Y alloy See aluminium alloys. Yb Ytterbium.  [c.431]

The main technical specifications of the isotope sources iridium, Selenium and Ytterbium are included in Table 1. The spectrum of Selenium is dominated by two lines of energy at 137 keV and 265 keV the total spectrum consists of nine lines in the range fi om 66 to 401 keV. The resultant average energy of 217 keV is significantly lower than the average energy of 353 keV for iridium. This lower energy provides better contrasts of radiographs.  [c.424]

A further advantage is the Selenium halflife of 120 days, which is 60% more when compared to iridium and a factor of approx. 4 when compared to Ytterbium. These differences turn out to be an important economical aspect when comparing the different sources, as they are a direct measure of the useful life of sources. The short halflife and the very high costs for Ytterbium sources have been the main factors for the rather low importance of Ytterbium in the full range of gamma radiography.  [c.424]

Ytterbium occurs along with other rare earths in a number of rare minerals. It is commercially recovered principally from monazite sand, which contains about 0.03%. Ion-exchange and solvent extraction techniques developed in recent years have greatly simplified the separation of the rare earths from one another.  [c.196]

The element was first prepared by Klemm and bonner in 1937 by reducing ytterbium trichloride with potassium. Their metal was mixed, however, with KCl. Daane, Dennison, and Spedding prepared a much purer from in 1953 from which the chemical and physical properties of the element could be determined.  [c.196]

Ytterbium metal has possible use in improving the grain refinement, strength, and other mechanical properties of stainless steel. One isotope is reported to have been used as a radiation source substitute for a portable X-ray machine where electricity is unavailable. Few other uses have been found.  [c.197]

Ytterbium metal is commercially available with a purity of about 99+% for about 875/kg.  [c.197]

Ytterbium has a low acute toxic rating.  [c.197]

As anticipated from the complexation experiments, reaction of 4.42 with cyclopentadiene in the presence of copper(II)nitrate or ytterbium triflate was extremely slow and comparable to the rate of the reaction in the absence of Lewis-acid catalyst. Apparently, Lewis-acid catalysis of Diels-Alder reactions of p-amino ketone dienophiles is not practicable.  [c.115]

IV) oxide sulfate (III) sulfate (III) sulfide Xenon difluoride hexafluoride tetrafluoride trioxide Ytterbium  [c.270]

Above room temperature, the trivalent lanthanide ions are paramagnetic, with the exception of diamagnetic lanthanum and lutetium. Tetravalent cerium and divalent ytterbium are also diamagnetic. For the metals, when the temperature is lowered, the spin and orbital moments line up. The metals become antiferromagnetic or even ferromagnetic, eg, gadolinium, terbium, or dysprosium. The magnetism of the rare earths is highly anisotropic and is important in some industrial appUcations.  [c.540]

Gammagraphic weld inspection in the lower range of steel thicknesses has been done with Iridium and Ytterbium isotope sources throughout the past. The large majority of applications has been using Iridium due to the unfavourable economical parameters of Ytterbium, obviously with non-optimal results at thin wall inspections.  [c.423]

Ytterby, a village in Sweden near Vauxholm) Yttria, which is an earth containing yttrium, was discovered by Gadolin in 1794. Ytterby is the site of a quarry which yielded many unusual minerals containing rare earths and other elements. This small town, near Stockholm, bears the honor of giving names to erbium, terbium, and ytterbium as well as yttrium.  [c.73]

Ytterbium has a bright silvery luster, is soft, malleable, and quite ductile. While the element is fairly stable, it should be kept in closed containers to protect it from air and moisture. Ytterbium is readily attacked and dissolved by dilute and concentrated mineral acids and reacts slowly with water. Ytterbium has three allotropic forms with transformation points at -13oC and 795oC. The beta form is a room-temperature, face-centered, cubic modification, while the  [c.196]

Ytterbium Dissolve 1.6147 g YbCl3 in water and dilute to volume.  [c.1186]

Although rare-earth ions are mosdy trivalent, lanthanides can exist in the divalent or tetravalent state when the electronic configuration is close to the stable empty, half-fUed, or completely fiUed sheUs. Thus samarium, europium, thuUum, and ytterbium can exist as divalent cations in certain environments. On the other hand, tetravalent cerium, praseodymium, and terbium are found, even as oxides where trivalent and tetravalent states often coexist. The stabili2ation of the different valence states for particular rare earths is sometimes used for separation from the other trivalent lanthanides. The chemicals properties of the di- and tetravalent ions are significantly different.  [c.540]

Parameter Gadolinium Terbium Dysprosium Holmium Erbium ThuUmn Ytterbium Lutetium  [c.541]

See pages that mention the term Yterbium : [c.46]    [c.235]    [c.431]    [c.431]    [c.196]    [c.196]    [c.196]    [c.197]    [c.197]    [c.198]    [c.217]    [c.280]    [c.309]    [c.327]    [c.349]    [c.359]    [c.382]    [c.653]    [c.673]    [c.722]    [c.843]    [c.849]    [c.913]    [c.914]    [c.964]    [c.1143]    [c.1081]    [c.1081]    [c.1081]    [c.217]    [c.539]    [c.542]    [c.52]   
Organic syntheses based on name reactions and unnamed reactions (1994) -- [ c.136 ]