Regenerative methods

Other regenerative methods are occasionally used to remove HjS from hydrocarbons, such as the tri- potassium phosphate (TPP) process. Other installations are DEA or ME A, and most TPP units have been converted to DEA since the latter consumes less steam for regeneration. 

These are regenerative methods since the systems in question can usually be made from olefins. Employed in this way, they are frequently useful in the isolation, purification or protection of olefins. Alternatively, independent routes to the difunctional system are available and constitute legitimate olefin syntheses. 

The CaS04 formed is stable, thus can safely be stored. However, the management of massive quantities of CaS04 that accumulate over a period of time can be a disposal problem. Other regenerative methods of SO2 removal have also been developed. ... 

Miscellaneous Systems Many other systems have been proposed for transferring heat regeneratively, including the use of high-temperature hquids and fluidized beds for direct contact with gases, but other problems which hmit industrial application are encountered. These svstems are covered by methods described in Secs. 11 and 12 of this handbook. 

As the DI plant becomes exhausted, silica leakage occurs in the treated MU water and the pH falls abruptly. Furthermore, where sodium ion leakage occurs from the cation bed, it produces a regenerative effect on the anion bed, which may also lead to silica leakage. To differentiate between the two phenomena, sodium ion leakage from the cation bed should be assessed directly using selective sodium-ion electrodes, flame photometric analysis, or other appropriate test methods. 

The regenerative capacity of bone is robust and effective at addressing wounds under normal conditions. A proportion of fractures, however, present conditions that are not conducive to regeneration and place the fracture at high risk for nonunion or delayed union. For example, fractures located at sites of marginal vascularity and those associated with a large area of bone loss repair with difficulty if at all. As a result, a great deal of effort has been invested in the development of treatment methods for fractures and defects at risk of nonunion, as they would not likely heal... 

Diene)Mn(CO)3 anions are also prepared by deprotonation of the ( j3-allyl-/r-hydride) Mn(CO)3 complexes (25 MLn = Mn(CO)3) with potassium hydride23 90a c. However, since complexes 25 MLn = Mn(CO)3 are generally prepared by protonation of the corresponding anions, this method is mostly of regenerative value. 

Musculoskeletal Effects. Few musculoskeletal effects have been reported in the literature after an acute, intermediate, or chronic exposure to chloroform in humans or in laboratory animals. Larson et al. (1996) investigated the ability of acute- and intermediate-duration exposure to chloroform vapor to produce toxicity and regenerative cell proliferation in various tissues of female B6C3Fi mice. Using the methods described in previous sections of this profile, Larson et al. (1996) found that, after acute exposure, no microscopic changes were noted in nonnasal bones, nor were non nasal bone Lis different from those of controls. In the intermediate duration studies, no alterations in nonnasal bone tissues were noted at any exposure level in either sex after exposures of 3, 6, or 13 weeks. 

The applicability of the foregoing procednre has been tested by modeling simple reaction under semi-infinite diffusion conditions (reaction 1.1) and EC mechanism coupled to adsorption of the redox couple (reaction (2.177)) [2]. The solutions derived by the original and modified step-function method have been compared in order to evaluate the error involved by the proposed modification. As expected, the precision of the modified step-function method depends solely on the value of p, i.e., the number of time subintervals. For instance, for the complex EC mechanism, the error was less than 2% for p>20. This slight modification of the mathematical procedure has opened the gate toward modeling of very complex electrode mechanisms such as those coupled to adsorption equilibria and regenerative catalytic reactions [2] and various mechanisms in thin-film voltammetry [5-7]. 

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