Sentences with phrase «use calcite»

Even though these creatures use calcite, which is less soluble than aragonite, there are already clear signs of physical damage.

In January independent teams at MIT and the University of Birmingham showed how to use calcite (a common crystal) to make paperclip - size objects disappear.

Not exact matches

A patina of calcite coated the fragment, and the researchers used radioactive uranium in the mineral to date the bone to about 55,000 years old.

By using powerful photon beams generated by the Advanced Photon Source (APS), a DOE User Facility located at Argonne, researchers have shown that they can now control the chemical environment and provide nanoscale structural detail while simultaneously imaging the mineral calcite as it is pushed to its extremes.

To see what happens to the calcite when it is destabilized, researchers used a technique called X-ray reflection interface microscopy (XRIM) at the APS.

He then used the concentration of naturally occurring but unstable uranium in the calcite to estimate how much time had passed since the popcorn formed, giving him a minimum age for the art.

Chen's coworker Baile Zhang of Nanyang Technological University in Singapore, as well as John Pendry at Imperial College London, and their coworkers have shown that a compromise of partial visible - light cloaking of macroscopic objects can be attained using blocks of transparent materials such as calcite crystal, in which light propagates at different speeds in different directions.

Over the next 2 years, Aubert used a diamond saw blade to collect 19 samples of calcite popcorn from 14 paintings in seven caves within a 1 - kilometer radius.

Williams looked at the radioactive elements uranium and thorium trapped in these calcite crystals, using them as a kind of clock based on the rate at which uranium decays into thorium.

Even so, the unusual optical properties of the natural crystal calcite have been used to hide centimetre - size objects under red, green and blue light (Physical Review Letters, vol 106, p 033901).

So the team dated various calcite deposits in the cave and used the assortment of animal remains to deduce that the human teeth were probably between 80,000 and 120,000 years old.

Uranium - series uses the decay of uranium and thorium isotopes (238U, 235U and 232Th) in calcites in particular, such as stalactites and stalagmites in caves.

The team used a high concentration of calcium carbonate that naturally forms a crystalline mineral known as calcite.

Acidification increases the corrosiveness of the water and is also driving a decline in the amount of carbonate ion, needed to make aragonite and calcite, two forms of calcium carbonate that many marine organisms use to build their shells and skeletons.

Created using cultured freshwater pearl and turquoise - hued calcite on a polyester waxed cord, this multi-gem necklace is simple and elegant.

The structure was built using Chateau - Landon, a type of travertine stone which reacts with water to secrete calcite, which in effect bleaches the stone and keeps the building a bright, white colour.

Present - day ocean surface waters are supersaturated for the major carbonate mineral forms used by marine organisms, including the more soluble form aragonite (corals, many mollusks) and the less soluble form calcite (coccolithophores, foraminifera, and some mollusks).

At some times of year, acidification has already reached a critical threshold for organisms living on Alaska's continental shelves.145 Certain algae and animals that form shells (such as clams, oysters, and crab) use carbonate minerals (aragonite and calcite) that dissolve below that threshold.

Calcite - A calcium carbonate (limestone) mineral, used by shell - or skeleton - forming, calcifying organisms such as foraminifera, some macroalgae, lobsters, crabs, sea urchins and starfish.

For example: how much of the O - 18 in the CO2 exchanges with O - 16 in the water used to process the calcite.

Aragonite is more sensitive to ocean acidification than calcite, also used by many marine organisms.