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Doctor of Philosophy / Department of Civil Engineering / Stefan A. Romanoschi / Permanent deformation (rutting) is the most critical load-associated distress that develops on asphalt pavements significantly affecting their performance. Past research work focused on estimating permanent deformation of asphalt mixes using empirical prediction models or prediction models based on linear elastic material models. In recent years, mechanistic and mechanistic-empirical prediction models have been developed to take into account the behavior of asphalt material (viscoelastic, viscoplastic or elasto-visco-plastic). This research project aims to evaluate existing mechanistic models that predict permanent deformation (rutting) in asphalt mixes by comparing computed permanent deformation to that measured in a full-scale accelerated pavement test. Six pavement sections were constructed in the Civil Infrastructure Systems Laboratory (CISL) of Kansas State University with six different asphalt mixes. The sections were loaded with up to 700,000 load repetitions of a 22,000lb single axle. The transverse profiles at the pavement surface were measured periodically. For material characterization, asphalt mix samples fabricated in the laboratory, were subjected to dynamic modulus (|E*|), static creep - flow time (Ft), dynamic creep - flow number (Fn), triaxial and uniaxial strength tests, repetitive shear at constant height (RSCH) and frequency sweep at constant height (FSCH). The finite element software, Abaqus, was used to simulate and evaluate four permanent deformation prediction models, which are: creep model, elasto-visco-plastic model, viscoelastic model and Drucker-Prager model. The predicted permanent deformation was then compared to permanent deformation measured in CISL for the six of asphalt pavement sections. It was found that, with some improvements, creep and elasto-visco-plastic models could be used to predict permanent deformation in asphalt mixes. The viscoelastic model greatly under-predict permanent deformation, and the Drucker-Prager model with hardening criteria over predicts permanent deformation as compared to values measured in CISL.

Experts in the field of molecular and cellular biology (MCB) use domain-specific reasoning strategies to navigate the unique complexities of the phenomena they study and creatively explore problems in their fields. One primary goal of instruction in undergraduate MCB is to foster the development of these domain-specific reasoning strategies among students. However, decades of evidence-based research and many national calls for undergraduate instructional reform have demonstrated that teaching and learning complex fields like MCB is difficult for instructors and learners alike. Therefore, how do students develop rich understandings of biological mechanisms? It is the aim of this dissertation work to explore features of expertise and knowledge building in undergraduate MCB by investigating knowledge organization and problem-solving strategies. Semi-structured clinical think-aloud interviews were conducted with introductory and upper-division students in MCB. Results suggest that students must sort ideas about molecular mechanism into appropriate mental categories, create connections using function-driven and mechanistic rather than associative reasoning, and create nested and overlapping ideas in order to build a nuanced network of biological ideas. Additionally, I characterize the observable components of generative multi-level mechanistic reasoning among undergraduate MCB students constructing explanations about in two novel problem-solving contexts. Results indicate that like MCB experts, students are functionally subdividing the overarching mechanism into functional modules, hypothesizing and instantiating plausible schema, and even flexibly consider the impact of mutations across ontological and biophysical levels. However "filling in" these more abstract schema with molecular mechanisms remains problematic for many students, with students instead employing a range of developing mechanistic strategies. Through this investigation of expertise and knowledge building, I characterize several of the ways in which knowledge integration and generative explanation building are productively constrained by domain-specific features, expand on several discovered barriers to productive knowledge organization and mechanistic explanation building, and suggest instructional implications for undergraduate learning.

Cellulose from energy crops or agriculture residues can be utilized as a sustainable energy resource to produce biofuels such as ethanol. The process of converting cellulose into solvents and biofuels requires the saccharification of cellulose into soluble, fermentable sugars. However, challenges to cellulosic biofuel production include increasing the activity of cellulose-degrading enzymes (cellulases) and increasing solvent (ethanol) yield while minimizing the co-production of organic acids. This work applies novel surface analysis techniques and fermentation reactor perturbations to quantify, manipulate, and model enzymatic and metabolic processes critical to the efficient production of cellulosic biofuels. Surface analysis techniques utilizing cellulose thin film as the model substrate are developed to quantify the kinetics of cellulose degradation by cellulase as well as the interactions with cellulase at the interfacial level. Quartz Crystal Microbalance with Dissipation (QCM-D) is utilized to monitor the change in mass of model cellulose thin films cast. The time-dependent frequency response of the QCM simultaneously measures both enzyme adsorption and hydrolysis of the cellulose thin film by fungal cellulases, in which a significant reduction in the extent of hydrolysis can be observed with increasing cellobiose concentrations. A mechanistic enzyme reaction scheme is successfully applied to the QCM frequency response for the first time, describing adsorption/desorption and hydrolysis events of the enzyme, inhibitor, and enzyme/inhibitor complexes. The effect of fungal cellulase concentration on hydrolysis is tested using the QCM frequency response of cellulose thin films. Atomic Force Microscopy (AFM) is also applied for the first time to the whole cell cellulases of the bacterium C. thermocellum, where the effect of temperature on hydrolysis activity is quantified. Fermentation of soluble sugars to desirable products requires the optimization of product yield and selectivity of the cellulolytic bacterium, Clostridium thermocellum. Metabolic tools to map the phenotype toward desirable solvent production are developed through environmental perturbation. A significant change in product selectivity toward ethanol production is achieved with exogenous hydrogen and the addition of hydrogenase inhibitors (e.g. methyl viologen). These results demonstrate compensatory product formation in which the shift in metabolic activity can be achieved through environmental perturbation without permanent change in the organism’s genome.

The Mechanistic Empirical Pavement Design Guide (MEPDG) developed by the National Cooperative Highway Research Program (NCHRP) project 1-37A, is a very powerful tool for the design and analysis of pavements. The designer utilizes an iterative process to select design parameters and predict performance, if the performance is not acceptable they must change design parameters until an acceptable design is achieved. The design process has more than 100 input parameters across many areas, including, climatic conditions, material properties for each layer of the pavement, and information about the truck traffic anticipated. Many of these parameters are known to have insignificant influence on the predicted performance During the development of this procedure, input parameter sensitivity analysis varied a single input parameter while holding other parameters constant, which does not allow for the interaction between specific variables across the entire parameter space. A portion of this research identified a methodology of global sensitivity analysis of the procedure using random sampling techniques across the entire input parameter space. This analysis was used to select the most influential input parameters which could be used in a streamlined design process. This streamlined method has been developed using Multiple Adaptive Regression Splines (MARS) to develop predictive models derived from a series of actual pavement design solutions from the design software provided by NCHRP. Two different model structures have been developed, one being a series of models which predict pavement distress (rutting, fatigue cracking, faulting and IRI), the second being a forward solution to predict a pavement thickness given a desired level of distress. These thickness prediction models could be developed for any subset of MEPDG solutions desired, such as typical designs within a given state or climatic zone. These solutions could then be modeled with the MARS process to produce am “Efficient Design Solution” of pavement thickness and performance predictions. The procedure developed has the potential to significantly improve the efficiency of pavement designers by allowing them to look at many different design scenarios prior to selecting a design for final analysis.

Palladium-catalyzed reactions for carbon-carbon bond formation have had a significant impact on the field of organic chemistry in recent decades. Illustrative is the 2010 Nobel Prize, awarded for “palladium-catalyzed cross couplings in organic synthesis”, and the numerous applications of these transformations in industrial settings. This thesis describes recent developments in C(sp2)-C(sp3) bond formation, focusing on alkane arylation reactions and arylative dearomatization transformations. In the first part, our contributions to the development of intramolecular C(sp3)-H arylation reactions from aryl chlorides are described (Chapter 2). The use of catalytic quantities of pivalic acid was found to be crucial to observe the desired reactivity. The reactions are highly chemoselective for arylation at primary aliphatic C-H bonds. Theoretical calculations revealed that C-H bond cleavage is facilitated by the formation of an agostic interaction between the palladium centre and a geminal C-H bond. In the following section, the development of an alkane arylation reaction adjacent to amides and sulfonamides is presented (Chapter 3). The mechanism of C(sp3)-H bond cleavage in alkane arylation reactions is also addressed through an in-depth experimental and theoretical mechanistic study. The isolation and characterization of an intermediate in the catalytic cycle, the evaluation of the roles of both carbonate and pivalate bases in reaction mechanism as well as kinetic studies are reported. Our serendipitous discovery of an arylation reaction at cyclopropane methylene C-H bonds is discussed in Chapter 4. Reaction conditions for the conversion of cyclopropylanilines to quinolines/tetrahydroquinolines via one-pot palladium(0)-catalyzed C(sp3)-H arylation with subsequent oxidation/reduction are described. Initial studies are also presented, which suggest that this transformation is mechanistically unique from other Pd catalyzed cyclopropane ring-opening reactions. Preliminary investigations towards the development of an asymmetric alkane arylation reaction are highlighted in Chapter 5. Both chiral carboxylic acid additives and phosphine ligands have been examined in this context. While high yields and enantiomeric excesses were never observed, encouraging results have been obtained and are supported by recent reports from other research groups. Finally, in part two, the use of Pd(0)-catalysis for the intramolecular arylative dearomatization of phenols is presented (Chapter 7). These reactions generate spirocyclohexadienones bearing all-carbon quaternary centres in good to excellent yields. The nature of the base, although not well understood, appears to be crucial for this transformation. Preliminary results in the development of an enantioselective variant of this transformation demonstrate the influence of catalyst activation on levels of enantiomeric excess.

This thesis concerns the use of various potent oxidants in organic synthesis. The main focus is directed at selectively introducing trifluoromethyl groups into compounds containing double or triple bonds. All reactions proceed under mild conditions and can in most cases be performed on the bench-top. We have developed three different procedures for transformations of activated alkenes and alkynes as well as quinones. In paper I the selective introduction of a trifluoromethyl group together with an oxygen functionality to double and triple bonds is demonstrated. Paper II is focused on the related chemoselective cyanotrifluoromethylation in which a cyano group is added instead of the oxygen functionality. Paper III describes a new procedure for C–H trifluoromethylation of quinones. Our studies on the mechanistic aspects of the above reactions are described in Paper IV. In these studies we investigated the ligand and substituent effects in Cu-catalyzed reactions. Paper V is focused on a conceptually new palladium-catalyzed allylic C–H acyloxylation of olefins under oxidative conditions. The procedure uses an inexpensive, safe and environmentally benign oxidant, sodium perborate, which is activated with acetic anhydride. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Submitted.</p>

Much research debates whether properties of ecological networks such as nestedness and connectance stabilise biological communities while ignoring key behavioural aspects of organisms within these networks. Here, we computationally assess how adaptive foraging (AF) behaviour interacts with network architecture to determine the stability of plant-pollinator networks. We find that AF reverses negative effects of nestedness and positive effects of connectance on the stability of the networks by partitioning the niches among species within guilds. This behaviour enables generalist pollinators to preferentially forage on the most specialised of their plant partners which increases the pollination services to specialist plants and cedes the resources of generalist plants to specialist pollinators. We corroborate these behavioural preferences with intensive field observations of bee foraging. Our results show that incorporating key organismal behaviours with well-known biological mechanisms such as consumer-resource interactions into the analysis of ecological networks may greatly improve our understanding of complex ecosystems.

This paper sets out to investigate the effects on small banks’ management control practices from increasing regulation following the 2008 financial crisis. The changes to banks’ management control practices may in turn have implications for banks’ competitive advantages and strategies. A qualitative case study of a Swedish savings bank was carried out, gathering data through six semi-structured interviews of representatives at different levels. Our findings indicate that the increased regulatory pressure has increased both the scope and scale of administrative as well as cybernetic controls. A relative change of focus, from business- to compliance-oriented was also detected in connection with the planning and cybernetic controls. The increase in mainly administrative controls and the resulting regulatory burden suggest that it may be difficult for small and decentralized banks to pursue their chosen strategy unless they are able to find alternative ways of dealing with this burden. / Uppsatsen redogör för vår undersökning av effekterna av ökande reglering på små, lokala bankers styrning i kölvattnet av 2008 års finanskris. Förändringarna av styrningen kan i sin tur ha betydelse för bankers komparativa fördelar, och deras strategier. En kvalitativ fallstudie av en svensk sparbank genomfördes och innefattade sex semi-strukturerade intervjuer av medarbetare på olika nivåer. Resultaten pekar på att det ökade regleringstrycket har ökat omfattningen av styrning kopplad till governance, organisationsstrukturer, policies och processbeskrivningar men även uppföljning. En förskjutning av fokus, från affärsorienterat mot compliance-orienterat, sågs också i anslutning till styrning som hade att göra med planering och uppföljning. Den betydande ökningen av styrning övervägande kopplad till governance, organisationsstrukturer, policies och processbeskrivningar antyder att det kan bli svårt för små lokala banker att behålla sin strategi om de inte lyckas finna alternativa sätt att hantera den ökade bördan som den förändrade styrningen innebär.

Cette thèse porte sur l’étude mécanistique de réactions mettant en jeu des complexes de palladium. Deux systèmes différents sont étudiés, mettant ainsi en évidence des approches mécanistiques à différents niveaux. La première étude réalisée concerne l’addition oxydante de complexes [palladium - ligands azotés] sur des iodoarènes. Une cinétique d’ordre 2 en palladium(0) a été mise en évidence expérimentalement, pour une grande variété de conditions (ligands, solvants, iodoarènes). Un mécanisme coopératif faisant intervenir l’activation de la liaison CI par un complexe de palladium, suivi par l’insertion oxydante d’un deuxième complexe de palladium a été proposé et étudié par DFT. La deuxième étude porte sur formation d’oxazolidine-2,4-diones à partir d’adduits de Passerini, catalysée au palladium. L’objectif est ici de déterminer les intermédiaires mis en jeu dans cette réaction impliquant la formation de 3 nouvelles liaisons sur le squelette carboné. Une double réaction de Tsuji-Trost a été mise en évidence et le rôle particulier de l’allylméthylcarbonate utilisé a été étudié. A la lumière de ces résultats, un cycle catalytique a été proposé. Cette étude montre le potentiel de la compréhension détaillée des phénomènes à l’échelle moléculaire pour imaginer de futurs développements. / In this thesis, the mechanistic study of reactions involving palladium complexes is presented. Two systems have been studied, with different levels of mechanistic investigation. The first study aims at explaining the peculiar behavior of palladium ligated to nitrogen-containing ligands in the oxidative addition on iodoarenes. A second order in palladium(0) reaction rate has been experimentally demonstrated for various conditions (ligand, solvent, iodoarene). A cooperative mechanism involving the pre-activation of the C-I bond by a palladium complex prior to the oxidative insertion itself has been proposed and studied by DFT. In the second study, the palladium-catalyzed formation of oxazolidine-2,4-diones from Passerini adducts is investigated. The goal is to determine the relevant intermediates of the reaction and to explain the formation of the three new bonds. Two Tsuji-Trost reactions occur and the special role of allylmethylcarbonate has been studied. This mechanistic study highlights the potential of thorough understanding of mechanisms at the molecular level to envision further synthetic developments.