Sentences with phrase «calcite as»

Budai, J. M., A. M. Martini, L. M. Walter, and T. C. W. Ku, 2002, Fracture - fill calcite as a record of microbial methanogenesis and fluid migration: a case study from the Devonian Antrim Shale, Michigan basin: Geofluids, v. 2, p. 163183.

In one demonstration of the instrument's capabilities, the researchers scanned a 70 - by -70-micron sample of calcite as it was first immersed in deionized water and later exposed to sulfuric acid.

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.

Not exact matches

But as you descend underground, past Titania's Veil (a gleaming white calcite formation), crossing Giant's Hall and skirting the mirror surface of Dream Lake, you will hear an ethereal music start to fill the dripping hush.

The adapted cultures produced even more new biomass and about twice as many calcite platelets than the control group under the high temperatures.

Then one day in 2011, a Griffith University archaeologist named Adam Brumm noticed that some of the artwork was covered with calcite growths colloquially known as cave popcorn.

As the X-rays pushed the calcite to more extreme levels of instability, researchers were surprised to see that the dissolving pits became distorted and formed ink splatter - like irregularities, indicating that some parts were dissolving quicker than others.

In this case, the microscope not only identified signatures corresponding to calcium carbonate as forming the crust, but was also able to differentiate between the calcite and vaterite forms when it was present as a mixture while still attached to the leaf surface.»

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.

As they form over time, stalagmites develop annual layers of the mineral calcite, which are broadly similar to the rings of a tree.

This would also explain the unusual lack of typical pond fossils at the site, as well as the near lack of gnaw marks on bones and calcite and barite concretions found on bones excavated from the quarry.

Up to now previous investigations focused on calcite or aragonite saturation state as indicators of calcifiers thresholds, which may completely miss the vulnerability of many calcifiers.

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.

The scientists worked with calcite (CaCO3), which has the same composition as chalk and marble and was one of the most abundant minerals in our planet's earliest days.

As expected, the acid dissolved the calcite, leaving nothing but a weakened black sponge full of micropores.

Simulating 1000 voyages between Norway and Greenland with varying cloudiness at summer solstice and spring equinox, we revealed the chance with which Viking sailors could reach Greenland under the varying weather conditions of a 3 - week - long journey as a function of the navigation periodicity Δt if they analysed sky polarization with calcite, cordierite or tourmaline sunstones.

To find out whether acid rain was indeed the problem, the team focused on one problematic sliding layer in the Jiweishan avalanche: a thin bed of black shale, which contains slippery clay minerals such as talc, in addition to fine organic material and calcite, which helps cement the shale together.

Secondary calcite may be precipitated from groundwater and deposited in caves, producing formations such as stalagmites and stalactites.

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.

In this image, researchers observe distortions in the reaction front (the boundary between the blue and red regions) as they form on the surface of the calcite mineral, driven by the high solution acidity where the reaction fronts become unstable.

Beaded waterfall necklace «Elephant Dreams» by Tiraphan Hasub can be found in jewelry categories such as Animal Themed Necklaces, Calcite Necklaces, Turquoise Necklaces, Turquoise Colored Necklaces, Polyester Necklaces, Brass Necklaces and Waterfall Necklaces.

Calcite chips dyed to a turquoise shade are as blue as the sky in a bracelet designed by Tiraphan Hasub.

Elusive as moonlight, pearl's quiet glow nestles beside calcite, quartz and blue resin globes.

Brass beaded bracelet «Verve» by Tiraphan Hasub can be found in jewelry categories such as Birthstone Bracelets, Bohemian Bracelets, Calcite Bracelets, Jasper Bracelets, Polyester Bracelets, Brass Bracelets and Beaded Bracelets.

The Thai artisan crafts the necklace by hand, adding calcite dyed green, as well as silver beads crafted by Karen

Beaded dangle earrings «Blue Honey» by Siriporn can be found in jewelry categories such as Birthstone Earrings, Calcite Earrings, Jasper Earrings, Silver Earrings, Sterling Silver Earrings, Beaded Earrings and Dangle Earrings.

Beaded gemstone bracelet «Flamboyant Feast» by Tiraphan Hasub can be found in jewelry categories such as Birthstone Bracelets, Calcite Bracelets, Quartz Bracelets, Aventurine Bracelets, Carnelian Bracelets, Agate Bracelets, Glass Bead Bracelets, Multigem Bracelets, Nylon Bracelets, Brass Bracelets, Wood Bracelets and Beaded Bracelets.

This morning, visit Barton Creek Cave and learn about how the cave served as a gateway to the underworld for the ancient Maya, and paddle a canoe along its aqueous passageways, studded with sparkling calcite crystals.

Stalactites and Stalagmites hang high overhead as we float past impressive calcite crystals.

This system, designed by Chicago Fly House, employs a 400 pound limestone and calcite rock from the local Bolingbrook quarry as counterweight to elevate a person safely strapped into a chair high enough to see over the lip of the hole.

Many artworks encourage interaction, such as Mr. Falls» Healing Pavilion, a seating area made from gemstones with healing properties like amethyst, orange calcite, jasper, lapis lazuli and rose quartz.

The color yellow persists as paint residue on the excavator heads and is reflected again in the yellow - hued banded calcite, which, though mined by similar machinery through a process of destruction, now rests in perfect equilibrium in the grip of the sculpture — an essential part of the work.

Despite Bart's odd chemistry — extra C03 (and an extra «proton») scavenges Ca from the water column — where it is supersaturated and goes back and forwards into and out of solution as ions or as the solid calcium carbonate (CaCO3) polymorphs of aragonite and calcite predominantly.

The Patagonian Shelf Break lies on the northern edge of a region that some scientists refer to as the «great southern coccolithophore belt» or the «great calcite belt.»

Now let's look at Keigwin's justly famous Sargasso Sea dO18 proxy temperature reconstruction: (1996) «The Little Ice Age and Medieval Warm Period in the Sargasso Sea» Science 274, 1503 - 1508 This isn't meant as a general criticism, however, the reconstructed Sargasso Sea paleotemperature rests on Globigerinoides ruber calcite.

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.

But since corals, be it with an aragonite or a calcite skeleton, both rely on symbiotic algae as their main source of energy they remain vulnerable, since those algae are highly susceptible to both low pH and high temperatures.

The climate records of calcite shells show that yesterday's Arctic — as in during the Ice Age — had warm water.