Nickel General

Compounds containing such metals as copper, barium, lead, molybdenum, and nickel generally are not used in processing solutions. However, trace quantities of certain metal dopants occasionally are used to impart desired soHd-state and photographic properties to emulsion grains. Because of its... 

Tien and Howson 1981 Winhdolz 1983. Names refer to alloys of nickel. Generally there is a series of alloys with the same trade name (e.g.. Monel alloy K-400, Monel alloy K-500). 

It was hoped that the resulting benzylic carbinols 59 could be stereose-lectively reduced by catalytic hydrogenation to the required protected kainoid derivatives 60 (Scheme 24). The reduction of benzylic alcohols varies in stereospecificity depending on the catalyst employed.53 Hydrogenation over Raney nickel generally proceeds via retention of configuration, whereas hydrogenation over palladium on charcoal leads to inversion at the benzylic carbon. 

Studies of chromate production workers, who are exposed to a variety of chromium compounds both hexavalent and trivalent, and chromate pigment industries, where exposure is mainly to chromium(VI), have consistently demonstrated an association with respiratory system cancer. Studies in chrome platers, who are exposed to chromium(VI) and other agents, including nickel, generally support the conclusion that certain chromium(VI) compounds are carcinogenic. Studies in stainless steel welders exposed to chromium(VI) and other chemicals, and in ferrochromium alloy workers, who are exposed mainly to chromium(O) and chromium(III), but also to some chromium(VI), were inconclusive. Studies in leather tanners, who are exposed to chromium(III), were consistently negative. 

Nickel generally forms smooth deposits in sulfate or chloride solutions even in the absence of colloidal addition agents since the deposition of nickel is always accompanied by the simultaneous discharge of hydrogen... 

Ni nickel nickel (general) Ni2+, nickel(2+) Ni3+, nickel(3+) nickelide nickelido... 

Titanium-nickel generally forms a passive Ti02 (rutile) surface layer (Ref 27). Like titanium alloys, there is a transition temperatiire of about 500 °C (930 °F), above which the oxide layer will be dissolved and absorbed into the material. Unlike titanivun alloys, however, no a case is formed. Titanium-nickel will eilso react with nitrogen during heat treatments, forming a TiN layer. 

The important ores of zinc, copper, and nickel generally contain the metal in the form of sulfides or oxides. Sulfides are traditionally processed by high-temperature "roasting," which converts the ore into oxides of the metallic components and sulfur, SO. This technology, dating back many decades, is used in the nickel extraction operations at Sudbury, Ontario,... 

Corrosion can attack iron, copper, or nickel. General corrosion or pitting may occur for conventional reasons, e.g. dissolved oxygen, low pH, presence of deposits, stagnant areas, stress in the metals, defects in metal composition, or surface conditions. Dissolved oxygen often will cause pitting attack when coupled with certain other conditions, such as deposits on the metal surfaces or... 

Indeed, nickel generally forms robust Ni(Lig) complexes with all these ligands in multiple coordination stoichiometries,... 

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