<p> Social learning, defined as learning from other individuals has been well studied in vertebrates and social insect species. I used fruit fly egg laying site selecting as a paradigm to test for social learning in a non-social insect. Focal females that experienced novel food together with mated females (models), who had laid eggs on that food, subsequently exhibited a stronger preference for laying eggs on that food over another novel food than focal females that experienced the same food alone. This socially influenced learning was also observed when focal females experienced both foods, one with mated models and their eggs and one alone. In contrast to the strong effect of a food with mated models and their eggs, neither a food with virgin models nor the aggregation pheromone (cVA) alone generated socially influenced learning. These results provide the first evidence for social learning about egg laying substrate in fruit flies. Further research utilizing fruit flies as a model system may help us gain a better understanding of the evolution and neurogenetics of social learning.</p> / Thesis / Master of Science (MSc)

Yes / Bond between substrate and overlay concretes is a key factor for the success of the repair method and significantly influences the structural performance of the repaired element. This study investigated the effect of fly ash and the surface preparation method on the bond strength of repaired concrete after exposure to high temperatures, that has not been comprehensively studied in the literature. For this purpose, overlay concretes containing 0, 5, 10, 15, and 20% fly ash as a replacement by weight of cement were cast on the original concrete surface prepared by four methods namely, as-cast, wire brushed, grooved and grooved-wire brushed. The bond strength of the interface between concrete substrate and overlay concrete was evaluated after exposure to 23, 200, 400, and 600oC temperatures for 1 hour. The results showed that partial replacement of cement by fly ash in the overlay concrete increased the bond strength of repaired concrete by up to 71%, depending on the amount of fly ash used, surface preparation method, and the temperature to which the sample was exposed. The maximum increase of bond strength was recorded for concrete containing 20% fly ash when the wire brushed preparation method was adopted at temperature of 200oC. However, surface preparation was the most influential parameter, achieving a bond strength gradual increase in order from as-cast, wire brushed, grooved to grooved-wire brushed methods. The results also showed that for most of the samples having similar surface preparation and the same percentage of fly ash, bond strength decreased with the increase of exposure to temperature; for example, for overlay concretes without fly ash, in as-cast and wire brushed surface preparation methods at temperatures of 400 and 600 oC, the bond strength has reached zero. On the other hand, for grooved and grooved-wire brushed surface preparation methods, the bond strength reduction was about 63%, when temperature increased from 23 to 600oC. / The full-text of this article will be released for public view at the end of the publisher embargo, 12 month from first publication.

No description available.

No description available.

A study of the nutritional requirements of adult house flies has shown that liquid diets of natural and purified products are capable of supporting continued oogenesis. Chemically defined liquid diets containing nine 1-amino acids fed to newly emerged female flies were necessary for ovarian maturation and oviposition. Water, salts and carbohydrate were the other basic dietary requirements for this process and for survival. The addition of cholesterol to this synthetic diet also influenced fecundity. For the maturation and oviposition of more than one ovarian cycle the synthetic diet had to be supplemented with the amino acid 1-methionine, certain B-vitamins and nucleic acid bases. Flies fed diets deficient in these supplements showed a lower fecundity and survival. A dry synthetic diet was developed which supported egg production. / Thesis / Doctor of Philosophy (PhD)

Yes / Increasing infrastructure growth has forced the construction industry to look for wasteful, cheap, and suitable materials for construction. An investigation into the geotechnical utilization of fly ash was carried out in the present study. Practical applications normally involve the use of large quantities of fly ash, so proper mixing of the fly ash with other materials may not be significantly achieved. Therefore, the present paper investigates the behaviour of a fly ash–bentonite layered system with different ratios. The physical properties and chemical composition of fly ash and bentonite were determined. SEM and energy dispersive X-ray experiments were also used to investigate the morphology and phase compositions of fly ash and bentonite. A series of consolidated undrained (CU) triaxial tests on fly ash–bentonite were carried out to investigate shear strength characteristics. Fly ash (F) and bentonite (B) were used in the following ratios: 1:1 (50% F:50% B), 2:1 (67% F:33% B), 3:1 (75% F:25% B), and 4:1 (80% F:20% B), with different numbers of interfaces (N), i.e., 1, 2, and 3 for each ratio. The deviator stress and cohesion value were found to increase with the number of interfaces for each ratio. The angle of shear resistance changed marginally with the increase in the fly ash–bentonite ratios and varying interfaces.

<p>Validerat; 20111223 (anonymous)</p>

Results are reported from a series of experiments simulating the combustion and expansion processes of a heavy-duty combustion turbine engine burning a heavy residual fuel oil. The tests were carried out in a turbine simulator device, consisting of a combustion chamber and a turbine first-stage nozzle cascade sector. Both film, air-cooled and closed-circuit, water-cooled nozzle sectors were tested. These sectors were four-vane, three-throat sections with throat cross-sectional areas of approximately 50 (10⁻⁴) m². The test fuel was simulated by adding the appropriate contaminants to no. 2 fuel oil. A series of seven full-length tests were performed, ranging in length from 22.5 to 88.2 hours. Four of the tests involved the watercooled nozzle sector and the remaining three used the air-cooled nozzle. The principle objectives of the tests were to assess the rate at which ash accumulates in the turbine nozzle and the relative difficulty in removing these deposits. The variable used to evaluate the extent of the ash deposit on the nozzle was the effective throat area, determined using the calculated gas flow rates, turbine nozzle inlet temperature, and the measured combustion chamber pressure. The parameters varied in the test program, other than the nozzle sectors, were the gas temperature and the gas pressure. The gas pressure variations served to vary the gas path surface temperatures at constant gas temperature. The test conditions were nominal turbine firing (nozzle exit) temperatures of 1283 and 1394 K and combustor pressures of 3 and 6 atmospheres. A 2-to-l pressure ratio was maintained across the nozzle to insure sonic conditions at the throat sections. With the exception of one test, the data show that the deposit rates in the water-cooled turbine nozzle were lower than in the air-cooled nozzle. The effect of increasing the gas temperature was to dramatically increase the ash deposition rates. Decreased gas pressures (and hence surface temperatures) resulted in reduced deposition rates. Ash cleanability was enhanced by water-cooling. Heat transfer data were analyzed from the water-cooled tests and gave significant insight into the ash deposit formation and removal phenomena. One of the more significant conclusions drawn from these data was that the major portion of the effective area decrease observed in a turbine nozzle because of ash deposits is due to the pressure face deposits. A computer simulation of a combustion turbine engine was developed to aid in the evaluation of the turbine simulator test data. Results from field tests of full-sized production engines burning residual oil were used in the simulation to determine the relationship between the extent of ash deposition (throat area reduction) and turbine efficiency. This result was then combined with data from the turbine simulator tests to produce a real-time computer simulation of full-sized combustion turbine engines having air- and water-cooled first-stage turbine nozzles. It was found that water-cooling of the turbine nozzle would result in an increase in engine availability of 27 per cent when operating on heavy residual fuel oil. / Ph. D.

no abstract provided by author / M.S.

Preliminary experiments in Virginia by Wallace and Turner (1961) on face fly control indicated that there was some promise using low-level feeding of a chemical such as ronnel in a mineral salt mixture as a larvicide. In cooperation with the Moorman Manufacturing Company and Mr. H. C. Stuart of Elk Garden, Virginia, a large scale experiment was initiated in the spring of 1962 . Approximately 1600 head of cattle in 23 pastures were utilized in this experiment. All of the pastures received a mineral salt mixture containing 5.5 percent ronnel with the exception of two pastures on the perimeter of the treated area that received no ronnel and were used as checks. Adult and larval counts were made on 7 of the 23 treated pastures and both of the untreated pastures. Results indicated that: (1) In spite of good larval control adult fly counts remained high, especially in treated pastures near untreated areas. Apparently the face fly has a natural tendency for dispersion, and, therefore, area control by low-level feeding of salt containing a larvicide is difficult. (2) When the consumption of ronnel remained above 5.5 mg per kg of animal body weight per day, larval control was above 95 percent. (3) During hot, dry periods animals reduced their salt consumption and this resulted in decreased larval control. (4) When salt boxes were placed in areas where cattle were seldom seen to frequent, salt consumption was lowered, as was larval control. / Master of Science