This research studies the properties of self-compacting concrete by applying bamboo-charcoal to improve the fresh concrete property, physical property and micro-scale property.Conventionally, the Pozzolanic materials used in the self-compacting concrete are fly ash and slag. They are used to replace part of the cement such that the flowing property and compacting property can reach the requirement of the self-compacting concrete. According to previous research the bamboo-charcoal can absorb part of water, and enhance the early strength of concrete. In this study, we use bamboo-charcoal to replace parts of the fine-aggregate in the mixture of self-compacting concrete. The replacement ratio is designed as 0‰,2‰,3‰,3.5‰,4‰ and 5‰. From the experimental test of fresh concrete property, we can evaluate whether the concrete mix design can achieve the requirements of self-compacting concrete. Test for the compressive strength development, water absorption and rapid chloride penetration test are performed to evaluate the physical property of concrete. In addition, the scanning electronic microscope photos are taken to examine the microstructure of the concrete. In our results, it is found that the best proportion of replacement is 3‰. The requirements of self-compacting concrete can be satisfied, and the development of strength is also good.

Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. Walter R. Tschinkel, Florida State University, College of Arts and Sciences, Dept. of Biological Science. Title and description from dissertation home page (viewed Sept. 24, 2004). Includes bibliographical references.

The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on March 24, 2010). Thesis advisor: Dr. Adrienne Walker Hoard, Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (p. 113-125).

Thesis (Ph.D.) - University of Queensland, 2004. / Includes bibliography.

Made available in DSpace on 2014-06-11T19:23:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-27Bitstream added on 2014-06-13T19:29:36Z : No. of bitstreams: 1 goncalves_tap_me_botfca.pdf: 2550368 bytes, checksum: 024d4159f78f351a8b6ce296e16b0311 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A Antracologia é uma ciência que se baseia na anatomia da madeira para realizar a análise e identificação de carvão vegetal. No Brasil, ela visa tradicionalmente obter dados paleoecológicos e paleoetnobotânicos, mas também conservacionistas e tecnológicos. As análises antracológicas são possíveis porque a estrutura do lenho se mantém no carvão, entretanto, variações morfométricas podem ocorrer. O presente estudo visa contribuir para um melhor entendimento do efeito da carbonização no lenho através da análise estrutural da anatomia antes e após carbonização. A escolha de espécies do cerrado deveu-se ao forte impacto que este bioma sofre pela devastação e, principalmente, pelo uso de suas espécies para a produção de carvão vegetal. A anatomia do lenho e do carvão obtido a 400ºC foram analisadas em amostras de Copaifera langsdorffii, Dalbergia violacea, Dimorphandra mollis, Stryphnodendron polyphyllum, Caryocar brasiliense, Couepia grandiflora, Tapirira guianensis, Qualea grandiflora, Vochysia tucanorum e Pouteria torta, todas provenientes do cerrado e apresentando tipos anatômicos distintos. Todos os resultados quantitativos foram comparados estatisticamente. A contração anisotrópica nos carvões foi evidenciada principalmente na redução do diâmetro tangencial dos vasos, que ocorreu em 70% das espécies, mas não foi o suficiente para aumentar significativamente sua frequência; o diâmetro da abertura das pontoações intervasculares praticamente se manteve; a frequência dos raios aumentou ligeiramente; a altura e a largura dos raios variaram bastante, sendo que os raios mais largos contraíram mais que os estreitos; o parênquima axial manteve, no carvão, características semelhantes às do lenho; as fibras dos carvões perderam a distinção das camadas das paredes celulares presentes no lenho, mas mantiveram dimensões semelhantes... / Anthracology, or charcoal analysis, is a science based on wood anatomy. In Brazil it traditionally studies palaeoenvironment and palaeoethnobotany, as well as nature conservancy and forestry technology. Anthracological analyses are possible due to the maintenance of wood structure in charcoal. The present study aims to contribute to a better knowledge of carbonization on wood anatomy. Fresh and charred cerrado woods samples were analyzed. The Brazilian cerrado is highly impacted by devastation, while its species are widely used for charcoal production. The latter were charred under 400ºC. The selected species present different anatomical characteristics: Copaifera langsdorffii, Dalbergia violacea, Dimorphandra mollis, Stryphnodendron polyphyllum, Caryocar brasiliense, Couepia grandiflora, Tapirira guianensis, Qualea grandiflora, Vochysia tucanorum, and Pouteria torta. All the quantitative data between wood and charcoal were statistically analyzed. The anisotropic pattern of contraction in charcoals was evident as 70% of the species presented a reduction in vessels tangential diameter. Vessel frequency increase, however, was not statistically significant. Intervessel pits apertures diameters were very closely between wood and charcoal. Rays frequency slightly increased; rays height and width were extremely variable. Larger rays contract more than narrow ones. Axial parenchyma retained, in charcoal, the same dimensions and shape of wood. Charcoal fibres presented indistinct cell wall layering, but retained similar dimensions of wood fibres. Carbonization under 400ºC caused only few changes between wood and charcoal, corroborating the assumption that wood anatomy and anthracology are two closely related sciences

La recherche de doctorat ici présentée porte sur l’histoire et sur l’évolution du paysage végétal montagnard nord-apenninique et de son lien avec les activités anthropiques qui l’ont façonné au fil du temps. Notre idée de thèse est née grâce au projet international AGRESPE (réseAu Gestion de Ressources Environnementales passéeS et Patrimonialisation paysagèrE), dirigé par Marie Bal du laboratoire de Géographie GEOLAB UMR/CNRS 6042 de l’Université de Limoges. Le travail de thèse a été mené en cotutelle avec l’Université de Modena et Reggio Emilia (Italie).Le paysage végétal des Apennins du Nord a fait l'objet de nombreuses recherches scientifiques sur le paléo-environnement, représentées surtout par des études polliniques (ex. Cruise 1990a, 1990b ; Lowe, 1992 ; Watson, 1996 ; Vescovi et al, 2010a, 2010a, 2010b ; Branch, 2013), mais il présente encore des lacunes sur les recherches paléoenvironnementales et paléoécologiques de haute résolution spatiale. À cause de facteurs liés aux conditions physiques de la montagne et aux intérêts des chercheurs, la recherche archéologique (notamment celle pastorale) n’est pas très développée par rapport aux études de la plaine (Fontana, 1997 ; Cardarelli et Malnati, 2006 ; Ferrari et al., 2006). Ce manque d'études sur les relations entre les sociétés et leur environnement dans les Apennins nous a donc encouragés à en découvrir davantage. Au sein de ce secteur montagnard nous avons choisi deux montagnes clés : le Monte Cimone et le Corno alle Scale. Faisant partie de deux parc régionaux, ces zones d’étude sont caractérisées par des hêtraies qui, jusqu’au milieu du XXe siècle, ont été gérées en taillis pour la production de bois de chauffage et de charbon. La limite altitudinale de la forêt est plus basse que celle écologique potentielle. Au Monte Cimone elle est localisée à 1700 m, tandis que dans la zone du Corno alle Scale elle est située à environ 1600 m. Au-dessus de la limite forestière il y a des bruyères à myrtille et des prairies qui, à l’instar du passé, sont aujourd’hui destinées au pâturage. / This PhD thesis concerns the reconstruction and the development of the Late Holocene plant landscape of two mountain areas of the Northern Apennines: the area of Monte Cimone and the area of Monte Corno alle Scale, located in the two regional parks. Previous research in the two study areas consists of quite numerous pollen analyses at regional scale while studies at local-scale, such as archaeoanthracology and pedoanthracology, are scarce.We have therefore decided to study these two mountain areas through pedoanthracology that is the taxonomic identification of wood charcoals contained in soils. Moreover, archaeoanthracology was applied to charcoal platforms and consists in the analysis of charcoals contained in the platforms which were used until the mid-20th century to produce charcoal. In the methodology used in this thesis are also included field surveys with the aim of locate and geolocalize ancient pastoral structures, witnesses of pastoral activities at high elevations.The main objectives of this research were: - to reconstruct the plant landscape; - to understand how human activities (e.g. pastoralism and forest exploitation) have transformed the landscape; to study the fire history; - to identify the variations of tree and timberline in the past.In the Monte Cimone area, nine pedoanthracological trenches were cut between 1650 m and 2078 m of elevation, and about 4000 charcoals were analyzed; moreover, 10 pastoral structures were found and georeferenced. In the Corno alle Scale area, eight pedoanthracological trenches were cut between 1600 m and 1860 m of elevation, and more than 2000 charcoals were analyzed; no pastoral structure were identified here. In each study area, four charcoal platforms were sampled with a total of 1200 charcoals analysed. Overall, 33 C14datings were performed on charcoals. Almost all C14 dates of soil charcoal are concentrated in the Late Holocene and only two are from the Early Holocene. The anthracomass of the low elevation sampling points (e.g. 962.8 mg/kg) is higher than the anthracomass of the high elevation sampling points (e.g. 1.6 mg/kg). The charcoals are evidence of the past presence of Ericaceae, Fabaceae, Juniperus sp., Abies alba, Quercus sp./Castanea sp., Prunus sp., Betula sp., Taxus baccata, Fagus sylvatica, Fraxinus sp. And Acer sp.The main results of this research show a plant landscape during the last 3000 years that is very similar to the current one with little variations in the tree and timberline. Charcoal platforms analysis has shown a beech charcoal production during the centuries between the 15th and mid-20th centuries. Estimation of the wood size used suggest a well-run exploitation of the timber resource. The two main activity in high mountain, pastoralism and charcoal production, seem to have played an important role in the shaping the current plant landscape.

?rea de concentra??o: Manejo florestal. / Data de aprova??o retirada da vers?o impressa da disserta??o. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-02-16T21:29:35Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) marcelino_breguez_goncalves_sobrinho.pdf: 1141104 bytes, checksum: ccb26c2686949cf99a1c9c1fcfca38e6 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-03-09T19:36:14Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) marcelino_breguez_goncalves_sobrinho.pdf: 1141104 bytes, checksum: ccb26c2686949cf99a1c9c1fcfca38e6 (MD5) / Made available in DSpace on 2018-03-09T19:36:14Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) marcelino_breguez_goncalves_sobrinho.pdf: 1141104 bytes, checksum: ccb26c2686949cf99a1c9c1fcfca38e6 (MD5) Previous issue date: 2016 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / O Brasil ? o maior produtor mundial de carv?o vegetal, sendo que os principais consumidores s?o os setores de ferro-gusa, a?o e ferro-ligas e, em menor escala, o com?rcio e o consumidor residencial. Um carv?o vegetal de boa qualidade para a produ??o de ferro-ligas deve apresentar densidade a granel acima de 250 Kg.m-3, carbono fixo em torno de 75%, teor de cinzas abaixo de 1%, aproximadamente 25% de materiais vol?teis, teor de umidade abaixo de 6%, baixo teor de finos e com boa resist?ncia mec?nica. Estas propriedades f?sicas, qu?micas e mec?nicas diminuem o custo e aumenta a qualidade das ligas de ferro. Objetivou-se com essa pesquisa avaliar as propriedades f?sicas do carv?o vegetal de Eucalyptus sp. e, a influ?ncia da qualidade deste na produ??o de ferro ligas. Foram analisadas amostras desta mat?ria prima em cen?rios diferentes para avaliar sua qualidade. Um cen?rio o carv?o vegetal era transportado em estrada de terra e no outro em estrada pavimentada. A pesquisa foi realizada no laborat?rio de qualidade de carv?o vegetal em uma empresa do litoral norte baiano. Determinou-se a densidade a granel (Kg.m-3), o tamanho m?dio das part?culas (mm) e o teor de finos (%) do carv?o vegetal. Os testes e as coletas foram executados de acordo com as respectivas normas da ABNT. As avalia??es mostraram que a qualidade do carv?o vegetal quanto ?s suas propriedades f?sicas s?o alteradas pelo manuseio e transporte do produto at? a f?brica na metalurgia. Em rela??o ao transporte da mat?ria prima em estrada de terra e asfalto n?o ocorreu diferen?a impactante de uma para outra. Logo, torna-se interessante padronizar o manuseio e a carboniza??o para que o carv?o vegetal sofra menos quedas pois, a gera??o de finos foi bastante representativa. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / Brazil is the largest producer of wood charcoal, and the main consumers are the sectors iron industries, steel and ferroalloys and, to a lesser extent, trade and residential consumers. The quality of charcoal depends directly on the physical, chemical and anatomical wood that originated it. A good quality wood charcoal for the production of ferroalloys must provide bulk density above 250 kg.m-3, fixed carbon about 75%, ash content below 1%, approximately 25% volatiles, moisture content below 6%, low fines content and good mechanical strength. These physical, chemical and mechanical properties decrease the cost and increase the quality of ferroalloys. The Brazilian segment of ferroalloys is fairly diverse and occupies a prominent position on the world stage. Among the factors that led to this condition relates to the availability of raw materials. We aimed to evaluate the quality of the wood charcoal used in the production of ferroalloys. Wood charcoal samples were evaluated in different canaries to assess their quality. The survey was conducted in wood charcoal quality laboratory in a company of Bahia north coast. It was determined bulk density (kg.m-3), the average particle size (mm) and a fines content (%). The evaluations showed that the quality of the physical properties of wood charcoal are changed by handling and transportation of the product to the plant in metallurgy. The transport on dirt road and asphalt was not an impressive point. Therefore, the greater the resistance charcoal, less impact its physical properties will suffer.

Fire is an important ecological feature across temperate forests, yet characteristics of the coast redwood fire regime remain uncertain due to generally few fire histories. This study examines legacies of fire in redwood forests in northern California through radiocarbon dating and quantification of soil macro-charcoal, soil carbon and pyrogenic carbon in old growth redwood stands. We sampled soils in the Headwaters Forest Reserve, a protected fragment of old growth redwood in Humboldt County, California. Radiocarbon dates from macro-charcoal indicate fire events occurring a maximum of 6,840 calibrated years BP, predating existing records. Composite 14C dates show increased fire activity within the last 1,000 years in synchrony with existing dendrochronological records. Soil C averaged 928 g/m2, of which a high proportion was pyrogenic C (15-30%). Information from this multi-proxy reconstruction clarifies our understanding of the nature of coast redwood fires, contributing to ongoing discussions of coast redwood fire management.

Made available in DSpace on 2014-06-11T19:35:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-15Bitstream added on 2014-06-13T20:07:12Z : No. of bitstreams: 1 abreu_gc_dr_guara.pdf: 4181088 bytes, checksum: eb2a9fc2114d10d93d945c3ea5bf9361 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O uso de biomassa renovável para a produção de carvão vegetal é uma das alternativas atuais de obtenção de agente redutor na siderurgia e possui características de neutralidade nas emissões de gases efeito estufa, uma vez que absorve o CO2 emitido durante o crescimento das florestas. O uso do carvão vegetal no processo de fabricação do sinter (sinterização) não é empregado atualmente na prática observada. Além disto, a sinterização consiste, dentro da siderurgia, em uma das etapas com maior potencial de impacto ambiental. Testes em escala piloto para produção de sinter foram conduzidos buscando avaliar diferentes participações de carvão vegetal na mistura de combustíveis com o intuito de quantificar o desempenho operacional e de qualidade de produto, bem como as variáveis ambientais decorrentes das emissões atmosféricas do processo. Foram avaliados os principais parâmetros ambientais, dentre eles, as emissões de dioxinas e furanos. Como resultados, obteve-se que é possível uma participação de até 50% de carvão vegetal na mistura de combustíveis com qualidade aceitável do sinter produto obtido, implicando em uma redução de até 50% nas emissões de gases efeito estufa, mesmo com maior emissão relativa de CH4. Uma redução de até 50% nas emissões de dioxinas e furanos também foi observada / Renewable biomass use for charcoal production is one of the current alternatives aiming the reduction agent supply at steel making process. This alternative has the greenhouse gases emission neutrality characteristics once it uses the emitted CO2 during the trees growing period. The use of charcoal at sinter making process is not commonly applied at current practices. In addition, sinter making process consists, among the other steel making steps, as one of the most potential environmental impact. Laboratory tests for sinter making were conducted aiming the evaluation of different participations of charcoal in fuel mix in order to quantify the operational performance and product quality as well as environmental variables resulting from process atmospheric emissions. The main environmental parameters were evaluated, among them, dioxins and furans. As a result, it was found that a participation of 50% of charcoal in the fuel mix is possible with acceptable quality of the final sinter product, and a reduction of greenhouse gases up to 50% even though a higher CH4 relative emission. Reductions of 50% at dioxins and furans emissions were also observed