The electrical-producing windmill industry boomed during 1983. It was estimated that"unit sales during 1983 would be twice those of the prior 10 years combined." Most of the activity has been in the development of windfarms in the western states and Hawaii. The boom is largely due to (1) tax breaks given to alternative energy producers and (2) the Public Utilities Regulatory Policies Act (PURPA) of 1978. PURPA requires public utilities to purchase electricity from small producers. In many instances, the investors main interest was the tax break and as a result the development was of inferior quality.⁴⁰ Electrical-producing windmills are delicate machines in that lightweight components are used to move large forces. Domestically, there are about 50 manufacturers of electrical-producing windmills. Most of these manufacturers have just entered the field. As such, they have not had time to perfect their machines. And as a result, 50% downtimes are not uncommon and failures are frequent.⁴⁰ In the mid-70's, the U.S. Department of Energy (DOE) embarked on a large scale program for the research and development of windmills. In 1982 the program was drastically cut by the Reagan administration. While the program was in full swing, significant steps were made in 129 130 developing safe, reliable wind energy systems. Wind energy systems could probably supply up to ten percent of the nation's annual electrical demands, but one to two percent is a more reasonable goal. For this to happen the government must not cut its existing financial incentives, existing windfarms must prove to be economical, private manufacturers must develop high quality wind energy systems, and windfarms must be developed at sites throughout the country. / Master of Engineering

Rooted stool-bed layers of Malling Merton (MM) 111 apple trees were container-grown in a greenhouse and trained to a single shoot. When shoot length averaged 73 cm, the following treatments were applied: a) check, untreated (CK); b) tipped (shoot apex removed) and top 1/2 of shoot disbudded (T-DB); c) top 1/2 of shoot disbudded and defoliated (UT-DB-DF); d) tipped, and top 1/2 of shoot disbudded and defoliated (T-DB-DF); e) pruned at mid-shoot (P); or f) pruned at mid-shoot and disbudded (P-DB). Treatments UT-DB-DF, T-DB-DF, P, and P-DB delayed the eventual decline in net photosynthesis (Pn) and total chlorophyll content exhibited by the check. The delay in the decline of Pn and total chlorophyll content was maintained for the longest period in the UT-DB-DF, T-DB-DF, and P-DB treatments. Maintenance of Pn and chlorophyll levels following pruning or defoliation appears to result from an increased root : shoot ratio at treatment rather than an increased demand for photosynthates by subsequent growth. Treatment responses of Pn and total chlorophyll content were similar so that Pn per unit chlorophyll showed no treatment differences. Removal of leaves by either pruning or defoliation reduced total dry weight of the tree whereas tipping had no effect. Final dry weights of the basal stem, roots, and shank were reduced by pruning or defoliation. Lateral shoot growth induced by pruning caused an initial decrease in the shank diameter and root and shank dry weights of potted apple trees. / Master of Science

A novel concept (called “heat tray”) is proposed for heat recovery from hot gases and for heat management in exothermic catalytic reactions, which involves a supernatant gas (S-gas) flowing over a shallow fluidized bed of solids. This thesis presents the results of bench-scale and pilot-scale experimental studies that quantify heat transfer between the S-gas and the shallow fluidized bed. A fractional-factorial design of experiments was performed on two heat-tray systems using three different results showed that fine fluid cracking catalyst (FCC) particles out-performed larger alumina spheres as a fluidized solid. Heat transfer coefficients between the supernatant gas and the shallow fluidized bed approached 440 W/m²-K using FCC. Various S-gas inlet nozzle configurations were studied, with a nozzle height equal to one-half of the static bed height (0.051 m) giving the best results. The study showed that short heat-tray lengths (<0.8 m) are desirable and that S-gas redistributors are needed to compartmentalize the unit. An economic analysis showed that the proposed heat tray would be economically feasible for adaption as a boiler feedwater preheater in a small steam-generation facility, using boiler combustion gases as the S-gas. The payback time for the system would be as short as 1.9 years when used continuously. The heat transfer results from a S-gas to a flowing shallow fluidized bed represent the only data reported thus far, and have led to a better understanding of the new shallow fluidized-bed system for heat-exchange applications. / Master of Science

An investigation to determine the low-speed lateral-directional characteristics of a generic 74-degree delta wing-body configuration employing the latest generation, gothic planform vortex flaps has been conducted. In addition, the theoretical estimates from VORSTAB were compared against experimental data to aid in documenting this new method. VORSTAB is an extension of the Quasi-Vortex-Lattice Method of Lan which empirically accounts for vortex breakdown effects in the calculation of longitudinal and lateral-directional aerodynamic characteristics. The experimental results indicated that leading-edge deflections of 30 and 40 degrees significantly reduce the magnitude of the wing effective dihedral relative to the baseline for a specified angle of attack or lift coefficient. For angles of attack greater than 15 degrees, these flap deflections reduce the configuration directional stability despite improved vertical tail effectiveness. Asymmetric leading edge deflections are shown to be inferior to conventional ailerons in generating rolling moments. Asymmetric leading-edge deflections are effective in producing side force at moderate to high angles of attack. VORSTAB lateral-directional calculations provide ballpark estimates at low to moderate angles of attack. The theory does not account for vortex flow induced, vertical tail effects at high angles of attack and should not be used for this angle of attack region. The empirical formulae for predicting vortex burst effects are not reliable in their present form. Although the basic trends are correct, the magnitude of the predicted vortex burst effect is typically over-estimated. / Master of Science

This research was conducted over the period of three quarters at Virginia Tech. The goal was to develop an instrument that was both valid and reliable for the purpose of exempting qualified, experienced students from the basic apparel construction course and allow them to begin with the advanced course. Resulting classes would be more homogeneous and, therefore, could be more effectively taught. Data on test questions was available from prior administrations of a clothing construction knowledge test. Test items that pertained to current course content and with acceptable difficulty and discrimination indexes were retained for use. The test was developed in three phases. The resulting test would be adaptable for use by other institutions because of the methodology used to develop it. The course behavioral objectives were first examined and assigned a percentage corresponding to the amount of class time devoted to each objective. Individual learning concepts were then analyzed and listed under the objective they each pertained to. Once this categorization was accomplished, the learning concepts were each ranked according to importance and complexity within their respective objectives. This ranking was then used to decide how many test items should pertain to each concept. The exemption test developed through this procedure encompassed all course objectives and assured a representative sample of the course content. The final test was determined to be both valid and reliable. Its adoption as an exemption test was recommended with minor revision. / Master of Science

Ed. D.

No description available.

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