In 1995, the Swedish government recommended the discontinuation of amalgam as restorative in paediatric dentistry. Because the mercury content in amalgam constitutes an environmental hazard, its use has declined. The use of resin composites is increasing, but the polymerisation shrinkage of the material is still undesirably high, and the handling of uncured resin can cause contact dermatitis. A new restorative material has recently been developed in Sweden as an alternative to amalgam and resin composite: a calcium aluminate cement (CAC). CAC has been marketed as a ceramic direct restorative for posterior restorations (class I, II) and for class V restorations. This thesis evaluates mechanical properties and clinical durability of the calcium aluminate cement when used for class II restorations. Hardness, in vitro wear, flexural strength, flexural modulus, and surface roughness were evaluated. A scanning electron replica method was used for evaluation of the interfacial adaptation to tooth structures in vivo. The durability was studied in a 2-year intra-individually clinical follow-up of class II restorations. Major results and conclusions from the studies are as follows: • The CAC was a relatively hard material, harder than resin-modified glass ionomer cement but within the range of resin composites. The CAC wore less than resin-modified glass ionomer cement but more than resin composite. • Flexural strength of CAC was in the same range as that of zinc phosphate cement and far below that of both resin composite and resin-modified glass ionomer cement. Flexural modulus of CAC was higher than both resin composite and resin-modified glass ionomer cement. The low flexural strength of CAC precludes its use in stress-bearing areas. • Surface roughness of CAC could be decreased by several polishing techniques. • For CAC restorations, interfacial adaptation was higher to dentin but lower to enamel compared with resin composite restorations. Fractures were found perpendicular to the boarders of all CAC restorations and may indicate expansion of the material. • After 2 years of clinical service, the class II CAC restorations showed an unacceptably high failure rate. Material fractures and tooth fractures were the main reasons for failure.

The understanding of surfaces of materials is of crucial importance to all of us. Considering nanocrystals (NCs), that have a large surface to bulk ratio, the surfaces become even more important. Therefore, it is important to understand the fundamental surface properties in order to use NCs efficiently in applications. In the work reported in this thesis ZnO NCs were studied. At MAX-lab in Lund, synchrotron radiation based Spectroscopic Photoemission and Low Energy Electron Microscopy (SPELEEM) and X-ray Photoelectron Spectroscopy (XPS) were used. At Karlstad University characterization was done using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), Scanning Tunnelling Microscopy (STM), Auger Electron Spectroscopy (AES), and XPS. The fundamental properties of ZnO surfaces were studied using distributions of ZnO NCs on SiO2/Si surfaces. The conditions for distribution of ZnO NCs were determined to be beneficial when using ethanol as the solvent for ultrasonically treated dispersions. Annealing at 650 °C in UHV cleaned the surfaces of the ZnO NCs enough for sharp LEEM imaging and chemical characterization while no sign of de-composition was found. A flat energy band structure for the ZnO/SiO2/Si system was proposed after 650 °C. Increasing the annealing temperature to 700 °C causes a de-composition of the ZnO that induce a downward band bending on the surfaces of ZnO NCs. Flat ZnO NCs with predominantly polar surfaces were grown using a rapid microwave assisted process. Tuning the chemistry in the growth solution the growth was restricted to only plate-shaped crystals, i.e. a very uniform growth. The surfaces of the NCs were characterized using AFM, revealing a triangular reconstruction of the ZnO(0001) surface not seen without surface treatment at ambient conditions before. Following cycles of sputtering and annealing in UHV, we observe by STM a surface reconstruction interpreted as 2x2 with 1/4 missing Zn atoms. / Baksidestext The understanding of the surfaces of materials is of crucial importance to all of us. Considering nanocrystals (NCs), that have a large surface to bulk ratio, the surfaces become even more important. In the work in this thesis ZnO NCs were studied. The fundamental properties of ZnO surfaces were studied using distributions of ZnO NCs on SiO2/Si surfaces. Annealing at 650 °C in UHV cleaned the surfaces of the ZnO NCs enough for sharp LEEM imaging and chemical characterization while no sign of de-composition was found. A flat energy band structure for the ZnO/SiO2/Si system was proposed after 650 °C. Increasing the annealing temperature to 700 °C causes a de-composition of the ZnO that induce a downward band bending on the surfaces of ZnO NCs. Flat ZnO NCs with predominantly polar surfaces were grown using a microwave assisted process. Tuning the chemistry in the growth solution the growth was restricted to only plate-shaped crystals, i.e. a very uniform growth. The surfaces of the NCs were characterized using AFM, revealing a triangular reconstruction of the ZnO(0001) surface not seen without surface treatment at ambient conditions before. Following cycles of sputtering and annealing in UHV, we observe by STM a surface reconstruction interpreted as 2x2 with 1/4 missing Zn atoms.

Part I: Various image reconstruction algorithms used for subsurface targets are reviewed. It is shown how some approximate wavefield inversion techniques: Stripmap Synthetic Aperture Radar (SAR), Kirchhoff Migration (KM) and Frequency-Wavenumber (FK) migration are developed from various models for wavefield scattering. The similarities of these techniques are delineated both from a theoretical and practical perspective and it is shown that Stripmap SAR is, computationally, almost identical to FK migration. A plane wave interpretation of both Stripmap SAR and FK migration is used to show why they are so similar. The electromagnetic assumptions made in the image reconstruction algorithms are highlighted. In addition, it is shown that, theoretically, FK and KM are identical. Image reconstruction results for KM, Stripmap SAR and FK are shown for both synthetic and experimental Ground Penetrating Radar (GPR) data. Subjectively the reconstructed images show little difference, but computationally, Stripmap SAR (and therefore, FK migration) are much more efficient. Part II: A preliminary investigation into the use of the Singularity Expansion Method (SEM) for use in identifying landmines is completed using a Finite-Difference Time-Domain code to simulate a simplified GPR system. The Total Least Squares Matrix Pencil Method (TLS-MPM) is used to determine the complex poles from an arbitrary late-time signal. Both dielectric and metallic targets buried in lossless and lossy half-spaces are considered. Complex poles (resonances) of targets change significantly when the objects are buried in an external medium, and perturbation formulae for Perfect Electric Conductor (PEC) and dielectric targets are highlighted and used. These perturbation formulae are developed for homogenous surrounding media, and their utilization for the half-space (layered medium) GPR problem causes inaccuracies in their predictions. The results show that the decay rate (real part) of the complex poles is not suitable for identification in this problem, but that with further research, the resonant frequency (imaginary part) of the complex poles shows promise as an identification feature. / February 2005

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants known for their photoinduced toxicity. There are two mechanisms through which this may occur: photosensitization and photomodification. Photosensitization generally leads to the production of singlet oxygen, a reactive oxygen species (ROS), which is highly damaging to biological molecules. Photomodification of PAHs, usually via oxygenation, results in the formation of new compounds (oxyPAHs), and can occur under environmentally relevant levels of actinic radiation. <br /><br /> PAHs and oxyPAHs readily adsorb to the organic phase of particulate matter in the environment such as sediments. It is logical to conclude that sediment transport will also facilitate the transport of these contaminants, and it has been shown that in the course of transport, degradative processes evoke a change in the profile of the PAHs present. Sediment samples taken along a transect from Hamilton Harbour were fractionated, and analyzed using a 2D HPLC method. All sediments contained intact and modified PAHs, although a marked change was noted in the profile of compounds present in the samples, which differ in distance from shore. Fractions of sediment extract were tested for toxicity using a bacterial respiration assay. Toxicity was observed in fractions containing modified PAHs, and was similar to that of intact PAH-containing fractions. <br /><br /> Subsequently, the toxicities of 16 intact PAHs were assessed to <i>Daphnia magna</i> under two ultraviolet radiation (UV) conditions. The toxicity of intact PAHs generally increased in the presence of full spectrum simulated solar radiation (SSR), relative to visible light plus UVA only. To expand the existing data on the effects of PAH photoproducts to animals, fourteen oxyPAHs were also assayed with <i>D. magna</i>, most of which were highly toxic without further photomodification. The data presented highlight the effects of UV radiation on mediating PAH toxicity. The importance of the role of photomodification is also stressed, as several oxyPAHs were highly toxic to <i>D. magna</i>, a key bioindicator species in aquatic ecosystems. <br /><br /> A QSAR model previously developed for <i>Lemna gibba</i> showed that a photosensitization factor (PSF) and a photomodification factor (PMF) could be combined to describe toxicity. To determine whether it was predictive for <i>D. magna</i>, toxicity was assessed as both EC50 and ET50. As with <i>L. gibba</i> and <i>Vibrio fischeri</i>, neither the PSF nor the PMF alone correlated to D. magna toxicity. However, a PSF modified for <i>D. magna</i> did in fact exhibit correlation with toxicity, which was further improved when summed with a modified PMF. The greatest correlation was observed with EC50 toxicity data. This research provides further evidence that models that include factors for photosensitization and photomodification will likely be applicable across a broad range of species. To gain further knowledge of the roles that the variables contributing to the photosensitization and photomodification, a structural equation model was constructed based on the <i>D. magna</i> QSAR. This model accounted for a high amount of variance in six sets of toxicity data, as well as insight into the mechanisms of phototoxicity affecting different aquatic organisms.

Early maturity is an important objective for breeding flax adapted to the Western Canada. Crop canopy traits influence seed yield; however, studying its effects is challenging due to the complexity and limited knowledge of the genetics of this trait. The objectives of this research are : i) to characterize flax accessions from the Canadian gene bank collection for early flowering, maturity and canopy traits; ii) to identify SSR markers associated with plant branching and leaf area index (LAI); iii) to use Structural Equation Modeling (SEM) to identify canopy variables with significant effects on yield. The flax core collection, consisting of approximately 381 accessions, was grown at the Kernen Crop Research Farm in 2010 and 2011. Additionally, 17 early and 17 late flowering accessions from the flax core collection were screened and their phenotypic responses in both growth chamber and field environments were measured. A large amount of phenotypic diversity was observed in long day and short day environments in these experiments. Some accessions appeared to be more photosensitive, while others were photoperiod insensitive. The genetic control of canopy traits such as LAI and plant branching were studied using association mapping. Genotyping of the core collection was conducted using 375 SSR markers. Population structure analysis assigned the 381 flax accessions in the core collection into four distinct groups. Model comparison revealed that the mixed linear model reduced spurious marker trait associations. A total of 26 markers were identified to be significantly associated with plant branching and LAI. The simultaneous examination of crop phenology and canopy traits to seed yield was performed using SEM analysis. The results indicated greater plant stand resulted in higher irradiance absorption and which resulted in greater seed yield. Days to flowering had a significant negative effect on seed yield and growing degree days to maturity had a significant effect on seed yield. Plant branching and plant height had a positive non-linear effect on seed yield. This study has provided several insights into molecular approaches and statistical methods to improve flax breeding.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants known for their photoinduced toxicity. There are two mechanisms through which this may occur: photosensitization and photomodification. Photosensitization generally leads to the production of singlet oxygen, a reactive oxygen species (ROS), which is highly damaging to biological molecules. Photomodification of PAHs, usually via oxygenation, results in the formation of new compounds (oxyPAHs), and can occur under environmentally relevant levels of actinic radiation. <br /><br /> PAHs and oxyPAHs readily adsorb to the organic phase of particulate matter in the environment such as sediments. It is logical to conclude that sediment transport will also facilitate the transport of these contaminants, and it has been shown that in the course of transport, degradative processes evoke a change in the profile of the PAHs present. Sediment samples taken along a transect from Hamilton Harbour were fractionated, and analyzed using a 2D HPLC method. All sediments contained intact and modified PAHs, although a marked change was noted in the profile of compounds present in the samples, which differ in distance from shore. Fractions of sediment extract were tested for toxicity using a bacterial respiration assay. Toxicity was observed in fractions containing modified PAHs, and was similar to that of intact PAH-containing fractions. <br /><br /> Subsequently, the toxicities of 16 intact PAHs were assessed to <i>Daphnia magna</i> under two ultraviolet radiation (UV) conditions. The toxicity of intact PAHs generally increased in the presence of full spectrum simulated solar radiation (SSR), relative to visible light plus UVA only. To expand the existing data on the effects of PAH photoproducts to animals, fourteen oxyPAHs were also assayed with <i>D. magna</i>, most of which were highly toxic without further photomodification. The data presented highlight the effects of UV radiation on mediating PAH toxicity. The importance of the role of photomodification is also stressed, as several oxyPAHs were highly toxic to <i>D. magna</i>, a key bioindicator species in aquatic ecosystems. <br /><br /> A QSAR model previously developed for <i>Lemna gibba</i> showed that a photosensitization factor (PSF) and a photomodification factor (PMF) could be combined to describe toxicity. To determine whether it was predictive for <i>D. magna</i>, toxicity was assessed as both EC50 and ET50. As with <i>L. gibba</i> and <i>Vibrio fischeri</i>, neither the PSF nor the PMF alone correlated to D. magna toxicity. However, a PSF modified for <i>D. magna</i> did in fact exhibit correlation with toxicity, which was further improved when summed with a modified PMF. The greatest correlation was observed with EC50 toxicity data. This research provides further evidence that models that include factors for photosensitization and photomodification will likely be applicable across a broad range of species. To gain further knowledge of the roles that the variables contributing to the photosensitization and photomodification, a structural equation model was constructed based on the <i>D. magna</i> QSAR. This model accounted for a high amount of variance in six sets of toxicity data, as well as insight into the mechanisms of phototoxicity affecting different aquatic organisms.

­^¤åºK­n¬°none

The perceptions of organizational politics and organizational citizenship behavior are neither regulated nor indentified in any organization. But, they are exactly existed in organization. This study is based on the revise model of Perceptions of Organizational Politics (POP) proposed by Ferris et al. (2002). We investigate the relationship between the perceptions of organizational politics and the organizational citizenship behavior. Furthermore, we investigate the indirect effect between the perceptions of organizational politics and the subordinates of organizational citizenship behavior. This study used the scales of 35 items collected by Dr. Chin-ming Ho and the other members of the last research team of POP in 2008. The research is based on the revision model of POP and questionnaire survey. The sample consisted of 1,890 employee selected from 40 organizations covering 9 industrial sectors in Taiwan. The method, path analysis with latent variables of the structural equation modeling (SEM) is used to measure the relationship among the constructs. The major result of this study is as following: 1. The perceptions of organizational politics have negative effect on the organizational citizenship behavior. 2. The perceptions of organizational politics have negative effect on the altruism toward colleagues 3. The perceptions of organizational politics have negative effect on the conscientiousness 4. The perceptions of organizational politics have negative effect on the identification with company 5. The perceptions of organizational politics have negative effect on the interpersonal harmony 6. The perceptions of organizational politics have negative effect on the protecting company resources

Spore morphology of Polypodiaceae and Grammitidaceae from Taiwan were studied with light microscope and scanning electron microscope. Totally 18 genera and 62 species were observed. Polypodiaceae spores are ellipsoidal and monolete except Loxogramme grammitoides; with spore ornamentation tuberculate, verrucate, echinate, globule, rugate, undulate, foveolate and/or vermiculate. Grammitidaceae spores are global, trilete with spore ornamentation granulate, tuberculate and/or globules. The spore surface ornamentation can be used as taxonomic characters in Polypodiaceae and Grammitidaceae at familial, genera and species levels. Based on spore characters, Polypodiaceae and Grammitidaceae can be differentiated, Loxogrammeae and Drynariaeae are not separable from the rest of Polypodiaceae, and the current classification system of Lepisorieae and Microsoreae are not .internal consistent.

When the generation of experience economy coming, customers are becoming care if the products or services which are company provide is what they need. Customers want what let them feel dizzy, what is able to touch their mind, stimulate their think, what is related to them, and also the product or marketing activities is connected to their life style(Pine II & Gilmore, 1999¡FSchmitt, 1999), it means that experience economy is becoming a trend of product consuming. Therefore, this study attempt to quote the Comprehensive model raised by Cronin, Brady and Hult (2000) and the Cognitive Model raised by Oliver(1980) as basic research frames, to prove the following goals of this study. After consumers which have been shopping in IKEA cognize the experiential value, whether their cognition will affect consumers¡¦ satisfaction or not. In addition, consumers will have the brand loyalty to IKEA. According to the result, it provides some suggestions to their experiential marketing. According to the results, consumers¡¦ experiential value will affect consumer satisfaction positively. When consumers¡¦ satisfaction becomes higher, and their brand loyalty becomes higher. In addition, when consumers¡¦ experiential value of playfulness becomes higher, and their brand loyalty becomes higher. However, some kinds of experiential value including aesthetics, service excellence and customer ROI have to let consumer have consumer satisfaction, then it can make consumers have loyalty to the brand.