Simulation is emerging as a vital tool for controlling the complex physics of metal additive manufacturing, as engineers seek to improve process reliability and reduce defects. Speaking during the 2025 AMUG Conference, Garrett Clyma, a computational fluid dynamics (CFD) engineer at Flow Science, Inc, outlined how melt pool modeling is providing new capabilities to optimize laser processes without the prohibitive costs of physical experimentation. At the heart of the challenge lies the highly localized heating and rapid cooling of metals during AM. Instabilities in the melt pool caused by overheating or underheating result in defects such as porosity, incomplete fusion, and surface irregularities. “Controlling the material behavior in AM is very challenging because of the complexity of all these different interactions of the individual physics,” Clyma explained. FLOW-3D AM, is a multi-physics CFD platform designed to capture these phenomena with high fidelity, enabling engineers to visualize the evolution of melt pool instabilities and preempt defects before committing to costly build experiments. Garrett Clyma from Flow Science. Photo by Michael Petch. Beam Shaping: A Tool for Process Stability Laser beam shaping, an established practice in welding, is gaining ground in AM as a method to tailor the spatial energy distribution of the beam. Rather than relying on the traditional Gaussian profile, beam shaping distributes energy more evenly or selectively across the beam, influencing melt pool behavior and solidification characteristics. Clyma presented the findings of a study conducted by Dr. Mohamed Bayat’s group at the Technical University of Denmark, which used FLOW-3D AM to investigate ring beam profiles applied to single-track titanium alloy builds. Validation against both cross-sectional cuts and in-situ X-ray monitoring demonstrated strong alignment between simulation and experiment, with melt pool dimension errors well under 10 percent. As the team varied the ratio of core-to-ring power while maintaining constant total laser energy, the simulations revealed clear trends. Ring beams produced wider, shallower melt pools, avoiding the deep keyholes characteristic of Gaussian beams. “The ring beam creates a substantially smaller, less deep annular depression zone, which results in a more stable melt pool,” Clyma said. At higher laser powers, however, instabilities resurfaced. Simulations predicted the formation of elongated molten jets and spatter ejection from the melt pool—behaviors that were subsequently confirmed by high-speed X-ray imaging. Simulated and in-situ experimental melt pool profile in Exploring spatial beam shaping in laser powder bed fusion: High-fidelity simulation and in-situ monitoring. Image via Elsevier. Expanding to Arbitrary Beam Shapes Building on these results, Flow Science conducted an internal study exploring both static and dynamically shaped laser beams, including complex profiles such as infinity patterns, spirals, and five-dot arrays. Running on a 10-core desktop machine, individual simulations generally completed in under six hours, while recent parallelization developments have enabled even larger parametric sweeps. The five-dots configuration, for example, concentrated energy at discrete points, producing high penetration depths under keyhole mode conditions but limited effectiveness in conduction mode. “We’re not efficiently heating up the melt pool, but just heating up these single points,” Clyma explained, emphasizing that beam selection must align with the intended mode of operation. Lower maximum melt pool velocities and more uniform temperature distributions observed in spiral and infinity patterns suggested that these shapes could offer better process stability than concentrated beams. Across all cases, metrics such as intensity, temperature, melt pool velocity, and processing rate provided a consistent framework to evaluate trade-offs before moving to physical trials. “Simulation is a very useful tool for helping to make those decisions,” Clyma said, noting that the growing degrees of freedom in laser control require systematic methods to identify promising beam strategies. A visualization of Laser Powder Bed Fusion Simulation. Image via Flow Science. Surface Tension, Optical Effects, and Material Dependence AMUG Conference attendees raised detailed questions about the extent of physics modeled within FLOW-3D AM. Clyma confirmed that key factors such as temperature-dependent surface tension, contact angle, and laser absorptivity are incorporated into simulations. Absorptivity, often lacking in published material datasets, can be adjusted as a tuning parameter when required. Thermo-physical properties are typically sourced from databases such as JMatPro, allowing simulations to reflect the specific behavior of alloys under melt conditions. Accurate modeling of laser reflections and multi-bounce phenomena is also supported. A participant complimented the strong agreement between simulation predictions and experimental observations, particularly in melt pool shape, spatter formation, and transition between conduction and keyhole modes. Practical Trade-offs: Stability Versus Penetration The session concluded with a discussion of how different beam profiles affect not only defect formation but also material properties. While Gaussian beams enable deeper penetration and potentially finer grain structures due to steeper thermal gradients, they also introduce higher risks of spatter and porosity. In contrast, ring beams offer enhanced stability and reduced peak temperatures, but may alter solidification patterns. “It really just depends on your intended goal,” Clyma said. “If you’re able to explore the effects in simulation rather than experimentation, it can be a lot more advantageous.” FLOW-3D AM provides outputs such as temperature gradients and cooling rates, which are primary drivers of microstructural evolution. Although the software does not yet predict mechanical properties directly, these outputs enable users to infer likely outcomes such as grain size, elongation, and impact resistance. Another engineer elaborated that finer, more oriented grains (arising from high gradients and rapid cooling) often correlate with improved mechanical properties. FLOW-3D AM’s cell-level resolution, often at five million elements or finer, allows for detailed local analysis of these solidification dynamics. As simulation capabilities continue to expand, AM engineers now have a powerful toolkit to optimize laser processing strategies, reduce defects, and enhance the performance of printed metal parts: all before pressing “print” on a machine. What 3D Printing Trends are shaping the industry? Subscribe to the 3D Printing Industry newsletter to keep up with the latest 3D printing news. You can also follow us on LinkedIn, and subscribe to the 3D Printing Industry YouTube channel to access more exclusive content. Featured image shows a visualization of Laser Powder Bed Fusion Simulation. Image via Flow Science. Michael Petch Michael Petch is the editor-in-chief at 3DPI and the author of several books on 3D printing. He is a regular keynote speaker at technology conferences where he has delivered presentations such as 3D printing with graphene and ceramics and the use of technology to enhance food security. Michael is most interested in the science behind emerging technology and the accompanying economic and social implications.

Buzz A new spin on Danish design since 1939 By Vipp • April 30, 2025 • Buzz, Buzz: National (Courtesy Vipp) SHARE Born from the original Vipp chair, the Swivel chair is intended for the office and professional conference rooms that require extended seating time. Designed with a swivel base, this chair in motion will prove a flexible seating experience throughout the day. (Courtesy Vipp) The Swivel chair offers a variety of combinations, functionalities, and upholsteries—choose the one that suits your needs at Vipp.com.

ZDNET's key takeaways The Strapsicle silicone straps upgrade the grip options on your Kindle and provide a secure hold to prevent drops. At $21, Strapsicle is an easy and affordable Kindle accessory to make your reading experience even more comfortable. If you prefer more ergonomic grips or don't like the look of straps across the back of your Kindle, an alternative security option may be best. $20.9 at Amazon apr / 2025If you're adventuring on summer travels in the upcoming months, now is the perfect time to grab my favorite Kindle accessory, especially if you're a voracious reader. Let me explain. If you're an avid e-reader like me (or even if you're new to the Kindle world), you probably quickly figured out how uncomfortable it can be to use the e-reader. That's not because my Kindle Paperwhite is bad, but because it's sometimes hard to find the perfect position for optimal reading enjoyment. Kindles do not have built-in support, making reading in bed, at the pool, at the beach, or anywhere a lot more challenging, especially if you like to read lying down or at odd angles. Also: I switched to an e-paper Android phone with a physical keyboard - here's my buying adviceAnd just like it's popular to outfit our smartphones with grips, rings, and other accessories for stability, it's quite en vogue to do the same for our other tech, including Kindles. After one too many times dropping my Kindle Paperwhite onto my face (that thing does, in fact, leave a mark), I finally caved and was seriously in the market for a grip system. During my journey, I encountered some of the usual accessory contenders: traditional grips like PopSockets, cases that convert to stands, and large, clunky holders. But something else caught my eye -- Strapsicle. I stumbled upon them online. Strapsicle is a stability option created for e-readers like the Kindle and Kobo to ensure a comfortable grip when you read, and a secure hold for your Kindle when you're not (you know, like when you fall asleep with the device in your hand). Strapsicles are simple silicone pieces that pop over the corners of your device and create a strap to handle your Kindle securely. So, where had this accessory been all my life? The answer is that Strapsicle has a large cult following of users, many derived from BookTok, but the accessory hasn't quite made it mainstream. But that situation may be about to change. In 2024, the Australian-based brand sealed a $250,000 deal on Shark Tank Australia. Since I initially wrote this review, I've been using Strapsicle on my Kindle for over six months. I now own multiple sets (like the Eggnog and Blush pink sets pictured in this article) and a matching Strapsicle silicone clutch. Here's why I'm a fan for life. The Strapsicle fits most e-readers, creates a secure grip, and adds a layer of protection. The accessory comes in several fun colors, including blush pink (pictured in this article), lilac, sage green, and more. The straps come in four sizes: small, medium, large, and Kindle Oasis, and a handy size chart makes it easy to match the right Strapsicle set with your respective e-reader model.  Holding my Kindle Paperwhite upside down using both Strapsicles as support.  Kayla Solino/ZDNETSince I have the Kindle Paperwhite 6.8-inch 11th Gen model, I purchased the large size. In the box, I received two silicone straps labeled "top left" and "top right," which made it easy to set up my Kindle.You can use both straps simultaneously or choose to only use one strap on your device, depending on your preference. I tested both approaches, and I prefer having both straps on, especially since the silicone corners add some protection, too. Having a Strapsicle allows me to place my hand wherever I want on my Kindle without worrying about security. This feature is why I chose to try this strap model instead of more conventional methods, like a PopSocket, which can only be fastened in one spot. I can flip my Kindle upside down and all around, and it doesn't budge. PopSocket vs. StrapsicleBefore I dive in, let me say that I am not anti-PopSocket. I enjoyed using a PopSocket on my iPhone throughout my teens, but once I began working at ZDNET, it became increasingly impractical to continue using one on my phone. I spent a lot of time testing MagSafe accessories, and it became annoying to change cases every time I tested products. I also didn't love using a PopSocket enough to purchase a newer MagSafe version. All that said, a PopSocket was still my first thought when considering a grip for my Kindle. According to Reddit, PopSockets are widely used by avid readers on their devices. They're an affordable and personable option for adding a grip to your Kindle. I do see the appeal.  Kayla Solino/ZDNETMy biggest concern with adding a PopSocket to my Kindle was its placement. Should I put it in the center? Off to one side? It turns out that some Redditors had the same issues. While some said they preferred a PopSocket for its more ergonomic grip, others agreed that it was pretty annoying to only be able to grip your Kindle from one spot. One Redditor even admitted using two PopSockets on her Kindle to combat this issue. The placement concerns, and other adherence issues (would it stick to my case?), ultimately pushed me away from the PopSocket option and towards trying Strapsicle. Plus, while basic PopSockets are under $12 on Amazon, some more intricate and fun designs cost up to $35, which I think is quite expensive. Other Redditors said that they liked the Strapsicle for its added security, thanks to its silicone corners, customizable placement (which allows you to grip from anywhere on your Kindle), and the fact that it didn't pinch their pinky like PopSockets do for some people. I agree with these individuals. I experience no pinching or cramping in my hands using Strapsicle, even for long reading stints, and I love that I can read securely from anywhere and at any angle without worry. Plus, the Strapsicle is easy to clean and wipe down, and I can remove the accessory without hassle. The Strapsicle, in short, is phenomenal, and I can't believe it cost me just a smidge more than $20 because I would've paid way more for something that brings this kind of functionality.  Only one Strapsicle placed on my Kindle Paperwhite.  Kayla Solino/ZDNETIf I'm being picky (which I am; it's my job), the criss-cross Strapsicle look may not be for everyone. I don't care too much about the back of my Kindle. But if you are into aesthetically pleasing tech, you may want to consider the PopSocket route. The straps could also fit around my case a little better. I have a simple, flexible, clear case on my Kindle Paperwhite, and while the straps fit fine around the corners, they do have a sort of puckering that prevents them from laying completely flush. However, I don't mind because the straps add padding to my Kindle's corners and work so well. Also: I switched to a color E Ink tablet for months, and it beats the ReMarkable in key waysJust keep in mind that there's a chance that the Strapsicle may not fit with your existing case, so you'd need to buy a new one or go without. Strapsicle does sell its own clear case to accompany the straps. ZDNET's buying adviceMy bottom line here: Strapsicle has created lightning in a bottle in a near-monopolized Kindle accessory market. These simple silicone straps are functional, easy to use, and affordable. At $21, a pair of Strapsicles feels like a much better buy than a singular PopSocket, but to each their own.I do not doubt that Strapsicle will probably be on store shelves in the future and become synonymous with the e-reader experience. I have nothing bad to say about this accessory because my face is now protected from my Kindle, which was exactly the problem I needed to solve. Props to Strapsicle, and I hope I can get these straps for my iPad someday.  Why Strapsicle gets an Editors' Choice award Strapsicle is receiving ZDNET's Editors' Choice award for its trailblazing and practical grip solution for popular e-readers, like the Kindle series. Strapsicle grips secure your device to avoid drops and falls, keep your hand comfortable, and allow reading at a wide range of angles. Plus, the accessory is affordable, appropriate for e-reader users of most ages, and comes in various colors and sizes. Sure, you could still get a PopSocket, but I can't stop recommending this Kindle accessory, and I get asked about Strapsicle everywhere I take my Paperwhite. If you have a Kindle, you need Strapsicle.  Show more Featured reviews

We’re now finally in the new stretch of content for 'Gundam GQuuuuuuX', and it’s a mixed bag.

In the world of OLED panels, there are two main types of OLED material: fluorescent and phosphorescent. Historically, fluorescent OLED has been the easiest to work with, but it’s far less efficient than phosphorescent OLED, which is why, for years, the display industry has been trying to develop the technology needed to create a 100% phosphorescent OLED (PHOLED) panel. And while we’re still not quite there, LG Display says it has crossed a major milestone in that journey, by verifying the commercialization of panels that use blue phosphorescent PHOLED material — the first time all three primary OLED colors (red, green, and blue) have been produced from PHOLED material in a format that is viable for mass production. In theory, a 100% PHOLED panel would exhibit 99% efficiency, with almost all of the energy consumed being converted into light, with hardly any heat. LG Display’s PHOLED technology, which is based on a hybrid two-stack Tandem OLED structure, doesn’t quite reach this peak of performance. The company uses fluorescent blue OLED in the lower stack, with blue PHOLED added to the top stack. LG Display The company is only claiming a 15% energy savings over panels that use fluorescent blue OLED, but it’s still tangible proof that PHOLED may one day meet its loft expectations. Recommended Videos LG Display is set to demonstrate its new blue PHOLED panels at SID Display Week 2025 in San Jose, California on May 11. For now, the new panels are intended for small and medium-sized applications like smartphones and tablets. For portable, battery-driven devices, any energy savings — especially in the display, which tends to consume most of the power — is a welcome change. Related The race to commercialize blue PHOLED began in 2023, when Universal Display Corporation (UDC) announced it had successfully created a blue phosphorescent OLED material that could meet the demands of commercial mass production. At the time, no company had officially signed on to work with UDC on the process, but it was widely believed that both Samsung Display and LG Display were considering it. In 2024, LG Display announced that it would begin working with UDC on the project — that was eight months ago. In the short term, the goal will be to proved these new panels deliver the promised benefits. Longer-term, it will be interesting to see if LG Display can develop a tandem panel that uses 100% PHOLED material, and if it can scale the technology up to the size of today’s OLED TVs. At the size of a TV, energy efficiency is less important that heat reduction. An OLED panel that runs cooler can run brighter, and can theoretically maintain that brightness for longer, without aging the OLED material. 100% PHOLED displays could prove just as capable in brightly lit rooms as their QLED counterparts, one of the few areas where QLED technology continues to enjoy an advantage over OLED. Editors’ Recommendations Please enable Javascript to view this content

Jensen Huang said data-center proliferation is essential for skilled jobs as his company pursues U.S. manufacturing plans.

Joel Souza’s film, notorious for the on-set shooting incident that killed cinematographer Halyna Hutchins, proves a generally compelling consideration of the costs of violence.

Under pressure NASA’s Psyche spacecraft hits a speed bump on the way to a metal asteroid “This kind of thing happens and that’s why we build redundancy into our missions." Stephen Clark – Apr 30, 2025 11:18 pm | 2 Engineers and technicians work on deploying and stowing stationary plasma thrusters on NASA's Psyche spacecraft before its launch in 2023. Two plasma engines are visible here mounted to a dual-axis positioning mechanism, which vectors their thrust in space. Some of Psyche's xenon fuel tanks are visible inside the main body of the spacecraft. Credit: NASA Engineers and technicians work on deploying and stowing stationary plasma thrusters on NASA's Psyche spacecraft before its launch in 2023. Two plasma engines are visible here mounted to a dual-axis positioning mechanism, which vectors their thrust in space. Some of Psyche's xenon fuel tanks are visible inside the main body of the spacecraft. Credit: NASA Story text Size Small Standard Large Width * Standard Wide Links Standard Orange * Subscribers only   Learn more NASA's Psyche spacecraft, located nearly 150 million miles from Earth on the way to an unexplored metal asteroid, has stopped firing its engines after detecting a problem in its propulsion system. NASA published an update Tuesday revealing that the robotic spacecraft shut off its plasma thrusters earlier this month. The news wasn't widely shared until Wednesday, when NASA science chief Nicky Fox posted it on X. "Engineers with NASA’s Psyche mission are working to determine what caused a recent decrease in fuel pressure in the spacecraft’s propulsion system," the agency said. The spacecraft detected the drop in pressure April 1 inside the line that feeds xenon fuel to the spacecraft's four plasma thrusters. Sensors aboard the Psyche probe detected a pressure reduction in the xenon fuel line from about 36 pounds per square inch to about 26 psi. "As designed, the orbiter powered off the thrusters in response to the decrease," NASA said. The Psyche spacecraft uses solar electric propulsion, a highly efficient means of maneuvering through space that relies on solar-generated electricity and more than a ton of xenon gas stored in seven 22-gallon (82-liter) tanks. Inside each of the mission's four thrusters, an electromagnetic field ionizes the xenon gas before expelling the ions to produce thrust. These things happen Louise Prockter, director of NASA's planetary science division, said engineers at the Jet Propulsion Laboratory in California are looking into the problem. So far, there's no effect on the Psyche spacecraft's trajectory. Psyche's plasma thrusters can remain unpowered until at least mid-June before the spacecraft would begin to drift off course, according to NASA. Mission managers decided to keep Psyche's engines turned off until they better understand the pressure decrease. If engineers trace the problem to the fuel line itself, NASA has the option of switching to a backup fuel line to resume thrusting. "This kind of thing happens and that’s why we build redundancy into our missions," Prockter said at a meeting of Mars scientists Wednesday. "We don't have any concerns at the moment about it, but we’re obviously keeping tabs on it.” An illustration depicts a NASA spacecraft approaching the metal-rich asteroid Psyche. Though there are no plans to mine Psyche, such asteroids are being eyed for their valuable resources. Credit: NASA/JPL-Caltech/ASU Each electric thruster on Psyche generates just 250 milli-newtons of thrust, roughly equivalent to the weight of three quarters. But they can operate for months at a time, and over the course of a multi-year cruise, these thrusters provide a more efficient means of propulsion than conventional rockets. The plasma thrusters are reshaping the Psyche spacecraft's path toward its destination, a metal-rich asteroid also named Psyche. The spacecraft's four electric engines, known as Hall effect thrusters, were supplied by a Russian company named Fakel. Most of the other components in Psyche's propulsion system—controllers, xenon fuel tanks, propellant lines, and valves—come from other companies or the spacecraft's primary manufacturer, Maxar Space Systems in California. The Psyche mission is heading first for Mars, where the spacecraft will use the planet's gravity next year to slingshot itself into the asteroid belt, setting up for arrival and orbit insertion around the asteroid Psyche in August 2029. Psyche launched in October 2023 aboard a SpaceX Falcon Heavy rocket on the opening leg of a six-year sojourn through the Solar System. The mission's total cost adds up to more than $1.4 billion, including development of the spacecraft and its instruments, the launch, operations, and an experimental laser communications package hitching a ride to deep space with Psyche. Psyche, the asteroid, is the size of Massachusetts and circles the Sun in between the orbits of Mars and Jupiter. No spacecraft has visited Psyche before. Of the approximately 1 million asteroids discovered so far, scientists say only nine have a metal-rich signature like Psyche. The team of scientists who put together the Psyche mission have little idea of what to expect when the spacecraft gets there in 2029. Metallic asteroids like Psyche are a mystery. Most of Psyche's properties are unknown other than estimates of its density and composition. Predictions about the the look of Psyche's craters, cliffs, and color have inspired artists to create a cacophony of illustrations, often showing sharp spikes and grooves alien to rocky worlds. In a little more than five years, assuming NASA gets past Psyche's propulsion problem, scientists will supplant speculation with solid data. Stephen Clark Space Reporter Stephen Clark Space Reporter Stephen Clark is a space reporter at Ars Technica, covering private space companies and the world’s space agencies. Stephen writes about the nexus of technology, science, policy, and business on and off the planet. 2 Comments

Ahmed Zayan/Unsplash Enter the Royal Society in London – the UK’s national academy of science – and you will see a three-word phrase: “nullius in verba“. This motto, held for over 350 years, translates to “take nobody’s word for it”, meaning science cannot simply be taken on trust; it must be backed by evidence. But what is evidence? Here, things become murkier. A claim that the sky is blue requires little to back it up, as anyone who is able to see it for themselves can attest. Start claiming that the sky is purple, however, and you had better come armed with a good explanation for why we have never noticed this before. Another motto, attributed to the astronomer Carl Sagan, sums up this varying scale of proof: “extraordinary claims require extraordinary evidence”. As we report in this issue, some recent high-profile examples have fallen far short of this. The first would be close to Sagan’s heart: last month, astronomers claimed to have found evidence of a gas potentially produced by alien life on a distant exoplanet, but a reanalysis of the data suggests they may not have detected anything at all. Meanwhile, we report strong criticism from the International Union for Conservation of Nature of the claim by biotech firm Colossal that it has “de-extincted” the dire wolf. The job of science, as always, is now to dig deeper in the hope of uncovering the truth Many are excited by these claims and would like them to be true, but, unfortunately, they are not. We take seriously our duty to accurately report strong claims, as demonstrated by our story about a proposal that light doesn’t have wave-particle duality, but is actually solely a quantum particle. This truly is an extraordinary claim, attempting to overturn a century of physics consensus. As we make clear, the evidence supporting the idea is currently lacking – but physicists are intrigued enough to continue investigating. With no clear reason for why the proposal is wrong, the job of science, as always, is now to dig deeper in the hope of uncovering the truth, or, at least, our best approximation of it. Topics:

"I think I understand interest a lot better than him because I've had to really use interest rates," President Donald Trump said of Federal Reserve Chair Jerome Powell. Anna Moneymaker via Getty Images; Drew Angerer via Getty Images 2025-05-01T04:08:17Z Save Saved Read in app This story is available exclusively to Business Insider subscribers. Become an Insider and start reading now. Have an account? President Donald Trump said he is "not a huge fan" of Federal Reserve Chair Jerome Powell. Trump has repeatedly criticized Powell over the Fed's refusal to cut interest rates. Powell recently said Trump's tariffs would result in higher inflation and weaker economic growth. President Donald Trump took another shot at Federal Reserve Chair Jerome Powell on Wednesday."Mortgage rates are actually down slightly, even though I have a guy in the Fed that I'm not a huge fan of. But that's all right, these are minor details. Don't tell him I said that, please," Trump said of Powell during a speech at the White House.Trump was speaking to business leaders, where he thanked them for making investments to manufacture their products in the US. In his speech, Trump repeated his long-standing criticisms of Powell by honing in on Powell's refusal to cut interest rates."He should reduce the interest rates. I think I understand interest a lot better than him because I've had to really use interest rates. We should have interest rates go down," Trump said.Trump nominated Powell to serve as Fed Chair in 2017, during his first term as president.Trump initially praised Powell when announcing his nomination, saying Powell would be a "wise steward of the Federal Reserve," but soon soured on his choice. He has repeatedly called forIn April 2019, Trump wrote on X, then known as Twitter, that Powell was holding back the US stock market by not cutting interest rates.More recently, on April 17, Trump wrote on Truth Social that Powell's "termination cannot come fast enough" after Powell said Trump's sweeping tariffs on the world could result in higher inflation and weaker economic growth."The ECB is expected to cut interest rates for the 7th time, and yet, 'Too Late' Jerome Powell of the Fed, who is always TOO LATE AND WRONG, yesterday issued a report which was another, and typical, complete 'mess!'" Trump wrote in his post.In the same post, Trump said Powell's "termination cannot come fast enough."no intention" of firing Powell.Trump has said several times that he has the authority to remove Powell before Powell's term ends in May 2026. It's unclear if he is able to do so. The law says a president can only remove a Fed official "for cause," such as for misconduct and not over policy disagreements.In November, shortly after Trump won the presidential election, Powell told reporters that Trump could not fire him because it is "not permitted under the law." Powell also said he would not resign as Fed Chair if Trump asked him to.A representative for the Federal Reserve declined to comment on Trump's remarks on Wednesday. The White House did not respond to a request for comment from Business Insider. Recommended video