One of the most popular methods for achieving control of the Red Imported Fire Ant, Solenopsis invicta Buren, is through the use of broadcast baits. Several factors contribute to bait efficacy, one of which may be particle size. The goals of these laboratory studies were to determine particle size and bait preference using Advance Select Granular Ant Bait and Advance Carpenter Ant Scatter Bait, determine the effect of starvation on bait removal and recruitment to Carpenter Ant Scatter Bait, and determine if any correlation existed between head capsule width and particle size selected. Experimental colonies removed significantly more 1400-2000 μm particles of Select Granular Ant Bait, while ants foraging on Carpenter Ant Scatter Bait preferred 1000-1400 μm particles. Mean number of ants present at bait mirrored results from bait removal test. Ants displayed a preference for Carpenter Ant Scatter Bait based on mean number of ants present at bait for the 10-d foraging period. For starvation assays, significant differences in bait removal and number of ants present occurred in the 0-d group. Ants starved for 5 d removed significantly more bait of all particle sizes, and removed greater amounts of 1000-1400 μm Carpenter Ant Scatter Bait than other sizes. Head width reliably predicted particle size selected, but the linear model explained very little of the observed variation for ants foraging on Select Granular Ant Bait (R2 = 0.043) or Carpenter Ant Scatter Bait (R2 = 0.047). This study supported the significant role of bait size and starvation period in S. invicta bait preference, and demonstrated how size preference may vary depending on bait type.

Thesis--University of Oklahoma. / Includes bibliographical references (leaves 45-46).

One of the most important issues in suspension polymerisation process is the control of the final particle size distribution (PSD) as this is an indicator for both quality and financial matters. For polymer manufacturers, a narrow PSD is always welcome. The conventional reactors, e. g. stirred tank reactors, generally produce particles of a rather broad PSD. As a result, to explore a new type of polymerisation devices becomes a challenging task. The objectives of this PhD study are to apply a novel mixing apparatus, the oscillatory baffled reactor (OBR), to batch polymerisation of MMA and Styrene (crosslinked) and to characterise all the major aspects of the OBR involved in the pioneering work, with a view to assessing its potential for industrial applications. In order to carry out such investigations, a 1.2 litre batch jacketed OBR system with temperature control and on-line data acquisition units was designed and built. In addition, an off-line image capture system was set up f or droplet studies. From heat transfer study in the OBR, it was found that the temperature profiles across and along the reactor were uniform and a heat transfer correlation was obtained. The oil-water dispersion in the OBR was then investigated for various baffle designs, dispersed phase fractions and the levels of surfactants, enabling the optimal baffle type and parameters to be identified. In order to understand the droplet behaviour in the OBR, the droplet size distribution (DSD) was examined on dispersion uniformity, oscillation time, operational conditions, baffle thickness and the level of surfactant addition. It was found that the DSDs were very uniform within the reactor and the oscillation frequency and amplitude had the same effect on controlling the DSDs. Finally, a series of PMMA and PS tests were successfully conducted in the OBR, indicating that the polymer PSD can be controlled by adjusting both oscillation conditions and the baffle orifice diameter and that the OBR has the potential to produce uniform polymer particles at high oscillation frequencies. A correlation between droplet sizes with no reaction and final polymer particle sizes was established, which can be used to predict the final polymer sizes.

No description available.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1952. / Typescript. Includes abstract and vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 104-107).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1951. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 96-98).

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Ph.D.

No description available.

No description available.