@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} }