Investigation of Low Cost Solar Drying of Apricots for Tajikistan

Dried apricots are one of Tajikistan’s major export products. The country wants to expand its production in the southern region. However, the producers don’t have the expertise needed to produce dried apricots that meet the quality requirements of the European Union and other potential export markets. Local producers in southern Tajikistan would benefit from improvements in methods of applying sulfur and drying the apricots. This would allow them to gain a share of global markets. Methods that were studied include sulfur treatment prior to drying and approaches for rapidly drying the apricots while preventing contamination. Because the project has just started, efforts are focused on developing the methods to determine the quality of apricots. Preliminary tests were conducted on dried apricots purchased from local stores or on fresh apricots dried by project personnel. These will serve as standards against which Tajikistan dried apricots will be compared. Quality factors evaluated included color, microbial content, sulfur content, water activity, percent soluble solids, and moisture content. This paper reports results of preliminary quality tests conducted on dried apricots purchased from stores in West Lafayette and Lafayette, Indiana. To prepare for future studies, thin layer drying tests were conducted on fresh apricots purchased from local stores and apricots grown in Michigan which were obtained from a contact in the Lafayette Farmer’s Market. These apricots were treated and dried in a thin layer dryer at three different temperatures to better understand factors that affect drying rate. Quality parameters of these dried apricots were also determined

Three-dimensional transient heat, mass, momentum, and species transfer in the stored grain ecosystem: Part I. Model development and evaluation

A 3D transient heat, mass, momentum, and species transfer model for the stored grain ecosystem was developed using the finite element method. Hourly weather data such as ambient temperature and relative humidity, solar radiation, and wind speed were used as input in the model. The 3D model has different components that predict grain temperature and moisture content, dry matter loss, insect population, and species (CO2 and fumigant) concentration. The 3D model was evaluated using linear elements with three different numbers of nodes and quadratic elements with three different numbers of nodes. The accuracy of prediction for each category was evaluated using the observed and predicted temperature values. The linear model with 384 nodes and the quadratic model with 415 nodes were found to be the best based on the lowest standard error compared to other combinations. Four different time discretization schemes were used to evaluate model accuracy over time. The Crank-Nicolson time discretization scheme was found to be the best of the four

Fine material in grain

Fine material in grain: an overview / Richard Stroshine -- Factors that affect the costs of fines in the corn export market / Lowell D. Hill, Mack Leath -- Effects of fine material on mold growth in grain / David B. Sauer, Richard A. Meronuck, John Tuite -- Effects of fine material on insect infestation: a review / Paul W. Flinn, William H. McGaughey, Wendell E. Burkholder -- Reducing or controlling damage to grain from handling: a review / Charles R. Martin, George H. Foster -- Evaluating grain for potential production of fine material - breakage susceptibility testing / Steven R. Eckhoff -- Genotypic differences in breakage susceptibility of corn and soybeans -- M. R. Paulsen, L. L. Darrah, R. L. Stroshin

Mathematical Analysis of Pressure Chamber: EFFLUX EXPERIMENTS

The Scholander pressure chamber is one of several devices used to study the water relations of green plants. For field work it can be used to rapidly measure leaf water potential, and for laboratory studies it can be used to determine the turgor and osmotic components of plant water potential.A series of experiments were conducted on wheat leaves. A leaf was cut from the plant and placed in the cylindrical chamber so that its cut end protruded through an air-tight seal. When the chamber was pressurized to several atmospheres, water appeared at the cut end. When the pressure was increased several more atmospheres, water flowed from the cut end of the leaf for 10 to 40 minutes. The total efflux was dependent on the water potential of the leaf. Efflux curves for the experiments were drawn by plotting the total water expressed as a function of time after the pressure increase. The total efflux was dependent on the water potential of the leaf. This dissertation is an experimental and mathematical analysis of the efflux curves