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Sensors Provide Early Diagnosis Of Microcracks In Aircraft |
 Today's aircraft are in service virtually around the clock and must operate reliably and safely at all times. An active sensor system helps to detect concealed fatigue cracks in aircraft bodies, thus reducing maintenance times considerably.
If a tiny crack in the hull of an aircraft remains undetected for a long time, it can easily spread and put passengers’ lives at risk. Each component is therefore subject to international maintenance regulations: Aircraft bodies must be thoroughly inspected every 15 to 18 months, depending on the type of plane. This often requires the technicians to dismantle an aircraft’s interior lining – an expensive and time-consuming process involving several days of downtime in the hangar. Researchers at the Fraunhofer Institute for Structural Durability and System Reliability LBF in Darmstadt are developing a sensor system that allows engineers to continuously monitor the condition of their aircraft and detect any damage at an early stage.
The system is based on piezoceramic sensors that are attached to the aircraft body in a network pattern. What is special about these sensors is that they start to oscillate when a voltage is applied to them – and when they are subjected to pressure, they generate voltage. The scientists make use of both effects: While the piezo foils cause part of the hull to oscillate, the others measure the component’s response to this stimulation. “We investigated the oscillation behavior of damaged struts and rivets in an aircraft body and compared it with that of intact parts,” explains LBF project manager Dirk Mayer. “If a component is defective, it oscillates at a different frequency from one that is intact when stimulated by the piezoceramics – just as a cracked glass sounds different from an undamaged one when you tap it with your fingernail.” In this way, the researchers can accurately track down faults and monitor their development – be it fatigue cracks in the hull and wings, or rivets and other joining parts coming loose. This form of observation is also referred to as ‘structural health monitoring’ (SHM).
“With the help of this system, any damage behind the lining or in difficult-to-reach places can be identified quickly and easily, thus reducing maintenance times and inspection costs,” says Mayer. The researchers have already performed tests on a hull component in the laboratory, and are now implementing the new technology with standardized piezo and electronic components. The system will then also be suitable for use in vehicle manufacture or engine and plant construction.
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Dear Editor,
I hope you can help me or at least point me in the right direction. My neighbor just put up a huge CB Radio antennea, the thing is higher that the roof of his home, the problem is, now I have interference through our television set speakers. We can hear him speaking although it is not too clear. How can I fix the problem so that we can watch t.v. without hearing this noise? Any help you can give me would be greatly appreciated.
Sincerly,
Donna R.
Dear Donna,
If your neighbor's transmissions are interfering with your TV, the best thing for you to do is complain to the Federal Communications Commission. The FCC investigates cases of interference and they will determine if your neighbor's transmissions contain out-of-band signals. You might also try talking to your neighbor. If his antenna is for amateur radio rather than Citizens Band, "ham" radio operators have a policy of supplying a free filter for your TV in such cases.
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ElectronicDesignNet News
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We scan the wires, web sites, blogs and news media for the most interesting and relevant information, then summarize it for you in a convenient format, organized by topic areas during the week:
You can stay on top of things without wasting your precious time sifting through lots of noise. Subscribe to our digest and receive it in your eMail, or come to our site and read it in your web browser. Digest eMail subscriptions can be managed on the Newsletters tab of the "My Settings - Edit Profile" page once you register.
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Introduction To The Challenges Of Low-Power RF Mesh Networks |
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Product Design - Wednesday
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Friday, 11 May 2007 |
Software must have the flexibility to support a variety of underlying hardware choices and a comprehensive operating environment designed for robustness, resilience and reliability. One of the potentially highest growth segments in the world of wireless networking has until recently, also been one of the least noticed. While media attention and industry buzz has primarily focused on Wi-Fi, Bluetooth and other "high end" consumer oriented networking, the segment known as low-power wireless (LPW) mesh networking has steadily been carving out a wide range of application possibilities and getting set for a period of potentially enormous growth....more  (0) Comments |
A Practical Guide To Low Power Efficiency Measurements |
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Test & Measurement / Data Acquisition - Tuesday
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Friday, 11 May 2007 |
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Find out how to make accurate low power mode measurements to get the highest efficiencies. Overall system efficiency is a critical design parameter in battery powered systems. It affects both the battery capacity requirement and the end product's run time. Proper system efficiency and run time calculations can be achieved only when the power supply's efficiency measurements are accurate. Most battery powered systems take advantage of a power supply feature called pulse frequency modulation (PFM) to improve power supply efficiency at light loads. The same characteristics that help PFM mode achieve high power supply efficiencies also create several challenges for properly measuring the efficiency....more (0) Comments |
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National Instruments Offers Free Mechatronics Resources |
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Product Design - Wednesday
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Friday, 11 May 2007 |
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Mechatronics is a system-level approach to designing electromechanical systems that merges mechanical, electrical, control system, and embedded software design. It represents an industry-wide effort to improve the design process by integrating the best available development practices and technologies to streamline design, prototyping, and deployment....more (0) Comments |
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Wireless USB The Key Development In 2007 USB Market |
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Business News - Monday
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Friday, 11 May 2007 |
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The Universal Serial Bus (USB) saw continued success in 2006, but 2007 is going to be a milestone as wireless USB (WUSB) products are expected to hit the market around mid-year, reports In-Stat. The initial WUSB products will be dongle and hub solutions that will allow PCs to wirelessly connect to PC peripherals and CE devices, the high-tech market research firm says. Integrated solutions with Certified WUSB capability inside the box will come in a few devices before the end of 2007, including PCs, printers, multi-function peripherals (MFPs) and digital still cameras....more (0) Comments |
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