Pela primeira vez incêndios florestais são identificados em uma associação de fácies contendo a Flora Dicroidium nos sedimentos avermelhados do Triássico Médio (Ladiniano) na parte sul da Bacia do Paraná (Formação Santa Maria, Rio Grande do Sul). A extensão geográfica dessa assembleia de plantas foi, assim, estendida no Gondwana brasileiro. As análises por petrografia orgânica, fluorescência, microscopia eletrônica de varredura (MEV) e microscopia eletrônica de varredura (tipo field emission gun - MEV-FEG) revelaram a presença recorrente de carvão vegetal (charcoal) na sucessão vertical de fácies relacionadas a um modelo deposicional de fluxos efêmeros de baixa densidade do tipo inunditos. O carvão microscópico (micro-charcoal) ocorre como fragmentos comuns em diferentes fácies, enquanto que o carvão vegetal macroscópico (macro-charcoal) é representado por espécimes tridimensionais de lenhos atribuídos a gimnospermas (Pinaceae?) e por fragmentos achatados, finos e alongados atribuídos a pteridospermas (rachises de Dicroidium?) Os valores médios de reflectância da inertinita entre 2,80-6,61 %Ro medidos nos fragmentos de macro-charcoal evidenciaram processos de queima de alta temperatura, envolvendo tanto incêndios na copa quanto na interface copa-superfície. A recorrência de fragmentos queimados em várias fácies do perfil estudado indica a ocorrência de incêndios regionais que afetaram tanto as comunidades meso-xerófilas distais quanto às associações proximais higro- mesófilas, compostas majoritariamente por espécimes da Flora Dicroidium. A integração dos resultados obtidos a partir das múltiplas análises dos fragmentos de charcoal é consistente com um teor de oxigênio atmosférico superior a 20%. / For the first time wildfires are reported from an association of different facies containing a Dicroidium flora from the Middle Triassic (Ladinian) red beds in the southern part of the Paraná Basin (Santa Maria Formation, Rio Grande do Sul state). The geographical extension of the Dicroidium plant assemblage has thus been extended in the Brazilian Gondwana. Analyses through petrography, fluorescence microscopy, scanning (SEM) and field emission gun scanning electron microscopy (FEG-SEM) revealed recurrent charcoal presence in a vertical facies succession of depositional cycles related to ephemeral prograding low density flows. Microscopic charcoal occurs as common fragments within different facies whereas macroscopic charcoal is represented by tridimensional wood specimens assigned to gymnosperms (Pinaceae?) and by flattened, thin, elongated remains assigned to pteridospermophytes (rachises of Dicroidium?). Average reflectance values between 2.80-6.61 %Ro measured in the macro-charcoals evidenced burning processes of high temperature, involving fires both in the crown and in the crown-surface interface. The recurrence of charcoal in several facies of the studied profile indicates regional wildfires, which affected hinterland, meso-xerophyllous coniferous assemblages and marginal hygro-mesophyllous Dicroidium-like assemblages. The integration of results obtained from the multiple charcoal analyses is consistent with atmospheric oxygen content higher than 20%.

[Truncated abstract] Fire creates charcoal from the partial burning of biomass which results in a biologically inert form of carbonaceous (non-living) organic matter that, once integrated into soil and sediments, can persist for long periods of time. Charcoal has a large surface area with a high sorptive capacity for organic and inorganic substances. As a repository for metal and non-metal elements charcoal has been given little, if any, attention in the fields of geochemistry, agriculture and environmental monitoring . . . Despite the differences in charcoal surface area, soil charcoal achieved nearly 100% sorption of 0.5 and 5 μg/g Au from 0.03 M NaCl and 0.01M Ca(NO3)2 solution, almost independent of solution pH. At low pH, charcoal sorbed between 10 and 60% of Cu with initial additions of 2 and 20 μg Cu/g. Similarly, between 15 and 40% of Zn was sorbed by charcoal with initial additions of 5 and 40 μg Zn/g. The role of surface area in sorption of elements by charcoal is clearly only one factor that is important. Charcoal aromatic and aliphatic chemical functional groups, which can be distinguished from other forms of organic matter through spectroscopic determination, are also important in charcoal’s capacity to sorb elements. Accumulation of Be, B, Na, Mg, Al, Si, K, Ca, Ti, Mn, Co, Ni, Cu, Se, Mo, Ba, Au and Pb (out of a range of 29 elements) in soil charcoal, above the concentrations in the matrix soil and plant reference charcoal, was confirmed by ICP-MS analysis. Concentrations of V, Mn, Co, Ni, Cu, Mo, Ba, Au, Pb and Bi were higher in soil charcoal than in values quoted for gossans and pisolites in the field area region (Smith and Perdrix, 1983). Higher values of Au in soil charcoal were associated with considerable amounts of included clay minerals and higher values of other elements including Mo, Mn and Fe.

Master of Science / Department of Agronomy / Scott A. Staggenborg / With the increase in bio-energy production there is also an increase in by-products. Without proper disposal, these by-products might cause future economic and/or ecological problems. Land application has potential as a disposal and/or nutrient cycling method if these by-products have nutritive value for agricultural crops. The purpose of the study was to compare the use of two by-products of bio-energy production, dry distillers grains (ethanol) and charcoal(pyrolysis), as fertilizer with urea in corn (Zea mays L.). The experiment consisted of four location-years in Kansas. Treatments were dry distiller’s grains (DDG) no-till and tilled for four location-years and char no-till and tilled for three location-years. No-till urea was used as a baseline for comparison at all location-years. The Nitrogen rates ranged from 45 to 180 kg N ha-1. All source material was spring applied before tillage and planting. The corn yields for DDGs and urea were the almost the same across tillage treatments and locations. For DDG no-till, DDG tilled, and urea, the rates at which to achieve the same yields were 97, 111, 78 kg N ha-1, respectively. Corn yields for char at all rates and tillage treatments were the same as no fertilizer. The char, because of immobilization or lack of decomposition, did not contribute to the nitrogen needs of the corn. Neither material showed any inhibitory or otherwise negative effects on the corn in terms of grain yield compared with the control. But both DDGs and char had to have large amounts of material applied to achieve the same amount of nitrogen as urea. Land application of DDGs and char has potential merit for disposal/nitrogen cycling with DDGs being preferred for its nitrogen contribution.

This dissertation focuses on the animated, charcoal, hand-drawn films of William Kentridge‟s Drawings for Projection series (1989—2003). At the beginning of this study, Kentridge‟s films are positioned as a dialectic of self and memory as embodied in a post-colonial South African setting. The series itself was selected as being representative of his artistic oeuvre. They are a closed-ended narrative, using a ground-breaking animation technique, created by the artist himself (Christov-Bakargiev 1998; Godby 1982). They were made by Kentridge during a specific South African cultural and historical period: beginning with Johannesburg, 2nd Greatest City after Paris, made in 1989 at the height of apartheid; through to Tide Table, made in 2003 at the beginning of post post-apartheid South Africa. The hypothesis presented is that Kentridge‟s films have memory as their main theme. Memory itself takes different forms, and the discourse of memory deals with, for instance: memorialisation; repressed memories; traumatic memories; the unconscious and memories; and “postmemory”. How he depicts memories of his own and those of others is at the centre of this research. Using qualitative research methodology, with contextualisation (socio-historical and cultural) and comparative studies (apartheid and the Holocaust; different artistic representations of memory, for example Pascal Croci and William Kentridge; and Anselm Kiefer and William Kentridge) being part of the research design, this thesis has sought to substantiate this hypothesis. Further substantiation and clarification has been expounded by referencing seminal works in the field, such as those of Sigmund Freud (1899: “screen memories”; 1917: trauerarbeit); Roland Barthes (1981: the punctum / spacio-temporal continuum); Pierre Nora (1989: “lieux de mémoiré” / “sites of memory”); Henri Raczymow (1994: “memoire trouée” / “memory shot through with holes”); Richard Terdiman (1993: poesis); Marianne Hirsch (1997: “postmemory”); and Hayden White (1996: historical metafiction); among others. There have already been numerous references to how William Kentridge has depicted the ephemeral nature of memory / memories (Boris 2001; Cameron, Christov-Bakargiev and Coetzee, 1999; Christov-Bakargiev 1998; Sitas 2001). However an in-depth, hermeneutic, comparative analysis has not yet been undertaken. This study is therefore significant in that it explicates William Kentridge‟s works, making the following contributions: to the scholarship on Kentridge‟s work; to a South African perspective to the growing field of trauma studies; and to the apartheid and post-apartheid reflections on re-remembering and forgetting, memorialisation, forgiveness and guilt. Through socio-cultural and historical comparisons as well as artistic contrasts, the films themselves are acknowledged as an important source of reference of South African society. They are a documentation of life lived during apartheid and post-apartheid South Africa. / Department of Communication Science / D.Litt. et Phil.

In November of 1984 and 1985, Euphorbia lathyris was planted into a field naturally infested with Macrophomina phaseolina located at the Campbell Avenue Farm in Tucson, Arizona. Plants without foliar symptoms and rhizosphere soil were sampled regularly from emergence until the following May or June. Soil rhizosphere populations ranged from 0.7-3.0 cfu/g soil in 1985 to 8.0-24.1 cfu/g soil in 1986, and did not change significantly over either growing season (P > 0.05). Both the incidence of disease and the number of infection sites per cm of root increased significantly (P < 0.05) over each growing season and were not related to rhizosphere soil populations of M. phaseolina (P > 0.05). The distribution of infection sites along the tap root over both growing seasons remained the same in that most were located in the top 0-7 cm of tap root. Infected E. lathyris without apparent symptoms were subjected to low-water and high-temperature stress treatments in growth chambers. Root infection was not found to be dependent upon any stress. Lesion development was significantly dependent upon the imposition of any stress treatment, and further root colonization was significantly dependent upon low-water stress (P < 0.05). M. phaseolina was consistently recovered from asymptomatic roots. A consistently lower leaf water potential was measured on infected E. lathyris than from non-infected controls when no stress treatment was applied. Polyclonal antisera made against hyphae and microsclerotia of M. phaseolina was not successful in detecting this pathogen in E. lathyris by I-ELISA. Antisera applied to fresh thin sections of infected plant tissue was effective in staining hyphae of M. phaseolina when used with a second antibody conjugated to fluorescence isothiocyanate or to an enzyme (to which a substrate was added to "stain" hyphae).

No description available.

A pollen profile from varved lake sediments sampled at 10-year intervals and spanning the past 1000 years is analyzed to understand the effects of climate change and anthropogenic activity on forests in southwestern Quebec. The forests responded rapidly to changes in temperature and precipitation during the Medieval Warm Period and Little Ice Age as well as to land-use changes associated with the European Settlement of the area. The transition into the Little Ice Age was abrupt and had significant impact on the pollen production within a couple of decades. A synthesis of this record with other high-resolution and well-dated pollen data from the conifer-hardwood forest of eastern North America shows consistent results across the whole area, indicating that very-high resolution pollen data can provide insight into multi-decadal climate variability and its impact on forest vegetation. Tree-ring records from the region show inter-annual fluctuations not always consistent between sites, while high-resolution pollen data record multi-decadal to century changes which enable us to interpret climatic effects on plant communities.

A collaborative pilot study of the microflora on biological activated charcoal (BAC) filters employed in the tertiary treatment of drinking water revealed the principle bacterial genera to be Pseudomonas, Alcaligenes, Achromobacter, Bacillus, Micrococcus, Corynebacterium, Chromobacterium, Microcyclus and Paracoccus. The microbial population of the filters paralleled seasonal carbon dioxide production. Of particular interest were the effects of the BAC miroorganisms upon precursors of trihalomethanes (THMs). Mixed populations of BAC microorganisms were cultivated for 50 days in a mineral salts-humic acid medium. It was concluded that (1) the BAC microflora enhances the absorptive capacity of the filters; (2) chemico-physical and biological processes operate in concert to lower the concentration of precursors of THMs; and (3) few bacterial pathogens establish themselves on the filters.

Collection of poetry by Deborah Brink in four parts, submitted in August of 2004.

Student Number : 0306319G - MSc Research Report - School of Geography, Archaeology and Environmental Studies - Faculty of Science / Combustion of fuel wood, charcoal and non-woody biofuels is a daily practice for about half of the world’s population. Combustion of biofuel is a major source of trace gases, with domestic biomass burning contributing about 17% carbon dioxide (CO2), 13% carbon monoxide (CO) and 6% nitrous oxide (N2O) to the global budget. In Africa, where there is a growing population, domestic biofuel emissions are a particularly important source of trace gases. The most important source of biomass fuels in Africa is wood fuel (wood and charcoal), crop residues and animal dung. In this project, the amount of domestic biofuel used in rural households across southern Africa was measured daily over a nine month period. This data was used to estimate the trace gas production from domestic fires throughout Southern Africa. Results indicate that RSA contributed the most trace gases to the regional budget (9.12 Tg C yr-1 of CO2, 0.89 Tg C yr-1 of CO, 10.77 Gg N yr-1 of NO and 30.25 Gg C yr-1 of CH4) and Botswana the least (0.25 Tg yr-1 of CO2, 0.02 Tg yr-1 of CO, 0.29 Gg yr-1 of NO and 0.83 Gg yr-1 of CH4). Fuel wood is the dominant fuel type used in all southern African countries, whereas charcoal was used in RSA, Mozambique and Zambia and maize residues in Malawi only. CO2 was the gas emitted in the largest quantities, with fuel wood and charcoal in RSA contributing the most (8.71 Tg yr-1 and 0.41 Tg yr-1 respectively), while CO2 from maize residue was highest in Malawi (0.82 Tg yr-1). More trace gases were emitted in the dry season than wet season particularly in Malawi and Mozambique. For the entire region the annual CO2, CO, NO and CH4 emissions produced 23.0 Tg C, 2.2 Tg C, 29.4 Gg N and 81.4 Gg C, respectively.