Archive for the ‘materials’ category: Page 190

Jan 24, 2020

Computer model shows ancient Earth with an atmosphere 70 percent carbon dioxide

Posted by in categories: computing, materials

A team of researchers from the University of Washington has found evidence that the Earth’s atmosphere approximately 2.7 billion years ago might have been up to 70 percent carbon dioxide. In their paper published in the journal Science Advances, the group describes their study of micrometeorites and what they learned from them.

As scientists continue to study Earth’s past, they look for evidence of what environmental conditions might have been like in hopes of understanding how life arose. One important piece of the puzzle is the atmosphere. Scientists suspect that its ingredients were far different billions of years ago, but they have little in the way of evidence to prove it. In this new endeavor, the researchers looked to micrometeorites as a possible source of clues. Their thinking was that any material from space that made its way to the surface of the planet had to travel first through the atmosphere—and any material that travels through the atmosphere is highly influenced by its materials, largely due to the high temperatures of atmospheric entry.

Several years ago, researchers found a host of micrometeorites that had landed on Earth approximately 2.7 billion years ago, putting them squarely in the Archean Eon—the time during which it is believed life first appeared on Earth. Study of the micrometeorites showed that they contained high levels of iron along with wüstite. Wüstite forms when iron is exposed to oxygen, but not on the Earth’s surface. It must have been created as the grain-sized meteorites burned and fell through the Earth’s atmosphere. Intrigued by the finding, the researchers created a to simulate the conditions that would lead to the creation of materials such as wüstite on a rock falling through the atmosphere.

Jan 23, 2020

Trinitite: Trinitite

Posted by in categories: materials, military

, also known as atomsite or Alamogordo glass,[2] is the glassy residue left on the desert floor after the plutonium-based Trinity nuclear bomb test on July 16, 1945, near Alamogordo, New Mexico. The glass is primarily composed of arkosic sand composed of quartz grains and feldspar (both microcline and smaller amount of plagioclase with small amount of calcite, hornblende and augite in a matrix of sandy clay)[3] that was melted by the atomic blast. It is usually a light green, although color can vary. It is mildly radioactive but safe to handle.[4][5][6]

In the late 1940s and early 1950s, samples were gathered and sold to mineral collectors as a novelty. Traces of the material may still be found at the Trinity Site as of 2019, although most of it was bulldozed and buried by the United States Atomic Energy Commission in 1953.[7] It is now illegal to take the remaining material from the site; however, material that was taken prior to this prohibition is still in the hands of collectors.

Jan 23, 2020

A Mini Farm That Produces Food From Plastic-Eating Mushrooms

Posted by in categories: materials, sustainability

Circa 2014

According to one recent study, there’s at least 5 trillion pieces of plastic in the ocean. That’s more than 250 tons. So what to do with mountains of plastic waste with nowhere to go? Katharina Unger thinks we should eat it.

The Austrian designer partnered with Julia Kaisinger and Utrecht University to develop a system that cultivates edible plastic-digesting fungi. That’s right, you can eat mushrooms that eat plastic. In 2012, researchers at Yale University discovered a variety of mushroom (Pestalotiopsis microspora) that is capable of breaking down polyurethane. It kicked off a craze of research exploring how various forms of fungi can degrade plastic without retaining the toxicity of the material. The findings got Unger thinking: What if we could turn an environmental problem (waste) into an environmental solution (food)?

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Jan 22, 2020

Engineers develop recipe to dramatically strengthen body armor

Posted by in categories: materials, weapons

According to ancient lore, Genghis Khan instructed his horsemen to wear silk vests underneath their armor to better protect themselves against an onslaught of arrows during battle. Since the time of Khan, body armor has significantly evolved—silk has given way to ultra-hard materials that act like impenetrable walls against most ammunition. However, even this armor can fail, particularly if it is hit by high-speed ammunition or other fast-moving objects.

Researchers at Texas A&M University have formulated a new recipe that can prevent weaknesses in modern-day armor. By adding a tiny amount of the element silicon to , a material commonly used for making , they discovered that bullet-resistant gear could be made substantially more resilient to high-speed impacts.

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Jan 21, 2020

We Might Actually Be Able To Make Star Trek’s Photon Torpedoes

Posted by in categories: materials, military

Circa 2016

A team from the University of Leicester have examined the likely materials that would go into building Star Trek’s photon torpedoes, and they find that it might just be possible to create the tech.

Jan 21, 2020

ESA opens oxygen plant, making air out of moondust

Posted by in categories: materials, space

ESA’s technical heart has begun to produce oxygen out of simulated moondust.

A prototype plant has been set up in the Materials and Electrical Components Laboratory of the European Space Research and Technology Centre, ESTEC, based in Noordwijk in the Netherlands.

“Having our own facility allows us to focus on , measuring it with a mass spectrometer as it is extracted from the regolith simulant,” comments Beth Lomax of the University of Glasgow, whose Ph.D. work is being supported through ESA’s Networking and Partnering Initiative, harnessing advanced academic research for space applications.

Jan 18, 2020

Material developed which is heat-insulating and heat-conducting at the same time

Posted by in categories: computing, materials

Styrofoam or copper—both materials have very different properties with regard to their ability to conduct heat. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz and the University of Bayreuth have now jointly developed and characterized a novel, extremely thin and transparent material that has different thermal conduction properties depending on the direction. While it can conduct heat extremely well in one direction, it shows good thermal insulation in the other direction.

Thermal insulation and thermal conduction play a crucial role in our everyday lives—from computer processors, where it is important to dissipate heat as quickly as possible, to houses, where good insulation is essential for energy costs. Often extremely light, such as polystyrene are used for insulation, while heavy such as metals are used for heat dissipation. A newly developed material, which scientists at the MPI-P have jointly developed and characterized with the University of Bayreuth, can now combine both properties.

The material consists of alternating layers of wafer-thin glass plates between which individual polymer chains are inserted. “In principle, our material produced in this way corresponds to the principle of double glazing,” says Markus Retsch, Professor at the University of Bayreuth. “It only shows the difference that we not only have two layers, but hundreds.”

Jan 17, 2020

Study finds billions of quantum entangled electrons in ‘strange metal’

Posted by in categories: materials, quantum physics

In a new study, U.S. and Austrian physicists have observed quantum entanglement among “billions of billions” of flowing electrons in a quantum critical material.

The research, which appears this week in Science, examined the electronic and magnetic behavior of a “strange metal” compound of ytterbium, rhodium and silicon as it both neared and passed through a critical transition at the boundary between two well-studied quantum phases.

The study at Rice University and Vienna University of Technology (TU Wien) provides the strongest direct evidence to date of entanglement’s role in bringing about quantum criticality, said study co-author Qimiao Si of Rice.

Jan 15, 2020

Researchers gain control over internal structure of self-assembled composite materials

Posted by in category: materials

Composites made from self-assembling inorganic materials are valued for their unique strength and thermal, optical and magnetic properties. However, because self-assembly can be difficult to control, the structures formed can be highly disordered, leading to defects during large-scale production. Researchers at the University of Illinois and the University of Michigan have developed a templating technique that instills greater order and gives rise to new 3D structures in a special class of materials, called eutectics, to form new, high-performance materials.

The findings of the collaborative study are published in the journal Nature.

Eutectic materials contain elements and compounds that have different melting and solidification temperatures. When combined, however, the composite formed has single melting and freezing temperatures—like when salt and water combined to form brine, which freezes at a lower temperature than water or salt alone, the researchers said. When a eutectic liquid solidifies, the individual components separate, forming a cohesive structure—most commonly in a layered form. The fact that eutectic materials self-assemble into composites makes them highly desirable to many modern technologies, ranging from high-performance turbine blades to solder alloys.

Jan 15, 2020

Transparency discovered in crystals with ultrahigh piezoelectricity

Posted by in categories: computing, materials

Use of an AC rather than a DC electric field can improve the piezoelectric response of a crystal. Now, an international team of researchers say that cycles of AC fields also make the internal crystal domains in some materials bigger and the crystal transparent.

“There have been reports that the use of AC fields could significantly improve the piezoelectric responses—for example by 20% to 40%—over DC fields and the improvements have always been attributed to the smaller internal ferroelectric sizes that resulted from the cycles of AC fields,” said Long-Qing Chen, Hamer Professor of Materials Science and Engineering, professor of engineering science and mechanics, and professor of mathematics at Penn State. “About three years ago, Dr. Fei Li, then a research associate at the Materials Research Institute at Penn State, largely confirmed the improvement of piezoelectric performances from application of AC fields. However, it was not clear at all how the internal ferroelectric domains evolved during AC cycles.

”Our group does mostly computer modeling, and more than a year ago we started looking into what happens to the internal domain structures if we apply AC fields to a ferroelectric piezoelectric crystal. We are very curious about how the domain structures evolve during AC cycles. Our and theoretical calculations did show an improved piezoelectric response, but our simulations also demonstrated that the ferroelectric domain sizes actually got bigger during AC cycles rather than smaller as reported in the literature.”