Tech
Alloys that ‘remember’ their shape can prevent railroad damage
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
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Alloys that ‘remember’ their shape can prevent railroad damage (2025, October 30)
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Tech
The Best Streaming Deals Right Now Are Ad-Free
The Black Friday streaming deals bonanza is over. But holiday streaming deals continue in December, and some of the December deals are better than the one I signed up for in November. Buyer’s remorse is eternal, but this time it’s also reversible.
The best December streaming deals are ad-free. It’s not an eye-poppingly low number, but you can get a 4K-streaming, ad-free bundle of HBO Max, Disney+, and Hulu for $33. That’s more than 40 percent off—or $23 less than list price. But most important: no ads.
In fact, I plan to upgrade to the no-ad bundle. Because it turns out I don’t like ads. No ads means no regret when the climactic scene in an old Homeland episode is abducted by a discount car insurance company, instead of whoever else was supposed to do the abducting. This said, the ad-supported HBO/Disney bundle is also on a 40 percent off deal. And so are a number of other bundles—so many bundles, including an Apple TV/Peacock bundle that’ll let you stream NFC playoff games and the Super Bowl for barely more than the price of Apple TV on its own.
Here’s a quick guide to the best streaming deals and streaming bundles in December 2025. Note that we’re not including every TV streaming offer on the planet, just the ones that are actually good deals at the moment.
Regular Price Without Bundle: $56/month
Tech
Grindr Goes ‘AI-First’ as It Strives to Be an ‘Everything App for the Gay Guy’
Every Grindr user is unique. Italian men love feet. South Koreans prefer open relationships. The highest percentage of self-proclaimed “daddies” call the US home and Switzerland is overrun with twinks. Delivered by annual trend report Grindr Unwrapped, those critical insights offer the type of information that will help usher the company into its “AI-first” era where it’s “the everything app for the gay guy,” CEO George Arison tells WIRED.
Grindr was the first to leverage geo-location tech when it burst onto the scene in 2009. Arison arrived at the company in 2022 from the world of automotive ecommerce. With him at the helm, the company has undergone “a bit of a refounding,” he says, including a major overhaul of staff—85 percent of current 160 US employees were hired in the last three years—and bigger investments in product.
All of his moves, he says, have been about building trust with users. Grindr may indeed be the most popular gay dating and hookup app in the world, but its popularity has only made it a target of controversy, including a 2024 lawsuit that alleged users’ HIV status and testing information was shared with third-party vendors and, in July, criticism for blocking users who posted the phrase “no Zionists” in their profile. Skepticism over Arison’s conservative politics probably hasn’t helped either.
Even so, Arison tells me he is laser focused on the task ahead. One that almost didn’t happen. Controlling stakeholders Raymond Zage and James Lu submitted an offer to take the company private in October. The bid—a buyout that valued the company at $3 billion—came to an anticlimactic end in November when they failed to come up with the money. The acquisition could have potentially derailed Arison’s priorities, but for now, that’s all behind him.
This interview has been edited for clarity and length.
JASON PARHAM: Grindr is now positioning itself as more than a place for hookups. It wants to be a social everything app—why?
GEORGE ARISON: We didn’t really have a mission before 2023. But it was always more than a hookup app because it was being used for so many different things, but no one had said, OK, this is what we want to be. This year is when we really went after the gayborhood vision. Now we are actually building features that intentionally support all these different use cases in which people are engaged in on the app.
Tech
OpenAI Rolls Back ChatGPT’s Model Router System for Most Users
OpenAI has quietly reversed a major change to how hundreds of millions of people use ChatGPT.
On a low-profile blog that tracks product changes, the company said that it rolled back ChatGPT’s model router—an automated system that sends complicated user questions to more advanced “reasoning” models—for users on its Free and $5-a-month Go tiers. Instead, those users will now default to GPT-5.2 Instant, the fastest and cheapest-to-serve version of OpenAI’s new model series. Free and Go users will still be able to access reasoning models, but they will have to select them manually.
The model router launched just four months ago as part of OpenAI’s push to unify the user experience with the debut of GPT-5. The feature analyzes user questions before choosing whether ChatGPT answers them with a fast-responding, cheap-to-serve AI model or a slower, more expensive reasoning AI model. Ideally, the router is supposed to direct users to OpenAI’s smartest AI models exactly when they need them. Previously, users accessed advanced systems through a confusing “model picker” menu; a feature that CEO Sam Altman said the company hates “as much as you do.”
In practice, the router seemed to send many more free users to OpenAI’s advanced reasoning models, which are more expensive for OpenAI to serve. Shortly after its launch, Altman said the router increased usage of reasoning models among free users from less than 1 percent to 7 percent. It was a costly bet aimed at improving ChatGPT’s answers, but the model router was not as widely embraced as OpenAI expected.
One source familiar with the matter tells WIRED that the router negatively affected the company’s daily active users metric. While reasoning models are widely seen as the frontier of AI performance, they can spend minutes working through complex questions at significantly higher computational cost. Most consumers don’t want to wait, even if it means getting a better answer.
Fast-responding AI models continue to dominate in general consumer chatbots, according to Chris Clark, the chief operating officer of AI inference provider OpenRouter. On these platforms, he says, the speed and tone of responses tend to be paramount.
“If somebody types something, and then you have to show thinking dots for 20 seconds, it’s just not very engaging,” says Clark. “For general AI chatbots, you’re competing with Google [Search]. Google has always focused on making Search as fast as possible; they were never like, ‘Gosh, we should get a better answer, but do it slower.’”
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