It has long been known that chronic exposures to high concentrations of respirable coal mine dust can lead to the development of lung diseases such as Coal Worker's Pneumoconiosis, commonly referred to as "black lung", and silicosis. Since the mid-1990s, an alarming resurgence of diseases has been documented in central Appalachia, where underground mining often necessitates significant extraction of rock strata along with the thin seams of coal. These circumstances have prompted concern over if or how changing dust composition might be a factor in contemporary disease prevalence. Until now, the total mass concentration and quartz mass fraction of respirable dust have been regulated and monitored in US coal mines. Unfortunately, however, these two metrics alone do not paint a full picture of dust composition. Earlier work in the author's research group established a preliminary thermogravimetric analysis (TGA) method for coal mine dust. The method is intended to allow estimation of three key mass fractions of the dust from separate sources: coal from the coal strata being mined; non-carbonate minerals from the rock strata being mined or drilled; and carbonates that are primarly sourced from application of rock dust products to the mine floor or ribs. However, accuracy of the preliminary method was substantially limited by poor dust recovery from the fibrous filter media used for sample collection. This thesis includes two studies: The first study aims to establish an improved TGA method. It uses smooth polycarbonate (PC) filters for dust sampling and a modified thermal ramping routine. The method is verified using laboratory-generated respirable dust samples. In the second study, the improved TGA method is used to analyze 75 respirable mine dust samples, collected in 15 US mines. Replicate samples are also analyzed by scanning electron microscopy using energy dispersive X-ray (SEM-EDX). TGA and SEM-EDX results are compared to gain insights regarding the analytical methods and general trends in dust composition within and between mines. / Master of Science / It has long been known that chronic exposures to excessive respirable coal mine dust can lead to the development of lung diseases such as Coal Worker’s Pneumoconiosis (“Black Lung”) and silicosis. Disease rates in central Appalachia have shown an alarming and unexpected increase since the mid-1990s, despite declining dust concentrations evident from regulatory compliance monitoring data. Clearly, there is a need to better understand coal mine dust composition, which will require additional analytical methods. Thermogravimetric analysis (TGA) has been proposed as one possible method, because it should allow estimation of three key dust components from separate sources: coal from the coal strata being mined; non-carbonate minerals from the rock strata being mined or drilled; and carbonates from application of rock dust products to the mine floor and ribs. However, preliminary work with TGA showed limited accuracy, mostly due to sampling materials. In this thesis, two studies were performed. The first study aims to establish an improved TGA method using smooth, polycarbonate (PC) filters. The second study demonstrates the method on a large number of mine dust samples, and compares the results to those gained by an alternative method that uses electron microscopy.

Inhalation of respirable dust in coal mines is a serious occupational health hazard which can lead to the development of chronic and irreversible lung diseases, such as Coal Worker's Pneumoconiosis (CWP) and Progressive Massive fibrosis (PMF). After the passage of the Federal Coal Mine Health and Safety Act (CMHSA) in the late 1960's the prevalence of CWP among US coal miners decreased. However, since the late 1990's a resurgence of lung diseases has been reported, particularly in central Appalachia. On the other hand, dust monitoring data suggest that concentrations of respirable coal mine dust (RCMD) and crystalline silica have been on a downward trend. This contradiction has prompted keen interest in detailed characterization of RCMD to shed light on dust constituents-and their sources. Such information might help miners understand where and under what conditions specific sources contribute to RCMD, and how dust controls and monitoring could be enhanced to mitigate the exposure to respirable hazards. Respirable dust particles generated in coal mines are generally associated with three primary sources: the coal strata that is mined and generates mostly coal particles that could contribute for lung diseases, the rock strata that is cut along with the coal and generates most of the respirable silica and silicates, and the rock dust products that are the main source of carbonates which could produce respiratory irritations. Thermogravimetric Analysis (TGA) is one of many analytical tools that might be used for dust characterization. Its primary benefit is that it can be used to apportion the total sample mass into three mass fractions (i.e., coal, carbonates, non-carbonates) which should be roughly associated with the primary dust sources (i.e., coal strata, rock dust products, rock strata) in many coal mines. This thesis consists of two main chapters: Chapter 1, outlines the research motivation, recaps the efforts to establish a standard TGA method for RCMD, and shows results of the validation experiments that were performed in the current work to enable application of the TGA method to a large set of RCMD and laboratory-generated dust samples. In Chapter 2, 46 lab-generated samples from primary dust source materials collected in 15 coal mines, and 129 respirable dust samples from 23 US coal mines are analyzed using the TGA method validated in Chapter 1. Results for both sets of samples are presented and the mine samples are interpreted based on sampling location, mining method and region. Additionally, Chapter 3 summarizes recommendations for future work. / Master of Science / The chronic exposure to dust generated in underground coal operations represents a serious health concern among coal miners that can lead to the development of lung diseases such as Coal Workers Pneumoconiosis (CWP or "black lung). Despite of dust compliance monitoring data that have shown that the concentrations of dust have been declining, since the late 1990's the number of US coal miners diagnosed with lung diseases has been increasing, especially in central Appalachia. This contradiction has prompted keen interest in detailed characterization of respirable coal mine dust (RCMD) to shed light on dust constituents-and their sources. Such information might help miners understand where and under what conditions specific sources contribute to RCMD, and how dust controls and monitoring could be enhanced to mitigate the exposure to respirable hazards. Thermogravimetric Analysis (TGA) has been proposed as an alternative approach for dust characterization. Its primary benefit is that it can be used to apportion the total sample mass into three mass fractions (i.e., coal, carbonates, non-carbonates) which should be roughly associated with the primary dust sources (i.e., coal strata, rock dust products, rock strata) in many coal mines. This thesis consists of two main chapters: Chapter 1, outlines the research motivation, recaps the efforts to establish a standard TGA method for RCMD, and shows results of the validation experiments that were performed in the current work to enable application of the TGA method to a large set of RCMD and laboratory-generated dust samples. In Chapter 2, 46 lab-generated samples from primary dust source materials collected in 15 coal mines, and 129 respirable dust samples from 23 US coal mines are analyzed using the TGA method validated in Chapter 1. Results for both sets of samples are presented and the mine samples are interpreted based on sampling location, mining method and region. Additionally, Chapter 3 summarizes recommendations for future work.

For the first time, a novel processing method of co-refining wood and polyolefin (PO) by steam-explosion was scientifically explored for wood-thermoplastic composites without a coupling agent. Traditional studies have addressed the improvement of adhesion between components of wood thermoplastic composites through the use of coupling agents such as maleated PO. The objective of this study was to increase adhesion between wood and PO through reactive processing conditions of steam-explosion. PO characteristics, such as type (polyethylene or polypropylene), form (pellet, fiber, or powder) and melt viscosity were studied along with oxygen gas content of the steam-explosion reactor vessel. Modification of co-processed wood fiber was characterized in four studies: microscopy analysis of dispersion of PO with wood fiber, sorption properties of co-processed material, chemical analysis of fractionated components, and morphological investigation of co-processed material. Two additional studies are listed in the appendices that relate to adsorption of amphiphilic polymers to the cellulose fiber surface, which is one hypothesis of fiber surface modification by co-steam-explosion. Microscopy studies revealed that PO melt viscosity was found to influence the degree of dispersion and uniformity of the steam-exploded material. The hygroscopic nature of the co-processed fiber declined as shown by sorption isotherm data. Furthermore, a water vapor kinetics study found that all co-refined material had increased initial diffusion coefficients compared to the control fiber. Chemical changes in fractionated components were PO-type dependent. Lignin extracted from co-processed wood and polyethylene showed PO enrichment determined from an increase of methylene stretching in the Fourier Transform infrared subtraction spectra, while lignin from co-processed wood and polypropylene did not. Additionally, extracted PO showed indirect signs of oxidation as reflected by fluorescence studies. Solid state nuclear magnetic resonance spectroscopy revealed a number of differences in the co-processed materials such as increased cellulose crystallinity, new covalent linkages and an alternative distribution of components on the nanoscale reflected in the T1Ï relaxation parameter. Steam-explosion was shown to modify wood fiber through the addition of "non-reactive" polyolefins without the need for coupling agents. In light of these findings, co-refining by steam-explosion should be viewed as a new reactive processing method for wood thermoplastic composites. / Ph. D.

A interação da água com a celulose e com o amido é de grande importância para a compreensão das propriedades de ambos polissacarídeos e fundamental para o desenvolvimento de novas aplicações tecnológicas. Entre as novas aplicações estão em destaque a nanocelulose, como os nanocristais e microfibrilas. A preparação desses materiais é fortemente influenciada pela interação das ligações de hidrogênio presente nas fibras de celulose, tanto de caráter intra como intermolecular. Essas interações são responsáveis pelas propriedades mecânicas desses materiais uma vez que as moléculas estão ligadas umas às outras por meio de ligações de hidrogênio onde a água pode participar como elemento de ligação. Para o amido, dependendo da concentração da água, pode modifica-lo em termos da solubilidade e em propriedades pelo processo de gelatinização ou atuar como plastificantes como parcial despolimerização em amido termoplástico. Neste trabalho é descrito o estudo da interação do sistema água com a celulose e com o sistema água com amido por meio da análise termogravimétrica para a identificação de diferentes espécies de água: i) água livre, ii) água ligada congelável iii) água ligada não congelável. Para a realização deste estudo foi utilizado o método auto stepwise, método que permite uma maior resolução dos diversos fenômenos separadamente que ocorrem durante a dessorção da água. A dessorção da água no amido se demostrou mais complexa que a celulose devido à alternância da parte amorfa e cristalina em sua estrutura. Para o cálculo da energia de ativação da dessorção da água ligada e da degradação do polissacarídeo foi utilizado o método cinético de Osawa-Flynn-Wall, sendo possível estimar a energia de ativação dos fenômenos. Variando de 35-65 kJ/mol para dessorção da água ligada e 144,6-184 kJ/mol para degradação dos materiais. / The interaction of water with cellulose and starch are of great importance for understanding the properties of both polysaccharides and fundamental to the development of new technological applications. Among the new applications are highlighted to nanocellulose such as nanocrystals and microfibrils. The preparation of these materials is strongly influenced by the interaction of hydrogen bonds present in the cellulose fibers, both intra as intermolecular. These interactions are responsible for the mechanical properties of these materials since the molecules are linked to each other through hydrogen bonds where water can participate as a connecting element. For starch, depending on the concentration of the water, can modify it in terms of solubility and properties by gelatinization process or act as plasticizers as partial depolymerization of thermoplastic starch. This paper describes the study of the interaction of the water/cellulose system and the starch/water system by means of thermogravimetric analysis for the identification of different species of water: i) the free water or freezing water, ii) the freezing bound water and iii) the non-freezing bound water. For this study we used the auto stepwise method, that allows greater resolution of the various phenomena separately that occur during the water desorption. The water desorption in the starch is more complex that cellulose, due to alternating crystalline and amorphous parts of the structure. To calculate the bound water desorption activation energy and polysaccharide degradation energy was used kinetic method of Osawa-Flynn-Wall, that possible to estimate the phenomena of the activation energy, ranging from 35-65 kJ / mol for bound water desorption and from 144.6 to 184 kJ / mol for material degradation.

Lime has been used in construction for millennia, and its value, especially in the field of conservation architecture, has only recently been rediscovered. Lime mortars harden through carbonation, and this thesis is a study of that process. The research conducted has resulted in the development of two novel techniques for the measurement and detection of carbonation. The first technique is a method of thermogravimetric analysis which allows the carbonation profile to be measured within an acceptable time-frame. The second technique is the use of drilling resistance measurement to visualise the carbonation profile. The potential of elemental analysis to measure the carbonation profile has also been identified. It has been demonstrated that the lime/water ratio has less impact on the compressive strength of air lime mortars than had previously been supposed. The change in the pore size distribution of air lime mortars caused by carbonation has been studied, and a theory has been proposed to explain this phenomenon. Five different forms of air lime binder were studied. The impact of these on the structural performance of the resultant mortars has been assessed. It was concluded that mortars made with lime putties perform better than mortars made with dry lime hydrate. Mortars made with dispersed hydrated lime appear to perform as well as mortars made with lime putties, but at a slower rate of strength growth. The use of extra mature lime putty does not appear to confer structural performance benefits when compared with ordinary lime putty. It has been shown that the use of calcitic aggregates can produce air lime mortars which perform as well as moderately hydraulic lime mortars. It is theorised that this phenomenon is not directly related to carbonation, but rather to a complex interaction of the granulometry, mineralogy, chemistry and porosity of the aggregate with the binder.

Biodegradable, edible wheat gluten films offer a renewable alternative to plastic food packaging or can be incorporated directly in the food product. Wheat gluten is a good option because it forms a fibrous network, lending strength and elasticity to films. The goal of this research project was to produce, with a water-based film formulation and methodology, smooth, homogeneous wheat gluten films with low water vapour permeability (WVP). The water-based film formulation also served to compare the FT Wonder wheat cultivar, grown in Ontario, to commercially produced wheat gluten and determine the effect of wheat source on the film properties, surface morphology, surface hydrophobicity, WVP, and film swelling in water for different pH, temperature and casting surface conditions. Fluorescence, SPR, and casting formulation viscosity provided preliminary information on the mechanism of film formation and on gluten protein structure induced by modifying the film formulation. This research provides an alternate use for some Ontario wheat cultivars based on their properties in films compared to commercial sources of gluten. As a result, using Ontario cultivars to prepare gluten film packaging material has potential as an alternate source of income for Ontario farmers. This research also defines the film properties for gluten films produced from aqueous solutions, helping to identify processing parameters that could bring gluten films on par with plastic packaging and make gluten films a viable alternative food packaging material. Finally, it was determined that the water vapour permeability of wheat gluten films was not correlated to film surface contact angle.

The objective of this study is to investigate the influence of sulfur compounds (S and Na2S) for powdered activated carbon derived from carbon black of pyrolyzed waste tires (CPBAC). Besides, this study investigated the distribution of impregnated sulfur in the inner pores of activated carbon and its effected on the specific surface area and pore size distribution. This study investigated the fundamental mechanisms by analysis of thermodynamic properties and to establish the kinetic models for the adsorption/desorption of HgCl2 by/from sulfur impregnated CBPAC. Furthermore, this study investigated the adsorptive and desorption capacity of HgCl2 onto CPBAC via thermogravimetric analysis (TGA). Experimental results indicated that the specific surface area of sulfur impregnated CBPAC with elemental S (S0) was larger than sulfur impregnated CBPAC with Na2S. Besides, the sulfur content of sulfur impregnated CBPAC increased with increasing the surface area of CBPAC under the same impregnated temperature. And, the adsorptive capacity of CBPAC increased with the increase of influent HgCl2 concentration and surface area of the activated carbon. According to the experimental results of the adsorption capacity under the differential sulfur content, its indicated that the affection of sulfur content for adsorption capacity of HgCl2 was much than HgCl2 concentration and surface area of the activated carbon. The desorption energys were 266 and 282 kJ/mole for HgCl2 desorption from saturated CBPAC-S0 and CBPAC-Na2S, respectively. The results showed the process of HgCl2 adsorption onto CBPAC was in favor of a physisorbed state of HgCl2 at the adsorption temperature of 150 oC but the process of HgCl2 adsorption onto CBPAC which impregated was in favor of a chemisorbed state of HgCl2 at the adsorption of 150 oC. The value of ∆G for CBPAC at the adsorption temperature of 30 ~150 oC were ranged from -15.28 kJ/mole to -26.63 kJ/mole. The value of ∆G for CBPAC-S0 at the adsorption temperature of 30~150 oC ranged from -23.45 kJ/mole to -32.09 kJ/mole. The value of ∆G for CBPAC-Na2S at the adsorption temperature of 30~150 oC ranged from -22.84 kJ/mole to -32.72 kJ/mole. The results showed negative values of ∆G confirmed the feasibility of adsorption process and the spontaneous nature for the adsorption of HgCl2. The value of ∆H for CBPAC at the adsorption temperature of 30 ~150 oC ranged from -35.58 kJ/mole to -35.82 kJ/mole. The value of ∆H for CBPAC-S0 at the adsorption temperature of 30 ~150 oC ranged from -38.07 kJ/mole to -52.49 kJ/mole. The value of ∆H for CBPAC-Na2S at the adsorption temperature of 30~150 oC was -37.45 kJ/mole to -53.12 kJ/mole. A negative ∆H suggested that the adsorption of HgCl2 is an exothermic process. Besides, the adsorptive behavior of HgCl2 for two activated carbons (CBPAC-Na2S and CBPAC-S0) at high temperature (110 ¢J and 150 ¢J ) was the same chemical reaction mechanism due to the same ∆H. Besides, the results of model simulation indicated that modified adsorption kinetic model based on pore diffusion scheme developed in this study could successfully simulate the transport and adsorption of HgCl2 by considering the chemical reaction within the inner pores of carbon grains at 150 oC.

The past few years have seen an upsurge in the use of renewable biomass as a source of energy due to growing concerns over greenhouse gas emissions caused by the combustion of fossil fuels and the need for energy independence due to depleting fossil fuel resources. Although coal will continue to be a major source of energy for many years, there is still great interest in replacing part of the coal used in energy generation with renewable biomass. Combustion converts inherent chemical energy of carbonaceous feedstock to only thermal energy. On the other hand, partial oxidation processes like gasification convert chemical energy into thermal energy as well as synthesis gas which can be easily stored or transported using existing infrastructure for downstream chemical conversion to higher value specialty chemicals as well as production of heat, hydrogen, and power. Devolatilization or pyrolysis plays an important role during gasification and is considered to be the starting point for all heterogeneous gasification reactions. Pyrolysis kinetic modeling is, therefore, an important step in analyzing interactions between blended feedstocks. The thermal evolution profiles of different coal-biomass blends were investigated at various heating rates using thermogravimetric analysis. Using MATLAB, complex models for devolatilization of the blends were solved for obtaining and predicting the global kinetic parameters. Parallel first order reactions model, distributed activation energy model and matrix inversion algorithm were utilized and compared for this purpose. Using these global kinetic parameters, devolatilization rates of unknown fuel blends gasified at unknown heating rates can be accurately predicted using the matrix inversion method. A unique laboratory scale auto-thermal moving bed gasifier was also designed and constructed for studying the thermochemical conversion of coal-biomass blends. The effect of varying operating parameters was analyzed for optimizing syngas production. In addition, stable carbon isotope analysis using Gas Chromatography-Combustion-Isotope Ratio Mass Spectrometry (GC-C-IRMS) was used for qualitatively and quantitatively measuring individual contributions of coal and biomass feedstocks for generation of carbonaceous gases during gasification. The predictive models utilized and experimental data obtained via these methods can provide valuable information for analyzing synergistic interactions between feedstocks and also for process modeling and optimization.

Biodegradable, edible wheat gluten films offer a renewable alternative to plastic food packaging or can be incorporated directly in the food product. Wheat gluten is a good option because it forms a fibrous network, lending strength and elasticity to films. The goal of this research project was to produce, with a water-based film formulation and methodology, smooth, homogeneous wheat gluten films with low water vapour permeability (WVP). The water-based film formulation also served to compare the FT Wonder wheat cultivar, grown in Ontario, to commercially produced wheat gluten and determine the effect of wheat source on the film properties, surface morphology, surface hydrophobicity, WVP, and film swelling in water for different pH, temperature and casting surface conditions. Fluorescence, SPR, and casting formulation viscosity provided preliminary information on the mechanism of film formation and on gluten protein structure induced by modifying the film formulation. This research provides an alternate use for some Ontario wheat cultivars based on their properties in films compared to commercial sources of gluten. As a result, using Ontario cultivars to prepare gluten film packaging material has potential as an alternate source of income for Ontario farmers. This research also defines the film properties for gluten films produced from aqueous solutions, helping to identify processing parameters that could bring gluten films on par with plastic packaging and make gluten films a viable alternative food packaging material. Finally, it was determined that the water vapour permeability of wheat gluten films was not correlated to film surface contact angle.

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Estima-se que 40-60% do volume processado seja considerado rejeito. Uma alternativa de aproveitamento da biomassa residual é a sua utilização para a obtenção de energia a partir do processo de pirólise. A compreensão desse processo envolve o estudo da cinética de degradação da biomassa residual, dos fenômenos de transporte, bem como do tipo, configuração e condições ótimas de operação do reator. O objetivo principal deste trabalho é o estudo cinético da pirólise de bagaço de laranja. Com relação à análise termogravimétrica, esta foi avaliada em dois estágios: o primeiro referente à perda de água livre até 373 K (secagem) e o segundo referente às reações de pirólise (devolatilização). Para a fase de secagem, modelos semi-empíricos de secagem foram usados em suas formas não isotérmicas. Já para a fase de devolatilização, utilizaram-se os modelos isoconversionais e o das reações paralelas independentes (RPI) reparametrizado. Para o primeiro estágio, o modelo que melhor descreveu a etapa de secagem dinâmica foi o de Overhutz, obtendo-se energia de ativação média de 11,24 kJ/mol. Já para o segundo estágio, os modelos isoconversionais apresentaram energia de ativação entre 104,94 e 417,27 kJ/mol. O modelo de Reações Paralelas Independentes Reparametrizado apresentou energia de ativação entre 130,32 e 153,62 kJ/mol, 144,00 e 194,65 kJ/mol, 59,23 e 85,41 kJ/mol, 74,16 e 148,89 kJ/mol, e 163,95 e 184,23 k/mol para hemicelulose, celulose, lignina, pectina e componente não conhecido, respectivamente. As frações dos subcomponentes do bagaço de laranja também foram estimados e obtiveram-se valores aproximados de 21, 31, 17, 25 e 6% de hemicelulose, celulose, lignina, pectina e componente x, respectivamente. Além disso, avaliou-se a cinética de secagem convectiva do bagaço, visto que o mesmo possui uma alta umidade inicial, empregando-se as equações semi-empíricas de cinética de secagem. A energia de ativação para a cinética convectiva do bagaço de laranja foi de 20,99 kJ/mol e o modelo de Overhultz foi o que melhor se adequou aos dados experimentais. / Brazil produces 1.4 million tons of orange juice, accounting for 50% of world production. It is estimated that 40-60% of the volume processed is considered tailings. An alternative use of residual biomass is their use for obtaining energy from the pyrolysis process. Understanding this process involves the study of the residual biomass degradation kinetics, transport phenomena, and the type, configuration, and optimal conditions of reactor operation. The aim of this work is the kinetic study of orange bagasse pyrolysis. With respect to thermogravimetric analysis, this was assessed in two stages: the first refers to the free water loss to 373 K (drying) and the second referring to the pyrolysis reactions (devolatilization). For the drying step, the semi-empirical models of drying were used in their non-isothermal forms. As for the devolatilization phase, they used the isoconversionais models and independent parallel reactions (RPI) reparametrized. For the first stage, the model that best describes the dynamic drying step was to Overhutz, obtaining average activation energy of 11,24 kJ/mol. As for the second stage, isoconversionais models showed activation energy between 104,94 and 417,27 kJ/mol. The reparametrized Independent Parallel Reactions model presented activation energy between 130,32 and 153,62 kJ/mol, 144,00 and 194,65 kJ/mol, 59,23 and 85,41 kJ/mol, 74,16 and 148,89 kJ/mol, and 163,95 and 184,23 kJ/mol for hemicellulose, cellulose, lignin, pectin, and component not known respectively. Fractions of subcomponents of orange bagasse were also estimated and is obtained approximate values of 21, 31, 17, 25 and 6% hemicellulose, cellulose, lignin, pectin and component x, respectively. In addition, it evaluated the convective drying kinetics bagasse, since it has a high initial moisture content, using the semi-empirical equations drying kinetics. The activation energy for convective kinetics of orange bagasse was 20,99 kJ/mol and the Overhultz model was the one best suited to the experimental data.