The scanning electron microscopy (SEM) allowed to corroborate the presence of some elements of the lantanoid type: praseodymium (Pr), neodymium (Nd), cerium (Ce), ytterbium
(Yb), as well as toxic metals, lead (Pb), associated to minerals of the rare earth phosphate-type.
and cobalt concentrations were determined using an Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) (Perkin Elmer, Precisely, Optima 5300 DV Spectrometer, Shelton, CT, USA).
The elements identified in case of Thar 11-2 coal sample, were Arsenic, Barium, Bromine, Calcium, Cerium, Cobalt, Chromium, Cesium, Copper, Iron, Hafnium, Lanthanum, Manganese, Molybdenum, Niobium, Neodymium, Nickel, Lead, Rubidium, Antimony, Scandium, Selenium, Strontium, Titanium, Uranium, Vanadium, Tungsten, Yttrium, Ytterbium
, Zink and Zirconium.
Rare earths are 17 chemical elements in the periodic table, specifically 15 lanthanides: lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium
, lutetium, as well as scandium and yttrium.
The strontium clock's stability-the extent to which each tick matches the duration of every other tick-is about the same as NIST's ytterbium
atomic clock, another world leader in stability unveiled in August, 2013.
In her work, Rey chills strontium and ytterbium
atoms to a billionth of a Kelvin, close to absolute zero.
Bouhafs, "Study of ytterbium
doping effects on structural, mechanical and opto-thermal properties of sprayed ZnO thin films using the Boubaker Polynomials Expansion Scheme (BPES)," Journal of Alloys and Compounds, vol.
Although monochromatic quantum efficiency of 0.3% has been reported for upconversion in nanocrystalline [NaYF.sub.4] doped with ytterbium
([Yb.sup.3+]) sensitizer and erbium ([Er.sup.3+]) activator , the overall light capture efficiency of lanthanide-based upconverters is limited by the narrow spectral width and the low absorption cross-section of the atomic transitions.
For this purpose, Rheinmetall eventually turned onto ytterbium
(Yb) fibre lasers from IPG Photonics in Germany to build its "beam forming unit" -based weapons.
Desorption of lanthanum, europium and ytterbium
The clock, made from the element ytterbium
, could be used for technological