Long-time Slashdot reader SpzToid shares a new report from the Economist: Thanks to innovations such as fractal colouration patterns, which mimic nature by repeating shapes at different scales, the distance from which naked eyes can quickly spot soldiers wearing the best camouflage has shrunk, by one reckoning, by a fifth over the past two decades. That is impressive. On today's battlefields, however, it is no longer enough to merely hide from human eyes.

People and kit are given away as well by signals beyond the visual spectrum, and devices that detect these wavelengths are getting better, lighter and cheaper. Thermal sensors are a case in point. Today, one that costs about $1,000 and weighs as little as five sachets of sugar can, in good weather, detect a warm vehicle as far off as 10km. As Hans Kariis, deputy head of signatures research at the Swedish Defence Research Agency, notes, that is well beyond the range at which a small drone would be spotted. Two decades ago, he adds, a less sensitive thermal sensor weighing a kilogram cost ten times as much.
And then there's automatic target-detection software, the article points out, like the Kestrel software deployed in more than 3,500 aircraft around the world, which "scans feeds of visual, infrared and radar data, and places red boxes around people and other potential targets, even as their positions in the frame move." And the threat has only increased with the arrival of satellite-based synthetic-aperture-radar (SAR) imagery.

But then the article lists examples of new camouflage that now tricks electronic sensors:

• Military vehicles affix hexagon-shaped sheets that can be cooled with electricity to blend into the temperature of their surroundings.
• Camouflage netting that absorbs (some) incoming radar beams with semi-conducting polymers while reducing heat signatures with insulation — and reflecting back the cooler temperature of the ground.
• Netherlands-based TNO makes "battery-powered sniper suits" embedded with 500 LEDs that match the luminosity and color of the surroundings using real-time data from a helmet camera.

MIT News has an announcement: The boiling of water or other fluids is an energy-intensive step at the heart of a wide range of industrial processes, including most electricity generating plants, many chemical production systems, and even cooling systems for electronics. Improving the efficiency of systems that heat and evaporate water could significantly reduce their energy use. Now, researchers at MIT have found a way to do just that, with a specially tailored surface treatment for the materials used in these systems. The improved efficiency comes from a combination of three different kinds of surface modifications, at different size scales. The new findings are described in the journal Advanced Materials in a paper by recent MIT graduate Youngsup Song PhD '21, Ford Professor of Engineering Evelyn Wang, and four others at MIT..... "If we have lots of bubbles on the boiling surface, that means boiling is very efficient, but if we have too many bubbles on the surface, they can coalesce together, which can form a vapor film over the boiling surface," Song says. That film introduces resistance to the heat transfer from the hot surface to the water. "If we have vapor in between the surface and water, that prevents the heat transfer efficiency and lowers the critical heat flux value," he says.... Adding a series of microscale cavities, or dents, to a surface is a way of controlling the way bubbles form on that surface, keeping them effectively pinned to the locations of the dents and preventing them from spreading out into a heat-resisting film... In these experiments, the cavities were made in the centers of a series of pillars on the material's surface. These pillars, combined with nanostructures, promote wicking of liquid from the base to their tops, and this enhances the boiling process by providing more surface area exposed to the water. In combination, the three "tiers" of the surface texture — the cavity separation, the posts, and the nanoscale texturing — provide a greatly enhanced efficiency for the boiling process, Song says... The nanostructures promote evaporation under the bubbles, and the capillary action induced by the pillars supplies liquid to the bubble base. That maintains a layer of liquid water between the boiling surface and the bubbles of vapor, which enhances the maximum heat flux.
While the article stresses it's still a laboratory-scale process (needing more work to become a practical "industry-scale" process), "There may be some significant small-scale applications that could use this process in its present form, such as the thermal management of electronic devices, an area that is becoming more important as semiconductor devices get smaller and managing their heat output becomes ever more important." Wang says in the announcement, "There's definitely a space there where this is really important." The article includes a bizarre-looking video showing how water now boils on their specially treated surface.

Thanks to Slashdot reader joshuark for sharing the link!

CNBC reminds us that Ukraine is also home "to a massive community of software developers who work remotely for companies all over the U.S. and Europe.

"There were 200,000 Ukrainian developers in the country in 2020, according to Amsterdam-based software development outsourcing company Daxx, which says that 20% of Fortune 500 companies have their remote development teams in Ukraine." As major cities across Ukraine endure devastating attacks that have seen buildings reduced to rubble, company leaders in the U.S. and Europe have expressed awe at their Ukraine-based staff. Those developers, along with other Ukrainian civilians in the country, are now being forced to defend their homes and cities while sheltering from Russian bombs. But many are still continuing to remotely work for their employers, supporting the local defense effort by day while sending in their deliverables by night.

"Yes our teams are sending deliverables from a f — ing parking garage in Kharkiv under heavy shelling and gunfire in the area. Amazing humans," Logan Bender, chief financial officer at a San Francisco-based software licensing company, said in a story posted to Instagram on Tuesday by venture capital meme account PrayingforExits. "We of course told them all deliverables are off the table. Nothing of you expected other than to let us know how we can help other than wiring money and getting their visa process going," he said. Bender has been working to get a defense service to extract his employees from the conflict zone under armed guards....

"Our lead front-end developer fled to Lviv to his parents' rural house 40km outside the city and is still submitting pull requests," Eric Hovagim, CEO and founder of Los Angeles-based betting platform Pogbet, told CNBC. "He's returning to Lviv tomorrow morning to continue his work while helping with the fight."

"These Ukrainians are built different," Hovagim said. "No armed guard extraction necessary. These people are their own armed guards...."

Ukrainians in IT-related fields are also deploying their skills for the fight at home. Employees at a local digital marketing agency in Kyiv are helping carry out cyberattacks against Russian entities in collaboration with Ukraine's Ministry of Digital Transformation. A local Telegram channel dedicated to crowd-sourcing programmers to carry out cyberattacks against Russia has nearly a million subscribers...

Alexandru Asimionese, co-founder of Moldova-based software developer Labs42, described one of his freelance designers based in the northwestern Ukrainian city of Lutsk. "In the morning goes to buy high-protein snacks to deliver to the local army. Late night, sends logo ideas. Always paid in crypto (via) Binance," he said. Another start-up manager said that his Ukrainian girlfriend was returning to Ukraine from overseas to fight, and plans to continue working for her tech company while not fighting invaders.