Proponents say this natural alternative to wildfire cleanup is potentially cheaper.
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Category: materials – Page 279
Metal foam stops .50 caliber rounds as well as steel – at less than half the weight
Researchers have demonstrated that vehicle armor using composite metal foam (CMF) can stop ball and armor-piercing .50 caliber rounds as well as conventional steel armor, even though it weighs less than half as much. The finding means that vehicle designers will be able to develop lighter military vehicles without sacrificing safety, or can improve protection without making vehicles heavier.
CMF is a foam that consists of hollow, metallic spheres—made of materials such as stainless steel or titanium—embedded in a metallic matrix made of steel, titanium, aluminum or other metallic alloys. In this study, the researchers used steel-steel CMF, meaning that both the spheres and the matrix were made of steel.
For the study, researchers manufactured a hard armor system consisting of a ceramic faceplate, a CMF core and a thin back plate made of aluminum. The armor was tested using .50 caliber ball and armor-piercing rounds. The armor was tested with the rounds being fired at impact velocities from 500 meters per second up to 885 meters per second.
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Signs & Symptoms of Bone Marrow Disease
Bone marrow is a soft spongy material that is located inside of the bones. Bone marrow is necessary for the transition that stem cells make to become one of the types of blood cells (red blood cells, platelets or white blood cells). Bone marrow disease occurs when there is some kind of abnormality or interference with the production of blood cells. Leukemia, aplastic anemia and myelodysplastic syndromes (MDS) are three types of bone marrow disorders that affect the production of blood cells and the bone marrow. Symptoms of each type of bone marrow disease will vary according to its severity, but tend to be similar in nature.
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NASA and MIT Debut Shape-Shifting Airplane Wing
A team from NASA and MIT has created a new type of airplane wing — and it could make air travel far more efficient.
In a paper published in the journal Smart Materials and Structures on Monday, the researchers describe how they built an airplane wing from hundreds of identical, lightweight cube-like structures, all bolted together and then covered with a thin polymer material.
The design allows the wing to change shape automatically, adjusting itself to whatever configuration is optimal for the current phase of flight — with one configuration for take-off, for example, and another for landing.
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Civilization: Institutions, Knowledge and the Future — Samo Burja
Our civilization is made up of countless individuals and pieces of material technology, which come together to form institutions and interdependent systems of logistics, development and production. These institutions and systems then store the knowledge required for their own renewal and growth.
We pin the hopes of our common human project on this renewal and growth of the whole civilization. Whether this project is going well is a challenging but vital question to answer.
History shows us we are not safe from institutional collapse. Advances in technology mitigate some aspects, but produce their own risks. Agile institutions that make use of both social and technical knowledge not only mitigate such risks, but promise unprecedented human flourishing.
Watch this video where we investigate this landscape, evaluate our odds, and try to plot a better course.
Samo Burja is a sociologist and the founder of Bismarck Analysis, a firm that analyzes institutions, from governments to companies. His research work focuses on the causes of societal decay and flourishing. He writes on history, epistemology and strategy.
Researchers develop wood that can cool a home
Wood has a series of tiny structures inside that are used to carry water and nutrients to all parts of a living tree. Scientists have now figured out how to harness those same small structures to keep a home cool. Researchers at the University of Maryland and the University of Colorado Boulder say that the material could save 20% in AC bills.
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New superconductivity record edges closer to room temperature
No matter how good a material is at conducting electricity, there’s usually some resistance – unless you use superconductive materials. Since they can conduct electricity with absolutely no loss, they could be revolutionary if not for one little problem: they only work if kept extremely cold. But now researchers at Max Planck have reported a new record high temperature for superconductivity, at a toasty −23° C (−9.4° F).
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Lithium doesn’t crack under pressure, it transforms
Using cutting-edge theoretical calculations performed at NERSC, researchers at Berkeley Lab’s Molecular Foundry have predicted fascinating new properties of lithium—a light alkali metal that has intrigued scientists for two decades with its remarkable diversity of physical states at high pressures.
“Under standard conditions, lithium is a simple metal that forms a textbook crystalline solid. However, scientists have shown that when you put a lithium crystal under pressure, the atomic structure changes and, somewhat counterintuitively, its conductivity drops, becoming less metallic,” said Stephanie Mack, a graduate student research assistant at Berkeley Lab and first author of the study, published in PNAS. “We’ve discovered it also becomes topological, with electronic properties similar to graphene.”
Topological materials are a recently discovered class of solids that display exotic properties, such as having insulating interiors yet highly conductive surfaces, even when deformed. They are exciting for potential applications in next-generation electronics and quantum information science. According to coauthors Sinéad Griffin and Jeff Neaton, lithium becomes topological at high but experimentally achievable pressures, comparable to one-quarter of the pressure at the Earth’s center.
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