A colorimetric quantitative analysis for di-n-octylphthalate and other aromatic esters has been developed which is capable of determining as little as 0.1 milligrams of an ester. This method is based on the formation of hydroxamic acid from esters using hydroxylamine hydrochloride in an alkaline medium. On the addition of an acidified solution of ferric per-chlorate, a red-colored complex of ferric hydroxamate is formed, proportionate in intensity to the weight of ester present. Mist composed of di-n-octylphalate droplets of 0.869 microns average diameter was removed from air at substantially atmospheric temperature and pressure by passing the air up through a bed of 150/200 mesh silica gel fluidized in a 2-1/4 inch glass column. Removal efficiency, defined as the percent (by weight) removal of the mist was substantially independent of the entering concentration over the range 0.765 to 0.965 milligrams of ester per cubic foot of air. For a given bed, removal efficiency improved with decreasing superficial gas velocity. Two bed weights were used, 13.25 grams per square centimeter and 25.35 grams per square centimeter, and it was found that the removal efficiency was practically in dependent of the bed weights. The maximum removal efficiency was 88.8% at a superficial bed velocity of 3.2 centimeters per second and a bed weight of 13.25 grams per square centimeter. The same mist was removed by passing the gas stream through various venturi nozzles with ports in the throat through which fine silica gel (150/200 mesh) entered by gravity and aspiration into the gas stream. For the venturi nozzles the removal efficiency generally increased with increasing velocities; however, the maximum removal efficiency obtained was only about 40%. It is shown that the behavior and collection efficiences obtained with the two devices can be satisfactorily explained if the fluidized bed is assumed to collect the aerosol particles by diffusional processes only, and the venturi tube, by inertial processes only, at least for aerosol particles of the size used in this work. The problem of efficient removal of aerosol particles in the range of 0.1 to 1.0 microns diameter has still not been solved in an economical manner for many cases of industrial importance. The removal becomes even more difficult when the aerosol particles are fairly uniform in size. The purpose of the present work was to conduct a preliminary testing of new devices which might be more efficient for small particles than those now commonly used. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Thesis (Ph. D.)--Stanford University. / Reprinted from the Journal of the American chemical society, v.29, p. 970-98; v.30, p. 915-46; v.32, p. 518-530.

No description available.

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1914. / The entire thesis text is included in file. Typescript. Illustrated by authors. Title from title screen of thesis/dissertation PDF file (viewed March 31, 2009)

University of Macau / Faculty of Science and Technology / Department of Electromechanical Engineering

Time variations of soiling index at three locations in central Montreal are analysed. The average week end reduction in smoke is about 20 percent. Readings adjacent to Mount Royal Park are reduced by nearly one half, but no attempt is made to separate out the effects of the Park acting as a smokeless zone, and the mountain acting as an obstacle to the wind flow. Data from the elevated location, together with visual observations, suggests that at night the smoke over the city is usually confined to a layer several hundred feet deep. A simple model is developed to consider the modification of stable air as it moves across a city acting as a heat and smoke source. An adiabatic mixing layer of increasing depth builds up due to the accumulation of heat. Applying this model indicates that half of the smoke in mid-winter is due to heating of buildings.

No description available.

The emissions, efficiency, and combustion chamber conditions of the Rayburn Prince 76, a clean-burning, hand-fired coal heater developed by the British have been studied. It was desired to determine if the downdraft design of the Prince would lead to low emissions when operated on American coals. Temperature and species concentrations were measured in the unit's secondary combustion chamber. Temperatures and gas residence times in the secondary combustion chamber were found to range from 440 to 1040°C and 15 to 40 ms, respectively. Little soot and volatile oxidation probably occurred in the chamber, due to the relatively low temperatures and short residence times. The emissions and efficiency of the heater were determined for operation on two bituminous coals at both high and low firing rates. The CO, NO_x, SO_x, and smoke emission factors were found to range from 38 to 120 g/kg, 1.2 to 5.8 g/kg, 3.3 to 5.4 g/kg, and 2.3 to 16 g/kg, respectively. The smoke emission factors for the Prince were found to be up to six times lower than those found using identical coals in updraft stoves. The overall efficiency of the unit was determined to range from 54 to 60%. The sensible energy losses were found to represent the majority of the total energy losses. / M.S.

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy