This paper gives the rules of oscillations of two classes of neutraldifferential equations with forced terms, and some oscillation criteria undercertain conditions are presented according to the equations having diffe...This paper gives the rules of oscillations of two classes of neutraldifferential equations with forced terms, and some oscillation criteria undercertain conditions are presented according to the equations having differentcharacters.展开更多
Previous research on wet scrubbers has only studied highly acidic scrubbing solutions because of their high ammonia capture efficiencies; however, the high acidity created practical problems. Lower acidity solutions w...Previous research on wet scrubbers has only studied highly acidic scrubbing solutions because of their high ammonia capture efficiencies; however, the high acidity created practical problems. Lower acidity solutions would reduce corrosion, maintenance, and cost; however, designers may need to use strategies for increasing scrubber effectiveness, such as using lower air velocities. The objective of this studywas to determine if a spray scrubber with slightly acidic and higher p H scrubbing solution （pH from 2 to 8） could effectively remove NH3 from NH3 laden air （such as animal building exhaust air）, and also collect this valuable resource for rater use as a fertilizer. A bench-scale spray wet scrubber treated 20 ppmv NH3/air mixture in a countercurrent contact chamber. First, the solution pH was varied from 2 to 8while maintaining constant air velocity at 1.3 m. s-1. Next, air velocity was increased （2and 3 m.s-1） while solution pH remained constant at pH6. At 1.3 m.s -1, NH3 removal efficiencies ranged between 49.0% （pH8） and 84.3% （pH2）. This study has shown that slightly acidic scrubbing solutions are a practical means of removing ammonia from air especially if the scrubber is designed to increase collisions between solution droplets and NH3 molecules. The NH3 removed from the air was held in solution as NH4＋ and accumulates over time so the solution should be an excellent fertilizer.展开更多
文摘This paper gives the rules of oscillations of two classes of neutraldifferential equations with forced terms, and some oscillation criteria undercertain conditions are presented according to the equations having differentcharacters.
文摘Previous research on wet scrubbers has only studied highly acidic scrubbing solutions because of their high ammonia capture efficiencies; however, the high acidity created practical problems. Lower acidity solutions would reduce corrosion, maintenance, and cost; however, designers may need to use strategies for increasing scrubber effectiveness, such as using lower air velocities. The objective of this studywas to determine if a spray scrubber with slightly acidic and higher p H scrubbing solution （pH from 2 to 8） could effectively remove NH3 from NH3 laden air （such as animal building exhaust air）, and also collect this valuable resource for rater use as a fertilizer. A bench-scale spray wet scrubber treated 20 ppmv NH3/air mixture in a countercurrent contact chamber. First, the solution pH was varied from 2 to 8while maintaining constant air velocity at 1.3 m. s-1. Next, air velocity was increased （2and 3 m.s-1） while solution pH remained constant at pH6. At 1.3 m.s -1, NH3 removal efficiencies ranged between 49.0% （pH8） and 84.3% （pH2）. This study has shown that slightly acidic scrubbing solutions are a practical means of removing ammonia from air especially if the scrubber is designed to increase collisions between solution droplets and NH3 molecules. The NH3 removed from the air was held in solution as NH4＋ and accumulates over time so the solution should be an excellent fertilizer.
