This bachelor thesis aims to estimate Sweden’s export potential towards South-Korea since initial data indicates that Sweden has from 1997 up until 2005 been exporting less to South-Korea when compared to, in general, OECD. Furthermore, South-Korea seems to be a low prioritized market for Swedish firms in the East-Asian region. As many before us, we have used a basic gravity model, including GDP and distance in kilometer has been used as explanatory variables for the observed trade value. The dummy variable land-locked, to estimate trade potential for 15 commodity groups. Sweden was set to be the exporting country, South-Korea the importing country together with all the other OECD members, which were used as points of reference. The outcome of the gravity regression shows that distance and the dummy variable landlocked (if a country does not have access to open water) have a very strong relationship to the observed export data. However, GDP was proven to have a very weak relationship to the observed export data thus making the estimation process of trade potential for all, except one, commodity group biased. The gravity model has been widely criticized for inflating export potential due to misspecification a problem that we experienced when running our regression. Thus, from this study no strong conclusions can be drawn concerning the trade potential from Sweden to South-Korea.

The self-potential method responds to the electrokinetic phenomenon of streaming potential and has been applied in hydrogeologic and engineering investigations to aid in the evaluation of subsurface hydraulic conditions. Of specific interest is the application of the method to embankment dam seepage monitoring and detection. This demands a quantitative interpretation of seepage conditions from the geophysical data. To enable the study of variably saturated flow problems of complicated geometry, a three-dimensional finite volume algorithm is developed to evaluate the self-potential distribution resulting from subsurface fluid flow. The algorithm explicitly calculates the distribution of streaming current sources and solves for the self-potential given a model of hydraulic head and prescribed distributions of the streaming current cross-coupling conductivity and electrical resistivity. A new laboratory apparatus is developed to measure the streaming potential coupling coefficient and resistivity in unconsolidated soil samples. Measuring both of these parameters on the same sample under the same conditions enables us to properly characterize the streaming current cross-coupling conductivity coefficient. I present the results of a laboratory investigation to study the influence of soil and fluid parameters on the cross-coupling coefficient, and characterize this property for representative well-graded embankment soils. The streaming potential signals associated with preferential seepage through the core of a synthetic embankment dam model are studied using the forward modelling algorithm and measured electrical properties to assess the sensitivity of the self-potential method in detecting internal erosion. Maximum self-potential anomalies are shown to be linked to large localized hydraulic gradients that develop in response to piping, prior to any detectable increase in seepage flow through the dam. A linear inversion algorithm is developed to evaluate the three-dimensional distribution of hydraulic head from self-potential data, given a known distribution of the cross-coupling coefficient and electrical resistivity. The inverse problem is solved by minimizing an objective function, which consists of a data misfit that accounts for measurement error and a model objective function that incorporates a priori information. The algorithm is suitable for saturated flow problems or where the position of the phreatic surface is known.

An assessment procedure to measure the learning potential of mildly and moderately mentally handicapped adults was investigated in this study. The procedure was developed to overcome the limitations of previously established learning potential assessment procedures by meeting the specific orientation necessary when assessing the mentally handicapped, by avoiding practice and mechanical memory effects, and by requiring the subjects to show the ability to retain and apply new cognitive skills. Thirty institutionalized mentally handicapped adults were matched on IG and then randomly assigned to an assessment or control group. For the assessment group the intervention procedure involved the Coloured Progressive Matrices test as a pretest measure, in four treatment sessions each two to three days apart, and as a posttest measure. Verbal and/or figural aids were provided when an incorrect response was given on a test item during the treatment sessions. The control group was provided the same number of administrations of the test but without the treatment intervention. Significant differences were found between the pre and post test performance levels of the assessment group. The control group showed no significant gains. The learning potential assessment procedure used in this study provided a measure of the learning potential of mentally handicapped institutionalized adults.The results indicate that the mentally handicapped can perform at much higher levels than those assessed by standardly used intellectual measures. Implications are that through the use of this approach a clearer discrimination of intellectual ability within the broad classifications of the mentally handicappped can be gained. Such information could be used to aid in the selection of peers, developmental programming decisions, and provide prescriptive information about the most efficacious modes of learning for an individual.

Graduation date: 1991

Graduation date: 1994

Classically 13% Cr is required for stable passivity of steel in acidic and neutral solutions. Some authors (Mansfeld, Fujimoto) have published potential cycling procedures that generate thick Cr-rich films. Fujimoto cycles right to the transpassivity potential and back in H2SO4 solution. Our idea is to work close to the reactivation potential where the passive film (Fe2O3) is reductively dissolved to Fe2+. While using an equimolar acetate buffer (pH 4.7), we have obtained new insights into the reactivation process. It is under a kind of thermodynamic control, in that the film cannot be reduced, and the metal cannot be dissolved, faster than would exceed the equilibrium concentration of Fe2+ at the electrode surface. Reductive dissolution leads to gel-like Cr-rich film, but Fe dissolution occurs through it, if formed in a single step. However alternating formation and reductive dissolution of a Fe-rich film assist the formation of a more robust Cr-rich film

Using the short-lived radiotracer 13N, we examined the hypothesis that toxic, futile ammonia/ammonium (NH3/NH4+) fluxes at high external concentrations are mediated by ammonia-transporting aquaporins in roots of intact barley (Hordeum vulgare L.) plants. Effects of the aquaporin inhibitors zinc, copper, mercury, gold, silver, hydrogen peroxide, propionic acid, and nitrogen gas supported this hypothesis. Further tests with these inhibitors showed that changes in plant water potential and water content could be linked to NH3/NH4+ fluxes. An increase in external pH, causing an increase of NH3 in the nutrient solution, resulted in large increases of 13N influx, which can only be explained in energetic terms if the transported solute is neutrally charged. Taken together, the evidence here strongly supports the proposed hypothesis.

This thesis describes the synthesis and assembly of metal and semiconductor nanoparticles (NPs). The two research topics include i) hetero-assembly of metal and semiconductor NPs, ii) effect of ionic strength on homo-assembly of gold nanorods (GNRs). First, we present hetero-assembly of GNRs and semiconductor quantum dots (QDs) in a chain using biotin-streptavidin interaction. We synthesized alloyed CdTeSe QDs and modified them with mercaptoundecanoic acid to render them water-soluble and to attach streptavidin. We synthesized GNRs by a seed-mediated method and selectively modified the ends with biotin. Hetero-assembly of QDs and GNRs depended on the size, ligands, and ratio of QDs and GNRs. Second, we controlled the rate of homo-assembly of GNRs by varying the ionic strength of the DMF/water solution. The solubility of polystyrene on the ends of GNRs depended on the ionic strength of the solution, which correlated with the rate of assembly of GNRs into chains.

Using the short-lived radiotracer 13N, we examined the hypothesis that toxic, futile ammonia/ammonium (NH3/NH4+) fluxes at high external concentrations are mediated by ammonia-transporting aquaporins in roots of intact barley (Hordeum vulgare L.) plants. Effects of the aquaporin inhibitors zinc, copper, mercury, gold, silver, hydrogen peroxide, propionic acid, and nitrogen gas supported this hypothesis. Further tests with these inhibitors showed that changes in plant water potential and water content could be linked to NH3/NH4+ fluxes. An increase in external pH, causing an increase of NH3 in the nutrient solution, resulted in large increases of 13N influx, which can only be explained in energetic terms if the transported solute is neutrally charged. Taken together, the evidence here strongly supports the proposed hypothesis.

This thesis describes the synthesis and assembly of metal and semiconductor nanoparticles (NPs). The two research topics include i) hetero-assembly of metal and semiconductor NPs, ii) effect of ionic strength on homo-assembly of gold nanorods (GNRs). First, we present hetero-assembly of GNRs and semiconductor quantum dots (QDs) in a chain using biotin-streptavidin interaction. We synthesized alloyed CdTeSe QDs and modified them with mercaptoundecanoic acid to render them water-soluble and to attach streptavidin. We synthesized GNRs by a seed-mediated method and selectively modified the ends with biotin. Hetero-assembly of QDs and GNRs depended on the size, ligands, and ratio of QDs and GNRs. Second, we controlled the rate of homo-assembly of GNRs by varying the ionic strength of the DMF/water solution. The solubility of polystyrene on the ends of GNRs depended on the ionic strength of the solution, which correlated with the rate of assembly of GNRs into chains.