Québec Université Laval, Bibliothèque 2015

Hylotrupes bajulus (L.) is a serious pest of seasoned softwoods. The female oviposits in the cracks and crevices of the wood, and the larvae can survive and feed in the wood for 2-10 years. The female H. bajulus has an elongated ovipositor comprised of the modified abdominal segments 8 and 9, intersegmental membrane 8/9, and pair of distal gonostyli. When not in use, the ovipositor is retracted within abdominal segment 7. The 8th abdominal segment forms the proximal end of the ovipositor. An internal apodeme attached to the base of the 8th sternite allows for extension and retraction of the ovipositor. The intersegmental membrane 8/9 makes up half the length of the ovipositor. The 9th abdominal segment, along with the gonostyli, comprise the dist3 l part of the ovipositor. The 9th sternum is split along the midline to form a pair of hemisternites. The gonostyli are comprised of basal coxites and apical styli. The gonostyli are the only remnants of the appendicular oviocsitor. Several types of sensory receptors are found on the ovipositor. Segment 8 has both long tactile hairs and short trichoid sensilla. Intersegmental membrane 8/9 has no vi sible sensory receptors. Segment 9 has campaniform receptors and short trichoid sensilla. The gonostyli have several types of sensory receptors including long tactile hairs, medium trichoid ser..silla, short trichoid sensilla, and basiconic receptors. The long tactile hairs and campaniform receptors are innervated by a single dendri te, thus functioning as mechanoreceptors. The medium trichoid are innervated by three dendrites, two of which extend into the lumen of the receptor. The short trichoid sensilla are innervated by five sensory neurons. The basiconic receptors are innervated by 1-3 dendri tes, depending on the type and location of the receptor. All three types of sensilla function as contact chemoreceptors, and may provide information on the suitability of the oviposition substrate. / Master of Science

Earlier research relating to the use of polyimides modified with metal-ion complexes and metal particles indicate that enhanced conductivity and adhesive strength can be achieved. This research evaluated the employment of metal-modified polyimides to achieve optimum conductance at an aluminum joint. Condensation and addition polyimides were employed. The modification of the polyimides occurred in two ways. The first method involved homogeneous doping of the condensation polyimides with metal-ion complexes. The second modification method involved heterogeneous doping of condensation or addition polyimides with particles of a nickel-aluminum alloy. / Master of Science

In this thesis, a system for studying human/computer interfaces is introduced. The human/computer interface provides several features, the most noteable of which is TOKEN COMPLETION. These features permit the user to define and/or redefine command tokens, define and/or delete synonym and noiseword tokens, and to establish a terminal environment. The terminal environment includes the ability to specify automatic comment blocking, token look-ahead, and to control the source of data input (keyboard, VMS file, or I/O buffer). The ability to token complete is based on a forest of generalized trees used to implement dynamic deterministic finite state automata (DDFA). These trees are built during IPL and loaded with command, synonym, and noiseword tokens, all of which are stored in separate VMS files. Synonym and noiseword translation is carried out in the lexical analysis process, thereby negating any need to specify these functions in the grammar of the language. Insertion and deletion into the forest may be executed at any time, permitting the dynamic definition and deletion of synonyms and noisewords. During synonym and/or noiseword definition, lexical analysis switches to a deterministic finite state automata (DFA) mode of operation. Upon completion, lexical analysis reverts to DDFA mode. A sample grammar is provided in the APPENDICES. The lexical analysis process is not tied into this grammar but rather is very general and will process any tokens stored in the command, synonym, and noiseword files. The sample grammar is LALR(1). / Master of Science

Two distinct forms of Red Crossbill (Loxia curvirostra) bred sympatrically in the southern Appalachians in 1983. The forms differed significantly in vocalizations and bill and body size, and the members of each of 20 male-female pairs were of the same size class. One of the forms from Virginia has been tape recorded in western North America in 1983 and in previous years, showing that vocal classes are not local dialects. Evidence presented here suggests that forms of Red Crossbill are not subspecies as is currently recognized, and that they behave as biological sibling species. / Master of Science

Field collections of grasshoppers (Orthoptera: Acrididae, Tetrigidae, and Tettigoniidae) from twenty hayfield and pasture sites in twelve counties in Virginia were made in 1979 and 1980. Fifteen Acrididae, two Tetrigidae, and six Tettigoniidae species were found among the 20,793 grasshoppers collected. Melanoplus femurrubrum femurrubrum (DeGeer) dominated the acridid fauna in both years, comprising 76.0 and 86.97 in 1979 and 1980, respectively. Two collection methods, sweepnetting and drop trapping, were used. It was assumed that the drop trap gave an absolute estimate of population densities and that discrepancies between the two collections were due to failure of sweepnetting to reliably sample the complex. Sweepnetting was found to bias against Acrididae in favor of the tettigoniidae in the complex studied. With species grouped by feeding preferences (quilds), sweepnetting sampled head (inflorescence) feeders above mixed-forb feeders, and mixed-forb feeders above grass feeders. Compared with other Acrididae, M.f. femurrubrum was over-represented in sweepnet samples above the composite of the other acridids. Within its quild its representation did not differ from the drop trap samples. Differences in the composition of the species complex from site to site were examined according to quilds based on diet, and were correlated with measurable properties or the vegetation. The proportion of head feeders was positively correlated with the plant height. Mixed-forb feeders were negatively correlated. Other vegetation properties (grass/forb ratio and percent of ground cover) were themselves highly correlated with plant height, and yielded no patterns that were as strong as those with plant height. / Master of Science

The relationships between ferric iron content and the P-T-fH₂ conditions of formation were examined for two biotite compositions: annite (K₂Fe₅Al₄Si₅O₂₀(OH)₄) and siderophyllite (K₂Fe₆Al₂Si₆O₂₀(OH)₄). The synthesized phases were annealed at fixed hydrogen fugacities using both the solid oxygen buffering technique of Eugster (1957) and the H₂ buffering technique of Shaw (1967). Resulting hydrogen fugacities ranged from 0.004 bars (at T = 400°C, P_T = 2 kb) to 51 bars (at T = 750°C, P_T = 1 kb). Ferrous iron contents of the annealed biotites were determined by wet chemical analyses. Total iron was determined by microprobe analyses to be equal to the stoichiometric values. The data confirm the predictions of Hazen and Wones (1972, 1978) that: 1) There is a structural limit imposed upon the Fe³⁺ content of annite due to the misfit between the octahedral and tetrahedral layers. This misfit requires a minimum of 11% Fe³⁺ in annite. 2) The steric misfit in annite can be corrected by a substitution of Al^vi + Al^iv for Fe^vi + Si^iv, so that there is no Fe³⁺ in siderophyllite at high hydrogen fugacities. A model relating Fe³⁺/Fe²⁺ ratios, fH₂, and T is proposed. The model accounts for the amount of Fe³⁺ needed to correct the steric misfit in annite and allows for variation in Fe, Al, and Mg contents among biotites. A simple oxidation-reduction reaction is used to relate changes in the non-steric ferric iron to hydrogen fugacity and temperatures for the Fe-Mg-Al biotites. The equilibrium constant for the reaction can be expressed as: (1) log K= 3607.2/T - 4.47 where, depending on composition, K is expressed as follows and R is a constant proportional to the U structurally required iron. (2) Al^vi/0.3 + Mg/0.72 ≥ 1, K = Fe³⁺/Fe²⁺ fH₂^1/2 (Al^vi + Mg ≥ 1) (3) Al^vi/0.3 + Mg/0.72 > 1, K = Fe³)/Fe²⁺ - (1-Al^vi-MG) fH₂^1/2 (Al^vi + Mg < 1) (4) Al^vi/0.3 + Mg/0.72 < 1, K = [Fe³⁺/(Fe²⁺ - (1-Al^vi-MG)) -0.185] fH₂^1/2 (Al^vi + Mg < 1) / Master of Science

Surface and bulk properties have been studied in terms of composition and morphology of siloxane containing block copolymers and their blends with homopolymers. X-ray Photoelectron Spectroscopy (XPS) has been used to obtain the compositional information from the top 60 angstroms or so at the surface. Transmission Electron Microscopy (TEM) was utilized to probe the bulk morphology. An attempt is made to compare the bulk and the surface and find possible mechanisms governing them. It is found that solvent-cast neat block copolymers have a uniform layer at the surface that is rich in siloxane whereas their bulk has a microphase-separated domain structure. In case of blends, siloxane enrichment is quite pronounced even at bulk concentrations as low as 0.05% w/w siloxane. Amount of surface siloxane as a function of bulk content is studied with the help of XPS. At the same time, the bulk morphology of these blends is studied by TEM. The changes occurring in the surface and the bulk are found to have similar patterns. It is shown that the observed surface behavior may be related to the bulk morphology. Molecular weight of the blocks in the copolymers is found to be a very important parameter governing both the surface and the bulk properties in the neat copolymers as well as their blends. / Master of Science

In this study, an instrument (Hutchins Behavior Inventory or HBl) was designed to measure components of the TFA System. The HBI was given to 328 college psychology students to measure reliability. Internal reliability scores for thinking, feeling and acting ranged from .780 to .980; test-retest reliability scores ranged from .710 to .930. / Master of Arts

The ability to generate a crossflow vortex pattern on a swept flat plate, that is typical of swept-wing flows, is presented. A swept flat plate with an elliptic leading edge is mounted vertically in the VPI&SU Stability Wind Tunnel opposite to a swept wall-bump; along with floor and ceiling fairings that duplicate the inviscid streamlines. The resulting pressure gradient over the plate produces a crossflow vortex structure. Detailed three-dimensional measurements, made within the boundary layer using hot-wire anemometry, are supplemented with different flow-visualization techniques. Freestream measurements are carried out to find the variation of the velocity vector along the model and comparisons are made with the theory showing good agreement. Spanwise measurements are conducted within the boundary layer and show a steady vortex structure. Boundary-layer profiles are taken using both a straight-wire and slant-wire probe in order to obtain the variation of the velocity vector in the region. The components parallel and perpendicular to the freestream velocity vector are extracted, and the perpendicular component is called the crossflow profile. These profiles are compared to the theory. Shape factors and crossflow Reynolds numbers are obtained and analysed. Two types of flow-visualization techniques are used in the tests. One is the "smoke-wire" technique, where streaklines inside the boundary layer are visualized. This method is not successful in visualizing any vortex structure in the boundary layer. Therefore, the second method was employed: a sublimation technique using trichlorethane and naphthalene is used to visualize the variation of the surface shear stress. A uniform pattern of streaks aligned approximately in the potential flow direction is observed. This pattern has a wavelength on the order of one centimeter which agrees quite well with the theoretical model. / Master of Science