Sound metal, don't you think?
HRL Laboratories has made a breakthrough in metallurgy with the announcement that researchers at the famous facility have developed a technique for successfully 3D printing high-strength aluminum alloys—including types Al7075 and Al6061—that opens the door to additive manufacturing of engineering-relevant alloys. These alloys are very desirable for aircraft and automobile parts and have been among thousands that were not amenable to additive manufacturing—3D printing—a difficulty that has been solved by the HRL researchers. An added benefit is that their method can be applied to additional alloy families such as high-strength steels and nickel-based superalloys difficult to process currently in additive manufacturing.
“We’re using a 70-year-old nucleation theory to solve a 100-year-old problem with a 21st century machine,” said Hunter Martin, who co-led the team with Brennan Yahata. Both are engineers in the HRL’s Sensors and Materials Laboratory and PhD students at University of California, Santa Barbara studying with Professor Tresa Pollock, a co-author on the study. Their paper 3D printing of high-strength aluminum alloys was published in the September 21, 2017 issue of Nature.
Additive manufacturing of metals typically begins with alloy powders that are applied in thin layers and heated with a laser or other direct heat source to melt and solidify the layers. Normally, if high-strength unweldable aluminum alloys such as Al7075 or AL6061 are used, the resulting parts suffer severe hot cracking—a condition that renders a metal part able to be pulled apart like a flaky biscuit.
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How is it that fertilized chicken eggs manage to resist fracture from the outside, while at the same time, are weak enough to break from the inside during chick hatching? It’s all in the eggshell’s nanostructure, according to a new study led by McGill University scientists.
The findings, reported today in Science Advances, could have important implications for food safety in the agro-industry.
Birds have benefited from millions of years of evolution to make the perfect eggshell, a thin, protective biomineralized chamber for embryonic growth that contains all the nutrients required for the growth of a baby chick. The shell, being not too strong, but also not too weak (being “just right” Goldilocks might say), is resistant to fracture until it’s time for hatching.
But what exactly gives bird eggshells these unique features?
To find out, Marc McKee’s research team in McGill’s Faculty of Dentistry, together with Richard Chromik’s group in Engineering and other colleagues, used new sample-preparation techniques to expose the interior of the eggshells to study their molecular nanostructure and mechanical properties.
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A woman in Nevada dies from a bacterial infection that was resistant to 26 different antibiotics. A U.K. patient contracts a case of multidrug-resistant gonorrhea never seen before. A typhoid superbug kills hundreds in Pakistan. These stories from recent years — and many others — raise fears about the possibility of a post-antibiotic world.
The development of antibiotics in the early 20th century was one of the greatest leaps forward of modern medicine. Suddenly, common illnesses like pneumonia, strep throat and gonorrhea were no longer potential death sentences.
But even in the infancy of antibiotics, it was clear that their misuse and overuse could lead to antibiotic resistance and eventually create untreatable superbugs.
In this video, we explain how antibiotic resistance happens — and what we can do to avoid living in a post-antibiotic world.
Video: NPR
Inspired by the flashing colors of the neon tetra fish, researchers have developed a technique for changing the color of a material by manipulating the orientation of nanostructured columns in the material.
“Neon tetras can control their brightly colored stripes by changing the angle of tiny platelets in their skin,” says Chih-Hao Chang, an associate professor of mechanical and aerospace engineering at North Carolina State University and corresponding author of a paper on the work.
“For this proof-of-concept study, we’ve created a material that demonstrates a similar ability,” says Zhiren Luo, a Ph.D. student at NC State and first author of the paper. “Specifically, we’ve shown that we can shift the material’s color by using a magnetic field to change the orientation of an array of nanocolumns.”
The color-changing material has four layers. A silicon substrate is coated with a polymer that has been embedded with iron oxide nanoparticles. The polymer incorporates a regular array of micron-wide pedestals, making the polymer layer resemble a LEGO® brick. The middle layer is an aqueous solution containing free-floating iron oxide nanoparticles. This solution is held in place by a transparent polymer cover.
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Printing microelectrode arrays on gelatin and other soft materials could pave the way for new medical diagnostics tools
Microelectrodes can be used for direct measurement of electrical signals in the brain or heart. These applications require soft materials, however. With existing methods, attaching electrodes to such materials poses significant challenges. A team at the Technical University of Munich (TUM) has now succeeded in printing electrodes directly onto several soft substrates.
Researchers from TUM and Forschungszentrum Jülich have successfully teamed up to perform inkjet printing onto a gummy bear. This might initially sound like scientists at play – but it may in fact point the way forward to major changes in medical diagnostics. For one thing, it was not an image or logo that Prof. Bernhard Wolfrum’s team deposited on the chewy candy, but rather a microelectrode array. These components, comprised of a large number of electrodes, can detect voltage changes resulting from activity in neurons or muscle cells, for example.
Second, gummy bears have a property that is important when using microelectrode arrays in living cells: they are soft. Microelectrode arrays have been around for a long time. In their original form, they consist of hard materials such as silicon. This results in several disadvantages when they come into contact with living cells. In the laboratory, their hardness affects the shape and organization of the cells, for example. And inside the body, the hard materials can trigger inflammation or the loss of organ functionalities.
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Genes in Space logo. May 9, 2019 Earth’s atmosphere shields life on the ground from cosmic radiation that can damage DNA. Astronauts in space have no such protection, and that puts them at risk. An investigation on the International Space Station examines DNA damage and repair in space in order to help protect the long-term health of space travelers. An organism carries all of its genetic information in its deoxyribonucleic acid or DNA. This blueprint for life takes the form of specific sequences of nitrogen bases: adenine, cytosine, guanine, and thymine, represented by the letters A, C, G and T.
Image above: The miniPCR device, used to make multiple copies of a particular strand of DNA in space. Image Credit: NASA. One type of DNA damage is double strand breaks, essentially a cut across both strands of DNA. Cells repair these breaks almost immediately, but can make errors, inserting or deleting DNA bases and creating mutations. These mutations may result in diseases such as cancer. Genes in Space-6 looks at the specific mechanism cells use to repair double strand breaks in space. The investigation takes cells of the yeast Saccharomyces cerevisiae to the space station, where astronauts cause a specific type of damage to its DNA using a genome editing tool known as CRISPR-Cas9. The astronauts allow the cells to repair this damage, then make many copies of the repaired section using a process called polymerase chain reaction (PCR) with an onboard device, the miniPCR. Another device, MinION, is then used to sequence the repaired section of DNA in those copies. Sequencing shows the exact order of the bases, revealing whether the repair restored the DNA to its original order or made errors. The investigation represents a number of firsts, including the first use of CRISPR-Cas9 genetic editing on the space station and the first time scientists evaluate the entire damage and repair process in space.
Image above: The student team that developed the Genes in Space 6 experiment. From left to right: David Li, Aarthi Vijayakumar, Michelle Sung, and Rebecca Li. Image Credit: Boeing. “The damage actually happens on the space station and the analysis also happens in space,” said one of the investigators from miniPCR Bio, Emily Gleason. “We want to understand if DNA repair methods are different in space than on Earth.” This investigation is part of the Genes in Space program. Founded by miniPCR and Boeing, the program challenges students to come up with DNA experiments in space that involve using the PCR technique and the miniPCR device on the station. Students submit ideas online, and the program chooses five finalists. These finalists are paired with a mentor scientist who helps them turn their idea into a presentation for the ISS Research and Development Conference. A panel of judges selects one proposed experiment to fly to the space station. “We want to inspire students to think like scientists and give them the opportunity for an authentic science experience that doesn’t cost them anything,” says Gleason. More than 550 student teams submitted ideas last year. The Genes in Space-6 investigation student team includes Michelle Sung, Rebecca Li, and Aarthi Vijayakumar at Mounds View High School in Arden Hills, Minnesota, and David Li, now a freshman at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts. Their mentor is Kutay Deniz Atabay at MIT.
Image above: The Genes in Space 6 student team. Image Credit: GENES IN SPACE. Other investigators include Sarah E. Stahl and Sarah Wallace with NASA’s Johnson Space Center Microbiology group in Houston; G. Guy Bushkin, Whitehead Institute for Biomedical Research, Cambridge; Melissa L. Boyer, Teresa K. Tan, Kevin D. Foley, and D. Scott Copeland at Boeing; and Ezequiel Alvarez Saavedra, Gleason, and Sebastian Kraves at Amplyus LLC, in Cambridge. Amplyus is the parent company of miniPCR Bio. “One thing the investigation will tell us is yes, we can do these things in space,” said Gleason. “We expect to see the yeast use the error-free method of repair more frequently, which is what we see on Earth; but we don’t know for sure whether it will be the same or not. Ultimately, we can use this knowledge to help protect astronauts from DNA damage caused by cosmic radiation on long voyages and to enable genome editing in space.” The procedures used in this investigation may have applications for protecting people from radiation and other hazards in remote and harsh locations on Earth as well. Related links: Genes in Space-6: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7893 miniPCR: https://www.minipcr.com/ MinION: https://www.nasa.gov/mission_pages/station/research/news/biomolecule_sequencer Genes in Space program: https://www.genesinspace.org/ Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html Images (mentioned), Text, Credits: NASA/Michael Johnson/JSC/International Space Station Program Science Office/Melissa Gaskill. Greetings, Orbiter.ch Full article
Food for thought
We might won`t need a last supper yet
It`s hunting season!
It’s been a hard month for space telescopes. First we learned that Kepler is running out of fuel, signaling the end of its second life as an exoplanet hunter. Then we got word that the much-anticipated James Webb Space Telescope faces yet another delay.
But there is some good news on the horizon for astronomers, astrophysicists, planetary geologists, and people who just like learning neat things about far-away worlds. It’s TESS—short for the Transiting Exoplanet Survey Satellite. If all goes well, the new telescope will launch on Monday evening aboard a Falcon 9 rocket. It’s a relatively small satellite, but researchers have giant hopes for what it might discover. It has the potential to identify thousands of new planets, hundreds of rocky worlds like Earth, and dozens of planets hanging out in their star’s habitable zone (where liquid water could exist on the surface), all within our own little corner of the galaxy.
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Eye o' Sofia
Our flying observatory, called SOFIA, carries a 100-inch telescope inside a Boeing 747SP aircraft. Scientists onboard study the life cycle of stars, planets (including the atmosphere of Mars and Jupiter), nearby planetary systems, galaxies, black holes and complex molecules in space.
AND on Oct. 5, SOFIA is going on a special flight to chase the shadow of Neptune’s moon Triton as it crosses Earth’s surface!
In case you’re wondering, SOFIA stands for: Stratospheric Observatory for Infrared Astronomy.
Triton is 1,680 miles (2,700 km) across, making it the largest of the 13 moons orbiting Neptune. Unlike most large moons in our solar system, Triton orbits in the opposite direction of Neptune, called a retrograde orbit. This backward orbit leads scientists to believe that Triton formed in an area past Neptune, called the Kuiper Belt, and was pulled into its orbit around Neptune by gravity.
The Voyager 2 spacecraft flew past Neptune and Triton in 1989 and found that Triton’s atmosphere is made up of mostly nitrogen…but it has not been studied in nearly 16 years!
An occultation occurs when an object, like a planet or a moon, passes in front of a star and completely blocks the light from that star. As the object blocks the star’s light, it casts a faint shadow on Earth’s surface.
But unlike an eclipse, these shadows are not usually visible to the naked eye because the star and object are much smaller and not nearly as bright as our sun. Telescopes with special instruments can actually see these shadows and study the star’s light as it passes near and around the object – if they can be in the right place on Earth to catch the shadow.
Scientists have been making advanced observations of Triton and a background star. They’ve calculated exactly where Triton’s faint shadow will fall on Earth! Our SOFIA team has designed a flight path that will put SOFIA (the telescope and aircraft) exactly in the center of the shadow at the precise moment that Triton and the star will align.
This is no easy feat because the shadow is moving at more than 53,000 mph while SOFIA flies at Mach 0.85 (652 mph), so we only have about two minutes to catch the shadow!! But our SOFIA team has previously harnessed the aircraft’s mobility to study Pluto from inside the center of its occultation shadow, and is ready to do it again to study Triton!
From inside the shadow, our team on SOFIA will study the star’s light as it passes around and through Triton’s atmosphere. This allows us to learn more about Triton’s atmosphere, including its temperature, pressure, density and composition!
Our team will use this information to examine if Triton’s atmosphere has changed since our Voyager 2 spacecraft flew past it in 1989. That’s a lot of information from a bit of light inside a shadow! Similar observations of Uranus in 1977, from our previous flying observatory, led to the discovery of rings around that planet!
Ground-based telescopes across the United States and Europe – from Scotland to the Canary Islands – will also be studying Triton’s occultation. Even though most of these telescopes will not be in the center of the shadow, the simultaneous observations, from different locations on Earth, will give us information about how Triton’s atmosphere varies across its latitudes.
This data from across the Earth and from onboard SOFIA will help researchers understand how Triton’s atmosphere is distorted at different locations by its high winds and its strong tides!
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I need some C - H - O - CO late
My friend just sent me this so y'all have to suffer too
Image: Victor Habbick Visions/Science Photo Library
Traditional electronics are made from rigid and brittle materials. However, a new ‘self-healing’ electronic material allows a soft robot to recover its circuits after it is punctured, torn or even slashed with a razor blade.
Made from liquid metal droplets suspended in a flexible silicone elastomer, it is softer than skin and can stretch about twice its length before springing back to its original size.
Soft Robotics & Biologically Inspired Robotics at Carnegie Mellon University. Video: Mouser Electronics
‘The material around the damaged area automatically creates new conductive pathways, which bypass the damage and restore connectivity in the circuit,’ explains first author Carmel Majidi at Carnegie Mellon University in Pittsburgh, Pennsylvania. The rubbery material could be used for wearable computing, electronic textiles, soft field robots or inflatable extra-terrestrial housing.
‘There is a sweet spot for the size of the droplets,’ says Majidi. ‘We had to get the size not so small that they never rupture and form electronic connections, but not so big they would rupture even under light pressure.’
To read the full article, by Anthony King, in C&I, the members’ magazine for SCI, click here.