This thesis seeks to identify the potential for the unconstrained minimization algorithms of mathematical programming to be cost-effective with the conventional techniques of nonlinear structural analysis. With this in mind, the author has attempted to critically evaluate a few of the more commonly used algorithms for their effectiveness in solving structural problems involving geometric and/or material nonlinearities. The algorithms have been categorized as being zeroth order requiring only function evaluations, first order requiring evaluation of both the function and the gradient or second order requiring in addition a variable metric. The sensitivity of the first and second order algorithms to the accuracy of derivatives derived on the basis of finite difference operations clearly suggests using analytically derived derivatives in order to obtain better control of the computational effort required for convergence to the exact solution. The thesis concludes by attempting to identify the algorithm which promises to be most effective in predicting nonlinear structural response and suggests improvements that could be made to make it even more cost-effective when compared with other well known techniques of nonlinear structural analysis. / Master of Science

<u>Taphrocerus schaefferi</u> is a leaf miner of yellow nutsedge, a serious weed of many agronomic and horticultural crops. Beetles begin egg-laying in early June; the eggs have an incubation period of 16 days. There are three larval instars, the first two of which consume only the chlorenchyma and upper epidermal cells of the infested leaf. The third instar is responsible for most of the tissue destruction. Approximately one half of the vascular bundles are destroyed. Larvae are cannibalistic and only one larva per leaf can develop. The larval and pupal stadia are 20 and 11 days, respectively. Adults emerge in late July and August. The immature stages are described and illustrated. The life cycle of <u>T. schaefferi</u> is well synchronized with that of its host. The primary mortality factor of the immature stages is two larval and pupal chalcid parasites which account for 74% of the total larval mortality. The total dry weight of plants without leaf miners is significantly greater at the P< 0.05 level than those plants with 5-8 leaf miners present. However, the development of <u>T. schaefferi</u> causes only minimal damage to the host. Mining occurs only in mature leaves, the first and second instar mine is superficial, and the third instar mine occurs near the onset of leaf senescence. As a consequence, the biocontrol potential of <u>T. schaefferi</u> is limited. A survey to detect the presence of <u>Elliponeura debilis</u> Loew (Diptera), a seed feeding chloropid, and <u>Glyphipteryx impigritella</u> Clemens (Lepidoptera, Glyphipterygidae), a leaf miner, was conducted. / Master of Science

This study was designed to identify factors influencing relocation to retirement communities. Participants were residents of two New Jersey retirement communities which offered single family detached dwelling units with common grounds, community recreational facilities, and security guards. Residents paid monthly maintenance fees to cover operation of the common areas. Total sample size was residents of 160 dwelling units. Specifically, respondents were from 40 units, or a 40 percent sample, in an Ocean County community and from 120 units, or a 10 percent sample, in a Burlington County community. The researcher developed a test instrument designed to ascertain reasons for relocation. Data were collected October 11-17, 1976, by the researcher who contacted the subjects at their homes. First, it was found that no significant differences existed between the samples and that only three items relating to influences upon mobility were significantly different between communities. These items were the large size of one's last dwelling unit, high property taxes on the last dwelling unit, and the value of one's new dwelling unit for the money. Second, no one factor precipitated relocation; rather, it was a combination of factors within the old and new near environments. Last, dwelling unit and neighborhood factors for the old and new near environments were influences, but community factors were only an influence as they relate to the new near environment. / Master of Science

A procedure is developed to examine the parameters affecting the accuracy of the vortex-lattice method when applied to a nonlinear lifting surface problem with leading edge separation. Among the factors investigated are the extensions of the bound vortex segments off the sharp edges of the wing, modifications of the Biot-Savart law to damp out near singularities, the length of the free vortex segments, the placement of the control points on the surface of the wing, and methods of applying the no-penetration boundary condition and spatial conservation of circulation. Two methods of force and pressure calculations are considered and an interpolation procedure is introduced to represent the pressure distribution as a continuous function over the surface of the wing. Delta, arrowhead, and cropped delta wings are presented as numerical examples. Parametric studies are made for the delta wing of aspect ratio one. It is found that the parameter which has the greatest influence on the solution is the extension of the bound vortex segments adjoining the leading edge off the leading edge. / Master of Science

Five states were chosen for the study: New York, Massachusetts, California, Oregon and Washington. The author visited each of the five states and Washington, D.C. in 1976 to collect writings, published and informal, and to interview persons concerning the historical background and implementation of the states' forest practice acts. The changing national attitudes toward the use and abuse of forest resources was traced as historical background. For each state, the political forces involved with forests were examined to determine how they contributed to the development and current form of the forest practice act. The purposes for which the states' acts were passed were analyzed. Available information on costs and benefits were included to illustrate what a state might expect if it decides such a program is desirable. Criteria were developed for evaluating the success of a state's forest practice act. A list of apparently successful features of selected administrative and regulatory systems was included to illustrate what form a model forest practice act might take. The criteria for success that were developed are: (1) improvement in existing conditions; (2) financial impacts on the timber operator, forest landowner and the state; and (3) the administrative development of regulations. Successful administrative and enforcement systems were: (1) part-time, independent forest practice boards promulgating regulations based on legislative policy; (2) single agency enforcement; (3) classification of forest practices according to their potential for environmental damage; and (4) a priority inspection system. / Master of Science

A numerical analysis of the nonlinear response of bonded joints is presented. Mechanical and thermal loadings are considered. Material stress-strain response is represented by Ramberg-Osgood approximations. Temperature-dependent properties including modulus percent retentions and coefficients of expansion are modeled with linearly segmented curves. Bonded joints with graphite-polyimide, boron-epoxy, titanium, or aluminum adherends are analyzed using a quasi 3-dimensional finite element analysis. In adhesively bonded joints, the adhesives considered are Metlbond 1113 and AF-126-2. Elastic results are presented for single and double lap joints, with and without adhesives. It is shown that mechanically induced stresses are greatly affected by longitudinal adherend stiffness. The effects of adherend transverse stiffness are shown to be significant in some cases. Residual curing stresses are shown to be significant in all joints except those with similar adherends and no adhesive. Nonlinear results are presented for adhesively bonded joints. It is shown that adhesive nonlinearities are only significant in the predicted adhesive shear stresses. Adherend nonlinearities and temperature-dependent properties are shown to have little effect upon the adhesive stress predictions under mechanical and thermal loadings. / Master of Science

An investigation of rotor blade pressure distributions at three-span positions during surge of a low-speed axial-flow compressor was conducted for a single throttle position. The operating path of the compressor system was experimentally determined and the blade pressure distributions were correlated to their point of occurrence during the surge cycle. A comparison of these pressure distributions with the blade pressure distributions obtained during steady-state operation of the compressor at the same throttle position is presented. The steady-state compressor characteristic was determined to show the range of operation of which the compressor was capable. A mathematical model was applied to the experimentally-determined compressor characteristic and the system geometry varied to determine its effect on the stability. The effect of the time response of the compressor, to changes in mass flow rate, on the stability of the system was also investigated. / Master of Science

The purpose of this exploratory study was to investigate the factors associated with the selection of riding attire worn by horse show exhibitors. The second purpose was to compare this data to similar data obtained from professional judges. Two instruments were developed to provide data to meet objectives and hypotheses. Data was collected from 127 horse show exhibitors from the mailing list of the Appalachian Horse Show Association, and also from 24 judges of the American Horse Show Association. Statistical analysis included condescriptive information, one way analysis of variance, frequency distribution, Chi-square, t-tests, and z-tests to investigate relationships between variables for significance. The most important appearance factor in selection of riding apparel on the part of both exhibitors and professionals was that apparel be appropriate for the class entered. Exhibitors felt that apparel plays more than average importance in a judge's evaluation. Professionals placed average importance on apparel in their evaluation. Professionals were most frequently consulted by exhibitors about colors and styles to select. Professionals indicated they most frequently gave advice on rules governing dress, then on styles and colors to select. The most difficult problem for exhibitors in locating desired apparel items was the distance to an appropriate store. There was a significant difference between horse's breed and the desire for the color of the habit to be compatible with the exhibitors' horse. There was no significant difference for the following variables: amount of competition by breed, appearance factors with source of income or education, amount of competition with source of income or education. Professionals' and exhibitors' opinions governing riding apparel did show some significant relationships.: / Master of Science

The purpose of this study was to ascertain if day care significantly alters the child's propensity toward the formation and maintenance of attachment bonds towards its mother. It was maintained that the variable of day care in the life of an infant would cause disruption to his attachment to his mother sufficient to elicit attachment behaviors different than those of his counterpart home reared infant when they were placed in a strage environment. This assertion was based on the ethological-evolutionists theory which maintains that the rearing environment cannot alter significantly from that environment of evolutionary adaptiveness if a secure mother-child attachment is to be formed. The observation checklist, designed by Morgan and Ricciuti was employed to measure the reactions of eight day care and eight home reared infants, ten to eighteen months, to an adult male and an adult female stranger. The checklist was composed of two behavioral scales - facial expression and motor activity - to rate the infant's reactions to the strangers. A movie camera was used to record the testing to insure the reliability of the observations. No significant difference occurred between the day care infants' responses and the home reared infants' responses. Daily separation for these day care infants, therefore, was not a sufficient enough disruption in the attachment process to cause the exhibiting of different attachment behaviors than their counterpart home reared infants. / Master of Science

Channeled streams tended to have higher drift densities and lower benthic standing crop densities than unchanneled streams. Drift densities increased markedly below a small flood control impoundment as the result of the influx of large numbers of organisms of limnetic origin. The density of these organisms in the drift decreased rapidly as the distance downstream from the reservoir increased. / Master of Science