The aim of this study was to develop a suitable monitoring protocol for mediated amperometric whole-cell biosensors for in situ assessment of heavy metals in soil. E. coli 8277, Pseudomonas 9773, Pseudomonas 9046 and Pseudomonas 8917 were screened as biosensor catalysts to select the sensitive biosensor configurations to heavy metals. A new protocol was developed for monitoring heavy metals in defined solution, soil pore water, and in situ in soil. This study also demonstrated the applications of mediated amperometric bacterial biosensors for in situ assessing the bioavailability and toxicity of heavy metals in freshly spiked soils or historically contaminated soils, and mixture toxicities of heavy metals. It was found that the biosensors incorporating selected bacterial strains were appropriately sensitive to copper, but less sensitive to Zn, Pb, and Hg, compared to Microtox assay. The advantage of the mediated amperometric bacterial biosensor system is its in situ application in soils. The present study demonstrated that soil pore water does not accurately reflect conditions of soil ecosystem, and that in situ bioassays are more reliable for determining the bioavailability and toxicity of heavy metals. This is the first reported use of disposable whole cell biosensors for in situ heavy metal bioavailability and toxicity assessment. The biosensor protocol developed here can be adapted to allow the incorporation of dfferent bacterial biocatalysts for applications in soil quality assessment, screening of sites for contamination ‘hot spots’, and the evaluation of soil degradation or rehabilitation from metal pollution. Mediated amperometric bacterial biosensors are not analyte specific, their response reflecting the metabolic impact of the combined chemical and physical properties of the environment to which they are exposed. In assessing the toxicity of soil samples from fields using these biosensors, it is vital to get appropriate control soil samples. The conditions of soil samples also need to be well defined. The sensitivity of the mediated amperometric whole-cell biosensors to heavy metals need to be further improved. Investigations are also required to determine how the natural conditions affect the application of the biosensor system in the field.

The purpose of this thesis is to compare policy instruments with respect to cost efficiency, income distribution effects, technological change and violation incentives. The policy instruments under study are quota, charge and permit market system. The analysis is applied to Gotland, an island in the Baltic where the content of nitrate in drinking water is high. As in many other agricultural districts, the source of pollution is farmers’ use of nitrogen. According to the results, a permit market performs best with respect to cost efficiency and income distribution effects. The empirical calculations show that a permit market system may amount to half the cost of the most expensive alternative. All three policy instruments are found to encourage technological change, although to different degrees. In most instances the incentives for technological adjustments are highest for the charge and permit market systems. The incentives to violate regulations may be the smallest under a permit market system. But they can also be higher and of the same magnitude as under a charge system. The main reason for this variation is that the occurrence of illegal use of nitrogen affects the marketclearing price of permits. This, in turn, may reduce the economic incentives to violate regulations of a permit market system. / Diss. Stockholm : Handelshögsk., 1989

Thesis (M. Arch.)--University of Hong Kong, 1994. / Includes special report study entitled: Insolation CAD modelling. Includes bibliographical references.

No description available.

No description available.

No description available.

Lic.-avh. (sammanfattning) Stockholm : Tekn. högsk., 2006. / Härtill 3 uppsatser.

Thesis (Ph. D.)--Stanford University, 1991. / "May 1991." Includes bibliographical references (p. 201-219).

Thesis (M.Arch.)--University of Hong Kong, 1994. / Includes special report study entitled : Insolation CAD modelling. Includes bibliographical references. Also available in print.

abstract: The release of organophosphorus compounds (OPs) and subsequent exposure to these compounds is of concern to humans and the environment. The goal of this work was to control the concentrations of gaseous OPs through interaction with sorbent oxides. Experimental and computational methods were employed to assess the interactions of dimethyl phosphite (DMHP), dimethyl methylphosphonate (DMMP), dimethyl ethylphosphonate (DMEP), diethyl ethylphosphonate (DEEP), and triethyl phosphate (TEP) with amorphous silica (a-silica), ã-alumina, and monoclinic zirconia (m-zirconia) for applications in air pollution control. Interactions of the selected OPs with a-silica were chosen as a baseline to determine the applicability of the computational predictions. Based on the a-silica results, computational methods were deemed valid for predicting the trends among materials with comparable interactions (e.g. -OH functionality of a-silica interacting with the phosphonyl O atoms of the OPs). Computational evaluations of the interactions with the OPs were extended to the oxide material, m-zirconia, and compared with the results for ã-alumina. It was hypothesized that m-zirconia had the potential to provide for the effective sorption of OPs in a manner superior to that of the a-silica and the ã-alumina surfaces due to the surface charges of the zirconium Lewis acid sites when coordinated in the oxidized form. Based on the computational study, the predicted heats of adsorption for the selected OPs onto m-zirconia were more favorable than those that were predicted for ã-alumina and a-silica. Experimental studies were carried out to confirm these computational results. M-zirconia nanoparticles were synthesized to determine if the materials could be utilized for the adsorption of the selected OPs. M-zirconia was shown to adsorb the OPs, and the heats of adsorption were stronger than those determined for commercial samples of a-silica. However, water interfered with the adsorption of the OPs onto m-zirconia, thus leading to heats of adsorption that were much weaker than those predicted computationally. Nevertheless, this work provides a first investigation of m-zirconia as a viable sorbent material for the ambient control of the selected gaseous OPs. Additionally, this work represents the first comparative study between computational predictions and experimental determination of thermodynamic properties for the interactions of the selected OPs and oxide surfaces. / Dissertation/Thesis / Ph.D. Chemical Engineering 2011