Next few days will be interesting with price testing 200 days EMA and the $11 resistance line.Successful breakout above $11 will cause price movement towards the next resistance level at $12. However, should this breakout fail price will probably retrace back to gap support at $9.30.
Dark-field x-ray imaging could make for more-accurate mammograms and better security screens.
Swiss researchers have demonstrated the practicality of a new high-resolution x-ray imaging technique that reveals fine structures that are invisible using conventional techniques. Dark-field x-ray imaging can be used to generate highly detailed images of bones and to distinguish between substances that look identical in conventional x-ray images, such as explosives and cheese. The researchers are now investigating whether their approach might also increase the resolution of medical imaging techniques such as mammograms and computed-tomography (CT) scans.
Franz Pfeiffer, assistant professor of physics at Ecole Polytechnique Fédérale de Lausanne, in Switzerland, who developed the new technique, compares conventional x-ray images with shadows. Such images rely on information about how much radiation is absorbed as it passes through a sample, such as a patient's limb. But more-complex interactions are happening, says Pfeiffer, and the more information that can be gleaned about these interactions, the better the contrast of the images. Dark-field imaging measures how a sample scatters light.
"These guys are showing that you can do things with x-rays that were only thought practical optically [with visible light]," says Richard Lanza, a senior research scientist at MIT's department of nuclear science and engineering.
Previously, researchers including Pfeiffer had demonstrated dark-field imaging using a large, expensive particle accelerator called a synchrotron as an x-ray source. Synchrotrons provide very bright, finely focused beams of x-rays. Such a powerful source was necessary because the inefficient crystal optics used to focus the x-rays onto the sample could only cope with a narrow spectrum of wavelengths.
To replace the inefficient crystal optics, Pfeiffer developed silicon filters that work with the full spectrum of rays generated by low-power, conventional x-ray tubes. These filters are flat discs of silicon etched with 20-micrometer-long slits, some of which are filled with gold. To generate scattering images, these grates are placed between the x-ray source and the sample, and between the sample and the detector.
"Small structures like micro-cracks show up nicely in these images because they scatter radiation quite a bit," says Pfeiffer. This suggests that the images could be useful for detecting osteoporosis or for finding flaws in mechanical structures such as turbines.
"Edges and boundaries are more clear in the dark-field images," says Elizabeth Brainerd, an evolutionary biologist at Brown University, who uses x-rays to study the biomechanics of bones.
(See "Catching Evolution on the Run.") It can be difficult to distinguish small bones and joints in conventional x-rays. Brainerd agrees that dark-field images could be useful for detecting small fractures and bone spurs in patients, and she's excited about the possibility of extending Pfeiffer's technique to three-dimensional CT scans.
Pfeiffer's approach could be used to improve security systems too. Conventional x-ray imagers like those at airport-security checkpoints can't differentiate between many different kinds of materials--for example, chocolate and cheese appear identical to some explosives. But cheese and explosives scatter x-rays differently, so in Pfeiffer's dark-field images, the differences between the two materials are apparent.
Pfeiffer has already begun making CT scans with conventional x-ray tubes using another contrast-enhancing technique he developed two years ago, called phase contrast. He says that he's currently working to incorporate gratings for dark-field imaging into conventional CT devices. He's also collaborating with researchers at the Center for Biomedical Imaging, an institute run by the University of Lausanne and the University of Geneva, to determine whether dark-field x-ray imaging can be used to tell healthy tissue from cancerous tissue. Cancers don't absorb x-rays very differently than healthy tissue does, so x-ray systems that rely on other properties, such as scattering, might make for better mammograms, for example. Lanza's group at MIT is also working to develop better cancer-detecting CT scanners that use a combination of absorption and refraction for contrast and also rely on nanofabricated gratings. (See "Changing the Physics behind X-Ray Imaging.")
Dark-field imaging has been used for more than 20 years to enhance contrast and resolution in conventional optical microscopes. But applying the contrast-enhancing techniques that work well with visible light to x-rays has taken a long time, says Pfeiffer. Such a system is only now possible thanks to advances in photolithography and many years of basic science research using synchrotrons, he says.
Pfeiffer envisions that future x-ray imaging systems will be like what light microscopes are today: they will incorporate many complementary systems for enhancing contrast--absorption, refraction, scattering--and doctors and researchers will be able to use whichever combination works best for a given sample.
http://www.technologyreview.com/Nanotech/20104/page2/
Thermography, thermal imaging, or thermal video, is a type of infrared imaging. Thermographic cameras detect radiation in the infrared range of the electromagnetic spectrum (roughly 900–14,000 nanometers or 0.9–14 µm) and produce images of that radiation. Since infrared radiation is emitted by all objects based on their temperatures, according to the black body radiation law, thermography makes it possible to "see" one's environment with or without visible illumination. The amount of radiation emitted by an object increases with temperature, therefore thermography allows one to see variations in temperature (hence the name). When viewed by thermographic camera, warm objects stand out well against cooler backgrounds; humans and other warm-blooded animals become easily visible against the environment, day or night. As a result, thermography's extensive use can historically be ascribed to the military and security services.
Thermal imaging photography finds many other uses. For example, firefighters use it to see through smoke, find persons, and localize the base of a fire. With thermal imaging, power lines maintenance technicians locate overheating joints and parts, a telltale sign of their failure, to eliminate potential hazards. Where thermal insulation becomes faulty, building construction technicians can see heat leaks to improve the efficiencies of cooling or heating air-conditioning. Thermal imaging cameras are also installed in some luxury cars to aid the driver, the first being the 2000 Cadillac DeVille. Some physiological activities, particularly responses, in human beings and other warm-blooded animals can also be monitored with thermographic imaging. [1]
The appearance and operation of a modern thermographic camera is often similar to a camcorder. Enabling the user to see in the infrared spectrum is a function so useful that ability to record their output is often optional. A recording module is therefore not always built-in.
Instead of CCD sensors, most thermal imaging cameras use CMOS Focal Plane Array (FPA). The most common types are InSb, InGaAs, HgCdTe and QWIP FPA. The newest technologies are using low cost and uncooled microbolometers FPA sensors. Their resolution is considerably lower than of optical cameras, mostly 160x120 or 320x240 pixels, up to 640x512 for the most expensive models. Thermographic cameras are much more expensive than their visible-spectrum counterparts, and higher-end models are often export-restricted. Older bolometers or more sensitive models as InSb require cryogenic cooling, usually by a miniature Stirling cycle refrigerator or liquid nitrogen.
http://en.wikipedia.org/wiki/Thermal_imaging
