Earth

The challenge of making concrete greener—reducing its sizable carbon footprint without compromising performance—is just like the world's most ubiquitous manufactured material—hard!

But, according to a new report* from the National Institute of Standards and Technology (NIST), the potential engineering performance, energy-efficiency and environmental benefits make it a challenge worth tackling.

WASHINGTON--The first published results from the Alpha Magnetic Spectrometer (AMS), a major physics experiment operating on the International Space Station, were announced today by the AMS collaboration spokesman, Nobel Laureate Samuel Ting. The result is the most precise measurement to date of the ratio of positrons to electrons in cosmic rays. Measurements of this key ratio may eventually provide the world with our first glimpse into dark matter.

Bottom-up synthesis of nanowires through metal-catalyzed vapor phase epitaxy is a very attractive process to generate high-quality nanowires thus providing an additional degree of freedom in design of innovative devices that extend beyond what is achievable with the current technologies. In this nano-fabrication process, nanowires grow through the condensation of atoms released from a molecular vapor (called precursors) at the surface of metallic nano-droplets. Gold is broadly used to form these nano-droplets.

University of Notre Dame researchers have successfully created three-dimensional anatomical models from CT scans using 3-D printing technology, a process that holds promise for medical professionals and their patients. A paper by the researchers, "3D Printing of Preclinical X-ray Computed Tomographic Data Sets," was published in the Journal of Visualized Experiments this week.

A team of researchers at the San Diego Supercomputer Center (SDSC) and the Department of Electronic and Computer Engineering at the University of California, San Diego, has developed a highly scalable computer code that promises to dramatically cut both research times and energy costs in simulating seismic hazards throughout California and elsewhere.

More useful projections of sea level are possible despite substantial uncertainty about the future behavior of massive ice sheets, according to Princeton University researchers.

Jumping silicon atoms are the stars of an atomic scale ballet featured in a new Nature Communications study from the Department of Energy's Oak Ridge National Laboratory.

The ORNL research team documented the atoms' unique behavior by first trapping groups of silicon atoms, known as clusters, in a single-atom-thick sheet of carbon called graphene. The silicon clusters, composed of six atoms, were pinned in place by pores in the graphene sheet, allowing the team to directly image the material with a scanning transmission electron microscope.

The mountain ranges of the North American Cordillera are made up of dozens of distinct crustal blocks. A new study clarifies their mode of origin and identifies a previously unknown oceanic plate that contributed to their assembly.

MADISON — If the sheet of ice covering Greenland were to melt in its entirety tomorrow, global sea levels would rise by 24 feet.

Three million cubic kilometers of ice won't wash into the ocean overnight, but researchers have been tracking increasing melt rates since at least 1979. Last summer, however, the melt was so large that similar events show up in ice core records only once every 150 years or so over the last four millennia.

A huge pool of warm water that stretched out from Indonesia over to Africa and South America four million years ago suggests climate models might be too conservative in forecasting tropical changes.

Present in the Pliocene era, this giant mass of water would have dramatically altered rainfall in the tropics, possibly even removing the monsoon. Its decay and the consequential drying of East Africa may have been a factor in Hominid evolution.

WEST LAFAYETTE, Ind. – A new study shows clean-air regulations have dramatically reduced acid rain in the United States, Europe, Japan and South Korea over the past 30 years, but the opposite is true in fast-growing East Asian megacities, possibly due to lax antipollution rules or lack of enforcement.

As the universe expands, it is continually subjected to energy shifts, or "quantum fluctuations," that send out little pulses of "sound" into the fabric of spacetime. In fact, the universe is thought to have sprung from just such an energy shift.

By introducing individual silicon atom 'defects' using a scanning tunnelling microscope, scientists at the London Centre for Nanotechnology have coupled single atoms to form quantum states.

Published today in Nature Communications, the study demonstrates the viability of engineering atomic-scale quantum states on the surface of silicon – an important step toward the fabrication of devices at the single-atom limit.

AMHERST, Mass. – Geoscientist Michele Cooke and colleagues at the University of Massachusetts Amherst take an uncommon, "Earth is lazy" approach to modeling fault development in the crust that is providing new insights into how faults grow. In particular, they study irregularities along strike-slip faults, the active zones where plates slip past each other such as at the San Andreas Fault of southern California.

A team of researchers at the San Diego Supercomputer Center (SDSC) and the Department of Electronic and Computer Engineering at the University of California, San Diego, has developed a highly scalable computer code that promises to dramatically cut both research times and energy costs in simulating seismic hazards throughout California and elsewhere.