The effects of incorporating pearl millet (<u>Pennisetwn americanum</u> (L.) Leeke) flour into wheat (<u>Triticum aestivum</u> L.) flour along with vital wheat gluten were evaluated. Bread was made from wheat flour (control) and composite flours of 30%, 4O%, and 50% pearl millet Flour replacement with (5%) and without vital wheat gluten. The quality attributes of the loaves were assessed by dough rheology tests, differential scanning calorimetry (DSC), and both objective and sensory evaluation. Farinograph results indicated that millet flour decreased absorption (water uptake) when compared to the control, decreased peak time for dough development and dough stability. Vital wheat gluten increased dough stability of the composite flours. A stepwise decrease in loaf volume was observed with each increase in millet content of the composite flours. Addition of vital wheat gluten did not significantly increase the loaf volume of the breads. Bread made from higher percentages of pearl millet flour also had a higher moisture content, firmer texture and darker crumb color. Differential scanning calorimetry (DSC ) results indicated that the control breads staled faster and that loaves of bread containing 50% millet flour with gluten exhibited the least amount of staling by day 7. Results of sensory evaluation indicated that millet flour replacement resulted in bread with darker crumb and crust color, and a more bitter and intense after taste. Vital wheat gluten was judged by panelists to darken crust color, increase cell uniformity and improve chewiness. Consumer panelists preferred bread made from 30% millet without wheat gluten over the breads made from the other composite flours. In conclusion, pearl millet flour can be used to replace part of wheat flour in the bread making process and the addition of vital wheat gluten is not necessary. / Master of Science

Subsurface bacterial isolates obtained through the DOE Subsurface Science Program were tested for resistance to UV light, gamma radiation and H₂0₂. Some deep subsurface bacteria were resistant to UV light, demonstrating ≥1.0% survival at fluences which resulted in a 0.0001% survival level of E. coli B. The percentage of UV resistant aerobic subsurface bacteria and surface soil bacteria were similar; 30.8% and 25.8% respectively. All of the microaerophilic subsurface isolates were UV sensitive as defined in this work; however, subsurface isolates demonstrated UV resistance levels similar to reference bacterial strains of the same Gram reaction. These results were not in agreement with the hypothesis that the resistance of an organism to UV is correlated with the amount of solar radiation in its natural habitat. Evidence for photoreactivation and the presence of an SOS-like mechanism was also detected in subsurface bacteria. The presence of UV resistance and photoreactivation in subsurface bacteria that have been shielded from solar radiation for millions of years may point to a limited rate of evolution in the deep subsurface environment. In subsurface bacteria, there was a relatedness between UV resistance and resistance to gamma radiation and H₂0₂ UV-resistant aerobic subsurface isolates were also gamma and H₂0₂- resistant compared to the microaerophilic isolates tested. Due to the similarities of bacterial responses to UV, H₂0₂ , and gamma radiation, either UV or H₂0₂ may be utilized to model the effects of ionizing radiation on bacterial cultures used for the bioremediation of organic and radioactive waste-containing environments. / Master of Science

The U.S. Postal Service (USPS) is investing heavily in research and development of automated mail handling systems. A major component in these systems is the use of Optical Character Recognition (OCR) to read the destination address and ZIP Code, and then bar code the mail piece. High speed sorting equipment can then sort the mail using the bar code. Current USPS OCR/automated mail handling systems only process letter mail (no automated address-reading systems exist for nonletter mail). Moreover, these OCR systems only capture and read a restricted field-of-view image. Letters can be rejected by these OCR systems because of nonstandard address location (outside the field-of-view), skewed address lines, or handwritten addresses. Current research is working toward building OCR systems capable of processing all forms of mail which include letters, flats, and irregular parcel and pieces (IPPs). These systems must scan an entire mail image for the destination address block which can assume any orientation. For nonletter mail, such as magazines, this is an exceedingly difficult task, since the entire face of up to 11 by 14 inches must be searched, and the address block must be chosen from all the other extraneous nonaddress information. This paper details an experimental address block location system developed at MITRE. The" system uses a backpropagation neural network trained to discriminate the frequency characteristics of address blocks from other candidates. The current system is trained on magazine flat mail. / Master of Science

Pseudomonas fluorescens, Yersinia enterocolitica, and Listeria monocytogenes readily attach to both rubber and teflon surfaces. Once attached, a glycocalyx covering forms effectively protecting them from any sanitizer that passes over the surface. Therefore, sanitizers efficacy testing done in the laboratory with pure glycocalyx-free cultures could lead to false assumptions as to the sanitizer's true effectiveness under actual use conditions. Our objectives in this study were: (1) evaluate sanitizer efficacy of in use concentrations toward bacteria attached to gasket materials, (2) examine attachment on rubber versus teflon gaskets, (3) examine different methods of enumeration, (4) compare kill of attached bacteria to suspension tests, (5) determine the minimum inhibitory concentrations of Sanitizers. Iodophor, hypochlorite, acid anionic, peroxyacetic acid, fatty acid and QUAT sanitizers failed to provide an adequate log kill of bacteria attached in levels of 10⁴ to 10⁵. Most of the tests showed that the log kill falls well short of a 3 log reduction goal. Plate counts, impedance microbiology, and the direct epifluorescent filter technique were tested as methods of enumeration. Impedance microbiology was the best method of enumeration, since it allows the estimation of both reversibly and irreversibly attached bacteria. Minimum inhibitory concentration tests demonstrated the increased resistance of attached bacteria as compared to cell suspensions. / Master of Science

Although Particle Beam Liquid Chromatography/Mass Spectrometry (PB LC/MS) has been shown to be useful for the identification and confirmation of nonvolatile and thermally labile compounds, evidence has been reported of response nonlinearity at low concentrations. Addition of a mobile phase additive to the HPLC mobile phase improves the linearity via a so-called "carrier effect.” A study has been done to characterize the physical and chemical phenomena involved in this carrier effect. A matrix of probes and additives were combined at 9 levels (2-1000ng) while Single Ion Monitoring (SIM) monitored the effectiveness of each additive on linearity and sensitivity. Next, the pH and concentration of the additive were varied for the 24 sample probes, ranging from pharmaceutical to environmental samples. Data is provided demonstrating the statistical effect on quantitative performance for each study. Analytical examples are shown. A mathematical model has been applied to account for the nonlinearity of PB LC/MS. For a given droplet distribution, reducing the concentration of the analyte results in reduced particle size. Application of a high pass filter to a particle distribution replicates response factor and signal obtained by PB LC/MS. In addition, a mathematical model representing the linear response upon addition of a nonvolatile buffer has been successfully applied. Graphs are presented showing the feasibility of this model. / Master of Science

The focus of this research was primarily on corrosion of the reinforcing steel (rebars) in bridge decks. It has been estimated that over $20 billion is required to repair or rehabilitate corrosion induced deficient bridge decks and that the cost is rising at the rate of $0.5 billion annually. Corrosion occurs when there is a sufficiently high concentration of chloride ions at the top rebar mat. The principal source of chloride ions is from the deicing salts applied on the decks during winter. More than 9 million tons of deicing salts are consumed each year in the U.S.A. As corrosion products have a larger volume than steel, corrosion causes cracking and spalling of the deck. Concrete laboratory specimens with rebars were cast and subjected to a chloride environment. The corrosion potential and rate were monitored with Cu-CuSO₄ half-cell and the 3LP device, respectively. When active corrosion had been initiated, the specimens were treated in six ways, one being the 'control'. Two overlay types and polymer impregnation were used in all combinations as treatment methods. The specimens which were impregnated were grooved and dried to 230 °F prior to impregnation and polymerization. The post-treatment corrosion rates were appreciably reduced. Mortar cubes were made, dried to different temperatures between room temperature and 600 °F, impregnated and polymerized. The cubes were then vacuum saturated and their resistivity obtained. They were then cut, dried to 220 °F and the effects of drying temperature was evaluated using a Mercury Porosimeter and a Scanning Electron Microscope. The cubes were subjected to a chloride environment and subsequent chloride content was determined. The results suggested that a lower drying temperature was sufficient for effective impregnation. Other laboratory specimens were dried to 150 °F and 180 °F and impregnated as before. The post treatment corrosion rates supported the conclusions determined in the cube study. / Master of Science

Today, few water-soluble organometallic compounds are known, and little research has been done in this area. Water-soluble organometallic complexes are of interest for two reactions. First, a water-soluble compound that could be developed as a catalyst eliminates the need for organic solvents and allows the catalyst to be easily recycled. Secondly, water-soluble compounds can be introduced into biological systems, and like the water-soluble complex cisplatin may show anticancer activity. The compound, [lr(COD)(PMe3)3]CI (COD = 1,5-cyclooctadiene, Me = methyl), was synthesized and found to be water-soluble and fairly air-stable. Other water-soluble compounds, [lr(COD)(tripod)]CI, [lr(COD)(dmpe)]CI and [lrH(COD)(PMe3)3]CI2 [tripod = 1 ,1, 1-tris(diphenylphosphinomethyl)ethane, dmpe = (dimethylphosphino)ethane] were also synthesized by similar methods. All of the water-soluble compounds prepared were characterized by nmr and/or x-ray crystallography. [lr(COD)(PMe3)3]CI was found to undergo intramolecular rearrangement in solution and have a square pyramidal structure, which is unique for five-coordinate organometallic compounds. lr(COD) (tripod)]CI was also fluxional in solution, but it had the trigonal bipyramidal structure, usually observed in five-coordinate compounds. Several of the compounds synthesized were submitted to the National Cancer Institute for anticancer screening. Test results showed that the compounds exhibited some anticancer activity, but were non-selective towards a specific type of cancer. Nucleophilic addition reactions between [lr(COD)(PMe3)31CI and several nucleophiles were also studied. / Master of Science

A laboratory investigation was conducted to determine the effects of biologically produced surfactants (biosurfactants) on petroleum hydrocarbons and their potential for the removal of hydrocarbons from groundwater systems. Bioaurfactanta have been found to be produced by microorganisms during growth on insoluble substrates for the purpose of increasing substrate solubility so as to promote biological degradation. In this study, three types of biosurfactants were produced by microorganisms grown on gasoline and a mixture of glucose with vegetable oil. Solubilization and biodegradation of selected gasoline compounds in the presence of bioeurfactante were measured in both static batch and flow through column systems. Batch experiments were conducted in culture tubes, using only liquid phases. A clean sand was used in the column system to monitor physical and chemical interactions yet minimize adsorption effects. A mixed culture of gasoline degrading microorganisms along with isolated cultures grown on selected compounds were used in the biodegradation studies. The biosurfactants produced and used in this study acted similarly to synthetic surfactants and increased, to various degrees, the solubility of the monitored gasoline compounds. Biosurfactants produced from growth on glucose and vegetable oil were very effective surfactants, markedly increasing solubility of the gasoline compounds, but inhibiting biological degradation of these same compounds. Biosurfactants produced by microorganisms from growth on gasoline were effective surfactants, but they did not inhibit biodegradation of the gasoline compounds. This indicated that the biosurfactants may be substrate or microorganism specific, produced for growth on a particular insoluble substrate by a specific microorganism. Biosurfactants produced from growth on gasoline or an insoluble hydrocarbon could therefore be used to enhance solubility and subsequent biodegradation of that same hydrocarbon. The effectiveness of the biosurfactants during application by injection or recirculation for groundwater remediation would be limited by the adsorption and removal of the biosurfactant to the soil. The surfactant demand (by adsorption) of the soil would have to be met before the effects of the biosurfactants would become apparent. Biosurfactanta added to groundwater could also create an additional oxygen demand in a system already low in oxygen. / Master of Science

A strain of Pseudomonas putida that exhibited seedling disease control on cotton was among 5000 strains examined for unique properties that could be used to selectively recover genetically engineered pseudomonads from environmental samples. One isolate (M-17) was found to produce a red halo around single colonies grown on media containing 10 mg/l crystal violet. This decolorization reaction was constitutively produced when the growth medium contained glucose and asparagine, but was inhibited by the substitution of ammonia, nitrate or urea for the amino acid nitrogen source. However, a different medium containing succinic acid and using ammonia as the sole nitrogen source was found to induce the reaction. Factors that did not affect the decolorization reaction included temperature (14-30° C) and pH (3-8). Cultures of M-17 grown in broth containing crystal violet were able to decolorize still broth solutions, but not when incubated on a shaker (150 rpm). Stationary cultures formed a red precipitate. Efforts to characterize the precipitate revealed that it was soluble in polar organic solvents and insoluble in non-polar organic solvents. Thin layer chromatography revealed the presence of six bands that possibly represented various demethylated forms of crystal violet. Chemically derived mutants (cry-) did not produce a red halo but a clear, colorless region surrounding bacterial growth was observed. A greenhouse study demonstrated that strain M-17 provided protection against fungal disease as shown by plant stands on cotton (67% stand) equivalent to the commercial fungicides (70% stand) and significantly improved over the unamended control (38% stand). / Master of Science

Standards for stud strength in composite joists are presently not available. Existing standards for composite design are targeted for composite beam design while design of a composite joist requires more emphasis on stud strength to fully develop the joist bottom chord. Stud placement in the deck flute is investigated. Thirty-six push-off specimens were tested with three different deck geometries. A normal load apparatus models gravity loading in an attempt to represent full-scale joist behavior during the push-off test procedure. The results illustrate that the current AISC specifications (ASD 1989; LRFD 1986) do not accurately predict stud strength for studs placed in ribbed metal deck when the deck is perpendicular to the shear loading. / Master of Science