Advances in nanotechnology have enabled the production and characterization of magnetic particles with nanometer-sized features that can be functionalized with biological recognition elements for clinical and biosensing applications. In the present study the synthesis and interactions between self assembled monolayers (SAMs) and functionalized nanoparticles have been characterized. Size and shape of magnetic nanoparticles synthesized wet chemically starting from ferrous and ferric salts were verified by transmission electron microscopy (TEM). These nanoparticles were then conjugated with FITC-labeled streptavidin through carbodiimide (EDC) chemistry. SAMs of thiol-capped biotins were synthesized on gold surfaces for capture of the conjugated nanoparticles. Characterization of nanoparticle functionalization and binding was performed using fluorescent microscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS). FT-IR spectra confirm the binding of biotin on gold via sulphur linkages. Fluorescent microscopy and XPS show streptavidin bound to the biotinylated gold surfaces. Elemental characterization from EDS indicates the binding of streptavidin-conjugated nanoparticles to biotinylated gold surfaces. Together, these techniques have application in studying the modification and behavior of functionalized nanoparticles for biological and other applications.

The goal of the research was to synthesize magnetic polymeric nanoparticles (MPNPs) under 100 nm in diameter, for future drug delivery applications. The thesis is divided into two main sections. In the first section, a quantitative, and comprehensive description of the top-down synthesis techniques available for poly(lactide-co-glycolide) (PLGA) and magnetic polymeric nanoparticles (MPNPs) formation is provided, as well as the techniques commonly used for nanoparticle characterization. In the second part, a novel way to form MPNPs is presented. The emulsion evaporation method was selected as the method of choice to form poly(lactide-co-glycolide) (PLGA) nanoparticles with entrapped magnetite (Fe₃O₄) in the polymeric matrix, in the presence of sodium dodecyl sulfate (SDS) as a surfactant. The magnetite, a water soluble compound, was surface functionalized with oleic acid to ensure its efficient entrapment in the PLGA matrix. The inclusion of magnetite with oleic acid (MOA) into the PLGA nanoparticles was accomplished in the organic phase. Synthesis was followed by dialysis, performed to eliminate the excess SDS, and lyophilization. The nanoparticles obtained ranged in size between 38.6 nm and 67.1 nm for naked PLGA nanoparticles, and from 78.8 to 115.1 nm for MOA entrapped PLGA nanoparticles. The entrapment efficiency ranged from 57.36% to 91.9%. The SDS remaining in the nanoparticles varied from 51.02% to 88.77%.

Robotics is a rapidly growing technology and robots have pervaded into most of the industries. Robotics and automation are designed to remove the human factor from the labor intensive and monotonous work and thereby decrease the associated costs. The application of robotics to agriculture is fairly recent. Robotic applications in agriculture vary from autonomous row-guidance tractors to fruit picking robots. Similarly, soil testing and soil sampling is one area in agriculture where automation of tasks and the employment of an autonomous robot would be of great use to consultants and farmers employing site specific farming techniques. Soil testing is an important part of farming used to determine the average nutrient status in a field and to obtain a measure of nutrient availability in the field. Fertilizers and other nutrients are applied to the fields based on different soil tests. Site specific farming is greatly dependent on soil testing and can result in increased yield, reduced cost and reduced water pollution. Soil testing requires a lot of soil samples and soil sampling is a time consuming, laborious process and expensive process. Most of the consultants employing site specific techniques use ATVs to get around large fields when sampling. The development of an autonomous guidance system for an ATV to perform soil sampling would be greatly beneficial to them. Labor costs would be significantly reduced and the operators would be subjected to fewer environmental elements. The use of ATVs ensures that no extra capital is needed to buy a vehicle. The use of a small vehicle like an ATV also causes less soil compaction. A WAAS enabled Differential GPS with accuracies to within 9.84 feet was used as the position sensor. Pocket PCs are more portable than a laptop computer and are more suitable for farm conditions. Shape files were used to provide the sampling points as input to the guidance program. A guidance program was made to operate on a PDA and provide guidance instructions. A microprocessor was programmed to read the guidance instructions and actuate the different components like throttle and steering. Tests were conducted to test the accuracy and consistency of the system. The offsets of each stop point from the test point were documented and analyzed. The results indicated that the system was as accurate as the GPS used for guidance. They also indicated that a guidance system can be realized with the use of very few components and an accuracy needed for soil sampling can be achieved. Avoidance routines for obstacles within the field were indicated as future developments.

Remote sensing has been used in precision agriculture for monitoring crop health, weed management, detecting nutrient stress, and yield forecasting. One method of implementing remote sensing is through aerial imagery. Aerial imagery is being used in precision agriculture for a variety causes such as to detect crop stress, fertilizer skips and overlaps, nitrogen excesses and deficiencies and detect irregular or reduced crop stand. These crop features are noted by extracting spectral information from the images. The spectral data is obtained from the images by using software programs. The software programs process the images one at a time or assemble them together and process them all at once. To obtain information about an extensive region of agricultural crop and save time, it is advisable to assemble the images and process them simultaneously. This research provides a low cost software program to assemble images and process the images simultaneously to obtain data pertinent to make decision process regarding agricultural crops. This study utilized geographic location of the area being photographed as reference points for creating the mosaic of the images taken. The software has the ability to assemble images taken randomly over a specified area. Vegetative indices are used as the parameter to detect crop vigor and density. Normalized difference vegetative index and ratio vegetative index were measured from the spectral information in the images. The software achieved the capability of assembling 100 randomly taken images in less than two minutes and represents the variation in vegetative indices in varying shades of red, providing a map for detecting crop variability.

Escherichia coli O157:H7 contamination is a major hazard in the water supply, causing outbreaks of disease. Conventional methods of E. coli O157:H7 detection usually takes 1-2 days and require hands-on preparation. There is a need to develop a rapid, inexpensive means of detecting the organism. The amperometric biosensor technology has achieved success in the area of metabolite detection. In this study, a bench scale amperometric biosensor was investigated to rapidly detect Escherichia coli O157:H7. The amperometric biosensor consisted of a power source, Clark electrode, autoranging picoammeter, and fabricated polyvinyl chloride (PVC) outer insert with nitrocellulose membrane and attached horseradish peroxidase labeled E. coli antibodies. The interaction of horseradish peroxidase and hydrogen peroxide produced dissolved oxygen which is thought to be altered by the binding of the antigen to the antibody. After submerging the amperometric biosensor in the samples containing various concentrations of heat sterilized E. coli O157:H7 cells, as little as 10 cells/ml of E. coli O157:H7 were detected. The time for detection for the final system was approximately 20 minutes. There was a need to use a custom conjugated antibody to control and increase the molar concentration of conjugated HRP. The minimum concentration of HRP needed for this system was 6 X 10-8M HRP. The system showed optimal performance at pH values 6-8 and showed no response in acidic environments with pH values less than 5. The sensor also showed good performance between 10-30°C. The results indicated that change in dissolved oxygen response was able to distinguish between 0 and 10-5000 cells/ml by maximum increases in dissolved oxygen of 3.53mg/L ± 0.26mg/L when bacterial cells were present and increases in the order of 6.26 ± 0.64mg/L when no cells were present. Despite satisfactory performance as an indicator method, the amperometric biosensor failed to quantify the organism. Further optimization experiments of the amperometric biosensor may be necessary for quantification. The amperometric biosensor with the use of a sandwich assay evaluated in this study offered a reliable means of quantification of the organism. Overall, the amperometric biosensor technology offered an efficient means of detection because of its ease of use and inexpensive, portable instrumentation.

The oysterbreak is a method of growing an oyster reef into a wave attenuating device. A study was conducted to determine an optimal material for the oysterbreak. As oysters grow on the oysterbreak, wave energy in the lee of the structure is reduced. It was predicted that more rapid oyster growth would lead to a more rapid reduction of wave energy. Louisiana is losing coastal marshes at an alarming rate. Wave action from storms erodes sediments from Louisiana's shorelines and barrier islands. Structures such as the oysterbreak may be used to protect Louisiana’s fragile shorelines. A material for the oysterbreak may also be used to produce artificial oyster reefs or harvestable oyster cultch. Concrete makes an excellent structural material and is attractive to oysters. It was hypothesized that adding cottonseed or crushed oyster shell to concrete would stimulate greater oyster growth than on concrete alone. The objectives of this study were to 1) determine whether concrete containing either cottonseed or oyster shell would have a greater increase in cross section due to oyster growth compared to concrete with no biological additive and 2) determine the structural properties of concrete with increasing amounts of cottonseed. Concrete samples were deployed in Caminada Bay near Grand Isle Louisiana in June of 2005. By March of 2006, concrete with oyster shell experienced the most growth (16.2% increase in perimeter of the bar), followed by samples with cottonseed (11.2% increase in perimeter). Samples with no additive had the least oyster growth (7.9% increase in perimeter). An experiment was also conducted to determine the structural properties of concrete with cottonseed in it. Density ranged from 2.25 g/cc for samples with no cottonseed to 2.05 g/cm3 with samples with a high concentration of cottonseed. Strength ranged from 27 MPa for samples with no cottonseed to 7 MPa for samples with the highest concentration of cottonseed. It was determined that this range of strength was acceptable for use in the oysterbreak. It was also concluded that concrete containing either cottonseed or oyster shell would make a superior material for the oysterbreak, compared to concrete alone.

The ultimate goal of this research is to characterize data from the laboratory, pilot, and industrial scale rice mills. Pilot and laboratory scale data are presented in this research. Two long grain rice cultivars were milled with two different scale mills. Cheniere and Cypress were milled with a McGill No. 2 mill and a pilot scale mill (Satake). Both material streams, rice kernels and bran, were collected and weighed. Measurements of Degree of milling, transparency, and whiteness were made with a milling meter (Satake). Yield and bran fraction were calculated. Samples of the bran were heat stabilized and prepared for high pressure liquid chromatography (HPLC). HPLC analysis determined the concentration of vitamin E and oryzanol. Parameter values were reported as laboratory, pilot, or category assignment of low, medium, and high. Yield values for both rice varieties and both mill scales were highest at the low category. Degree of milling measurements increased with increasing process time setting for the laboratory scale mill and with increasing operational mill setting for the pilot scale mill. DOM data divided by category showed an increase for both varieties and both mill scales from the low to high categories. Transparency and whiteness values increased from low to high category. At the laboratory scale mill, for Cheniere, the highest levels of vitamin E and oryzanol occurred at the 10 second mill setting. For Cypress, the highest level of vitamin E occurred at the 10 second mill setting, and the highest level of oryzanol resulted at the 5 second time setting. Category and pilot scale values for both vitamin E and oryzanol were highest at the low category or the lowest mill setting.

The purpose of this study was two-fold, 1) to extract and quantify vitamin E components from rice bran using microwave extraction, to determine the antioxidant activity of the rice bran oil, and the effect of solvent and temperature on vitamin E components and oil yield, and 2) to entrap alpha-tocopherol into polymeric nanoparticles, to characterize the nanoparticles in terms of morphology, size and size distribution, zeta potential, entrapment efficiency, and amount of residual PVA associated with the nanoparticles, as well as to study the release of alpha-tocopherol from PLGA nanoparticles. Microwave-assisted extraction was an efficient method for the extraction of oil and vitamin E components from rice bran. Hexane was a better solvent for rice bran oil extraction as compared to isopropanol at 40ºC. At higher temperature, isopropanol was a better solvent for oil extraction. Hexane extracted large amount of α-tocotrienol at 120ºC while the increase in temperature for isopropanol was more beneficial for the extraction of γ-tocopherol. No significant differences in the oil yield, total vitamin E, and antioxidant activity of rice bran oil was noticed between the conventional solvent and microwave-assisted extractions, at 40ºC. For the second part of the study, emulsion evaporation method was used to synthesize spherical PLGA(αT) nanoparticles with SDS and PVA as surfactants. For SDS nanoparticles, the size of the nanoparticles decreased significantly with the entrapment of α-tocopherol in the PLGA matrix, while the size of PVA nanoparticles remained unchanged. The PDI after synthesis was under 0.100 for PVA nanoparticles and around 0.150 for SDS nanoparticles. Zeta potential was negative for all PVA nanoparticles. The entrapment efficiency of α-tocopherol in the polymeric matrix was approximately 89% and 95% for nanoparticles with 8% and 16% α-tocopherol theoretical loading. The residual PVA associated to the nanoparticles after purification was approximately 6% (w/w relative to the nanoparticles). The release profile showed an initial burst followed by a slower release of the α-tocopherol entrapped inside the PLGA matrix. The release for nanoparticles with 8% α-tocopherol theoretical loading (86% released/first hour) was faster than the release for the nanoparticles with 16% α-tocopherol theoretical loading (34% released/first hour).

The erosion control industry uses different types of geosynthetics in order to mitigate the negative impact that erosion has on the environment. One of the most rapidly growing segments within this industry is the natural mats and blankets market. With new environmental regulations and enforcement, the demand for these natural products has considerably increased because of their biodegradability, good moisture retention, low cost and environmentally friendly image. The goal of this present work was to develop a continuous manufacturing process for sugarcane bagasse mats, which could be implemented in the local sugar mills and could provide an economic benefit to both sugarcane industry and road construction industry. To provide the market with a good and competitive product, several designs were tested at Audubon Sugar Institute, St. Gabriel, Louisiana. Using a simple prototype device 1.2 m x 2.4 m sugarcane bagasse mats were produced. Different chemical and mechanical treatments were applied to determine which one will yield the most appropriate bagasse fibers for mat formation. Thermo-gravimetrical analysis was used to compare the effect on bagasse fibers of two chemical treatments: sodium carbonate and sodium hydroxide. Two experimental plots were tested to examine the grass penetration capability of the bagasse mats. The bagasse mats were tested for thickness, weight, strength, water absorption and smolder resistance according to the American Society for Testing and Materials (ASTM) methods, and following the guidelines of the Erosion Control Technology Council (ECTC)

In the state of Louisiana surface irrigation is widely used due to the low start-up cost, typically high rainfall, and soil conditions. Irrigation scheduling is an important practice to achieve water use efficiency in agriculture. The objectives of this study were to compare three different methods to determine crop evapotranspiration (ETc) for soybeans in addition to, evaluate a computer based irrigation scheduling program using real scale fields. Weather variables, soil moisture and irrigation water use collected during the summer months of 2005 and 2006 at a production agriculture farm in northeast Louisiana were studied. The ETc estimates obtained using atmometers (ETgage); a weather station approach; an evapotranspiration algorithm from the computer based Arkansas Irrigation Scheduler (AIS). Three weeks of continuous ETc values showed that the atmometer and the weather station methods estimated similar values. The AIS method estimated lower values than the other two methods. The higher estimates by the weather station compared to the AIS are related to higher ETo values throughout the analyzed period. Similar estimation by the atmometer and the weather station methods suggest that these approaches were more suitable than the AIS method for estimating ETc at Angelina Plantation. The AIS proved to be a good scheduling tool that accurately predicts the crops irrigation needs. However, the results obtained at Angelina Plantation suggest that the farmer or irrigator programs the irrigation events modified by on-farm requirements. The AIS monitored the Maximum Allowable Depletion (MAD). Higher MAD values at the end of the crop cycle reduced the number of irrigations per field but increased the water use. Non-standard procedures implemented in leveled basins suggested a negative impact in the field drainage and made the irrigation process more labor intensive. Extra care is necessary to avoid waterlogging with level basins.