An approximate method for calculating the steady, incompressible, viscous flow over an airfoil, including regions of separated flow, is presented. The finite-difference equations resulting from an integral method for the laminar and turbulent boundary layers are solved simultaneously in a line-relaxation procedure with the equations for the outer, inviscid flow. These coupled equations allow direct interaction between the viscous and inviscid regions, thus eliminating the mathematical difficulties usually associated with separation. A distributed source on the upper surface of the airfoil provides an outflow to simulate the displaced boundary, and a distributed sink downstream of the trailing edge closes the wake. Computed results, which are compared with measurements for an NACA 4412 airfoil, are quite satisfactory for engineering purposes. / Ph. D.

This dissertation examined the relationship between marketing influence and life satisfaction for elderly consumers. Marketing influence was conceptually explored within the context of a consumer satisfaction/dissatisfaction framework. As such, the construct labeled overall consumer satisfaction was developed and defined as an attitude state representing the specific level of fulfillment of wants or needs possessed by an individual gained from experiential interactions with marketing institutions. This attitude was posited to be made up of a sub-domain structure, with each sub-domain consisting of satisfactions derived from an individual's interactions with groups of similar retail institutions. The overall consumer satisfaction construct was operationally measured using indicators: a multiattribute scale and a semantic-differential scale. Life satisfaction was conceptually examined through the use of quality-of-life and gerontological theoretical perspectives and was defined as an aggregate well-being level or satisfaction-attitude state of an individual determined by a variety of personal and environmental influences. This construct was operationally measured through the use of three indicators, two scales adapted from the quality-of-life perspective and one scale adopted from the gerontological perspective. The two constructs, overall consumer satisfaction and life satisfaction, were conceptually linked using attitude-hierarchy theory. It was hypothesized that (1) overall consumer satisfaction is positively related to life satisfaction of the elderly, and (2) each marketing sub-domain involved in overall consumer satisfaction is positively related to life satisfaction of the elderly. A survey instrument was designed, pretested. and employed on a sample of southwestern Virginia elderly using a group interview data-collection procedure. The statistical techniques employed to analyze the data collected included: Pearson Product-Moment correlations, alpha-coefficient reliability analyses, Costner's Multiple Indicator consistency analysis. t-tests, canonical correlations. and multiple regression analyses. Generally, the hypotheses were moderately supported by the results. The dissertation concludes with a discussion of the study's limitations. contributions, and implications as they related to marketing theory and managerial practice. / Ph. D.

In this work, an evaluation of a number of quasi-Newton algorithms and strategies for sparse, symmetric Hessian matrices was performed. It was shown how these quasi-Newton algorithms could be applied to the unconstrained minimization of a nonlinear function as well as a nonlinear least squares approach to solving a system of nonlinear equations. The best of these algorithms were evaluated for a problem with a fairly large number of degrees of freedom with a large load increment. From this study it is concluded that the proposed quasi-Newton method with the double dogleg strategy and an automatic control on Hessian evaluations is the best algorithm for all of the problems considered in this investigation. The algorithm had no difficulty converging to solutions regardless of the size of the model and regardless of the size of the load or time step. The advantage of being able to take large load or time steps may lie in those problems which involve the location of critical points (limit or bifurcation points) of structures with minimal computational effort. All the algorithms which utilized the double dogleg strategy were consistently better able to converge to the solution - a clear validation of the globally convergent property of the double dogleg strategy. Finally, the usefulness of the double dogleg strategy in solving a system of nonlinear equations via the nonlinear least squares approach and in locating multiple equilibrium configurations using deflation speaks for the versatility of the proposed algorithm. In conclusion, the quasi-Newton algorithm proposed in this dissertation is both robust and efficient for small as well as large scale problems of matrices are exploited. Because sparsity and symmetry the algorithm does not place unreasonable demands on core storage requirements. Furthermore, using the deflation technique with tunneling the algorithm can be extremely useful for post-buckling response studies of structures involving many stable and unstable branches. / Ph. D.

The application of wind power in various fields of energy requirements has been examined. Specific applications of the three broad classes of wind machines - Small, Intermediate and Large-scale, have been evaluated. Two methodologies were developed which could compute the amount of wind power required of existing Wind Turbine Generators (WTG) when placed in two sites in Virginia. The impacts of placing multiple WTG's in clusters to get higher power levels have been examined in details. A wake interference model has been included to calculate the amount of power reductions in downwind WTG rows. The advantages evolving out of site dispersal were also investigated. In general terms, arrays of wind farms produce some firm capacity because of the diversity of wind at the dispersed sites. Mostly, arrays of multiple sites tend to fill up the low power output levels of an individual site during the day. Besides, the output from an array consisting of a total of N wind machines, will be more than the output from an identical number of machines in a single site. These aspects of site dispersal have been discussed. The studies of Clusters and Arrays have been extended to utility interface. Two separate models - an Individual Site model and a Dispersed Site model have been considered for integration. Capacity credit earned for each case was investigated in details using a Reliability model. Wind power was also looked at from the competition against conventional expansion plants point of view. The economics of wind power in terms of capacity and operational cost savings were also examined. The problems arising out of a possible integration of wind machines have been pointed out and some solutions have been suggested. Computational results are presented in details from the major studies and recommendations for further work have been discussed. / M.S.

Prices paid for yearling rams were influenced (P < .001) by TSC, BT, YW and FW. The importance of YW increased with time, while the role of TSC declined in later time periods, suggesting that buyers were willing to pay more for superior performance and less for subjective conformation and type in later years than when the test began. A larger ram with an equivalent performance record was worth more than a smaller ram. The relative importance of FW and YW in defining price changed. In early years superiority in both traits was worth approximately the same, while in later years a higher YW brought about 2 1/2 times the premium of the same increase in FW. Prices paid for ram lambs were affected by TSC, BT, DG and FW, but the time period involved was too short to draw conclusions concerning changes in their relative importance. Phenotypic trends for yearling rams' WW, FW, YW and DG were positive (P < .001), and rates of increase were different for breeds (P < . 001). The decrease in mean age of tested rams and the increase in DG contributed to a quadratic trend in YW and supported adjustment of the data for age. Environmental trends, analyzed by a within-sire analysis of 1885 progeny of 4:30 sires, were not significant. Estimated genetic gains due to sires were: 1.06 ± .30 kg/yr for FW, 1.16 ± .32 kg/yr for YW, .36 ± .18 kg/yr for WW and .0037 ± .0021 kg/d/yr for DG. Phenotypic trends for the ram lambs were: .906 ± .198 kg/yr for FW, .00956 ± .000880 for WDA and .00212 ± .00228 kg/d/yr for DG. Yearling rams' OW and FW were correlated (P < .001), as were the same traits for ram lambs. The yearling correlation was much lower than that of the lambs, however (r = .89 vs r = .66). The correlation (P < .001) of OW and DG was .22 and -.20 for yearlings and ram lambs, respectively. Age and DG were correlated (P < .001) with a coefficient of -.20 for both yearlings and ram lambs. Yearling rams' SHT, HHT and BLGTH were highly correlated ( P < . 001), and cannon length was moderately correlated (P < .005) to SHT and HHT. Suffolks were taller than Hampshires and Dorsets. All three breeds made similar gains in SHT within the same year. SC generally increased over the course of the test. The SC of the black-faced breeds sometimes regressed from April to May, but showed gains from 0 to 2.15 ± .24 cm for the overall measurement interval. Dorset SC always increased the most with gains ranging from 2.08 ± .93 cm to 3. 88 ± 1.10 cm. Suffolk ram lambs were tallest in the first 2 yr and were similar to Hampshires in the third. Gains in ram lamb SHT over short intervals were negated by the shearing which took place before the second measurement. Mean gains over the lengthened 1982 test period ranged from 6. 04 ± .68 cm for Hampshires to 7.37 ± .36 for Suffolks. SHT was correlated ( P < .001) with weight, generally moderately correlated (P < .05) with DG and not usually correlated with age. Only the Suffolk lamb SC consistently increased from July to August. The SC of all breeds increased from May to August, Suffolks by the greatest amount. SC was correlated (P < .05) with SHT and generally was correlated (P < .005) with weight. Only the final SC was correlated ( P < . 005) with DG, and SC and age were not usually correlated. / M.S.

External responsiveness to food and non-food cues was studied among 306 obese and nonobese boys and girls ranging in age from 42 to 156 months. These subjects viewed 5 food and 5 non-food items and stated a preference between an immediate smaller and a delayed larger choice. When presented with food items, obese subjects were less able than the nonobese to delay an immediate smaller gratification to maximize reward magnitude. No significant differences were found between obese and nonobese children regarding nonfood delay choices. These findings are discussed in terms of ontogeny of externality, the cause of some forms of obesity. A significant age difference indicated that preschool children preferred more immediate gratification than did school children. This age difference is consistent with research on delay of gratification using a choice paradigm. / M.S.

A low-speed single-stage axial-flow compressor rig was configured for tests with variable-length upstream casing struts. Two axial strut lengths were tested for their effect on the inlet flow field and stalling characteristics of the compressor under clean and distorted inlet conditions. Data were obtained from one stationary and six blade-mounted high-response pressure transducers, and from a circumferentially- traversed directional probe. The distorted inlet flow field was changed significantly by the longer struts, which effectively sectored the inlet. Deep stall was not observed for this configuration. Rather, the stalling characteristic was changed to what is termed progressive rotating stall, in which six stable stall cells and significant increases in static pressure rise were noted. A new technique for determining the number of rotating stall cells from the frequency content of stationary and rotating reference frame signals is presented. Blade pressure response as a function of aerodynamic loading is detailed. / M.S.

The development of three colonies of Bombus fervidus (Fabricius) and two of Bombus pennsylvanicus (Degeer) was studied. Population levels and the production of males and young queens varied among colonies and between years. Mean longevity of worker bees decreased significantly toward the end of the season. Mean size of emerging worker bees increased significantly with time. The decreased survivorship may be related to the seasonal size increase of the workers, which would result in an increased proportion of foragers. Age-specific life tables and survivorship curves were developed for workers within colonies, and for workers in cohorts based on emergence date. An increase in brood developmental times occurred near the end of the colony cycle. In the two B. pennsylvanicus colonies, oviposition of fertilized eggs decreased during the transition period from worker to queen production, and large numbers of male-producing eggs were laid. At the time of queen production a sudden increase in size of emerging females occurred. Neither a gradual nor a sudden change in larva/worker ratio appears sufficient to explain caste determination. Rates of parasitization of bumble bee queens at three sites in Southwestern Virginia were studied. Endoparasites of spring queens included Locustacarus buchneri (Stammer) (Acarina: Podapolipidae), a mite infesting the abdominal air sacs; the nematode Sphaerularia bombi Dufour (Tylenchida: Nematoda), and gregarious braconid larvae, probably Syntretus sp. (Hymenoptera: Braconidae). Ectoparasites included hypopi of the mite Kuzinia americana Delfinado and Baker (Acari: Acaridae) and Parasitus spp. mites (Acari: Parasitidae). / M.S.

M.S.

Detoxification of compounds occurs in two phases. In phase I, a functional group on the toxicant is made available for subsequent Phase II reactions. In phase II, the functional groups are conjugated to a compound that will increase the solubility of the toxicant, enhancing its elimination. Uridine diphosphate glucuronyl transferase (UDPGT) is one microsomal enzyme involved in phase II reactions. It catalyzes the conjugation of toxic compounds with glucuronic acid in reactions in which uridine diphosphate glucuronic acid (UDPGA) is the donor substrate. A new purification procedure for UDPGT has been developed. This procedure includes a Polyethylene glycol fractionation, ion exchange chromatography with DEAE Bio-gel A and affinity chromatography with UDP-hexanolamine-Sepharose. The purification was monitored for three different substrates, bilirubin, 4-nitrophenol (PNP) and 7-hydroxy-4-methylcoumarin (HMC). For this last substrate, HMC, a new continuous fluorometric assay was developed. The purification fold and activity recovery, respectively, towards each substrate was as follows: bilirubin, 31 and 80%; PNP, 31 and 80%; and HMC, 24 and 60%. The significance of these results is discussed with reference to the activation of UDPGT in microsomes by detergents and the reactivation of purified UDPGT by phospholipids. / M.S.