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This investigation details the effects of fuel constituents on ash deposition through systematic experimental and theoretical analyses of fundamental particle experiments and a suite of fuels with widely varying inorganic contents and compositions. The experiments were carried out in the Multifuel Flow Reactor (MFR) at Brigham Young University. Fuels included several biomass fuels (straw, sawdust and mixtures of straw-sawdust with other additives such as Al(OH)3, CaCO3, etc.) and four commercially-used coals (Illinois#6, Powder River Basin – Caballo and Cordero, Blind Canyon, and Lignite – Beulah Zap). The data from the series of experiments quantitatively illustrate the effects of fuel properties, physical and/or chemical, on ash deposition rate mechanisms. In deposition investigation, the most significant deposition mechanisms in a general ash deposition model – inertial impaction, condensation and eddy impaction – were selected. In this PhD work, these three mechanisms are analyzed using simulation techniques such as Fluent and programming languages such as C++. The experimental data was collected for deposition rate measurements to provide a data set for the model validations except for eddy impaction. In this model analyses, the impaction efficiency model predictions from this work indicated lower impaction efficiencies than the traditional potential flow model presented by others (Israel 1983). The experimental data by others (Lokare 2003) and the data collected in this work support these predictions and present a new impaction efficiency correlation as a function of Stokes number. Similarly, the capture and condensation models perform well and are supported by the respective experimental data. The comprehensive ash deposition model predicts ash deposition rates within 10% of experimental data and is able to distinguish the role of various additives in recipe fuels combustion. As an additional results, NOX behavior of Illinois#6 and PRB (Caballo) in oxyfuel combustion show evidence of inherent NOX reducing feature of oxyfuel combustion.

Estimating the post-mortem interval is important to help identify the deceased in forensic death investigations and requires biogeographically specific knowledge of the rate of decay. Decomposition is influenced by numerous variables, including clothing, climate, and vertebrate scavenging guilds, requiring local studies. Conflicting results have been reported for clothing's effect on decomposition from various international habitats, with no data for Cape Town, South Africa, despite most local forensic cases involving single clothed decedents. Most taphonomic research uses large samples of unclothed human/animal remains to increase statistical reliability, despite this design not simulating common forensic scenarios. This study examined the effect of seasonally appropriate clothing and carrion biomass load on decomposition and scavenging in the thicketed Cape Flats Dune Strandveld, a forensically significant local habitat. Clothing was identified from forensic case files and tailored to ensure an appropriate fit, preventing unrealistic scavenger access. The decay of ten ~60 kg porcine carcasses, as proxies for human decomposition, was quantitatively examined using daily weight loss. This occurred over two consecutive summers and winters between 2018 and 2020, initially comparing clothed versus unclothed carcasses, then examining single clothed carcasses to ascertain the effect of carrion biomass load. On average, double-layer coolweather clothing notably delayed decomposition in winter, but single-layer warm-weather clothing had a comparatively negligible impact in summer. Weight loss correlated with scavenging activity by the Cape grey mongoose (Galerella pulverulenta), which displaced clothing to feed on the abdomen, more so during winter. Scavenging was hindered by the denim trousers, altering feeding patterns and causing preferential scavenging on unclothed carcasses. Single carcasses received more, longer mongoose visits and decomposed quicker than multi-carcass deployments. These results suggest that clothing delays decomposition locally by modulating the effect of seasonal weather and scavenging behaviour. Additionally, research forgoing forensic realism, with large unclothed samples deployed simultaneously, will inadvertently alter the decay rate, creating inaccurate decomposition models for postmortem interval estimation. Future studies should balance statistical robusticity and forensic realism, especially in environments where scavenging is prevalent. Single carcasses clothed in forensically realistic season-specific appropriately tailored clothing should be considered with statistical replication obtained via temporally separated repeat deployments.

Phloem vascular tissues transport sugars synthesized by photosynthesis in mature leaves by a process called phloem loading in source tissues and unloading in sink tissues. Phloem loading in source leaves is catalyzed by Suc/H+ symporters (SUTs) which are energized by proton motive force. In Arabidopsis the principal and perhaps exclusive SUT catalyzing phloem loading is AtSUC2. In mutant plants harboring a T-DNA insertion in each of the functional SUT-family members, only Atsuc2 mutants demonstrate overtly debilitated phloem transport. Analysis of a mutant allele (Atsuc2-4) of AtSUC2 with a T-DNA insertion in the second intron showed severely stunted phenotype similar to previously analyzed Atsuc2 null alleles. However unlike previous alleles Atsuc2-4 produced viable seeds. Analysis of phloem specific promoters showed that promoter expression was regulated by Suc concentration. Unlike AtSUC2p, heterologous promoter CoYMVp was not repressed under high Suc conc. Further analysis was conducted using CoYMVp to test the capacity of diverse clades in SUT-gene family for transferring Suc in planta in Atsuc2 - / - mutant background. AtSUC1 and ZmSUT1 from maize complemented Atsuc2 mutant plants to the highest level compared to all other transporters. Over-expression of the above SUTs in phloem showed enhanced Suc loading and transport, but against expectations, plants were stunted. The implications of SUT over-expression to enhance phloem transport and loading are discussed and how it induces a perception of phosphate imbalance is presented.

Southern Chile is recognized by different international organizations such as UNESCO (United Nations Educational, Scientific and Cultural Organization), and Conservational International as an ecologically sensitive area. The country of Chile is home to one third of the earth’s remaining temperate forests. Monitoring and assessing land cover changes in these forests is important not only to international organizations but to the people of Chile. The lack of multi-temporal studies that evaluate changes in land cover biomass make this study an important one for increasing awareness of how the evolution of the landscape affects environmental planning and development of legal precedents aimed at protecting this rich ecological habitat. The results of this study revealed important differences between the growth and loss of biomass in the period between 1986 and 2003. In the study area, 40% of areas that traditionally supported row crops and pasture hay were replaced my forestry plantations and herbaceous successional vegetation. This replacement has impacted the Chilean people and their agricultural way of life. The results obtained depict the usefulness of Change Vector Analysis (CVA) as a technique to analyze changes in biomass over time.

Production of liquid fuels is a high national priority to provide transporation fuels. Production of liquid biouels from biomass has been idenfied as a viable goal over the next decades. Fast pyrolysis is the rapid thermal degradation of lignocellulosic biomass in the absence of oxygen. Levoglucosan, which can be hydrolyzed and fermented into bio-ethanol, is produced during the pyrolysis process of the cellulose contained in biomass. Pure cellulose results in the production of levoglucosan of more than 50% by feedstock weight while woody biomass typically produces about 3% during pyrolysis. Researchers have performed significant research into methods to increase yields of levoglucosan and other associated anhydrosugars during pyrolysis. Most research has focused on mild acid pretreatment of biomass feedstocks prior to pyrolysis. Such treatment demineralizes and removes hemicellulose that appears to hinder the production of levoglucosan during pyrolysis. The objective of this study is to move beyond simple acid pretreatment to increase pyrolytic anhydrosugars yields during fast pyrolysis.

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No description available.

No description available.