Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: electronics – Page 53

Electrons are very much at the mercy of magnetic fields, which scientists can manipulate to control the electrons and their angular momentum—i.e. their “spin.”

A Cornell team led by Greg Fuchs, assistant professor of applied and engineering physics in the College of Engineering, in 2013 invented a new way to exert this control by using acoustic waves generated by mechanical resonators. That approach enabled the team to control electron spin transitions (also known as spin resonance) that otherwise wouldn’t be possible through conventional magnetic behavior.

The finding was a boon for anyone looking to build quantum sensors of the sort used in mobile navigation devices. However, such devices still required a magnetic control field—and therefore a bulky magnetic antenna—to drive certain spin transitions.

Read more | >

Imagine working in the hot streets of Manila in the early 1990s. You are a butcher, slaving away in a loud, humid market for long hours. You only make several dollars a day to support a large family.

One evening, you are holding a Pepsi bottle cap in your hand. On it is a number. You bought several of these sodas in hopes of winning a big $40,000 giveaway at the end of the promotion. This money could change your family’s life. It is a mountain of earnings in a world of limited opportunities. You watch as Pepsi begins reading off the winners on TV.

Suddenly, you realize you’ve won. Incredulous, you quadruple check your numbers. The number is accurate. Your heart begins racing as you rush to call your wife and kids. However, you, and many winners like you, will never see that money. But at least you won’t lose your life, like some.

Read more | >

Acoustic waves have been found to be highly versatile and promising carriers of information between chip-based electronic devices. This characteristic is ideal for the development of a number of electronic components, including microwave filters and transducers.

In the past, some researchers have tried to build devices in which waves are transmitted between two ports in a non-symmetric way. These are known as nonreciprocal devices. These devices could be particularly promising for the manipulation and routing of phonons, quasiparticles associated with . Building nonreciprocal devices that transmit acoustic waves, however, can be highly challenging, as typically transmit waves in a linear way.

Researchers at Harvard University have recently achieved the non-reciprocal transmission of non-reciprocal acoustic waves using a nonlinear parity-time symmetric system. This system, presented in a paper published in Nature Electronics, is based on two coupled acoustic resonators placed on a lithium niobate surface.

Read more | >

This paper describes the design, implementation, and evaluation of VanarSena, an automated fault finder for mobile applications (“apps’‘). The techniques in VanarSena are driven by a study of 25 million real-world crash reports of Windows Phone apps reported in 2012. Our analysis indicates that a modest number of root causes are responsible for many observed failures, but that they occur in a wide range of places in an app, requiring a wide coverage of possible execution paths. VanarSena adopts a “greybox’’ testing method, instrumenting the app binary to achieve both coverage and speed. VanarSena runs on cloud servers: the developer uploads the app binary; VanarSena then runs several app “monkeys’’ in parallel to emulate user, network, and sensor data behavior, returning a detailed report of crashes and failures. We have tested VanarSena with 3000 apps from the Windows Phone store, finding that 1108 of them had failures; VanarSena uncovered 2969 distinct bugs in existing apps, including 1227 that were not previously reported. Because we anticipate VanarSena being used in regular regression tests, testing speed is important. VanarSena uses two techniques to improve speed. First, it uses a “hit testing’’ method to quickly emulate an app by identifying which user interface controls map to the same execution handlers in the code. Second, it generates a ProcessingCompleted event to accurately determine when to start the next interaction. These features are key benefits of VanarSena’s greybox philosophy.

2014-06

http://hdl.handle.net/1721.1/110759

Read more | >

Circa 2011

Scientists at M.I.T’s Media lab have created a camera that can capture the speed of light, taking a photo in less than two-trillionths of a second. Using multiple cameras, sensors, a pulse light source and mirrors, the researchers create slow motion movies of light moving through objects and liquids. They call the technique femto-photography. “We have built a virtual slow motion camera where we can see photons, or light particles through space,” said Associate Professor Ramesh Raskar in an video interview. “Photons travel about a million times photons travel a million times faster than bullets. So our camera can see photons, or bullets of light traveling through space.”

Read more | >

Most preppers are not in fact preparing for doomsday – they’re everyday people who anticipate and try to adapt for many conditions of calamity; conditions that they believe are inevitable and have been exponentially escalated through human hubris and excessive reliance on technology and global trade networks. While the disasters they anticipate might – at the more extreme end of the spectrum – include major “resets” like an all-out nuclear war or a massive electromagnetic pulse from the Sun that would fry our fragile electronics, most preppers stockpile for low to mid-level crises like the one the world is experiencing now.

For some, the current crisis is a dummy run for long-term lockdown. Across the world, luxury bunkers are being built for a lucky few to survive calamity and collapse.

Read more | >

Researchers have created a device called a ‘shadow-effect energy generator’ that makes use of the contrast in illumination between lit and shadowed areas to generate electricity. This novel concept opens up new approaches in harnessing indoor lighting conditions to power electronics.

Shadows are often associated with darkness and uncertainty. Now, researchers from the National University of Singapore (NUS) are giving shadows a positive spin by demonstrating a way to harness this common but often overlooked optical effect to generate electricity.

“Shadows are omnipresent, and we often take them for granted. In conventional photovoltaic or optoelectronic applications where a steady source of light is used to power devices, the presence of shadows is undesirable, since it degrades the performance of devices. In this work, we capitalised on the illumination contrast caused by shadows as an indirect source of power. The contrast in illumination induces a voltage difference between the shadowed and illuminated sections, resulting in an electric current. This novel concept of harvesting energy in the presence of shadows is unprecedented,” explained research team leader Assistant Professor Tan Swee Ching, who is from the NUS Department of Materials Science and Engineering.

Read more | >

Current methods for charging electronic devices via wireless technology only work if the overall system parameters are set up to match a specific transfer distance. As a result, these methods are limited to stationary power transfer applications, which means that a device that is receiving power needs to maintain a specific distance from the source supplying it in order for the power transfer to be successful.

Researchers at Stanford University have recently developed a new technique that could enable more efficient wireless transfer regardless of the distance between a device and its power source. Their paper, published in Nature Electronics, could help to overcome some of the current limitations of existing tools for the wireless charging of elecronic devices.

“The main purpose of our study was to overcome the barrier to dynamic wireless charging,” Sid Assawaworrarit, one of the researchers who carried out the study, told Phys.org. “Our idea is based on parity-time symmetry (PT symmetry), which concerns systems with balanced gain and loss.”

Read more | >