Self-Healing Concrete: What Ancient Roman Concrete Can Teach Us

Concrete is an incredibly useful and versatile building material on which not only today’s societies, but also the ancient Roman Empire was built. To this day Roman concrete structures can be found in mundane locations such as harbors, but also the Pantheon in Rome, which to this day forms the largest unreinforced concrete dome in existence at 43.3 meters diameter, and is in excellent condition despite being being nearly 1,900 years old.

Even as the Roman Empire fell and receded into what became the Byzantine – also known as the Eastern Roman – Empire and the world around these last remnants of Roman architecture changed and changed again, all of these concrete structures remained despite knowledge of how to construct structures like them being lost to the ages. Perhaps the most astounding thing is that even today our concrete isn’t nearly as durable, despite modern inventions such as reinforcing with rebar.

Reverse-engineering ancient Roman concrete has for decades now been the source of intense study and debate, with a recent paper by Linda M. Seymour and colleagues adding an important clue to the puzzle. Could so-called ‘hot mixing’, with pockets of reactive lime clasts inside the cured concrete provide self-healing properties?

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Why A Community Hackerspace Should Be A Vital Part Of Being An Engineering Student

Travelling the continent’s hackerspaces over the years, I have visited quite a few spaces located in university towns. They share a depressingly common theme, of a community hackerspace full of former students who are now technology professionals, sharing a city with a university anxious to own all the things in the technology space and actively sabotaging the things they don’t own. I’ve seen spaces made homeless by university expansion, I’ve seen universities purposefully align their own events to clash with a hackerspace open night and discourage students from joining, and in one particularly egregious instance, I’ve even seen a university take legal action against a space because they used the name of the city, also that of the university, in the name of their hackerspace. I will not mince my words here; while the former are sharp practices, the latter is truly disgusting behaviour.

The above is probably a natural extension of the relationship many universities have with their cities, which seems depressingly often to be one of othering and exclusion. Yet in the case of hackerspaces I can’t escape the conclusion that a huge opportunity is being missed for universities to connect engineering and other tech-inclined students with their alumni, enhance their real-world skills, and provide them with valuable connections to tech careers.

Yesterday I was at an event organised by my alma mater, part of a group of alumni talking to them about our careers.  At the event I was speaking alongside an array of people with varying careers probably more glittering than mine, but one thing that came through was that this was something of a rare opportunity for many of the students, to talk to someone outside the university bubble. Yet here were a group of engineers, many of whom had interesting careers based locally, and in cases were even actively hiring. If only there were a place where these two groups could informally meet and get to know each other, a community based on a shared interest in technology, perhaps?

It’s not as though universities haven’t tried on the hackerspace front, but I’m sad to say that when they fill a room with cool machines for the students they’re rather missing the point. In some of the cases I mentioned above the desire to own all the things with their own students-only hackerspace was the thing that led to the community hackerspaces being sabotaged. Attractive as they are, there’s an important ingredient missing, they come from a belief that a hackerspace is about its facilities rather than its community. If you were to look at a room full of brand-new machines and compare it with a similar room containing a temperamental Chinese laser cutter and a pair of battered 3D printers, but alongside a group of seasoned engineers in an informal setting, which would you consider to be of more benefit to a student engineer? It should not be a difficult conclusion to make.

Universities value their local tech industry, particularly that which has some connection to your university. You want your students to connect with your alumni, to connect with the local tech scene, and to ultimately find employment within it. At the same time though, you’re a university, you see yourselves as the thought leader, and you want to own all the things. My point is that these two positions are largely incompatible when it comes to connecting your engineering students with the community of engineers that surround you, and you’re failing your students in doing so.

Thus I have a radical proposal for universities. Instead of putting all your resources on a sterile room full of machines for your students, how about spending a little into placing them in a less shiny room full of professional engineers on their off-time? Your local hackerspace is no threat to you, instead it’s a priceless resource, so encourage your students to join it. Subsidise them if they can’t afford the monthly membership, the cost is peanuts compared to the benefit. Above all though, don’t try to own the hackerspace, or we’re back to the first paragraph. Just sometimes, good things can happen in a town without the university being involved.

PCIe For Hackers: Extracting The Most

So, you now know the basics of approaching PCIe, and perhaps you have a PCIe-related goal in mind. Maybe you want to equip a single-board computer of yours with a bunch of cheap yet powerful PCIe WiFi cards for wardriving, perhaps add a second NVMe SSD to your laptop instead of that Ethernet controller you never use, or maybe, add a full-size GPU to your Raspberry Pi 4 through a nifty adapter. Whatever you want to do – let’s make sure there isn’t an area of PCIe that you aren’t familiar of.

Splitting A PCIe Port

You might have heard the term “bifurcation” if you’ve been around PCIe, especially in mining or PC tinkering communities. This is splitting a PCIe slot into multiple PCIe links, and as you can imagine, it’s quite tasty of a feature for hackers; you don’t need any extra hardware, really, all you need is to add a buffer for REFCLK. See, it’s still needed by every single extra port you get – but you can’t physically just pull the same clock diffpair to all the slots at once, since that will result in stubs and, consequently, signal reflections; a REFCLK buffer chip takes the clock from the host and produces a number of identical copies of the REFCLK signal that you then pull standalone. You might have seen x16 to four NVMe slot cards online – invariably, somewhere in the corner of the card, you can spot the REFCLK buffer chip. In a perfect scenario, this is all you need to get more PCIe out of your PCIe.

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Weird Electric Jet Skis Are Hitting The Waves

When it comes to reducing emissions from human sources, we’re at the point now where we need to take a broad-based approach. It’s not enough to simply make our cars more efficient, or start using cleaner power plants. We need to hit carbon zero, and thus everything has to change.

To that end, even recreational watercraft are going electric in this day and age. Several companies are developing motor-powered models that deliver all the fun without the emissions. But to do that, they’re taking to the air.

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Feeling The Heat: Railway Defect Detection

On the technology spectrum, railroads would certainly seem to skew toward the brutally simplistic side of things. A couple of strips of steel, some wooden ties and gravel ballast to keep everything in place, some rolling stock with flanged wheels on fixed axles, and you’ve got the basics that have been moving freight and passengers since at least the 18th century.

But that basic simplicity belies the true complexity of a railway, where even just keeping the trains on the track can be a daunting task. The forces that a fully loaded train can exert on not only the tracks but on itself are hard to get your head around, and the potential for disaster is often only a failed component away. This became painfully evident with the recent Norfolk Southern derailment in East Palestine, Ohio, which resulted in a hazardous materials incident the likes of which no community is ready to deal with.

Given the forces involved, keeping trains on the straight and narrow is no mean feat, and railway designers have come up with a web of sensors and systems to help them with the task of keeping an eye on what’s going on with the rolling stock of a train. Let’s take a look at some of the interesting engineering behind these wayside defect detectors.

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Europe’s Proposed Right-To-Repair Law: A Game Changer, Or Business As Usual?

Recently, the European Commission (EC) adopted a new proposal intended to enable and promote the repair of a range of consumer goods, including household devices like vacuum cleaners and washing machines, as well as electronic devices such as smartphones and televisions. Depending on how the European Parliament and Council vote in the next steps, this proposal may shape many details of how devices we regularly interact with work, and how they can be repaired when they no longer do.

As we have seen recently with the Digital Fair Repair Act in New York, which was signed into law last year, the devil is as always in the details. In the case of the New York bill, the original intent of enabling low-level repairs on defective devices got hamstrung by added exceptions and loopholes that essentially meant that entire industries and types of repairs were excluded. Another example of ‘right to repair’ being essentially gamed involves Apple’s much-maligned ‘self repair’ program, that is both limited and expensive.

So what are the chances that the EU will succeed where the US has not?

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Plan To Jam Mobile Phones In Schools Is Madness

Mobile phones in schools. If you’re a teacher, school staffer, or a parent, you’ve likely got six hundred opinions about this very topic, and you will have had six hundred arguments about it this week. In Australia, push has come to shove, and several states have banned the use of mobile phones during school hours entirely. Others are contemplating doing the same.

In the state of New South Wales, the current opposition party has made it clear it will implement a ban if elected. Wildly, the party wants to use mobile phone jamming technology to enforce this ban whether students intend to comply or not. Let’s take a look at how jammers work in theory, and explore why using them in schools would be madness in practice.

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