI) — English ivy nanoparticles may be key to more effective sunblocks, U.S. researchers suggest.

Researchers at the University of Tennessee at Knoxville say tiny particles secreted from the rootlets of the ivy plant that enable the plant to cling to fences and walls show great promise for use in adhesives and drug delivery and, due to light dispersal qualities, in sunblocks.

“Nanoparticles exhibit unique physical and chemical properties due to large surface-to-volume ratio which allows them to absorb and scatter light,” study leader Zhang says in a statement. “Titanium dioxide and zinc oxide are currently used for sunscreen for the same reason, but the ivy nanoparticles are more uniform than the metal-based nanoparticles, and have unique material properties, which may help to enhance the absorption and scattering of light, and serve better as a sun-blocker.”

Zhang and colleagues say the ivy nanoparticles may help protect skin from UV radiation at least four times better than the metal-based sunblocks now on store shelves.

Besides also being less toxic and more biodegradable, Zhang notes the ivy nanoparticles sunblocks may have two other advantages — being invisible on the skin and requiring less reapplication, because the plant’s nanoparticles adhesiveness may make the sunblock harder to wash off.

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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Beach Umbrellas: Only Partial Sun Block

VALENCIA, Spain, July 21 (UPI) — Thirty-four percent of ultraviolet radiation gets underneath canvas beach umbrellas, researchers in Spain say.

Researchers from the University of Valencia in Spain explain canvas has a very high capacity for absorbing radiation and intercepts most full direct sun rays. However, they say, the umbrella does not protect from the diffused radiation that penetrates through from the sides.

The study, published in the journal Photochemistry and Photobiology, finds part of the diffused radiation that makes up approximately 60 percent of the total reached a sensor positioned under the umbrella.

“We have proven that irradiance — radiation incidence per unit of surface area — that reaches the ground covered by an umbrella is 34 percent of the total,” study co-author Jose Antonio Martinez-Lozano says in a statement.

Martinez-Lozano and colleagues positioned an ultraviolet ray sensor on the base of a canvas beach umbrella painted blue and white and also developed a geometric model.

The model calculated the irradiance received on the different horizontal and vertical planes under the umbrella. In the case of horizontal irradiance, the values the model provides coincide with those registered experimentally with a relative error of 3 percent.

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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Protection from High-dose Radiation

DENVER, July 19 (UPI) — A U.S. radiology expert says healthcare providers are finding ways to protect patients from high-dose radiation.

Dr. Simeon Abramson, lead heart computed tomography radiologist at Denver’s Porter Adventist Hospital, says concern about the health risks of commonly used scanning tests involving high doses of radiation has led doctors and technicians to seek ways of decreasing radiation exposure.

At Porter, Abramson and colleagues have succeeded in reducing the dose of radiation for computed tomography heart scans from the equivalent of 100 to 140 chest X-rays to the equivalent of 10 to 30 X-rays. This is done in part by turning off the X-ray during parts of the rotation that target sensitive areas, such as organs.

“We learned that it was possible to use software within our system that allowed us to reduce the radiation exposure in CT heart scans for most of our patients. The quality of the image has not been affected and we know that we are protecting our patients from potential harmful doses.” Abramson says in a statement.

Copyright 2010 United Press International, Inc. (UPI). Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI’s prior written consent.

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