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The present work was performed at HVDC ABB as an initial study on how to adopt probabilistic concepts into the VCSHVDC insulation coordination. Due to large voltage levels in HVDC applications the corresponding insulation need to be properly addressed to ensure a safe, economical and reliable operation. Traditionally, only the maximum overvoltage is considered, where no adoption to the shape of the overvoltage distribution is regarded. Use of probabilistic concepts in the insulation coordination procedure can ideally reduce insulation margins with a maintained low risk of flashover. Analysis and understanding of probabilistic concepts of AC systems is needed in order to implement the concepts into VSC-HVDC. With use of advanced VSC-HVDC models, faults are simulated with varied fault insertion time in PSCAD. The resulting overvoltages from the simulation is gathered using different statistical methods in order to obtain the approximated overvoltage distribution. It was found from the simulation results that use of a Gaussian distribution is inappropriate due to shape variety in the overvoltage distributions. Instead, Kernel Density Estimate can serve as a flexible tool to approximate overvoltage distributions with a variety in number of modes and shape. The retrieved approximated overvoltage distributions are compared with the insulation strength in order to calculate the risk of flashover. The comparison shows that the insulation can be tuned in order to match set requirements. The thesis work should be seen as pilot study, where key problems have been pointed out and recommended further studies are proposed.

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The study attempts to determine 1) whether or not consumers want to choose colors for interior goods; 2) whether they agree as to which interior items are most important for color selection; and, 3) whether they prefer to coordinate interior colors for themselves or choose from pre-coordlnated color schemes.

Group coordination is a universal feature of social life. Animals form social groups for a variety of reasons, including predator evasion and more efficient foraging, and individuals living in social groups must coordinate their activities in order for groups to function. Consequently, the factors that facilitate or impede group coordination are of great interest in understanding the lives of social animals. Familiarity between individuals has well-documented effects on group coordination, with familiar groups outperforming unfamiliar ones in predator evasion, foraging, and cohesion. Individuals also generally prefer to coordinate with familiar conspecifics over unfamiliar ones. Despite these advantages, the mechanisms through which familiarity might aid group coordination are poorly understood. Similarly, the individual personalities of group members have well-documented effects on group performance: bold individuals are more likely to be 'leaders' and determine the direction of group movements, and groups comprised of individuals of differing personalities outperform groups of all bold or all shy individuals. While the effect of individual personalities on group behaviour has been recorded extensively, the ways in which individuals affect each other's behaviour are still poorly documented. In particular, active interactions where one individual can directly affect the behaviour of others have received limited attention, as it is difficult to distinguish such actions from passive effects. I used two systems to investigate how individual behaviours can lead to group coordination. In three-spined sticklebacks (Gasterosteus aculeatus), well-established boldness assays allowed me to assess the effects of personality and familiarity on 1) coordination between pairs of fish; I found that individuals in unfamiliar pairs exhibited coordination patterns consistent with their individual personalities, with bold individuals more likely to leave cover independently, while in familiar pairs, individuals behaved in ways seemingly unrelated to their boldness scores. I also investigated how personality and familiarity affect 2) group coordination and individual performance in a problem-solving paradigm. I found that familiarity, relative individual personality, and group mean personality interact to affect individual foraging success, and that group cohesion was affected by the interaction of group familiarity and group mean personality. These results suggest that individual characteristics can impact the behaviour of groups, and that the characteristics of an individual's group can in turn affect an individual's behaviour and success. In the Bronze Cory catfish (Corydoras aeneus), I described a novel tactile interaction style termed 'nudging' that individuals use during group coordination. I investigated 3) the effect of familiarity on nudging and coordination in pairs and triplets. These results show that nudging can be used to overcome the disadvantages of familiarity, which has important implications for how communication can underlie group coordination in the absence of familiarity. I then investigated how 4) nudging affects group coordination following a flight response to a potential threat. I demonstrated that nudging leads to a higher likelihood of group cohesion and longer group flight times. This shows how active interactions can mediate group responses and affect the ecologically relevant scenario of predator evasion. Finally, I investigated 5) the development of this nudging behaviour. My results show that Bronze Cory catfish larvae develop toleration for tactile stimulation with age alongside their propensity to nudge conspecifics. This suggests that Bronze Cory catfish larvae require social feedback to develop appropriate responses to nudges from conspecifics and supports the important role of nudging in Bronze Cory catfish sociality. The presence of active interactions in the Bronze Cory catfish` modifies the way that social behaviour manifests in this species and has great potential for further questions about social behaviour and group functioning.

In Chapter One, the sodium salt of tris (2-oxo-1-t-butylimidazolyl) hydroborate, [To^But]Na, as an [O_3] donor ligand has been prepared. The yield for this reaction was low because there is a significant amount of side product in which the double bond of the oxoimidazole starting material is reduced. Treatment of sodium borohydride with bezannulated oxoimidazole at high temperature leads to the generation of the sodium salt of tris (2-oxo-1-R-methylbenimidazolyl) hydroborate in high yield, [To^RBenz]Na. These ligands have been prepared with different alkyl substituents, methyl, t-butyl and adamantyl, to achieve the desired steric environment. Furthermore, these benzannulated ligand have been used to synthesize a series [To^RBenz]Tl complexes, which exist as a discrete mononuclear complexes in the solid state. Finally, [To^RBenz]Tl complexes are more pyramidal than the sulfur counterpart, [Tm^RBenz]Tl, but less pyramidal than those in the tris (pyrazolyl)hydroborato counterpart, [Tp^R,R]]Tl. In Chapter Two, the properties of [To^R] ligands have been evaluated versus related L_2X ligands. [To^R] ligands are substantially more sterically demanding than the corresponding [Tm^R] sulfur donor ligand and related [O_3] donor ligands. However, electronically, the [To^R] ligands exhibit weaker electron donating properties than other L_2X type ligands. Finally, the coordination chemistry of [To^R] ligands with various metal compounds has been briefly investigated. The synthesis of a new class of bidentate ligands has been detailed in Chapter Three. Namely the bis(2-oxo-1-t-butylimidazolyl)hydroborato and bis (2-oxo-1-alkylbenzimidazolyl)hydroborato, [Bo^But] and [Bo^RBenz], have been synthesized via the reaction of MBH_4 with two equivalents of the respective 2-imidazolone. Chelation of [Bo^But] and [Bo^MeBenz] to a metal center results in a flexible 8-membered ring that is capable of adopting a "boat-like" conformation that allows for secondary M—H—B interactions. Chapter Four describes the synthesis of [Bo^RBenz]_2Zr(CH_2Ph)_2and [To^RBenz]Zr(CH_2Ph)_3 with different alkyl substituents. Treatment of [To^ButBenz]Zr(CH_2Ph)_3 with ([PhNHMe_2][B{C_6F_5}_4]) in a coordinating solvent, Et_2O, generates {[To^ButBenz]Zr(CH2Ph)_2(OEt_2)}{B(C_6F_5)_4} which exhibit a very low activity for ethylene polymerization. However, a coordinatively unsaturated cationic zirconium alkyl complex was obtained by the treatment of ([PhNHMe_2][B{C_6F_5}_4]) with [To^ButBenz]Zr(CH_2Ph)_3 or [To^AdBenz]Zr(CH_2Ph)_3 which generate [To^ButBenz]Zr(CH_2Ph)_2[B(C_6F_5)_4 or [To^AdBenz]Zr(CH_2Ph)_2[B(C_6F_5)_4], respectively. Moderate activity for ethylene polymerization was obtained for t-butyl while high activity was obtained for the adamantyl derivatives. Finally, Chapter Five describes the synthesis of new oxygen-rich ligands, namely tris (2-pyridonyl)methane, [Tpom^R]H. They are obtained via the reaction of 2-pyridones with CHX_3 and K_2CO_3 in the presence of [Bu^n _4N]Br, followed by acid-catalyzed isomerization with camphorsulfonic acid. These compounds provide access to a new class of L_3X alkyl ligands that feature oxygen donors and are capable of forming metallacarbatranes, as exemplified by [Κ^4-Tpom^But]ZnOC6H4Bu^t. In addition, the [Tpom^But] ligand also allows isolation of a monovalent thallium alkyl compound, [Tpom^But]Tl, in which the Tl—C bond is long and has little covalent character.