Cycle analysis actual

According to r] = l-Rf the efficiency of the ideal Otto cycle increases indefinitely with increasing compression ratio. Actual engine experiments, which inherently include the real effects of incomplete combustion, heat loss, and finite combustion time neglected in fuel-air cycle analysis, indicate an efficiency that IS less than that given by r =l-R when a = 0.28. Furthermore, measured experimental efficiency reached a maximum at a compression ratio of about 17 in large-displacement automotive cylinders but at a somewhat lower compression ratio in smaller cylinders. 

The thermodynamic analysis of an actual Otto cycle is complicated. To simplify the analysis, we consider an ideal Otto cycle composed entirely of internally reversible processes. In the Otto cycle analysis, a closed piston-cylinder assembly is used as a control mass system. 

BASF has published the results of a Life-Cycle Analysis environmental study of the commercial manufacturing process for Lupranol Balance 50 polyol [151]. The study indicates a positive trend on the environmental impact of manufacturing the polyols by the new process. The actual impact of the current offering is difficult to gauge fi om this study, since in some cases the theoretical improvements... 

The assumptions that the future transition will be driven by fair market rules are somewhat at variance with the present situation. On one hand, there are hidden subsidies in many regions (e.g., to fossil and nuclear energy, where society pays for environmental and health impacts and assumes the responsibility for risk-related events), and on the other hand, monopolies and generally differences in size and power of the energy industries involved in different technologies make the actual price setting likely not to follow those prescribed by the life-cycle analysis in a fair market philosophy. 

The short summary of the life-cycle method preceding the actual analyses is necessary, because life-cycle analysis is not a standard calculation. In the literature, one finds various definitions ranging from restricted net energy analyses over environmental impact studies to the full consideration of both environmental and social impacts. It is the latter methodology, more fully described in Sorensen (2004a), which will be employed here. 

The actual work required for making a life-cycle analysis and assessment of a technology such as fuel cells may be summarised in the following way ... 

Finally, the conversion of the primary metal into the product and the form which are actually utilized in the battery system should be considered. For example, the electrode materials in lead acid batteries are normally cast lead or lead-alloy grids. The materials utilized in NiCd batteries are cadmium oxide and high surface area nickel foams or meshes. Technically, all of these factors should be considered to produce a detailed life cycle analysis. However, again, these differences are generally quite small compared to the principal variables - composition, performance and spent battery disposal option. 

Determining the impact assessment requires classification of each impact into one of these categories, characterization of the impact to establish some kind of relationship between the energy or materials input/output and a corresponding natural resource/human health/ecological impact, and finally the evaluation of the actual environmental effects. Many life cycle analyses admit that this last phase involves social, political, ethical, administrative, and financial judgments and that the quantitative analyses obtained in the characterization phase are only instruments by which to justify policy. A truly scientific life cycle analysis would end at the characterization phase, as many of the decisions made beyond that point are qualitative and subjective in nature. 

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