A concrete tie deforming under the weight of rail traffic. The arrow indicates where shape memory alloys were inserted to demonstrate adaptive reinforcement. Credit: University of Illinois Grainger College of Engineering
In railroad tracks, rail ties hold the rails in place and ensure that their separation does not change. Modern concrete ties warp and crack through repeated use, leading to safety concerns including derailment if not regularly maintained.
Research from The Grainger College of Engineering at the University of Illinois Urbana-Champaign shows that damage to concrete ties can be mitigated using shape memory alloys (SMAs), metals with the ability to return to their original shape after they are deformed.
In a study led by civil and environmental engineering professor Bassem Andrawes, ties warped by simulated rail traffic were shown to return to their original state with the help of SMAs activated by induction heating. The paper, “Experimental Testing of Concrete Crossties Prestressed with Shape Memory Alloys,” is published in the Journal of Transportation Engineering, Part A: Systems.
“We’re doing something that I think is unprecedented in rail transportation engineering,” Andrawes said. “We’re working with a commercial supplier of concrete rail ties to implement and test our designs. For our publication, we went beyond laboratory experiments and demonstrated compliance with rail industry standards. We’re very excited to continue our industrial partnership and develop a practical, working design.”
Degradation in concrete is traditionally prevented through the process of prestressing, in which pre-tensioned steel rods are inserted to exert forces which counteract the effects of heavy loads. While this technique is applied in rail ties, the difficulty is that different parts of the tie experience different stresses. In addition, the ties shift as the ballast—the gravel bed distributing weight and providing drainage—settles in response to traffic.
Andrawes believes that SMAs are an ideal solution because they can be inserted into ties then independently controlled with self-contained heat sources. The reinforcement they provide could quickly adapt to the specific circumstances the tie is experiencing at different locations in its structure.
“SMAs are examples of what we call ‘smart materials,'” Andrawes said. “You can deform them, twist them into wild new shapes, but they retain the memory of their original state in the molecular structure. When you apply heat, they know to return to that state. So, if you just have a heat source, then the SMA can guide a concrete structure back to the desired shape stored in the alloy’s memory.”
Working with Illinois Grainger Engineering civil and environmental engineering graduate student Ernesto Pérez-Claros, Andrawes decided to use induction heating, in which the heat to restore the SMAs to their original shape is provided by a time-varying electromagnetic field. This was done to ensure that the electrical hardware would not need to be inserted inside the tie.
The research proceeded in three phases. First, the researchers worked with Rocla Concrete Tie, Inc., to cast their design in commercially available concrete rail ties. Second, the researchers conducted laboratory experiments to quantify the impacts of different lengths of SMAs in the ties. Finally, ties were subjected to stress tests simulating rail traffic, and the prototypes exceeded the standards of the American Railway Engineering and Maintenance-of-Way Association (AREMA).
“It was important to us that we actually make something that goes out of the lab and into practice,” Andrawes said. “Showing that our design meets and even exceeds AREMA specifications means that it’s not just academic research. This is something that railroads can use, and we intend to guide it to the point where it can be adopted.”
The researchers plan to continue working with Rocla to commercialize the technology. They also plan to submit their prototypes for full testing with real rail traffic at the Federal Railroad Administration Transportation Technology Center in Pueblo, Colorado.
More information:
Ernesto Pérez-Claros et al, Experimental Testing of Concrete Crossties Prestressed with Shape Memory Alloys, Journal of Transportation Engineering, Part A: Systems (2025). DOI: 10.1061/jtepbs.teeng-8982
Citation:
Alloys that ‘remember’ their shape can prevent railroad damage (2025, October 30)
retrieved 30 October 2025
from https://techxplore.com/news/2025-10-alloys-railroad.html
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In 2012, San Francisco apparel shop American Giant released its very first product, a zip-up hooded sweatshirt that put the company on the map. Officially called the Classic Full Zip, most people know it as “the greatest hoodie ever made,” thanks to the headline on a Slate article touting its charms.
After that story, things took off for American Giant. In the 13 years since, the company has sold 1 million hoodies. It has also grown its brand and added a range of casual tops and bottoms, all of it sourced and manufactured in the US. But one thing that hasn’t changed much is the design of that Classic Full Zip hoodie. Until today.
The Classic Full Zip has just been relaunched as a softer and more breathable piece, thanks to an overall refresh centered around a new cotton fleece construction. The hallmarks of the design remain: the double-lined hood, stretchy side panels, and the elbow patches. But slip it on and zip it up, and you’ll notice it’s not as snug around the waist or around the shoulders.
For me, a big-shouldered person, the cut of the cotton around the shoulders was one of my quibbles with AG’s hoodie. I always liked the piece as a whole, but the fit wasn’t as relaxed as I’d like, and even after years of wear, it always felt a little stiff. The new design just gives you more room to move. The slightly more forgiving elastic in the cuffs around the wrists and waist is also something I consider an upgrade.
American Giant has been hailed as a success story for US-based manufacturing.
Photograph: American Giant
Inside one of the company’s factories.
Photograph: American Giant
The biggest upgrade, though, is to the cotton fleece itself. The fabric is softer and more breathable. This can be attributed to a change in the cotton fibers in the hoodie.
If you have a cheap, thick cotton T-shirt in your collection—probably something that has a heavy-metal band logo silkscreened to it—then you know it feels a little rough, and the shirt isn’t all that breathable. These cheaper shirts use short staple cotton fibers. The longer the fiber, the softer and more breathable the cotton gets. For this new fleece, AG is using the type of longer-staple cotton fibers found in soft cottony things like fancy dress shirts and expensive bedsheets.
The cotton in the fleece is grown, spun, and dyed in the US.
Photograph: American Giant
Cotton gets dyed at an American Giant factory.
Photograph: American Giant
At launch, the original Classic Full Zip Hoodie cost $138. The price jumped to $168 last year because of changes in American Giant’s supply chain, the biggest of which was the closing of its key supplier, Carolina Cotton Works, in May 2024. The good news is that there’s no additional price hike for the new hoodie. It’s still $168, and it’s available today.
The original hoodie is currently our staff favorite and occupies the rank of “best overall” in WIRED’s Best Hoodies guide. We’ll test out the new one and see if it can keep that top slot.
Global retail is headed for a robust 2025 holiday season, with Salesforce projecting record November–December digital sales of $1.25 trillion, a 4 per cent year-over-year (YoY) rise. US digital sales are forecast to hit $288 billion, up 2 per cent. The growth is strongly tied to the rapid adoption of AI and agent-driven shopping journeys, which are expected to contribute $263 billion in global holiday orders — 21 per cent of total sales.
Salesforce’s analysis, based on data from 1.5 billion global shoppers across Commerce Cloud, Marketing Cloud, Service Cloud, and Agentforce, shows AI-driven and agent-referred traffic is transforming how consumers shop.
AI-assisted traffic jumped 119 per cent YoY in H1 2025, with conversion rates more than 700 per cent higher than social media traffic and 200 per cent higher than traditional channels like search and direct, Salesforce said in a release.
Salesforce projects record $1.25 trillion global digital holiday sales with AI driving $263 billion of orders.
AI traffic surged 119 per cent YoY with 700 per cent higher conversions than social media.
Resale market to hit $64 billion, 77 per cent shoppers to wait for Cyber Week.
Gen Z to spend 3x more in stores.
Retailers urged to adopt AI-first, optimise for generative search, and streamline support.
AI tools are increasingly being used for product discovery, with 17 per cent of consumers using AI assistants or LLMs for searches in the past year, and trust in these recommendations surging to 86 per cent from 46 per cent in May. Retailers are being urged to embrace generative engine optimisation (GEO) — or AI optimisation (AIO) — to ensure product listings and promotions are discoverable in AI-driven search results.
Salesforce highlights thriftiness and sustainability as major drivers this season, with $64 billion in holiday sales projected from the resale market. Forty-six per cent of consumers plan to gift second-hand items, mainly to save money amid trade and tariff uncertainty. Seventy-seven per cent of shoppers are expected to hold off on major purchases until Cyber Week, reinforcing its importance.
Despite surging digital sales, physical retail remains crucial, especially for Gen Z. Three in four Gen Z shoppers plan to shop in stores, and for every $1 they spend online, they are projected to spend $3 in physical stores. Retailers are being encouraged to create seamless omnichannel experiences to capture this generation both online and offline.
Retailers are likely to scale back discounts, with 2 per cent fewer orders expected to include promo codes due to rising supply chain costs. Meanwhile, AI-powered customer service is set to grow 39 per cent this season, helping reduce routine interactions and driving a 2.5 per cent decline in overall service cases. This will free human agents to focus on more complex issues.
Salesforce advises retailers to adopt an AI-first mindset to capture their share of the forecast growth. Integrating AI across product discovery, promotions, and customer support will be key to maximising conversion rates and enhancing the shopping journey from browsing to checkout.
To mark the end of 2025, I was going to write about the amazing work of Francesca Bria and her colleagues who have created the fascinating and very informative website The authoritarian stack – How tech billionaires are building a post-democratic America and why Europe is next. The site outlines five domains of privatised sovereignty – data, defence, space, energy and money. In other words, the foundations of democratic power.
Bria suggests these domains “form the architecture of privatised sovereignty – a technological regime where power flows through laws, infrastructure and automated platforms”.
I was going to follow my analysis of The authoritarian stack with a counter-proposal referencing Bria and her colleagues on an alternative view of what the future could hold – titled, A European alternative for digital sovereignty.
According to Martin Hullin,director of the digitalisation and the common good programme at German non-profit foundation Bertelsmann Stiftung, this report maps a way forward, “Recognising that complete self-sufficiency is neither feasible nor desirable, the initiative calls instead for a shared effort to bolster strategic capabilities and cultivate beneficial international partnerships. It also seeks to demonstrate that digital sovereignty is not about isolation but about advancing a shared vision of the common good”.
Hullin invites us to “consider how this mapping and its recommendations can help spark innovations that are both competitive and compassionate… to build a future in which digitalisation serves not as a source of division but as a force for the common good.”
A way out of the mess
These are very important things. They are things you need to understand. They shine a light on a positive and meaningful way out of the mess we are in. They are things you should definitely read if you want to know what’s really going on in the world.
Imagine that – people somehow raising a newborn child without ChatGPT?
As a human who has actually had a baby, I can reassure all you anxious readers that not only has it been possible for us to do this, we’ve been doing it for centuries without the help of Sam Altman and ChatGPT.
Obviously before ChatGPT we understood that it takes “a village to raise a child” – our families, friends, communities, neighbours, teachers, civil society and amazingly our own innate instincts as well, or what we generally call “parents”. Now thank God all we will need is ChatGPT – how amazingly efficient. Er – thanks so much, Sam?
Incredibly Altman makes this statement while at the same time being comfortable with the contradictory statement he made in an earlier OpenAI podcast suggesting that people “have a very high degree of trust in ChatGPT, which is interesting because, like, AI hallucinates. It should be the tech that you don’t trust that much”.
So which is it Mr Altman? Should I trust something as important as raising my baby to you or not?
Of course, of note and utterly predictable is the help Altman actually asked ChatGPT for in relation to his baby. Turns out it’s all about competitive advantage. He met another tech bro at a party who had a child the same age as his own. His colleague mentioned that his child was crawling at six months. Altman’s, on the other hand, was not.
When the AI bubble bursts – and it will – it will take us all with it. That’s not a future I’d wish for any child and it’s why we should be more worried about the impact of ChatGPT on our children than its ability to raise them
Fuelled with anxiety and envy at such extraordinary baby prowess, Altman raced home to ask ChatGPT if something was wrong and whether he should take his six-month old to the doctor to check his progress.
Here is what his machine told him: “Of course it’s normal, of course you don’t need to go to the doctor. You know parents do all these sorts of things. And, by the way, this is personalised – ChatGPT gets to know you. And, you know, you’re the CEO of OpenAI. You probably are around all these high-achieving people. Maybe you don’t want to project that onto your kid? And you should maybe just relax and he’ll be fine.”
A bro reassurance machine
Yup – that’s exactly the kind of reassurance I’d have been looking for when I was knee deep in nappies and formula. I’d really want to have been reassured that I’m doing fine ranking against my high-achieving colleagues, because really that’s what was top of my mind when I was a sleep-deprived, exhausted new mum trying to figure out how to get a buggy and all those baby supplies into the car on my own. Not to mention how would I push a shopping trolley around while also simultaneously managing the buggy? Clearly ChatGPT is more of a bro reassurance machine than Baby and child could ever have been.
But the most interesting thing about the Jimmy Kimmel interview was the audience reaction. As Altman makes his ridiculous statement, there is a ripple of quiet laughter, as if they are saying, “He is surely not claiming that ChatGPT can raise a child?” Then the laughter deepens as the audience begins to understand the ludicrous nature of that statement and that Altman actually believes it.
It’s a sound I’m hoping to hear lots more of in 2026 – the sound of venture capitalists, angel investors, technology journalists, mainstream journalists and responsible governments calling out the madness of the last three years and the insane claims from the broligarchy about the impact of AI.
It’s the sound of tech leaders taking responsibility for their impact on society, politics, democracy, our planet, our futures. Because when the AI bubble bursts – and it will – it will take us all with it. That’s not a future I’d wish for any child and it’s why we should be more worried about the impact of ChatGPT on our children than its ability to raise them. What it’s going to do to their future should be keeping us awake at night.
So here’s to a market correction in 2026 – and not only a market correction but one where we return to placing our trust for a brighter and sustainable future in the village that has served us so well for centuries, rather than the crazed and destructive visions of those underpinning The authoritarian stack. Surely our children deserve a more enlightened stewardship than that offered by AI?
My Christmas wish is that we have the wisdom to understand what AI can and cannot do – where it is useful and where it is destructive – so that we can protect our children from doomscrolling through the world under the stewardship of men whose political and doctrinal influences range from national conservatism, techno accelerationism, crypto-sovereignty, online radicalisation and tech militarism. It’s all there in the Stack, so you could read that or you could just gather your children close this Christmas and start thinking about and working towards a better vision for the world in 2026 for our deeply human children most of all.