The solid substrate cultivation (SSC) process is often limited by rapid increases in temperature as a result of metabolic activity and poor heat transfer properties of the solid substrate. High temperatures can adversely affect microbial growth and product formation. Reduction of substrate temperatures is important for improved productivity, yet effective and efficient control of heat transfer in a deep-bed SSC reactor has proven difficult. An internal cooling water coil was incorporated into a deep-bed reactor system and evaluated for its ability to reduce substrate temperature. Three operating treatments were investigated: cooling water circulation whenever the center bed temperature was above 30 degrees C, timed cooling water operation on 10 min on/off intervals from the start of cultivation, and timed operation on 10 min on/off intervals after the expected start of microbial exponential growth. Enzyme yield, peak temperature, and net rate of metabolic heat accumulation within the substrate bed were measured during the cultivation of Trichoderma longibrachiatum on wheat bran for xylanase production. The cooling water reduced the temperatures observed in the substrate bed by 5 degrees C on average and was effective in decreasing the rate of heat accumulation in the bed. Within a 10 min time interval, the internal heat exchanger demonstrated a net decrease in heat accumulation at an average rate of approximately 0.5 degrees C/min. Despite the decrease in temperatures observed with the control strategies, the xylanase yields were not statistically different from the cultivations with no temperature control.

Grain handlers have responded to an increased use of specialty grain and the resulting need for grain segregation without the benefit of experimental data in the literature quantifying the commingling that may occur during grain handling. This study was conducted to evaluate the effects of handling equipment on commingling and residual grain at an average grain flow rate of 47 t h(-1) (1852 bu h(-1)) in the research elevator at the USDA-ARS Grain Marketing and Production Research Center in Manhattan, Kansas. Tests were done by first moving white corn through selected pieces of cleaned elevator equipment followed by moving yellow corn through the same equipment without any special clean out between the two operations. Commingling was calculated as the percentage of white kernels mixed in the yellow corn samples collected at selected time intervals during the second operation. Commingling was greater than 1% during no more than the first 38 sec and always decreased to less than 0.5% within the first metric ton of load (76 sec) for all tested equipment. The highest cumulative commingling for tests of one truckload (ca. 7.3 t) was 0.24% for the grain cleaner. Mean cumulative commingling values for the other handling equipment were 0.22%, 0.01%, and 0.18% for the weighing scale, grain scalper, and the combined effect of dump pit and boot, respectively. The residual grain obtained from cleaning the equipment after the test was highest at the elevator boot (120 kg), followed by the receiving pit (20 kg). The amounts of residual grain collected from the weighing scale, grain cleaner, and grain scalper were negligible (<1 kg) by comparison.

A non-intrusive survey method was developed that examined the relationships among spatial and temporal variations of soil water content, soil texture, and bulk electrical conductivity (EC(a)) in a 7.5 ha research watershed in southwestern Tennessee. Our goal was to identify areas that may exhibit rapid movement of subsurface moisture, as this is a precursor of offsite agrochemical migration. The survey protocol identified similar and dissimilar temporal variations in EC(a) patterns. Repeated spatial measurements of EC(a), starting at near field capacity and then progressing through the draining and drying process, supplied visually shifting EC(a) patterns that correspond to dynamic soil moisture variations and subsurface morphology transitions. We noted that spatial EC(a) patterns for a field remained somewhat analogous across data gathering events, shifting in relative amplitude along with seasonal moisture levels. For this study, we considered soil morphology constant over the short data acquisition interval, with short-term subsurface moisture variations as the parameter primarily influencing EC(a) changes. We inferred soil morphology as the major factor for EC(a) pattern similarity across time. Follow-up soil coring analysis along two separate low-to-high EC(a) transects supported this assumption for this site.

The Microgravity Pocket (MGP) was designed for continuous production of root crops in microgravity within a controlled environment. The MGP is intended to provide NASA with a "Salad Machine" to grow carrot and radish for consumption by astronauts. Attributes of the pocket system, include light weight; ease of planting, monitoring, and harvesting; no free water; and low energy requirements. The MGP system uses porous sheets of plastic to wick water to the plant roots, which are enclosed within a watertight pouch. An experiment was conducted growing carrot and radish root crops in a horizontal orientation adjacent to a water-cooled high-pressure sodium lamp. The hydrophilic property of the porous sheet provided nutrient solution to the root zone of the plants, but the small size of the pores prevented root growth into the sheet. The MGP was successful in growing both carrot and radish to harvestable size.

This research developed an effective and nondestructive method for inspecting the texture of guava fruit and highly sensitive indices of quality using an impact pendulum and discriminate analysis. Impact parameters calculated from the force-time curve, amplitudes, and spectra were used to reflect the variation in the texture of fruit during storage. Statistical discriminate analysis was conducted to determine the impact parameters and highly sensitive classification indices from combinations of parameters. Test results indicate that the two classifications by the indices, obtained from parameter sets of TA (force-time and amplitude spectrum) and AI (amplitude spectrum and imaginary part spectrum), were both on average over 80% consistent with the change in the maturity of the fruit, which was significantly more than the strength of the relationship with any single impact parameter, which yielded a classification accuracy of under 70%.

Phosphorus-based land application of swine manure slurry results in under-application of nitrogen (N), while nitrogen-based application leads to over-application of phosphorus (P). Significant amounts of P must be removed from swine manure to reduce P over-application, and at the same time, safely apply targeted amounts of N. This study compared three schemes of soluble orthophosphate (ortho-P) reduction from liquid swine nursery manure during batch aeration: (1) solids-liquid separation before aeration (pre-aeration solids-liquid, or PASL, separation), (2) solids-liquid separation in the middle of aeration (mid-aeration solids-liquid, or MASL, separation) and (3) no solids-liquid separation (control). Significantly more ortho-P was converted to non-soluble species with MASL separation (92%) than with either PASL separation (87%) or the control (84%). MASL separation also significantly improved the removal of total phosphorus (TP) in the sludge from the liquid after an overnight sedimentation process: 80%, 70%, and 66% for MASL separation, PASL separation, and control, respectively. Solids-liquid separation enhanced the maintenance of higher oxidation potentials (depicted by higher values of ORP in the separated manures than in the control) in the manure during the latter days of aeration, implying that substantial energy saving is possible for prolonged aeration of separated liquid manure. This is an important element in the post-aeration treatment for ensuring that P removed from the solution stays in the sludge and is not released back into solution, if removal of the sludge does not immediately follow scheduled aeration treatment.

A finite difference mathematical model was developed utilizing measured data to predict the temperature profile through a waterbed used in cow stalls. The model also predicts conduction heat flux from a cow lying down on the waterbed. Convection and radiation heat losses were determined from measured data. Conduction heat flux comprised 2.0 and 1.8 times that of convection and radiation, respectively. Because of limited contact area with the waterbed, conduction heat flow constitutes 19% of the total heat flow and is a small fraction of convection and radiation. Sensitivity analyses were conducted to determine effects of thermal conductivity of the surface material and fluid in the waterbed on conduction heat loss. Increasing the surface thermal conductivity by 100% increased conduction heat loss by 55%, while increasing the fluid thermal conductivity by 100% increased conduction heat loss by only 11%. Decreasing the water temperature from 27.1°C to 10°C by cooling the water in the waterbed at rates of 10, 15, and 20 kW/m 3 increased conduction heat flux by 174%, 200%, and 226%, respectively. It may be concluded that lying on waterbeds filled with chilled water may alleviate thermal heat stress of cows.

Inverse estimation of unsaturated soil hydraulic and solute transport properties has thus far been limited mostly to analyses of one-dimensional experiments in the laboratory, often assuming steady-state conditions. This is partly because of the high cost and difficulties in accurately measuring and collecting adequate field-scale data sets, and partly because of difficulties in describing spatial and temporal variabilities in the soil hydraulic properties. In this study, we estimated soil hydraulic and solute transport parameters from several two-dimensional furrow irrigation experiments under transient conditions. Three blocked-end furrow irrigation experiments were carried out, each of the same duration but with different amounts of infiltrating water and solutes resulting from water depths of 6, 10, and 14 cm in the furrows. Two more experiments were carried out with the same amounts of applied water and solute, and hence for different durations, on furrows with water depths of 6 and 10 cm. The saturated hydraulic conductivity (K(s)) and solute transport parameters in the physical equilibrium convection-dispersion (CDE) and physical nonequilibrium mobile immobile (MIM) transport models were inversely estimated using the Levenberg-Marquardt optimization algorithm in combination with the HYDRUS-2D numerical code. Soil water content readings, cumulative infiltration data, and solute concentrations were used in the objective function during the optimization process. Estimated K(s) values ranged from 0.0389 to 0.0996 cm min -1 , with a coefficient of variation of 48%. Estimated immobile water contents (theta(im)) were more or less constant at a relatively low average value of 0.025 cm 3 cm -3 , whereas the first-order exchange coefficient (omega) varied between 0.10 and 19.52 min -1 . The longitudinal dispersivity (D(L)) ranged from 2.6 to 32.8 cm, and the transverse dispersivity (D(T)) ranged from 0.03 to 2.20 cm. D(L) showed some dependency on water level and irrigation/solute application time in the furrows, but no obvious effect was found on K(s) and other transport parameters, most likely because of spatial variability in the soil hydraulic properties. Agreement between measured and predicted infiltration rates was satisfactory, whereas soil water contents were somewhat overestimated, and solute concentrations were underestimated. Differences between predicted solute distributions obtained with the CDE and MIM transport models were relatively small. This and the value of optimized parameters indicate that observed data were sufficiently well described using the simpler CDE model, and that immobile water did not play a major role in the transport process.

Manure phosphorus (P) in excess of the assimilative capacity of land available on farms is an environmental concern often associated with confined livestock production. A wastewater treatment process was developed for removal of phosphorus from livestock wastewater. It includes nitrification of wastewater to remove ammonia and carbonate buffers, and increasing the pH of the nitrified wastewater by adding an alkaline earth metal-containing compound to precipitate phosphorus. Since ammonia nitrogen has been mostly converted to nitrate, increased pH does not result in significant gaseous nitrogen loss. The amount of phosphorus removed, and consequently the N:P ratio of the effluent, can be adjusted in this process to match specific crop needs or remediate sprayfields. In addition to the phosphorus removal aspect, the high pH used in the process destroys pathogens in liquid swine manure. The final product is calcium phosphate, which has the potential to be reused as fertilizer or processed to produce phosphate concentrates.

Water extraction studies were carried out on velvet (Mucuna) beans to determine extraction rate of L-dopa as a function of bean particle size, temperature, and pH. Samples from which L-dopa had been successfully extracted were also assayed for total protein content to determine associated protein loss. Extraction with room temperature tap water was feasible only with the smallest particle size studied (1 mm). At this size, a safe level (0.1%) could be reached within approximately 55 h (2.5 days) of soaking in a minimum of 40/1 parts water/bean. Extraction rates increased dramatically with increased water temperature, allowing safe levels to be reached within 13 h at 40 degrees C and 3 h at 66 degrees C, suggesting, only 40 min would be required in boiling water. Extraction rates increased further with decreasing pH at any temperature. Acidifying water at room temperature to pH 3 allowed extraction to safe levels in less than 8 h. However, increasing water pH into the alkaline range appeared to induce chemical conversion of L-dopa to melanin. No significant loss of protein was found in any of the samples assayed. It appeared that optimum conditions for water extraction of L-dopa from Mucuna bean are similar to those required for brewing of coffee. Beans must first be ground to small particle size and then extracted with hot water.