A group of physicists from Canada have been growing their own icicles in a lab in the hope of solving a mystery that has, up until now, continued to puzzle scientists.
The presence of characteristic ripples along the surface of icicles, which remarkably have the same wavelength no matter how big the icicle or where in the world it grows, have led to several studies examining exactly how the ripples form.
Morris and Chen found that ripples only became apparent at the remarkably low salinity of the water with 20 mg of salt per litre. This level, in fact, is a considerably lower level of impurity than found in common tap water.
"We even added a non-ionic ingredient to the distilled water to reduce the surface tension of the thin film of water flowing over the icicle, and it didn't produce ripples," said Chen. "Instead, ripples emerge only on icicles grown from water with dissolved ionic impurities."
HOUSTON – (Oct. 9, 2013) – Carbyne will be the strongest of a new class of microscopic materials if and when anyone can make it in bulk.
If they do, they'll find carbyne nanorods or nanoropes have a host of remarkable and useful properties, as described in a new paper by Rice University theoretical physicist Boris Yakobson and his group. The paper appears this week in the American Chemical Society journal ACS Nano.
Alexandria, VA – An important question asked of recent graduates with geoscience majors is why they chose to major in the earth sciences. Recent analysis of over 400 responses from the National Geoscience Student Exit Survey from 71 geoscience departments identified several common answers among the respondents. Of those surveyed, many declared a geoscience major during their formative undergraduate years for a variety of reasons: enjoyment working in the outdoors, a lifelong interest in the subject and desire for career opportunities are among some of the most common.
Ecological and societal disruptions by modern climate change are critically determined by the time frame over which climates shift. Camilo Mora and colleagues in the College of Social Sciences' Department of Geography at the University of Hawaii, Manoa have developed one such time frame.
Researchers have come one step closer to understanding unstable atomic nuclei. A team of researchers from RIKEN, the University of Tokyo and other institutions in Japan and Italy has provided evidence for a new nuclear magic number in the unstable, radioactive calcium isotope 54Ca. In a study published today in the journal Nature, they show that 54Ca is the first known nucleus with 34 neutrons (N) where N = 34 is a magic number.
BUFFALO, N.Y. — Rocky pillars dotting Iceland's Skaelingar valley were projectiles tossed into the fields by warring trolls. That, at least, is the tale that University at Buffalo geologist Tracy Gregg heard from a tour guide and local hiker when she visited the site on two occasions.
But Gregg and a colleague have a new explanation for the presence of the lava formations — this one also unexpected.
New York University chemists have discovered crystal growth complexities, which at first glance appeared to confound 50 years of theory and deepened the mystery of how organic crystals form. But, appearances can be deceiving.
Their findings, which appear in the latest edition of Proceedings of the National Academy of Sciences, have a range of implications -- from the production of pharmaceuticals and new electronic materials to unraveling the pathways for kidney stone formation.
A team of researchers led by University of Arizona assistant professor Vanessa Huxter has made the first detailed observation of how energy travels through diamonds that contain nitrogen-vacancy centers – defects in which two adjacent carbon atoms in the diamond's crystal structure are replaced by a single nitrogen atom and an empty gap.
These "flaws" result in unexpected and attractive properties that have put such diamonds in the spotlight as promising candidates for a variety of technological advances.
Alexandria, VA –Throughout the history of Earth, supercontinents have formed and ocean basins have opened and closed over timescales of 300 million to 500 million years. But scientists haven't found direct evidence of the in-between phase — an ocean basin that was opening, starting instead to close — until now. Thanks to new high-resolution surveys of the seafloor, scientists think they have evidence of that process starting in the Atlantic Ocean off the coast of Portugal. If they are right, this nascent subduction zone could close the Atlantic Ocean — in roughly 200 million years.
Alexandria, VA – Recent analysis of over 400 responses from the National Geoscience Student Exit Survey from 71 geoscience departments identified distinct trends for bachelor's-, master's- and PhD-level participants on quantitative classes and core science courses. Notably, 70% of all participants had taken Calculus I and II; following those courses, there was a significant drop in bachelor's- and master's-level candidates pursuing further mathematics coursework. Meanwhile, PhD candidates listed multiple courses past Calculus II.
The following highlights summarize research papers that have been recently published in Journal of Geophysical Research-Atmospheres (JGR-D), Journal of Geophysical Research-Earth Surface (JGR-F), Journal of Geophysical Research-Oceans (JGR-C), Geophysical Research Letters, and Paleoceanography.
In this release:
Over 80% of the world's ice-free land is at risk of profound ecosystem transformation by 2100, a new study reveals. "Essentially, we would be leaving the world as we know it," says Sebastian Ostberg of the Potsdam Institute for Climate Impact Research, Germany. Ostberg and collaborators studied the critical impacts of climate change on landscapes and have now published their results in Earth System Dynamics, an open access journal of the European Geosciences Union (EGU).
This is shown by complementary studies now published by scientists of the Potsdam Institute for Climate Impact Research (PIK).
HOUSTON – (Oct. 7, 2013) – Atomically thin sheets of hexagonal boron nitride (h-BN) have the handy benefit of protecting what's underneath from oxidizing even at very high temperatures, Rice University researchers have discovered.
One or several layers of the material sometimes called "white graphene" keep materials from oxidizing – or rusting -- up to 1,100 degrees Celsius (2,012 degrees Fahrenheit), and can be made large enough for industrial applications, they said.