@article{abubakar_young_johnson_weeks_2003, title={Modeling moisture and chemical changes during bulk curing of flue-cured tobacco}, volume={46}, DOI={10.13031/2013.13935}, abstractNote={Mathematical models to predict moisture content, chlorophyll, starch, and reducing sugar concentrations were
developed as a function of curing variables like temperature, initial moisture content, airflow rate, time, and initial chemical
concentrations. The moisture removal model was based on a two–term (liquid and vapor) thin–layer drying equation, while
chlorophyll, starch, and respiration models were based on first–order rate equations. Several product parameters required
in secondary equations were determined through regression and comparison of root mean square errors. The models were
fitted to the experimental data collected during the first year of the experiments (1997) to determine the product parameters
by minimizing root mean square errors. The models were then verified using the experimental data obtained in the second
year of the experiments. The models will help predict effects of curing variables on rate of moisture removal and chemical
concentrations in the cured tobacco leaf. This information will contribute to the optimization of the curing process in terms
of process efficiency and product quality.}, number={4}, journal={Transactions of the ASAE}, author={Abubakar, Y. and Young, J. H. and Johnson, W. H. and Weeks, W. W.}, year={2003}, pages={1123–1134} }
@article{anderson_abubakar_young_johnson_1998, title={Pressure vs airflow characteristics through fresh intact and cut-strip tobacco}, volume={41}, DOI={10.13031/2013.17318}, abstractNote={Pressure versus airflow characteristics were determined for various densities and cut sizes of green tobacco
leaves with leaf surfaces oriented either parallel or perpendicular to the airflow. The flowrate measurement device
consisted of a fan, PVC pipe, orifice plate, sealing apparatus, and a plenum. Graphs of pressure gradient versus
superficial velocity showed a nearly linear log-log relationship. Three equations were used to fit the data: the power
equation, ASAE standard equation, and Ergun equation. The Ergun equation provided the best fit in most cases. Analysis
of variance of equation parameters with experiment variables showed that the pressure gradient was a function of the leaf
density squared. The only other factor affecting the pressure gradient was the leaf orientation. For a given velocity, leaves
oriented perpendicular to the airflow had a pressure gradient about 10 times greater than that of the leaves oriented
parallel to the airflow.}, number={6}, journal={Transactions of the ASAE}, author={Anderson, D. S. and Abubakar, Y. and Young, J. H. and Johnson, W. H.}, year={1998}, pages={1747–1753} }