AGGRESSIVE MEDIUM

This equation is based on numerous tests on samples of 3003 in 67 waters of increasing aggressivity. Calculations based on this equation are in good accordance with experimental results in very aggressive water, but for waters of medium aggressivity, they yield a higher pit deepening rate than what is observed in reality. 

Almost all cooling water system deposits are waterborne. It would be impossible to list each deposit specifically, but general categorization is possible. Deposits are precipitates, transported particulate, biological materials, and a variety of contaminants such as grease, oil, process chemicals, and silt. Associated corrosion is fundamentally related to whether deposits are innately aggressive or simply serve as an occluding medium beneath which concentration cells develop. An American... 

Corrosion protection measures are divided into active and passive processes. Electrochemical corrosion protection plays an active part in the corrosion process by changing the potential. Coatings on the object to be protected keep the aggressive medium at a distance. Both protection measures are theoretically applicable on their own. However, a combination of both is requisite and beneficial for the following reasons ... 

Air heaters in industrial environments require corrosion-protective finishes that are capable of protecting the coil and case from damage by condensation, acid vapors, or aggressive chemicals, in the air or the primary medium. If air washers are used with coils placed after them, copper or other noncorroding metal tubes should be used. 

Process severity The indication of the degree of aggressiveness of the process medium on the hardware expressed as categories 1 through 4, which correspond to Clean, General Industry, Moderately Severe, and Severe, respectively. 

The necessity of electronic insulation — the origin of the term separator — has to be met durably, i.e., often over many years within a wide range of temperatures and in a highly aggressive medium. Under these conditions no substance harmful to the electrochemical reactions may be generated. 

For the designer it is not important whether cracking develops upon exposure to a benign or an aggressive medium. The important considerations are the embrittlement itself and the fact that apparently benign environments can cause serious brittle fractures when imposed on a product that is under sustained stress and strain, which is true of certain plastics. 

Because water is a common solvent we might think of it merely as a passive medium in which chemical reactions take place. However, water is a reactive compound, and an alien raised in a nonaqueous environment might consider it aggressively corrosive and be surprised at our survival. For instance, water is an oxidizing agent ... 

For all these reasons, the stability of the superconducting state and ways to control it are questions of prime importance. Many studies have addressed the degradation of the properties of HTSC under the influence of a variety of factors. They included more particularly the corrosion resistance of HTSC materials exposed to aqueous and nonaqueous electrolyte solutions as well as to water vapor and the vapors of other solvents. It was seen that the corrosion resistance depends strongly both on the nature (chemical composition, structure, etc.) of the HTSC materials themselves and on the nature of the aggressive medium. 

Since there would be increased overall lipid concentration in the dodecane solution, we decided to create a sink condition in the acceptor wells, to lower the membrane retention. We discovered that the pH 7.4 buffer saturated with sodium laurel sulfate serves as an excellent artificial sink-forming medium. Since the new PAMPA membranes would possess substantial negative charge, the negatively charged micellar system was not expected to act as an aggressive detergent to the two-component artificial membrane infused in the microfilter. 

A similar example of curing inhibition In an acidic medium has been observed when moderate amounts of salicylic acid were added to epoxy-amine matrix systems. (26) Such behavior may beresponsible for the poor bond strengths observed with the NTMP-containing oxide-primer specimens. In environments containing an aggressive species (e.g.. Cl ), the anion may interact with and become incorporated into the NTMP-oxide matrix, whereby it can attack the metal surface. 

Floating Bladders. The "floating bladder" principle is used under extreme corrosion conditions. The balloon is made of an alloy which is resistant to the extremely aggressive medium and is surrounded by pressurized water so that the internal pressure of the bal loon... 

Nevertheless, the radiolytic (and hydrolytic) stability of an extractant must be considered not only from the quantitative, but also from the qualitative aspect. The objective is not perfect resistance to the aggressive medium, but sufficient for an industrial implementation of the process. The nature of the stable compounds, their distribution in the process steps, and their impact are also important when proposing an efficient solvent cleanup. For such studies, dedicated representative loops in which the main treatments, extraction-irradiation-stripping-solvent treatment, could be run on the solvent are of key importance. 

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