Carol L. Jones

Effects of cellulose, hemicellulose and lignin on thermochemical conversion characteristics of the selected biomass

The objective of this study was to investigate effects of biomass constituents (cellulose, hemicellulose and lignin) on biomass thermal decomposition and gas evolution profiles of four biomass materials. Switchgrass, wheat straw, eastern redcedar and dry distilled grains with solubles (DDGS) were selected as the biomass materials. No significant difference was observed in the weight loss profiles of switchgrass, wheat straw and eastern redcedar even though their cellulose, hemicellulose and lignin contents were considerably different. The weight loss kinetic parameters were also not significantly different except for activation energy of the eastern redcedar. However, biomass composition did significantly affect gas evolution profiles. The higher contents of cellulose and hemicellulose in switchgrass and wheat straw may have resulted in their higher CO and CO(2) concentrations as compared to eastern redcedar. On the other hand, higher lignin content in eastern redcedar may have resulted in significantly its high CH(4) concentration.

Scenario optimization modeling approach for design and management of biomass-to-biorefinery supply chain system.

The aim of this study was to develop a scenario optimization model to address weather uncertainty in the Biomass Supply Chain (BSC). The modeling objective was to minimize the cost of biomass supply to biorefineries over a one-year planning period using monthly time intervals under different weather scenarios. The model is capable of making strategic, tactical and operational decisions related to BSC system. The performance of the model was demonstrated through a case study developed for Abengoa biorefinery in Kansas. Sensitivity analysis was done to demonstrate the effect of input uncertainty in yield, land rent and storage dry matter loss on the model outputs. The model results show that available harvest work hours influence major cost-related decisions in the BSC.

Estimating Water Stress in Plants Using Hyperspectral Sensing

The ability to estimate plant water content may provide valuable information to environmental and irrigation system managers to relieve dehydration symptoms and prevent permanent growth and production damage. A portable spectroradiometer was used to gather hyperspectral reflectance data from three plant species (corn, spinach and snap beans) grown in a greenhouse and subjected to different watering conditions to instigate different levels of moisture deficiency. Spectral bands at 950-970, 1150-1260, 1450, 1950, and 2250 nm and five indices (WI, NDVI, SIPI, fWBI, and WI/NDVI) were analyzed to determine the best method of nondestructively estimating plant water content. In corn and snap beans, the 1450 nm band data provided the best estimate (r2 = 0.67 and 0.50). In spinach, reflectance data from the 950-970 nm bands were the most useful (r2 = 0.94).

Sonar and Digital Imagery for Estimating Crop Biomass

Ultrasonic distance sensing has been used extensively to detect proximity and distance to objects. Digital imagery can be used to estimate vegetative coverage. The product of plant height resolved through ultrasound distance sensing and top view surface area determined through digital imaging analysis was used to estimate plant biomass. This study used ultrasound and digital imagery to estimate biomass in corn, snap beans, and spinach. Strong correlation was found between actual biomass and estimated biomass in corn and spinach. (r2=0.85 and 0.84). Less accuracy was achieved in estimating bean biomass. NDVI alone and the product of NDVI and height were also considered as possible estimators of biomass.

Characteristics and Compositional Variation in Round and Square Switchgrass Bales Under Different Storage conditions

Storage losses in large round and square bales of switchgrass were measured for various outside and inside storage methods. After 3 months in storage, no significant change in dry matter was observed between the treatments. Significant changes in dry matter content were observed after 6 months in storage with highest loss occuring in square bales stored outside and unprotected from the ground. Significant difference was observed in covered and uncovered treatments in dry matter loss and moisture content. After 6 months in storage, average moisture content increased by 204% in uncovered square bales and 57% in uncovered round bales. Covered treatments were equally effective in protecting round and square bales from moisture accumulation and dry matter loss when compared to inside storage treatments. There was an increase in fiber portion of switchgrass bales after storage due to loss of extractives. A significant difference (P<0.0001) in lignin content was observed between covered and uncovered square bales. An increase in protein and ash content was also recorded, but no significant difference was observed between the treatments..

Chlorophyll Estimation Using Multi-spectral Reflectance and Height Sensing

Chlorophyll concentration relates strongly to the photosynthetic potential of a plant and subsequently to physiological and metabolic status of the plant. Chlorophyll is an indirect indicator of nitrogen status and is used in optical reflectance-based variable rate chemical application technology. This research investigated a non-destructive method of determining chlorophyll content and concentration at the individual plant level in spinach. A multi-spectral imaging system was used to determine spectral reflectance and to estimate top-view surface area. An ultrasonic distance sensor provided vegetation height estimates. Surface area estimates and height data were combined to estimate plant biomass. The relationships between reflectance, estimated biomass, and laboratory measured chlorophyll content and concentration were investigated. The product of biomass estimate and normalized difference vegetative index (NDVI680) provided the best estimate of chlorophyll content per plant (r2 = 0.91) while estimates of chlorophyll concentration per unit leaf mass were poor (r2 = 0.30).

Effect of preprocessing and compressed propane extraction on quality of cilantro (Coriandrum sativum L.)

Dehydration leads to quality defects in cilantro such as loss in structure, color, aroma and flavor. Solvent extraction with compressed propane may improve the dehydrated quality. In the present study, effect of drying temperature, particle size, and propane extraction on color, volatile composition, and fatty acid composition of cilantro was evaluated. Cilantro was dehydrated (40°C or 60°C), size reduced and separated into three particles sizes, and extracted with compressed propane at 21-27°C. Major volatile compounds found in dried cilantro were E-2-tetradecenal, dodecanal, E-2-dodecenal, and tetradecanal. Major fatty acids were linoleic acid and α-linolenic acid. Drying at 60°C compared to 40°C resulted in better preservation of color (decrease in browning index values) and volatile compounds. Propane extraction led to a positive change in color values and a decrease in volatile composition, oil content, and fatty acid composition.

Electrolyzed Water Generated Using a Circulating Reactor

Abstract Electrolyzed water offers several advantages over other sanitizers for sanitation of both food contact and non-contact surfaces. However, current electrolyzed water-generating process has low fluid output. To overcome such limitations, a circulating electrolyzed water-generating system has been developed in this study. The effects of NaCl/HCl concentration and electrolysis time were investigated. The free chlorine form (HClO and ClO–) of circulating electrolyzed water, and NaClO with the available chlorine concentrations of 50, 100, 200 mg/L were analyzed by using an ultraviolet spectrophotometer. The results show that the main chlorine form was HClO when the pH of solution was 6.44–6.53. The only ClO– in NaClO solutions when the pH of solution is 11.90. With the dilution of circulating electrolyzed water, the HClO concentration decreased while its proportion account for total available chlorine concentration increased (from 56.99% to 74.29%). The results indicated the potential application of diluted circulating electrolyzed water with high available chlorine concentration. The developed circulating electrolyzed water system in this study could be considered as a potential sanitizer due to its high stability, strong antimicrobial activity with high concentration of HClO and minimized equipment requirements for production.

Canopy Spatial Distribution and Identification Using Hyperspectal Data in Winter Wheat

Winter wheat varieties (Triticum aestivum L.) with different leaf angle distributions (LADs) were used in this experiment. Results showed that varieties with planophile LADs had leaf orientation values (LOVs) ranging from 25.12 to 40.33, whereas varieties with erectophile LADs had LOVs ranging from 67.5 to 73.25. Canopy spectral reflectance was measured using a ground‐based spectroradiometer. Correlation analysis indicated that LOV affected canopy spectra more than leaf area index (LAI) before the jointing stage. The LAI had the greatest effect after the ground was nearly completely covered. Discriminant analysis showed that simultaneous measurements of normalized difference vegetation index (NDVI) and cover can differentiate LADs in those wheat varieties with similar population magnitude at the jointing stage. In addition, by using increments of the canopy spectral reflectance at different growth stages, the planophile varieties with low LAIs can be differentiated from the erectophile varieties with high LAIs, which cannot be achieved using NDVI and cover. Using ΔR890 as the reflectance increment of booting stage and jointing stage and R890 as the reflectance of 890‐nm energy at the jointing stage, different varieties presented distinctly different scatter plot representations (X = ΔR890, Y = R890). This analysis also indicted that varieties with different LADs can be clustered and identified qualitatively in the plot despite their population magnitude, also validated by discriminant analysis.

Ozone Fumigation of Stored Grain; Closed-loop Recirculation and Rate of Ozone Consumption

Research using ozone gas as a fumigant has shown promise in controlling stored grain insect pests. In addition to being toxic to insects, ozone gas is unstable and decays naturally into diatomic oxygen and must be continually replenished to maintain entomologically lethal concentrations in the grain mass. This two-part study quantifies the rate of ozone gas decay encountered in typical grain storage environments. From this, ozone generation capacity can be modeled. A pilot study was conducted in a commercial steel grain bin filled with 13.6 tonnes of hard red winter wheat. The bin was equipped with a closed-loop recirculation system to capture and reuse ozone gas that had passed through the grain. A second laboratory study was conducted on 55 kg samples of wheat and corn to determine the rate of ozone decay in different grains at different fumigation temperatures. With previously untreated grain samples, initial ozone decay is high. After a passivation period that ranged from 53.5 to 84.7 h, the decay rate reached steady state. The half-life of ozone ranged from 122 s in grade 4 wheat to 242 s in grade 2 wheat. High foreign matter content in wheat significantly increased the rate of ozone decay. Results show that the rate of ozone decay in wheat and corn was not significantly affected by temperature in the range where fumigations are typically done.