noble metal


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metal

 [met´'l]
any chemical element marked by luster, malleability, ductility, and conductivity of electricity and heat, and which will ionize positively in solution. adj., adj metal´lic.
alkali metal one of a group of monovalent elements including lithium, sodium, potassium, rubidium, and cesium.
metal fume fever an occupational disorder with malaria-like symptoms occurring in those engaged in welding and other metallic operations and due to the volatilized metals. It includes brassfounder's fever (brass chill, brazier's chill) and spelter's fever (zinc chill, zinc fume fever).
heavy metal one with a high specific gravity, usually defined to be above 5.0.
heavy metal poisoning poisoning with any of the heavy metals, particularly antimony, arsenic, cadmium, lead, mercury, thallium, or zinc.
noble metal a metal that is highly resistant to oxidation and corrosion.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

no·ble met·al

a metal that cannot be oxidized by heat alone, nor readily dissolved by acid, for example, gold, platinum.
Synonym(s): noble element
Farlex Partner Medical Dictionary © Farlex 2012

noble metal

A metal that resists corrosion or oxidation. Examples are gold, platinum, and silver.
See also: metal
Medical Dictionary, © 2009 Farlex and Partners

no·ble met·al

(nōbĕl metăl)
Any metallic element used in dental restorations and appliances that resists tarnish, corrosion, and oxidation during heating or in intraoral environments (e.g., gold, platinum).
Medical Dictionary for the Dental Professions © Farlex 2012
References in periodicals archive ?
In this study, we designed a hydrophilic adsorbent bearing thiocarbonyl moieties for selective adsorption of noble metals in an organic solvent free manner.
Apart from the effect caused by the catalyst of metal surface, the wide differences in activation temperatures for deiodination versus debromination on noble metal surface can be utilized for a defined sequential coupling depending on selective activation of iodine and bromine sites [15].
Hybrid phosphorene that is created by noble metal adatoms provides great interest to researchers in catalysis and nanoelectronic devices [37,38].
Under UV irradiation noble metal nanoparticles deposited on Ti[O.sub.2] enhance transfer of photogenerated electrons prolonging lifetime of the charge carriers (see Figure 5(b)).
Therefore, the substitution of the noble metal with TiO to enhance the photocatalytic activity of Ti[O.sub.2] has much application value.
Owing to PMAA microspheres other than PVDF absorbing metal ions, the PMAA microspheres thus can be further used to introduce Au, Ag, and Pd NPs to the membrane pores by in site reduction of the adsorbed noble metal ions [31].
Noble metal nanoparticles exhibit a strong optical absorption in the visible range of the electromagnetic spectrum due to the existence of a resonance of the localized surface plasmon (LSP), a nonpropagating collective oscillation mode of the conduction electrons of metallic nanostructures [17].
In addition, the intensities of some peaks increase and decrease depending on the added noble metal. The [Ni.sub.75][Al.sub.24][Ag.sub.1] profile shows highest intensities in (100) and (200), and the intensity of the peak decreased in (111); this suggests the crystal growth in two preferential planes.
We found that risky entry is more likely when (1) MNCs have longer experience of foreign operations (p < 0.01), (2) the percentage of rare metal mines is lower (p < 0.05), (3) the percentage of noble metal mines is lower (p < 0.001), (4) MNCs have invested less in the previous 7 years (p < 0.05), (5) MNCs' home countries are economically weaker (p < 0.10), and (6) the host countries that MNCs enter are economically weaker (p < 0.01), more politically stable (p < 0.001), and more democratic (p < 0.05).
The results of this study suggest chlorine gas plays an important role in the degradation of noble metal finishes like immersion silver (ImAg) and electroless nickel immersion gold (ENIG) and may exacerbate lateral creep corrosion development of unprotected copper areas in a noncondensing MFG environment.
In topical skin preparations, the noble metal is included as colloidal silver (suspension of silver particles in an aqueous base) or nanosilver (as nanoparticles ranging from 1 nm to 100 nm in at least one dimension).