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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.
361

Análise do ITS1 do DNA ribossômico em espécies do complexo Anastrepha fraterculus (Diptera: Tephritidae) / Analysis of ITS1 of ribosomal DNA in Species of the Anastrepha fraterculus complex (Diptera: Tephritidae).

Prezotto, Leandro Fontes 14 April 2008 (has links)
As espécies de moscas-das-frutas da família Tephritidae são consideradas importantes pragas da fruticultura mundial por utilizarem vários frutos de valor comercial como substrato para desenvolvimento do seu estágio de larva. O gênero Anastrepha é endêmico do Continente Americano e compreende cerca de 200 espécies descritas, das quais 99 ocorrem no Brasil. Dentre essas espécies, destaca-se a espécie nominal Anastrepha fraterculus (sensu lato), que compreende um complexo de espécies crípticas, quatro das quais foram reconhecidas, até o momento, A. sp.1, A. sp.2 e A. sp.3 (Brasil) e A. sp.4 encontrada no Equador. O presente trabalho buscou a caracterização da variabilidade do espaçador ITS1 do DNA ribossômico de A. sp.1, A. sp.2 e A. sp.3 em amostras populacionais de diversas localidades do Brasil e a análise desse espaçador em amostras de outras regiões das Américas do Sul, Central e México. O ITS1 mostrou ser um marcador bastante útil para análises filogenéticas entre espécies próximas. Os fragmentos amplificados com os iniciadores 18SF e 5.8SR, construídos neste trabalho, continham cerca de 900 pb, não havendo diferenças significativas entre as amostras. Os fragmentos continham uma seqüência parcial do gene 18S, o ITS1 completo e o início do gene 5.8S. O ITS1 variou de 539 a 584 bases. Todos os exemplares apresentaram uma quantidade muito maior de base AT (entre 77,6 a 88,6%). O índice de similaridade entre as amostras variou de 88% a 99,8%. Não foram observadas diferenças significativas intraespecíficas entre as seqüências de amostras populacionais das entidades brasileiras do complexo. A análise filogenética feita pelo programa POY gerou muitas árvores igualmente parcimoniosas. A árvore de consenso estrito agrupou as amostras em clados distintos. O clado (grupo externo) formado por C. capitata e C. rosa foi colocado em um ramo distinto e no outro clado, todas as amostras de Anastrepha. O clado de A. fraterculus, separou as amostras do México e Guatemala das demais, que formaram outro clado. Dentro deste clado, foram formados dois subgrupos, um com as amostras do Peru e Equador e um com as amostras do Brasil e Argentina. Dentro desses clados houve separação em sub-grupos de amostras de cada região geográfica, sendo observada, com algumas exceções uma relação desses grupos com as divisões biogeográficas da entomofauna da América Latina. Desta forma, a análise do ITS1 corrobora resultados anteriores indicando que há claramente três entidades do complexo fraterculus no Brasil (A. sp.1, A. sp.2 e A. sp.3) e que diferentes morfotipos devem existir nas diferentes regiões da América Latina. / Fruit flies of Tephritidae family are important pest for the worldwide fruitculture because many species use commercial variety of fruits as host for the development of thier larval stage. Anastrepha is endemic of the American Continent and comprises about 200 described species, 90 of which occurs in Brazil. Among these species the most important is the nominal A. fraterculus, that, actually, comprises a complex of cryptic species, the so-called \"fraterculus complex\". Four species of the complex has been characterized, three of which occurs in Brazil (A.sp.1, A.sp.2, A. sp.3) and one in Ecuador (A. sp.4). In the present analyses the ITS1 spacer of the ribosomal genes was characterized by PCR and sequencing, in samples of A. fraterculus s.l. from several populations in Brazil and from different regions of South, Central America and Mexico. Amplyfication was carried out with primers designed in the present analyses, 18SF and 5.8SR, that generate fragments of 900 bp containing a partial sequence of the 18S gene, the complete ITS1 and the initial portion of the 5.8S gene. The length of the fragment did not varied significantly among the samples. The ITS1 size varied from 539 to 584 bp, and contained a very high content of AT, from 77.6 to 88.6 %, among samples. Similarity of the ITS1 sequences was high (from 88% to 99.8%) among the samples, and no signficant intraspecific differences were found in the sequences of samples from different brazilian populations. The POY software produced many parcimonious phylogenetic trees, and the strict consensus tree grouped the samples in distinct clades. First, there was a separation of the clade of Ceratitis species (outgroups) from the clade of Anastrepha. Within this clade A. obliqua was isolated from a large clade containg all the samples of A. fraterculus s.l.. Within A. fraterculus, one clade grouped the samples from Mexico and Guatemala, another clade the samples from Ecuador and Peru and a clade with the samples from Brazil and Argentina. The sample of Colombia was found as independent branch of the tree. In each of these clades there were subgroups of the different samples, and it was observed a relationship of these clades and subgroups to the biogeographic divisions of the entomofauna of Latin America with a few exceptions. The analysis of ITS1 clearly corroborate previous data indicating that there are three biological entities of the fraterculus complex in Brazil. It also indicates that different entities must exist in other regions of Latin America.
362

Avaliação do tratamento de efluente líquido gerado em usina termelétrica usando zeólita de cinzas de carvão / Evaluation of treatment of coal ash landfill leachate produced in thermoelectric using zeolitic materials from coal combustion by-products

Caio da Silva Miranda 13 November 2018 (has links)
As indústrias lançam diversos poluentes no meio ambiente. Dentre os poluentes destacam-se os elementos tóxicos presentes em efluentes líquidos por acarretarem alto risco potencial à saúde humana e ao meio ambiente. Os efluentes podem ser tratados por materiais adsorventes, os quais podem ser provindos de resíduos industriais. Uma forma de contribuir significativamente na sustentabilidade de uma indústria é a transformação de um de seus resíduos em sub-produto de valor agregado para aplicação no tratamento de seus efluentes líquidos como adsorvente de baixo custo. O objetivo deste trabalho foi sintetizar, e caracterizar zeólitas de cinzas de carvão e avaliar sua aplicação como material adsorvente no tratamento de efluente. Os materiais zeolíticos derivados de três tipos diferentes de cinzas de carvão (cinzas manga, cinzas ciclone e cinzas pesadas) geradas na usina termelétrica de Figueira-PR foram usados para tratar o lixiviado do aterro de cinzas de carvão da mesma usina. As seguintes características das zeólitas foram determinadas: composição mineralógica, composição química, teor de carbono total, análise morfológica, área superficial específica, capacidade de troca catiônica (CTC), perda ao fogo, pH, condutividade e densidade aparente. A fase zeolítica formada foi do tipo sodalita com as três amostras usadas como matéria prima após ativação hidrotérmica alcalina. O material zeolítico de cinzas manga apresentou a menor relação SiO2/Al2O3 (1,46), maior CTC (2,36 meq g-1) e área superficial específica (69,5 m2 g-1) e, consequentemente, maior capacidade de remoção dos íons do efluente. As concentrações de As e Cr estavam acima do padrão de lançamento de efluentes. As três amostras de materiais zeolíticos apresentaram uma remoção significativa de Ni, Cd, Zn e Co na dose de 10 g.L-1. Os materiais zeolíticos das cinzas manga e ciclone foram eficientes para reduzir a concentração de As abaixo do limite imposto pela legislação, enquanto a remoção do Cr não foi efetiva com nenhum dos materiais. Na segunda etapa do trabalho, as zeólitas foram modificadas com o surfactante brometo de hexadeciltrimetilamônio (HTDMA-Br) em concentrações de 1,8 e 20 mmol L-1. A modificação das zeólitas não melhorou a eficiência de remoção do As. A remoção do Cr usando a amostra de zeólita de cinzas manga modificada com HDTMA-Br 20 mmol L-1 resultou em uma concentração final muito próxima ao limite permitido pela legislação. / The industries release various types of pollutants into to the environment. Among these pollutants are the liquid effluents containing toxic elements, they carry a high potential risk to human health and the environment. Some effluents can be treated by adsorbent materials, which can be made from industrial waste. One way to contribute significantly to the sustainability of an industry is to transform one of its residues into a value-added by-product and use in the treatment of its own liquid effluents as a low cost adsorbent. The objective of this estudy was to synthesize and characterize coal ash zeolites and evaluate their application as adsorbent material in the treatment of effluent. Zeolite materials derived from three different types of coal ash (fly ashes, cyclone ashes and heavy ashes) generated at the Figueira-PR thermoelectric plant were used to treat leachate from the coal ash landfill of the same plant. The following zeolite characteristics were determined: mineralogical composition, chemical composition, total carbon content, morphological analysis, specific surface area, cation exchange capacity (CTC), fire loss, pH, conductivity and bulk density. The zeolite phase formed with the three samples used as raw material after alkaline hydrothermal activation was sodalite. The zeolite material from fly ash had the lowest SiO2/Al2O3 ratio (1.46), higher CTC (2.36 meq g-1) and specific surface area (69.5 m2 g-1) and, consequently, greater effluent removal capacity. The As and Cr concentrations were above the effluent discharge standard. The three samples of zeolitic materials showed a significant removal of Ni, Cd, Zn and Co in the dose of 10 g L-1. The zeolite materials from fly and cyclone ash were efficient to reduce As concentrations below the limit imposed by legislation, while removal of Cr was not effective with any of the materials. In the second stage of the study, the zeolites were modified with the surfactant hexadecyltrimethylammonium bromide (HTDMA-Br) in concentrations of 1.8 and 20 mmol.L-1. The zeolite removal efficiency of As did not improve after its modification. Removal of Cr using the 20 mmol.L-1 modified HDTMA-Br modified fly ash zeolite sample resulted in a final concentration very close to the limit allowed by the legislation.
363

Trout Fishing in the Smokies and the Blue Ridge, 1880-Present: How-To, History, and Habitat

Skaggs, Nathaniel Cole 01 May 2017 (has links)
This study focuses on trout fishing in the Great Smoky Mountains and the Blue Ridge Mountains from 1880 to 2017. I begin with a collection of personal narratives of fly-fishing in Tennessee to portray the allure of southern Appalachia trout fishing. I then describe the transition from native Cherokee fishing practices to sport fishing in the Smokies and the Blue Ridge by 1880. I explore a brief history of the National Parks and the United States Forest Service during the early 1900s, and address European fly-fishing influences in the United States during the twentieth century. I examine the habitats of the rainbow trout (oncorhynchus mykiss) and the native brook trout (salvelinus fontinalis) to provide an analysis on inter-species relationship between rainbow and brook trout in mountain streams. I then give an overview of important trout literature in the Smokies and the Blue Ridge through the twentieth and twenty-first centuries.
364

Performance of No Vibration/No Admixture Masonry Grout Containing High Replacement of Portland Cement with Fly Ash and Ground Granulated Blast Furnace Slag

Bateman, Eric 01 February 2014 (has links)
When hollow concrete masonry is used for construction in high seismic regions, structural designs typically require fully grouted walls. The grouting process is labor-intensive, time-consuming and has a high energy demand due to requirements of consolidation in each and subsequent grout lifts. Self-consolidating grout with admixtures has been successfully used without segregation in walls of up to 12.67 ft. in height. Investigation of self-consolidating grout mixes without admixtures has potential for sustainability improvement. This thesis reports on the compression strength and consolidation observations of self-consolidating characteristics of no vibration/no admixture grout made by substituting various proportions of Portland cement with Type F fly ash and/or ground granulated blast furnace slag (GGBFS). The percentages of Portland cement replacement evaluated were 0%, 50%, 60%, and 70% for Type F fly ash. The percentages of Portland cement replacement evaluated were 0%, 60%, 70% and 80% for Type F fly ash and GGBFS. Grout compressive strengths were evaluated from individually filled grout specimens constructed in concrete masonry hollow core units, dry cured, and tested after 7, 14, 28, 42, 56, and 130 days. Also, hollow concrete masonry walls were built 12.67 ft. tall and grouted. The relative performance was assessed by comparing to conventional grouted masonry and evaluating consolidation characteristics around mortar fins and reinforcement; compressive strength tests after 130 days of curing, and rebar pull-out tests were taken from various wall heights. All experimental grouts had acceptable consolidation characteristics but fly ash replacement grouts did not meet the compressive strength requirements.
365

Biological Treatment of Leachates of Microaerobic Fermentation

Alattar, Manar Arica 01 January 2012 (has links)
Microaerobic fermentation (MF) is a process of controlled degradation of organic waste material that occurs in enclosed fermentors under micro-aerobic conditions at near-room temperature. MF processing of vegetal materials progresses to endpoints in about 2-5 weeks. During MF processing, an acidic leachate rich in organic acids and alcohols is produced. The research presented in this thesis focuses on the efficiency of MF pre-processing of feedstock containing fibrous lignocellulosic (FLC) materials; efficiency of microbial and insect larvae-based treatments of MF leachate; tolerance of the Black Soldier fly larvae (BSFL) to various biological inhibitors common in leachate; and effectiveness of using MF and BSFL solid and liquid processing products as agricultural fertilizers. Results indicate that MF is unsuitable for pre-processing of FLC materials. Enhanced MF leachate treatment may increase efficiency of FLC processing though. Leachate can be efficiently treated using BSFL which decrease overall leachate toxicity. BSFL are able to tolerate increased levels of many of the biological inhibitors within the leachate including ethanol, acetate, pH extremes and temperature. MF solid residues increased corn plant growth when amended into soil, but residues resulting from BSFL processing of solid organics stunted corn plant growth. Short-term phytotoxicity of MF leachate was eliminated by diluting it 10 - 10,000 times or through BSFL processing. It can be concluded that MF processing of organics is beneficial for producing solid soil amendments from non-FLC materials and that dilution or BSFL treatment of MF leachate leads to a beneficial liquid fertilizer.
366

Studies of fly ash-based geopolymer concrete

Hardjito, Djwantoro January 2005 (has links)
The use of Portland cement in concrete construction is under critical review due to high amount of carbon dioxide gas released to the atmosphere during the production of cement. In recent years, attempts to increase the utilization of fly ash to partially replace the use of Portland cement in concrete are gathering momentum. Most of this by-product material is currently dumped in landfills, creating a threat to the environment. Geopolymer concrete is a ‘new’ material that does not need the presence of Portland cement as a binder. Instead, the source of materials such as fly ash, that are rich in Silicon (Si) and Aluminium (Al), are activated by alkaline liquids to produce the binder. Hence concrete with no Portland cement. This thesis reports the details of development of the process of making fly ash-based geopolymer concrete. Due to the lack of knowledge and know-how of making of fly ashbased geopolymer concrete in the published literature, this study adopted a rigorous trial and error process to develop the technology of making, and to identify the salient parameters affecting the properties of fresh and hardened concrete. As far as possible, the technology that is currently in use to manufacture and testing of ordinary Portland cement concrete were used. Fly ash was chosen as the basic material to be activated by the geopolimerization process to be the concrete binder, to totally replace the use of Portland cement. The binder is the only difference to the ordinary Portland cement concrete. To activate the Silicon and Aluminium content in fly ash, a combination of sodium hydroxide solution and sodium silicate solution was used. Manufacturing process comprising material preparation, mixing, placing, compaction and curing is reported in the thesis. / Napthalene-based superplasticiser was found to be ii useful to improve the workability of fresh fly ash-based geopolymer concrete, as well as the addition of extra water. The main parameters affecting the compressive strength of hardened fly ash-based geopolymer concrete are the curing temperature and curing time, the molar H2O-to-Na2O ratio, and mixing time. Fresh fly ash-based geopolymer concrete has been able to remain workable up to at least 120 minutes without any sign of setting and without any degradation in the compressive strength. Providing a rest period for fresh concrete after casting before the start of curing up to five days increased the compressive strength of hardened concrete. The elastic properties of hardened fly ash-based geopolymer concrete, i,e. the modulus of elasticity, the Poisson’s ratio, and the indirect tensile strength, are similar to those of ordinary Portland cement concrete. The stress-strain relations of fly ash-based geopolymer concrete fit well with the expression developed for ordinary Portland cement concrete.
367

Utilising waste products from Kwinana industries to manufacture low specification geopolymer concrete

Slabbert, Michael Charles January 2008 (has links)
One technology that makes concrete without cement and does not have the associated carbon footprint is geopolymer concrete. This technology utilizes waste fly ash from power stations and mixes it with activating chemicals to form a binder with similar or better properties than cement. Not only does this technology directly reduce carbon emissions by replacing cement it also utilizes the waste bi-product from power stations and prevents it from going to landfill. Concrete is composed of coarse aggregates, sand and cementitious paste. It seemed possible to make geopolymer concrete from 100% waste. The aggregates would come from recycled concrete and hard brittle bottom ash from power stations, the sand would come from foundries and the fly ash binder would also come from the same power station as the bottom ash. All of these materials are waste and would all be dumped in landfill. Where would one find all these waste materials in one place? The industrial suburb of Kwinana outside Perth is home to a large number of industries producing all these wastes. To find products that have a specification that these materials would suit was a material with a relatively low specification, one such specification is the concrete masonry units’ specification. For this to be adopted the mix design would then have to be altered to a drier type mix without any slump. As recycling facilities do not make a range of products it was decided to crush the aggregates in the laboratory specifically for this research and to blend all the waste materials. Numerous combinations were blended, analysed and assessed to establish which blends would best suit the aims and scope of this research. Eventually three blends were selected that encompassed all the waste products. / To find the right mix design proved challenging as these masonry products generally require a mix to have zero slump. It was decided to test across all the known and analysed water to geopolymer solids ratios for each of the mixes and establish the best mix based on compressive strength, workability and slump A known mix design based on research into low calcium Class F geopolymer concrete, developed at Curtin University using natural aggregates, was applied to these selected recycled waste mix designs. The benefit was to be able to compare the results of this research to a known result. Flash setting, an unknown phenomenon in geopolymer concrete, did occur in the low water mixes, but in spite of this, geopolymer concrete was successfully manufactured. The compressive strengths were substantially lower than those of the design mix and more research is required in this regard, however an indirect relationship was observed between the amount of bottom ash and the compressive strength. The high degree of LOI (loss of ignition) in both ashes, porosity of recycled aggregates, angularity, degree of fineness of the fines and flash setting are all possible factors influencing the properties of the geopolymer concrete. More research is recommended in a number of these areas to be able to understand and develop this technology further in order to make this a practical and robust technology in the quest to find solutions to our warming planet and our changing climate.
368

Ecology of the Fergusonina fly and Fergusobia nematode gall association in South Australia.

Head, Elise January 2008 (has links)
Attempts were made to grow Fergusobia nematodes in a dual aseptic culture with Eucalyptus camaldulensis. Callus tissue was grown from E. camaldulensis stem pieces in aseptic conditions. Calli were prone to deterioration after 14 days unless transferred to fresh growth medium. Lower levels of solutes (25% Murashige and Skoog salts, 25% plant vitamins and 0.5% sucrose) were more successful than published concentrations. Fergusobia J2 nematodes were surface sterilised with either Hibitane or washed with water to prepare them for inoculation of callus (Hay, 1994). Fergusobia subsequently recovered from plates of callus were all dead, which raised questions of how the nematodes are suited to Murashige and Skoog salt solutions. The survival of Fergusobia in aqueous solutions was then observed. It has been assumed that Fergusobia live about 2 days after dissection. Amphimictic nematodes from E. camaldulensis axial bud galls were used for a survival study. Nematodes lived for as long as 12 days in fresh tap water and 11 days in 1% M.S. solution. They were more active in tap water than in 1% M.S. solution. Nematodes in a dish together with dissected gall material died within 2 days. Nematodes in a separate dish with fresh tap water and clean gall fibres were observed to gather around the fibres. Observations of Fergusobia could be made within fresh solutions providing deteriorating gall tissues were removed from the dish. Gall production was attempted on E. camaldulensis grown in the glasshouse. These tree saplings were pruned to encourage new growth and periodically treated for infestations of scale insects leading to growth of sooty mould. Two forms of cage construction were used: (1) 1 m ³ screened cages and (2) acetate sleeves as used by Goolsby et al., 2000. Within the 1 m ³ cages containing flies, the growing points on saplings were blackened, possibly due to over-exploitation by ovipositing flies. One growing point caged in an acetate sleeve showed oviposition scars but did not produce a mature gall. Production of galls in the glasshouse was hindered by a lack in coincidence of flies emerging from mature galls and the flush of new growth following pruning. The production of galls within the glasshouse was not achieved. The phenology of E. camaldulensis, a host for the Fergusonina/Fergusobia mutualism, and gall ecology were observed in a two-year, non-destructive, field study in the Urrbrae Wetlands, Adelaide, South Australia. Tree growth and gall development was observed in the lower regions (0 – 2 m) of young trees. Three bud forms, terminal leaf bud, axial leaf bud and flower bud galls were monitored on the trees. The densities of galls were highly seasonal. Greatest density of growing points, axial leaf bud and flower bud galls occurred mostly during mid-winter to spring, whereas that of terminal leaf bud galls occurred during mid-spring to summer. Galling of flower buds did not appear to influence flowering and more flower buds and flowers occurred in the second year of the study as the trees matured. Trees mostly had medium (30-70%) levels of leaf damage, but there were seasonal trends in damage levels. Low scores for leaf damage were associated with increases in flower bud and flower production. Leaf damage, including sooty mould, appeared to increase during the cooler winter months. There were no significant seasonal relationships between levels of leaf damage and either growing point density or the occurrence of galls. When trees were compared with each other, those with lower leaf damage were more likely to have more growing points. The appearance of the canopy and the likelihood of a tree to have galls varied greatly between the trees. One tree was particularly susceptible to leaf attack, rarely had new leaves and produced no mature galls during the study. The colouring of leaves varied between trees, which indicates possible genetic variations causing some trees to be more likely hosts for Fergusonina/Fergusobia. Both new vegetative growth and terminal leaf bud galls were concentrated on the northern and eastern quadrants. Axial leaf bud and flower bud galls occurred more on the western or southern quadrants where they were possibly more protected from sun exposure on the northern or eastern quadrants. Axial galls on the northern side of one tree became reddened while those in the southern and western quadrants remained green. Reddening of axial galls may increase their likelihood of parasitism and predation by birds. Each of the three gall forms occurred within certain positions in the canopy. The tree host resource is partitioned effectively, with the three gall forms occurring on three different host structures. Additionally, the two vegetative forms terminal leaf bud and axial leaf bud galls occur on different shoot regions and in different seasons. The numbers of the galls is probably also affected by biotic and climatic influences. Parasitism, plant canopy shading, nutrient levels and host genetics are possible influences. Assuming an interval of 4 weeks between oviposition and first observation within the current study, terminal leaf bud galls had an average longevity of 11 weeks and axial leaf bud galls an average longevity of 14 weeks. Flower bud galls had longevities of 14 to 27 weeks from oviposition to senescence, assuming an interval of 6 weeks between oviposition and first observation within the current study. Flowers and flower buds occur irregularly within the eucalypts so it would be advantageous for flies and nematodes developing within flower bud galls to have extended or variable longevities to allow fly emergences to coincide with new flower buds. Not all of the galls recorded matured to produce adult flies. Nearly half of the terminal leaf bud galls initiated were aborted, recorded as absent, parasitised or eaten (45% of initiated galls). Of the three gall forms, they were the most prone to obvious parasitism and as many as 12 hymenopteran species have been reared from terminal leaf bud galls on E. camaldulensis (Taylor et al., 1996). These galls obviously provide a resource for many species within multiple trophic levels. Fourteen percent of axial leaf bud galls were absent or eaten and birds were seen breaking off and feeding on the galls. More than half (55%) of the initiated flower bud galls disappeared during the period of observation, possibly due to the foraging of birds. Destructive sampling and rearing out of parasitoids from both axial leaf bud and flower bud gall forms is needed to establish what species exist within them. Terminal leaf bud galls ranged from 7.5 to 30.1 mm in diameter and 10.0 to 43.6 mm in length. Flower bud gall size varied, with the largest being 15.0 mm by 22.3 mm. Axial leaf bud galls, ranged from 2.6 to 13.0 mm in diameter and length ranged from 2.3 to 10.5 mm. The larger axial leaf bud galls were nodular and appeared to have multiple locules. Destructive sampling and rearing out of flies is needed to establish the relationship between size and numbers of flies emerging. Terminal leaf bud galls increased in size, including many locules and exit holes per gall. Axial leaf bud galls were much smaller than the terminal leaf bud galls and 99% had only one to three exit holes. The rounded shape and presence of few locules within the axial leaf bud galls indicate that this form is limited to a shape and size producing few flies. The observation of greater size of terminal leaf bud galls suggests that these galls may have multiple foundresses. Twelve of the 13 flower bud galls with exit holes had either one or two holes. In flower bud galls on E. camaldulensis. the operculum remains sealed and the characteristic Fergusonina “window” appears at the side of the flower bud before fly emergence through a single hole. Destructive sampling is also necessary to determine parasitism of each of the gall forms. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1331016 / Thesis (M.Sc.) -- University of Adelaide, School of Agriculture, Food and Wine, 2008
369

Ecology of the Fergusonina fly and Fergusobia nematode gall association in South Australia.

Head, Elise January 2008 (has links)
Attempts were made to grow Fergusobia nematodes in a dual aseptic culture with Eucalyptus camaldulensis. Callus tissue was grown from E. camaldulensis stem pieces in aseptic conditions. Calli were prone to deterioration after 14 days unless transferred to fresh growth medium. Lower levels of solutes (25% Murashige and Skoog salts, 25% plant vitamins and 0.5% sucrose) were more successful than published concentrations. Fergusobia J2 nematodes were surface sterilised with either Hibitane or washed with water to prepare them for inoculation of callus (Hay, 1994). Fergusobia subsequently recovered from plates of callus were all dead, which raised questions of how the nematodes are suited to Murashige and Skoog salt solutions. The survival of Fergusobia in aqueous solutions was then observed. It has been assumed that Fergusobia live about 2 days after dissection. Amphimictic nematodes from E. camaldulensis axial bud galls were used for a survival study. Nematodes lived for as long as 12 days in fresh tap water and 11 days in 1% M.S. solution. They were more active in tap water than in 1% M.S. solution. Nematodes in a dish together with dissected gall material died within 2 days. Nematodes in a separate dish with fresh tap water and clean gall fibres were observed to gather around the fibres. Observations of Fergusobia could be made within fresh solutions providing deteriorating gall tissues were removed from the dish. Gall production was attempted on E. camaldulensis grown in the glasshouse. These tree saplings were pruned to encourage new growth and periodically treated for infestations of scale insects leading to growth of sooty mould. Two forms of cage construction were used: (1) 1 m ³ screened cages and (2) acetate sleeves as used by Goolsby et al., 2000. Within the 1 m ³ cages containing flies, the growing points on saplings were blackened, possibly due to over-exploitation by ovipositing flies. One growing point caged in an acetate sleeve showed oviposition scars but did not produce a mature gall. Production of galls in the glasshouse was hindered by a lack in coincidence of flies emerging from mature galls and the flush of new growth following pruning. The production of galls within the glasshouse was not achieved. The phenology of E. camaldulensis, a host for the Fergusonina/Fergusobia mutualism, and gall ecology were observed in a two-year, non-destructive, field study in the Urrbrae Wetlands, Adelaide, South Australia. Tree growth and gall development was observed in the lower regions (0 – 2 m) of young trees. Three bud forms, terminal leaf bud, axial leaf bud and flower bud galls were monitored on the trees. The densities of galls were highly seasonal. Greatest density of growing points, axial leaf bud and flower bud galls occurred mostly during mid-winter to spring, whereas that of terminal leaf bud galls occurred during mid-spring to summer. Galling of flower buds did not appear to influence flowering and more flower buds and flowers occurred in the second year of the study as the trees matured. Trees mostly had medium (30-70%) levels of leaf damage, but there were seasonal trends in damage levels. Low scores for leaf damage were associated with increases in flower bud and flower production. Leaf damage, including sooty mould, appeared to increase during the cooler winter months. There were no significant seasonal relationships between levels of leaf damage and either growing point density or the occurrence of galls. When trees were compared with each other, those with lower leaf damage were more likely to have more growing points. The appearance of the canopy and the likelihood of a tree to have galls varied greatly between the trees. One tree was particularly susceptible to leaf attack, rarely had new leaves and produced no mature galls during the study. The colouring of leaves varied between trees, which indicates possible genetic variations causing some trees to be more likely hosts for Fergusonina/Fergusobia. Both new vegetative growth and terminal leaf bud galls were concentrated on the northern and eastern quadrants. Axial leaf bud and flower bud galls occurred more on the western or southern quadrants where they were possibly more protected from sun exposure on the northern or eastern quadrants. Axial galls on the northern side of one tree became reddened while those in the southern and western quadrants remained green. Reddening of axial galls may increase their likelihood of parasitism and predation by birds. Each of the three gall forms occurred within certain positions in the canopy. The tree host resource is partitioned effectively, with the three gall forms occurring on three different host structures. Additionally, the two vegetative forms terminal leaf bud and axial leaf bud galls occur on different shoot regions and in different seasons. The numbers of the galls is probably also affected by biotic and climatic influences. Parasitism, plant canopy shading, nutrient levels and host genetics are possible influences. Assuming an interval of 4 weeks between oviposition and first observation within the current study, terminal leaf bud galls had an average longevity of 11 weeks and axial leaf bud galls an average longevity of 14 weeks. Flower bud galls had longevities of 14 to 27 weeks from oviposition to senescence, assuming an interval of 6 weeks between oviposition and first observation within the current study. Flowers and flower buds occur irregularly within the eucalypts so it would be advantageous for flies and nematodes developing within flower bud galls to have extended or variable longevities to allow fly emergences to coincide with new flower buds. Not all of the galls recorded matured to produce adult flies. Nearly half of the terminal leaf bud galls initiated were aborted, recorded as absent, parasitised or eaten (45% of initiated galls). Of the three gall forms, they were the most prone to obvious parasitism and as many as 12 hymenopteran species have been reared from terminal leaf bud galls on E. camaldulensis (Taylor et al., 1996). These galls obviously provide a resource for many species within multiple trophic levels. Fourteen percent of axial leaf bud galls were absent or eaten and birds were seen breaking off and feeding on the galls. More than half (55%) of the initiated flower bud galls disappeared during the period of observation, possibly due to the foraging of birds. Destructive sampling and rearing out of parasitoids from both axial leaf bud and flower bud gall forms is needed to establish what species exist within them. Terminal leaf bud galls ranged from 7.5 to 30.1 mm in diameter and 10.0 to 43.6 mm in length. Flower bud gall size varied, with the largest being 15.0 mm by 22.3 mm. Axial leaf bud galls, ranged from 2.6 to 13.0 mm in diameter and length ranged from 2.3 to 10.5 mm. The larger axial leaf bud galls were nodular and appeared to have multiple locules. Destructive sampling and rearing out of flies is needed to establish the relationship between size and numbers of flies emerging. Terminal leaf bud galls increased in size, including many locules and exit holes per gall. Axial leaf bud galls were much smaller than the terminal leaf bud galls and 99% had only one to three exit holes. The rounded shape and presence of few locules within the axial leaf bud galls indicate that this form is limited to a shape and size producing few flies. The observation of greater size of terminal leaf bud galls suggests that these galls may have multiple foundresses. Twelve of the 13 flower bud galls with exit holes had either one or two holes. In flower bud galls on E. camaldulensis. the operculum remains sealed and the characteristic Fergusonina “window” appears at the side of the flower bud before fly emergence through a single hole. Destructive sampling is also necessary to determine parasitism of each of the gall forms. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1331016 / Thesis (M.Sc.) -- University of Adelaide, School of Agriculture, Food and Wine, 2008
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Formation and degradation of PCDD/F in waste incineration ashes

Lundin, Lisa January 2007 (has links)
<p>The disposal of combustible wastes by incineration is a controversial issue that is strongly debated by both scientists and environmental activists due to the resulting emissions of noxious compounds, including (<i>inter alia</i>) polychlorinated dibenzo-<i>p</i>-dioxins (PCDDs), dibenzofurans (PCDFs), heavy metals and acid gases like sulfur dioxide. Currently available air pollution control devices are capable of effectively cleaning flue gases, and PCDD/F emissions to air from modern municipal solid waste (MSW) incinerators are low. However, the PCDD and PCDF end up in ash fractions that, in Sweden, are usually deposited in landfills.</p><p>The European Union has recently set a maximum permitted total concentration of 15 µg TEQ/kg for PCDD/F species in waste. Fly ash from municipal solid waste (MSW) incineration containing PCDD/Fs at concentrations above this limit will have to be remediated to avoid disposing of them in landfills; an expensive and environmentally unfriendly option. Therefore, effective, reliable and cost-effective methods for degrading PCDD/F in fly ash are required, and a better understanding of the behavior of PCDDs and PCDFs during thermal treatment will be needed to develop them.</p><p>In the studies this thesis is based upon both the formation and degradation of PCDDs and PCDFs in ashes from MSW incineration were studied.</p><p>The main findings of the investigations regarding PCCD/F formation were:</p><p>- The concentrations of PCDD and PCDF in fly ash increased with reductions in the temperature in the post-combustion zone.</p><p>- The homologue profile in the ash changed when the temperature in the post-combustion zone changed.</p><p>- The final amounts of PCDD and PCDF present were affected by their rates of both formation and degradation, and the mechanisms involved differ between PCDDs and PCDFs.</p><p>The main findings from the degradation studies were:</p><p>- The chemical composition of ash has a major impact on the degradation potential of PCDD and PCDF.</p><p>- The presence of oxygen during thermal treatment can enhance the degradation of PCDD and PCDF.</p><p>- Thermal treatment is a viable option for degrading PCDD and PCDF in ashes from MSW.</p><p>- Shifts in chlorination degree occur during thermal treatment.</p><p>- Rapid heat transfer into the ash is a key factor for ensuring fast degradation of PCDD and PCDF.</p><p>- Degradation of other chlorinated organic compounds, e.g. PCB and HCB, also occurs during thermal treatment of ash.</p><p>- Reductions in levels of PCDD and PCDF were not solely due to their desorption to the gas phase.</p><p>- Differences between the behavior of 2378-substituted congeners of PCDD and PCDF and the other congeners during thermal treatment were observed.</p><p>- Differences in isomer patterns of both PCDD and PCDF were observed between the ash and gas phases after thermal treatment at both 300 and 500 oC.</p><p>Overall, the results show that the formation and degradation mechanisms of PCDDs differ substantially from those of PCDFs. Thus these groups of compounds should be separately considered in attempts to identify ways to reduce their concentrations.</p>

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