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October 10 2019

How Random is Random?

Many languages feature a random number generator library for help with tasks like rolling a die or flipping a coin. Why, you may ask, is this necessary when humans are perfectly capable of randomly coming up with values?

[ex-punctis] was curious about the same quandary and decided to code up an experiment to test the true randomness of human. A script guesses the user’s next input from two choices, keeping a tally in the JavaScript backend that holds on to the past five choices. If the script guesses correctly, they take $1 from the user. Otherwise, the user earns $1.05.

The data from gathered from running the script with 200 pseudo-random inputs 100,000 times resulted in a distribution of correct guess approximately normal (µ=50% and σ=3.5%). The probability of the script correctly guessing the user’s input is >57% from calculating µ+2σ. The result? Humans aren’t so good at being random after all.

It’s almost intuitive why this happens. Finger presses tend to repeat certain patterns. The script already has a database of all possible combinations of five presses, with a counter for each combination. Every time a key is pressed, the latest five presses is updated and the counter increases for whichever combination of five presses this falls under. Based on this data, the script is able to make a prediction about the user’s next press.

In a follow-up statistic analysis, [ex-punctis] notes that with more key presses, the accuracy of the script tended to increase, with the exception of 1000+ key presses. The latter was thought to be due to the use of a psuedo random number generator to achieve such high levels of engagement with the script.

Some additional tests were done to see if holding shorter or longer sequences in memory would account for more accurate predictions. While shorter sequences should theoretically work, the risk of players keeping a tally of their own presses made it more likely for the longer sequences to reduce bias.

There’s a lot of literature on behavioral models and framing effects for similar games if you’re interested in implementing your own experiments and tricking your friends into giving you some cash.

Turning Old Toggle Switches Into Retro-Tech Showpieces

While those of us in the hacking community usually focus on making new things, there’s plenty to be said for restoring old stuff. Finding a piece of hardware and making it look and work like new can be immensely satisfying, and dozens of YouTube channels and blogs exist merely to feed the need for more restoration content.

The aptly named [Switch and Lever] has been riding the retro wave for a while, and his video on restoring and repairing vintage toggle switches shows that he has picked up a trick or two worth sharing. The switches are all flea market finds, chunky beasts that have all seen better days. But old parts were built to last, and they proved sturdy enough to withstand the first step in any restoration: disassembly. Most of the switches were easily pried open, but a couple needed rivets drilled out first. The ensuing cleaning and polishing steps were pretty basic, although we liked the tips about the micromesh abrasives and the polishing compound. Another great tip was using phenolic resin PCBs as repair material for broken Bakelite bodies; they’re chemically similar, and while they may not match the original exactly, they make for a great repair when teamed up with CA glue and baking soda as a filler.

3D-printed repairs would work too, but there’s something satisfying about keeping things historically consistent. Celebrating engineering history is really what restorations like these are all about, after all. And even if you’re building something new, you can make it look retro cool with these acid-etched brass plaques that [Switch and Lever] also makes.

Modular Music Synthesis On The Web

It is hard to imagine how the electronics hobby survived without the Internet. You found like-minded people and projects in magazines. And it is even harder to imagine what projects were in the magazines before the widespread availability of CPU chips. Think about it, there are only so many things you can build with a handful of tubes, transistors, and small ICs. But before the computer revolution took over the hobby, there were always a lot of articles about music synthesis. Coming full circle, you can now build a virtual synthesizer on the web using Zupiter, a modular synthesizer that runs in your browser.

That link is actually about Zupiter, but you can go straight to it if you just want to play. However, we had to do a little reading and try some of the examples, too. You can see a video about the synthesizer, below.

The term modular refers to a type of synthesizer that had different modules that come together by means of patch cables to create a particular sound. This type of synthesizer appeared around 1963, being independently developed by both Moog and Buchla working from innovations from Hugh Le Caine.

Of course, not everything you can do with Zupiter sounds like music. We were partial to this example. If you prefer real hardware, grab a Game Boy. What goes well with a modular synthesizer? How about a modular keyboard?

 

October 09 2019

Literal Stretch-Sensing Glove Reconstructs your Hand Poses

Our hands are rich forms of gestural expression, but capturing these expressions without hindering the hand itself is no easy task–even in today’s world of virtual reality hardware. Fret not, though, as researchers at the Interactive Geometry Lab have recently developed a glove that’s both comfortable and straightforward to fabricate while capturing not simply gestures but entire hand poses.

Like many hand-recognition gloves, this “stretch-sensing soft glove” mounts the sensors directly into the glove such that movements can be captured while hands are out of plain sight. However, unlike other gloves, sensors are custom-made from two stretchable conductive layers sandwiched between a plain layer of silicone. The result is a grid of 44 capacitive stretch sensors. The team feeds this datastream into a neural network for gesture processing, and the result is a system capable of reconstructing hand poses at 60Hz refresh rates.

In their paper [PDF], the research team details a process of making the glove with a conventional CO2 laser cutter. They first cast a conductive silicone layer onto a conventional sheet of silicone. Then, with two samples, they selectively etch away the conductive layer with the unique capacitive grid images. Finally, they sandwich these layers together with an additional insulating and glue it into a hand-shaped textile pattern. The resulting process is a classy use of the laser cutter for the design of flexible capacitive circuits without any further specialized hardware processes.

While we’re no stranger to retrofitting gloves with sensors or etching unconventional materials, the fidelity of this research project is in a class of its own. We can’t wait to see folks extend this technique into other wearable stretch sensors. For a deeper dive into the glove’s capabilities, have a look at the video after the break.

Connected World Contest: Four Top Winners Announced

We love seeing the astonishing array of projects large and small entered into Hackaday contests which push the boundaries of what is possible. Our latest has been the Connected World contest which was announced back in June, and today we’re pleased to bring you its four top winners. As a recap, the brief was to create something that connects wirelessly and shows a blend of creativity and functionality. The final four have a diverse range of applications, and here they are with their respective categories:

Best Project:  Hive Tracker

The Hive Tracker sensor head The Hive Tracker sensor head

Watchers of the gaming hardware scene may be familiar with the HTC Vive Tracker virtual reality position feedback system in which an infra-red laser scans a scene and is picked up by a handheld device to measure its position at a milimetric level. HiveTracker takes the Vive Tracker’s sensor and miniaturises it, with a central board containing a Nordic NRF52 RF-enabled microcontroller, and four satellite boards containing Triad TS4231 laser tracking chips.

The original intention was to use an FPGA for the processing, but clever use of a peripheral interface mode on the Nordic chip allowed them to dispense with it.

Best Design: Fossasat Open Source Satellite

FossaSat-1, with solar panels deployed. FossaSat-1, with solar panels deployed.

Think for a moment to the most ambitious project you might attempt… it’s possible that you couldn’t set your sights higher than space. That’s what the Fossa Systems team from Spain have done with FossaSat-1, an open-source pocketqube picosatellite that is to be launched with its total budget for both development and launch to be only 30,000 Euros. Like many of these tiny satellite designs it will be constructed from FR4 PCB material, and features both an ATmega328AU processor and a LoRa radio. It has a set of solar panels that are concealed within its 50mm-sided cube at launch, but will fold out to give it extra power in flight. Its payload will be student projects using an ATmega1284 processor.

Best Documentation: Domsnif Dot Matrix

The Domsnif prototype board. The Domsnif prototype board.

Many devices now contain a microprocessor, but do their job without any computer interface at all. Extracting their data can present a near-impossible challenge requiring complete reverse engineering. There is often something of a backdoor which can be used to circumvent the need for such work, and it comes in the form of the device’s LCD display.

Since many of these devices use known protocols it can become a relatively straightforward task to read the data being sent to them if you can gain access to their interface connector. This is the approach taken by DoMSnif, which hooks up to an LCD interface, decodes its signals, and offers the data to the wider world over a Bluetooth connection. As it stands in prototype form it uses a Teensy to retrieve the data and a Feather to handle both Bluetooth and USB, but the next plan is to use a 5V Cortex M0+ chip from Microchip in those roles.

Best Social: Telepresent Heart

The Telepresent Heart mechanisam can clearly be seen in this series of views. The Telepresent Heart mechanism can clearly be seen in this series of views.

Being apart from the love of your life is rough, especially when it is for an extended time. Telepresent Heart from [Claire Puginier]  aims to bring pining couples a little closer together by means of a pair of heart sensing pendants that each pulsate to the heartbeat of the other. It works with a sensor and servo-driven heartbeat mechanism, coupled vial Bluetooth to a smartphone app. The partners pair their smartphone apps, and each feels the heartbeat of the other. We really like this as a truly novel idea, and we look forward to seeing it realised as a working pair of devices.

Of course, these four winners are just a tiny fraction of the total entry, and indeed they aren’t even all of the winners, either. There are 30 other uncategorised winners listed on the contest page which contain some real gems, as well as the rest of the entries which can be found in the competition entry list. Thanks very much to all who took part, and we look forward to the next Hackaday contest.

These Dice Know If You’re Cheating

Fans of D&D are surely aware of the significance of a good pair of dice. What if your dice were not only stylish, but smart? For anyone who’s ever had to deal with playing board games with less than reputable siblings or friends, the electric die just might be your savior.

The dice are configured via Bluetooth, tracking rolls and stats over the course of gameplay captured by an accelerometer.

The PCB had to have a flexible surface – specifically in the shape of an unfolded icosahedron – in order to form the shape of the die which constrains the design to two layers. Each face contains an LED facing outwards to light up the number on that side. The LEDs are directly powered by a rechargeable battery, which uses a small coil for wireless inductive charging. Rather than opting for a Qi charger chipset, which regulates the maximum amount of power transmitted if the efficiency falls below a threshold, [Jean Simonet] uses a simpler charger setup using a full bridge rectifier, capacitors, and a linear regulator to create a stable 5V supply for the receiving end.

While the initial design for the die required an injection molded plastic shell, an easier solution was to simply cast the designs in resin. The electronics are placed into a dice mold and cast just as a regular die would be.

This luckily also solved the issue of needing to fit the components inside a screw-on container with a removable lid, which presented a hassle in terms of finding a battery that would fit the dimensions. The LEDs – purchased for cheap on Alibaba – are daisy chained to reduce the complexity of the routing.

One issue with the LEDs, however, is that the internal PWMs modulating the intensity remain on even at an intensity of 0, constantly drawing 21 mA (for the 21 LEDs on the die). This causes the battery to die after 2-3 hours. The solution [Simonet] used was to add a transistor to cut off power to the LEDs and to have the MCU toggle the transistor when the LEDs are turned off. Even this solution didn’t solve the entire problem since the LEDs still drain current from the data and clock lines, so those lines had to be low before going to sleep.

There were some stability issues with using a small buck converter to bring the LiPo voltage down to 3.3V, so the power regulation was done directly by the MCU instead. Switching the die off is controlled by a magnetic switch connected to a power buck converter that turns off logic when a magnet is present. This initially caused the LED control lines to become floating when power was turned off, turning the LEDs to arbitrary colors. The solution was to wire the output of the magnetic sensor to the MCU and to allow the software to handle the LEDs as well.

Maybe it’s because creator [Simonet] happens to be a game developer as well, but the early development stages of the electronic die (CAD, circuit schematics, prototyping, hand soldering components) were streamed on Twitch, adding some interactivity to even the build phase. The end result may be small, but these dice certainly have large brains!

The HackadayPrize2019 is Sponsored by:

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Willem Kolff’s Artificial Organs

In my youth I worked for a paid ambulance service, and while we all lived for the emergency calls, the routine transports were the calls that paid the bills. Compared with the glamor and excitement of a lights-and-siren run to a car wreck or heart attack, transports were dull as dirt. And dullest of all were the daily runs from nursing homes to the dialysis center, where rows of comfy chairs sat, each before a refrigerator-sized machine designed to filter the blood of a patient in renal failure, giving them another few days of life.

Sadly, most of those patients were doomed; many were in need of a kidney transplant for which there was no suitable donor, while some were simply not candidates for transplantation. Dialysis was literally all that stood between them and a slow, painful death, and I could see that at least some of them were cheered by the sight of the waiting dialysis machine. The principles of how the kidneys work have been known since at least the 1800s, but it would take until 1945 for the efforts of a Dutch doctor, using used car parts and sausage casings, to make the predecessor of those machines: the first artificial kidney.

Restoring Balance

Schematic of a nephron, the functional unit of the kidney. Source: Madhero88 [CC BY 3.0], via Wikimedia CommonsThe kidneys are fascinating organs, perfectly adapted to their primary role of filtering metabolic waste products from the blood. Proteins and nucleic acids are nitrogen-rich, and when either is broken down in the body, urea and uric acid are produced. Those nitrogenous waste products are toxic above a certain concentration; the kidneys do the job of filtering out the waste, diluting it with water, and excreting it as urine.

We’ve all likely seen the principle behind this demonstrated at some point in school. Osmosis is the tendency of solutions to seek a balance between solvent and solute across semipermeable membranes such as biological tissues. In the kidney, blood plasma (the solvent) containing nitrogenous waste (the solute) flows through capillaries (the semipermeable membrane). The other side of the membrane is a structure called the Bowman’s capsule, into which flows the nitrogenous waste along with a fair amount of sodium chloride, glucose, and amino acids. Most of the water and some of the solutes in that filtrate are reabsorbed by capillaries further along the Bowman’s capsule, with the balance excreted as urine.

Healthy kidneys are a marvel of efficiency, filtering the entire volume of plasma in the body 60 times a day. Of the 180 liters of the bulk filtrate produced almost all of it is reabsorbed, leaving behind about 2 liters of urine to be eliminated. Without the kidneys, the body would be unable to maintain fluid balance, blood pH, and the correct concentrations of vital electrolytes. Nausea, vomiting, and edema would follow quickly; the inevitable death would be slow and gruesome, as a young Dr. Willem Kolff would learn first hand.

No Way to Die

Dr. Kolff and his wife Janke in Nazi-occupied Kampen, 1941.

In 1938, a 22-year-old man entered the hospital at the University of Groningen in the Netherlands in acute renal failure. Dr. Kolff, fresh out of medical school and barely older than his patient, was put in charge of the case. There really wasn’t much to do; while Dr. Kolff knew exactly what was happening – up to 20 grams of urea were accumulating in the man’s body every day, slowly poisoning him – there was no way to remove it. Dr. Kolff could do little but watch helplessly as the man died.

Keen to find a way to save such patients, Dr. Kolff began looking for ways to “jump start” the kidneys. For several years he looked for drugs to stimulate the kidneys to improve their function, but found none. Then history took an unexpected turn and the world went to war. When the Germans swept through the Netherlands, Dr. Kolff happened to be in The Hague. As Nazi bombers swarmed overhead, he went to the hospital and volunteered to set up a blood bank. After four days of scrounging equipment and supplies and dodging Nazi snipers, the hospital’s first blood bank was in operation. It remains in operation to this day.

To avoid the worst of the Nazi occupation, he left the university hospital and headed for Kampen, a smaller city. The hospital there was glad for the help and paid the young internist enough to start working on his kidney treatments again. This time, he would concentrate on an artificial kidney.

Dr. Kolff had done experiments with cellophane sausage casings. He filled them with blood that had been spiked with urea and placed them in a saline solution. After some time and agitation, the urea had moved across the semipermeable cellophane membrane into the salt bath, removing it from the blood inside. He had the basis for an artificial kidney.

Cellophane and Salt Water

His expertise with blood banks would now come in handy. Handling blood in large volumes outside the body is not a trivial task, and doing so gave Dr. Kolff the confidence that a machine to do the job of a kidney was possible. He knew from his experiments that he’d need 10 meters of sausage casing, and that both the blood and the saline solution would need to be circulated. He built a drum from wooden slats and suspended it on an axle so that half its diameter was in a laundry tub. The cellophane tubing was wrapped around the drum and the tub was filled with saline. The tubing was filled with the patient’s blood, and a motor gently rotated the drum through the saline bath. When the blood had been cleaned, it would be returned to the patient.

A later version of Dr, Kolff’s artificial kidney, this one using 40 meters of cellophane tubing rather than the 10 meters of the prototype. Source: Rijksmuseum Boerhaave

The artificial kidney was crude, and initially not terribly effective. Of the first 15 patients treated with it in Kampen, only one survived, and Dr. Kolff admits she might have lived without the treatment. It would not be until 1945 that dialysis would have its first unequivocal success: a 67-year-old woman in prison for collaborating with the Nazis. Dr. Kolff was urged to let her die, but he dialyzed her and she came out of her coma. She survived for seven more years. The artificial kidney had proven itself.

Closer to the Heart

Dr. Kolff and a later version of his artificial implantable heart. Source: University of Utah

Having conquered dialysis and shared his designs freely with doctors all over the world, in 1950 Dr. Kolff was offered a job at the prestigious Cleveland Clinic. There his interests turned to other artificial organs, including the problems of open-heart surgery. At the time there was no way to bypass the heart during surgery, so he set about building one of the first membrane oxygenators, a machine that pumps blood over a porous plastic membrane to oxygenate the blood while removing carbon dioxide. This eventually let coronary artery bypass surgery become a common surgical procedure, with 200,000 performed in the United States alone every year.

Dr. Kolff also turned his inventive mind to the artificial heart. In fact, the first implantable artificial heart, the Jarvik-7, was one of Kolff’s designs. It was named after Dr. Robert Jarvik, one of Kolff’s students and the project manager on the team. In 1981 the Jarvik-7 was implanted in Barney Clark, who survived 112 days before succumbing to multiple systems failure.

Dr. Willem Kolff had a long and storied career, eventually retiring at age 86. His artificial organs, especially his artificial kidney, have saved countless lives, and continue to be used to this day. That they started with something as mundane as sausage casing and a laundry tub full of salt water only makes the achievement more impressive.

Pickaxe Controller Is Great For Minecraft, Just Aim Carefully

Minecraft started out as a lovable indie game, and became an unstoppable billion-dollar juggernaut in a remarkably quick fashion. Over time, it’s become a favorite among modders and those that seek to explore what’s possible with the game. [Eric] decided that the game could be more immersive, and built this awesome pickaxe controller.

The controller is built around an off-the-shelf Minecraft pickaxe toy; a popular piece of merchandise given the tool’s importance in the game. [Eric] added an Arduino, an accelerometer, and buttons. This lets the controller act as a mouse, allowing the user to control the camera by moving the pickaxe. The buttons unlock further functionality, with the red button allowing the user to mine by swinging the axe. Reportedly this is a lot of fun, albeit tiring in long sessions. Other features are still controlled by the keyboard, such as movement and accessing inventory screens. We’d love to try it out; carving out a tunnel block by block would be quite satisfying after all the exertion!

[Eric] is actually giving the controller away to a lucky subscriber, so head over to the Youtube video if you’d like a shot to own the nifty pickaxe. We’ve seen other advanced Minecraft controllers before, too. Video after the break.

Europeans Now Have The Right To Repair – And That Means The Rest Of Us Probably Will Too

As anyone who has been faced with a recently-manufactured household appliance that has broken will know, sometimes they can be surprisingly difficult to fix. In many cases it is not in the interests of manufacturers keen to sell more products to make a device that lasts significantly longer than its warranty period, to design it with dismantling or repairability in mind, or to make spare parts available to extend its life. As hardware hackers we do our best with home-made replacement components, hot glue, and cable ties, but all too often another appliance that should have plenty of life in it heads for the dump.

Czech waste management workers dismantle scrap washing machines. Tormale [CC BY-SA 3.0].Czech waste management workers dismantle scrap washing machines. Tormale [CC BY-SA 3.0].If we are at a loss to fix a domestic appliance then the general public are doubly so, and the resulting mountain of electrical waste is enough of a problem that the European Union is introducing new rules governing their repairability. The new law mandates that certain classes of household appliances and other devices for sale within the EU’s jurisdiction must have a guaranteed period of replacement part availability and that they must be designed such that they can be worked upon with standard tools. These special classes include washing machines, dishwashers, refrigerators, televisions, and more.

Let’s dig into the ramifications of this decision which will likely affect markets beyond the EU and hopefully lead to a supply of available parts useful for repair and beyond.

When A Large Customer Adopts Right To Repair, Everybody Does

The right to repair what we own has been a hot topic in our community for many years, and indeed has appeared in these pages many times. The recent legislation will not help in some of the key battlegrounds such as the use of DRM to restrict maintenance of John Deere tractors, but it will have a huge impact upon the domestic appliance market far beyond the EU borders. The union’s member states collectively represent such a significant market that these rules will affect the design of appliances sold in all markets, as the manufacture of these devices is now a global undertaking. Thus it is not unreasonable to expect that, for example, a Korean-made washing machine sold in Paris will have the same underpinnings as one sold in Miami, and that both machines will benefit from the same supply of replacement parts.

It's likely that parts suppliers such as espares will continue to sell parts to everyone, and not just the trade. It’s likely that parts suppliers such as espares will continue to sell parts to everyone, and not just the trade.

The story is not without a sting in the tail though, for within it is the news that those spare parts will not be made available to the consumer, instead they will only be released to the appliance repair trade. We see this as a regressive step, because by restricting repair to an anointed few it is hardly a universal right to repair, however we also expect that the usual online suppliers of appliance parts will happily sell to all comers and that a thriving grey market will spring up to fill any gap in the market. There is also the question of what it might do to the lower end of the appliance market, what would the spare parts burden do to the availability of the sub-$50 Chinese breadmaker for example? We would expect this to solve itself by manufacturers of low-end goods adopting a largely standard library of parts, however a concern is that it might push up the entry level for appliance ownership to the disadvatage of less well-heeled consumers.

That’s The Feelgood News Story, Now What About The Hardware Hacker Community?

This hydropower generator for off-grid living uses a washing machie motor. This hydropower generator for off-grid living uses a washing machine motor.

So far this has been a consumer story, but what about our world of hardware hackers? Going back to the start of this piece it is likely to mean that in future we more likely to be able to fix those dead appliances that cross our benches, but there is more in it for us. This measure will mean a bonanza of readily-available parts will come to market as spares, and while many of them will be restricted to their intended application there will be plenty that will have utility well beyond. Expect to see more brushless motors, valves, pumps, and more at mass-produced and grey market prices, and start thinking about how you might use them.

As this is being written the news streams are full of environmental protests, from Greta Thunberg to Extinction Rebellion to the Bolivian capital and it’s undeniable that they represent the prevailing zeitgeist. The European Right To Repair laws are not in the name of personal freedom but aimed at reducing environmental impact. There is a sunk cost of carbon emissions and other impacts in every product we produce. It is in the public interest to give each the longest life possible, and on balance this law aims to reduce waste through increased longevity with a repairability mindset. I think it is inevitable that we will see the same ethos spread to other jurisdictions and fields of manufacturing.

Dip Your Toes in the Open Water of Raspipool

If you’re lucky enough to have a swimming pool, well, you may not feel all that lucky. Pools are great to have on a hot summer day, but keeping them crystal clear and pH-balanced is a deep dive into tedium. Sure, there are existing systems out there. They cost a kiddie pool of cash and are usually limited to particular pool parts. Existing DIY solutions are almost as bad, and so [segalion] is making waves with a dumb, brand-agnostic pool automation system called Raspipool.

Sensors for pH, ORP, and temperature are immersed in pool water flowing through a bypass pipe that runs between the filter and the pump. The basic plan is to control the pumps and sensors with a web-enabled Raspberry Pi, and have the Pi send action and threshold notifications straight to [segalion]’s poolside lounge chair. Each piece is dedicated to a single task, which allows for easy customization and future expansion.

[segalion] is trying to get more people involved so that Raspipool can keep really make a splash. Be sure to check out the project wiki and let him know if you can help or have suggestions.

We’re glad [segalion] is building from the ground up, and doesn’t have to dive into some pre-existing mess of an automation system.

Soaring with the Sun: 4 Years of Solar RC Planes

Many of us have projects that end up spanning multiples years and multiple iterations, and gets revisited every time inspiration strikes and you’ve forgotten just how much work and frustration the previous round was. For [Daniel Riley] AKA [rctestflight] that project is a solar powered RC plane which to date spans 4 years, 4 versions and 13 videos. It is a treasure trove of information collected through hard experience, covering carbon fibre construction techniques, solar power management and the challenges of testing in the real world, among others.

Solar Plane V1 had a 9.5 ft / 2.9 m carbon fibre skeleton wing, covered with transparent film, with the fragile monocrystaline solar cells mounted inside the wing. V1 experienced multiple crashes which shattered all the solar cells, until [Daniel] discovered that the wing flexed under aileron input. It also did not have any form of solar charge control. V2 added a second wing spar to a slightly longer 9.83 ft / 3 m wing, which allowed for more solar cells.

Solar Plane V3 was upgraded to use a single hexagonal spar to save weight while still keeping stiff, and the solar cells were more durable and efficient. [Daniel] did a lot of testing to find an optimal solar charging set-up and found that using the solar array to charge the batteries directly in a well-balanced system actually works equally well or better than a MPPT charge controller.

V4 is a departure from the complicated carbon fibre design, and uses a simple foam board flying wing with a stepped KF airfoil instead. The craft is much smaller with only a 6 ft / 1.83 m wingspan. It performed exceptionally well, keeping the battery fully charged during the entire flight, which unfortunately ended in a crash after adjusting the autopilot. [Daniel] suspects the main reasons for the improved performance are higher quality solar panels and the fact that there is no longer film covering the cells.

We look forward to seeing where this project goes! Check out Solar Plane V4 after the break.

We’ve covered some of [Daniel]’s other projects before including GPS guided tupperware, a flying stick and a retina searing spotlight. We’ve also covered another flying wing.

Captivating Clock Tells Time With Tall Tubes

Time is probably our most important social construct. Our perception of passing time changes with everything we do, and when it comes down to it, time is all we really have. You can choose to use it wisely, or sit back and watch it go by. If you want to do both, build a clock like this one, and spectate in sleek, sophisticated style.

[ChristineNZ]’s mid-century-meets-steampunk clock uses eight ILC1-1/8Ls, which are quite possibly the largest VFD tubes ever produced (and still available as new-old stock). In addition to the time, it displays the date, relative humidity, and temperature in both Celsius and Fahrenheit. A delightful chime sounds every fifteen minutes to remind you that time’s a-wastin’.

The seconds slip by in HH/MM/SS format, each division separated by a tube dedicated to dancing the time away. The mesmerizing display is driven by an Arduino Mega and a MAX6921 VFD driver, and built into a mahogany frame. There isn’t a single PCB in sight except for the Mega — all the VFDs are mounted on wood and everything is wired point-to-point. Sweep past the break to see the progressive slideshow build video that ends with a demo of all the functions.

Those glowing blue-green displays aren’t limited to clocking time. They can replace LCDs, or be scrolling marquees.

Finding Pre-Trained AI In A Modelzoo Using Python

Training a machine learning model is not a task for mere mortals, as it takes a lot of time or computing power to do so. Fortunately there are pre-trained models out there that one can use, and [Max Bridgland] decided it would be a good idea to write a python module to find and view such models using the command line.

For the uninitiated, Modelzoo is a place where you can find open source deep learning code and pre-trained models. [Max] taps into the (undocumented) API and allows a user to find and view models directly. When you run a utility, it goes online and retrieves the categories and then details of the available models. From then on, the user can select a model and the application will simply open the corresponding GitHub repository. Sounds simple but it has a lot of value since the code is designed to be extendable so that users working on such projects may automate the downloading part as well.

We have seen projects with machine learning used to detect humans, and with AI trending community tools such as this one help beginners get started even faster.

October 08 2019

3D Printed Tools For Quick Press Brake Jobs

Press brakes are a workshop staple when working with sheet metal. They’re ideal for executing accurate and repeatable bends over and over again. Typically, they’re fitted with steel tooling that can hold up to thousands of press cycles. However, such tooling is expensive, and time consuming to produce. [Anthony] recently had a job come through the shop that required a unique internal radius. Rather than rush out and buy tooling, he decided to 3D print his own instead!

The press brake tools were printed on a standard Prusa i3, using regular PLA filament. There’s nothing particularly special in the process, with the prints using 12 perimeters and 20% infill. Despite being made of plastic, the tools held up surprisingly well. In testing, the parts were able to bend up to 3.4 mm steel, undergoing several cycles without major visible wear. [Anthony] also experimented with gooseneck parts, which, while less robust, make it easy to accommodate more complex sheet metal parts.

3D printing is a great way to produce custom press tooling, and can be done far more cheaply and quickly than producing traditional steel tooling. While it’s unlikely to be useful for long production runs, for short runs that need custom geometry, it’s a handy technique. We’ve even seen 3D printed punch-and-die sets, too. Video after the break.

Spinning ESP32 Display Puts The Customer First

Most of the projects we feature on Hackaday are built for personal use; designed to meet the needs of the person creating them. If it works for somebody else, then all the better. But occasionally we may find ourselves designing hardware for a paying customer, and as this video from [Proto G] shows, that sometimes means taking the long way around.

The initial task he was given seemed simple enough: build a display that could spin four license plates around, and make it so the speed could be adjusted. So [Proto G] knocked a frame out of some sheet metal, and used an ESP32 to drive two RC-style electronic speed controllers (ESCs) connected to a couple of “pancake” brushless gimbal motors. Since there was no need to accurately position the license plates, it was just a matter of writing some code that would spin the motors in an aesthetically pleasing way.

Unfortunately, the customer then altered the deal. Now they wanted a stand that could stop on each license plate and linger for a bit before moving to the next one. Unfortunately, that meant the ESCs weren’t up to the task. They got dumped in favor of an ODrive motor controller, and encoders were added to the shafts so the ESP32 could keep track of the display’s position. [Proto G] says he still had to work out some kinks, such as how to keep the two motors synchronized and reduce backlash when the spinner stopped on a particular plate, but in the end we think the results look fantastic. Now if only we had some license plates we needed rotisseried…

If [Proto G] knew he needed precise positioning control from the start, he would have approached the project differently and saved himself a lot of time. But such is life when you’re working on contract.

Making Music From Cardboard

Fans of MaKey MaKey may find this project similar, but there’s a lot more to the Mini Automat than making music from fruit.

The idea for the Mini Automat (which is an off-shoot of the original Automat project by [Dada Machines]) is to make music accessible to anyone. The device functions as a plug and play MIDI-controller that connects to a computer, MIDI workstation (keyboards and sequencers), or DAW for input and triggers actuators on the output to create music.

The modifications make the originally Automat more hackable by making the board compatible with Arduino and Circuit Python, as well as adding in digital and analog pins for connecting to sensors, buttons, or light systems.

The team has released all schematics, firmware, and software, with only the board layouts unreleased to the public. From solenoids that push, pull, jiggle, smash, and bash at drums to surfaces that vibrate screws and beads, there’s a huge variety of household objects that can be used to make complex layered musical compositions, even for a one-person musician.

 

The Berlin-based team works on open source music tech hardware with the hopes of bringing environmentally and financially sustainable ideas to market.

The HackadayPrize2019 is Sponsored by:

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Teardown: Quirky Egg Minder

Many of the biggest stars are hesitant to do sequels, believing that the magic captured the first time around is hard to reproduce in subsequent productions. As I’m known (at least around the former closet that now serves as my home office) as the “Meryl Streep of Teardowns”, I try to follow her example when it comes to repeat performances. But if they could get her to come back for another Mamma Mia film, I suppose I can take a look at a second Quirky product.

An elderly egg calls to inquire about euthanasia services.

This time around we’ll be looking at the Quirky Egg Minder, a smart device advertised as being able to tell you when your eggs are getting old. Apparently, this is a problem some people have. A problem that of course is best solved via the Internet of Things, because who wouldn’t pay $80 USD for a battery-powered WiFi device that lives in their refrigerator and communicates vital egg statistics to an online service?

As it turns out, the answer to that question is “most people”. The Egg Minder, like most of its Quirky peers, quickly became a seemingly permanent fixture of retailer’s clearance shelves. This particular unit, which I was able to pick up new from Amazon, only cost me $9.99. This is still more than I would have paid under normal circumstances, but such sacrifices are part and parcel with making sure the readers of Hackaday get their regular dose of unusual gadgetry.

You may recall that our last Quirky device, the “Refuel” propane tank monitor, ended up being a fantastically engineered and built piece of hardware. The actual utility of the product was far from certain, but nobody could deny that the money had been spent in all the right places.

What will the internals of the Egg Minder reveal? Will it have the same level of glorious over-engineering that took us by surprise with the Refuel? Will that zest for form over function ultimately become the legacy of these Quirky devices, or was it just a fluke? Let’s crack this egg and find out.

Separating the Yolk

The Egg Minder is held together with seven unnecessarily large screws, each hidden behind a rubber plug that blends in with the case so well that at first I thought they were potted in with some kind of epoxy. Curiously one of the screws had a T15 head, which I would normally attribute to some attempt at “security”, but it seems odd that Quirky would be worried about anyone taking a peek inside their electronic egg carton. There’s also a thick rubber gasket keeping the two halves of the plastic casing sealed, and a boot around the power switch. So far, that Quirky attention to detail is in full effect.

With the enclosure opened, we can see the bottom half is empty except for the battery compartment. I was actually a bit surprised they didn’t add some chunks of metal in there to give the device a bit more heft. The thing is responsible for holding your eggs after all, and keeping it more firmly planted to the shelf in the fridge seems like it would be worth the few cents to throw some ballast in there.

The top half was also a surprise: it’s not every day that you see the back of a single-sided PCB like this. Questions such as “Why?” and “How?” immediately came to mind.

Sunny Side Up

Flipping the PCB over, we can immediately see how they pulled it off. The board uses an incredible number of zero value resistors to “jump” over traces, allowing the entire circuit to be contained on the same side of the board. Rather than using a via to bring a trace to the other side whenever things got a little cramped, one of these resistors was used to physically lift the trace over its peers.

So now we know how they managed to contain such a complex SMD design on just one side of the board, but we still don’t know why. This is the part where we get to speculate a bit. The board has what is presumably a waterproof coating, but rather than being sprayed uniformly over the entire surface, it’s been carefully applied so as not to cover up any of the (numerous) surface mount LEDs.

If we imagine that a worker had to manually brush this coating onto the board, it makes sense that they’d want to keep everything on the same surface. Not only would it be faster for the worker, but it would allow the boards to be placed on their backs to dry rather than having to hang them and risk the coating running where it didn’t belong. But again, that’s just speculation. If somebody has a better theory, I’d love to hear it.

A Smart Egg

You may have noticed that, up until this point, I haven’t addressed how the Egg Minder actually works. That’s because, frankly, it doesn’t. Granted that might sound a little harsh, but the fact of the matter is that this device doesn’t actually tell you how old an egg is.

The optical sensor under each egg.

There’s no high-tech spectroscopy going on that can peer through the shell or anything like that. It simply keeps track of how many eggs are currently sitting in the fourteen openings on the top; it’s up to the user to accurately enter the date they were purchased into the smartphone application.

Accordingly, some of the reviews I saw online assumed that the Egg Minder was simply using pressure sensors to detect how many eggs were onboard. Which is certainly a logical enough conclusion. An array of microswitches that engage under the weight of the eggs is probably the most straightforward way to approach this problem, and is certainly how I would have tackled it if asked to come up with my own homebrew version.

But that’s not how Quirky did it. Their solution uses fourteen pairs of infrared emitters and sensors, complete with optics at the bottom of each egg cup, to detect the reflection off of the egg’s shell. At first glance it seems like overkill, but in all fairness, this method does allow detecting the eggs regardless of their weight. It could be that physical detection was found to be unreliable with eggs of various sizes, where as this optical method should work no matter how small the egg is.

Of course, there’s more to the Egg Minder than a bunch of IR sensors. At the heart of the device is an Electric Imp module, the same as we previously saw in the Refuel. Clearly Quirky was a fan of these modules, and at this point, I’m going to go out on a limb and say that all of their Internet-connected devices from this era are probably packing this same board. In a pre-ESP8266 world, the Electric Imp was a compelling way to jump on the IoT bandwagon without having to reinvent the wheel.

Hard Boiled

I couldn’t end this teardown without pointing out what’s easily my favorite aspect of the Egg Minder, and a perfect example of the sort of fanatical attention to detail that Quirky engineers had. Along the side of the device there’s a light sensor, which as far as I can tell, is there to determine when the plastic lid has been closed over the eggs. Though it may also be used to determine when the lights are off in the refrigerator, as presumably the Electric Imp will limit its attempts to communicate with the outside world once the refrigerator door is closed and it’s essentially locked inside of a Faraday cage.

In any event, the designers were apparently concerned that light emanating from inside the Egg Minder could interfere with the operation of this sensor. Considering each egg has not only an IR emitter under it, but LEDs indicate its relative age, it wasn’t an unwarranted concern. To prevent this they painted the area behind the sensor black and covered it with a piece of fabric, just to be extra sure that no light could bounce around and compromise their electronic egg counting device. Oh Quirky, we don’t deserve you.

Coming Full Circle (No Egg Pun)

In doing some research for this teardown, I found that this actually isn’t the first time the Quirky Egg Minder has graced the pages of Hackaday. Back in 2013, we wrote up a post about the then in-development Egg Minder, and asked readers to theorize how it might work and how they could build their own version.

With the final production hardware laid bare before us, it’s pretty interesting to go back and read those comments six years later. A number of folks guessed the device would be using an Electric Imp, and one commenter even correctly predicted it would come packed with lithium batteries due to the low temperatures it would need to operate in. A Quirky engineer even chimed in to say he was excited to see a project he was working on get picked up by Hackaday. Here’s hoping you’re still reading, Josh. You did us proud.

Celebrate Ada Lovelace Day by Catching Up on Stories of Science and Technology

Today is Ada Lovelace Day, a day to celebrate and encourage women in the fields of science and technology.

It’s a perfect time to look back and catch up on biographies of some incredible people whose stories have been featured over the past year. You’ll find a ton of those below, but while we have your attention we wanted to make an appeal to help shine some light onto those stories we have yet to feature in our Profiles in Science series. Let us know about women whose stories you’d like to see on Hackaday in the coming year by leaving a comment below. Of course, it’s not just today, we’re always looking for suggestions and the tips line is always open.

Getting a rocket engine off of the launch pad is itself a tricky proposition, but reaching an orbital velocity is an entirely different story. During the space race, the US was on the lookout for a fuel that could do the trick, and the answers came from a chemist who grew up in a small town in North Dakota then started a college degree before for a job at Plumb Brook Ordnance Works. Mary Sherman Morgan came through with the formulation for Hydyne that powered the Redstone Rocket project.

Also working in the aerospace realm, Elsie MacGill was known as the Queen of the Hurricanes. It’s not a quip on the weather, but a title she earned through her breakthroughs on the production lines for the Hurrican fighter planes during World War II. Her aeronautical engineering skills super-charged mass production of these aircraft and she went on to “write the book” on manufacturing aircraft at scale.

When we think of studying animals in the wild, Dian Fossey’s legacy looms large. Her story is one of dedication to scientific study and advocating for wildlife conservation. The former was a groundbreaking set of techniques Dian developed to study primates in their natural habitats. The latter made her efforts known far and wide through the publishing of her book Gorillas in the Mist, which was adapted as a movie after her death.

Want to talk about a breakthrough so fundamental that we take it for granted every day? Alice Catherine Evans’ work to make pasteurization of all milk a given at a time when many thought a healthy-looking cow could be trusted to produce low-bacteria milk. Her science showed the fallacy of this assumption and saved lives by first leading to milk grading practices and later to nearly universal pasteurization.

Remember the third Curie? Not Marie or Pierre, but still a scientist who worked on radioactivity? It was their daughter, Irene Joliot-Curie who made breakthroughs in artificial radiation and went on to win the Nobel prize along with her husband and lab partner Frederic. This discovery was key in developing radioactive materials for medical use.

It’s almost impossible to imagine a world without electronic music, but the field is really only a few generations old. Daphne Oram saw the potential for electronic music early on and in the 1940s and 50s she made monumental advances in adapting the cutting edge in electronics to making music. From hacking on newly invented tape recorders to building some of the earliest synthesizers and what we would today call circuit bending, Daphne was driving the evolution of the earliest electronic instruments and techniques.

Everywhere you look there are fascinating stories on how we got here as a society. But as I said before, we need your help discovering the scientists, engineers, and hackers behind them. On this Ada Lovelace Day we invite you to leave a comment below about some of your favorite stories of women who have made an impact on the world. We’d love to dig into these stories as part of our ongoing Profiles in Science series.

The Long History Of Fast Reactors And The Promise Of A Closed Fuel Cycle

The discovery of nuclear fission in the 1930s brought with it first the threat of nuclear annihilation by nuclear weapons in the 1940s, followed by the promise of clean, plentiful power in the 1950s courtesy of nuclear power plants. These would replace other types of thermal plants with one that would produce no exhaust gases, no fly ash and require only occasional refueling using uranium and other fissile fuels that can be found practically everywhere.

The equipment with which nuclear fission was experimentally proven in 1938.

As nuclear reactors popped up ever faster during the 1950s and 1960s, the worry about running out of uranium fuel became ever more present, which led to increased R&D in so-called fast reactors, which in the fast-breeder reactor (FBR) configuration can use uranium fuel significantly more efficiently by using fast neutrons to change (‘breed’) 238U into 239Pu, which can then be mixed with uranium fuel to create (MOX) fuel for slow-neutron reactors, allowing not 1% but up to 60% of the energy in uranium to be used in a once-through cycle.

The boom in uranium supplies discovered during the 1970s mostly put a stop to these R&D efforts, with some nations like France still going through its Rapsodie, Phénix and SuperPhénix designs until recently finally canceling the Generation IV ASTRID demonstrator design after years of trying to get the project off the ground.

This is not the end of fast reactors, however. In this article we’ll look at how these marvels of engineering work and the various fast reactor types in use and under development by nations like Russia, China and India.

The ‘fast’ part of fast reactors

As alluded to in the introduction, the speed of the neutrons in their fission process is what makes a “fast” reactor fast. Whereas light-water reactors (LWR: including PWR, BWR and SCWR) employ regular water as a neutron moderator, fast reactors do not. The neutrons that are emitted by 235U and other isotopes when they are subjected to a nuclear chain reaction normally travel at a significant speed. Interestingly enough, the speed at which a neutron travels determines the likelihood of it interacting with a specific nucleus.

The production of transuranic actinides in thermal neutron fission reactors. (CC-BY-SA-3.0)

This neutron cross-section property is used to categorize nuclides. When a nucleus absorbs a neutron and either keeps it or decays, it is said to have a capture cross section. Nuclides that fission (shatter) have a fission cross section. Other nuclides will simply scatter the neutron and are said to have a scatter cross section. Nuclides with large absorption cross sections are called neutron poisons, as they will simply absorb neutrons without decaying, essentially starving the nuclear reaction of neutrons.

A nuclide like that of 238U is interesting in that has a non-zero rating in each of those three cross-section categories, which at least partially explains why it makes for such a poor fuel for a LWR. This is quite unlike 235U, which has a solid fission cross section, but only at neutron speeds which are significantly lower than those of freshly emitted neutrons during the nuclear chain reaction. This means that the neutrons in a LWR have to be slowed down (reduced to ‘thermal’ speeds) for a fission process to be sustained.

Here the water finds itself amidst the fuel rods, with neutrons flying everywhere as the fission process has been kick-started by the startup neutron source. These fast neutrons readily collide with the hydrogen atoms in a water molecule, which causes the former to lose kinetic energy and as a result slow down. This allows them to then careen straight into another (or the same) fuel rod and successfully fission another 235U nuclide.

This property of water as moderator also acts as a safety feature. If the temperature in the core increases, the water will end up boiling, which causes it to turn into a gas, meaning fewer water molecules per volume and thus less moderating of neutrons, effectively reducing the rate of the nuclear chain reaction. This negative void coefficient is a common feature of all commercial reactors in use today, with noticeable exceptions being the infamous RBMK design and the heavy water-based Canadian CANDU reactors.

Breeding plutonium for fun and profit

Ring of nearly pure plutonium. (Credit: Los Alamos National Laboratory)

As mentioned earlier, 238U is a bit of an odd one when it comes to its neutron cross-section. Its triple-dipping means that it both absorbs and scatters neutrons in addition to the occasional fission event, with the former being significantly more prevalent. Upon capturing a neutron by a 238U nuclide, it transforms (transmutates) into 239Pu (and some 239Pu into 240Pu). This process also happens in an LWR reactor, but is done on purpose in a fast breeder reactor (FBR) to create plutonium.

A fast reactor omits the neutron moderator completely, as it requires the fast neutrons in order to convert as much of the 238U to 239Pu. In the FBR, an enriched 235U core is covered with a mantel of mostly 238U, which then slowly transmutates into mostly 239Pu and 240Pu, for use in MOX fuel. This means that the FBR is a relatively simple design, using either a cooling loop or pool design. Coolants used are generally a liquid metal or sodium-based coolant, as these are weak neutron moderators, while still possessing excellent heat transfer properties.

France’s fast reactors have been used to both generate electricity just like any other thermal plant, while also providing the plutonium needed for creating MOX fuel that can be used in its LWRs. A major reason for this process was energy independence, as France does not have significant uranium resources, this would have allowed it to obtain up to sixty times more energy out of the uranium it imports, allowing every kilogram of uranium to last sixty times as long.

Experimental Breeder Reactor II (EBR II), prototype to the US Integral Fast Reactor.

Other recent efforts involving fast reactors include the Integral Fast Reactor in the USA and Japan’s Monju (succeeded by the FNR Jouyou sodium-cooled fast reactor). A nice side-effect of breeding uranium fuel is that it significantly reduces the volume of the spent fuel at the end of a once-through fuel cycle, as much of the original 238U will have been burned as 239Pu fuel in the LWR. The spent fuel from LWRs can then be passed through an FBR again, to burn up ‘waste’ isotopes which LWRs cannot use, as well as to create more fuel for LWRs.

Unfortunately, fast reactors have the disadvantages of being more expensive than LWRs and the challenges of sodium-based cooling (mainly avoiding contact with water) have meant that since the 1970s crash in uranium prices, it’s generally more economically viable to create new fuel out of uranium ore and store or dump the spent fuel after a once-through run in an LWR.

Despite an LWR doing some breeding of its own, converting some of the 238U to plutonium, an LWR’s spent fuel still contains about 96% of the original uranium along with 3% of ‘waste’ isotopes and about 1% of plutonium isotopes.

Burn, baby, burn

While most fast reactors are used to breed fuel for LWRs, another type aims to use all of the fuel locally. This type of fast reactor is called a Fast-Neutron Reactor (FNR) and is essentially a different core configuration of the FBR design, with no fundamental differences. Any fast reactor can in theory be used to breed fuel and burn it.

Schematic of a sodium-cooled fast reactor.

Changing an FBR design to FNR involves removing the 238U blanket and installing stainless steel (or equivalent) neutron reflectors. In the resulting reactor, the produced neutrons are kept inside the core, keeping them available for new interactions with nuclides and continuing the fission process.

As a result, an FNR can effectively fission and transmutate the nuclides in the fuel until no significant amounts of actinides (which includes uranium and plutonium) remain. This can be combined with pyroprocessing, which can reprocess today’s spent fuel from LWRs for burn-up in FNRs, effectively closing the nuclear fuel cycle.

French Resistance

Not only cold economics have played a role in stifling fast reactor development in the West. Fast reactors have caught the attention of terrorists and politicians alike. The former is illustrated by the 1982 rocket attack by Chaïm Nissim on the Superphénix FBR with five RPG-7 shoulder-fired rocket-propelled grenades, as he believed that an FBR “can explode with their fast neutrons”. This particular FBR was a joint project between France, Italy and Germany, with originally the goal to build FBRs based on the Superphénix design in both France and Germany.

The Superphénix reactor building. (© Yann Forget / Wikimedia Commons / CC-BY-SA)

From the beginning the Superphénix faced strong political resistance by anti-nuclear groups, with the closure of this prototype reactor in 1998, at a time when anti-nuclear Green ministers were in charge of the French government. The only reason given was that the project wasn’t viable due to its ‘excessive costs’, being 9.1 billion Euro since 1976, or about 430 million Euro a year. This despite the reactor’s issues with the sodium loop having been resolved in 1996 and the reactor having made money by producing electricity during most of its operational lifespan.

Current development

The situation in the US, France and other Western countries contrasts sharply with that in the Soviet Union, China and India. Starting in 1973, the BN-350 FNR on the shores of the Caspian Sea in what is now Kazakhstan provided 135 MW of electricity and desalinated water to the nearby city of Aktau. It only shut down in 1994 because the operator had run out of funds to purchase more fuel. In 1999 the reactor was fully retired, after 26 years of service.

The BN-series of FNRs continued with the BN-600, which was constructed at Beloyarsk Nuclear Power Station in Russia. This uses a sodium pool-based design and has been in operation since 1980, providing 600 MW of power to the local grid. Despite suffering a few dozen minor issues mostly related to leaks in the sodium tubing, its operational history has been largely trouble-free despite being the second prototype in the BN-series.

The BN-800 FNR at Beloyarsk.

The BN-800 reactor, built at the same Beloyarsk site, is the final prototype in the BN-series, providing 85% reduction in operating costs over the LWR VVER-1200 reactor, with the BN-1200 intended to be the first mass-produced fast reactor. Construction of the first BN-1200 reactors is currently pending. China’s experimental CEFR FNR and CFR-600 pilot FNR are based on Russian BN-reactor technology. Russia is also working on a lead-cooled fast reactor, called BREST.

India has found itself with abundant thorium (232Th) resources, which has led to it focusing on an ambitious thorium-based development program alongside uranium reactors. The thorium program consists out of three parts. First, they produce plutonium from uranium using LWRs. Then a FNR creates 233U from 232Th while burning the plutonium. Finally, advanced heavy water reactors would use the resulting thorium as fuel, and the 233U and plutonium as driver fuels.

Other Generation IV FNR designs are also under development, such as the helium gas-cooled fast reactor (GFR).

Closing the fuel cycle

As mentioned earlier, FNRs are capable of using all of today’s spent fuel (often referred to as ‘nuclear waste’) as fuel. Combined with pyropocessing, this would allow for nuclear fission reactors to operate with practically zero waste, using up all uranium fuel, minor actinides and so on. This has been a major goal of Russia’s nuclear program, and is one of China’s, Japan’s and South Korea’s nuclear programs as well.

Along with efforts in the US (mostly Argonne National Laboratory and its IFR pyroprocessing), South Korea’s KAERI is actively working on closing South Korea’s fuel cycle. The goal is to separate the spent fuel from everything that is still viable as fuel, meaning everything that is still radioactive. Unfortunately cooperation between Russia and nations other than China, as well as between South Korea and Japan or China has been very limited on this type of research on mostly political grounds.

Despite this, it seems that efforts are well underway to make Generation IV FNRs the reactor of choice for new plants, not only allowing for spent fuel to be used up fully and closing the fuel cycle, but also increasing the energy we can obtain from uranium (and conceivably thorium) by many times, increasing even the pessimistic estimate of about 100 years of uranium fuel to a comfortable few-thousand years, while not leaving the world a legacy of spent uranium fuel.

August 22 2018

Hardware Store White Balance Reference

We live in a time in which taking pictures is preposterously easy: take out your phone (assuming it wasn’t already in your hands), point it at something, and tap the screen. The camera hardware and software in even basic smartphones today is good enough that you don’t need to give it much more thought than that to get decent pictures. But what if you want to do better than just decent?

Ideally you’d take photos lit by high temperature lights, but failing that, you might need to compensate by adjusting the white balance during post-processing. But to accurately adjust white balance you need a pure white reference point in the image. Thanks to some diligent research by the folks at the FastRawViewer blog, we now have a cheap and widely available source for a pure white reference material: PTFE pipe tape.

Alright, we know what you’re thinking: how hard could it be to find a white object? Well, if you’re talking about really white, it can actually be quite difficult. Take a walk down the paint aisle of your local hardware store and see just how many “whites” there actually are. Think the shirt your subject is wearing is really white? Think you can use the glossy white smartphone in their hand as a reference? Think again.

By taking a rubber eraser and wrapping it with a few layers of the PTFE tape, you can create a white reference that’s so cheap it’s effectively disposable. Which is good, because protecting your white reference object and keeping it clean can be a challenge in itself. But with a PTFE tape reference, you can just chuck the thing when the photo shoot is done.

Combine this cheap white reference with some of the DIY photography lighting setups we’ve covered in the past, and you’ll be well on the way to getting better images to document all your projects. Just remember to submit them to us when you’re done.

[Thanks to Keith Olson for the tip.]

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