The Oxidative Hydrothermal Dissolution (OHD) process was developed at Southern Illinois University to convert solid organic material to low-molecular-weight, water-soluble products using small amounts of dissolved oxygen in liquid water at high temperature and pressure. The process is environmentally friendly; it does not involve the use of solvents or catalysts, and there is little emission of CO2 and no emission of NOx or SOx. Previous studies of the effects of OHD on organic matter have focused on coal, coal waste, and biomass. This study explores the application of OHD to organic-rich shales, providing a baseline investigation into how highly aliphatic materials react under OHD conditions, what types of products are created during the process, whether the products are economically valuable, and whether they provide novel structural and biomarker information that complements typical bulk organic matter characterization methods. Furthermore, typical oil shale utilization methods are plagued by environmental concerns akin, in some respects, to the environmental concerns associated with the coal industry. The successful application of OHD to these materials would provide a cleaner, more efficient way to process oil shale, resulting in an aqueous product that can be transported through pipelines and refined using conventional processing technology. To examine how OHD affects oil shale kerogen, a series of partial conversion experiments were conducted on an Alpha Torbanite sample at varied temperatures, reaction times, and oxidant inputs. Using a fixed-bed type reactor, over 90% carbon conversion was achieved in just 10-12 minutes under relatively mild reaction conditions (300°C) with little gas production, approximately twice as fast as OHD coal conversion. GC-MS analyses of the product distributions for these experiments demonstrate that they do not change significantly under varying reaction conditions, which can be adjusted for maximum carbon conversion. A sample of each type of oil shale (torbanite: Alpha Torbanite, lamosite: Green River Formation, marinite: New Albany Shale, tasmanite: Tasmanian tasmanite, kuckersite: Decorah Formation, cannel: Cannel King) was reacted and analyzed for product distributions. All of the oil shales produced a complex mixture of aliphatic carboxylic acids, dicarboxylic acids, keto-acids, aromatic acids, and poly-acids, some of which include phenolic structures. These products include materials that are useful as chemical feedstocks for the manufacture of plasticizers, nylons, polymers, lubricants, nylons, paints, and a variety of other materials, most of which are currently produced from petroleum derived precursors. Results of OHD biomarker analysis were not comparable to conventional solvent extraction results. With the exception of the Green River sample which did produce favorable results, analyzed steranes and hopanes were not present in measurable/identifiable amounts in the OHD products. It is unclear whether the biomarker peaks are buried under unresolved products or if the biomarkers are oxidizing/degrading under OHD conditions. However, a comparison of OHD product distributions to pyrolysate product distributions demonstrates that this method provides novel information regarding the original macromolecular structure of the kerogen. Since OHD converts a larger fraction of the original carbon, this approach may provide a more complete/correct representation of the initial structure than conventional methods.

AN ABSTRACT OF THE THESIS OF Amberly Hope Tobin, for the Master of Science degree in Organic Geochemistry, presented on August 4th 2016, at Southern Illinois University Carbondale. TITLE: OHD PROCESSING OF COAL WASTE MATERIALS MAJOR PROFESSOR: Dr. Susan M. Rimmer This research addresses coal-waste utilization via the OHD process and the implications for both economic and environmental impacts. The goal of this project is to determine if coal-waste products can be processed by the OHD technique. Furthermore, this project will determine what types of products are produced from the coal-waste materials and will compare these to those produced by the OHD processing of raw coal. This research has the potential to be beneficial to the coal industry as OHD would allow production of high-value products from what is currently viewed as a waste material; additionally, this research will provide a way to recycle what is considered a hazardous waste product and provide an incentive to reclaim coal slurry ponds that are an environmental concern. A preliminary suite of grab samples from an active coal slurry pond along with a stream reject sample were obtained in order to determine if these types of materials could be processed via OHD. After these samples were deemed viable in the OHD process, core samples were taken from a large slurry pond. These cores were then ii sampled at 2 ft (0.61 m) intervals. The key analyses performed were geochemical, petrographic, OHD, and GC-MS. Geochemical analysis included carbon, sulfur, moisture, volatile matter, ash, and fixed carbon content of the coal-waste samples before OHD, and provided a basis for comparison with raw coal samples. Petrographic analysis was performed to determine the maceral composition before the OHD processing. The OHD process is the core technique of this research project. The preliminary slurry pond samples were processed in a small semi-continuous OHD reactor. While the stream reject and slurry pond core samples were processed using a continuous OHD reactor, as this type of reactor is best suited for fine-grained slurries. GC-MS was used to examine the OHD liquid products analysis in order to determine the types of compounds present in the final liquefied product; these products were then compared to raw coal OHD products in order to determine their economic potential. Petrography of the coal-waste materials showed that these samples did contain a notable amount of coal; predominantly vitrinites and inertinites were observed in the samples. Geochemical analysis proved that there were significant amounts of organic carbon in these materials, ranging between 25 and 37%. OHD processing was successful on all coal-waste materials, although the continuous OHD reactor tended to work better with the fine-grained slurries than the semi-continuous OHD reactor. The GC-MS analysis of the coal-waste OHD product showed very similar suites of compounds to that of a bulk coal OHD product; in general, almost all major compounds that are found in a typical coal OHD product were also found in the coal-waste OHD products. This suggests that these slurry ponds, which are typically regarded as waste products, could be viable feedstocks for OHD processing.

Decreased skeletal muscle function (MF) is ubiquitous in hemodialysis (HD) patients and linked to functional decline. Serum vitamin D (25-OHD) and habitual physical activity (PA) are decreased in HD and linked to reduced MF in other populations. The associations between 25-OHD, PA, and MF were investigated in 81 stable HD patients. PA intensity was quantified using accelerometery, MF using handgrip strength dynamometery, 25-OHD via serum measures, and dietary and supplementation of vitamin D intake via three-day food records. MF correlated with PA (r =0.411, p = 0.003) when controlled for body mass (BM) and with 25-OHD (r =0.298, p = 0.023) when controlled for BM, age, and sex. Both MF (r=0.285, p=0.025) and 25-OHD (r=0.314, p=0.005) correlated with vitamin D supplementation. MF remained correlated with supplementation after controlling for 25-OHD (r=0.269, p=0.037). These findings should be further explored in interventional studies to assess how their manipulation influences MF in HD.

Decreased skeletal muscle function (MF) is ubiquitous in hemodialysis (HD) patients and linked to functional decline. Serum vitamin D (25-OHD) and habitual physical activity (PA) are decreased in HD and linked to reduced MF in other populations. The associations between 25-OHD, PA, and MF were investigated in 81 stable HD patients. PA intensity was quantified using accelerometery, MF using handgrip strength dynamometery, 25-OHD via serum measures, and dietary and supplementation of vitamin D intake via three-day food records. MF correlated with PA (r =0.411, p = 0.003) when controlled for body mass (BM) and with 25-OHD (r =0.298, p = 0.023) when controlled for BM, age, and sex. Both MF (r=0.285, p=0.025) and 25-OHD (r=0.314, p=0.005) correlated with vitamin D supplementation. MF remained correlated with supplementation after controlling for 25-OHD (r=0.269, p=0.037). These findings should be further explored in interventional studies to assess how their manipulation influences MF in HD.

In the quest for ultrathin materials compatible with CMOS technology for all-optical signal processing applications in integrated photonics, graphene appears to be a promising candidate, with broadband1 optical properties and a high and broadband optical nonlinearity. However, researchers do not agree on the value of its nonlinear refractive index, and commonly used characterization methods do not provide a clear picture of the optical nonlinearity, in terms of its tensor nature or relaxation time. In the first part of this thesis, apart from the previously used Z-scan method, we have also used the ultrafast Optical Kerr Effect method coupled to Optical Heterodyne Detection (OHD-OKE) for the characterization of the third order optical nonlinearity of monolayer CVD graphene at telecom wavelengths. This method allows to separately measure the real and the imaginary part of the third-order nonlinearity, as well as their dynamics. With respect to the Z-scan method, OHD-OKE presents the major advantage of being robust against inhomogeneities of the sample. As such, we have demonstrated that graphene has a negative nonlinear refractive index, contrary to previously reported results. In addition, we have studied the real and imaginary part of graphene’s nonlinearity, when electrostatic gating is applied to change the chemical potential of graphene. Furthermore, we have proposed an enhanced version of the OHD-OKE method, together with the appropriate theoretical framework, in order to extract the tensor elements of the nonlinearity including the out-of-plane tensor elements. In particular, we have measured separately the time response of the two main tensor elements of the nonlinear susceptibility and we have experimentally verified that the out-of-plane tensor components are negligible. In the second part of this thesis, we have investigated, from an experimental point of view, the use of the nonlinear optical response of graphene for all-optical switching applications in integrated photonics. Namely, we have designed simple silicon nitride waveguide structures that constitute basic building blocks of switching devices, which were then fabricated and covered by graphene patches. Finally, we have experimentally tested the graphene-covered structures at low and high power levels and discussed the results. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished