Thursday, January 31, 2019

Smartphones that can be powered by Wi-Fi signals; scientists working on battery-less devices

Smartphones won't need batteries to power them as a team of US-based scientists have development a new device named ‘rectenna’ which will use Wi-Fi signals to power phones, laptops, wearable technology and more

Smartphones have come a long way in the last half a decade or so and every year, we see new technologies being implemented in these cellular devices with all major players battling it out for getting the first mover’s advantage. That said, have you ever thought of using a smartphone so ‘smart’ that it won’t even need a battery to power itself. The thought might not seem like a reality to you but in a recent development, scientists have come up with a cellular device named ‘rectenna’ which can offer battery-less power for laptops, smartphones, wearable technology and medical devices.

smartphones battery Smartphones can be powered by Wi-Fi signals
Smartphones have come a long way in the last half a decade or so and every year, we see new technologies being implemented in these cellular devices with all major players battling it out for getting the first mover’s advantage. That said, have you ever thought of using a smartphone so ‘smart’ that it won’t even need a battery to power itself. The thought might not seem like a reality to you but in a recent development, scientists have come up with a cellular device named ‘rectenna’ which can offer battery-less power for laptops, smartphones, wearable technology and medical devices.

Professor Tomas Palacios, who is the director of the Massachusetts Institute of Technology as well as the Microsystems Technology Laboratories Centre for Graphene Devices and 2D Systems, along with his team has developed ‘rectenna’ which uses a flexible material that is capable of converting radio signals into usable electric current which offers offer battery-less power for laptops, smartphones and more.

 "What if we could develop electronic systems that we wrap around a bridge or cover an entire highway, or the walls of our office and bring electronic intelligence to everything around us? How do you provide energy for those electronics?” Professor Tomas Palacios was quoted as saying by the Daily Record. On the other hand, the research and details about ‘rectenna’ have been published in the recent online issue of the journal Nature.

In order to create rectenna, the team of scientists used a 2D material named molybdenum disulphide, which is considered to be one of the thinnest semiconductors with a thickness of just three atoms. Wi-Fi signals are captured by an integrated antenna in the system which are then transformed into a DC current. The electricity is obtained in form of radio waves which comes in high-frequency alternating current (AC).

The semiconductor in ‘rectenna’ converts the AC signal to direct current which can be used to offer battery-less power for laptops, smartphones and more. In experiments, rectenna was able to generate around 40 microwatts of power while being exposed to wi-fi signals with a frequency of around 150 microwatts. That much power is more than enough to power a simple smartphone or even activate silicon chips.

Wednesday, January 30, 2019

To Catch a Wave, Rocket Launches From Top of World

On Jan. 4, 2019, at 4:37 a.m. EST the CAPER-2 mission launched from the Andøya Space Center in Andenes, Norway, on a 4-stage Black Brant XII sounding rocket. Reaching an apogee of 480 miles high before splashing down in the Arctic Sea, the rocket flew through active aurora borealis, or northern lights, to study the waves that accelerate electrons into our atmosphere.

CAPER-2, short for Cusp Alfvén and Plasma Electrodynamics Rocket-2, is a sounding rocket mission — a type of spacecraft that carries scientific instruments on short, targeted trips to space before falling back to Earth. In addition to their relatively low price tags and quick development time, sounding rockets are ideally suited for launching into transient events — like the sudden formation of the aurora borealis, or northern lights.

animation of sounding rocket trajectory thru aurora
Sounding rockets are well-suited for studying the fundamental physics of the northern lights.
Credits: NASA
For CAPER-2 scientists, flying through an aurora provides a peek into a process as fundamental as it is complex: How do particles get accelerated throughout space? NASA studies this phenomenon in an effort to better understand not only the space environment surrounding Earth — and thus protect our technology in space from radiation — but also to help understand the very nature of stars and atmospheres throughout the solar system and beyond.

“Throughout the universe you have charged particles getting accelerated — in the Sun’s atmosphere, in the solar wind, in the atmospheres of other planets, and in astrophysical objects,” said Jim LaBelle, space physicist at Dartmouth College in Hanover, New Hampshire, and principal investigator for the CAPER-2 mission. “An aurora presents us with a local laboratory where we can observe these acceleration processes close at hand.”

Technically, the CAPER-2 team is interested in what happens just before an aurora starts glowing. Electrons, pouring into our atmosphere from space, collide with atmospheric gases and trigger the aurora’s glow. Somehow, they pick up speed along the way.

“By the time they crash into our atmosphere, these electrons are traveling over 10 times faster than they were before,” said Doug Rowland, space physicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who also studies particle acceleration. “We still don’t understand the fundamental physics of how that happens.”

The CAPER-2 team focused on a special kind of aurora that forms during the day. Unlike the nighttime aurora, the daytime aurora is triggered by electrons that stream in directly from the Sun — and we know far less about them.


“There’s been a huge amount of research done on the regular nighttime aurora, but the daytime aurora is much less studied,” said Craig Kletzing, space physicist at the University of Iowa in Iowa City and coinvestigator for the mission. “There are good indications that there are some similarities and there are also some differences.”

The team is focusing on how the electrons that create daytime auroras are jostled around by waves, in ways that may or may not differ from nighttime auroras. Two kinds of waves are of special interest, and have opposite effects. Alfvén waves, named after Swedish Nobel laureate Hannes Alfvén who first predicted their existence in 1942, are thought to accelerate the electrons. These huge waves — measuring tens to hundreds of miles long from peak to peak — propagate along Earth’s magnetic field lines, whipping electrons to and fro.

On the other side are Langmuir waves, which are generated by the electrons themselves — a process that steals some of the electrons’ energy and slows them down. CAPER-2 will carry a high-resolution wave-particle correlator to measure them, the first sounding rocket mission to do so for the daytime aurora.

“This is very data-intensive,” said LaBelle. “It’s unique to sounding rockets to be able to look at this mechanism in this level of detail.”

For the launch, the CAPER-2 team traveled to northern Norway, one of the few places that can put a rocket within range of the daytime aurora. Every day, northern Norway rotates under an opening in Earth’s magnetic field known as the northern polar cusp, where particles from the Sun can funnel into our upper atmosphere.
illustration of Earth's magnetosphere
Earth’s magnetosphere, showing the northern and southern polar cusps (illustration).
Credits: Andøya Space Center/Trond Abrahamsen
Meeting the aurora right where they form is the best way to understand physical processes that are far too large to replicate in a lab.

“It’s a kind of natural laboratory,” LaBelle added. “We take our experiment to two different environments, where the variables are different, and then test the theory and answer the questions.”
CAPER-2 was the third of nine sounding rocket missions taking part in the Grand Challenge Initiative – Cusp, an international campaign to explore the northern polar cusp. The VISIONS-2 and TRICE-2 missions launched in early December, and the fourth mission, G-CHASER, launched on Jan. 13. The window for AZURE, the next mission in the Grand Challenge Initiative – Cusp, opens on March 23, 2019.



All Systems Go As Parker Solar Probe Begins Second Sun Orbit

On Jan. 19, 2019, just 161 days after its launch from Cape Canaveral Air Force Station in Florida, NASA’s Parker Solar Probe completed its first orbit of the Sun, reaching the point in its orbit farthest from our star, called aphelion. The spacecraft has now begun the second of 24 planned orbits, on track for its second perihelion, or closest approach to the Sun, on April 4, 2019.

Parker Solar Probe entered full operational status (known as Phase E) on Jan. 1, with all systems online and operating as designed. The spacecraft has been delivering data from its instruments to Earth via the Deep Space Network, and to date more than 17 gigabits of science data has been downloaded. The full dataset from the first orbit will be downloaded by April.

“It’s been an illuminating and fascinating first orbit,” said Parker Solar Probe Project Manager Andy Driesman, of the Johns Hopkins University Applied Physics Laboratory. “We’ve learned a lot about how the spacecraft operates and reacts to the solar environment, and I’m proud to say the team’s projections have been very accurate.” APL designed, built, and manages the mission for NASA.

“We’ve always said that we don’t know what to expect until we look at the data,” said Project Scientist Nour Raouafi, also of APL. “The data we have received hints at many new things that we’ve not seen before and at potential new discoveries. Parker Solar Probe is delivering on the mission’s promise of revealing the mysteries of our Sun.”

Parker Solar Probe’s position, speed and round-trip light time as of Jan. 28, 2019. Track the spacecraft online.
The Parker Solar Probe team is not only focused on analyzing the science data but also preparing for the second solar encounter, which will take place in about two months.

In preparation for that next encounter, the spacecraft’s solid state recorder is being emptied of files that have already been delivered to Earth. In addition, the spacecraft is receiving updated positional and navigation information (called ephemeris) and is being loaded with a new automated command sequence, which contains about one month’s worth of instructions.

Astronomers Find Dark Energy May Vary Over Time

A new study using data from NASA's Chandra X-ray Observatory and ESA's XMM-Newton suggests that dark energy may have varied over cosmic time, as reported in our latest press release. This artist's illustration helps explain how astronomers tracked the effects of dark energy to about one billion years after the Big Bang by determining the distances to quasars, rapidly growing black holes that shine extremely brightly.

First discovered about 20 years ago by measuring the distances to exploded stars called supernovas, dark energy is a proposed type of force, or energy, that permeates all space and causes the expansion of the Universe to accelerate. Using this method, scientists tracked the effects of dark energy out to about 9 billion years ago.

The latest result stems from the development of a new method to determine distances to about 1,598 quasars, which allows the researchers to measure dark energy's effects from the early Universe through to the present day. Two of the most distant quasars studied are shown in Chandra images in the insets.

The new technique uses ultraviolet (UV) and X-ray data to estimate the quasar distances. In quasars, a disk of matter around the supermassive black hole in the center of a galaxy produces UV light (shown in the illustration in blue). Some of the UV photons collide with electrons in a cloud of hot gas (shown in yellow) above and below the disk, and these collisions can boost the energy of the UV light up to X-ray energies. This interaction causes a correlation between the amounts of observed UV and X-ray radiation. This correlation depends on the luminosity of the quasar, which is the amount of radiation it produces.

Using this technique the quasars become standard candles, as implied by the artist's illustration. Once the luminosity is known, the distance to the quasars can be calculated from the observed amount of radiation.

The researchers compiled UV data for 1,598 quasars to derive a relationship between UV and X-ray fluxes, and the distances to the quasars. They then used this information to study the expansion rate of the universe back to very early times, and found evidence that the amount of dark energy is growing with time.

Since this is a new technique, the astronomers took extra steps to show that this method gives reliable results. They showed that results from their technique match up with those from supernova measurements over the last 9 billion years, giving them confidence that their results are reliable at even earlier times. The researchers also took great care in how their quasars were selected, to minimize statistical errors and to avoid systematic errors that might depend on the distance from Earth to the object.

A paper on these results appears in Nature Astronomy on January 28, 2019, by Guido Risaliti (University of Florence, Italy) and Elisabeta Lusso (Durham University, United Kingdom). It is available online at https://arxiv.org/abs/1811.02590

NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.

Image credit: NASA/CXC/Univ. of Florence/G.Risaliti & E.Lusso

Curiosity Says Farewell to Mars' Vera Rubin Ridge

A selfie taken by NASA's Curiosity Mars rover on Sol 2291 (January 15) at the "Rock Hall" drill site, located on Vera Rubin Ridge.
Credits: NASA/JPL-Caltech/MSSS
Full image and caption
NASA's Curiosity rover has taken its last selfie on Vera Rubin Ridge and descended toward a clay region of Mount Sharp. The twisting ridge on Mars has been the rover's home for more than a year, providing scientists with new samples — and new questions — to puzzle over.

On Dec. 15, Curiosity drilled its 19th sample at a location on the ridge called Rock Hall. On Jan. 15, the spacecraft used its Mars Hand Lens Imager (MAHLI) camera on the end of its robotic arm to take a series of 57 pictures, which were stitched together into this selfie. The "Rock Hall" drill hole is visible to the lower left of the rover; the scene is dustier than usual at this time of year due to a regional dust storm.

Curiosity has been exploring the ridge since September of 2017. It's now headed into the "clay-bearing unit," which sits in a trough just south of the ridge. Clay minerals in this unit may hold more clues about the ancient lakes that helped form the lower levels on Mount Sharp.

NASA's Curiosity Rover Snaps Last Selfie on Martian Ridge


After spending more than a year on a twisting ridge on Mars, NASA's Curiosity rover has snapped its last selfie as it moves on to new sights on the Red Planet

"Curiosity rover has taken its last selfie on the Vera Rubin Ridge and descended toward a clay region of Mount Sharp. The twisting ridge on Mars has been the rover's home for more than a year, providing scientists with new samples and new questions to puzzle over," NASA said in a statement on Monday.

On January 15, Curiosity used its Mars Hand Lens Imager (MAHLI) camera on the end of its robotic arm to take a series of 57 pictures, which were stitched together into the selfie.

The images feature a location on the ridge called Rock Hall, which the rover drilled on December 15.

The Rock Hall drill hole is visible to the lower left of the rover; the scene is dustier than usual at this time of the year due to a regional dust storm.

Curiosity has been exploring the ridge since September 2017.

It is now heading into the "clay-bearing unit", which sits in a trough just south of the ridge.

Clay minerals in this unit may hold more clues about the ancient lakes that helped form the lower levels on Mount Sharp, NASA said.

Curiosity, which landed on Mars in 2012, was designed to assess whether Mars ever had an environment able to support small life forms called microbes. In other words, its mission is to determine the planet's "habitability".

New AI-enabled tool may translate thoughts into speech

The study, led by Columbia University researchers, showed that by monitoring one's brain activity, an AI-enabled technology could reconstruct words a person hears with unprecedented clarity, Xinhua news agency
New York: US engineers developed an Artificial Intelligence (AI)-enabled system that can translate brain signals into intelligible speech, a breakthrough that may help those who cannot speak to communicate with the outside world. The study, led by Columbia University researchers, showed that by monitoring one's brain activity, an AI-enabled technology could reconstruct words a person hears with unprecedented clarity, Xinhua news agency reported.

A team of neuroscientists from the varsity trained a voice synthesiser or vocoder to measure brain activity patterns of epilepsy patients already undergoing surgery while those patients listened to sentences spoken by different people. Those patients listened to speakers reading digits between zero to nine while recording brain signals via the vocoder.
Then, they used a neural network, a type of artificial intelligence, to analyse the signals, and gave robotic-sounding voices, according to the study published in the journal Scientific Reports.

"We found that people could understand and repeat the sounds about 75 per cent of the time, which is well above and beyond any previous attempts," said Nima Mesgarani from the varsity.

Previous research showed that when people speak or even imagine speaking, distinct patterns of activity take place in their brain and those pattern of signals also emerge when we listen to someone talk or imagine listening.

Mesgarani and his team planned to test more complicated words and to run the same tests on brain signals emitted when a person speaks or imagines speaking. Mesgarani called it a "game changer" that may give anyone who has lost their ability to speak a new chance to connect to the outside world.

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Smartphones that can be powered by Wi-Fi signals; scientists working on battery-less devices

Smartphones won't need batteries to power them as a team of US-based scientists have development a new device named ‘rectenna’ which wi...