The purposes of this study were to develop a reliable bench-scale testing procedure to adequately predict polymer conditioning requirements for full-scale belt filter presses, and to determine the additional polymer demand exerted by applied pressure during the expression stage of a dewatering process. Bench-scale experiments performed with anaerobically digested, alum, and secondary sludges used a high-speed mixer to gauge mixing intensity effects, and a wedge zone tester to gauge applied pressure effects on conditioning requirements. Full-scale experiments varied Sludge throughput, belt speed, and polymer dose to evaluate polymer performance. The polymer requirements to optimize performance of a full-scale belt filter press can be predicted with a bench-scale mixing device, where the shear (Gt) of the mixer matches that of the full-scale press. An estimate of the Gt value of the full-scale belt filter presses used in this study was 10,000. Alternatively, a bench-scale wedge zone tester, operated in an applied pressure range between 5 psi and 20 psi, can predict polymer doses for optimum belt filter press performance. The range of applied pressures used to simulate the expression phase of a dewatering process did not exert a Significant additional polymer demand for optimum conditioning. The shear (Gt) associated with mixing sludge and polymer during conditioning can exert a greater polymer demand than the expression phase of the wedge zone tester. / Master of Science

The probability of mortality for an individual tree with certain characteristics growing under certain conditions was modeled. A particular algorithm SCREEN was used to fmd the best set of predictors variables. This algorithm was specially created to be used when the dependent variable can take only two values like in this binary case (dead or alive tree). The logistic model with different independent variables, which were found to be significant through the SCREEN algorithm, was fitted to the data. For the unthinned plots the logistic model with the following variables, CR (crown ratio), HH (total height/height of dominant and co-dominant trees) and CI (competition index) was compared with the survival model applied in a published distance-dependent model PTAEDA. The logistic model with CR, HH and DD (quadratic mean diameter/dbh) was compared with the survival model already used in a distance-independent model TRULOB. In both cases the behavior of the logistic model was quite similar to the published models. For the thinned plots the predictor variables DDt HH, CI and CR raised to 1.5 were used in the logistic model to predict mortality for individual trees. Mortality is difficult to predict. In this particular study the logistic model was used. The final distance-dependent model for unthinned plots includes as predictor variables CR, HH and CI. For thinned plots the final logistic model employs HH, CI and CR raised to 1.5 as independent variables. The final distance-independent model for unthinned plots includes as predictor variables HH, DD and CR. For thinned plots the final logistic model uses HH, DD and CR raised to 1.5 as independent variables. Differences between deterministic and the stochastic treatments of mortality were also studied. No practical differences in several stand characteristics such as average height, total volume, basal area were found when using these two approaches. Further, no significant differences were found in the diameter distribution for dead or alive trees. / Master of Science

A method for multivariate quality control with the dual objectives of providing a true level of sampling error probabilities for the joint control of several quality variables while also giving problem diagnoses for the quality variables individually. The method is comprised of an afine transformation of the multiple quality variables which creates a univariate test statistic used to monitor the quality and provide problem diagnoses. In practice, realized values of this statistic would be plotted as a time series on a control chart with multiple diagnosis intervals. For the analysis of the method’s effectiveness, the quality variables are assumed to be independent and normally distributed. The method is shown to be successful in achieving desired sampling error probabilities for any m quality variables in the case of positive shifts in the means of the variables. A second transformed variable is added for the diagnosis of shifts of unrestricted direction, and its effectiveness is analyzed. The sample size requirement of the afine transformation method is compared to the total sample size necessary when a separate Shewhart chart for the mean is maintained for each quality variable with the same overall sampling plan objectives. The power of the method to detect quality problems in general while disregarding specific diagnoses is compared to the power of Hotelling’s T² test for multivariate quality control. A comprehensive evaluation of the relative worth of the two methods is not possible since the T² statistic does not consider diagnoses of the individual quality variables. / Master of Science

This thesis develops a framework to guide the incremental design and implementation of a Computer-Integrated Manufacturing System (CIMS). The framework is premised upon the facts that: (1) CIMS design is accomplished through a series of evaluation decisions sequenced through time and (2) evaluation is accomplished by decomposing the entire manufacturing organization into its essential activities and transactions. The effects of computerization on these activities and transactions are determined and these effects are then related to impacts on a set of selected evaluation criteria. Formal methods for benefit quantification are not included. The user of this framework is required to: (1) specify a set of relevant evaluation criteria, (2) define essential activities and transactions of their organization, and (3) derive organization-specific affect/impact relationships. The framework structures these activities for the user and suggests a series of matrices that can be used to guide the user through the steps of the framework. Use of the framework is demonstrated as various aspects of an implementation decision currently being faced by a manufacturing organization are analyzed. The implementation decision concerns whether to implement a computerized production planning and scheduling system and aspects of the decision which are considered include impacts on organizational flexibility, responsiveness, and skills. The required changes in authority relationships and the assignment of task responsibilities are also considered. Using results from this case study, the usefulness and appropriateness of the framework was assessed. Although there was no quantitative measure available, the client deemed the framework useful for analyzing and guiding their implementation decision. Suggested improvements to the framework are presented. / Master of Science

Monolithic ceramic materials have been used in industry for hundreds of years. These materials have proven their usefulness in many applications, yet, their potential for critical structural applications is limited. The existence of an imperfection in a monolithic ceramic on the order of several microns in size may be critical, resulting in catastrophic failure. To overcome this extreme sensitivity to sman material imperfections, reinforced ceramic materials have been developed. A ceramic matrix which has been reinforced with continuous fibers is not only less sensitive to microscopic flaws, but is also able to sustain significant damage without suffering catastrophic failure. A borosilicate glass reinforced with several layers of plain weave silicon carbide cloth (Nicalon) has been studied. The mechanical testing which was performed included both flexural and tensile loading configurations. This testing was done not only to determine the material properties, but also to initiate a controlled amount of damage within each specimen. Several nondestructive testing techniques, including acousto-ultrasonics (AU), were performed on the specimens periodically during testing. The AU signals were monitored through the use of an IBM compatible personal computer with a high speed data acquisition board. Software has been written which manipulates the AU signals in both the time and frequency domains, resulting in quantitative measures of the mechanical response of the material. This paper will compare the measured AU parameters to both the mechanical test results and data from other nondestructive methods including ultrasonic C-scans and penetrant enhanced X-ray radiography. / Master of Science

Amino polyaromatic hydrocarbons (amino PAHs) and nitro polyaromatic hydrocarbons (nitro PAHs), two highly mutagenic classes of compounds, are proposed to be metabolized to an electrophilic aryl nitrenium ion which attacks DNA and forms DNA adducts. A structure-activity relationship was investigated between aryl nitrenium ion stability and mutagenic activity. Arylnitrenium stability for seventeen amino PAHs was measured using electron ionization mass spectrometry. The ratio of [M-1]⁺/M⁺ intensities was used as an indicator of nitrenium ion stability. These values were then compared to mutagenicity data from the Ames Salmonella assay. Physical descriptors of isomer classification (based on ring size and shape) and isomer position of substitution were used in the statistical analysis. A strong correlation between mutagenicity, isomer classification, and stability was found (r²= 0.899 and p<0.001). This finding agrees with reported literature that the compound's physical features of ring size and position of substitution affect mutagenicity. A high correlation of r² = 0.955 was found between mutagenicity, isomer classification, and stability for three sets of isomers: 1- and 2-aminoanthracene, 1- and 2-aminonaphthalene, and 1- and 2-aminofluorene. The nitrenium ion formed from the 2 position was found to be less stable and more mutagenic than the 1 position. This finding agrees with correlations found between mutagenicity and LUMO (Lowest Unoccupied Molecular Orbital) calculations of the electrophilicity of the nitrenium ion. These results indicate that the less stable the nitrenium ion within an isomer pair, the more mutagenic the amino PAH. / Master of Science

The active magnetic bearing (AMB) is a relatively new technology which has many advantages compared with conventional bearing design. In an AMB system, the rolling-element back-up bearings are indispensable to protect the magnetic bearing rotor and stator, and other stationary seals along the rotor shaft. In this paper, a theoretical formulation is proposed and solved numerically to examine the transient response of the flexible rotor, from the time just previous to the AMB shuts down and including the rotor drop onto the back-up bearing. The backward whirl of the rotor, which may lead to the destructive damage of the machinery, has been analytically predicted at very light support damping and very high support damping. Also, the vibration due to the non-linearity of the contact point geometry has been included in the analysis. The influence of the support damping on the displacement of the disk and also the contact force between the journal and the inner-race of the back-up bearing have been computed for various rotor system parameters. By comparing these results with the optimum support damping for the simple flexible rotor model, it is shown that this support damping optimization can be applicable for specifying the required optimum range of support damping for the back-up bearings of AMB systems. / Master of Science

The need for better performance of turbomachinery with active magnetic bearings has necessitated a study of such systems for accurate prediction of their vibrational characteristics. This research presents a modification of existing transfer matrix methods for rotor analysis, to predict the response of rotor systems with active magnetic bearings. The position of the magnetic bearing sensors is taken into account and the effect of changing sensor position on the vibrational characteristics of rotor systems is studied. The modified algorithm is validated using a simpler modified Jeffcott model. The effect of changing from a rotating unbalance excitation to a constant excitation in a single plane is also studied. An eight-stage centrifugal compressor rotor is analyzed using the modified transfer matrix code. The results for a two-mass Jeffcott model are presented as plots of critical frequency vs. sensor position and amplitude at critical frequency vs. sensor position. Plots of amplitude vs. frequency and phase angle vs. frequency for different cases of sensor location are also presented. The results obtained by analyzing this two-mass model with the modified transfer matrix method have been compared with the results of the modified Jeffcott analysis for the purpose of verification. Also included are plots of amplitude vs. frequency and phase angle vs. frequency for the eight-stage centrifugal compressor rotor. These plots will demonstrate the significant influence that sensor location has on the critical frequencies and the amplitudes at the critical frequencies of the rotor system. / Master of Science

Rudbeckia hirta I Marmalade' plants at different leaf numbers were exposed to a (long day) LD photo period in order to quantify the end of juvenility. A quadratic relationship existed between flowering and both the number of leaves the plant possessed and the number of days from onset of LD. The loss of juvenility occurred in the shortest time, 42 days, plants had 15-24 true expanded leaves. The greatest stem height also corresponded to this same leaf number. The number of LD received did not affect ray floret number per inflorescence, scape length and capitulum diameter excluding ray florets. Gaillardia pulchella flowered most rapidly in 49 days, with a minimum of 14-20 expanded leaves as described in a quadratic relationship. Histological studies during evocation indicated an increase in apical meristem widths (120 pm to 224 pm) and heights (21 ~m to 48 pm), an increase of 2 to 5 tunica cell layers, greater corpus organization, and a lower point of primordia attachment with respect to increased doming of the apex all occurring with maturity of the apex. Solidago flexicaulis exhibited a complex (combination) photoperiodic response, requiring an extended LO exposure prior to SO initiation. The last treatment, consisting of 12-week-old-plants transferred from LO to SO, flowered most rapidly in 62 days. Other measured characteristics such as stem length, dry weight of all tissue above and below the soil line, number of basal shoots and main axis leaf number were not different depending on amount of SO induction. There was a difference in the above measured variables, except emerged basal shoots and leaves per main axis, between control LO plants and all averaged SO treated plants. / Master of Science

Earlier studies have demonstrated that nitrosoureas such as 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) and chlorozotocin (CLZ) can cure almost 100% of C57BL/6 mice bearing syngeneic LSA tumor. In contrast, similiar or higher doses of streptozotocin (STZ) completely failed to cure LSA-bearing mice. Further studies revealed that the efficacy of nitrosoureas may depend on their immunomodulating properties. In the current study, therefore, attempts were made to investigate the effects of these nitrosoureas on the immune system of normal and LSA tumor-bearing mice. Treatment of normal C57BL/6 mice with 5 intraperitoneal injections of 20 mg/kg body weight of BCNU or CLZ caused an increase in the percentage of CD4⁻ CD8⁻ T cells and a decrease in the percentage of CD4⁺CD8⁺ T cells in the thymus. In addition, such treatment also caused an increase in the percentage of CD4⁺ T cells without significantly affecting the CD8⁺ T cells in the thymus. However, when total cellularity of the thymus was studied, BCNU and CLZ were found to decrease the total number of CD4⁺CD8⁺ T cells without significantly affecting the other subsets. In contrast, similiar or higher (100mg/kg body weight) doses of STZ had no significant effect on the total number and percentages of T ceil subsets in the thymus. Also, BCNU and CLZ but not STZ-treatment caused a 50% decrease in the total number of CD4⁺ and CD8⁺ T cells in the spleen. Interestingly in tumor-bearing mice, BCNU treatment was followed by a ten-fold increase in the percentage of CD4⁺ T cells found in the peritoneal cavity. The percentages of CD8⁺ cells increased also, but to a lesser degree. These changes were limited to the peritoneal cavity which is the site of tumor growth. When T cells in the spleens of nitrosourea-treated normal mice were functionally analyzed, it was observed that BCNU and CLZ caused a dramatic decrease in the T cell responsiveness to Con A, anti-CD3, and PMA + calcium ionophore stimulation. In contrast, STZ treatment failed to significantly inhibit the T cell responsiveness to these activation signals. Using the accessory cell-dependent and independent assays, BCNU and CLZ were found to suppress the functions of both T cells and macrophages in normal mice. BCNU and CLZ also suppressed the B cell responsiveness to lipopolysaccharide (LPS). Also, addition of growth factors such as IL-1, IL-2, IL-4 and IL-6 failed to reconstitute the defective responsiveness of BCNU and CLZ-treated T cells and macrophages. Together these data suggest that nitrosoureas have varying immunomodulating properties and this may in turn determine their efficacy in the treatment of cancer. / Master of Science