The need for protection of eyes and electro-optic sensors from powerful lasers has increased the need for new and better optical power limiting (OPL) materials that can protect against laser light. In this study the synthesis and characterization of dendron-coated OPL chromophores (porphyrins, thiophenes, and platinum(II) acetylides) are discussed. The work has been divided into two different main parts. In the first part it was investigated if dendrons could be attached to these chromophore molecules. The dendrons were attached using the versatile chemistry of the acetonide protected anhydride of 2,2-bis(methylol)propionic acid (bis-MPA). The resulting dendrimers were characterized with NMR, SEC and MALDI-TOF to verify that well-defined molecules were obtained. Well-defined virtually monodisperse dendron-coated chromophores up to the fourth generation were synthesized for the three different chromophores. For the porphyrins the fifth generation were also synthesized but molecular weight measurements showed that they were not perfect. In the second part the performance of the dendron-coated materials for protection against lasers was analyzed. Other spectroscopic studies such as absorption, emission, and lifetime measurements were also performed to understand the influence of the dendritic coating on the properties of the materials. The dendritic coating had little effect on the free-base porphyrins and the thiophenes and there were no differences in the OPL for different generations. The zinc-cored porphyrins showed significantly better OPL properties but their linear transmissions were low. The zinc porphyrins absorption and emission spectra were affected by the dendron coating and the OPL properties were deteriorated with increasing generation. The effects were most prominent for the largest dendrimers and it is believed that they change the conformation and vibrational substructure of the porphyrin. The platinum(II) acetylides were also influenced by the dendron coating. They showed improved OPL properties with increasing generation. This improvement is attributed to the longer lifetimes of the excited states for the larger dendrons, which increases the excited state absorption. Initial solid-state materials in a poly(methyl methacrylate) (PMMA) were made showing that the OPL effects are retained in the solid state but that the linear transmission and damage threshold are reduced.

The shoot apical meristem (SAM) is the structure that shapes the aerial architecture of the plant, by producing lateral organs throughout development. In the model plant Arabidopsis thaliana, the SAM is always identifiable as a characteristic dome, whether it is found in the centre of a rosette of leaves or at the tip of an inflorescence. When senescence occurs and organogenesis ceases, the now inactive SAM still retains its characteristic appearance and it is never consumed into a terminal structure, such as a flower. Mutant plants that undergo termination represent a valuable tool to understand how the SAM structure and function are maintained during plant life. The aim of this work was to investigate the dynamics of meristem development through morphological and genetic studies of three Arabidopsis mutants that exhibit distinct modes of SAM termination: distorted architecture 1 (dar1), adenosine kinase 1 (adk1) and terminal flower 2 (tfl2). The dar1 mutation is characterised by a severely distorted cellular architecture within the SAM. We propose that dar1 affects the pattern of cell differentiation and/or cell proliferation within the SAM apical dome, resulting in termination by meristem consumption. Instead, the adk1 mutation affects the organogenic potential of the SAM, without altering its structure. The adk1 mutant has increased levels of cytokinins and, as a consequence of this, cell division is enhanced and cell differentiation is prevented in the apex, causing termination by meristem arrest. Finally, tfl2 is mutated in the conserved chromatin remodelling factor HP1, a transcriptional repressor with multiple roles during plant development. The tfl2 SAM terminates by conversion into a floral structure, due to de-repression of floral identity genes. Interestingly, tfl2 mutants also show an altered response to light, an indication that TFL2 might act as a repressor also in the context of light signalling.

<p>The need for protection of eyes and electro-optic sensors from powerful lasers has increased the need for new and better optical power limiting (OPL) materials that can protect against laser light. In this study the synthesis and characterization of dendron-coated OPL chromophores (porphyrins, thiophenes, and platinum(II) acetylides) are discussed. The work has been divided into two different main parts. </p><p>In the first part it was investigated if dendrons could be attached to these chromophore molecules. The dendrons were attached using the versatile chemistry of the acetonide protected anhydride of 2,2-bis(methylol)propionic acid (bis-MPA). The resulting dendrimers were characterized with NMR, SEC and MALDI-TOF to verify that well-defined molecules were obtained. </p><p>Well-defined virtually monodisperse dendron-coated chromophores up to the fourth generation were synthesized for the three different chromophores. For the porphyrins the fifth generation were also synthesized but molecular weight measurements showed that they were not perfect.</p><p>In the second part the performance of the dendron-coated materials for protection against lasers was analyzed. Other spectroscopic studies such as absorption, emission, and lifetime measurements were also performed to understand the influence of the dendritic coating on the properties of the materials. </p><p>The dendritic coating had little effect on the free-base porphyrins and the thiophenes and there were no differences in the OPL for different generations. The zinc-cored porphyrins showed significantly better OPL properties but their linear transmissions were low. The zinc porphyrins absorption and emission spectra were affected by the dendron coating and the OPL properties were deteriorated with increasing generation. The effects were most prominent for the largest dendrimers and it is believed that they change the conformation and vibrational substructure of the porphyrin. The platinum(II) acetylides were also influenced by the dendron coating. They showed improved OPL properties with increasing generation. This improvement is attributed to the longer lifetimes of the excited states for the larger dendrons, which increases the excited state absorption. </p><p>Initial solid-state materials in a poly(methyl methacrylate) (PMMA) were made showing that the OPL effects are retained in the solid state but that the linear transmission and damage threshold are reduced.</p>

<p>Det här arbetet syftar till att undersöka om och hur födoberikning kan stimulera vitörade silkesapor att utföra högre frekvenser av naturliga beteenden samt att se hur aktiva aporna är och om de frivilligt visar sig för publik på djurparken. Födoberikningen gick ut på att erbjuda aporna mat på ett mer naturligt sätt istället för att enbart ge dem maten i matskålar. Dessutom syftar arbetet till att erbjuda aporna en näringsmässigt korrekt sammansatt kost. Studien utfördes på två grupper av vitörade silkesapor på Parken Zoo i Eskilstuna under perioden juni till september år 2004. Undersökningen delades upp i tre perioder, under period 1 observerades aporna utan att någon födoberikning genomfördes. Under period 2 introducerades födoberikningen stegvis samtidigt som kostens sammansättning ändrades. Under period 3 var all födoberikning införd och kosten som erbjöds var näringsmässigt korrekt. Vår studie visar att frekvenserna av naturliga beteenden ökade vid födoberikning, det vill säga ätbeteende minskade, födosöksbeteende ökade och aggressiva/revir beteenden minskade. Socialt/övrigt beteende och förflyttning skilde sig åt mellan de två grupperna. Aporna blev mer aktiva och var mer synliga för publik under period 3. Vår matstudie visar att det är viktigt att utvärdera apornas kostintag på djurpark eftersom risken är stor att de inte erbjuds och äter rätt proportioner av olika näringsämnen.</p> / <p>The aim of this study is to examine whether and how food enrichment can stimulate the common marmoset to more frequently display natural behaviour patterns; also to see how active the monkeys are and if they voluntarily show themselves to the public in the zoo. The food enrichment meant offering food to the monkeys in a way more natural than simply providing it in bowls. In addition the aim is to provide a nutritionally balanced diet. The study was conducted on two groups of common marmosets in Parken Zoo in Eskilstuna from June 2004 to September 2004. The study was split into three periods. During period 1 the monkeys were observed without food enrichment. During period 2 food enrichment was introduced gradually while the diet changed. During period 3 all food enrichment was provided and the diet offered was nutritionally correct. Our study shows that natural behaviour became more frequent with food enrichment, that is, eating behaviour decreased, foraging behaviour increased and aggressive/territorial behaviour decreased. Social/other behaviour and motion differed between the two groups. The monkeys became more active and were more often visible to the public during period 3. Our feeding study shows the importance of evaluating the nutritional intake of the monkeys in a zoo, because of the risk that they are not offered or are not eating the right proportions of nutrients.</p>

<p>The work presented in this thesis describes the use of polystyrene nanoparticles as model surfaces for bioanalytical work. Nanoparticles constitute convenient platforms for the attachment of bioactive agents, and receptor coated particles offer high local concentration of binding sites for specific ligands with minimal steric hindrance. However, it is not only the amount of bound protein that matters, the proteins must also be immobilized at the surface in such ways that they fully retain their activity, while at the same time protecting the surface from unspecific uptake of undesired components. The present work relates to the controlled immobilization of multiple types of active biomolecules onto nanoparticle surfaces to make them multifunctional. The surface expansion offered by the nanoparticles, in combination with the closeness between the reactants co-immobilized on the same particle, enables coupled reactions to be carried at a higher rate than otherwise possible. Thus, particle-decorated surfaces of this kind are highly suitable for miniaturized bioanalytical systems. Sensitive microarray systems are under development, including lectin-coated nanoparticles for glycoprotein mapping and a diagnostic device for Point-of-Care testing with a nanoparticle-based detection system.</p><p>The full evaluation of protein attachment to nanoparticles requires precise analytical techniques for particle characterization, both in bare and coated form. The mass-sensitive SdFFF technique occupies a prominent position for particle characterization, as it offers both accurate determination of particle size and a quantification of adsorbed layers on small particles, whether of synthetic or biopolymeric nature. Here, this analytical technique is developed to precisely characterize nanoparticles that are sequentially coated with different layers, each rendering the particles a specific functionality. The thesis demonstrates how precise mass uptakes can be determined for each specific layer, and how control over the exact surface composition of the modified particles can be established for optimization of biological activity.</p>

The work presented in this thesis describes the use of polystyrene nanoparticles as model surfaces for bioanalytical work. Nanoparticles constitute convenient platforms for the attachment of bioactive agents, and receptor coated particles offer high local concentration of binding sites for specific ligands with minimal steric hindrance. However, it is not only the amount of bound protein that matters, the proteins must also be immobilized at the surface in such ways that they fully retain their activity, while at the same time protecting the surface from unspecific uptake of undesired components. The present work relates to the controlled immobilization of multiple types of active biomolecules onto nanoparticle surfaces to make them multifunctional. The surface expansion offered by the nanoparticles, in combination with the closeness between the reactants co-immobilized on the same particle, enables coupled reactions to be carried at a higher rate than otherwise possible. Thus, particle-decorated surfaces of this kind are highly suitable for miniaturized bioanalytical systems. Sensitive microarray systems are under development, including lectin-coated nanoparticles for glycoprotein mapping and a diagnostic device for Point-of-Care testing with a nanoparticle-based detection system. The full evaluation of protein attachment to nanoparticles requires precise analytical techniques for particle characterization, both in bare and coated form. The mass-sensitive SdFFF technique occupies a prominent position for particle characterization, as it offers both accurate determination of particle size and a quantification of adsorbed layers on small particles, whether of synthetic or biopolymeric nature. Here, this analytical technique is developed to precisely characterize nanoparticles that are sequentially coated with different layers, each rendering the particles a specific functionality. The thesis demonstrates how precise mass uptakes can be determined for each specific layer, and how control over the exact surface composition of the modified particles can be established for optimization of biological activity.

Det här arbetet syftar till att undersöka om och hur födoberikning kan stimulera vitörade silkesapor att utföra högre frekvenser av naturliga beteenden samt att se hur aktiva aporna är och om de frivilligt visar sig för publik på djurparken. Födoberikningen gick ut på att erbjuda aporna mat på ett mer naturligt sätt istället för att enbart ge dem maten i matskålar. Dessutom syftar arbetet till att erbjuda aporna en näringsmässigt korrekt sammansatt kost. Studien utfördes på två grupper av vitörade silkesapor på Parken Zoo i Eskilstuna under perioden juni till september år 2004. Undersökningen delades upp i tre perioder, under period 1 observerades aporna utan att någon födoberikning genomfördes. Under period 2 introducerades födoberikningen stegvis samtidigt som kostens sammansättning ändrades. Under period 3 var all födoberikning införd och kosten som erbjöds var näringsmässigt korrekt. Vår studie visar att frekvenserna av naturliga beteenden ökade vid födoberikning, det vill säga ätbeteende minskade, födosöksbeteende ökade och aggressiva/revir beteenden minskade. Socialt/övrigt beteende och förflyttning skilde sig åt mellan de två grupperna. Aporna blev mer aktiva och var mer synliga för publik under period 3. Vår matstudie visar att det är viktigt att utvärdera apornas kostintag på djurpark eftersom risken är stor att de inte erbjuds och äter rätt proportioner av olika näringsämnen. / The aim of this study is to examine whether and how food enrichment can stimulate the common marmoset to more frequently display natural behaviour patterns; also to see how active the monkeys are and if they voluntarily show themselves to the public in the zoo. The food enrichment meant offering food to the monkeys in a way more natural than simply providing it in bowls. In addition the aim is to provide a nutritionally balanced diet. The study was conducted on two groups of common marmosets in Parken Zoo in Eskilstuna from June 2004 to September 2004. The study was split into three periods. During period 1 the monkeys were observed without food enrichment. During period 2 food enrichment was introduced gradually while the diet changed. During period 3 all food enrichment was provided and the diet offered was nutritionally correct. Our study shows that natural behaviour became more frequent with food enrichment, that is, eating behaviour decreased, foraging behaviour increased and aggressive/territorial behaviour decreased. Social/other behaviour and motion differed between the two groups. The monkeys became more active and were more often visible to the public during period 3. Our feeding study shows the importance of evaluating the nutritional intake of the monkeys in a zoo, because of the risk that they are not offered or are not eating the right proportions of nutrients.

<p>The continuous trend in gas turbine design towards lighter, more powerful and more reliable engines on one side and use of alternative fuels on the other side renders flutter problems as one of the paramount challenges in engine design. Flutter denotes a self-excited and self-sustained aeroelastic instability phenomenon that can lead to material fatigue and eventually damage of structure in a short period of time unless properly damped. The design for flutter safety involves the prediction of unsteady aerodynamics as well as structural dynamics that is mostly based on in-house developed numerical tools. While high confidence has been gained on the structural side unanticipated flutter occurrences during engine design, testing and operation evidence a need for enhanced validation of aerodynamic models despite the degree of sophistication attained. The continuous development of these models can only be based on the deepened understanding of underlying physical mechanisms from test data.</p><p>As a matter of fact most flutter test cases treat the turbomachine flow in two-dimensional manner indicating that the problem is solved as plane representation at a certain radius rather than representing the complex annular geometry of a real engine. Such considerations do consequently not capture effects that are due to variations in the third dimension, i.e. in radial direction. In this light the present thesis has been formulated to study three-dimensional effects during flutter in the annular environment of a low-pressure turbine blade row and to describe the importance on prediction of flutter stability. The work has been conceived as compound experimental and computational work employing a new annular sector cascade test facility. The aeroelastic response phenomenon is studied in the influence coefficient domain having one blade oscillating in various three-dimensional rigid-body modes and measuring the unsteady response on several blades and at various radial positions. On the computational side a state-of-the-art industrial numerical prediction tool has been used that allowed for two-dimensional and three-dimensional linearized unsteady Euler analyses.</p><p>The results suggest that considerable three-dimensional effects are present, which are harming prediction accuracy for flutter stability when employing a two-dimensional plane model. These effects are mainly apparent as radial gradient in unsteady response magnitude from tip to hub indicating that the sections closer to the hub experience higher aeroelastic response than their equivalent plane representatives. Other effects are due to turbomachinery-typical three-dimensional flow features such as hub endwall and tip leakage vortices, which considerably affect aeroelastic prediction accuracy. Both effects are of the same order of magnitude as effects of design parameters such as reduced frequency, flow velocity level and incidence. Although the overall behavior is captured fairly well when using two-dimensional simulations notable improvement has been demonstrated when modeling fully three-dimensional and including tip clearance.</p>

The continuous trend in gas turbine design towards lighter, more powerful and more reliable engines on one side and use of alternative fuels on the other side renders flutter problems as one of the paramount challenges in engine design. Flutter denotes a self-excited and self-sustained aeroelastic instability phenomenon that can lead to material fatigue and eventually damage of structure in a short period of time unless properly damped. The design for flutter safety involves the prediction of unsteady aerodynamics as well as structural dynamics that is mostly based on in-house developed numerical tools. While high confidence has been gained on the structural side unanticipated flutter occurrences during engine design, testing and operation evidence a need for enhanced validation of aerodynamic models despite the degree of sophistication attained. The continuous development of these models can only be based on the deepened understanding of underlying physical mechanisms from test data. As a matter of fact most flutter test cases treat the turbomachine flow in two-dimensional manner indicating that the problem is solved as plane representation at a certain radius rather than representing the complex annular geometry of a real engine. Such considerations do consequently not capture effects that are due to variations in the third dimension, i.e. in radial direction. In this light the present thesis has been formulated to study three-dimensional effects during flutter in the annular environment of a low-pressure turbine blade row and to describe the importance on prediction of flutter stability. The work has been conceived as compound experimental and computational work employing a new annular sector cascade test facility. The aeroelastic response phenomenon is studied in the influence coefficient domain having one blade oscillating in various three-dimensional rigid-body modes and measuring the unsteady response on several blades and at various radial positions. On the computational side a state-of-the-art industrial numerical prediction tool has been used that allowed for two-dimensional and three-dimensional linearized unsteady Euler analyses. The results suggest that considerable three-dimensional effects are present, which are harming prediction accuracy for flutter stability when employing a two-dimensional plane model. These effects are mainly apparent as radial gradient in unsteady response magnitude from tip to hub indicating that the sections closer to the hub experience higher aeroelastic response than their equivalent plane representatives. Other effects are due to turbomachinery-typical three-dimensional flow features such as hub endwall and tip leakage vortices, which considerably affect aeroelastic prediction accuracy. Both effects are of the same order of magnitude as effects of design parameters such as reduced frequency, flow velocity level and incidence. Although the overall behavior is captured fairly well when using two-dimensional simulations notable improvement has been demonstrated when modeling fully three-dimensional and including tip clearance.