Single-pass frequency conversion by a nonlinear optical crystal is an attractive method to generate coherent radiation in various spectral domains from ultraviolet to mid-infrared. Wavelength converters based on quasi-phase matched (QPM) periodically poled lithium niobate (PPLN) have proved to be important wavelength conversion devices for many useful applications. This thesis develops a novel integration design for temperature controlling and temperature wavelength tuning of a QPM-PPLN waveguide wavelength converter. A Cr/Pt/Au thin film alloy layer is deposited on a PPLN device with a polymer buffer layer to work as a micro-heater and a temperature sensor at the same time. The temperature of the device can be tailored by applying current to the micro-heater layer, which changes the effective period of the QPM grating and thus the QPM wavelength through the thermal optical effect (TOE). The device's temperature can be monitored by measuring the resistance change of the alloy layer. Micro-heater design and mode profile simulation are involved in the thesis. The entire device fabrication process is introduced. Both electrical and optical features of the device are characterized and discussed. In contrast to the conventional temperature tuning method based on a bulky oven, the proposed design has some excellent characteristics such as compact package size and low power consumption. / Thesis / Master of Applied Science (MASc)

Granular materials, such as sand, are systems consisting of huge numbers of particles that interact with each other through inter-particle contacts. Different from continuum materials, a granular material displays distinctive features due to the discrete nature of the microstructure, characterized by a spatial arrangement of inter-particle connection as well as a force-chain network. With a consideration of the contact force, the overall contact network is divided into a strong sub-network and a weak sub-network that carry contacts with normal contact forces larger and lower than the average normal contact force, respectively. Thus, the fabric anisotropy for different contact networks, are employed to characterize the microstructure of the granular material. In this research, the behavior of granular materials subjected to quasi-static shear was extensively investigated in terms of the fabric evolution including the magnitude and direction of anisotropy for different contact networks. Both statistical and micromechanical approaches were adopted to obtain the macroscopic properties, such as the fabric tensor, Cauchy stress tensor and the second-order work, in terms of the micro-scale variables. The discrete element method (DEM) was employed to simulate laboratory tests along fixed loading paths; for example, 2D tests along proportional strain paths, 2D simple shear tests and 3D tests along radial stress paths on the π-plane. Results demonstrated that the induced fabric anisotropy for the overall contact network can be related to the deviatoric stress ratio for both two-dimensional and three-dimensional conditions. The relation was found to be not unique, depending on the loading paths as well as the stress state. Nevertheless, a unique linear fabric-stress relation was presented between the stress tensor and fabric tensor for the strong sub-network. Specifically, the obliquity of this linear relation was found to be a function of the mean stress. This description held true for initially isotropic specimens subjected to proportional and non-proportional loading paths. On the other hand, for the initially anisotropic specimen, this correspondence only worked at the critical stress state. According to Nicot and Darve (2006), the macro second-order work cannot be interpreted as a summation of the local second-order work from the contact plane. The second-order work induced by the fabric evolution and the volumetric change must also be taken into account. The second-order work induced by the fabric evolution cannot be neglected in 2D analysis along proportional strain paths. Moreover, the vanishing of the second-order work is related to the fabric anisotropy in contact sub-networks that the decrease of fabric anisotropy for the weak sub-network or the degradation of weak sub-network was observed to be an indicator of deformation instability even though the strong sub-network dominants the shear resistance. The degradation of strong sub-network was a necessary but not a sufficient condition of instability. The direction of the fabric anisotropy for the strong sub-network was observed to be coaxial with the orientation of the principal stress. The principal direction of fabric anisotropy for the weak sub-network was always perpendicular to that of the strong sub-network, regardless of whether the principal stress rotated or not. For the overall contact network, however, the direction of the fabric anisotropy was not necessarily in line with the major principal stress direction, even for an initial isotropic granular assembly. Therefore, the finding by Radjaï et al.(1998) that the direction of the fabric anisotropy for the weak sub-network is perpendicular to that for the overall contact network only held true for the loadings in which the critical stress could be approached no matter if the principal stress orientation rotated or not. Under this circumstance, the fabric anisotropy for the overall contact network could be interpreted as a function of sub-networks’ anisotropy weighted by the ratio of contact number in each sub-network over the total number of contacts. At critical state, both the strong sub-network and the overall contact network developed high fabric anisotropy with the weak sub-network being mostly isotropic. When plotted on the π-plane, both the fabric anisotropy for the strong sub-network and the fabric anisotropy for the overall contact network depended on the stress paths but were independent of the mean stress level. The response surface of the former could be expressed as a Lade’s surface. The response envelope of the latter was an inverted Lade’s surface. / Dissertation / Doctor of Philosophy (PhD) / In civil engineering, granular materials are ubiquitous, such as sand, gravel, rock, and concrete. Due to the discrete nature of microstructure, this type of material usually displays exceedingly complicated behaviours under shear, for example, dilatancy, non-coaxiality, critical state, instability, and anisotropy. These mechanical responses are notoriously difficult to model and most existing models are phenomenological and lack a clear physical meaning. To provide a clear physical meaning for the constitutive model of granular material, the current study explored the evolution of the microstructure within the granular material subjected to quasi-static shear and the micromechanical origins of those macroscopic behaviours such as critical state, non-coaxiality, and instability. Both micromechanical analysis and discrete element method were applied. Results showed that the evolution of the whole microstructure depended on the loading condition. However, the evolution of the microstructure joined by the ‘strong contacts’ was independent of the loading path. At critical state, the microstructure was highly anisotropic, not unique and depended on the stress paths. The rearrangement of the microstructure helped to maintain the stability of a granular material. The instability of the granular material was triggered by the failure of the microstructure joined by the ‘weak contacts’.

The objectives of this research were to (a) explore nursing educators' experiences of integrating cultural safety in nursing education, (b) describe the strategies that nurse educators use, and (c) identify the barriers and possible solutions to facilitate the integration of cultural safety into nursing education. Indigenous Research Methodology was used to gain insight into nurse educators' experiences of integrating cultural safety in nursing education. Conducted in Ontario with 15 participants from 11 of the 14 accredited SON across Ontario. Conversing and listening to personal stories was the primary knowledge-seeking method. A harmonized narrative and thematic approach were used to analyze the conversations and stories from nurse educators. The results demonstrated the current colonial structure of nursing education is incompatible with and a barrier to the integration of cultural safety. As a consequence, this study reveals more barriers than strategies for integration, which demonstrates the substantial need for leadership, resources, and institutional support to integrate cultural safety. Current approaches have amplified forms of structural violence experienced by Indigenous nurse educators. This form of violence has been labeled a sophisticated type of racism that manifests in ways such as tokenism and othering of Indigenous nurse educators. Information about barriers, challenges and successes experienced by study participants supports recommendations for the dismantling of colonial discourses that are pervasive in nursing education and a barrier to integration of cultural safety. This study of integrating cultural safety supported the problematic nature of decolonization and Indigenization approaches as solutions to ensure cultural safety. Micro-reconciliation was identified as a possible solution to promote successful integration of cultural safety in nursing education. / Thesis / Master of Science in Nursing (MSN)

A biological investigation of the apparently intimate and mutually relationship exist­ing between certain plant-like micro-organisms and certain insects. The literature of the subject is briefly re­viewed and discussed and a critical appraisal of previous work is made. A problem, the association of certain micro-organisms with two species of grain feeding wee­vils, is discussed in greater detail and a method of approach is proposed and analysed. Studies of the micro-organisms in vivo and in vitro are described in conjunction with investigations, by experimental techniques, of the associa­tion of the micro-organisms and the weevils. Findings are discussed and conclusions are presented. / Thesis / Doctor of Philosophy (PhD)

In recent years, the electrification of technology that is traditionally powered by fossil fuels has become a popular means to reduce greenhouse gases (GHG). Although the intentions are well founded, the strain on the electrical grid is seldom taken into consideration. When there is increased load on the grid, it is typically met by fossil fuel peaking power plants or additional fossil fuel infrastructure. Depending on the electrical generation technology deployed and the power plant efficiency, electrification can result in an increase in GHG emissions. To make better informed decisions for GHG reductions, policy makers and engineers are in need of smart energy systems, such as the Integrated Community Energy and Harvesting (ICE-Harvest) system. ICE-Harvest systems work with and can respond to changes on the electrical grid, providing demand response. The system creates electrical demand when renewable generation sources are available, reduces demand when fossil fuel generation is present, and can offset centralized generation using distributed combined heat and power resources. In this thesis, steps to design a micro-thermal network (MTN) for the ICE-Harvest system are outlined and different operational strategies are explored that respond to grid behaviour in real time. How fast the thermal network reacts to grid level variations is defined as the response time. The physical response of the thermal network is a temperature set point change. A design map was developed presenting multiple parameters that contribute to the response time, the trade-offs between them, and the corresponding temperature difference achievable. Through developing models in the equation-based object-oriented software Dymola, the viability for real time temperature set point changes in micro-thermal networks was explored. The MTN and the energy transfer stations (ETSs) that transfer energy between the thermal network and the buildings have been modeled. Yearly system simulations were conducted to analyze the corresponding performance of the MTN in terms of electrical requirements and overall GHG emissions. An operational range of the system was presented demonstrating the flexibility of the ICE-Harvest system. The simulation results have identified the ICE-Harvest system as a viable means to provide demand response to the grid and to reduce GHG emissions. Future work and recommendations will be made to improve the response of the system and further reduce electrical consumption and GHG emissions. / Thesis / Master of Science in Mechanical Engineering (MSME)

En la presente tesis se estudia el comportamiento de un reactor estructurado de canales paralelos para llevar a cabo el proceso de reformado de etanol con vapor (ESR) para la generación de hidrógeno o gas de síntesis. Se desarrolla un modelo unidimensional pseudohomogéneo en estado estacionario para la simulación del comportamiento del micro-reactor. Se propone un diseño del reactor donde una corriente de gases calientes provenientes de una cámara de combustión externa suministra el calor necesario a la reacción de reformado. Se analiza la influencia de diferentes tamaños de canales y variables operativas sobre la performance del microreactor operando bajo dos configuraciones de flujo diferentes: co-corriente y contracorriente. Las variables analizadas afectan al suministro de calor y por lo tanto a la producción de H2. En la búsqueda de un modelo más riguroso, se desarrolla un modelo unidimensional heterogéneo para el mismo diseño del reactor, en el cual se considera la conducción de calor axial a través de las paredes metálicas del micro-reformador. Se realiza un estudio comparativo de ambos modelos, pseudohomogéneo y heterogéneo, y se analiza nuevamente la influencia del tamaño del canal para el modelo heterogéneo sobre la producción de hidrógeno y el rendimiento a metano para ambos esquemas de flujo (co- y contra-corriente). Se verifica el impacto del espesor de la pared sobre el fenómeno de conducción de calor axial a través de la pared metálica. Por último se propone una alternativa en la forma de suministrar el calor a las reacciones de reformado. La misma consiste en el acoplamiento térmico de reacciones exo- y endo-térmicas. En este diseño de reactor, por ciertos canales circula la corriente de proceso (ESR, reacción endotérmica) y por canales adyacentes se lleva a cabo la combustión de etanol (reacción exotérmica). Para la implementación del modelo matemático unidimensional heterogéneo, fue necesario realizar un estudio cinético de la reacción de combustión de etanol. Se estudia la influencia de la geometría de los canales y de distintas variables operativas sobre el comportamiento de ambas corrientes (ESR y combustión de etanol). Para completar el análisis del micro-reactor con acoplamiento de reacciones, se propone un diseño del sistema de reacción con precalentamiento de las alimentaciones aprovechando la energía de las corrientes de salida. / The present Thesis focuses on the study of a parallel-channels structured microreactor for hydrogen or synthesis gas production by ethanol steam reforming. A steady state 1D pseudohomogeneous mathematical model is developed to simulate the microreactor behavior. A reactor design where a flue-gas stream from an external combustor provides the heat necessary for the reforming reaction is proposed. The microreactor performance as affected by the channel dimensions and the operative variables is studied for two different flow configurations: cocurrent and countercurrent schemes. The analyzed variables affect the heat supply and, consequently, the hydrogen production. Aiming a more rigorous model for the reforming microreactor, a 1D heterogeneous model considering axial heat conduction through the solid wall is developed. A comparative study between both models, pseudohomogeneous and heterogeneous, is performed and the influence of the channel width over the hydrogen production and the methane yield is analyzed for this heterogeneous model and for both flow configurations (co- and countercurrent). The impact of the wall thickness over the axial heat conduction through the metallic wall is verified. Finally, the coupling of exothermic and endothermic reactions is proposed as an alternative method to supply the heat necessary for the reforming reaction. In this design, the process stream (ESR, endothermic reaction) circulates for certain channels and ethanol combustion (exothermic reaction) is conducted in adjacent channels. A kinetic study of the ethanol catalytic combustion reaction was made in order to implement the 1D heterogeneous math model with thermally coupled reactions. The influence of the channel width and the different operative variables over the behavior of both streams (ESR and ethanol combustion) is studied. To complete the analysis of this microreactor design, the preheating of the feed streams recovering heat from the reactor outlet in external heat exchangers is studied.

While social constructionist understandings of the self have stressed the importance of the self—other relation, placing emphasis on what happens in dialogues and relations with others rather than psychological processes “in the head,” I suggest here that we can build on this tradition to reintroduce notions of a dialogue with the self, or micro-dialogue, as an important part of an understanding of persons. I use the term “microdialogue,” rather than the more familiar notion of “internal conversation” or “society of mind,” to refer to a silent and invisible series of dialogues we hold for ourselves with the images and voices of others, which can emerge in surprising and unwilled ways. I suggest that this micro-dialogue is important in understanding the dialogical interactions between persons, as not all aspects of the self will enter into dialogue with others, leading to miscommunication, misunderstanding, and misrecognition. It is also possible for people to fail to articulate all the latent voices or vocal tones in their own micro-dialogue, leading to an understanding of how voices and selves can become divided and allowing us to take a different perspective on a dialogical unconscious.

Simulating the complex physics and dynamics associated with unsteady aeroelastic systems is often attempted with high-fidelity numerical models. While these high-fidelity approaches are powerful in terms of capturing the main physical features, they may not discern the role of underlying phenomena that are interrelated in a complex manner. This often makes it difficult to characterize the relevant causal mechanisms of the observed features. Besides, the extensive computational resources and time associated with the use these tools could limit the capability of assessing different configurations for design purposes. These shortcomings present the need for the development of simplified and reduced-order models that embody relevant physical aspects and elucidate the underlying phenomena that help in characterizing these aspects. In this work, different fluid and aeroelastic systems are considered and reduced-order models governing their behavior are developed. In the first part of the dissertation, a methodology, based on the method of multiple scales, is implemented to show its usefulness and effectiveness in the characterization of the physics underlying the system, the implementation of control strategies, and the identification of high-impact system parameters. In the second part, the unsteady aerodynamic aspects of flapping micro air vehicles (MAVs) are modeled. This modeling is required for evaluation of performance requirements associated with flapping flight. The extensive computational resources and time associated with the implementation of high-fidelity simulations limit the ability to perform optimization and sensitivity analyses in the early stages of MAV design. To overcome this and enable rapid and reasonably accurate exploration of a large design space, a medium-fidelity aerodynamic tool (the unsteady vortex lattice method) is implemented to simulate flapping wing flight. This model is then combined with uncertainty quantification and optimization tools to test and analyze the performance of flapping wing MAVs under varying conditions. This analysis can be used to provide guidance and baseline for assessment of MAVs performance in the early stages of decision making on flapping kinematics, flight mechanics, and control strategies. / Ph. D.

Cooperative Extension (CE) is a nationwide system that addresses leading concerns for United States residents from agricultural production to healthy youth development. As 80% of Americans are not meeting the Physical Activity Guidelines (PAG), promoting physical activity is a recent addition to CE priority areas. To build capacity of CE to offer physical activity, training on physical activity within the system is needed. Since yoga is a public health intervention growing in popularity due to its link to flourishing and mental well-being, this is a holistic practice that may target physical and mental health in the United States. Due to the variety of yoga practices one could engage with it is important to clarify the link between physical activity and yoga. This dissertation included four studies to promote physical activity and yoga within CE. Study one established the efficacy of a virtual micro-credentialing program for CE professionals (N = 64) that increased their knowledge about physical activity programming and increased their own physical activity levels. The second study was an iterative and pragmatic investigation of wellness initiatives for CE professionals to increase flourishing and physical activity within themselves. The third study explored the degree to which temperature and tempo of yoga classes impacted measured heart rate and rate of perceived exertion. Preliminary evidence suggests that ~30% of the yoga class contributed to moderate-vigorous physical activity, regardless of the temperature and speed. The fourth study was a systematic appraisal of urban and rural yoga studio offerings. The results included that most studios offer 60-minute classes, focused on asana (movement) rather than the other limbs (components) of yoga. This work also resulted in a studio audit form for CE professionals to assess yoga studios for appropriateness to recommend to their participants. Future work includes scaling out the micro-credentialing program and determining the degree to which knowledge of physical activity leads to physical activity program adoption (study 1); ensuring CE professionals have access to wellness initiatives to avoid burn out (study 2); ongoing investigation of the physiological benefits of yoga (study 3); and testing the utility of the studio audit form (study 4). / Doctor of Philosophy / Physical activity is an important part of living a healthy life and can look different for everyone. The Physical Activity Guidelines for Americans recommend for people to get 2 days of full body strength training along with 150 minutes of moderate intensity aerobic activity each week. Aerobic activity is activity that gets your heart rate up. In the first manuscript of this dissertation, Cooperative Extension professionals were trained in how to promote physical activity and physical activity programming. Cooperative Extension is a nationwide program that helps get research knowledge from the universities to the public. The second manuscript looks at how Cooperative Extension professionals were able to incorporate more mindfulness, yoga, and self-care for themselves through employee wellness programs, and which programs worked best in a practical way. The third manuscript looks at if the physical practice of yoga can increase heart rate to moderate to vigorous intensity zones in order to determine if a typical community-based yoga flow could contribute to meeting the aerobic components of the Physical Activity Guidelines. Based on this study, yoga can help participants get into the moderate intensity aerobic activity zone. The fourth manuscript explores the research and development of a yoga studio audit tool. This tool helps assess yoga studios so that public health professionals can recommend the studio that is the right fit for their clients.

This thesis presents the design and evaluation of an operating system kernel specially designed for dataflow software. Dataflow is a style of software architecture that is well suited for control and "signal flow" applications. This architecture involves many small processes and lots of inter-process communication, which impose too much overhead on traditional RTOSes. This thesis describes design and implementation of the Dataflow Architecture Real-time Kernel (DARK). DARK is a reconfigurable, multithreaded and preemptive operating system kernel that introduces a special data-driven scheduling strategy for dataflow applications. It uses the underlying hardware for high-speed context switching between the kernel and applications, which is five times faster than the ordinary context switch. The features of the kernel can be configured according to performance requirements without change to the applications. Along with the performance evaluation of DARK, the performance comparison results of DARK with two commercial RTOSes: MicroC/OS-II and Analog Devices VDK++ are also provided. / Master of Science