Rate data for the decomposition of ammonia in a glow-discharge flow system were obtained at 1.7 mm Hg and several current levels. Pure ammonia at 25°C was fed continuously to the reactor at different flow rates. The reaction products were observed using both optical spectroscopy and gas chromatography. A reaction mechanism for the rate steps which fits the data well is proposed. The principal feature of the mechanism is the use of two simultaneous reactions for NH2 combination. One leads to N2H4 and the other to NH and NH3.

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The effect of gamma radiation on the sedimentation and degradation of corn starch sols has been investigated for doses between lo2 and 106 rad. No enhancement of the sedimentation during a 1-hour period has resulted from the irradiation. For the higher doses, radiation has decreased the degree of sedimentation although a progressive decrease in turbidity resulted as the dose increased. The observed reduction of turbidity has been attributed to progressive degradation of the starch with increased d o s s . The steps and the degree of degradation have been investigated spectrophotometrically using an iodine indicator and are analogous to those noted in chemical degradation studies. n recent years, considerable emphasis has been placed I on the development of improved methods for sewage treatment. Of particular interest to several investigators has been the possibility of using ionizing radiation to aid in coagulation and sedimentation of colloidal particles. Reported results have, however, indicated considerable variation and strongly suggest that additional research is required to establish the full potential of radiation treatment of sewage waters for the purpose of enhancing coagulation and sedimentation.Because of the complex and varied composition of sewage waters and the equally complex and varied sedimentation effects which radiation may induce, many investigators have chosen to work with clearly defined, often rather simple, systems in an attempt to isolate the significance of individual effects. This study is of such a nature and deals with the effects of gamma radiation on a common colloid, the corn starch sol.The study was initiated to confirm and expand upon the sparse experimental sedimentation data reported in the literature for this system (Unidynamics, 1960(Unidynamics, , 1961a(Unidynamics, ,b, 1962a(Unidynamics, ,b. 1963(Unidynamics, , 1964. However, the results obtained were at considerable variance with those in the literature. A closer examination of available information led to the establishment of two goals for this research study: the determination of the effect of gamma radiation on the sedimentation rate over a wide range of total dose, and the investigation of the degree of starch degradation resulting from irradiation.The effects of ionizing radiation on colloids have been studied for a variety of systems. In several cases, little or no perceptible effects on settling and precipitation were noted. These included studies of stannic oxide, bacterial and river suspensions, and ferric and aluminum oxide sols (Burrows, Corbett, et al., 1963). Investigations of ferric hydrate sols, arsenic sulfide sols, and mastic resin using radon also indicated no change for negative sols but did indicate faster flocculation of positive sols (Boutaric and Roy, 1933). In contrast, irradiation with x-rays enhances precipitation of b3th positively and negatively charged sols (Nanobashnili and Bakh, 1953, and gold sols flocculate after irradiation (Crowther Liebman et al., 1938, 1939. Accelerated sedimentati...