NoSpotOfGround

Previously, a yield strength of 5,000 pounds per square inch (psi) was enough for concrete to be rated as “high strength,” with the best going up to 10,000 psi. The new UHPC can withstand 40,000 psi or more.

The greater strength is achieved by turning concrete into a composite material with the addition of steel or other fibers. These fibers hold the concrete together and prevent cracks from spreading throughout it, negating the brittleness. “Instead of getting a few large cracks in a concrete panel, you get lots of smaller cracks,” says Barnett. “The fibers give it more fracture energy.”

The study analyzed data from 258 UK Uber drivers over more than 1.5 million trips between 2016 and 2024. This revealed a significant shift when Uber introduced a dynamic pricing algorithm in 2023. Passengers now pay more per trip, but drivers' earnings have declined. Adjusted for inflation, drivers' hourly income fell from over £22 to just over £19 before operating costs, and drivers are spending more unpaid time waiting for rides than before. Uber's commission has risen from around 25% to 29% and in some cases, Uber took over half the value of the fare.

The researchers found an average of around 100 microplastic particles per liter in glass bottles of soft drinks, lemonade, iced tea and beer. That was five to 50 times higher than the rate detected in plastic bottles or metal cans.

"We expected the opposite result," Ph.D. student Iseline Chaib, who conducted the research, told AFP.

"We then noticed that in the glass, the particles emerging from the samples were the same shape, color and polymer composition—so therefore the same plastic—as the paint on the outside of the caps that seal the glass bottles," she said.

The paint on the caps also had "tiny scratches, invisible to the naked eye, probably due to friction between the caps when there were stored," the agency said in a statement.

This could then "release particles onto the surface of the caps," it added.

They use stacked transparent color sensors, like Foveon camera sensors used to.

In numerous experiments, the researchers put the two prototypes, which differ in their readout technology, through their paces. Their results prove the advantages of perovskite: the sensors are more sensitive to light, more precise in color reproduction and can offer a significantly higher resolution than conventional silicon technology.

The fact that each pixel captures all the light also eliminates some of the artifacts of digital photography, such as demosaicing and the moiré effect.

Aagesen singled out the role of the Spanish grid operator REE and certain energy companies she did not name which disconnected their plants "inappropriately... to protect their installations."

She also pointed to "insufficient voltage control capacity" on the system that day, due in part to a programming flaw, stressing that Spain's grid is theoretically robust enough to handle such situations.

Due to these misjudgments "we reached a point of no return with an uncontrollable chain reaction" that could only have been managed if steps had been taken beforehand to absorb the overvoltage problems, she added.

For the past decade, scientists have been trying to get to the bottom of what seemed like a major inconsistency in the universe. The universe expands over time, but how fast it's expanding has seemed to differ depending on whether you looked early in the universe's history or the present day. If true, this would have presented a major problem to the gold-standard model that represents our best understanding of the universe.

But thanks to the new James Webb Space Telescope, scientists from the University of Chicago have been able to take new and better data—suggesting there may be no conflict after all.

A team from MIT and the Woods Hole Oceanographic Institution (WHOI) has developed an image-analysis tool that cuts through the ocean's optical effects and generates images of underwater environments that look as if the water had been drained away, revealing an ocean scene's true colors. The team paired the color-correcting tool with a computational model that converts images of a scene into a three-dimensional underwater "world," that can then be explored virtually.

The researchers have dubbed the new tool SeaSplat, in reference to both its underwater application and a method known as 3D Gaussian splatting (3DGS), which takes images of a scene and stitches them together to generate a complete, three-dimensional representation that can be viewed in detail, from any perspective.

For now, the method requires hefty computing resources in the form of a desktop computer that would be too bulky to carry aboard an underwater robot. Still, SeaSplat could work for tethered operations, where a vehicle, tied to a ship, can explore and take images that can be sent up to a ship's computer.

From this paper:

Data points indicate best performers by year of market introduction.

The magnified plot shows progress in cool white LEDs from 1996 to 2020. For comparison, efficacies of best performers in legacy lighting technologies for 2020 are shown as coloured horizontal lines.

Note the logarithmic scale of the vertical axis on the main plot and the linear scale on the magnified plot.

From this article:

most improvements in the energy efficiency of LEDs were driven by research and development efforts. Surprisingly, however, R&D contributed relatively little to reductions in the cost of the devices, which were instead linked to economies of scale and continuous manufacturing process improvements over time.

Although the theory is promising, the duo point out that they have not yet completed its proof. The theory uses a technical procedure known as renormalization, a mathematical way of dealing with infinities that show up in the calculations.

So far Partanen and Tulkki have shown that this works up to a certain point—for so-called 'first order' terms—but they need to make sure the infinities can be eliminated throughout the entire calculation.

"If renormalization doesn't work for higher order terms, you'll get infinite results. So it's vital to show that this renormalization continues to work," explains Tulkki. "We still have to make a complete proof, but we believe it's very likely we'll succeed."

Why is the spring strengthened in the middle?

It doesn't seem to affect the spring's buckling characteristics.

My speculation is that it's to reduce spring noise. That strengthened region at the middle is where the spring will buckle outwards most, resting against the barely visible side rails on the inside of the case. Instead of just one wobbly contact point it now has three rigid ones as a "skate" to reduce the stick-slip noise when opening and retracting the tip. Is this right?

(The pen is a Mitsubishi Uni-Ball Power Tank, pretty much my favorite model.)

Tesla Cybertruck appears to be facing significant sales challenges. After initial hype faded, and over a million reservations turned out to be as real as unicorns, Tesla is now enabling leasing options and free upgrades to move its inventory of the futuristic pickup truck. The company's recent silence on the Cybertruck, even omitting it from their earnings call, speaks volumes about the situation.

Tesla initially projected sales of 500,000 Cybertrucks annually and established production capacity at the Giga Texas for 250,000 units per year. After working through the initial reservation backlog with fewer than 40,000 deliveries, the automaker is now struggling to sell the remaining vehicles.