The work outlined in this thesis describes how rheological techniques can be used to gain insight into the behaviour of complex hydrating systems. These techniques are currently used to elucidate interparticle interactions of concentrated colloidal dispersions. Those used here were stress relaxation, pulse shearometry and oscillation. These enabled parameters such as the dynamic moduli, relaxation moduli, relaxation spectrum and limiting moduli to be obtained. These all give a measure of the strength of interaction of the colloidal system under different conditions, without reducing these interactions by inducing flow. Calorimetric data was obtained for a hydrating cement paste. The particle and floc size of this cement was also measured. The data were found to be in accord with one another, and with current theories of the hydration processes of cement. In combination with the rheological parameters measured this enabled the extent and strength of attraction between the particles of a cement paste to be determined, as a function of the age of the paste. The adsorption characteristics of surfactant on cement were measured, as was the effect of surfactant on the particle and floc size of hydrating cement. Coupled with a measure of the rheological parameters of the cement-surfactant system, an understanding of the effect of surfactant on a hydrating cement paste was obtained. Similarly the effect of the addition of styrene-butadiene polymer latex particles, with and without excess added surfactant, was able to be determined. This information was obtained for hydrating cement pastes, both in the presence and absence of added polymer, at both ambient and non-ambient temperatures.

Financial analysts are an important group of information intermediaries in the capital markets. Their reports, including both earnings forecasts and stock recommendations, are widely transmitted and have a significant impact on stock prices (Womack 1996; Lys and Sohn 1990, among others). Empirical accounting research frequently relies on analysts' forecasts to construct proxies for variables of interest. For example, the error in mean forecast is used as a proxy for earnings surprise (e.g., Brown et al.1987; Wiedman 1996; Bamber et al.1997). More recent papers provide evidence that the mean consensus forecast is used as a benchmark for evaluating firm performance. (Degeorge et al. 1999; Kasznik and McNichols 2002; Lopez and Rees 2002). Another stream of research uses the forecast dispersion as a proxy for the uncertainty or the degree of consensus among analysts and focuses on the information properties of analysts (e.g., Daley et al. 1988; Ziebart 1990; Imhoff and Lobo 1992; Lang and Lundholm 1996; Barron and Stuerke 1998; Barron et al. 1998). In this paper I combine the two streams of research, and investigate how lack of consensus changes the information environment of analysts and whether the markets perceive this change. More specifically, I investigate the amount of private information in a divergent earnings estimate (i.e. one that is above or below the consensus), whether the markets react to it at either the time of the forecast release, at the realization of actual earnings, and whether Regulation Fair Disclosure has changed the information environment differently for high and low dispersion firms.

Odour emissions and instantaneous downwind odour plumes were measured on two 3000-sow swine farrowing farms located in a flat area of southern Manitoba, one farm (Farm A) with open earthen manure storage (EMS) and another (Farm B) with negative air pressure (NAP) covered EMS. Three commonly used dispersion models (ISCST3, AUSPLUME, and INPUFF-2) were used to predict downwind odour distributions on the two farms. Dispersion predictions were based on the measured odour emission data for each farm and on-site weather data recorded by a portable weather station. The peak-to-mean ratios of downwind odour intensity were computed from field odour intensity measurements and analysed against averaging time, downwind distance, and atmosphere stability class. It was found that the average odour emission rate from the negative pressure covered earthen manure storage (NAP EMS) was negligible in comparison with the open EMS (0.3 vs 20.3 OU/ s-m2). Downwind odour intensity measured by trained human sniffers on Farm A with covered manure storage was significantly (P<0.05) lower than that on Farm B with open manure storage at 100 and 500 m, but the difference in odour intensity at 1000 m was not significant (P>0.05) between the two farms. A 46% difference in odour emission rate between Farms A and B resulted in a 14% difference in the separation distance for odour annoyance-free between the two farms. When three commonly used dispersion models, namely AUSPLUME, ISCST3, and INPUFF-2, were used to predict downwind odour from the farms, the percentage of agreement between model predictions and field measurements was adequate for downwind distances of 500 and 1000 m, but relatively low for 100 m for all three models. Since the long-distance (>1000 m) predictions are of more practical value, all three models were considered to be adequate in predicting odour downwind from the swine operations. The peak-to-mean ratios of downwind odour intensity were computed from field odour intensity measurements and analysed against averaging time, downwind distance, and atmospheric stability class. The peak-to-mean ratio of field odour intensity increases with averaging time and downwind distance, and unstable atmospheric conditions.

No description available.

No description available.

Odour emissions and instantaneous downwind odour plumes were measured on two 3000-sow swine farrowing farms located in a flat area of southern Manitoba, one farm (Farm A) with open earthen manure storage (EMS) and another (Farm B) with negative air pressure (NAP) covered EMS. Three commonly used dispersion models (ISCST3, AUSPLUME, and INPUFF-2) were used to predict downwind odour distributions on the two farms. Dispersion predictions were based on the measured odour emission data for each farm and on-site weather data recorded by a portable weather station. The peak-to-mean ratios of downwind odour intensity were computed from field odour intensity measurements and analysed against averaging time, downwind distance, and atmosphere stability class. It was found that the average odour emission rate from the negative pressure covered earthen manure storage (NAP EMS) was negligible in comparison with the open EMS (0.3 vs 20.3 OU/ s-m2). Downwind odour intensity measured by trained human sniffers on Farm A with covered manure storage was significantly (P<0.05) lower than that on Farm B with open manure storage at 100 and 500 m, but the difference in odour intensity at 1000 m was not significant (P>0.05) between the two farms. A 46% difference in odour emission rate between Farms A and B resulted in a 14% difference in the separation distance for odour annoyance-free between the two farms. When three commonly used dispersion models, namely AUSPLUME, ISCST3, and INPUFF-2, were used to predict downwind odour from the farms, the percentage of agreement between model predictions and field measurements was adequate for downwind distances of 500 and 1000 m, but relatively low for 100 m for all three models. Since the long-distance (>1000 m) predictions are of more practical value, all three models were considered to be adequate in predicting odour downwind from the swine operations. The peak-to-mean ratios of downwind odour intensity were computed from field odour intensity measurements and analysed against averaging time, downwind distance, and atmospheric stability class. The peak-to-mean ratio of field odour intensity increases with averaging time and downwind distance, and unstable atmospheric conditions.

The enhanced axial mixing which is caused by dispersion in oscillatory flows in some mass transfer devices may limit the reactor performance. This effect has provided the motivation for the present study in which oscillatory flow dispersion in a flat channel of large aspect ratio is investigated. The rate of spreading of a uniform slug of some passive tracer has been predicted using numerical and analytical techniques and the results have been verified experimentally. The numerical approach has used a finite difference time-marching method to obtain predictions for the channel concentrations. From the results, the dispersion coefficient (D) has been evaluated for Strouhal numbers of O.O1→0.2 and for mean Reynolds numbers of O.4→2OO at Schmidt numbers (Sc) O(1O³) . It has been concluded that under these conditions D varies as stroke squared. Unless the flow is not quasi-steady (i.e. if pulsatile Reynolds number α²<O(l)) D is only a weak function of frequency. These predictions for the dispersion coefficient have been in excellent agreement with those of Watson (256). It has also been concluded from the numerical study that the phase of the velocity sinusoid at the instant of injection has a critical effect upon the form of the concentration evolution. An approximate analytical technique has been developed in which weighted mean cross-channel concentrations are defined. The wall concentration is expressed approximately using a Fourier series. This procedure leads to ordinary differential equations for the axial moments. When the axial variance of mean concentration and the dispersion coefficient were computed in this way for quasi-steady flows good agreement was obtained with the numerical work. Simple opto-electronic gauges have been developed to measure mean cross-channel concentrations. The sensors have been used to obtain experimental data for the dispersion coefficient of a furrowed channel mass transfer device using slug stimulus techniques. Experimental investigations of dispersion in oscillatory flows in a flat channel using these gauges has produced values for D which are in agreement with the theoretical predictions for quasi-steady flows.

No description available.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of New South Wales, 2004. / Also available online.