In the past decades, a great variety of model fitting and model free (isoconversional) methods have been developed for extracting kinetic parameters for solid state reactions from thermally stimulated experimental data (TGA, DSC, DTA etc.). However, these methods have met with significant controversies about their methodologies. Firstly, model-fitting methods have been strongly criticized because almost any reaction mechanism can be used to fit the experimental data satisfactorily with drastic variations of the kinetic parameters, and no good criterion exists to tell which mechanism is the best choice. Secondly, previous model free methods originated from the isoconversional principle, which is often called the basic assumption; previous studies comparing the accuracy of model free methods have not paid attention to the influence of the principle on model free methods and, therefore, their conclusions are problematic. This work gives, firstly, a critical study of previous methods for evaluating kinetic parameters of solid state reactions and a critical analysis of the isoconversional principle of model free methods. Then an analysis is given of the invariant kinetic parameters method and recommends an incremental version of it. Based on the incremental method and model free method, a comprehensive method is proposed that predicts the degree of the dependences of activation energy on heating programs, and obtains reliable kinetic parameters. In addition, this work also compares the accuracy of previous methods and gives recommendations to apply them to kinetic studies.

The development of a sustainable manufacturing process requires a comprehensive evaluation method and fundamental understanding of the processes. Coolant application is a critical sustainability concern in the widely used machining process. Cryogenic machining is considered a candidate for sustainable coolant application. However, the lack of comprehensive evaluation methods leaves significant uncertainties about the overall sustainability performance of cryogenic machining. Also, the lack of practical application guidelines based on scientific understanding of the heat transfer mechanism in cryogenic machining limits the process optimization from achieving the most sustainable performance. In this dissertation, based on a proposed Process Sustainability Index (ProcSI) methodology, the sustainability performance of the cryogenic machining process is optimized with application guidelines established by scientific modeling of the heat transfer mechanism in the process. Based on the experimental results, the process optimization is carried out with Genetic Algorithm (GA). The metrics-based ProcSI method considers all three major aspects of sustainable manufacturing, namely economy, environment and society, based on the 6R concept and the total life-cycle aspect. There are sixty five metrics, categorized into six major clusters. Data for all relavant metrics are collected, normalized, weighted, and then aggregated to form the ProcSI score, as an overall judgment for the sustainability performance of the process. The ProcSI method focuses on the process design as a manufacturer’s aspect, hoping to improve the sustainability performance of the manufactured products and the manufacturing system. A heat transfer analysis of cryogenic machining for a flank-side liquid nitrogen jet delivery is carried out. This is performed by micro-scale high-speed temperature measurement experiments. The experimental results are processed with an innovative inverse heat transfer solution method to calculate the surface heat transfer coefficient at various locations throughout a wide temperature range. Based on the results, the application guidelines, including suggestions of a minimal, but sufficient, coolant flow rate are established. Cryogenic machining experiments are carried out, and ProcSI evaluation is applied to the experimental scenario. Based on the ProcSI evaluation, the optimization process implemented with GA provides optimal machining process parameters for minimum manufacturing cost, minimal energy consumption, or the best sustainability performance.

A challenge for fire researchers is obtaining data from those fires that are most dangerous and costly. While it is feasible to instrument test beds, test plots, and small prescribed burns for research, it is uncommon to successfully instrument an active wildland fire. With a focus on very specific facets of wildland fire, researchers have created many unique models utilizing matchsticks, cardboard, liquid fuel, excelsior, plywood, live fuels, dead fuels, and wood cribs of different packing densities. Such scale models, however, only serve as valid substitutes for the full-scale system when all functional relations of the scale model are made similar to corresponding relations of the original phenomena. The field of study of large wildland fires therefore was in need of a framework that researchers could use to relate the results from many previous experiments to full-scale wildland fires; this framework was developed during the research for this dissertation. This further work developing laws for instability scaling in wildland settings was founded on the established work in dynamic similitude of G.I. Taylor, H. C. Hottel, F. A. Williams, R. I. Emori, K. Saito and Y. Iguchi. Additionally, in this work, a new dynamic flame parameter was incorporated into the scaling laws for fires that had not previously been assessed and proved to provide additional, important insight into flame spread. The new dynamic parameter enabled improved St-Fr correlations and was established for a wide range of fire sizes and fuel types.

Prescribed burning is an important management tool for the restoration and maintenance of tallgrass prairies. To improve fire behaviour prediction in tallgrass prairies, I assessed three different aspects of fire behaviour - heat of combustion, fuel load and rate of spread. Heat of combustion was found to vary amongst certain tallgrass species but the relatively small differences in means is unlikely to contribute significantly to fire behaviour. Average fuel loads in Ontario tallgrass prairie sites were found to be higher than current default value used in fire behaviour prediction. Three rapid fuel load assessment techniques were tested. Finally, the predictions of three fire behaviour prediction systems - the FBP System, BehavePlus and an Australian grassfire spread model, were compared with actual fire behaviour observations. The FBP System was found to perform poorly while both BehavePlus and the Australian model exhibited relatively strong relationships between observed and predicted rates of spread.

Prescribed burning is an important management tool for the restoration and maintenance of tallgrass prairies. To improve fire behaviour prediction in tallgrass prairies, I assessed three different aspects of fire behaviour - heat of combustion, fuel load and rate of spread. Heat of combustion was found to vary amongst certain tallgrass species but the relatively small differences in means is unlikely to contribute significantly to fire behaviour. Average fuel loads in Ontario tallgrass prairie sites were found to be higher than current default value used in fire behaviour prediction. Three rapid fuel load assessment techniques were tested. Finally, the predictions of three fire behaviour prediction systems - the FBP System, BehavePlus and an Australian grassfire spread model, were compared with actual fire behaviour observations. The FBP System was found to perform poorly while both BehavePlus and the Australian model exhibited relatively strong relationships between observed and predicted rates of spread.

There is interest concerning the energy performance of buildings in the United States. Buildings, whether residential, commercial or institutional, generally underperform in terms of energy efficiency when compared to buildings that are constructed following sustainably and energy efficiency standards. A substantial percentage of energy loss in these buildings is associated with the thermal efficiency of its envelope (exterior walls, windows roof, floors and doors). The objective of this study will evaluate the results of three energy modeling techniques developed to investigate the energy transfer through the envelope of existing campus buildings. The techniques employed are solving the heat transfer calculations using spreadsheets, using a stand-alone modeling software (OpenStudio) and using an integrated building energy modeling software (eQuest) employed in Autodesk Revit. The first technique is somewhat different from the other two because it does not require a 3D representation of the building to be generated as the first step in the modeling process. It is the application of a mathematical methodology employing heat transfer algorithms entered into the spreadsheet’s cells to estimate the heat transfer through the building envelope. Data needed for this technique are weather data of the buildings location, surface area of the building envelope, and the overall heat transfer coefficient (U-value) of each component of the building envelope. The OpenStudio technique involves a 3D representation of the building. The building is drawn on a 3D modeling computer program called SketchupPro, which communicates directly to the OpenStudio energy modelling interface. The building operations as well as the building characteristics, such as the composition and type of the elements that made up the building envelop, the thermal zone, occupancy schedule and the space type was inputted in the OpenStudio engine. The OpenStudio engine runs the simulation and generates a detail result about the energy usage and energy transfer in the building. The third method that employs AutoCAD Revit software is a standalone technique that does not require an external software for sketching the building model. Revit the ability to draw the model as well as perform the energy analysis at the same time with the aid of inbuilt eQuest modeling engine. The model in Revit is generated with the right building envelope characteristics as the existing building and the weather file. The process is somewhat similar to the OpenStudio technique; the main difference is the level of detail and limitation provided by both the energy modeling engine (eQuest and EnergyPlus). At the end of the simulation, the building energy modeling using Autodesk Revit presents a detailed result of the energy usage and energy flow in the building. The underlying reason of the comparison of three techniques is to understand the simplest, most efficient, accurate method to quantify heat transfer through the building envelope. By the end of this study, the most efficient technique for investigating the building envelope will be expected to be the EnergyPlus technique because of the usage simplicity, ability to take in a lot of details required for simulation and the periodical software updates.

Vapor generation is central to the flow dynamics within fuel injector nozzles. Because the degree of atomization affects engine emissions and spray characteristics, quantification of phase change within diesel fuel injectors is a topic of design interest. Within the nozzle, the large pressure gradient between the upstream and downstream plena induce large velocities, creating separation and further pressure drop at the inlet corner. When local pressure in the throat drops below the fluid vapor pressure, phase change can occur with sufficient time. At the elevated temperatures present in diesel engines, this process can be dependent upon the degree of superheat, motivating the modeling of heat transfer from the wall. By modeling cavitation and flash boiling phenomena as a departure from equilibrium conditions, the HRMFoam model accurately reproduces canonical adiabatic flows. An experimentally determined relaxation time controls the rate at which vapor is generated, and includes model constants tuned for water and a diesel fuel surrogate. The model is shown to perform well for several benchmark experimental cases, including the work of Reitz, Lichtarowicz, and Nurick. With the implementation of the Farve-averaged energy equation, the present work examines and validates the transport of enthalpy through the fixed heat flux and fixed wall temperature boundary conditions. The pipe heat transfer experiments of Boelter and Allen are replicated using the kEpsilon, Realizable kEpsilon, and Spalart-Allmaras models. With proper turbulence model selection, Allen's heat transfer coefficient data is reproduced within 2.9%. Best-case bulk temperature rise prediction is within 0.05%. Boelter's bulk temperature rise is reproduced within 16.7%. Turbulent diffusivity is shown to determine radial enthalpy distribution.

A MATLAB model was developed for the smoldering combustion of wastewater in the context of a decentralized residential wastewater treatment appliance. Data from a batch process sewage smoldering experiment was simulated using implicit finite-difference approximations, assuming one-dimensional transient conductive heat transfer. The time-dependent temperature profiles within the column represented the main parameters of interest and were used to verify recoverable heat energy estimations. Given that the modeling method used for this thesis represents a unique approach, the assumptions and limitations of this model are thoroughly described in the context of reproducing results for other smoldering setups. A lack of convergence is seen in the model validation section of this report. Consequently, the practicality of this particular model contains significant limitations. Theoretical applications are also discussed and analyzed in terms of comparisons to modern alternatives and prototype feasibility.

Fresh water collection techniques have gained significant attention due to global dwindling of fresh water resources and recent scares such as the 2011-2017 California drought. This project explores the economic viability of actively harvesting water from fog, and techniques to maximize water collection. Vapor compression and thermoelectric cooling based dehumidifier prototypes are tested in a series of experiments to assess water collection capability in foggy environments, and what parameters can increase that capability. This testing shows an approximate maximum collection rate of 1.25 L/kWh for the vapor compression prototype, and 0.32 L/kWh for the thermoelectric cooling prototype; compared to 315 L/kWh for desalination or 12 L/m2/day for passive meshes. Exploration of parameters on the thermoelectric cooling prototype show a potential increase in water collection rate of 29% with the addition of a Teflon coating to the collection surface, 15% by clearing the collection surface, and 89% by tilting certain collection surfaces by 60-75°. In combination, these parameters could push active atmospheric water harvesting into economic viability where significant infrastructure investment is not feasible.

The ignition of a solid is an inherently complex phenomenon influenced by heat and mass transport mechanisms that are, even to this day, not understood in entirety. In order to use ignition data in meaningful engineering application, significant simplifications have been made to the theory of ignition. The most common way to classify ignition is the use of material specific parameters such as such as ignition temperature (Tig) and the critical heat flux for ignition (CHF). These parameters are determined through standardized testing of solid materials – however, the results of these tests are generally used in applications different from the environments in which these parameters were actually determined. Generally, ignition temperature and critical heat flux are used as material properties and are presented readily in sources such as the SFPE Handbook. However, these parameters are not truly material properties; each are inherently affected by the environment in which they are tested. Ignition parameters are therefore system dependent, tied to the conditions in which the parameters are determined. Previous work has demonstrated that ignition parameters (such as Tig or CHF) for the same material can vary depending on whether the sample is tested in a vertical or horizontal orientation. While the results are clear, the implications this may have on the use of ignition data remains uncertain. This work outlines the fundamental theory of ignition as well as a review of studies related to orientation. The aim of this study it to analyze the influence of sample orientation on ignition parameters. All experimental work in this study was conducted using cast black polymethyl methacrylate (PMMA or commonly referred to as acrylic). This study explores ignition parameters for PMMA in various orientations and develops a methodology through which orientation can be incorporated into existing ignition theory. An additional study was also conducted to explore the statistical significance of current flammability test methodologies. Ultimately, this study outlines the problem of the system dependency of ignition and provides commentary on the use of ignition data in engineering applications.