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New analysis suggests wind, not water, formed mound on Mars

By Guest PostMay 9, 2013Sciencealaska, california, caltech, claire newman, clay, dawn sumner, dusty atmosphere, dynamic, earth like, edwin kite, evidence, gale crater, geology, habitability, hirise camera, institute of technology, kevin lewis, lakebed silt, layer, mars rover curiosity, mars science laboratory, martian climate, martian climate history, martian mound, martian surface, models, mount sharp, mt mckinley, NASA, organic compounds, princeton university, red planet, sediment, sedimentary mounds, sedimentary records, slope winds, soil analyses, steep topographic slopes, topographical details, understanding mars past, water molecules, wind deposition

A roughly 3.5-mile high Martian mound that scientists suspect preserves evidence of a massive lake might actually have formed as a result of the Red Planet’s famously dusty atmosphere, an analysis of the mound’s features suggests. If correct, the research could dilute expectations that the mound holds evidence of a large body of water, which would have important implications for understanding Mars’ past habitability.

Researchers based at Princeton University and the California Institute of Technology suggest that the mound, known as Mount Sharp, most likely emerged as strong winds carried dust and sand into the 96-mile-wide crater in which the mound sits. They report in the journal Geology that air likely rises out of the massive Gale Crater when the Martian surface warms during the day, then sweeps back down its steep walls at night. Though strong along the Gale Crater walls, these “slope winds” would have died down at the crater’s center where the fine dust in the air settled and accumulated to eventually form Mount Sharp, which is close in size to Alaska’s Mt. McKinley. (more…)

Space-Age Ceramics Get Their Toughest Test:

By Guest PostDecember 14, 2012Science3d imaging, abdel haboub, alastair macdowell, als beamline, bend magnet, berkeley lab, brian cox, ceramic composites, clay, ct scanning, david marshall, dilworth parkinson, Environment, failure envelope, fracture, function, gas turbine engine, hrishikesh bale, hypersonic jet, internal damage, james nasiatka, mechanical failure, mechanical properties, microcrack, microtomography, operational temperature, real time analysis, risk, robert ritchie, tesla superconducting, ultrahigh, ultraviolet light beams

Berkeley Lab Researchers Develop Real-Time CT-Scan Test Rig For Ceramic Composites at Ultrahigh Temperatures

Advanced ceramic composites can withstand the ultrahigh operational temperatures projected for hypersonic jet and next generation gas turbine engines, but real-time analysis of the mechanical properties of these space-age materials at ultrahigh temperatures has been a challenge – until now. Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed the first testing facility that enables CT-scanning of ceramic composites under controlled loads at ultrahigh temperatures and in real-time.

Working at Berkeley Lab’s Advanced Light Source (ALS), a premier source of X-ray and ultraviolet light beams, the scientists created a mechanical testing rig for performing X-ray computed microtomography that reveals the growth of microcrack damage under loads at temperatures up to 1,750 degrees Celsius. This allows engineers to compute a ceramic composite material’s risk of structural or mechanical failure under extreme operating conditions, which in turn should enable the material’s performance and safety to be improved. (more…)

Diamonds and Dust for Better Cement

By Guest PostDecember 15, 2011Scienceadvanced light source, als, atomic scale structure, baking limestone, basic materials, beam of x rays, bulk modulus, c s h, calcium carbonate, calcium ions, calcium silicate hydrate, calipso, carbon dioxide, clay, clinker, CO2 emissions, diamonds, diffraction patterns, durability of concrete, human activity, hydrostatic pressure, mineral tobermorite, models, nanoscale, paulo monteiro, performance of cement, portland cement, practical alternatives, pressure, quaint village, scottish isle of mull, silicates, simon clark, southern california, stiffness, structure, surface of earth, university of california at berkeley, versatile concrete, water molecules

Structural studies at Berkeley Lab’s Advanced Light Source could point to reduced carbon emissions and stronger cements

It’s no surprise that humans the world over use more water, by volume, than any other material. But in second place, at over 17 billion tons consumed each year, comes concrete made with Portland cement. Portland cement provides the essential binder for strong, versatile concrete; its basic materials are found in many places around the globe; and, at about $100 a ton, it’s relatively cheap. Making it, however, releases massive amounts of carbon dioxide, accounting for more than five percent of the total CO₂ emissions from human activity.

“Portland cement is the most important building material in the world,” says Paulo Monteiro, a professor of civil and environmental engineering at the University of California at Berkeley, “but if we are going to find ways to use it more efficiently – or just as important, search for practical alternatives – we need a full understanding of its structure on the nanoscale.” To this end Monteiro has teamed with researchers at the U.S. Department of Energy’s Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory. (more…)

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New analysis suggests wind, not water, formed mound on Mars

Space-Age Ceramics Get Their Toughest Test:

Diamonds and Dust for Better Cement