Exclusive: When Israel launched a covert scheme to steal material and secrets to build a nuclear bomb, U.S. officials looked the other way and obstructed investigations, as described in a book reviewed by James DiEugenio.
By James DiEugenio
In 1968, CIA Director Richard Helms was presented with a disturbing National Intelligence Estimate (NIE) stating that Israel had obtained atomic weapons, a dangerous development that occurred earlier than the CIA had anticipated.
Spider silk is well-known for its unusual combination of being both lightweight and extremely strong—in some cases, stronger than steel. Due to these properties, researchers have been developing spider-silk-inspired materials for potential applications such as durable yet lightweight clothing, bullet-proof vests, and parachutes.
But so far, the acoustic properties of spider webs have not yet been explored. Now in a new study, a team of researchers from Italy, France and the UK has designed an acoustic metamaterial (which is a material made of periodically repeating structures) influenced by the intricate spider web architecture of the golden silk orb-weaver, also called the Nephila spider.
“There has been much work in the field of metamaterials in recent years to find the most efficient configurations for wave attenuation and manipulation,” coauthor Federico Bosia, a physicist at the University of Torino in Italy, told Phys.org. “We have found that the spider web architecture, combined with the variable elastic properties of radial and circumferential silk, is capable of attenuating and absorbing vibrations in wide frequency ranges, despite being lightweight.”
My friends at ORN setting records again.
Researchers at the Oak Ridge National Laboratory broke a world record for the largest solid 3D-printed item with its trim-and-drill tool. The item, which is practically the size of a large SUV, took 30 hours to print using carbon fiber and composite plastic materials.
Nice.
DARPA-supported researchers have developed a new approach for synthesizing ultrathin materials at room temperature—a breakthrough over industrial approaches that have demanded temperatures of 800 degrees Celsius or more. The advance opens a path to creating a host of previously unattainable thin-film microelectronics, whose production by conventional methods has been impossible because many components lose their critical functions when subjected to high temperatures.
The new method, known as electron-enhanced atomic layer deposition (EE-ALD), was recently developed at the University of Colorado, Boulder (CU) as part of DARPA’s Local Control of Materials Synthesis (LoCo) program. The CU team demonstrated room-temperature deposition of silicon and gallium nitride—linchpin elements in many advanced microelectronics—as well as the ability to controllably etch specific materials, leading to precise spatial control in three dimensions. Such a capability is critical as the demand grows for ever-smaller device architectures.
After first demonstrating the process in early 2015, team members went on to perform detailed mechanistic studies to learn how best to exploit and control EE-ALD for film growth. By controlling the electron energy during the ALD cycles, they discovered that they could tune the process to favor either material deposition or removal. The ability to selectively remove (etch) deposited material with electrons under conditions as low as room temperature is unprecedented and is anticipated to enhance film quality. The group is also exploring other methods to etch specific materials—such as aluminum nitride and hafnium oxide, important in specialized electronics applications—showing that they can selectively etch these materials in composites, which provides an attractive alternative to traditional masking approaches.
A team of Lawrence Livermore National Laboratory researchers has demonstrated the 3D printing of shape-shifting structures that can fold or unfold to reshape themselves when exposed to heat or electricity. The micro-architected structures were fabricated from a conductive, environmentally responsive polymer ink developed at the Lab.
In an article published recently by the journal Scientific Reports (link is external), Lab scientists and engineers revealed a strategy for creating boxes, spirals and spheres from shape memory polymers (SMPs), bio-based “smart” materials that exhibit shape-changes when resistively heated or when exposed to the appropriate temperature.
Scientists have managed to develop a novel method to grow stable, ultra-long 1D carbon chains of a material that is twice as strong as carbon nanotubes and far stronger than diamonds.
Elemental carbon is extremely versatile, and scientists have long been able to create new carbon allotropes that make for super durable and multi-functioning materials—such as everyone’s favorite material, graphene.
The “carbon family” is one very resourceful family. But even with all these developments, carbyne remained elusive. In fact, it is the only form of carbon that has not been synthesized, even though researchers have been studying its properties for over 50 years.
Meet the punk rock version of Device making via Q-Dots.
A wide range of materials can now be synthesized into semiconducting quantum dots. Because these materials grow from solutions, there is scope to combine quantum dots into devices by using simple, low-cost manufacturing processes. Kagan et al. review recent progress in tailoring and combining quantum dots to build electronic and optoelectronic devices. Because it is possible to tune the size, shape, and connectivity of each of the quantum dots, there is potential for fabricating electronic materials with properties that are not available in traditional bulk semiconductors.
Science, this issue p. [885][1]
[1]: http://www.sciencemag.org/content/353/6302/885.full
Scientists in Singapore have created a new type of concrete that bends, but is more durable and sustainable than the typical concrete.
Scientists at Nanyang Technological University (NTU)-JTC Industrial Infrastructure Innovation Center have created a new type of concrete that is flexible and more durable than regular concrete. They call it ConFlexPave.
According to its inventors, ConFlexPave can greatly reduce the weight and thickness of precast pavement slabs, making them lighter and easier to transport and install — thus, halving the time needed for road work and new pavement. Also, because it is more sustainable, it requires less maintenance compared to conventional concrete.
