2020-01-01 00:00:00 ..
2020-06-30 21:00:33 UTC
2020-07-01 02:02:58 UTC
We always have a place for talented people, visit the Get Involved section on the wiki to see how you can make SoylentNews better.
Arthur T Knackerbracket has found the following story:
"If you want to hide something in solid media, this is different," [professor Guoliang] Huang said. "In solid media, the wave is more complicated than the radar wave because in solid media we not only have a compression wave but we also have a shear wave. In civil engineering, we deal with earthquakes—seismic waves, which have longitudinal and shear waves, and most of the damage is cause by the shear wave."
Huang said there is no natural material that satisfies the long-standing problem of transformation-invariance, wherein non-standard properties are needed after certain transformations. He said the ultimate purpose of his research is to model, design and fabricate materials that will fill in this "behavioral gap." The new class of cloaking or polar materials his team created is composed of a functionally graded lattice embedded in an isotropic continuum background. The layers were 3-D printed and manually assembled.
"We experimentally and numerically investigated the characteristics of the proposed cloak and found very good cloaking performance under both tension and shear loadings," Huang wrote in his paper, one of two research papers Huang and his team had published by the Physical Review of Letters on the subject of polar materials.
[...] "The results that the University of Missouri team has recently published are encouraging," said Dr. Dan Cole, program manager, Army Research Office, an element of the U.S. Army Combat Capabilities Development Command's Army Research Laboratory. "This research could lead to new strategies for steering mechanical waves away from critical regions in solid objects, which could enable novel capabilities in soldier protection and maneuvers."
Xianchen Xu, Chen Wang, Wan Shou, et al. Physical Realization of Elastic Cloaking with a Polar Material, Physical Review Letters (DOI: 10.1103/PhysRevLett.124.114301)
The U.S. Army will experiment using Starlink broadband to move data across military networks. An agreement signed with SpaceX on May 20 gives the Army three years to test out the service.
The Army and SpaceX signed a Cooperative Research and Development Agreement known as a CRADA, an Army source told SpaceNews.
The project will be overseen by the Combat Capabilities Development Command's C5ISR Center based at Aberdeen Proving Ground, Maryland.
CRADAs are commonly used by the military to evaluate technologies and services from the private sector before it commits to buying them. The Army in this case wants to be able to assess the performance of the Starlink low Earth orbit internet service when connected to military systems. The Army will seek answers to key questions such as what ground equipment it will need to use Starlink and how much systems integration work could be required.
Also at Ars Technica.
The upcoming evaluation of SpaceX's Starlink broadband by the U.S. Army will look primarily at the reliability of the service and potential vulnerabilities of the satellites to hostile attacks, a senior Army official said May 27.
[...] "I would view this as exploratory," Gen. John Murray, commander of the U.S. Army Futures Command, told reporters on Wednesday on a Defense Writers Group conference call.
"It's about figuring out what capabilities they can provide, and what vulnerabilities do they have?" said Murray.
The Army Futures Command advises Army leaders on what investments the service should make to modernize weapons and information systems. One of the priorities identified by Futures Command is high capacity, low latency communications for units in the field that need to move large amounts of data.
A space internet service from low Earth orbit like Starlink would be used by the Army to supplement geosynchronous satellite-based and terrestrial communications.
Murray said the Army has signed exploratory agreements with SpaceX and other companies to make sure the product works before it buys it. The Army wants to try it "before we lock ourselves into a multibillion dollar acquisition program," he said.
Research has shown that, while people in their 20s often leave rural communities, a higher percentage of young adults in their 30s choose rural communities, Schmitt-Wilson said. Still, most of the research on migration of young adults to rural communities focuses on "returners," or those choosing to move home to the community they were raised in, she added.
[...] The researchers found that while study participants were candid about challenges associated with life in rural areas of Montana—such as a lack of amenities and geographic and social isolation—they also highlighted a number of benefits.
"Those benefits included the quality of life they experience in their rural communities, including family-centered environments, low cost of living, unconditional support provided by community members, intergenerational friendships, increased sociability and unique opportunities for personal and professional growth available for young adults in rural communities," Schmitt-Wilson said.
If urban centers are in lockdown and their amenities are gone, would young people still choose city life or would places like rural Montana do?
One in three women in Europe inherited the receptor for progesterone from Neandertals – a gene variant associated with increased fertility, fewer bleedings during early pregnancy and fewer miscarriages. This is according to a study published in Molecular Biology and Evolution by researchers at the Max Planck Institute for Evolutionary Anthropology in Germany and Karolinska Institutet in Sweden.
[...] Progesterone is a hormone, which plays an important role in the menstrual cycle and in pregnancy. Analyses of biobank data from more than 450,000 participants – among them 244,000 women – show that almost one in three women in Europe have inherited the progesterone receptor from Neandertals. 29 percent carry one copy of the Neandertal receptor and three percent have two copies.
"The proportion of women who inherited this gene is about ten times greater than for most Neandertal gene variants," says Hugo Zeberg. "These findings suggest that the Neandertal variant of the receptor has a favourable effect on fertility."
Hugo Zeberg, Janet Kelso, Svante Pääbo. Neandertal Progesterone Receptor [open], Molecular Biology and Evolution (DOI: 10.1093/molbev/msaa119)
General Electric has finally found a buyer for its lighting business and will be selling off its last consumer-facing business after more than 120 years of operation.
Boston-based GE said today it would divest the lighting business to Savant Systems, a smart home management company also based in Massachusetts. The companies did not disclose financial terms of the deal, but sources told The Wall Street Journal that the transaction was valued at about $250 million.
Savant specializes in full smart home systems for the luxury market. Acquiring a lighting business directly will allow it to take advantage of vertical integration and take more control over the physical equipment it installs in consumer' homes. Savant will keep the business's operations in Cleveland, where it is currently based, and will receive a long-term license to keep using the GE branding for its products.
The lighting business is GE's oldest segment, dating all the way back to the company's founding through a series of mergers with Thomas Edison's companies in the late 1880s and early 1890s.
SpaceX and OneWeb have asked for US permission to launch tens of thousands of additional satellites into low Earth orbit.
OneWeb's application to launch nearly 48,000 satellites is surprising because the satellite-broadband company filed for bankruptcy in March. OneWeb is highly unlikely to launch a significant percentage of these satellites under its current structure, as the company reportedly "axed most of its staff" when it filed for bankruptcy and says it intends to use bankruptcy proceedings "to pursue a sale of its business in order to maximize the value of the company." Getting FCC approval to launch more satellites could improve the value of OneWeb's assets and give more options to whoever buys the company.
Arthur T Knackerbracket has found the following story:
Two Lawrence Livermore National Laboratory (LLNL) scientists have discovered a new mechanism for ignition of high explosives that explains the unusual detonation properties of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB).
[...] Highly insensitive explosives offer greatly enhanced safety properties over more conventional explosives, but the physical properties responsible for the safety characteristics are not clear. Among explosives, TATB is nearly unique in its safety-energy trade-offs.
Engineering models for shock initiation safety and detonation performance of explosives rely on physics models that center on the formation and growth of hot spots (local regions of elevated temperature that accelerate chemical reactions) thought to govern these responses. However, models for TATB based on the hot spot concept have so far been unable to simultaneously describe both initiation and detonation regimes. This indicates missing physics in the fundamental understanding of what processes drive insensitive high explosives to detonate.
[...] Answering questions regarding the chemical reactivity of shear bands required turning to quantum-based molecular dynamics (QMD) simulation approaches and high performance computing. "The main challenge with QMD is that it can only be applied to small systems, so we developed a multiscale modeling technique to look at the chemistry of shear band and crystal regions in representative volume elements," explained Matt Kroonblawd, lead author on the study.
Through scale bridging with QMD, the team found that disordered material in shear bands becomes chemically activated. The bands are formed in strongly shocked TATB and react 200 times faster than the crystal, which gives a physical explanation for why engineering models required empirical "switching functions" to go between shock initiation and detonation situations.
Matthew P. Kroonblawd, et al. "High Explosive Ignition through Chemically Activated Nanoscale Shear Bands", Physical Review Letters (2020). DOI: 10.1103/PhysRevLett.124.206002
Resembling giant mealworms, superworms (Zophobas atratus) are beetle larvae that are often sold in pet stores as feed for reptiles, fish and birds. In addition to their relatively large size (about 2 inches long), these worms have another superpower: They can degrade polystyrene plastic. Now, researchers reporting in ACS' Environmental Science & Technology have linked this ability to a strain of bacteria that lives in the larvae's gut.
[...] The team placed 50 superworms in a chamber with polystyrene as their only carbon source, and after 21 days, the worms had consumed about 70% of the plastic. The researchers then isolated a strain of Pseudomonas aeruginosa bacteria from the gut of the worms and showed that it that could grow directly on the surface of polystyrene and break it down. Finally, they identified an enzyme from the bacteria, called serine hydrolase, that appeared to be responsible for most of the biodegradation.
Hong Rae Kim et al. Biodegradation of Polystyrene by Pseudomonas sp. Isolated from the Gut of Superworms (Larvae of Zophobas atratus), Environmental Science & Technology (DOI: 10.1021/acs.est.0c01495)
Feed the plastic grocery bags to the worms, then feed the worms to the seagulls.
In the past decade, there has been renewed thinking about human missions to the moon and perhaps even to Mars. Inevitably, terrestrial microorganisms on the bodies of astronauts, spaceships or equipment will come into contact with extraterrestrial environments. Researchers from the Radboudumc describe in an article in Astrobiology that bacteria can survive on an "extraterrestrial diet," which affected their pathogenic potential
[...] For this study, four non-fastidious environment-derived bacterial species with pathogenic features were selected, including Klebsiella pneumoniae and Pseudomonas aeruginosa. To determine whether extraterrestrial survival and growth were possible, the researchers developed a minimal bacterial diet based on nitrogen, phosphorus, sulphur, iron and water to which carbohydrates found in carbonaceous meteorites were added. The four bacterial species were shown to survive and multiply on this minimal diet.
Jorge Domínguez-Andrés et al. Growth on Carbohydrates from Carbonaceous Meteorites Alters the Immunogenicity of Environment-Derived Bacterial Pathogens, Astrobiology (DOI: 10.1089/ast.2019.2173)
The guide to being a hitchhiker in the galaxy says to be a bacterium.
Earlier this year, Antiquity published an article about an ancient mountain pass uncovered on Lendbreen, a melting ice patch in the central mountain range of the Loomseggen Ridge in Norway. This retreating ice patch exposed lichen-free areas of bedrock where artifacts have been found simply lying on the bare ground. The dated artifacts indicate that the mountain pass was used from around AD 300-1500, but that its usage increased around AD 1000 during the Viking Age. This was a time of elevated travel, trade, and urbanization in Northern Europe.
[...] The findings on Lendbreen are varied and contain numerous types of transportation-related items including the remains of sleds, walking sticks, horse-snowshoes, and horse bones. They also contain many everyday items, including a woven tunic and a mitten, textile rags, and a collection of shoes made from hide. Most notably, archaeologists found ruins of a stone shelter near the top of the ice patch, indicating that this was a significant travel route.
Lars Pilø , Espen Finstad, James H. Barrett. Crossing the ice: an Iron Age to medieval mountain pass at Lendbreen, Norway [open], Antiquity (DOI: 10.15184/aqy.2020.2)
Also at: columbia.edu.
Melting glaciers have been a boon for high-elevation archaeology, because artifacts have been well preserved in the ice.
A group of scientists from NUST MISIS developed a ceramic material with the highest melting point among currently known compounds. Due to the unique combination of physical, mechanical and thermal properties, the material is promising for use in the most heat-loaded components of aircraft, such as nose fairings, jet engines and sharp front edges of wings operating at temperatures above 2000 degrees C.
[...] During recent developments, the goal of the scientists was to create a material with the highest melting point and high mechanical properties. The triple hafnium-carbon-nitrogen system, hafnium carbonitride (Hf-C-N), was chosen, as scientists from Brown University (U.S.) previously predicted that hafnium carbonitride would have a high thermal conductivity and resistance to oxidation, as well as the highest melting point among all known compounds (approximately 4200 degrees C).
Using the method of self-propagating high-temperature synthesis,the NUSTMISIS scientists obtained HfC0.5N0.35, (hafnium carbonitride) close to the theoretical composition, with a high hardness of 21.3 GPa, which is even higher than in new promising materials, such as ZrB2/SiC (20.9 GPa) and HfB2/SiC/TaSi2 (18.1 GPa).
V.S. Buinevicha. A.A. Nepapusheva, D.O. Moskovskikha et al. Fabrication of ultra-high-temperature nonstoichiometric hafnium carbonitride via combustion synthesis and spark plasma sintering, Ceramics International (DOI: 10.1016/j.ceramint.2020.03.158)
The material is meant for spaceplanes.
Now, after nearly 25 years of work by chemists at the University of California, Berkeley, those hydrocarbon bonds -- two-thirds of all the chemical bonds in petroleum and plastics -- have fully yielded, opening the door to the synthesis of a large range of novel organic molecules, including drugs based on natural compounds.
"Carbon-hydrogen bonds are usually part of the framework, the inert part of a molecule," said John Hartwig, the Henry Rapoport Chair in Organic Chemistry at UC Berkeley. "It has been a challenge and a holy grail of synthesis to be able to do reactions at these positions because, until now, there has been no reagent or catalyst that will allow you to add anything at the strongest of these bonds."
Hartwig and other researchers had previously shown how to add new chemical groups at C-H bonds that are easier to break, but they could only add them to the strongest positions of simple hydrocarbon chains.
In the May 15 issue of the journal Science, Hartwig and his UC Berkeley colleagues described how to use a newly designed catalyst to add functional chemical groups to the hardest of the carbon-hydrogen bonds to crack: the bonds, typically at the head or tail of a molecule, where a carbon has three attached hydrogen atoms, what's called a methyl group (CH3).
"The primary C-H bonds, the ones on a methyl group at the end of a chain, are the least electron-rich and the strongest," he said. "They tend to be the least reactive of the C-H bonds."
UC Berkeley postdoctoral fellow Raphael Oeschger discovered a new version of a catalyst based on the metal iridium that opens up one of the three C-H bonds at a terminal methyl group and inserts a boron compound, which can be easily replaced with more complex chemical groups. The new catalyst was more than 50 times more efficient than previous catalysts and just as easy to work with.
"We now have the ability to do these types of reactions, which should enable people to rapidly make molecules that they would not have made before," Hartwig said. "I wouldn't say these are molecules that could not have been made before, but people wouldn't make them because it would take too long, too much time and research effort, to make them."
The payoff could be huge. Each year, nearly a billion pounds of hydrocarbons are used by industry to make solvents, refrigerants, fire retardants and other chemicals and are the typical starting point for synthesizing drugs.
Raphael Oeschger, Bo Su, Isaac Yu, Christian Ehinger, Erik Romero, Sam He, John Hartwig. Diverse functionalization of strong alkyl C–H bonds by undirected borylation. Science, 2020; 368 (6492): 736 DOI: 10.1126/science.aba6146
Arthur T Knackerbracket has found the following story:
A major UK government-funded research study suggests particles released from vehicle tyres could be a significant and previously largely unrecorded source of microplastics in the marine environment.
The study is one of the first worldwide to identify tyre particles as a major and additional source of microplastics. Scientists have previously discovered microplastics, originating from microbeads in cosmetics and the degradation of larger items such as carrier bags and plastic bottles, in marine environments globally—from the deep seas to the Arctic.
Following the government's ban on rinse off microbeads, which is one of the toughest in the world, the Defra-funded study [Defra - Dept for the Environment, Food, and Rural Affairs] led by the University of Plymouth now reveals vital new information that will improve our scientific understanding of how tiny particles from tyres, synthetic fibres from clothing and maritime gear also enter the ocean.
[...] The study shows the tyre particles can be transported directly to the ocean through the atmosphere, or carried by rainwater into rivers and sewers, where they can pass through the water treatment process. Researchers estimate this could place around 100million m² of the UK's river network—and more than 50million m² of estuarine and coastal waters—at risk of contamination by tyre particles.
Its findings also highlight some of the optimal places for intervention, for example, that fitting filters to washing machines could be less effective than changing fabric designs to reduce fibre loss, with another study at the University having recently shown that normal wear and tear when wearing clothes is just as significant a source of microplastic pollution as release from laundering.
[...] "What this study also does is provide further evidence of the complex problems posed by microplastic pollution. We have looked at three pathways and shown that all of them are substantive pathways to the environment. As we work to understand their potential distribution and impacts it is important to also work together with industry and policy makers to identify potential solutions which may include changes in behaviour, changes in product design and waste management."
NB: Video feed is live right now. Launch is scheduled for 1.5 hours from the time this story goes live, i.e.the launch has an instantaneous launch of 20:43 UTC or 16:43 EDT. See yesterday's stories about this launch and for a timeline and additional background information:
According to a tweet by Eric Berger (Ars Technica's writer on all things Space and Weather):
Updated: The plan is to press ahead with today's countdown. Significant weather concerns remain, but there's a chance. The crew will suit up, and SpaceX will continue to prepare the Falcon 9 and Crew Dragon for liftoff at 4:33pm ET.
In other words, should the weather prove to be acceptable at the scheduled launch time, they want to be ready to go.
For today's mission, we need to track weather both at the launch site for liftoff, and down range in case of potential emergencies with the rocket during the countdown or after it launches.
[...] For Kennedy Space Center and SpaceX's Launch Complex 39A, there are 12 different criteria near the pad that must be met before a launch can proceed. These include sustained winds of 30mph or below, no anvil thunderstorm clouds within 10 nautical miles, and various rules about clouds.
When the 45th Space Wing at Patrick Air Force Base in Florida provides the official forecast for a launch, it is basing its percentage solely on conditions for a particular rocket and weather at the launch site. This morning's updated forecast for today's launch attempt of SpaceX's Crew Dragon is decent, with a 50 percent chance of "violating weather constraints" at the time of launch.
However, this forecast does not include several other important considerations, most notably ascent abort weather. This is a really big concern today with the formation of Tropical Storm Bertha off the coast of South Carolina and unsettled weather in Dragon's path.
Assuming the weather cooperates, check out any of these live video links:
The combination of racing drivers and esports is turning out to be full of drama. When COVID-19 put a stop to real-world racing in March, professional series moved the action, using sims like iRacing and rFactor 2 along with streaming platforms like Twitch to give drivers something to do and fans something to watch. But the transition hasn't been a smooth one for some of the professional drivers, particularly those who had little interest or experience in the simulation side of things before the pandemic.
Audi's Daniel Abt is the latest to discover that it's not just a game when you're being paid to show up. The latest incident took place on Saturday in Formula E's Race at Home challenge, where the sport's real-world stars show up to compete in rFactor 2 to raise money for UNICEF. Set in a virtual version of Berlin's Tempelhof airport, Abt qualified well and raced to third place, a performance that was in stark contrast to his previous esports races. This, and the fact that he was obscured from view in his video feed, raised suspicions among some of the other drivers.
Those suspicions had merit. When the esports race organizers investigated, they checked IP address data and discovered the presence of a ringer—sim racing professional Lorenz Hoerzing, who raced pretending to be Abt. Disqualified from the race, Abt was ordered to donate $10,817 (€10,000) to charity. (Hoerzing was also stripped of his sixth-place finish in the companion event held for professional sim racers, and banned from competing in that series again.) After admitting he swapped in Hoerzing, Abt apologized in a statement on Sunday.
"I would like to apologize to Formula E, all of the fans, my team and my fellow drivers for having called in outside help during the race on Saturday. I didn't take it as seriously as I should have. I'm especially sorry about this, because I know how much work has gone into this project on the part of the Formula E organization. I am aware that my offense has a bitter aftertaste, but it was never meant with any bad intention. Of course, I accept the disqualification from the race. In addition, I will donate 10,000 Euros to a charitable project," he said.
[...] While these esports sim racers might just be a game to some, racing drivers are professional athletes under contract to big organizations. And when you're being paid to represent a big brand, there are consequences for making it look bad. Unsporting conduct, smoking weed, and even speaking out politically will get you in hot water in professional esports, and although Abt wasn't signed by Audi to play rFactor 2, he was still representing the organization—which bears his family name, no less—on Saturday. At a time when Twitch streams are bringing many racing stars closer to their fans, it seems like a shame that drivers of the caliber of da Costa and Vanthoor are retreating over someone else's mistake.