Building new things in an existing city is hard. Usually, new development means tearing down existing structures. Doing so for apartment complexes or new skyscrapers is one thing, but infrastructure is much more complicated, both from an engineering perspective and an economical one. Not only do people not want to foot the tax bill for things they may not see an immediate benefit from, but it can be difficult to find the space for bigger roads, more pipelines, or subway tunnels in a crowded urban area. It’s even harder for infrastructure that most consider an eyesore, like a power plant or electric substation. It’s no surprise then that some of the largest cities in the world have been making use of floating power plants rather than constructing them on dry land.
The latest city to entertain a bid for a new floating power plant (FPP) is New York, which is seeking to augment its current fleet of barge-based power stations already in operation. It already operates the largest FPP in the world at Gowanus in Brooklyn, which is able to output 640 MW of electricity. There’s also a 320 MW plant nearby as well, and the new plants would add eight 76 MW generators to New York City’s grid.
Let’s take a look at what goes into these barge-based generator designs.
An Elegoo Mars resin 3D printer, straight to my doorstep for a few hundred bucks. What a time to be alive.
Resin-based 3D printers using digital light processing (DLP) and especially stereolithography (SLA) are getting more common and much more affordable. Prosumer-level options like Formlabs and the Prusa SL1 exist, but more economical printers like the Elegoo Mars, Anycubic Photon, and more can be had for a few hundred bucks. Many printers and resin types can even be ordered directly from Amazon, right at this moment.
Resin prints can look fantastic, so when does it make sense to move to one of these cheap resin printers? To know that, consider the following things:
The printing process and output of resin printers is not the same as for filament-based printers. Design considerations, pre-processing, and post-processing are very different.
Resin printing has a different workflow, with consumables and hidden costs beyond the price of resin refills.
Some hacks are born of genius or necessity, and others from our sheer ham-fisted incompetence. This is not a story about the first kind. But it did give me an excuse to show how easy it is to design WiFi-connected devices that work the way you want them to, rather than the way the manufacturer had in mind.
It started out as a sensible idea – consumer electronics in Vietnam have many different electric plug types for mains AC power: A, C, G, F, and I are fairly present, with A and C being most common. For a quick review of what all those look like, this website sums it up nicely. There are universal power adapters available of course, but they tend to fit my most common type (C) poorly, resulting in intermittent power loss whenever you sneeze. So I figured I should replace all the plugs on my devices to be A-type (common to those of you in North America), as it holds well in all the power bar types I have, mainly leftover server PDUs.
This was very straightforward until I got to my desk lamp. Being a fancy Xiaomi smart lamp, they had opted to hide a transformer in the plug with such small dimensions that I failed to notice it. So instead of receiving a balmy 12 volts DC, it received 220 volts AC. With a bright flash and bang, it illuminated my desk one final time.
If the current Administration of the United States has their way, humans will return to the surface of the Moon far sooner than many had expected. But even if NASA can’t meet the aggressive timeline they’ve been given by the White House, it seems inevitable that there will be fresh boot prints on the lunar surface within the coming decades. Between commercial operators and international competition, we’re seeing the dawn of a New Space Race, with the ultimate goal being the long-term habitation of our nearest celestial neighbor.
An Apollo astronaut covered in lunar dust
But even with modern technology, it won’t be easy, and it certainly won’t be cheap. While commercial companies such as SpaceX have significantly reduced the cost of delivering payloads to the Moon, we’ll still need every advantage to ensure the economical viability of a lunar outpost. One approach is in situ resource utilization, where instead of transporting everything from Earth, locally sourced materials are used wherever possible. This technique would not only be useful on the Moon, but many believe it will be absolutely necessary if we’re to have any chance of sending a human mission to Mars.
One of the most interesting applications of this concept is the creation of a building material from the lunar regolith. Roughly analogous to soil here on Earth, regolith is a powdery substance made up of grains of rock and micrometeoroid fragments, and contains silicon, calcium, and iron. Mixed with water, or in some proposals sulfur, it’s believed the resulting concrete-like material could be used in much the same way it is here on Earth. Building dwellings in-place with this “lunarcrete” would be faster, cheaper, and easier than building a comparable structure on Earth and transporting it to the lunar surface.
Now, thanks to recent research performed aboard the International Space Station, we have a much better idea of what to expect when those first batches of locally-sourced concrete are mixed up on the Moon or Mars. Of course, like most things related to spaceflight, the reality has proved to be a bit more complex than expected.
It’s fair to say that 2019 has not been a good year for the aircraft manufacturer Boeing, as its new 737 MAX aircraft has been revealed to contain a software fault that could cause the aircraft to enter a dive and crash. Now stories are circulating of another issue with the 737, some of the so-called “Pickle forks” in the earlier 737NG aircraft have been found to develop cracks.
It’s a concerning story and there are myriad theories surrounding its origin but it should also have a reassuring angle: the painstaking system of maintenance checks that underpins the aviation industry has worked as intended. This problem has been identified before any catastrophic failures have occurred. It’s not the story Boeing needs at the moment, but they and the regulators will no doubt be working hard to produce a new design and ensure that it is fitted to aircraft.
The Role of the Pickle Fork
For those of us who do not work in aviation though it presents a question: what on earth is a pickle fork? The coverage of the story tells us it’s something to do with attaching the wing to the fuselage, but without a handy 737 to open up and take a look at we’re none the wiser.
Fortunately there’s a comprehensive description of one along with a review of wing attachment technologies from Boeing themselves, and it can be found in one of their patents. US9399508B2 is concerned with an active suspension system for wing-fuselage mounts and is a fascinating read in itself, but the part we are concerned with is a description of existing wing fixtures on page 12 of the patent PDF.
A cross-section of the aircraft wing fixing, in which we’ve highlighted the role of the pickle forks. (Boeing)
The pickle fork is an assembly so named because of its resemblance to the kitchen utensil, which attaches firmly to each side of the fuselage and has two prongs that extend below it where they are attached to the wing spar.
For the curious engineer with no aviation experience the question is further answered by the patent’s figure 2, which provides a handy cross-section. The other wing attachment they discuss involves the use of pins, leading to the point of the patented invention. Conventional wing fixings transmit the forces from the wing to the fuselage as a rigid unit, requiring the fuselage to be substantial enough to handle those forces and presenting a problem for designers of larger aircraft. The active suspension system is designed to mitigate this, and we’d be fascinated to hear from any readers in the comments who might be able to tell us more.
We think it’s empowering that a science-minded general public can look more deeply at a component singled out in a news report by digging into the explanation in the Boeing patent. We don’t envy the Boeing engineers in their task as they work to produce a replacement, and we hope to hear of their solution as it appears.
Diesel is a fuel that has had a mixed history, with varying levels of take-up by consumers around the world. In the world of transport, diesel engines have offered better fuel economy and torque than comparable gasoline engines. Particularly popular in Europe, diesel established a strong consumer base in both small commuter cars as well as heavy vehicles such as trucks and buses.
Despite this, the tide is turning, and for the average motorist, diesel’s days may be numbered. Why is this the case, and what are the potential alternatives vying for diesel’s crown?
Plenty of Pros, but Plenty of Cons
Diesel remains a fuel with a varied uptake around the world. It has enjoyed great popularity in Europe in small commuter cars.
Diesel is a hydrocarbon fuel with several advantages over gasoline. Its lack of volatility makes it workable to use in a compression-ignition mode, and diesel engines can be run with lean fuel-air ratios. It also has a higher volumetric energy density than gasoline, and thanks to low volatility, diesel engines can run at significantly higher compression ratios without risking detonation. These benefits allow diesel engines to produce significantly more torque than similarly sized gasoline engines, and they can offer fuel economy gains in excess of 15%.
Unfortunately, diesel also comes with its fair share of drawbacks. Diesel engines are typically poor when it comes to power to weight ratio, as their high compression ratio and torque output demands heavier materials in their construction. The major bugbear of the diesel engine, however, is its emissions. Despite greater fuel efficiency, carbon dioxide output from a diesel engine is often far worse than that of a comparable gas motor. Additionally, their lean-burning nature leads to production of high levels of oxides of nitrogen (NOx), which have major negative environmental effects. There’s also the problem of particulate pollution, which is responsible for respiratory harm in humans. Diesel automobiles rank significantly worse than gasoline vehicles in all these areas. It’s begun to cause figurative headaches for the industry, and literal headaches for the public. Continue reading “The Future Of Diesel Is On Shaky Ground”→
Precision time is ubiquitous today thanks to GPS and WWVB. Even your Macbook or smartphone displays time which is synchronized to the NIST-F1 clock, a cesium fountain atomic clock (aka the ‘Atomic Clock’) that is part of a global consortium of atomic clocks known as Coordinated Universal Time (UTC). Without precise timing there would be train collisions, markets would tumble, schools would not start on time, and planes would fall out of the sky.
But how was precision timing achieved in the 19th century during the era of steam, brass, and solenoids? One of the first systems of precision timing kept trains running safely and on time, rang the bells at school, and kept markets trading by using a special clock designed by the Self Winding Clock Company. Through measurements of celestial objects by the US Naval Observatory, and time synchronization pulses broadcast by the Western Union telegraph network, this system synchronized time across the United States in an era where the speed of our train system was out-pacing by the precision of our clocks.
Those clocks were designed so well that many of them are still around and functioning. One of these 100-year-old self-winding clocks made its way onto my workbench. I did what any curious hacker would do, figured out how the synchronization worked and connected it to a clock source with atomic precision. Let’s take a look!
