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621.
J. B. Maynard W. N. Sanders 《Journal of the Air & Waste Management Association (1995)》2013,63(7):505-510
The quantitative data obtained with a capillary GLC method, which is used to determine the individual C3-C12 hydrocarbons in full-range motor gasolines, have been employed in a computer program to calculate the hydrocarbon composition of the vapor in equilibrium with a gasoline at 100°F, as well as the equilibrium vapor-pressure of the gasoline at that temperature. The method used for computation is similar to that previously described by McEwen, assuming the gasoline to behave as an ideal liquid. Also calculated is the potential atmospheric reactivity of this equilibrium vapor relative to that from other gasolines when specific reactivity weighting factors for the individual hydrocarbons are employed. Calculated total vapor-pressure data agree well with experimental Reid vapor-pressure data obtained for typical premium-grade gasolines. Definite differences were observed in the relative potential atmospheric reactivities calculated at 100°F for the equilibrium vapors from the test gasolines. 相似文献
622.
A. C. Costonis W. A. Sinclair 《Journal of the Air & Waste Management Association (1995)》2013,63(11):867-872
In a study of the ozone-induced needle blight of eastern white pine in central New York, acute injuries naturally induced on field trees during a year of relatively low ozone concentrations (1 966) were compared with injuries induced during a year of higher concentrations (1967). Injuries were more frequent and severe and were associated with higher mean ozone concentrations in 1967 than in 1966. Characteristic symptoms were induced on foliage of pine branches exposed to controlled doses of ozone as low as 7 ± 1 pphm for four hours or 3 ± 1 pphm for 48 hours. Such doses were equalled or exceeded two and four times, respectively, in the field during the 1 967 season. Ozone sensitivity of pine needle tissue was increased by fumigation in atmospheres containing water mist. High concentrations of ozone (40-60 pphm) caused general injury of foliage of both ozone-susceptible and resistant trees; the symptoms were unlike those found in the field or caused by fumigation with low concentrations of ozone. 相似文献
623.
M. Boulerice W. Brabant 《Journal of the Air & Waste Management Association (1995)》2013,63(6):432-434
Since 1966, the Division of Laboratories of the Department of Health of the City of Montreal is carrying on measurements of gaseous pollutants. In order to efficiently use the technical staff that our administrators wanted to devote to the fight against air pollution, a new lead dioxide support for the determination of sulfur dioxide has been devised. The preparation of candies according to the standard method requires much time and skill from the operator, whereas the technique that is proposed is rapid, easy, and provides plates of a high degree of uniformity. A technician with little experience can coat a great number of plates per day with no difficulty. N. A. Huey working at the National Center for Air Pollution Control in Cincinnati published in the September 1968 issue of this Journal a new technique which consists of coating the inside of a plastic Petri dish with a PbO2 paste. His method also has the above mentioned advantages. The plates that are suggested allow a simplification of the preliminary work for several types of analyses such as gra-vimetry,1 colorimetry,3 turbidimetry,4,5 titrimetry,6 and nephelemetry.8 相似文献
624.
J. G. Wilson D. W. Miller 《Journal of the Air & Waste Management Association (1995)》2013,63(10):682-685
The application of a high-efficiency centrifugal type of separator to fluid bed catalytic cracking units is described in which most of the catalyst particles often lost to the atmosphere are concentrated into a small part of the stack gas (2%). A further separation can then be made on this small stream by an auxiliary separator which further concentrates the catalyst particle into 0.1% of the initia stream. Performance of the main and auxiliary separators are such as to reduce the loss of catalyst particles in the stack gas from 800 ppm to less than 60 ppm in a typical unit. Large amounts of power can be recovered by application of expander turbines to catalytic cracking plants employing this system of separation. 相似文献
625.
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627.
J.N. Driscoll A.W. Berger J.H. Becker J.T. Funkhouser J.R. Valentine 《Journal of the Air & Waste Management Association (1995)》2013,63(2):119-122
The nitrate ion selective electrode was investigated as an alternative approach to the present colorimetric determination of nitrate resulting from oxidative absorption of nitrogen oxides from combustion effluents. The electrode offers advantages of speed and relatively simple experimental procedure. Replicate measurements of 10?4–10?2M nitric acid solutions using bracketing standards show that the electrode approach is capable of good precision (coefficient of variation = ±4%). Comparison of a method utilizing the nitrate electrode with the more laborious phenol disulfonic acid method for the measurement of nitrogen oxides in both oil and gas fired combustion effluents showed agreement within 4% of the mean even in the presence of high levels of SO2. The correlation coefficient found for PDS vs nitrate electrode is 0.987. 相似文献
628.
J.R. Brough W.A. Carter 《Journal of the Air & Waste Management Association (1995)》2013,63(3):167-171
The body of information presented in this paper is directed to design engineers, operating management and others who may be concerned with the prevention of atmospheric emissions from electric arc steelmaking furnaces. Inland Steel Co. has recently begun operating its first electric furnace shop. Air pollution control equipment for the shop was installed to meet or exceed the legal requirements of applicable air pollution ordinances and regulations. General shop production requirements were established at 100 tons of steel per hour (maximum) to meet sales forecasts and intermediate production facility requirements. Conventional swing roof furnace design was selected for the pair of furnaces in the shop. 相似文献
629.
V. Withstandley W.J. Moroz G.W. Anderson 《Journal of the Air & Waste Management Association (1995)》2013,63(9):571-573
A portable, battery-operated, electro-optical dust analyzer operating on the principle of light scattering from individual dust particles in air drawn through a high-intensity light field has been developed for monitoring dust levels where external power may be unavailable. The instrument counts and size-discriminates airborne particles over two size ranges upwards of 0.3 microns with immediate readout. A dilution mechanism permits analysis of particulate concentrations as high as 2400 particles/cm3 on each channel. The self-contained Ni-Cd batteries are rechargeable. Total weight, including batteries and all components, is approximately 14 Ib. Total power used, mainly for pumping a filtered air sheath at 300 cm/sec and for the light source, is less than 34 watts. Another unique feature is the flow system designed for turbulence suppression. Electronic calibration in terms of number of particles/cm3 for each size range is accomplished in the laboratory by means of a pulse generator with respect to which the readout indicator is calibrated for count. The input voltages to the pulse-height discriminators are appropriately attenuated for various pulse amplitudes simulating the output of the light-sensitive pickup, a photomultiplier tube.Pulse height as a function of particle size was measured for polystyrene latex beads ranging from 0.3 to 2 microns in diameter. Good correlation is obtained with results from commercial analyzers. Field surveys have been undertaken with the CAES prototype analyzer at various sites in central Pennsylvania and at numerous sampling points within the cities of Pittsburgh and Philadelphia. Particulate concentrations as high as 1400 particles/ cm3 have been measured at a coal cleaning plant. 相似文献
630.
W. Siu D.A. Levaggi L. Potter R. Martin M. Feldstein 《Journal of the Air & Waste Management Association (1995)》2013,63(10):636-638
The tape samplers using lead acetate impregnated paper tapes for continuous hydrogen sulfide sampling are subject to a number of errors which can throw considerable doubt on the accuracy of H2S concentrations being measured. Some of the errors have been minimized with a change in the humidification system and a reduction of the lamp intensity in the optical system. 相似文献