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INDUSTRIAL AND ENGINEERING CHEMISTRY
but the difference does not appear to be material), while the so values were calculated for each month of 1944 by taking the difference between the effective average of mean daily temperatures over monthly periods and the corresponding mean monthly temperatures. The twelve values of 63 thus obtained for each place were averaged to obtain a best value. Values of 64 were obtained by taking the difference between the effective average of mean monthly temperatures over the desired interval, usually 6 or 12 months, and the mean temperatures for the same periods. The consequences of these calculations were studied to establish some rather rough rules for estimating the values of the 6’s for other places where data are unavailable or where detailed calculations are not warranted. The values of 61 in Table V are not universally reliable. They were obtained in low latitude, low altitude desert, and might not apply at all well to summer arctic conditions or under continual cloudiness. It appears that they are reasonable for partly cloudy weather. High winds will reduce the value of &. Gasoline stored on ground covered by green vegetation should give a lower value than gasoline stored on bare ground; the latter is certainly the more common condition. The values of 82 given in Table V I should be generally applicable simply because the form of the daily air temperature cycle cannot vary widely. When data on daily air temperature range are not available, 62 may be estimated as follows: At coastal locations the daily air temperature range is only 10’ t o 15” F.; accordingly 82 is so small that it is not worth while to calculate it for such places, even given the data. A good value for humid low altitude “Continental” locations away from the moderating influence of the sea, such a s the Mississippi Valley, is 20” F. Continental locations having considerable altitude (say, 3000 feet) or low humidity will have a daily range of roughly 30” F., while values as high as 40” F. or, rarely, 50” F. will be found only when most or all of the factors of continental location, high altitude, low humidity, and special local terrain are present. Very hot places, which are rarely found outside of continental regions, may have a daily temperature range 5’ F. higher than would be otherwise expected. Values of & are small and rarely worth evaluating. Values of 64 are small for tropical stations, but mag be considerable in the temperate zone, particularly a t continental locations. Values of 64 are easily calculated, the data are available (16,16), and the operation is worth while in specific cases if there is any doubt as to its magnitude. 4. On the basis of all these considerations, values of the 6’s have been calculated or estimated for a number of representative stations outside of the United States. with emphasis on the hot places. Values for 6 2 and 6 3 were estimated on the basis of geographical and climatological considerations and in the light of the values obtained for domestic stations. There are a few exceptions, in the case of where eetimates were made directly from data on daily temperature range obtained by private communication with the Weather Bureau. Values of 64 were calculated in all cases from mean monthly temperatures by averaging the values for each of several individual years (the value resulting from effectively averaging long-term monthly means would have been slightly, possibly not significantly, smaller). These data, together with the effective gasoline temperatures derived from them for both domestic and foreign points, are summarized in Table X. Table X speaks for itself. Two places are shown which are hotter than Imperial-namely, Bagdad and Khartoum. A few locations omitted for lack of data may be even hotter. Massaua in Eritrea is a conspicuous example. By and large, though, there are few places on earth where effective gasoline temperatures will exceed those found in the Imperial Valley. Contrasted t o this, there are many places where effective gasoline temperatures will exceed 100”F. during the hot months and it appears that values below 90” F. are rather exceptional in the warmer half of the temperate zone. One notable exception was included in the table t o show the extreme effects of continental location: Verkhoyansk, Siberia, is known as having the coldest winters on earth, b u t its summers are moderate and this great seasonal contrast gives rise t o an extraordinary value for 84 for the year. Expressed in another way, this simply means that effective temperature in such a
Vol. 45, No, 9
location is determined almost entirely by the summer temperatures. I n contrast to this extreme continental site, there is a marine location, on South Georgia Island (latitude 54”13’S, longitude 36 “33’W), where mean monthly temperatures never fall below 28” F. and yet effective gasoline temperatures are less than 60” F. This results, of course, from its equable climate: a mean summer temperature of 38” F., winter temperature of 30” F., ahd a daily temperature range which is probably less than 10’ F. SUMMARY
Intensive data on air and gasoline temperature a t a field test site have been used t o predict gasoline degradation at the same place. The results have been found in agreement with the observed degradation. The procedure has been extended by the use of approximations based on condensed data on air temperature to predict the rate of gasoline degradation a t any place for which routine climatological data are available. LITERATURE CITED
(1) Alspaugh, >X. L., S . A . E . Journal, 54, 289 (1946). (2) Am. Inst. Physics, “Temperature, Its Measurement and Control in Science and Industry,” chapter by Larsen, D. E., p. 1099 ff., Kew York, Reinhold Publishing Corp., 1941. (3) Bolt, J. A., S.A.E. Journal, 56, 89-90 (October 1948). (4) Coordinating Research Council, Xew York, “Report on 1944 Desert Storage Tests on Aviation Gasolines with and without CS,” pp. 66, 67, June 1945. (5) Coordinating Research Council, New York, “Report on 1943 Desert Storage Tests on 80 Octane Number All-Purpose Gasoline Stability,” p. 84, September 1944. (6) Ibid., p. 89. (7) Ibid., p. 90. ( 8 ) Ibid., Appendix by Keyser, P. V., and Kuhn, W. E., pp. 154-97. (9) Coordinating Research Council, New York, “Report on 1944 Desert Storage Tests on Stability of 80 Octane Kumber AllPurpose Gasoline,” p. 98, March 1945. (10) Ibid., p. 100. (11) Luten, D. B., Jr., and Hedberg, Kenneth, “Temperature of
(12) (13)
(14) (15)
Stored Gasoline. 1943-1945 CRC Desert Storage Tests on Motor and Aviation Gasoline. Part 11. Effective Storage Temperatures of Gasoline,” New York, Coordinating Research Council, July 1952. Shepherd, C. C., Ibid., “Part 111. Actual Air and Gasoline Temperatures,” New York, Coordinating Research Council, July 1952. Shepherd, C. C., and Luten, D. B., J r . , Ibid., “Part I. Introduction.” Sherman, J., IXD. EKG.CHEM.,28, 1027 (1936). Smithsonian M i s c . Collections 79 (1927).
(16) Ibid., 90 (1934).
(17) U. S. Dept. Agriculture, “Climate and Man,” Year Book of Agriculture, p. 664, 1941. (18) U. S. Dept. Commerce, Weather Bureau, “Climatological Data.” (19) Walters, E. L., Proc. Am. Petroleum Inst., 27 (III),116 (1947). (20) Yabroff, D. L., and Walters, E. L., IND.EXG.CHEM.,32, 83 (1940). RECEIVED for review July 22, 1952. ACCEPTED June 5 , 1953. Based on experimental work and calculations done in conjunction with the wartime desert storage testing of gasoline, carried out under the direction of the Gasoline Additives Group, Motor Fuela Division, Coordinating Fuel Research Committee, Coordinating Research Council, Inc. The full report of temperature investigations (11-18) has recently been issued and is obtainable from the American Petroleum Institute.
Correction I n the article, “Basic Factors in Pilot Plant Work’’ [A. L. Conn, IND.ENG.CHEM., 45, 1625 (1953)], the figure captions are reversed.
Correctly, these should read:
Figure 1.
Steps in Commercializing a Research Idea
Figure 2. Pilot Plant Functions
