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Knots are all around us: in computer cables, headphones and wires. But, although they can be a nuisance, they’re also very useful when it comes to tying up your laces or when you go sailing. In maths, there are no less than six billion different potential knots, but what about knots in chemistry? Since the 1970s, scientists have been trying to knot molecules together to create new, custom-made mechanical properties, which will give rise to new materials. The first successes took place twenty years later but the process remains laborious. Today, researchers from the University of Geneva (UNIGE), Switzerland, have developed a simple and effective technique for tying knots in molecules, and have for the first time observed the changes in properties that result from these interlockings. The results, which you can read about in the journal Chemistry — A European Journal, open up new perspectives for designing materials and transferring information molecularly.
Knots are certainly useful. But what about in chemistry? Is it possible to tie molecules together? The idea first made an appearance in 1971 with the aim of creating new materials induced by the changes in mechanical and physical properties that would result from these interlockings. But it was not until 1989 that Jean-Pierre Sauvage, the French 2016 Nobel Prize winner in chemistry, succeeded. Scientists have subsequently worked hard at trying to form knots but it remains challenging: “To tie molecules together, you have to use metals that attach to the molecules and direct them on a very specific path forming the intersections that are needed to make knots,” explains Fabien Cougnon, a researcher in the Organic Chemistry Department in UNIGE’s Faculty of Sciences. “But it is a complex process that often results in a loss of raw material of over 90%! The resulting amount of molecular knots is typically only a few milligrams at most, not enough to make new materials.”
Hydrophobic molecules that tie together on their own
The UNIGE chemists developed a new technique that makes it possible to create interlocked molecules easily. “We use fatty molecules that we soak in water heated to 70 degrees. Since they are hydrophobic, they try to escape the water at all costs, gathering together and forming a knot by means of self-assembly,” says Tatu Kumpulainen, a researcher in the Physical Chemistry Department in UNIGE’s Faculty of Sciences.
Thanks to this new technique, the Geneva-based chemists can make molecular knots effortlessly, and — even more importantly — without losing any material. “We transform up to 90% of the basic reagents into knots, which means we can consider a real analysis of the changes in the mechanical properties induced by the knots, which has never been done before!” notes Cougnon. Although they cannot choose how the molecules are knotted together, they are able to reproduce the same knot at will, because the same chemical structure will always form an identical knot in aqueous environment.
Each knot has its own mechanical properties
Now that knotting molecules has become easy, what can we do with these knots? Is there any value in forming them? To check the impact of the interlockings, the Geneva chemists chose a family of molecules that all have the same design: they absorb ultraviolet, are fluorescent and are highly sensitive to the general environment, especially the presence of water. “We created four knots, from the simplest to the most complex (0, 2, 3 and 4 intersections), which we compared to a reference molecule which constitutes their basis,” explains Cougnon. “To do this, we first used nuclear magnetic resonance (NMR) to observe the stiffness of the different parts of the knots and the speed and way they move relative to one another.” The scientists found a first change in mechanical properties: the more complex the knots are, the less they move.
The chemists subsequently used spectroscopy to compare the spectra of the four knots with each other. “We soon noticed that the looser single knots (0 and 2 intersections) behaved in the same way as the reference molecule,” continues Kumpulainen. “But when the knots are more complex, the molecules — which were tighter — changed their physical properties and colour! Their way of absorbing and emitting light differed from the reference molecule.” This change in colour means that the scientists can visualise the mechanical properties specific to each assembly, whether it is its elasticity, structure, movement or position.
For the first time, the Geneva chemists have shown that knotted molecules change mechanical properties. “We now want to be able to control these changes from A to Z so that we can use these knots, for example, as indicators for the properties of the environment,” says Kumpulainen. They also plan to build new materials, such as elastics, using the networks of knots now that there is no loss of material when making the intersections. “At last, we can consider transferring information inside a knot thanks to a simple change of position on a part of the knot which would be reflected throughout the structure and would convey the information,” concludes Cougnon.
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Processing images to allow self-driving cars to see where they’re going could get easier thanks to a specially sculpted lens that does the work of a computer.
Dutch and American researchers say they can use a metasurface to passively detect the edges of objects in video. Computers can perform such edge detection for autonomous vehicles or virtual reality applications, but that uses power and is not instantaneous. “If you want to do that digitally, it takes time for the computer to compute,” says Albert Polman, who heads the Light Management in New Photovoltaic Materials group at AMOLF, a scientific research institute in Amsterdam, the Netherlands.
In a paper in Nano Letters, Polman and colleagues describe how their material performs the mathematical operations necessary for edge detection. They built a metasurface, which is studded with tiny pillars, smaller than the wavelength of light, which can manipulate light in unusual ways based on their size and arrangement. In this case, they started with a thin sheet of sapphire, less than half a millimeter thick, and added pillars of silicon that were 206 nm thick, 142 nm tall, and spaced 300 nm apart.
When placed on the surface of a standard CCD chip, the metasurface acts like a lens, passing light that strikes it at steep angles but filtering out light hitting it at very slight angles. The features of an image are built from combinations of different light waves, and the waves that get filtered out carry the fine details of the image, leaving only the sharper components, such as the edges of a person’s face compared to the whiteboard behind her.
Depending on the computer and the size of the image, it might take several milliseconds to process this information digitally. With the analog approach, only limiting factor is the thickness of the metasurface. “It’s just the time light takes to travel 150 nm, which is basically nothing,” Polman says.
It’s also a passive technique. “It’s just a piece of glass, so you don’t need to give it power,” he says. Of course, the digital camera and a computer would still have a role, but Polman says this hybrid approach should be more efficient.
The researchers would like to try other materials, such as titanium oxide or silicon nitride, to see if they can get even better results. And while this metasurface captures edges in one dimension, they’d like to try two-dimensional designs, so they can capture edges at different orientations.
New batteries are often described with comparatives: they’re safer, lighter, or longer-lived than today’s versions. Solid-state batteries—those which contain no liquid—can make two such claims. With inorganic electrolytes, they’re much less likely to catch fire than traditional lithium-ion batteries, which have organic electrolytes. And by swapping out graphite for lithium as the anode, you can get a massive increase (up to 10-fold) in energy density, making solid-state batteries look especially promising for electric vehicles.
“That’s the Holy Grail. Lithium metal has the highest gravimetric density of all materials,” says Adam Best, who’s in charge of battery research at the Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia’s national science agency.
But a major snag remains in bringing solid-state batteries to market—how to manufacture electrolytes that are strong and durable, yet thin enough to be good ion conductors. Ideally, these electrolytes should be tens of microns thick, similar to the separators in today’s lithium-ion batteries, says materials scientist Ping Liu from the University of California, San Diego. “But because most solid electrolytes are ceramic, when you make a thin layer, they’re inherently brittle,” he says.
For developers planning to incorporate route optimization in applications they’re creating, it’s helpful to know the top tips for choosing a routing API. When developers integrate the right routing API, they provide critical functionality for their application. However, choosing the wrong routing API can result in limited functionality and unforeseen costs. Here are the top six tips for choosing a routing API from the team at
The RouteSavvy Route Optimization API is a powerful, affordable API that helps developers incorporate route optimization into software solutions they’re developing.
Floral Business Software Company Uses the RouteSavvy API to Help Florists Improve Operations
When you’re in the business of delivering perishable goods like flowers, every minute counts – not only to deliver a fresh product but to deliver those goods as efficiently and cost-effectively as possible. MAS Direct is an information technology company that specializes in software to help florists of all sizes manage their businesses – from order entry to delivery to back-office accounting and collections.
MAS Direct uses OnTerra Systems’ RouteSavvy route optimization API to integrate route optimization into their software. By incorporating the RouteSavvy API into their floral business operations software, florists using the MAS software can more efficiently route their flower deliveries while saving money on fuel costs and overtime labor.
“MAS Direct provides technology for retail and wholesale flower shops. Efficient routing of flower deliveries is a huge factor for our customer’s businesses, especially in larger cities,” said Chris Golden, a software developer for MAS Direct.
Mr. Golden adds that he chose the RouteSavvy route optimization API after researching its features and cost. “RouteSavvy offered the route optimization features we needed, and at a significantly lower price than other similar products,” he said. The RouteSavvy Route Optimization API starts at just $500 per year. Other route optimization APIs cost between $3,000 and $5,000,” according to Mr. Golden.
“Thanks to the RouteSavvy Route Optimization API, we’ve seen our florist customers achieve 10-20% increases in efficiency.” – Chris Golden, Software Developer, MAS Direct
MAS Direct used the RouteSavvy Route Optimization API to quickly and easily incorporate route optimization into their software. “The RouteSavvy Route Optimization API allows our customers to make more deliveries per day, and saves both time and fuel. By using RouteSavvy route optimization, we’ve seen 10-20% increases in efficiency for our florist customers,” said Mr. Golden.
Once the MAS Software has organized the day’s flower deliveries, the addresses are sent to the RouteSavvy route optimization application within their software. RouteSavvy creates the most efficient route, which is then stored, printed out, and ported to the floral delivery driver’s iPad or iPhone.
RouteSavvy’s positive effect on their florist customers has been huge, according to Chris Golden. “Being able to optimize delivery routes means you’re on the road less. This saves on fuel costs, makes customers happy, and allows florist employees to spend more time in the shop, rather than on the road.”
Another area where the RouteSavvy Route Optimization API helps MAS Direct’s customers save money is in overtime labor. If drivers have to work longer than eight hours to finish their flower deliveries, they’re paid overtime. When RouteSavvy route optimization is used, it can help drivers finish their deliveries within an eight-hour window, saving florist shops overtime labor costs.
Chris Golden says the RouteSavvy Route Optimization API from OnTerra Systems is helping their customers save time, save on fuel costs, and increase productivity. For any business or industry where margins are tight, the RouteSavvy Route Optimization API can make a significant contribution to improving the bottom line.
For more information, visit the OnTerra Systems USA Corporate Website: www.onterrasystems.com
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Author: <a href="https://www.programmableweb.com/user/%5Buid%5D">smilroy</a>
Snakes are incredible creatures, in that while they lack legs, they’re still able to get around quite well using an oscillating motion. While we’ve yet to entirely replicate their smooth natural movements, this servo-driven snake by YouTuber Nevon Projects is a valiant attempt.
The snake-bot employs a total of 12 servos to twist its body as needed, producing forward motion with the help of rollers below. As seen in the video at around 1:45, it can even twist itself into a square-ish pattern, and presumably any other shape that one could conceive. The device is capable of slithering across smooth surfaces with ease, traversing rougher terrain, and even oscillating over wet floors.
Servos are powered by a 7.4V battery pack, while a separate supply feeds the Arduino Mega that’s used for control. The user interface consists of a smartphone via the robot’s onboard Bluetooth module and a WiFi camera provides feedback for first-person snake action. A distance sensor is also implemented on a small servo that swivels about, allowing it to navigate around on its own if you so desire.
One interesting feature is that the batteries and forward sensor are arranged on a sort of head assembly, while a similar tail section mounts electronics including the Arduino. Both are linked together over the body with quite a bit of wire.
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Author: Jeremy S. Cook
The vast majority of ground vehicles utilize wheels for a reason: they’re extremely efficient over flat ground. One of the best examples of that principle is the humble bicycle. The average person can travel on a bicycle many times further — and faster — than they could while running or walking. Skateboards aren’t quite as efficient, but they do have the benefit of being lightweight and portable. Josh Geating and his team are trying to improve on typical electric skateboards to build the “most agile, rideable flatground wheeled vehicle in the world.”
A key word in that quote is “agile.” That means speed in a straight line isn’t the primary goal of this project. Instead, Geating’s team is try to build a skateboard-style vehicle that can maneuver better than any other. Power and speed are certainly a factor, but the ability to turn on a dime is just as important. To make it happen, they’ve designed three prototypes so far. All of them are using massive 80mm brushless DC motors that are controlled by an Arduino Due board through VESCs (Vedder Electronic Speed Controllers). Those motor controllers have additional features when compared to a conventional ESC, including regenerative braking.
The first of the prototypes was designed with omniwheels in order to facilitate extremely tight turns. Unfortunately, those wheels are normally intended for slow speed robots and were quickly torn to shreds by the power from the large motors. The following two designs utilized swerve drives and hard wheels, which allow each wheel to be turned and powered independently. The first of those had three wheels, but ended up being unwieldy. The second of those had four wheels and fared better, but still didn’t perform at the level they’re hoping for.
The Kinetik project is, however, still underway. Be sure to follow along with their build logs as they continue to push towards their goal.
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Author: Cameron Coward
Raspberry Pi is every maker’s go-to single-board computer (SBC), and they’re useful for a wide range of projects. You can use a Raspberry Pi in everything from robots to IoT (Internet of Things) controllers. But it is still a fully-functional computer that you can use like any other computer. With just a few upgrades, a Raspberry Pi is great as a dedicated audio system computer. That’s exactly what redditor Sanfran54 has done with their custom audio system housed in a cigar box.
This project started with Sanfran54 receiving a Raspberry Pi starter kit as a gift from their son a few years ago. They had been listening to music by simply plugging headphones into their laptop, but decided that the Raspberry Pi would be ideal for a dedicated music player. The Raspberry Pi 3 Model B that Sanfran54 has is perfect for running audio software — Audacious in this case — but it does lack an onboard sound card. Cheap USB options are available, but Sanfran54 wanted something higher quality.
To achieve that, they used a HiFiBerry DAC (Digital-to-Analog Converter). That takes the music bits directly from the Raspberry Pi and turns them into a high-quality analog audio signal. That, in turn, is fed to a Bravo V2 hybrid tube amplifier. Finally, AKG 240 studio headphones are plugged into the amplifier’s output. A 5″ touchscreen LCD display from Adafruit is used for navigating the software, with a separate wireless Bluetooth keyboard available for when typing is necessary. The Raspberry Pi, along with a hefty power supply, are housed within a classy cigar box, with the LCD screen and amplifier mounted to the top of the box. The result looks good, is convenient, and produces high-fidelity sound.
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Author: Cameron Coward
Whether they’re aiming to avoid high financial management fees, control their own investments, or enjoy the thrill of playing the market, more consumers are opening investment accounts and making their own stock picks.
But a new study from the UBC Sauder School of Business has found that less experienced investors are failing to diversify — and could be putting themselves at serious financial risk. The effect is so pronounced that many amateur investors would be better off choosing stocks at complete random.
For the study, researchers first asked participants to create portfolios of financial assets using tables of previous returns, and then assessed the participants’ level of financial literacy. The researchers found the investors with poor financial literacy tended to choose positively correlated assets — for example, stocks in oil companies and forestry — which tend to fluctuate in value together.
“An amateur investor might buy stocks in lumber, mining, oil and banks, and believe they are diversifying because they’re investing in different companies and sectors,” said David Hardisty, study co-author and assistant professor at UBC Sauder. “But because all of those equities tend to move in unison, it can be quite risky, because all the assets can potentially plunge at the same time.”
More experienced investors know to hedge their bets by including negatively correlated assets, which are likely to move down when others go up — or uncorrelated assets (ones that move up and down independently of the others) in order to mitigate losses.
The researchers also found that the amateur investors were actively preferring correlated assets because they seemed less complicated and more predictable.
“If it seems predictable, it seems safer and easier to track,” explains Hardisty. “Whereas if you have a combination of assets that all go in different directions, it seems chaotic, unpredictable and riskier.”
Ironically, when the study participants were encouraged to take more risk when creating a portfolio, the amateur investors ended up making safer, more diversified selections, compared to when they were encouraged to avoid risk.
“This shows that amateur investors rely on a definition of risk that greatly differs from the objective definition of portfolio risk,” said Yann Cornil, assistant professor at UBC Sauder and co-author of the study. “This can lead them to make objectively low-risk investments when they intend to take risk, or to make high-risk investments when they intend to reduce risk.”
The researchers found that when amateur investors are shown the aggregate returns of portfolios (and not merely the returns of each asset composing the portfolio), they can see that having negatively correlated or uncorrelated assets is the winning investment strategy — even if it might seem counterintuitive to play both sides.
“If you don’t diversify, when one asset does well the other ones are also going to do well. But if one does badly it’s likely the others will all do badly — and in investing, you want to avoid those worst-case scenarios,” says Hardisty, who hopes the research will encourage investors to educate themselves on investment strategies, and use the diversification tools that online investment services provide to properly balance their portfolios.
“In the best-case scenario you could make lots of money and have an extra vacation or buy a car or something like that,” he explains of the positively correlated accounts. “But if your whole portfolio crashes you could risk losing your life savings. So, the best-case scenario isn’t that much better, but the worst-case scenario is a whole lot worse.”
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A large portion of you are probably wearing a fitness tracker right now as you read this. They’re a great way to collect data on your physical activity and ensure that you’re getting regular exercise. But while basic fitness trackers are very affordable, you’re almost always stuck with proprietary hardware and software. That usually means you’re using an app you have no control over, and which could even be harvesting your data. That’s why the open source OpenHAK was developed, and now it’s launching on Kickstarter.
OpenHAK is, at first glance, just a very simple fitness tracker. The basic model is just a bare PCB and a wrist band, and doesn’t even have a display. But the beauty of the OpenHAK is in how it can be modified. All of the design files and code are available, so you can customize it however you want. That also applies to the OpenHAK’s app, so you can be sure that your data and privacy are protected. At launch, there are already options to add a display or vibration motor, and the community is likely to develop more add-ons in the future.
OpenHAK is built around a Simblee BLE (Bluetooth Low Energy) module, which is no longer being produced. Luckily, the OpenHAK team purchased a large quantity of the modules a couple of years ago. The other major components include a Bosh BMI160 step counter and a Maxim MAX30101 heart rate sensor. Those are broken out through the PCB, and there are available pins to add on additional hardware. The OpenHAK has already been tested as a badge, so supply and manufacturing shouldn’t be an issue.
If you want an OpenHAK fitness tracker, the Kickstarter campaign will be running until September 6th. A single OpenHAK, with a 3D-printed case, battery, and watchband, costs $100. Rewards are expected to be delivered in December.
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Author: Cameron Coward