Nickel texture

Selenium is added up to 0.1% to silicon steels (2—4% Si) used in transformer cores to enhance the development of the secondary recrystallization texture which, in turn, improves the magnetic characteristics. Selenium alloying additions to the melt may be made as elemental Se, nickel—selenium, or ferroselenium. The recovery depends on the melting practice and method of addition. Normally, it is in the range of 66%, but may be as high as 90%. 

Finely powdered cobalt can detonate spontaneously in air. Its behaviour depends on its surface texture. Raney cobalt is much more dangerous than Raney nickel, which is more commonly used (see nickel). 

Other possibility is the application of sonication during the dissolution of electrodeposited metals such as copper or nickel [74]. For both, the texture coefficient of the dissolved plane is affected, and is dependent on the plastic deformation by the shock wave and jet flow pressures. For both metals, the author sees that the greatest effect of ultrasound is located around 20 and 40 kHz. However, there is a marked difference between the two metals. Copper demonstrated the greatest effects at 45 kHz while nickel was most dramatically affected at the lower frequency of 28 kHz, but the possible reasons for that are not provided by the authors. 

Raney Not a process, but a nickel catalyst widely used for hydrogenating organic compounds. It is made from a 50/50 nickel/aluminum alloy by leaching out the aluminum with concentrated aqueous sodium hydroxide. The product has a spongy texture and is highly active. Invented by M. Raney in 1926. The business was acquired by W. R. Grace in 1963. U.S. Patent 1,628,190. 

Here we examine models that try to explain how textures develop during deposition on oriented (single-crystal), textured, polycrystalline, and amorphous substrates. We select electrodeposition of nickel as a model system. 

Information on nickel exposure from hazardous waste sites is lacking. The most probable route of exposure from hazardous waste sites would be dermal contact, inhalation of dust, and ingestion of nickel-contaminated soil. Groundwater contamination may occur where the soil has a coarse texture and where acid waste, such as waste from plating industries, is discarded. People using this water may be exposed to high levels of nickel. 

Nickel is strongly adsorbed by soil, although to a lesser degree than lead, copper, and zinc (Rai and Zachara 1984). There are many adsorbing species in soil, and many factors affect the extent to which nickel is adsorbed, so the adsorption of nickel by soil is site specific. Soil properties such as texture, bulk density, pH, organic matter, the type and amount of clay minerals, and certain hydroxides influence the retention and release of metals by soil (Richter and Theis 1980). 

Ermakova and co-workers manipulated the Ni particle size to achieve large CF yields from methane decomposition. The Ni-based catalysts employed for the process were synthesized by impregnation of nickel oxide with a solution of the precursor of a textural promoter (silica, alumina, titanium dioxide, zirconium oxide and magnesia). The optimum particle size (10 0 nm) was obtained by varying the calcination temperature of NiO. The 90% Ni-10% silica catalyst was found to be the most effective catalyst with a total CF yield of 375 gcp/gcat- XRD studies by the same group on high loaded Ni-silica... 

Chondrules exhibit a bewildering variety of compositions and textures (F ig. 6.1 a,b). Most are composed primarily of olivine and/or pyroxene, commonly with some glass. (For a crash course in mineral names and compositions, see Box 6.1.) If melt solidifies so quickly that its atoms cannot organize into crystalline minerals, it quenches into glass. Iron-nickel metal and iron sulfide occur in many chondrules, often clustered near the peripheries. The textures of... 

When nucleate boiling takes place on a hot solid, the surface texture of that solid becomes an important variable. A thorough study was made by Corty and Foust (C4), who boiled ether, pentane, and Freon-113 from horizontal, electrically heated copper and nickel surfaces. The surface texture was altered at will by use of different grades of emery polishing paper. 

Fig. 30. Effect of surface texture on nucleate boiling. Ether was boiled on a nickel plate polished with different grades of emery paper. The pressure was atmospheric. Typical data are given for one curve only (C4).

Liquid-phase hydrogenation of 1,4 butynediol to cis-1,4-butenediol and 1,4-butanediol has been carried out on nickel catalysts supported on thirteen different supports. Some commercial nickel catalysts were used as references. Furthermore, metal loading and Ni-Cu alloying have also been studied. The results obtained indicates that catalytic activity, selectivity and metal surface area of catalysts are closely correlated to some textural and/or acid-base properties of the corresponding support. Similarly, the influence of Cu as a second metal in catalyst behaviour is also related to the nature of the support. 

Different nickel deposits show a great variety of contact resistance values. This is particularly so after the deposits have been exposed to the atmosphere for an extended period of time. The differences between these values may be best explained in terms of variations in plated texture. Nickel electrodeposits with polycrystalline nature have been observed to behave as single crystals ( ) when their grains were oriented such that the (100) plane was parallel to the surface. Not surprisingly, the oxidation rate in (lOO)-oriented single crystals is self-limiting at ambient temperature. 

II. Texture and Structure of Nickel-Silica Catalysts 1. Introduction... 

The first question in the study of the properties of binary catalysts such as the nickel-silica system concerns its texture. A priori, we can hazard a reasonable guess as to the building system that we are going to encounter. It is well known that silica forms a porous system and one may therefore... 

Engineering the required texture in a (RE)BCO tape is a much more complex matter than in the case of the Bi-2223 tape. One approach is to prepare a nickel tape with a carefully controlled crystalline surface texture. This forms the substrate for the development of a correspondingly textured thermally grown oxide layer which, in turn, forms the substrate for the epitaxial growth of MgO by electron beam evaporation. The textured MgO serves as the substrate for the epitaxial growth of the 1 /mi thick (RE)BCO via pulsed laser deposition. 

Very attractive finishes can be obtained from rollers formed by electrodeposition of nickel, including leather, textiles, and other natural and synthetic textures. This method allows the faithful reproduction of a finish across the full width of the cylinder and, since undercuts cannot be achieved by the milling process, gives a more realistic appearance in (as an example) woven designs. 

In a rotary screen system plastisols for compact and textured products are applied to suitable substrates continuously from seamless, cylindrical nickel screens. The plastisols are fed into the screens and pressed through perforations to the substrate by a squeegee of flexible steel or rubber the substrate is supported by a counter-pressure roller, usually of chromium-plated steel. The principle is illustrated in Figure 111. 

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