Wildland fire, which includes both planned (prescribed fire) and unplanned (wildfire) fires, is an important component of many ecosystems. Prescribed burning (controlled burning) is used as an effective tool in managing a variety of ecosystems in the United States to reduce accumulation of hazardous fuels, manage wildlife habitats, mimic natural fire occurrence, manage traditional native foods, and provide other ecological and societal benefits. During wildland fires, both live and dead (biomass) plants undergo a two-step thermal degradation process (pyrolysis and combustion) when exposed to high temperatures. Pyrolysis is the thermal decomposition of organic material, which does not require the presence of oxygen. Pyrolysis products may later react with oxygen at high temperatures, and form flames in the presence of an ignition source. In order to improve prescribed fire application, accomplish desired fire effects, and limit potential runaway fires, an improved understanding of the fundamental processes related to the pyrolysis and ignition of heterogeneous fuel beds of live and dead plants is needed.In this research, fast pyrolysis of 14 plant species native to the forests of the southern United States has been studied using a flat-flame burner (FFB) apparatus. The results of fast pyrolysis experiments were then compared to the results of slow pyrolysis experiments. The plant species were selected, which represent a range of common plants in the region where the prescribed burning has been performed. The fast pyrolysis experiments were performed on both live and dead (biomass) plants using three heating modes: (1) convection-only, where the FFB apparatus was operated at a high heating rate of 180 °C s-1 (convective heat flux of 100 kW m-2) and a maximum fuel surface temperature of 750 °C; (2) radiation-only, where the plants were pyrolyzed under a moderate heating rate of 4 °C s-1 (radiative heat flux of 50 kW m-2), and (3) a combination of radiation and convection, where the plants were exposed to both convective and radiative heat transfer mechanisms. During the experiments, pyrolysis products were collected and analyzed using a gas chromatograph equipped with a mass spectrometer (GC-MS) for the analysis of tars and a gas chromatograph equipped with a thermal conductivity detector (GC-TCD) for the analysis of light gases.The results showed that pyrolysis temperature, heating rate, and fuel type, have significant impacts on the yields and the compositions of pyrolysis products. These experiments were part of a large project to determine heat release rates and model reactions that occur during slow and fast pyrolysis of live and dead vegetation. Understanding the reactions that occur during pyrolysis then can be used to develop more accurate models, improve the prediction of the conditions of prescribed burning, and improve the prediction of fire propagation.

Biomass pyrolysis and gasification techniques count among basic technological procedures for its use as a source of energy. As a side-effect, production of tar can be considered. Tar is a complex mixture of various organic compounds and affects negatively both the environment and the facilities where biomass is processed. Within the scope of this master thesis the analysis of tar samples from different materials was performed. As an appropriate analytical method the gas chromatography combined with flame ionization detection (GC-FID) and time-of-flight mass spectrometry (GC-TOF-MS) was chosen. The concentrations of volatile organic compounds known as BTEX, polycyclic aromatic hydrocarbons (PAH) and phenolic compounds were assessed.

Biomass is a renewable source of energy and represents an acceptable alternative to fosil fuels. Usable methods of energetic use of biomass are combustion and gasification. Main interest is focused on gasification in last years. Gasification is based on conversion of organic material to usable gaseous product called syngas, which can be used as a fuel for energy production. Large amount of tar is formed as a by-product of incineration and gasification of biomass. Tar is composed by various mixture of organic substances, has a negative effect on operating conditions and is a potential threat to environment. Experimental part of this study was focused on analysis of tar obtained by gasification of various kind of biomass. Selected groups of hydrocarbons and oxygen compounds were identified in analysed samples. Individual biomass samples were compared regarding to determined relative content of selected substances. Analysis was done by complete twodimensional gas chromatography with mass spectrometric detection (GCxGC/TOF-MS).

<p>  </p> <p>Tar spot is a new foliar disease of corn in the United States. Tar spot was first detected in 2015 and is now among the most important corn diseases in the Midwest. Tar spot is caused by the obligate biotrophic fungus, <em>Phyllachora maydis</em> Maubl, from the genus, <em>Phyllachora </em>which consist of over 1,200 species of host-specific fungi. Due to the recent emergence, studies relating to <em>P. maydis</em> population dynamics in the U.S. are limited. How much genetic diversity, variation, and level of gene flow are occurring within and among these populations? Knowledge of the population dynamics is imperative for understanding the pathogen’s biology, ecology, epidemiology, and management. Currently, no corn hybrid is fully resistant to tar spot. Foliar fungicides are currently the most effective option for disease management, but best practices for fungicide management remain unknown. Better information is needed on fungicide efficacy and fungicide application timing to reduce tar spot severity, protect yield, and increase profitability for Indiana corn growers. </p> <p>This research dissertation presents four chapters to answers those questions and bridge the gaps between the knowns and unknows of this novel corn-<em>Phyllachora maydis</em> pathosystem. <strong>Chapter 1</strong> presents a literature review on tar spot of corn, its economic impact, the causal pathogen, its host, lifecycle, distribution, and known management strategies as a resource for understanding the pathosystem in the U.S. <strong>Chapter 2</strong> examines the genetic population structure, diversity, geneflow and mode of reproduction in Midwest U.S. by employing microsatellite (SSR) markers. <strong>Chapter 3</strong> presents results from multi-year, multi-location, small-plot field trials on the net return of foliar fungicides and fungicide timing on tar spot management in Indiana. Lastly, <strong>Chapter 4</strong> concludes by evaluating of an integrated management strategy for tar spot by examining the integration of tillage, corn hybrids and fungicide application in reducing tar spot severity while protecting yields.</p> <p>Results provided in this research dissertation will be used to guide future studies and provide stakeholders such as researchers, corn growers, extension personnel in academia and industry with valuable information needed to guide effective disease management decisions. </p>

Prescribed (i.e., controlled) burning is a common practice used in many vegetation types in the world to accomplish a wide range of land management objectives including wildfire risk reduction, wildlife habitat improvement, forest regeneration, and land clearing. To properly apply controlled fire and reduce unwanted fire behavior, an improved understanding of fundamental processes related to combustion of live and dead vegetation is needed. Since the combustion process starts with pyrolysis, there is a need for more data and better models of pyrolysis of live and dead fuels. In this study, slow pyrolysis experiments were carried out in a pyrolyzer apparatus and a Thermogravimetric analyzer (TGA) under oxygen free environment in three groups of experiments. In the first group, the effects of temperature (400–800 °C), a slow heating rate (H.R.) (5–30 °C min−1), and carrier gas flow rate (50–350 ml min−1) on yields of tar and light gas obtained from pyrolysis of dead longleaf pine litter in the pyrolyzer apparatus were investigated to find the optimum condition which results in the maximum tar yield. In the second group of experiments, 14 plant species (live and dead) native to forests in the southern United States, were heated in the pyrolyzer apparatus at the optimum condition. A gas chromatograph equipped with a mass spectrometer (GC–MS) and a gas chromatograph equipped with a thermal conductivity detector (GC-TCD) were used to study the speciation of tar and light gases, respectively. In the third group of experiments, the slow pyrolysis experiments for all plant species (live and dead) were carried out in the TGA at 5 different heating rates ranged from 10 to 30 ℃ min-1 to study the kinetics of pyrolysis. The results showed that the highest tar yield was obtained at a temperature of 500 °C, heating rate of 30 °C min−1, and sweep gas flow rate of 100 ml min−1. In addition, the tar composition is dominated by oxygenated aromatic compounds consisting mainly of phenols. The light gas analysis showed that CO and CO2 were the dominant light gas species for all plant samples on a dry wt% basis, followed by CH4 and H2. The kinetics of pyrolysis was studied using one model-free method and three model-fitting methods. First, the model-free method of Kissinger-Akahira-Sunose (KAS) was used to calculate the rates of pyrolysis as a function of the extent of conversion. The results showed that different plant species had different rates at different conversions. Then, three model fitting methods were used to find the kinetic parameters to potentially provide a single rate for each plant species. The results showed that the simple one-step model did not fit the one-peak pyrolysis data as well as the distributed activation energy model (DAEM) model. The multiple-reaction DAEM model provided very good fits to the experimental data where multiple peaks were observed, even at different heating rates.

Tato práce studovala vliv použití vzduchu a páry jako zplynovacího činidla ve zkapalňovacím generátoru plynu na vlastnosti vyprodukovaného plynu (oxid uhelnatý, vodík, obsah dehtu a nízká výhřevnost). Tato studie byla založena na experimentech které byly provedeny ve fluidním generátoru plynu Biofluid 100 v laboratoři Energetického ústavu technologické univerzity Brno s použitím páry jako zplynovacího činidla a borovicového dřeva jako výchozí suroviny. Cílem této dizertační práce je stanovit nejlepší provozní parametry systému při užití vodní páry a vzduchu ve zplynovacím zařízení biofluid 100, při kterých se dosáhne nejvyšší kvality plynu. K dosažení tohoto cíle bylo provedeno mnoho experimentů studujících účinky teploty reaktoru(T101), poměru páry a biomasy (S/B) poměru páry a vzduchu (S/A), teploty dodávané páry (Tf1), ekvivalentního poměru ER,ve složení vyprodukovaném plynu, výhřevnost, výtěžnost plynu, efektivnost přeměny uhlíku a účinnost zplynovače. Výsledky experimentů ukázaly, že zvýšení teploty reaktoru vede ke zvýšení obsahu vodíku a oxidu uhelnatého, výhřevnosti, výtěžnosti plynu, efektivnosti přeměny uhlíku, efektivnosti zplynovače a ke snížení obsahu dehtu. Příliš vysoká teplota reaktoru ale snižuje výhřevnost plynu. Dodáváním páry se zvýšila kvalita plynu, vyšší H_2,LHV a nižší obsah dehtu. Přesto ale nadměrné množství páry snižuje zplyňovací teplotu a tím i kvalitu plynu. Poměr páry a biomasy při kterém se dosáhne nejlepší kvality plynu se zvýší s teplotou reaktoru. Bylo zjištěno, že kdykoli byla teplota páry (Tf1) vyšší, byl plyn více kvalitní, ale zvyšování teploty páry také zvyšuje ekonomické náklady na vyprodukovaný plyn což se při masové produkci plynu musí brát v úvahu. Efekt ekvivalentního poměru ER, byl studován postupným zvyšováním, bylo zjištěno, že nejlepší ekvivalentní poměr pro dosažení nejvyšší kvality plynu byl kolem 0.29, při ER > 0.29 byl obsah hořlavého plynu snížen a to vedlo ke snížení kvality plynu. Obsah dehtu se snižuje jak zvýšením teploty reaktoru tak poměrem páry k biomase. Podle výsledků experimentů a diskuze, bylo zjištěno, že při použití směsi páry a vzduchu se kvalita plynu zvýší, parametry pro dosažení nejvyšší kvality vyprodukovaného plynu při experimentálních podmínkách jsou: T101 =829 S/B=0.67((kg steam)/(kg biomass)) ,S/A=0.67((kg steam)/(kg air)) , ER= 0.29 and a Tf1 je nejvyšší možná teplota,při které se vodík zvýší z 10.48 na 19,68% a výhřevnost z 3.99 na 5.52(MJ/m^3 ) a obsah dehtu z 1964(mg/m^3 ) na 1046(mg/m^3 ) zvýšením z 0 na 0.67 při T101=829 .

Indiana University-Purdue University Indianapolis (IUPUI) / The sailors in the British Navy during the Napoleonic Wars are largely unknown to us. This thesis explores their worldview, as revealed through songs, memoirs, plays and broadsides. Through interactions with women and working-class men on shore and officers at sea, these men developed a collective identity rooted in working class masculinity. Ultimately, this thesis refutes the idea that sailors occupied a world completely removed from land and were, rather, actively influenced by ideologies and culture on shore.

In this study, we present two new frequency domain tests for testing the Gaussianity and linearity of a sixth-order stationary univariate time series. Both are two-stage tests. The first stage is a test for the Gaussianity of the series. Under Gaussianity, the estimated normalized bispectrum has an asymptotic chi-square distribution with two degrees of freedom. If Gaussianity is rejected, the test proceeds to the second stage, which tests for linearity. Under linearity, with non-Gaussian errors, the estimated normalized bispectrum has an asymptotic non-central chi-square distribution with two degrees of freedom and constant noncentrality parameter. If the process is nonlinear, the noncentrality parameter is nonconstant. At each stage, empirical distribution function (EDF) goodness-ofit (GOF) techniques are applied to the estimated normalized bispectrum by comparing the empirical CDF with the appropriate null asymptotic distribution. The two specific methods investigated are the Anderson-Darling and Cramer-von Mises tests. Under Gaussianity, the distribution is completely specified, and application is straight forward. However, if Gaussianity is rejected, the proposed application of the EDF tests involves a transformation to normality. The performance of the tests and a comparison of the EDF tests to existing time and frequency domain tests are investigated under a variety of circumstances through simulation. For illustration, the tests are applied to a number of data sets popular in the time series literature.

RNAs have gained significant attention in recent years because they can fold into well-defined secondary or tertiary structures. These three dimensional architectures provide interfaces for specific RNA-RNA or RNA-protein interactions that are essential for biological processes in a living system. These discoveries greatly increased interest in RNA as a potential drug target for the treatment of diseases. Two of the most studied RNA based regulatory systems are HIV-1 trans-activating response element (TAR)/Tat replication pathway and Rev response element (RRE)/Rev export pathway. To efficiently target TAR and RRE RNA, we designed and synthesized three generations of branched peptide libraries that resulted in medium sized molecules. The first generation of BPs were discovered from screening a one-bead one-compound library (4,096 compounds) against HIV-1 TAR RNA. One peptide FL4 displayed a binding affinity of 600 nM to TAR RNA, which is tighter than its native protein counterpart, Tat. Biophysical characterization of these BP demonstrated that "branches" in BPs impart multivalency, and they are cell permeable and non-toxic. The second generation peptides were discovered from an on-bead high-throughput screening of a 3.3.4 branched peptide boronic acids (BPBAs) library that bind selectively to the tertiary structure of RRE IIB. The library comprised of 46,656 unique sequences. We demonstrate that our highest affinity BPBA (BPBA1) selectively binds RRE IIB in the presence of competitor tRNAs as well as against six RRE IIB structural variants. Further, we show that the boronic acid moieties afford a novel binding mode towards RNA that is tunable; their Lewis acidity has critical effects on binding affinity. In addition, biophysical characterizations provide evidence that "branching" in these peptides is a key structural motif for multivalent interactions with the target RNA. Finally, RNA footprinting studies revealed that the BPBA1 binding site encompasses a large surface area that spans both the upper stem as well as the internal loop regions of RRE IIB. BPBA1 is cell permeable and non-toxic. In the next generation of branched peptides, a 3.3.4 branched peptide library composed of 4,096 unique sequences that featured boronic acid and acridine moieties was designed. We chose acridine as the amino acid side chain due to its potential for π-stacking interaction that provides high binding affinity to RNA target. The library was screened against HIV-1 RRE IIB RNA. Fifteen peptides were sequenced and four contained acridine alone and/or in conjunction with boronic acid moieties displayed dissociation constants lower than 100 nM. The ribonuclease protection assays of A7, a sequence that contains both boronic acid and acridine residues, showed a similar protection pattern compared to previous peptide BPBA1, suggesting that the 3.3.4 branched peptides shared similar structural elements and contacted comparable regions of the RRE IIB RNA. The results from this research indicated that "branching" in peptides imparts multivalent interactions to the RNA, and that functional groups such as boronic acid and acridine are key structural features for efficient binding and selectivity for the folded RNA target. We demonstrated that the branched peptides are cell permeable and non-toxic. / Ph. D.

No description available.