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Internal combustion (IC) engines are a major contributor to the total particulate emissions inventory, especially in urban areas. Recent epidemiological studies suggesting links between fine particles and negative health effects have sparked an increased interest in this subject. While particulate emissions from IC engines have been the focus of research for many years, a great deal of information crucial to our understanding of this subject still remains unknown. In this paper the authors address some of these unknowns, focusing primarily on the process and consequences of aerosol dilution strategy. The thermodynamics of dilution are considered, and the inadequacy of conventional constant-volume sampling dilution tunnels for ultrafine particle characterization are demonstrated using experimental data. Finally, time-resolved data demonstrating the variation in concentration of pollutants in a vehicle moving in traffic are used as an example of the difficulties in setting legislation aimed at controlling exposure to ultrafine particles.

We saw (Section 4.4) that CO₂ (carbon dioxide) reacts with quicklime (calcium oxide) in water at 25°C, under 1 atm generating calcium carbonate or limestone (CaCO₃). The process is a sequence of two reactions (4.14) and (6.1):

The role of chirality in the theories that determine the origin of life are reemphasized—in particular the fact that almost all amino acids utilized in living systems are of the L type. Starting from Z⁰ interactions, I speculate on an explanation of the above fact in terms of quantum mechanical cooperative and condensation phenomena (possibly in terms of an e–n condensate where the e–n system has the same status as Cooper-pairing), which could give rise to second-order phase transitions (including D to L transformations) below a critical temperature T_c. As a general rule, T_c is a low temperature. From this, it is conceivable that the earth provided too hot a location for the production of L amino acids. I suggest laboratory testing of these ideas by looking for the appropriate phase transitions.

Wall condensation phenomenon of car body of the high-speed rail has a great influence on train operation safety and air conditioning load. However, due to the complexity of condensation mechanism, it is difficult to analysis car wall condensation process from pure theory. Experiment method is adopted in this paper to study the phenomenon, and the corresponding results are obtained, which is beneficial to the optimization design and running of car.