No description available.

No description available.

No description available.

No description available.

Field and greenhouse bioassay experiments were conducted to evaluate the effects of mesotrione soil residues on injury and yield of soybean, green bean, pea, cucumber, sugar beet and lettuce. There was a significant difference of mesotrione carryover between studies which can be explained by differences in soil pH and moisture. The conventional and the simulated field residue carryover studies successfully measured mesotrione persistence and rotational crop sensitivity. The simulated residue carryover study provided a more rigorous test of rotational crop sensitivity to mesotrione residues than the conventional residue carryover study, especially at higher doses for the more sensitive crops. The greenhouse bioassay was a simple and sensitive tool in detecting small amounts of herbicides present in the soil. Dose-response curves developed for sugar beet and green bean indicate similarities between results from the greenhouse and from the field mesotrione residue carryover study. Under similar environmental and soil conditions to those observed in these studies and using similar dose applications, sugar beet, green bean and cucumber injury and yield reductions are likely when these crops are grown in soils containing mesotrione residues.

The characteristics and applications of a novel design of a thin film photocontactor based on the principle of irradiating a 'water bell' with ultraviolet (UV) light a,e considered in this work. Measurements of UV doses received by the liquid films in single passes were made using both actinometric and bioassay-based methods. The chemical actinometer employed was potassium ferrioxalate (K,Fe(C,o.l,)) and the microorganisms used in the bioassay were Pseudomonas stutzeri (mRG) and a repair-deficient strain of Escherichia coli (NCIMB 11190). Good agreement was obtained between the doses measured using actinometry and the E. coli-based bioassay. At higher doses, good agreement was also obtained for the dose estimates made using actinometry and the Ps. stutzeri bioassay. In addition, a hydrodynamic water bell model, previously developed in the literature, was combined with a UV intensity model to predict UV doses with generally good results. Microbially contaminated metal working fluids were identified as a suitable medium for disinfection using the thin film contactor because they are not treatable using conventional UV contactors, and because the systems employed in industry vary widely in scale. Batches of contaminated emulsion ranging in volume from 200 to 1000 L were successfully disinfected. Representative members of the microbial population were isolated, and their changing status throughout treatment recorded. Against expectations, the population showed no capacity for the post-irradiation repair of UV-induced damage. A simplified disinfection model was established in order to model the treatment of batches of contaminated metal working fluids. Preliminary predictions made using a combination of experimental data for the population as a whole and that for individual species coupled with that generated using the hydrodynamic bell model, gave encouraging results.

Univ., Diss.--Regensburg, 1997.

Stuttgart, Univ., Diss., 2000.

Tierärztl. Hochsch., Diss., 2003--Hannover.

Tierärztl. Hochsch., Diss., 2003--Hannover.