Better battery imaging paves way for renewable energy future

 

Chemical phase map showing how the electrochemical discharge of iron fluoride microwires proceeded from 0 percent discharge (left), to 50 percent (middle), to 95 percent. Image: Linsen Li In a move that could improve the energy storage of everything from portable electronics to electric microgrids, University of Wisconsin-Madison and Brookhaven National Laboratory researchers have developed a novel X-ray imaging technique to visualize and study the electrochemical reactions in lithium-ion rechargeable batteries containing a new type of material, iron fluoride. "Iron fluoride has the potential to triple the amount of energy a conventional lithium-ion battery can store," says Song Jin, a UW-Madison professor of chemistry and Wisconsin Energy Institute affiliate. "However, we have yet to tap its true potential." Song Jin Graduate student Linsen Li worked with Jin and other collaborators to perform experiments with a state-of-the-art transmission X-ray microscope at the National Synchrotron Light Source at Brookhaven. There, they collected chemical maps from actual coin cell batteries filled with iron fluoride during battery cycling to determine how well they perform. The results are published today in the journal Nature Communications. "In the past, we weren't able to truly understand what is happening to iron fluoride during battery reactions because other battery components were getting in the way of getting a precise image," says Li. By accounting for the background signals that would otherwise confuse the image, Li was able to accurately visualize and measure, at the nanoscale, the chemical changes iron fluoride undergoes to store and discharge energy. Thus far, using iron fluoride in rechargeable lithium ion batteries has presented scientists with two challenges. The first is that it doesn't recharge very well in its current form. "This would be like your smart phone only charging half as much the first time, and even less thereafter," says Li. "Consumers would rather have a battery that charges consistently through hundreds of charges." Linsen Li By examining iron fluoride transformation in batteries at the nanoscale, Jin and Li's new X-ray imaging method pinpoints each individual reaction to understand why capacity decay may be occurring. "In analyzing the X-ray data on this level, we were able to track the electrochemical reactions with far more accuracy than previous methods, and determined that iron fluoride performs better when it has a porous microstructure," says Li. The second challenge is that iron fluoride battery materials don't discharge as much energy as they take in, reducing energy efficiency. The current study yielded some preliminary insights into this problem and Jin and Li plan to tackle this challenge in future experiments. Some implications of this research are obvious — like using portable electronic devices for longer before charging — but Jin also foresees a bigger and broader range of applications. "If we can maximize the cycling performance and efficiency of these low-cost and abundant iron fluoride lithium ion battery materials, we could advance large-scale renewable energy storage technologies for electric cars and microgrids," he says. Jin also believes that the novel X-ray imaging technique will facilitate the studies of other technologically important solid-state transformations and help to improve processes such as preparation of inorganic ceramics and thin-film solar cells. The experiments were performed with the help of Yu-chen Karen Chen-Wiegart, Feng Wang, Jun Wang and their co-workers at Beamline X8C, National Synchrotron Light Source, Brookhaven National Laboratory, and supported by the U.S. Department of Energy Basic Energy Sciences and a seed grant from the Wisconsin Energy Institute. The synthesis of the battery materials in Jin's lab was supported by National Science Foundation Division of Materials Research.  —Mark E. Griffin   http://news.wisc.edu/23687

Single Photonics and Quantum Information

 

Summary: The smallest unit of light is a “photon”. Generation, manipulation and measurement of light at or near the fundamental limit of a photon can enhance the performance of many optical systems. Remote sensing, long-distance communications, biological imaging, and quantum information science are some near-term applications that would benefit immensely from better optical components and techniques that work efficiently at few or single photon levels. However, the technologies to generate, manipulate, and detect these states of light are inadequate for the emerging applications. We are developing new light sources, detectors, and measurement techniques to address these needs. Description: One of the activities in this group is the development of single photon technologies for quantum information science and technology. We work closely with the Nanostructure Fabrication and Metrology Project on the generation of novel non-classical states of light and the detection of single photons. Currently, we are investigating the use of nonlinear fibers and nonlinear crystals as a source of correlated photon pairs or squeezed light. We are also manipulating the squeezed light to make Schroedinger "Cat" states of light. In addition to making non-classical states of light, we build detector systems that are the best in the world at operating at the single photon level. Presently, our project is primarily focused on using two different superconducting detector technologies -- transistion-edge sensors (TES) and superconducting nanowire single photon detectors (SNSPD). Using our sources and detectors, we also are actively involved in characterizing optical compoments at the few photon level, demonstrating new optical devices that function at the single photon level, demonstrating of new measurements at faint light levels, and demonstrating new applications that require single photons.   http://www.nist.gov/pml/div686/grp06/sspd.cfm

Heart attack Risk factors

 

By Mayo Clinic Staff Certain factors contribute to the unwanted buildup of fatty deposits (atherosclerosis) that narrows arteries throughout your body. You can improve or eliminate many of these risk factors to reduce your chances of having a first or subsequent heart attack. Heart attack risk factors include: Age. Men age 45 or older and women age 55 or older are more likely to have a heart attack than are younger men and women. Tobacco. Smoking and long-term exposure to secondhand smoke increase the risk of a heart attack. High blood pressure. Over time, high blood pressure can damage arteries that feed your heart by accelerating atherosclerosis. High blood pressure that occurs with obesity, smoking, high cholesterol or diabetes increases your risk even more. High blood cholesterol or triglyceride levels. A high level of low-density lipoprotein (LDL) cholesterol (the "bad" cholesterol) is most likely to narrow arteries. A high level of triglycerides, a type of blood fat related to your diet, also ups your risk of heart attack. However, a high level of high-density lipoprotein (HDL) cholesterol (the "good" cholesterol) lowers your risk of heart attack. Diabetes. Insulin, a hormone secreted by your pancreas, allows your body to use glucose, a form of sugar. Having diabetes — not producing enough insulin or not responding to insulin properly — causes your body's blood sugar levels to rise. Diabetes, especially uncontrolled, increases your risk of a heart attack. Family history of heart attack. If your siblings, parents or grandparents have had early heart attacks (by age 55 for male relatives and by age 65 for female relatives), you may be at increased risk. Lack of physical activity. An inactive lifestyle contributes to high blood cholesterol levels and obesity. People who get regular aerobic exercise have better cardiovascular fitness, which decreases their overall risk of heart attack. Exercise is also beneficial in lowering high blood pressure. Obesity. Obesity is associated with high blood cholesterol levels, high triglyceride levels, high blood pressure and diabetes. Losing just 10 percent of your body weight can lower this risk, however. Stress. You may respond to stress in ways that can increase your risk of a heart attack. Illegal drug use. Using stimulant drugs, such as cocaine or amphetamines, can trigger a spasm of your coronary arteries that can cause a heart attack. A history of preeclampsia. This condition causes high blood pressure during pregnancy and increases the lifetime risk of heart disease. A history of an autoimmune condition, such as rheumatoid arthritis or lupus. Conditions such as rheumatoid arthritis, lupus and other autoimmune conditions can increase your risk of having a heart attack.   http://www.mayoclinic.org/diseases-conditions/heart-attack/basics/risk-factors/con-20019520

Oct. 5, 1984, Launch of History-Making STS-41G Mission

 

A Florida dawn scene on Oct. 5, 1984 forms the backdrop for the climbing Space Shuttle Challenger, its two solid rocket boosters and external fuel tank, launched on the eight-day STS-41G mission. The scene was photographed by astronaut Paul J. Weitz, who was piloting the Shuttle training aircraft (STA). Crewed by Robert L. Crippen, Commander; Jon A. McBride, Pilot; Mission Specialists Kathryn D. Sullivan (now NOAA administrator), Sally K. Ride, David C. Leestma and Payload Specialists Marc Garneau of the Canadian Space Agency and Paul D. Scully-Power, the mission’s objectives included the deployment of the Earth Radiation Budget Satellite and the demonstration of the Orbital Refueling System by Sullivan and Leestma during a spacewalk. On this mission, Sullivan became the first U.S. woman to perform a spacewalk. Marc Garneau became the first Canadian astronaut to fly to space. The shuttle's crew of seven was the largest ever to fly on a single spacecraft at that time, and STS-41G was the first flight to include two female astronauts. STS-41G completed 132 orbits of the Earth in 197.5 hours, before landing at Kennedy Space Center, Florida, on Oct. 13. Image Credit: NASA Last Updated: Oct. 5, 2015 Editor: Sarah Loff http://www.nasa.gov/image-feature/oct-5-1984-launch-of-history-making-sts-41g-mission

Gorgeous calabash lamps transform any room into magical otherworldly realms

 

Why settle for a normal light when you can have one that transforms your room into a dazzling piece of art? Polish artist Przemek Krawczyński’s stunning sculptural lamps do just that, using tricks of the light to project magical shadow patterns onto walls. The Łódź-based artist handcrafts each unique lamp from dried calabash, or bottle gourds, that he intricately carves into shapes that create dazzling otherworldly atmospheres when illuminated at night.   Originally an engineer, Krawczyński started making calabash lamps after he came across the gourd fruit in 2009. The calabash is a vine grown for its gourd fruits that can be harvested when mature, dried, and used to make utensils, containers, and other products. Although there are many varieties of gourds that grow around the world, Krawczyński chooses to carve his lamps from the round African varieties. Related: Andrew Mowbray Grows Square Building Blocks from Living Gourds The beautiful calabash lamps are intricately handcrafted, from the initial sketches to the gourd processing and construction of the wood lamp base. “By day my lamp is a unique sculpture, while at night the light breathes new life into that sculpture, seeping through intricately carved wood and passing through thousands of holes,” says Krawczyński. “Flowing shadows fill the space and cast the patterns on the surrounding surfaces, which turns each interior into scene for breathtaking spectacle.” The unique lamps can take two to four months to complete, depending on the pattern and size. + Calabarte Via My Modern Met Images via Calabarte http://inhabitat.com/gorgeous-calabash-lamps-transform-any-room-into-magical-otherworldly-realms/

Review: Optoma NuForce BE6 Bluetooth earphones

 

The Optoma NuForce BE6 Bluetooth earphones are available now at a suggested retail price of US$129 (Credit: Paul Ridden/Gizmag) Optoma has today released the BE6 earphones, its fourth since acquiring the NuForce brand late last year, and its first wireless models. The stylish bullets are reported smaller than Bluetooth market leaders and are being aimed squarely at mobile music lovers with an ear for quality. Gizmag was sent a pre-release pair for review.   It really wasn't too long ago that those wanting to ditch the dangling cables to listen to music on the move had to make do with serious dips in sound quality, constant background hiss, and annoying pops and dropouts. As wireless technology improved and the default SBC codec started to get nudged out by more widespread adoption of aptX and AAC, so the annoying noise began to clear and the words quality and Bluetooth started to be uttered in the same breath. With the release of its new NuForce BE6 in-ear headphones, Optoma is promising to deliver the kind of audio quality over Bluetooth that was previously the exclusive domain of wired-for-sound audioholics. The BE6 earphones use a "state of the art" Bluetooth 4.0+EDR receiver, with support for both aptX and AAC audio technologies. This heady combination should result in top notch streaming sound quality from most modern source devices over a wireless range of up to 30 m (100 ft). Though touted as smaller than other leading wireless earphones, the Optoma NuForce BE6 in-ear headphones are still quite chunky monkeys. Each housing measures 27.2 mm (1.07 in) nose to tail (minus the silicone tip) and 13 mm (0.51 in) in diameter at its thickest stretch, and the whole shebang – both ear pieces, the cable, medium silicone tips and stabilizers – weighs just 17 g (0.6 oz). Within the cool and stylish machined aluminum housings are brand new 10 mm dynamic drivers, with 95 dB sensitivity, 20 ohm impedance and a frequency range of 20 Hz to 20 kHz. The inline remote hangs to the right, and is used to power on the BE6 earphones, put them into Bluetooth discovery mode, control playback, and take calls. It also facilitates communication with smartphone-based virtual assistants like Siri. Pairing was surprise-free and straightforward for all source devices tested, which included iOS and Android smart devices, laptops and computers. The only slightly awkward point being that discovery mode can only be activated from a powered off state, so you have to switch them off and on again with a long press of the power button before they're ready for pairing. The remote is also home to a microphone with -42 dB sensitivity and, though we found the audio on test calls over Skype via a laptop and on a smartphone to be received loud and clear, in both cases signal breakup, crackles and pops were reported at the other end. The remote contains a cylindrical 3.7 V/80 mAh Li-ion battery. Optoma claims up to 5.5 hours of up time between charges, though we found that continuous playback at comfortable volume levels yielded a little over 5 hours for every 2.5 hours on charge. The earphones will power off automatically after 3 minutes of inactivity. Two quick-fire beeps sound periodically during playback to announce that it might be a good idea to start looking for a wall outlet, but the LED can be consulted for a rough estimate of remaining battery life at any time by simultaneously pressing all three buttons. Two flashes indicate a low battery, three for 50 percent and four or five for full. If plugged in users have enabled voice prompts (by pressing the power and volume up buttons at the same time), battery life information will be delivered through the drivers in a human voice when the three buttons are pressed. Optoma says that the supplied proprietary silicone tips have been specifically designed for a more balanced and comfortable fit, though two pairs of (sweat- and moisture-resistant) Comply foam tips are also included for a more secure fit. On the subject of comfort and fit, I found the combination of shortened bud (custom designed with wider flare for optimum sound projection) and thick nozzle meant that I couldn't really push the earphones down into the ear canal like, say, with the T20 cabled in-ear headphones from RHA. This inevitably resulted in the BE6 earphones falling out mid-jog, but, more importantly, meant that the passive isolation from the sounds of the outside world was not particularly effective (which could arguably be a good thing for the safety of plugged in runners . And cyclists). Slotting a squishy stabilizer onto each housing helped keep the earphones in position. Optoma recommends a 45 degree from north orientation for each stabilizer, then plugging the BE6s in with a twist to lock in place. However, I found 70-75 degrees suited me better so would advise some positioning experimentation if the suggested fit doesn't work out. The rear of each earpiece is magnetic, so that the earphones can be snapped together around the neck when not in use. A small but useful detail, and quite a relief not to have buds bouncing around when bounding down the street toward the train station. The BE6 earphones are also reported splash-proof, meaning that they don't have to be quickly packed away if you're caught out by a quick shower while out on the morning run.   The high points, and the lows "NuForce is all about natural sound," Jon Gordem, Senior Director of Product Management, Optoma told us. "We want to be loyal to the source material and make sure we play audio in the way the artist intended it, regardless of the genre. This means that our sound signature needs to have explosive bass and crystalline highs all in full balance." So did the BE6 earphones live up to that ambitious "cord-less experience without compromising on sound quality" promise? Well, we found the audio to be as clean as a whistle, with no background hiss or detectable distortion, even at unhealthy volume levels. The in-ears proved pretty good all-round performers, offering lively reproduction across genres such as blues, pop, folk, jazz, classical and rock. We weren't presented with a huge soundstage, but it was by no means cramped. The sound signature treated all audible frequencies and instrumentation well, though in a similar fashion to the company's NE750M wired earphones, the mid-range was boosted slightly so that some guitar solos and vocals got a little more emphasis than expected. This can be a drawback for well-worn favorites, but can also be a bonus for quietly-spoken dialog in movies. While the NE750Ms offer a solid, though by no means booming, lower end performance, the BE6s do not. Personally, I'm not overly fond of bass-heavy tuning, steering clear of Beats-like thunder-punchers in favor of a flatter, neutral response. But I found the BE6 earphones to be a little too lacking in the bass department. It was certainly present in all the tunes listened to during the review, but the arresting thump on tracks like Ain't nothing wrong with that from Robert Randolph just wasn't there, Roger Waters was resigned to a backing member of Pink Floyd rather than a loud and proud key player and Three 6 Mafia didn't come even close to generating the familiar chest-filling warm glow. More bottom end could be brought in by tinkering with source hardware or software settings, of course, but in the interests of fairness and consistency, we opt for a flattened EQ in listening tests.   The bottom line The BE6 bullets were feather light to wear, but not the most comfortable in-ears we've ever plugged in. The flat cable is just over half a meter from cable relief to boxy relief (around 22 inches), a nice length. There was little physical noise when it was handled or it brushed against clothing while running, but taps and scrapes on the remote did cut through the tunes. The battery fell just short of the claimed 5.5 hours during review testing, managing over 5 hours of continuous playback – though you might get seven, eight or more hour long sessions at the gym before needing to break out the supplied USB cable and locate a power source. The wireless range of up to 30 m or so meant that the source player could be left on the patio table while wandering around the garden or in the kit bag when jumping from machine to machine at the gym. Streamed audio came through clean, clear and lively, let down only by a somewhat lackluster bass presence. The Optoma NuForce BE6 Bluetooth earphones are available from today at a suggested retail price of US$129. We were sent gray earphones for review, but they're also available in gold. Product page: Optoma NuForce BE6   http://www.gizmag.com/review-optoma-nuforce-be6-bluetooth-earphones/39709

Efficiency from larger perovskite solar cells improved

 

A new fabrication method enabled researchers to make larger perovskite cells with few defects, helping to maintain efficiency at larger cell sizes. Credit: Brown University / NREL Using a newly developed fabrication method, a research team has attained better than a 15-percent energy conversion efficiency from perovskite solar cells larger than one square centimeter area. The researchers, from Brown University and the National Renewable Energy Lab (NREL), have reported their findings in the journal Advanced Materials. Perovskites, materials with a particular crystalline structure, have caused quite a buzz in the solar energy world. Perovskite solar cells are relatively cheap to make, and the efficiency with which they can convert sunlight into electricity has been increasing rapidly in recent years. Researchers have reported efficiency in perovskite cells of higher than 20 percent, which rivals traditional silicon cells. Those high efficiency ratings, however, have been achieved using cells only a tenth of a square centimeter -- fine for lab testing, but too small to be used in a solar panel. "The use of tiny cells for efficiency testing has prompted some to question comparison of perovskite solar cells with other established photovoltaic technologies," said Nitin Padture, professor of engineering at Brown, director of Brown's Institute for Molecular and Nanoscale Innovation, and one of the senior authors of the new research. "But here we have shown that it is feasible to obtain 15-percent efficiency on cells larger than a square centimeter through improved processing. This is real progress." Maintaining high efficiency on larger perovskite cells has proved to be a challenge, Padture says. "The problem with perovskite has been that when you try to make larger films using traditional methods, you get defects in the film that decrease efficiency." The fabrication process that the Brown and NREL researchers reported in this latest paper builds on a previously reported method developed by Yuanyuan Zhou, a graduate student in Padture's lab. Perovskite precursors are dissolved in a solvent and coated onto a substrate. Then the substrate is bathed in a second solvent (called anti-solvent) that selectively grabs the precursor-solvent and whisks it away. What's left is an ultra-smooth film of perovskite crystals. In this new study Zhou and Mengjin Yang, a postdoctoral researcher at NREL, developed a trick to grow the perovskite crystals to a larger size. The trick is to add excess organic precursor that initially "glues" the small perovskite crystals and helps them merge into larger ones during a heat-treatment, which then bakes away the excess precursor. "The full coverage and uniformity over a large area come from the solvent method," Padture said. "Once we have that coverage, then we increase the size of the crystals. That gives us a film with fewer defects and higher efficiency." The 15-percent efficiency reached in this latest work is a good start, Padture said, but there's still room to improve. Ultimately, he would like to reach 20 to 25 percent in large-area cells, and he thinks that mark could be within reach using this method or a similar one. Padture and colleagues at the University of Nebraska-Lincoln were recently awarded a $4-million grant by the National Science Foundation to expand their perovskite research. Story Source: The above post is reprinted from materials provided by Brown University. Note: Materials may be edited for content and length. Journal Reference: Mengjin Yang, Yuanyuan Zhou, Yining Zeng, Chun-Sheng Jiang, Nitin P. Padture, Kai Zhu. Square-Centimeter Solution-Processed Planar CH3NH3PbI3Perovskite Solar Cells with Efficiency Exceeding 15%.Advanced Materials, 2015; DOI: 10.1002/adma.201502586   http://www.sciencedaily.com/releases/2015/10/151005132851.htm

Where to look for life? Astronomers devise 'habitability index' to guide future search

 

The James Webb Space Telescope, a large infrared telescope with a 6.5-meter primary mirror, is scheduled to be launched on an Ariane 5 rocket from French Guiana in October of 2018 and will be the premier NASA observatory of the next decade, serving thousands of astronomers around the world. UW astronomers have created a “habitability index for transiting planets” to help guide the ongoing search for life beyond Earth. Credit: NASA Powerful telescopes are coming soon. Where exactly shall we point them? Astronomers with the University of Washington's Virtual Planetary Laboratory have created a way to compare and rank exoplanets to help prioritize which of the thousands discovered warrant close inspection in the search for life beyond Earth. The new metric, called the "habitability index for transiting planets," is introduced in a paper accepted for publication in the Astrophysical Journal by UW astronomy professors Rory Barnes and Victoria Meadows, with research assistant and co-author Nicole Evans. "Basically, we've devised a way to take all the observational data that are available and develop a prioritization scheme," said Barnes, "so that as we move into a time when there are hundreds of targets available, we might be able to say, 'OK, that's the one we want to start with.'" The Kepler Space Telescope has enabled astronomers to detect thousands of exoplanets, those beyond our solar system -- far more than can be investigated one by one. The James Webb Space Telescope, set for launch in 2018, will be the first able to actually measure the atmospheric composition of a rocky, possibly Earthlike planet far off in space, and so vastly enhance the search for life. Astronomers detect some planets when the worlds "transit" or pass in front of their host star, thus blocking some of the light. The Transiting Exoplanet Survey Satellite, or TESS, is scheduled to launch in 2017 and will find many more worlds in this way. But it's the Webb telescope and its "transit transmission spectroscopy" that will really be able to study planets closely to hunt for life. But access to such telescopes is expensive and the work is methodical and time-consuming. The Virtual Planetary Laboratory's index is a tool to help fellow astronomers decide which worlds might have the better chance of hosting life, and so are worthy of focusing limited resources on. Traditionally, astronomers have focused the search by looking for planets in their star's "habitable zone" -- more informally called the "Goldilocks zone" -- which is the swath of space that's "just right" to allow an orbiting Earth-like planet to have liquid water on its surface, perhaps giving life a chance. But so far that has been just a sort of binary designation, indicating only whether a planet is, or is not, within that area considered right for life. "That was a great first step, but it doesn't make any distinctions within the habitable zone," Barnes said. "Now it's as if Goldilocks has hundreds of bowls of porridge to choose from." The new index is more nuanced, producing a continuum of values that astronomers can punch into a Virtual Planetary Laboratory Web form to arrive at the single-number habitability index, representing the probability that a planet can maintain liquid water at its surface. In creating the index, the researchers factored in estimates of a planet's rockiness, rocky planets being the more Earth-like. They also accounted for a phenomenon called "eccentricity-albedo degeneracy," which comments on a sort of balancing act between the a planet's albedo -- the energy reflected back to space from its surface -- and the circularity of its orbit, which affects how much energy it receives from its host star. The two counteract each other. The higher a planet's albedo, the more light and energy are reflected off to space, leaving less at the surface to warm the world and aid possible life. But the more noncircular or eccentric a planet's orbit, the more intense is the energy it gets when passing close to its star in its elliptic journey. A life-friendly energy equilibrium for a planet near the inner edge of the habitable zone -- in danger of being too hot for life -- Barnes said, would be a higher albedo, to cool the world by reflecting some of that heat into space. Conversely, a planet near the cool outer edge of the habitable zone would perhaps need a higher level of orbital eccentricity to provide the energy needed for life. Barnes, Meadows and Evans ranked in this way planets so far found by the Kepler Space Telescope, in its original mission as well as its "K2" follow-up mission. They found that the best candidates for habitability and life are those planets that get about 60 percent to 90 percent of the solar radiation that the Earth receives from the sun, which is in keeping with current thinking about a star's habitable zone. The research is part of the ongoing work of the Virtual Planetary Laboratory to study faraway planets in the ongoing search for life, and was funded by the NASA Astrobiology Institute. "This innovative step allows us to move beyond the two-dimensional habitable zone concept to generate a flexible framework for prioritization that can include multiple observable characteristics and factors that affect planetary habitability," Meadows said. "The power of the habitability index will grow as we learn more about exoplanets from both observations and theory." Story Source: The above post is reprinted from materials provided by University of Washington. The original item was written by Peter Kelley. Note: Materials may be edited for content and length. Journal Reference: Rory Barnes, Victoria S. Meadows, Nicole Evans. Comparative Habitability of Transiting Exoplanets. Astrophysical Journal, 2015 [link]   http://www.sciencedaily.com/releases/2015/10/151005184638.htm