Vocalizations and singing behaviors of Rufous-crowned Sparrows, Rufous-winged Sparrows, and Cassin's Sparrows were analyzed, described, and compared. For comparative purposes, data from previously studied Five-striped Sparrows were also included. Ten, 5, 3, and 6 types of calls were present in the repertoires of Rufous-crowns, Rufous-wings, Cassin's, and Five-stripes, respectively. Songs were sung from the ground, or from a variety of perch heights. Only Cassin's and Rufous-crowns regularly sang flight songs. Cassin's Sparrows sang a higher percentage of flight songs before nesting than after, but time of day did not affect the occurrence of flight songs. A Discriminant Function Analysis performed on six song parameters showed that the species differed significantly in the parameters measured. Song length proved to be of primary importance for discriminating the species' songs. From 8 male Rufous-crowns, 3320 songs were recorded. Fifty-one different song types composed of 259 different note complexes were found in this species' repertoire. The average song repertoire size for an individual was 12. Nine songs and 84 note complexes were shared among individuals. From 14 male Rufous-winged Sparrows, 3593 songs were recorded. Fourteen different song types were found; all individuals potentially may sing all fourteen song types. Nine hundred sixty-nine songs were recorded from 18 Cassin's Sparrows, of which 15 different songs were recognized. Individual repertoires consisted of an average of 3 song types, thus some sharing did occur, but no individuals shared the same repertoire. Rufous-crowns varied their singing rate regardless of the song type used, and singing rate was not related to time of day. Rufous-wings frequently engaged in counter-singing bouts with males alternating and matching song types. Singing rate appeared to be affected by the song type being sung. Singing rates of Cassin's Sparrow songs delivered from perches were sung at a faster rate than those sung only in flight, but there was no relation between singing rate and variation in number of different song types employed in a bout or the proportion of flight versus perch songs. The vocalizations and singing behavior of the four Aimophila species were dissimilar in many respects, and suggested possible functions of the diverse singing behaviors exhibited by these species were discussed. / Ph. D.

The purpose of this thesis project was to design, construct and evaluate the performance of a high temperature continuous-run electric arc wind tunnel. A pilot model of such a facility was designed assuming that equilibrium air was the working gas. The pilot model facility was constructed and consisted of the following components; arc chamber, stagnation chamber, nozzle section, test and diffusor sections. In the arc chamber, the air passes through the positive column of an electric arc there-by raising its stagnation temperature before entering the stagnation chamber. Also included in the design and construction were water cooling and waste disposal systems, air supply and vacuum systems, and electric arc power supply system and control. An examination of tests performed in the electric-arc facility showed that a low density supersonic flow with a stagnation temperature of approximately 10,000 F could be produced. The power level for this flow was 36 kw; however, with an expected increase of power to 72 kw the stagnation temperature should be raised to 15,000 F. Since no valid technique for measuring temperatures of this magnitude has been perfected to the author's knowledge, these temperatures were calculated according to a method as outlined in the present thesis. The present facility will present an opportunity for study in such topic areas as (1) Aerodynamic Ablation, (2) Magnetoaerodynamic studies and (3) Qualitative studies of chemically reacting gas flows. / 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

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

Semiochemicals released from logs infested by southern pine beetle (SPB), <i>Dendroctonus frontalis</i>, from a total of eight infestations located in Texas, South Carolina, and Virginia were collected four to eight days after initial attack. The quantities and chiralities of most semiochemicals, as analyzed by gas-liquid chromatography, showed geographic and temporal variations. Changes in the quantities of α-pinene (aP), frontalin (F), and <i>endo</i>-brevicomin (eB), are believed to result from responses of the host and the beetle to each other's activity at a given time and differences in their respective health. The chiralities of aP, F, and eB at all locations generally remained stable over time, yet variation across the insect's geographic range, particularly for aP and F, is believed to be due to genetic variation of individuals. Geographic and temporal variations in the quantities and chiralities of <i>cis</i>-verbenol (cV), <i>trans</i>-verbenol (tV), and verbenone (V) are presumed to be due to the multiple pathways of origin (SPB, autoxidation, and microorganisms). Analysis of the same semiochemicals isolated from hindguts of individual beetles from Texas, South Carolina, and North Carolina showed quantities of cV and tV to be substantially greater in females than in males; whereas, males contained much greater amounts of V. Geographic differences were found in quantities of tV and V in both sexes and in aP and F in males only. The chiralities of most semiochemicals present in SPB hindguts differed markedly from those released from infested logs. Males produced predominantly (+)-F and (-)-eB, (-)-cV, and (-)-V; however, the chirality of tV varied considerably among areas. In contrast, females produced predominantly (+)-cV and (+)-V and (-)-F, (-)-eB, and (-)-tV. The (+) enantiomer of aP predominated in both sexes, but the proportion of (+ )-aP was generally lower than that released from SPB-infested logs from the same areas. Geographic differences in chirality of tV and V were significant in males and for eB in females. In laboratory trials, aP autoxidized under ambient temperatures to form tV, myrtenol (M), V and to a lesser extent, cv. Both the quantities and chiralities of these compounds were dependent on the chirality of the aP precursor. Significantly greater amounts and proportions of the (+) enantiomer of each compound were produced when (+)-aP was predominant than when the antipode of the precursor was predominant. The extent to which autoxidation products playa role in bark beetle behavior is expected to be dependent on the proportion of aP in pine resin and its chirality present in a pine species. The information gained from this research was used to elaborate on previously proposed behavioral sequences occurring during the mass attack of host trees by SPB and to suggest new avenues to improve the use of semiochemicals in pest management efforts. / Ph. D.

The purpose of this thesis is to approach a partial theoretical understanding of the design of lamella structures and to determine the economic merit of the lamella structure as a structural steel hangar. A survey revealed no literature that discusses the design of lamella past the concept that the lamella could be designed as independent arches. In this thesis the analysis and design of the main structural steel members are attempted. In the analysis of the hangar it is assumed that the intersecting arches will not interact under load. The effect of the error of this assumption is minimized by furnishing partial support to the free edge of the lamella system by the use of an arch that spans the structure at the transverse edge. The effect of this edge arch is to cause the maximum stresses to occur in the interior of the lamella system where the interaction is minimized by the symmetry of the system. The method of analysis is a combination of graphic statics and virtual work. Graphic statics was used to determine the pressure line of the arches and virtual work summations were used to determine the redundant loads and reactions. At the conclusion the structure is compared on a tonnage of steel basis, with a structure of the same approximate size composed of steel rigid frames. / Master of Science

The superbly exposed Rocknest Formation, Wopmay Oroqen, N.W.T., Canada, is an early Proterozoic (l.B9 Ga) passivemargin carbonate platform. It is an eastward-thinning prism, 0 to 1,100 m thick, extending for over 220 km parallel to strike, and over 200 k.m perpendicular to strike. It contains from west to east, slope, outer-shelf, shoaloomplex, and inner-shelf facies. Slope facies are rhythmites, megabreccias and rhythmite breccias. Outershelf faciea include stromatolitic reefal boundstone and backreef ooid/intraclast grainstore. Shoal-complex facies are shallowing-upward cycles of tufa, cryptalgalaminite, laminated dolosiltite/lutite, overlain by tepees, breccias and pisolite; these formed a paleotopographic high, restricting an eastern "lagoon" from western ocean. Innershelf facies are dominantly asymmetric, shallowing-upward cycles of "lagoonal" mixed carbonates and siliciclastics, that grade up into intertidal stromatolitic dolomites; cyclic facies pass eastward into non—cyclic siliclastics of central and eastern "lagoon". The shelf was terminally drovmed during attempted subduction of the margin. Individual cycles are correlatable for over 200 km parallel to strike and over 120 Ion perpendicular to strike. Cycles formed in response to small, asymmetric (rapid rise/slow fall) eustatic oscillaticns in sea-level (= 10 m). An alpine glacio-eustatic model accounts for the origin of cycles best. During sea-level rise, rapid transgression and submergence of tidal flats occurred along eastern margin of the shoal-complex, followed by eastward expansion of the shoal—complex, and slow progradation of tidal flats over lagoonal facies during sea-level fall. Computer modelling of Rocknest cycle types across the platform provides important information on absolute l sedimentation rates and lag times. / Ph. D.

Ph. D.

Ostertagia circumcincta, a parasitic nematode of sheep, known collectively with the O. trifuroata, the smaller trichostrongyles and several other worms of the same genus Ostertagia, as the "brown hair worms of sheep”, has held a rather obscure position in the evaluation of the importance of the sheep and goat parasites. This fact and their small size account for the elusive past of this nematode. The status of economic importance, however, to which O. circumcincta has now risen, not only in this state, but in the western section of the United States, Europe, New Zealand, and Australia, suffices as an explanation tor further researches bearing on the classification, anatomical organization and cytological study of this parasite. This paper deals quite briefly with the anatomy of the female Ostertagia circumcincta, and somewhat more in detail with the changes observed in the development of the germ cells from the primordial stage through the first cleavage division. 1. The primordial germ cells arise at the tip of the germ tube which lies just posterior to the oesophagus. 2. The period of growth following each stage in the development of the egg is accompanied by a fragmentation of the chromatin material before division takes place. 3. Chromatin strands make their first appearance in the secondary oocytes. 4. The chromatin strands condense to form six bivalent chromosomes or tetrads. 5. The six tetrads split to form twelve individual chromosomes then fuse to form six bivalents which are present when the egg enters the seminal receptacle. N=6 2N=12 6. The eggs remain in one-celled stage until they reach the seminal receptacle where fertilization takes place; immediately thereafter, that is to say, in the uterus. They begin their cleavage divisions. / Master of Science

This study was an investigation of loneliness among widowed elders using a model conceptually based on symbolic interaction theory. Symbolic interaction theorists contend that people are active, self-directing, and creative individuals who adjust to dramatic situational changes such as widowhood by defining the transition according to its symbolic meaning and their current perspective of the event. The loneliness model suggested that certain background characteristics, personality resources (morale and mastery), and perceived levels of social support would influence the sample’s perspective and definition of the social reality of widowhood, and thereby, serve to facilitate or impede the development of feelings of loneliness. In contrast to most studies of loneliness among widowed elders, this study included males (n=38) as well as females (n=135) and both short-term (6-24 months) and long-term (25-60 months) widowed persons. Participants were healthy, educated, unmarried community residents aged 69 to 91 years. In general, the sample was well adjusted with high levels of social support, morale and mastery, and low levels of loneliness. Data analyses included bivariate correlations, tests, and multiple regression. The regression analysis revealed that morale and the social provision of emotional attachment and morale were the strongest predictors of loneliness in the regression model (R²=.39). The results of the study partially supported the proposed model of loneliness. The findings also served to further substantiate Weiss's theory of relational provisions and the importance of various social provisions, especially attachment, in countering feelings of loneliness during widowhood in later life. / Ph. D.