Saltwater is plentiful, but no good for drinking. Desalinization is the obvious solution, but a big problem isn’t taking the salt out, it’s where all that leftover salt goes. Excess salt accumulates, crystallizes, collects, and clogs a system. Dealing with this means maintenance, which means higher costs, which ultimately limits scalability.
The good news is that engineers at MIT and in China have succeeded in creating a desalination system that avoids this problem by intrinsically flushing accumulated salt as it is created, keeping the system clean. And what’s more, the whole thing is both scalable and entirely passive. The required energy all comes from gravity and the sun’s heat.
To do this, the device is constructed in such a way that it mimics the thermohaline circulation of the ocean on a small scale. This is a process in which temperature and density differentials drive a constant circulation and exchange. In the team’s system, this ultimately flushes concentrations of salt out of the system before it has a chance to collect.
The entirely passive nature of the device, its scalability, and the fact that it could desalinate water without accumulating salt for years means an extremely low cost to operate. The operating principle makes sense, but of course, it is careful engineering that shows it is actually possible. We have seen projects leveraging the passive heating and circulation of water before, but this is a whole new angle on letting the sun do the work.
If you’re an Android fan, there’s a good chance you’ve heard of the Nexus 5X. The last entry in Google’s line of low-cost Nexus development phones should have closed the program on a high note, or at the very least maintained the same standards of quality and reliability as its predecessor. But unfortunately, a well known design flaw in the Nexus 5X means that the hardware is essentially a time-bomb. There are far too many reports of these phones entering into an endless bootloop right around the one year mark to say it’s just a coincidence.
The general consensus seems to be that faulty BGA chip soldering on the CPU works lose after about a year or so of thermal stress. Whatever the reason, [hillbillysam] recently found himself the proud owner of a dead Nexus 5X. Resigned to the fact that he would need to get a new phone, he at least wanted to get some of his data off the device before it went to that big landfill in the sky.
As it turns out these bootlooped phones can temporarily be revived by cooling them down, say by putting them in the freezer for a few hours. There’s plenty of debate as to why this works, but even our own [Lewin Day] can testify that it does seem to get the phone booting again; though only until it comes back up to operating temperature. With this in mind, [hillbillysam] reasoned that if he kept the phone as cold as possible while it was running, it may stay operational long enough for him to pull his files off of it over USB.
He couldn’t exactly freeze the phone in a block of ice, but remembering his high school chemistry, he came up with something pretty close. By adding salt to water, you can significantly lower temperature at which it freezes. Putting the phone into a watertight bag and submerging it in this supercooled solution is an easy and non-destructive way of keeping it very cold while still being accessible over USB.
His Nexus 5X was able to keep kicking the whole time it was luxuriating in its below-freezing saltwater bath, giving him plenty of time to copy everything he needed. It doesn’t sound like the kind of spa day we’d like to have personally, but to each their own.
A core part of the hacker mentality is the desire to test limits: trying out ideas to see if something interesting, informative, and/or entertaining comes out of it. Some employees of Andrews & Arnold (a UK network provider) applied this mentality towards connecting their ADSL test equipment to some unlikely materials. The verdict of experiment: yes, ADSL works over wet string.
ADSL itself is something of an ingenious hack, carrying data over decades-old telephone wires designed only for voice. ADSL accomplished this in part through robust error correction measures keeping the bytes flowing through lines that were not originally designed for ADSL frequencies. The flow of bytes may slow over bad lines, but they will keep moving.
How bad? In this case, a pair of strings dampened with salty water. But there are limits: the same type of string dampened with just plain water was not enough to carry ADSL.
The pictures of the test setup also spoke volumes. They ran the wet string across a space that looked much like every hacker workspace, salt water dripping on the industrial carpet. Experimenting and learning right where you are, using what you have on hand, are hallmarks of hacker resourcefulness. Fancy laboratory not required.
The Peachy Printer, originally a crowdfunding campaign for a $100 stereolithography 3D printer, is now dead in the water.[Rylan Grayston], the creator of the Peachy Printer, announced that [David Boe] — investor, 50% owner of Peachy Printer, and business partner — had stolen over $300,000 in Kickstarter campaign funds. According to [Rylan], this money was used to build a house.
An example print from the Peachy Printer Kickstarter campaign
When the Peachy Printer was announced on Kickstarter, it was, by any measure, a game changing product. Unlike other stereolithographic printers like the Form 1 and DLP projector kit printers, the Peachy was cheap. It was also absurdly clever. Instead of using a stepper motor to raise a print out of a vat of resin, the Peachy Printer floated the resin on a vat of salt water. By slowly dripping salt water into this vat, the level of the resin rose up, allowing the galvanometers and laser diode to print the next layer of a 3D object. In our first coverage of the Peachy Printer, everyone was agog at how simple this printer was. It wasn’t a high-resolution printer, but it was a 3D resin printer that only cost $100. Even today, nearly three years after the launch of the Kickstarter campaign, there’s nothing like it on the market.
For the last two years, [Rylan] appeared to have the Peachy Printer in a pseudo-stealth mode. Whispers of the Peachy Printer circled around 3D printer forums, with very little information coming from [Rylan]. For the last year, the Peachy Printer appeared to be just another failed crowdfunded 3D printer. Either [Rylan] didn’t have the engineering chops to take a novel device to market, there were problems with suppliers, or [Rylan] just couldn’t get the product out the door.
In the update published to the Kickstarter campaign, the reason for the failure of Peachy Printer to deliver becomes apparent. The Kickstarter campaign was set up to deliver the funds received – $587,435.73 – directly into [David Boe]’s account. Thirty days after the funds were received, [David] had spent over $165,000. In just over three months, all the Kickstarter funds, save for $200,000 transferred into the Peachy Printer corporate account, were spent by [David].
With no funds to complete the development of the Peachy Printer, [Rylan] looked into alternative means of keeping the company afloat until Kickstarter rewards had shipped. Peachy Printer received two government grants totalling $90,000 and $135,000. In March of 2015, one of [Rylan]’s family members loaned $50,000 to Peachy Printer. A plan to finance the delivery of Kickstarter rewards with new sales – a plan that is usually looked down upon by Kickstarter backers – was impossible, as cost and time required of certifying the laser in the Peachy Printer would have put the company in the red.
Right now, [Rylan] and the Peachy Printer are pursuing repayment from [David Boe], on the basis that Kickstarter reward money is still tied up in the construction of a house. Once the house is complete, the bank will disburse funds from the construction mortgage, and funds can then be transferred from [David] to Peachy Printer.
In all, the Peachy Printer is a mess, and has been since the Kickstarter funds were disbursed to [David]. There is – potentially – a way out of this situation that gets Peachy Printers into the hands of all the Kickstarter backers if the mortgage construction funds come through and production resumes, but that’s a lot of ‘ifs’. Failed Kickstarter projects for 3D printers are nothing new, but [Rylan]’s experience with the Peachy Printer is by far the most well-documented failure of a crowdfunding project we’ve ever seen.
The good news is that engineers at MIT and in China have succeeded in creating a desalination system that avoids this problem by intrinsically flushing accumulated salt as it is created, keeping the system clean. And what’s more, the whole thing is both scalable and entirely passive. The required energy all comes from gravity and the sun’s heat.
