Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 150-156). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 150-156). Also available on the Internet.

Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (May 20, 2007) Vita. Includes bibliographical references.

No description available.

This thesis compared the bird and mammal populations utilizing three multiflora rose hedgerows in Delaware County, Indiana during a one year period.. Results were based on weekly observations and snap-trapping records. Relative abundance and frequency indices were used in comparing populations. Birds were also classified according to their seasonal occurrence on the areas, and activities of birds and mammals were reported.This study showed that the species composition of the areas was similar but that population sizes and degree of species utilization varied as a result of adjacent land use and disturbance rather than the length or volume of the hedgerows.Ball State UniversityMuncie, IN 47306

The purpose of this thesis is the determination of a minimum market price for Short-Rotation Forestry (SRF) willow biomass grown in monoculture and windbreaks in Quebec and Ontario. Full cost budgeting was used and developed on a Microsoft Excel spreadsheet. Harvest cycles of 3 and 4 years for monoculture plantations, and 8 years for windbreaks were investigated. Estimates for establishment and other preharvest costs were obtained from mid-sized (5 hectares) commercial SRF willow plots in Quebec and Ontario. / For the monoculture plantations, irrespective of cycle length, and using the base case figures, the final delivery cost of willow biomass ranged between 74-126 $/odMg and 63--109 $/odMg based on current and projected costs respectively. These hold for yields between 7 and 11 odMg/ha/yr. Moreover, the 4-year cycle was revealed to be more economically efficient than a 3-year cycle. Along with yield, the main cost factors affecting the economics of SRF monoculture plantations are: harvesting, transportation to a processing plant, land lease management. For the two major energy markets, ethanol and electricity production (biomass in replacement of coal), SRF willow biomass in monoculture plantations does not appear to be a viable feedstock given present technology and yields. In the short run, a more promising outlet for willow biomass is space heat production for small buildings, farm complexes, etc. In this market, many potential buyers can afford to pay a higher price for biomass than ethanol or electricity utilities. / In the windbreak system, biomass could be produced for between 44 and 68 $/odMg, assuming that yields between 12 to 20 odMg/ha/yr can be achieved. At this price, windbreak biomass is not a competitive feedstock for ethanol or electricity generation, but is attractive for space heat production. (Abstract shortened by UMI.)

The research objective was to calibrate a model to simulate odour dispersion downwind from natural windbreaks and then, use this model to observe the effect of windbreak characteristics and climatic conditions on the size of the odour dispersion plume. Computational fluid dynamic (CFD) models were used for the simulations because of their capability in reproducing turbulent wind conditions. The model was initially calibrated to ensure the proper velocity recovery ratio (VRR), and then to reproduce odour plumes measured in the field by three groups of four panellists. / The visual and statistical analysis of the field panellist observations indicated that a windbreak with an optical porosity of 0.35 could reduce by 21% the length of the odour dispersion plume, as compared to a site without a windbreak. Also, these analyses indicated that the site with a windbreak offering an optical porosity of 0.55 had no significant impact on the length of the odour plume, as compared to the site without a windbreak. / The models selected for the simulations were the Fluent 6.2 standard k-epsilon and SST k-o models. Their odour dispersion calibration indicated that both models can accurately reproduce the field measured odour hedonic tone and odour concentration by transforming the odour mass fraction computed by the models into the hedonic tone with a power function, and then into the odour concentration with an exponential function. The correlations between the simulated and measured absolute HT and between the simulated and measured odour concentrations were statistically significant (P < 0.01). However, the SST k-o was preferred over the standard k-epsilon because it could physically better reproduce the high turbulence conditions created by the windbreak. / The SST k-o model simulations indicated that odour plume length was mostly affected by windbreak porosity and height, as well as distance from the source. In terms of climatic conditions, odour plume size was mostly affected for atmospheric stability conditions which generally established ambient wind speed and rate of change of temperature. Wind direction has an impact on the length of the odour plume and the formation of a fin intensifying odour concentration near the windbreak, where an angle of 45º produces the shortest odour plume and the largest fin. / Key words: Simulation; odour; dispersion; natural Windbreak; CFD.

No description available.

Thesis (M.S.) -- Mississippi State University. Department of Biological Sciences. / Title from title screen. Includes bibliographical references.

Made available in DSpace on 2014-06-11T19:32:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-12-18Bitstream added on 2014-06-13T19:42:23Z : No. of bitstreams: 1 nunes_ma_dr_jabo.pdf: 2056446 bytes, checksum: 2c54de2b440ec113fde3178a2d46cea8 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho teve como objetivo investigar a possibilidade de plantas utilizadas como cercas-vivas e quebra-ventos, bem como plantas invasoras comuns em pomares cítricos, hospedarem o Citrus leprosis virus, cytoplasmic type (CiLV-C) e servirem de inóculo para os citros. Em casa-de-vegetação, ácaros provenientes de uma criação-estoque sobre frutos de laranja Pêra, com sintomas de leprose, foram transferidos para folhas isoladas por barreira adesiva de: hibisco (Hibiscus rosa-sinensis L.), malvavisco (Malvaviscus arboreus Cav.), grevílea (Grevilea robusta A. Cunn.), urucum (Bixa orellana L.), trapoeraba (Commelina benghalensis L.) e laranja [Citrus sinensis (L.) (Osbeck)]. Após 90 dias da infestação, os ácaros descendentes foram transferidos para mudas de laranja “Natal”. Amostras de tecidos das plantas testes se mostraram positivos para todas as plantas inoculadas com ácaros virulíferos por análise de RT-PCR utilizando-se de “primers” específicos para detecção do CiLV-C e foram verificadas a presença de partículas virais em hibisco, laranja, malvavisco, e trapoeraba em análise de Microscopia Eletrônica de Transmissão (MET). Em campo, laranja, malvavisco, grevílea e sansão-do-campo foram plantados próximos a plantas-teste de laranja e infestados com ácaros virulíferos. Essas espécies foram avaliadas quanto à presença de ácaros, à incidência e à severidade da doença. Foi possível observar que a incidência e a severidade da leprose foram maiores nas plantas de laranja que estavam próximas às laranjeiras infestadas, seguidas daquelas próximas a malvavisco e sansão-do-campo, que diferiram estatisticamente de grevílea. Estes resultados indicam que as plantas analisadas podem ser importantes na epidemiologia da doença. / The objective of this work was to investigate the possibility that hedgerows, windbreaks, and weeds normally found in citrus orchards could host Citrus leprosis virus, cytoplasmic type (CiLV-C), serving as its source of inoculum. In greenhouse, mites reared onto sweet orange fruits var. “Pêra” symptomatic for leprosis were transferred to leaves, isolated by adhesive barrier, of Hibiscus rosasinensis, Malvaviscus arboreus, Grevilea robusta, Bixa orellana, Commelina benghalensis and Citrus sinensis. After 90 days of infestation, the descendant mites were transferred to Natal sweet orange plants to verify the transferability of the virus back to citrus. Non-viruliferous mites, which had no feed access to diseased tissue, were used as control. Localized lesions (chlorotic or necrotic spots, ringspots) developed in almost all tested plants. Tissue samples of plants infested with viruliferous and non-viruliferous mites were submitted to RT-PCR with specific primers to CiLV-C. Transmission electron microscopy analyses detected the presence of viral inclusions in C. benghalensis H. rosa-sinensis, M. arboreus, and C. sinensis. In experimental groves, C. sinensis, G. robusta, M. arboreus and Mimosa caesalpinaefolia were planted and infested with viruliferous mites around citrus plants. There was a clear variation in leprosis incidence and severity observed in sweet orange plants depending on the alternative host cultivated beside them. The higher intensity of the disease was observed in sweet orange plants that were close to C. sinensis, followed by those close to M. arboreus and Mimosa caesalpinaefolia. The intensity of leprosis in sweet oranges planted near G. robusta was significantly lower than in those cultivated close to the other hosts. These results suggest that the alternative hosts tested can play a role in the epidemiology of the disease, serving as sources of inoculum of the virus.