All Dressed Up And Nowhere To Flow: Russia’s Nord Stream 2 Pipeline

April 24, 2022 by Ryan Flowers 37 Comments

At over 1230 km (764 mi) in length, $10 billion in cost, and over a decade in the making, the Nord Stream 2 pipeline was slated to connect the gas fields of Russia to Western Europe through Germany. But with the sanctions against Russia and the politics of the pipeline suffering a major meltdown, this incredible feat of engineering currently sits unused. What does it take to lay so much underwater pipe, and what challenges are faced? [Grady] over at Practical Engineering lays out out nicely for us in the video below the break.

A Bubble Curtain containing the disposal of WW2 ordinance

As with any undersea pipeline or cable, a survey had to be done. Instead of just avoiding great chasms, underwater volcanos, or herds of sharks with lasers, planners had to contend with culturally important shipwrecks, territorial waters, and unexploded ordnance dating from the second world war. Disposing of this ordinance in a responsible way meant employing curtains of bubbles around the explosion to limit the propagation of the explosion through the water- definitely a neat hack!

Speeding up the job meant laying several sections of pipe at once, and then tying them together after they were laid. The sheer amount of engineering, manpower and money involved are nothing short of staggering. Of course [Grady] makes it sound simple, and even shares his take on some of the geopolitical issues involved, such as Germany refusing to certify the line for use after the Russian invasion of Ukraine. So far, the $10 billion pipeline is unused, and even Shell has walked away from its $5 billion investment.

Be sure to watch the whole video for even more fascinating details about the Nord Stream 2’s amazing engineering and construction. Check out a Robot Eel concept for the maintenance of underwater pipelines too.

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High Temp Heat Engine Achieves 40% Efficiency

April 23, 2022 by Al Williams 17 Comments

People generate lots of waste heat. It makes sense that there is a desire to convert that heat into usable energy. The problem is one of efficiency. Researchers from MIT and the National Renewable Energy Lab have announced a new heat converter that they claim has 40% efficiency. Of course, there’s a catch. The temperature range for the devices starts at 1,900 °C .

The thermophotovoltaic cells are tandem devices with two cells mated on one substrate. Each cell is multiple layers of very thin and somewhat exotic materials. So this probably isn’t something you will cobble up in your basement anytime soon unless you’re already manufacturing ICs down there. It appears that the secret is in the multiple layers including a reflective one that sends any missed photons back through the stack.

The paper is pretty dense, but there’s a Sunday-supplement summary over on the MIT site. Using heat storage leads to the ability to make heat batteries, more or less, and harness what would otherwise be waste energy.

We’ve noticed a lot of interest in drawing power from hot pipes lately. All of them techniques we’ve seen rely on some kind of exotic materials.

Mercury Thrusters: A Worldwide Disaster Averted Just In Time

April 18, 2022 by Zoe Skyforest 60 Comments

The field of space vehicle design is obsessed with efficiency by necessity. The cost to do anything in space is astronomical, and also heavily tied to launch weight. Thus, any technology or technique that can bring those figures down is prime for exploitation.

In recent years, mercury thrusters promised to be one such technology. The only catch was the potentially-ruinous environmental cost. Today, we’ll look at the benefits of mercury thrusters, and how they came to be outlawed in short order.

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Scientists Are Now Declaring New Species Via Photos And Video

April 12, 2022 by Zoe Skyforest 22 Comments

Identifying new species is key to the work of zoologists around the world. It’s an exciting part of research into the natural world, and being the first to discover a new species often grants a scientists naming rights that can create a legacy of one’s work that lasts long into the future.

Traditionally, the work of taxonomy involved capturing and preserving an example of the new species. This is such that it could be classified properly and studied in detail by scientists working now and in the future. However, times are changing, and scientists are beginning to identify new species on the basis of videos and photos instead.

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A Super Simple DIY Ozone Generator

April 10, 2022 by Dave Rowntree 39 Comments

[Advanced Tinkering] needed a source of fresh ozone for some future chemistry related projects, and since buying an off-the-shelf unit would be, well, just plain boring, it was obvious what to do (Video, embedded below).

Wire mesh discharge surfaces separated with a glass tube

The concept of the corona-discharge ozone generator is pretty straightforward — a high-voltage AC potential is presented over a large surface area, such that any O₂ in the vicinity has the chance to get a decent dose of electrons ripping it apart and enabling the formation of the desired O₃.

The construction is quite simple, just a pair of cylindrical metal wire mesh electrodes, separated by a glass tube, with a second glass tube surrounding the whole assembly. The use of high voltage AC allows the discharge to form by capacitive coupling across the central tube, giving a very simple construction. A pair of 3D-printed PLA end caps complete the reaction vessel, although it is noted in the video that the PLA is not terribly resistant to the corrosive effects of ozone, and time will tell whether these go the whole mileage.

Feed oxygen from an external generator is pumped into one end cap, at the bottom, with ozone-enriched gas passing out the other end, at the top, giving the gas a more complex path through the assembly and maximizing the contact with discharge. It will be interesting to see what the produced ozone will be used for in these future projects.

We’ve not seen a vast number of ozone hacks, but we’re no strangers to high voltage applications, like this interesting hand disinfection device, and this simple hack that generates a six-figure voltage with little more than some glasses of water, well not much more anyway.

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Best Ways To Make PCB Breakaway Tabs, Revealed

April 9, 2022 by Donald Papp 20 Comments

Most of us are familiar with the concept of producing PCBs in a panel, and snapping them apart afterwards. V-grooves that go most of the way through a PCB are one way to go about this, but a line of perforations along which to snap a tab is another. But what’s the best size and spacing of holes to use? Sparkfun’s [Nick Poole] spent some $400 on PCBs to get some solid answers by snapping each of them apart, and judging the results.

The nice thing about creating a perforation line (or “mouse bites”) is that drill hits are a very normal thing in PCB production, which makes creating this kind of breakaway tab a very straightforward and flexible method. However, it can be tricky to get results that are just right. Too sturdy, and breaking apart is a hassle. Too weak, and the board may break or twist before its time. On top of that, edges must also break cleanly. We’ve covered panelizing PCBs in this way before, but this is the first time we’ve seen someone seriously look into how to create optimal breakaway tabs.

Placing holes tangent to the board edge (as shown above) isn’t the prettiest, but keeps PCB edges free from protrusions. This is best for boards that are rail-mounted, or have tight enclosures.

Data on designing mouse bites was sparse and a bit inconsistent, so [Nick] decided to figure it out empirically and share the results. The full details are available in Building a Better Mousebite (PDF download) but the essence of the recommendations are: 0.015″ unplated holes, spaced 0.025″ apart (center-to-center), tabs a maximum of 0.118″ wide (so as to be compatible with depanelizing tools), and holes that extend into the corners of the breakaway tab to avoid sharp edges. Holes should be placed slightly differently depending on whether one wishes to optimize the cosmetic appearance versus the physical smoothness of the board edge, but those numbers are the core of the guidelines.

To fine tune, [Nick] suggests increasing the spacing between holes to add strength, or just adding additional tabs. What about thickness of PCB? [Nick] tested boards both 0.8 mm and 1.6 mm thick, and while different amounts of torque were needed to snap the boards apart, things still worked as expected regardless of PCB thickness.

When it comes down to it, the best numbers will ultimately be the ones that your process or fab house can most efficiently handle, but [Nick]’s numbers should not steer anyone wrong, and it’s fantastic to see this kind of work go into refining such a common PCB feature.

Night Vision: Now In Color

April 9, 2022 by Al Williams 36 Comments

We’ve all gotten used to seeing movies depict people using night vision gear where everything appears as a shade of green. In reality the infrared image is monochrome, but since the human eye is very sensitive to green, the false-color is used to help the wearer distinguish the faintest glow possible. Now researchers from the University of California, Irvine have adapted night vision with artificial intelligence to produce correctly colored images in the dark. However, there is a catch, as the method might not be as general-purpose as you’d like.

Under normal illumination, white light has many colors mixed together. When light strikes something, it absorbs some colors and reflects others. So a pure red object reflects red and absorbs other colors. While some systems work by amplifying small amounts of light, those don’t work in total darkness. For that you need night vision gear that illuminates the scene with infrared light. Scientists reasoned that different objects might also absorb different kinds of infrared light. Training a system on what colors correspond to what absorption characteristics allows the computer to reconstruct the color of an image.

The only thing we found odd is that the training was on printed pictures of faces using a four-color ink process. So it seems like pointing the same camera in a dark room would give unpredictable results. That is, unless you had a huge database of absorption profiles. There’s a good chance, too, that there is overlap. For example, yellow paint from one company might look similar to blue paint from another company in IR, while the first company’s blue looks like something else. It is hard to imagine how you could compensate for things like that.

Still, it is an interesting idea and maybe it will lead to some other interesting night vision improvements. There could be a few niche applications, too, where you can train the system for the expected environment and the paper mentions a few of these.

Of course, if you have starlight, you can just use a very sensitive camera, but you still probably won’t get color. You can also build your own night vision gear without too much trouble.