Environmental degradation problems

Because of this environmental degradation problem, it is difficult to obtain clean high-Tc superconductor surfaces, a key element for both electrochemical and electronic applications. However, a bulk ceramic superconductor sample can be renewed simply by polishing its surface. Such treatments have been shown to dramatically improve the electrochemical performance of YBa Cu307- electrodes [19]. However, thin films of YBa Cu307- do not lend themselves to this type of treatment. One technique that has been employed to improve the surface of old or damaged thin films of... 

During World War II, copious quantities of ordnance were lost into the harbor at Halifax, Nova Scotia. Decades later, these UUXO now present a significant environmental contamination problem. Studies conducted on this ordnance by Sandia National Laboratories [1] suggest that there may be sufficient concentrations of explosive chemical signature compounds emanating from UUXO to enable detection with chemical sensors. Some UUXO in Halifax Harbor have been shown to produce parts-per-billion levels of explosives in the water near the ordnance. In addition to the parent explosive compound (TNT), other explosive-related compounds such as 2,4-dinitrotoluene (2,4-DNT) were detected, as were degradation products of TNT such as 4-amino-2,6-dinitrotoluene (4-ADNT), and... 

The direct-oxidation systems are specific to hydrogen sulfide other sulfur species are apparently not attacked. Solution degradation problems may be caused by thiosulfate formation as well as thiocyanate formation (if HCN is present in the gas to be treated). Solution regeneration techniques have been developed to attempt to minimize the impact of these effects. The systems must be operated with caution, in some cases, the solutions contain species that are considered toxic or environmentally hazardous. 

Despite the severity of the problems associated with environmental degradation of mechanical properties, it is only recently that the ceramic composites community has begun to address them. In the following section, some of the approaches that attempt to inhibit the adverse effects of service environments are discussed for specific composite systems, and the relative effectiveness is assessed. 

Implementation of green chemistry education at the undergraduate level is key to adopting more sustainable practices and hence a more sustainable society 4), This education should be for both science and non-science majors. While certainly those students who are science majors may have a direct route to action in applying green chemistry principles in both research and development, nonscience majors can also benefit since they become aware of the importance of sustainable practices, learn about positive every-day habits, and come to realize that the chemical industry, which in the past (and even currently) was viewed as a major contributor to environmental degradation, is also part of the solution to the problem. 

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