Materials degradation economic effects

LCID RAIN IS AN IMPORTANT AND GROWING TOPIC. This book addresses the important materials problems resulting from acid deposition. It is divided into five sections Measurement and Monitoring of Atmospheric Deposition, Metallic Corrosion, Masonry Deterioration, Degradation of Organics, and Economic Effects. 

The section on economic effects presents the methodology used in assessing costs of degradation of materials due to acid deposition. The difficulty in accurately assessing the cost of materials degradation by acid deposition is described in this section. Thus, the various techniques used have a high degree of uncertainty. 

Heat Sensitivity. The heat sensitivity or polymerization tendencies of the materials being distilled influence the economics of distillation. Many materials caimot be distilled at their atmospheric boiling points because of high thermal degradation, polymerization, or other unfavorable reaction effects that are functions of temperature. These systems are distilled under vacuum in order to lower operating temperatures. For such systems, the pressure drop per theoretical stage is frequently the controlling factor in contactor selection. An exceUent discussion of equipment requirements and characteristics of vacuum distillation may be found in Reference 90. 

Secondary NAAQS are set to protect public welfare. This includes economic losses due to damage to agricultural crops, forests, and materials as well as aesthetic effects, including visibility degradation. 

Com, a grain of major economic importance, is a C4 plant, and many weeds in temperate climates are C3 plants. Therefore the herbicides described in Question 10 are widely used. What effect is likely if these materials are not degraded before they wash into the ocean ... 

The Army conducted a second study to optimize the cost effectiveness of composting. This study used a less expensive carbon-source material, thereby cutting amendment costs from over 200/ton to less than 50/ton, and used a commercially available mechanically agitated composter rather than a static pile. These conditions led to more rapid and extensive degradation of the explosives, achieving cleanup levels of 10 to 20 ppm of TNT and RDX within twenty days. Nevertheless, this method also was determined to be economically infeasible, due to the initial cost of the commercial composter. 

The nse of corrosion inhibitors has grown to be one of the foremost methods of combating corrosion. To use them effectively, the corrosion engineer mnst, first of all, be able to identify those problans that can be solved by the use of corrosion inhibitors. Second, the economics involved mnst be considered (i.e., whether the loss due to corrosion exceeds the cost of the inhibitor and the maintenance and operation of the attendant injection systen). Third, the compatibility of inhibitors with the process being nsed must be considered to avoid adverse effects such as foaming, decreases in catalytic activity, degradation of another material, or loss of heat transfer (Klechka 2001). Finally, the inhibitor mnst be applied under conditions that produce maximum effect. 

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