Systemic nickel

Electroplating. The second-largest appHcation for nickel chemicals is as electrolytes ia nickel electroplating (qv). In ordinary plating systems, nickel present ia the electrolyte never forms on the finished workpiece the latter results from dissolution and transfer from nickel anodes. Decorative nickel plating is used for automobile bumpers and trim, appHances, wire products, flatware, jewelry, and many other consumer items. A comprehensive review of nickel electroplating has been compiled (164). 

As with most other metal and alloys systems, nickel and certain of its alloys may suffer intergranular corrosion in some circumstances. In practice, intergranular corrosion of nickel alloys is usually confined to the vicinity of welds as a result of the effects produced by the welding operation on the structure of the material in those regions. Alloys that are subjected to other similarly unfavourable thermal treatments may also become susceptible. The compositions of most commercial nickel alloys that are marketed today are. 

Juza, R., u. W. Sachsze Zur Kenntnis des Systems Nickel/Stickstoff. Z. 

Toxic effects of nickel to humans and laboratory mammals are documented for respiratory, cardiovascular, gastrointestinal, hematological, musculoskeletal, hepatic, renal, dermal, ocular, immunological, developmental, neurological, and reproductive systems. Nickel toxicity in mammals is governed by the chemical form of nickel, dose, and route of exposure. Mammalian exposure to nickel by inhalation or cutaneous contact was more significant than oral exposure. To protect humans and other mammals against respiratory effects, proposed air-quality criteria are 0.01 to less than... 

Industrially this diene is made the same way as ethylidenenorbomene from butadiene and ethene, but now isomerisation to 2,4-hexadiene should be prevented as the polymerisation should concern the terminal alkene only. In both systems nickel or titanium hydride species react with the more reactive diene first, then undergo ethene insertion followed by (3-hydride elimination. Both diene products are useful as the diene component in EPDM rubbers (ethene, propene, diene). The nickel hydride chemistry with butadiene represents one of the early examples of organometallic reactions studied in great detail [22] (Figure 9.14). 

The nickel-based systems include the flowing systems nickel—iron (Ni/Fe), nickel—cadmium (NiCd), nickel—metal hydrides (NiMH), nickel—hydrogen (Ni/ H2), and nickel—zinc (Ni/Zn). All nickel systems are based on the use of a nickel oxide active material (undergoing one valence change from charge to discharge or vice versa). The electrodes can be pocket type, sintered type, fibrous type, foam type, pasted type, or plastic roll-bonded type. All systems use an alkaline electrolyte, KOH. 

To prevent systematic mistakes in the dilution series of the ligand standard solutions, leading to relative shifts in the [L]-control maps, we carried out independent control catalyses on the 250-ml scale. For the ([L]o/[Ni]o) ratio we selected inflection points in the varying product distribution of the [L]-control maps. In Fig. 3.2-2 is exemplified the [L]-control map of the catalytic system nickel/phenyl-diphenoxi-phos-phine/butadiene. ... 

In Scheme 3.3-1 the [L]-control maps for the three-component system nickel/ triphenylphoq>hine/butadiene and the four-component system nickel/triphenyl-phosphine/butadiene/propene are compared. The amount of the produced... 

In the system nickel/L/butadiene, secondary amines can shift the cyclodimerization of butadiene to the acyclic products (7a) and (75) Its cocatalyst functfon can be visualized by the corresponding [L]-control map (Scheme 3.3-2). In the three-component system nickel/morpholine/butadiene the open-chain products are formed for log ([morpholine]o/[Ni]o) > -1. Both octatrienes (7a) and (75) are formed at the constant ratio of 1.8 over the entire range of the examined amine/nickel scale. However, the efficiency of the catalytic system is low. After a turnover of 30% butadiene, the catalytic activity ends because of the formation of stop complexes of the nickel amide type. 

Little is known concerning the chemistry of nickel in the atmosphere. The probable species present in the atmosphere include soil minerals, nickel oxide, and nickel sulfate (Schmidt and Andren 1980). In aerobic waters at environmental pHs, the predominant form of nickel is the hexahydrate Ni(H20)g ion (Richter and Theis 1980). Complexes with naturally occurring anions, such as OH, SO/, and Cf, are formed to a small degree. Complexes with hydroxyl radicals are more stable than those with sulfate, which in turn are more stable than those with chloride. Ni(OH)2° becomes the dominant species above pH 9.5. In anaerobic systems, nickel sulfide forms if sulfur is present, and this limits the solubility of nickel. In soil, the most important sinks for nickel, other than soil minerals, are amorphous oxides of iron and manganese. The mobility of nickel in soil is site specific pH is the primary factor affecting leachability. Mobility increases at low pH. At one well-studied site, the sulfate concentration and the... 

Flint GN, Packirisamy S. 1995. Systemic nickel The contribution made by stainless-steel cooking utensils. Contact Dermatitis 32 218-224. 

A nickel-based catalyst system, which produces, in the absence of comonomers, highly short-chain branched polyethene was developed by Brookhart et al. [23]. Independently, the groups of Brookhart [24, 25, 26] and Gibson [27, 28, 29, 30] developed efficient iron- and cobalt-based catalyst systems. Nickel or palladium is typically sandwiched between two a-di-imine ligands, while iron and cobalt are tridentate complexed with imino and pyridyl ligands. 

S. Budurov, G. Wassiliew, Nguen Thi Kuck. Die Wachstumpskinetik von Schlichten intermetallischer Phasen im System Nickel-Zink // Z.Metallkunde.- 1977.-V.68, No.3.-P.226-230. 

Sandrock, G. D., A New Family of Hydrogen Storage Alloys Based on the System Nickel-Mischmetal-Calcium, "Proc. 12th IECEC", 1977, 1, 951, Washington, DC. 

No indication of the existence of this compound has been obtained by Bornemann 2 in studying the freezing-point curve of the system nickel—sulphur. 

The fibers were annealed at 200 C for 5 min. in N2, wound parallel on a sample holder and flat plate X-ray photographs taken by exposing the fibers for 1 h (WAXS) to a beam collimated at 90° to the fiber axis, uatorial diffractometer traces of uniaxially oriented fibers were taken uring slit collimation. WAXS patterns were obtained on polaroid film and the difoctometer traces with a Siemens X-ray system. Nickel filtered CuKa radiation was used. The X-ray unit was operated at 30 KV and 20 mA. The sample to film distance was 71.4 mm. 

Ethylene glycol can be used to reduce metal ions to the metallic state. All the noble metals can be easily reduced by heating the metal salt in glycol at temperatures of 120 to 200°C, and therefore reactions can be carried out in an open system. Nickel is also reduced, but iron is not reduced to the metallic state. This method was first reported by Figlarz et al and they called this method the polyol process. 

Kwak JCT, Nelson RWP. Mean activity coefficients for the simple electrolyte in aqueous mixtures of polyelectrolyte and simple electrolyte. 4. The systems nickel chloride—nickel poly(styrenesulfonate), zinc chloride—zinc poly-(styrenesulfonate), and cadmium chloride—cadmium poly(styrenesulfonate). J Phys Chem 1978 82 2388-2391. 

One of the systems considered on which reliable data were available was No. 3 (Table I), the hydrogen-supported nickel system. Nickel is known to be highly adsorbing but certainly is not the only adsorbent of this type. 

Metals (i.e., nickel and vanadium) also occur within the asphaltene fraction but are much more difficult to visualize as part of the asphaltene system. Nickel and vanadium occur as porphyrins (74-77), but whether these are an integral part of the asphaltene structure is not known. Some of the porphyrins can be isolated as a separate stream from petroleum (77). 

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