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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

"So Calamitous a Situation": The Causes and Course of Dunmore's War, 1744-1774

Rife, James Phillip 11 September 1999 (has links)
Dunmore’s War was the last colonial war in America before the Revolution. This conflict was the culmination of nearly thirty years of intrigue and violence in the so-called “Western Waters” of the trans-Allegheny region of Virginia, which included the valleys of the Ohio River and its lower tributary system. This thesis traces the origins of the war, and suggests that, among other things, the provisions in the Royal Proclamation of 1763 for the westward extension of the Indian boundary line and soldier settlement contributed mightily to the instigation of the war between Virginia and the Shawnees. Indeed, Virginia’s former provincial soldiers took advantage of the waning authority of the royal government in the west to secure their bounty lands, at the expense of the Shawnees and their allies in the Ohio Valley. Matters reached a climax during the curious administration of Virginia’s last colonial governor, Lord Dunmore. Dunmore, who harbored his own western land ambitions, allied himself with the soldiers and land speculators, and instituted policies aimed at extending Virginia’s jurisdiction over the Ohio Valley and Kentucky against the directives of his superiors in London. Accordingly, the thesis examines the royal governor’s motivations, policies, and conduct in the events leading up to the conflict. Finally, the thesis contributes a fresh, complete narrative of the war itself, which has been lacking for some time in the field of Virginia History. / Master of Arts
2

The effect of alfalfa and cornstalk round bale processing type on animal performance, wastage, preference, and mixing characteristics

Jones, Spencer Q. January 1900 (has links)
Master of Science / Department of Animal Sciences and Industry / Joel M. DeRouchey / Seven experiments were conducted to evaluate the effect of alfalfa and cornstalk round bale processing type on animal performance, wastage, preference, and mixing characteristics. All bales were baled using a round baler (John Deere) that had the ability to cut forage being baled prior to wrapping. This machine processed all bales used in these experiments, with those termed conventional being baled with the cutter disengaged. In Exp. 1, 46 heifers (initially 270 kg BW) were used in a 27 d experiment with ADG being higher (P < 0.01) for heifers consuming precut alfalfa compared to conventional alfalfa in ring feeders. However, there was no difference in final BW (P = 0.56) between conventional and precut treatments. In Exp. 2, 46 heifers were used to show there was no (P > 0.05) difference in forage wastage from ring feeders between precut or conventional alfalfa. In Exp. 3, 26 beef heifers, (initially 305 kg) were used to show that there was no (P = 0.48) difference in the preference of conventional alfalfa or precut alfalfa when offered simultaneously in different ring feeders for 2 d. In Exp. 4, 75 bulls (initially 317 kg BW) were used to show that tub ground bales had smaller TMR particle size (P = 0.01) than TMR’s with conventional or precut alfalfa bales. In Exp. 5, 60 heifers (initially 332 kg BW) were used to show that different discharge locations from each of the different cornstalk treatments had similar (P > 0.11) DM, CP, ADF, and NDF. Mixing time and fuel usage of a vertical mixer were evaluated in Exp. 6 and 7. In Exp. 6, bale mixing time was shorter (P < 0.05) for precut alfalfa compared to conventional alfalfa bales. Fuel usage per bale was lower (P < 0.001) for precut alfalfa bales compared to conventional alfalfa bales. In Exp. 7, precut cornstalk bale mixing time was shorter (P < 0.001) than conventional cornstalk bales. Fuel usage was similar (P > 0.05) among precut and conventionally-processed cornstalk bales. In conclusion, precutting alfalfa or cornstalk bales prior to net wrapping improved heifer performance and decreased mixing time and tractor fuel usage, but did not affect wastage and preference.
3

Exploring Cornstalk and Corn Biomass Silage Retting as a New Biological Fibre Extraction Technique

Campbell Murdy, Rachel January 2013 (has links)
Presently there are two forms of biological fibre extraction, water retting or dew retting, which use bacteria or fungi, respectively. Microbial action results in release of the cellulose fibres due to modification of the pectin, hemicellulose and lignin content from parenchyma cells and the middle lamellae. Water retting results in pollution, high costs associated with labour and drying, as well as significant waste water production, while disadvantages to dew retting include the need for appropriate climates, variable and inferior fibre quality, risks of over-retting as well as health effects due to dust and fungal contaminants. The overall objective of this research was to explore silage retting as a new pre-processing technique allowing use of available farm infrastructure and contained retting conditions to produce plant-derived fibres with improved physical and chemical characteristics suitable for application in biocomposites. The corn processing ability of the hemp retting agents Clostridium felsineum and Bacillus subtilis was also investigated. Pleiotropic and/or crop management practices were assessed by comparing the physico-mechanical properties and the microbial populations during silage fermentation of genetically equivalent conventional, Roundup Ready® (RR) and Bt-Roundup Ready® (Bt-RR) corn isolines. Potential recovery of volatile organic acids in silage retting effluent as value-added chemicals was also explored. The results indicated that C. felsineum is an effective corn retting agent given the effective release of the fibre bundles from the corn pith, with B. subtilis contributing to the retting process by reducing the oxygen content and providing the required anaerobic conditions for clostridial growth. The native microflora present in the plant phyllosphere also showed some retting ability. Composition, thermostability and mechanical properties of the biocomposites produced using the fibres from the retted corn were all found to vary depending on the variety of corn. Specifically, retted Bt-RR cornstalk showed a 15°C increase in onset of degradation. Divergences between corn silage microbial communities analyzed by community-level physiological and enzyme activity profiling indicated that metabolic shifts were time-, region-, and contaminant-sensitive. Acetic and butyric acid production in silage retting effluent was found to be highest under anaerobic conditions and was also influenced by corn hybrid variety, although a specific variety was not identified as most or least favourable for organic acid production due to high variability. Bt-RR cornstalk material was found to have higher cellulose content and better thermostability with an onset of degradation of up to 45°C higher than its genetic RR and conventional counterparts. However, fibres from the RR corn isoline produced biocomposites with the highest flexural strength and modulus. RR cornstalk-reinforced polypropylene showed a 37 and 94% increase in flexural strength and modulus, respectively when compared to the mechanical properties of the pure polypropylene. The Bt-RR and conventional varieties produced biocomposites with an average increase of 26.5% in flexural strength and 83.5% in flexural modulus. The thermostability of ensiled corn biomass was found to be influenced by region, use of inoculants and silage treatment, while the silage treatment accounted for most of the variability in corn biomass composition. Polypropylene matrix biocomposites produced with (30 wt%) pre- and post-silage corn did not show significant differences in mechanical properties. However, ensiled corn resulted in an increase in fibres and potential microbial biomass of smaller particle sizes with more optimal thermostability and purity, producing biocomposites with higher flexural strength and modulus especially at higher extrusion temperatures. Cornstalk is an effective reinforcement material, producing biocomposites with higher flexural strength, flexural modulus and impact strength. Whole corn biomass presents a potential alternative to other plant fibres, especially as filler material. Silage retting resulted in fibres with a higher thermostability and smaller particle size distribution that, given their already smaller aspect ratio, could result in better mechanical properties in thermoplastics with a higher melting temperature or biocomposites requiring higher shear for mixing.
4

Exploring Cornstalk and Corn Biomass Silage Retting as a New Biological Fibre Extraction Technique

Campbell Murdy, Rachel January 2013 (has links)
Presently there are two forms of biological fibre extraction, water retting or dew retting, which use bacteria or fungi, respectively. Microbial action results in release of the cellulose fibres due to modification of the pectin, hemicellulose and lignin content from parenchyma cells and the middle lamellae. Water retting results in pollution, high costs associated with labour and drying, as well as significant waste water production, while disadvantages to dew retting include the need for appropriate climates, variable and inferior fibre quality, risks of over-retting as well as health effects due to dust and fungal contaminants. The overall objective of this research was to explore silage retting as a new pre-processing technique allowing use of available farm infrastructure and contained retting conditions to produce plant-derived fibres with improved physical and chemical characteristics suitable for application in biocomposites. The corn processing ability of the hemp retting agents Clostridium felsineum and Bacillus subtilis was also investigated. Pleiotropic and/or crop management practices were assessed by comparing the physico-mechanical properties and the microbial populations during silage fermentation of genetically equivalent conventional, Roundup Ready® (RR) and Bt-Roundup Ready® (Bt-RR) corn isolines. Potential recovery of volatile organic acids in silage retting effluent as value-added chemicals was also explored. The results indicated that C. felsineum is an effective corn retting agent given the effective release of the fibre bundles from the corn pith, with B. subtilis contributing to the retting process by reducing the oxygen content and providing the required anaerobic conditions for clostridial growth. The native microflora present in the plant phyllosphere also showed some retting ability. Composition, thermostability and mechanical properties of the biocomposites produced using the fibres from the retted corn were all found to vary depending on the variety of corn. Specifically, retted Bt-RR cornstalk showed a 15°C increase in onset of degradation. Divergences between corn silage microbial communities analyzed by community-level physiological and enzyme activity profiling indicated that metabolic shifts were time-, region-, and contaminant-sensitive. Acetic and butyric acid production in silage retting effluent was found to be highest under anaerobic conditions and was also influenced by corn hybrid variety, although a specific variety was not identified as most or least favourable for organic acid production due to high variability. Bt-RR cornstalk material was found to have higher cellulose content and better thermostability with an onset of degradation of up to 45°C higher than its genetic RR and conventional counterparts. However, fibres from the RR corn isoline produced biocomposites with the highest flexural strength and modulus. RR cornstalk-reinforced polypropylene showed a 37 and 94% increase in flexural strength and modulus, respectively when compared to the mechanical properties of the pure polypropylene. The Bt-RR and conventional varieties produced biocomposites with an average increase of 26.5% in flexural strength and 83.5% in flexural modulus. The thermostability of ensiled corn biomass was found to be influenced by region, use of inoculants and silage treatment, while the silage treatment accounted for most of the variability in corn biomass composition. Polypropylene matrix biocomposites produced with (30 wt%) pre- and post-silage corn did not show significant differences in mechanical properties. However, ensiled corn resulted in an increase in fibres and potential microbial biomass of smaller particle sizes with more optimal thermostability and purity, producing biocomposites with higher flexural strength and modulus especially at higher extrusion temperatures. Cornstalk is an effective reinforcement material, producing biocomposites with higher flexural strength, flexural modulus and impact strength. Whole corn biomass presents a potential alternative to other plant fibres, especially as filler material. Silage retting resulted in fibres with a higher thermostability and smaller particle size distribution that, given their already smaller aspect ratio, could result in better mechanical properties in thermoplastics with a higher melting temperature or biocomposites requiring higher shear for mixing.
5

Criação de Elasmopalpus lignosellus (Zeller, 1848) (Lepidoptera: Pyralidae) em dieta artificial em diferentes temperaturas e seleção de linhagens de Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) para seu controle em arroz / Rearing of Elasmopalpus lignosellus (Zeller, 1848) (Lepidoptera: Pyralidae) in artificial diet at different temperatures and Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) strain selection for pest control in rice

Andrade, Rízia da Silva 15 January 2013 (has links)
Elasmopalpus lignosellus (Zeller, 1848) (Lepidoptera: Pyralidae), ou broca-do-colo, é uma importante praga polífaga, poucas informações estão disponíveis sobre seu controle biológico. O objetivo desse trabalho foi estudar a biologia de E. lignosellus criada em dieta artificial em diferentes temperaturas, visando obter informações a respeito da praga para estratégias de manejo integrado e selecionar uma linhagem de Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae), em laboratório, para possível utilização desse parasitoide em programas de controle biológico do elasmo em campo, visando à fase inicial (ovo) de desenvolvimento da praga. Foram desenvolvidas as seguintes etapas para atingir os objetivos propostos: 1. Efeito da temperatura no período de incubação e no período lagarta-adulto de E. lignosellus; 2. Tabela de vida de fertilidade de E. lignosellus; 3. Estudos comportamentais e de local de oviposição de E. lignosellus; 4. Seleção de linhagens de T. pretiosum, visando ao controle de E. lignosellus. Com base nos resultados obtidos na presente pesquisa, pode-se concluir: a faixa térmica de desenvolvimento de Elasmopalpus lignosellus (Zeller, 1848) situou-se entre 10°C e 37 e 38°C, suportado, portanto, altas temperaturas; as maiores viabilidades do período lagarta-adulto a 30 e 32°C confirmaram a adaptação do inseto às altas temperaturas; a 32°C, o inseto tem elevada taxa líquida de reprodução, ou seja, aumentou 18,30 vezes a cada geração; o período de oviposição de E. lignosellus se concentrou entre 20 e 22 horas, sempre na escotofase; a grande maioria dos ovos de E. lignosellus foi colocada de forma exposta, facilitando o parasitismo por parasitoides de ovos, no caso Trichogramma pretiosum Riley, 1879; a linhagem T. pretiosum selecionada para o controle de ovos de E. lignosellus é da região do cerrado, indicando a especificidade do parasitoide por determinadas condições de clima. / Elasmopalpus lignosellus (Zeller, 1848) (Lepidoptera: Pyralidae), or cornstalk borer, is an important polyphagous pest and there is little knowledge regarding its biological control. The aim of this research was to study the biology of E. lignosellus reared on artificial diet under different temperatures in order to gather information to (i) develop integrated management strategies and (ii) select strains of the egg parasitoid Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) for biological control programs. The following steps were performed to achieve the proposed goals: 1. Temperature effect on incubation period and E. lignosellus immature-adult period; 2. Table life of E. lignosellus fertility; 3. E. lignosellus behavior studies and oviposition preference; 4. T. pretiosum strain selection aiming E. lignosellus control. Based on the results, it\'s possible to conclude that: the ideal development temperature threshold of E. lignosellus is between 10°C and 37-38°C, therefore, it tolerates high temperatures; the higher immature-adult period viability at 30 and 32°C supports E. lignosellus\'adaptation to high temperatures; at 32ºC, E. lignosellus show elevated the net reproductive rate, since it increased 18.30 times for each genaration; E. lignosellus\' oviposition period was concentrated between 20 and 22 hours, always at the scotophase; most of E. lignosellus eggs was laid exposed, allowing parasitism by the egg parasitoidTrichogramma pretiosum; the selected T. pretiosum strain for E. lignosellus egg control is originated in the brazilian savannah, pointing out the parasitoid\'s specificity to certain climate conditions.
6

Criação de Elasmopalpus lignosellus (Zeller, 1848) (Lepidoptera: Pyralidae) em dieta artificial em diferentes temperaturas e seleção de linhagens de Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) para seu controle em arroz / Rearing of Elasmopalpus lignosellus (Zeller, 1848) (Lepidoptera: Pyralidae) in artificial diet at different temperatures and Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) strain selection for pest control in rice

Rízia da Silva Andrade 15 January 2013 (has links)
Elasmopalpus lignosellus (Zeller, 1848) (Lepidoptera: Pyralidae), ou broca-do-colo, é uma importante praga polífaga, poucas informações estão disponíveis sobre seu controle biológico. O objetivo desse trabalho foi estudar a biologia de E. lignosellus criada em dieta artificial em diferentes temperaturas, visando obter informações a respeito da praga para estratégias de manejo integrado e selecionar uma linhagem de Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae), em laboratório, para possível utilização desse parasitoide em programas de controle biológico do elasmo em campo, visando à fase inicial (ovo) de desenvolvimento da praga. Foram desenvolvidas as seguintes etapas para atingir os objetivos propostos: 1. Efeito da temperatura no período de incubação e no período lagarta-adulto de E. lignosellus; 2. Tabela de vida de fertilidade de E. lignosellus; 3. Estudos comportamentais e de local de oviposição de E. lignosellus; 4. Seleção de linhagens de T. pretiosum, visando ao controle de E. lignosellus. Com base nos resultados obtidos na presente pesquisa, pode-se concluir: a faixa térmica de desenvolvimento de Elasmopalpus lignosellus (Zeller, 1848) situou-se entre 10°C e 37 e 38°C, suportado, portanto, altas temperaturas; as maiores viabilidades do período lagarta-adulto a 30 e 32°C confirmaram a adaptação do inseto às altas temperaturas; a 32°C, o inseto tem elevada taxa líquida de reprodução, ou seja, aumentou 18,30 vezes a cada geração; o período de oviposição de E. lignosellus se concentrou entre 20 e 22 horas, sempre na escotofase; a grande maioria dos ovos de E. lignosellus foi colocada de forma exposta, facilitando o parasitismo por parasitoides de ovos, no caso Trichogramma pretiosum Riley, 1879; a linhagem T. pretiosum selecionada para o controle de ovos de E. lignosellus é da região do cerrado, indicando a especificidade do parasitoide por determinadas condições de clima. / Elasmopalpus lignosellus (Zeller, 1848) (Lepidoptera: Pyralidae), or cornstalk borer, is an important polyphagous pest and there is little knowledge regarding its biological control. The aim of this research was to study the biology of E. lignosellus reared on artificial diet under different temperatures in order to gather information to (i) develop integrated management strategies and (ii) select strains of the egg parasitoid Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) for biological control programs. The following steps were performed to achieve the proposed goals: 1. Temperature effect on incubation period and E. lignosellus immature-adult period; 2. Table life of E. lignosellus fertility; 3. E. lignosellus behavior studies and oviposition preference; 4. T. pretiosum strain selection aiming E. lignosellus control. Based on the results, it\'s possible to conclude that: the ideal development temperature threshold of E. lignosellus is between 10°C and 37-38°C, therefore, it tolerates high temperatures; the higher immature-adult period viability at 30 and 32°C supports E. lignosellus\'adaptation to high temperatures; at 32ºC, E. lignosellus show elevated the net reproductive rate, since it increased 18.30 times for each genaration; E. lignosellus\' oviposition period was concentrated between 20 and 22 hours, always at the scotophase; most of E. lignosellus eggs was laid exposed, allowing parasitism by the egg parasitoidTrichogramma pretiosum; the selected T. pretiosum strain for E. lignosellus egg control is originated in the brazilian savannah, pointing out the parasitoid\'s specificity to certain climate conditions.

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