LEADER 00000nam  2200349   4500 
001    AAI3497059 
005    20121203122741.5 
008    121203s2011    ||||||||||||||||| ||eng d 
020    9781267169709 
035    (UMI)AAI3497059 
040    UMI|cUMI 
100 1  Larbi, Peter Ako 
245 10 Development of a model to predict spray deposition in air-
       carrier sprayer applications 
300    192 p 
500    Source: Dissertation Abstracts International, Volume: 73-
       06, Section: B, page:  
500    Adviser: Masoud Salyani 
502    Thesis (Ph.D.)--University of Florida, 2011 
520    A simulation model was developed to predict on-target 
       spray deposition when using an airblast sprayer. It was 
       developed as a compartment model where, at a discrete 
       location in the sprayer's travel direction, the plume or 
       spray cloud is handled as passing through several 
       connected compartments of equal thickness but increasing 
       cross section, in the direction of application. With this 
       approach, the spaces between the sprayer and tree and 
       within the canopy were divided into small elements to 
       achieve the needed simplification for simulation purposes.
       The model, which accounts for evaporation, drift, and 
       ground deposition, simulates spray mass dispersion, 
       assuming no slip between spray droplets and airstream and 
       no contribution to sprayer air velocity from spray 
       droplets. The tree canopy equations account for foliage 
       distribution within a canopy in the direction of spray 
       application, which simultaneously represents resistance to
       spray transport resulting in deposition. With the 
       incorporation of maximum deposition, it is possible to 
       account for spray runoff from leaves. Two field 
       experiments were conducted to validate the model in two 
       parts, namely: dispersion and deposition. The dispersion 
       experiment setup consisted of a Polyvinyl Chloride pipe 
       structure that provided a grid of five target distances 
       from sprayer outlet and four sampling heights. Absorbent 
       paper targets were used to sample airborne spray from a 
       conventional airblast sprayer. In the deposition 
       experiment, twenty 3-tree plots in an orange grove were 
       sprayed and leaves sampled from the middle tree on two 
       sampling lines at two sampling heights and four canopy 
       depths. Ground samples were also collected. In both 
       experiments, spray treatments consisting of combinations 
       of two nozzles (Albuz ATR Lilac and Albuz ATR Blue 
       nozzles) and two forward speeds (2.4 and 4.8 km/h) were 
       applied using a conventional airblast sprayer. In both 
       experiments, samples were analysed by fluorometry and the 
       total leaf area of each sample from the deposition 
       experiment measured with an area meter. The results showed
       good agreements between the model output and the 
       experimental data with best predictions in the first case 
       yielding modeling efficiency (EF) and correlation 
       coefficient (r) of 78% and 0.90 for airborne spray and 50%
       and 0.62 for ground deposits, respectively. The second 
       case yielded EF = 61% and r = 0.92 for canopy deposition, 
       but ground deposition data was overly under-predicted by 
       more than three orders of magnitude and was not considered
       appropriate. Despite shortcomings, the model has potential
       for meeting the set objectives, and has been implemented 
       in an expert system to assist spray applicators in making 
       decisions critical for efficient spray operations 
590    School code: 0070 
650  4 Applied Mathematics 
650  4 Engineering, Computer 
650  4 Engineering, Agricultural 
690    0364 
690    0464 
690    0539 
710 2  University of Florida 
773 0  |tDissertation Abstracts International|g73-06B 
856 40 |uhttp://pqdd.sinica.edu.tw/twdaoapp/servlet/