No abstract

Recent results from climate models have led to the prediction that a global warming due to increasing atmospheric CO2 is now imminent, if it has not already occurred. In an effort to develop more definitive information on this question, a detailed review has been conducted of prior efforts to unravel climatic change from the various types of recorded observational data available. Most of the more definitive of the prior analyses—along with evaluative comments by the various authors—have been assembled herein. There appears little doubt that the average surface air temperature of at least northern hemisphere has been increasing since the beginning of recorded data with most of the warming occurring in a brief period circa 1920. The fragmentary early data suggest significant cooling prior to 1883 such that 25–50% of the subsequent warming may represent a return to earlier levels. Whether the overall warming constitutes a climate change remains an unresolved problem, as does the cause of the warming.

No abstract

A number of computer programs have been developed for identifying low resolution mass spectra through search of an extensive library file. One set of programs used as a disagreement criterion the sum of the absolute values of the differences in peak height levels when peak height was encoded to 2, 8, or 101 234 levels at each nominal mass. Another program employed the maximum coincidence of the top N peaks. The programs weré tested using 125 unknowns and the recognition performances were compared. The maximum coincidence criterion was significantly poorer in recognition performance than the other techniques which increased In reliability as the number of levels increased. However, even the two-level system attained very high reliability. Since computer requirements and economic costs are likely to be minimal for this case, it might suffice for many applications.

No abstract