Chemical plating method

All AB, alloys are very brittle and are pulverized to fine particles in the hydrid-ing-dehydriding process (see Sec. 7.2.1). Thus electrodes must be designed to accommodate fine powders as the active material. There are several methods of electrode fabrication Sakai et al [35] pulverize the alloy by subjecting it to several hydrogen absorption-desorption cycles, before coating the resulting particles with Ni by chemical plating. The powder is mixed with a Teflon dispersion to obtain a paste which is finally roller-pressed to a sheet and then hot-pressed to an expanded nickel mesh. The fabrication of a simple paste electrode suitable for laboratory studies is reported by Petrov et al. [37],... 

Previous studies focusing on deposition of Cu [6, 15] or Ni [16] coatings and deposits on natural and synthetic graphics relied on an electroless plating method [25]. In this method many different chemical solutions are used in multiple steps to treat the graphite surface, such as... 

It is a great deal of work to actually determine a true equilibrium constant and most chemical separation methods speak in terms of values which are proportional to the actual equilibrium constant. At constant flow, the time that a given type of molecule is retained is related to the time for the void volume to pass after the sample is placed in a column or on a plate with the addition of the time for the net retention volume. If the flow remains constant, the temperature of the separation remains constant and no stationary phase is gained or lost, one can attempt qualitative identification using retention times. It is more reasonable to calculate the ratio of net retention volume to the void volume and call the result partition factor or capacity factor, k. ... 

Two arguments can he put forward in favour of wet chemical decomposition methods in open vessels, firstly, price, and, secondly, sample throughput. A wet decomposition can, if necessary, be performed with a beaker and a heating plate, whereas apparatus for modem high performance decompositions can cost as much as 25 000. With respect to sample throughput, the automatic wet digestion device can be used for up to 1 SO samples per hour for some materials. Such throughput cannot be realized by any other method. Some special cases exist that necessitate decomposition in open vessels (for instance, when the sample needs to be treated with perchloric acid). 

Liu, D. Chau, Z.K. Dutka, B.J. Rapid toxicity assessment of water-soluble and water-insoluble chemicals using a modified agar plate method. Water Res. 1989, 23, 333-339. 

Liu, D., Kwasniewska, K., Chau, Y. and Dutka, B. (1991) A four-hour agar plate method for rapid toxicity assessment of water-soluble and water-insoluble chemicals, Environmental Toxicology and Water Quality 6, 437-444. 

Numerous plating and metal finishing plants use chemical oxidation methods to treat their cyanide wastes cyanides and heavy metals are often present together in plating industry waste. Their concentration and their value influence the selection of the treatment process. If the cyanide and heavy metals are not economically recoverable by a method such as ion exchange, the cyanide radical is converted either to the less toxic cyanate or to carbon dioxide and nitrogen by oxidation, while the heavy metals are precipitated and removed as sludge. 

MOLDING/METALLIZATION. Molded thermoplastic circuit board substrates may be rendered selectively conductive by several additive process techniques including conductive polymeric thick film inks (PTF), and semi and fully additive electroless/electrolytic platings. Of the various chemical process methods developed to produce circuitry on a molded plastic substrate, one method practiced by Pathtek, A Kodak Company, combines both "catalytic" and "non-catalytic" resins in a highly automated commercialized two-shot molding/selective metallization process. 

Resistance to bacitracin does not emerge rapidly in originally susceptible strains. The thermal and storage stability of bacitracin is enhanced by the presence of an equimolar concentration of Zn " and the antibacterial action is potentiated by an excess of Zn " ". It has been suggested that Zn + is also associated with the mechanism of antibacterial action. No chemical assay methods are yet available for bacitracin. For the determination of potency the cylinder plate method with Micrococcus flavus (ATCC 10 240) as test organism is used. ... 

The solvent-extraction process for metal ions depends intrinsically on the mass transfer to or across the interface and the chemical reaction in the interfacial region. Therefore, the study of the role of the interface is very important for analyzing the real extraction mechanism and for controlling the extraction kinetics. In the early 1980s, the high-speed stirring (HSS) method was developed by Watarai and Preiser [4,5]. Thereafter, some new methods were proposed in our laboratory, which included the two-phase stopped-flow method [6], the capillary plate method [7], reflection spectrometry [8], the centrifugal liquid membrane (CLM) method [9], and the two-phase sheath flow method... 

Current wet chemical preconcentration methods include extraction, absorption in wash solutions or concentration on filters, chromatographic concentrations on plates and columns, etc. 

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